Merge tag 'linux-can-next-for-3.16-20140519' of git://gitorious.org/linux-can/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2014-05-19

this is a pull request of 13 patches for net-next/master.

A patch by Dan Carpenter fixes a coccinelle warning in the mcp251x
driver. Jean Delvare contributes three patches to tightening the
Kconfig dependencies for some drivers. Then come three patches by Pavel
Machek that improve the c_can driver support on the socfpga platform.
Sergei Shtylyov's patch brings support for the CAN hardware found on
Renesas R-Car CAN controllers. Four patches by Oliver Hartkopp, the
first cleans up the guard macros in the CAN headers the other three
improve the EFF frame filtering. Maximilian Schneider's patch adds
support for the GS_USB CAN devices.

Signed-off-by: David S. Miller <davem@davemloft.net>

31 files changed, 2170 insertions, 95 deletions

diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt
index 2fa44cbe81b7..cdd381c5311d 100644
--- a/Documentation/networking/can.txt
+++ b/Documentation/networking/can.txt
@@ -469,6 +469,41 @@ solution for a couple of reasons:
   having this 'send only' use-case we may remove the receive list in the
   Kernel to save a little (really a very little!) CPU usage.
 
+  4.1.1.1 CAN filter usage optimisation
+
+  The CAN filters are processed in per-device filter lists at CAN frame
+  reception time. To reduce the number of checks that need to be performed
+  while walking through the filter lists the CAN core provides an optimized
+  filter handling when the filter subscription focusses on a single CAN ID.
+
+  For the possible 2048 SFF CAN identifiers the identifier is used as an index
+  to access the corresponding subscription list without any further checks.
+  For the 2^29 possible EFF CAN identifiers a 10 bit XOR folding is used as
+  hash function to retrieve the EFF table index.
+
+  To benefit from the optimized filters for single CAN identifiers the
+  CAN_SFF_MASK or CAN_EFF_MASK have to be set into can_filter.mask together
+  with set CAN_EFF_FLAG and CAN_RTR_FLAG bits. A set CAN_EFF_FLAG bit in the
+  can_filter.mask makes clear that it matters whether a SFF or EFF CAN ID is
+  subscribed. E.g. in the example from above
+
+    rfilter[0].can_id   = 0x123;
+    rfilter[0].can_mask = CAN_SFF_MASK;
+
+  both SFF frames with CAN ID 0x123 and EFF frames with 0xXXXXX123 can pass.
+
+  To filter for only 0x123 (SFF) and 0x12345678 (EFF) CAN identifiers the
+  filter has to be defined in this way to benefit from the optimized filters:
+
+    struct can_filter rfilter[2];
+
+    rfilter[0].can_id   = 0x123;
+    rfilter[0].can_mask = (CAN_EFF_FLAG | CAN_RTR_FLAG | CAN_SFF_MASK);
+    rfilter[1].can_id   = 0x12345678 | CAN_EFF_FLAG;
+    rfilter[1].can_mask = (CAN_EFF_FLAG | CAN_RTR_FLAG | CAN_EFF_MASK);
+
+    setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, &rfilter, sizeof(rfilter));
+
   4.1.2 RAW socket option CAN_RAW_ERR_FILTER
 
   As described in chapter 3.4 the CAN interface driver can generate so
diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
index 4aacaa9b478a..714b18790caf 100644
--- a/drivers/net/can/Kconfig
+++ b/drivers/net/can/Kconfig
@@ -65,7 +65,7 @@ config CAN_LEDS
 
 config CAN_AT91
 	tristate "Atmel AT91 onchip CAN controller"
-	depends on ARM
+	depends on ARCH_AT91 || COMPILE_TEST
 	---help---
 	  This is a driver for the SoC CAN controller in Atmel's AT91SAM9263
 	  and AT91SAM9X5 processors.
@@ -104,7 +104,7 @@ config CAN_FLEXCAN
 
 config PCH_CAN
 	tristate "Intel EG20T PCH CAN controller"
-	depends on PCI
+	depends on PCI && (X86_32 || COMPILE_TEST)
 	---help---
 	  This driver is for PCH CAN of Topcliff (Intel EG20T PCH) which
 	  is an IOH for x86 embedded processor (Intel Atom E6xx series).
@@ -119,6 +119,16 @@ config CAN_GRCAN
 	  endian syntheses of the cores would need some modifications on
 	  the hardware level to work.
 
+config CAN_RCAR
+	tristate "Renesas R-Car CAN controller"
+	depends on ARM
+	---help---
+	  Say Y here if you want to use CAN controller found on Renesas R-Car
+	  SoCs.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called rcar_can.
+
 source "drivers/net/can/mscan/Kconfig"
 
 source "drivers/net/can/sja1000/Kconfig"
diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index c42058868b0f..90f538c73f8c 100644
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -25,5 +25,6 @@ obj-$(CONFIG_CAN_JANZ_ICAN3)	+= janz-ican3.o
 obj-$(CONFIG_CAN_FLEXCAN)	+= flexcan.o
 obj-$(CONFIG_PCH_CAN)		+= pch_can.o
 obj-$(CONFIG_CAN_GRCAN)		+= grcan.o
+obj-$(CONFIG_CAN_RCAR)		+= rcar_can.o
 
 ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index a2ca820b5373..e154b4cb0f1a 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -252,8 +252,7 @@ static void c_can_obj_update(struct net_device *dev, int iface, u32 cmd, u32 obj
 	struct c_can_priv *priv = netdev_priv(dev);
 	int cnt, reg = C_CAN_IFACE(COMREQ_REG, iface);
 
-	priv->write_reg(priv, reg + 1, cmd);
-	priv->write_reg(priv, reg, obj);
+	priv->write_reg32(priv, reg, (cmd << 16) | obj);
 
 	for (cnt = MIN_TIMEOUT_VALUE; cnt; cnt--) {
 		if (!(priv->read_reg(priv, reg) & IF_COMR_BUSY))
@@ -328,8 +327,7 @@ static void c_can_setup_tx_object(struct net_device *dev, int iface,
 		change_bit(idx, &priv->tx_dir);
 	}
 
-	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface), arb);
-	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface), arb >> 16);
+	priv->write_reg32(priv, C_CAN_IFACE(ARB1_REG, iface), arb);
 
 	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), ctrl);
 
@@ -391,8 +389,7 @@ static int c_can_read_msg_object(struct net_device *dev, int iface, u32 ctrl)
 
 	frame->can_dlc = get_can_dlc(ctrl & 0x0F);
 
-	arb = priv->read_reg(priv, C_CAN_IFACE(ARB1_REG, iface));
-	arb |= priv->read_reg(priv, C_CAN_IFACE(ARB2_REG, iface)) << 16;
+	arb = priv->read_reg32(priv, C_CAN_IFACE(ARB1_REG, iface));
 
 	if (arb & IF_ARB_MSGXTD)
 		frame->can_id = (arb & CAN_EFF_MASK) | CAN_EFF_FLAG;
@@ -424,12 +421,10 @@ static void c_can_setup_receive_object(struct net_device *dev, int iface,
 	struct c_can_priv *priv = netdev_priv(dev);
 
 	mask |= BIT(29);
-	priv->write_reg(priv, C_CAN_IFACE(MASK1_REG, iface), mask);
-	priv->write_reg(priv, C_CAN_IFACE(MASK2_REG, iface), mask >> 16);
+	priv->write_reg32(priv, C_CAN_IFACE(MASK1_REG, iface), mask);
 
 	id |= IF_ARB_MSGVAL;
-	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface), id);
-	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface), id >> 16);
+	priv->write_reg32(priv, C_CAN_IFACE(ARB1_REG, iface), id);
 
 	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), mcont);
 	c_can_object_put(dev, iface, obj, IF_COMM_RCV_SETUP);
diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index c56f1b1c11ca..99ad1aa576b0 100644
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -78,6 +78,7 @@ enum reg {
 	C_CAN_INTPND2_REG,
 	C_CAN_MSGVAL1_REG,
 	C_CAN_MSGVAL2_REG,
+	C_CAN_FUNCTION_REG,
 };
 
 static const u16 reg_map_c_can[] = {
@@ -129,6 +130,7 @@ static const u16 reg_map_d_can[] = {
 	[C_CAN_BRPEXT_REG]	= 0x0E,
 	[C_CAN_INT_REG]		= 0x10,
 	[C_CAN_TEST_REG]	= 0x14,
+	[C_CAN_FUNCTION_REG]	= 0x18,
 	[C_CAN_TXRQST1_REG]	= 0x88,
 	[C_CAN_TXRQST2_REG]	= 0x8A,
 	[C_CAN_NEWDAT1_REG]	= 0x9C,
@@ -176,8 +178,10 @@ struct c_can_priv {
 	atomic_t tx_active;
 	unsigned long tx_dir;
 	int last_status;
-	u16 (*read_reg) (struct c_can_priv *priv, enum reg index);
-	void (*write_reg) (struct c_can_priv *priv, enum reg index, u16 val);
+	u16 (*read_reg) (const struct c_can_priv *priv, enum reg index);
+	void (*write_reg) (const struct c_can_priv *priv, enum reg index, u16 val);
+	u32 (*read_reg32) (const struct c_can_priv *priv, enum reg index);
+	void (*write_reg32) (const struct c_can_priv *priv, enum reg index, u32 val);
 	void __iomem *base;
 	const u16 *regs;
 	void *priv;		/* for board-specific data */
diff --git a/drivers/net/can/c_can/c_can_pci.c b/drivers/net/can/c_can/c_can_pci.c
index 58f71e1fcc4e..5d11e0e4225b 100644
--- a/drivers/net/can/c_can/c_can_pci.c
+++ b/drivers/net/can/c_can/c_can_pci.c
@@ -47,42 +47,59 @@ struct c_can_pci_data {
  * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
  * Handle the same by providing a common read/write interface.
  */
-static u16 c_can_pci_read_reg_aligned_to_16bit(struct c_can_priv *priv,
+static u16 c_can_pci_read_reg_aligned_to_16bit(const struct c_can_priv *priv,
 						enum reg index)
 {
 	return readw(priv->base + priv->regs[index]);
 }
 
-static void c_can_pci_write_reg_aligned_to_16bit(struct c_can_priv *priv,
+static void c_can_pci_write_reg_aligned_to_16bit(const struct c_can_priv *priv,
 						enum reg index, u16 val)
 {
 	writew(val, priv->base + priv->regs[index]);
 }
 
-static u16 c_can_pci_read_reg_aligned_to_32bit(struct c_can_priv *priv,
+static u16 c_can_pci_read_reg_aligned_to_32bit(const struct c_can_priv *priv,
 						enum reg index)
 {
 	return readw(priv->base + 2 * priv->regs[index]);
 }
 
-static void c_can_pci_write_reg_aligned_to_32bit(struct c_can_priv *priv,
+static void c_can_pci_write_reg_aligned_to_32bit(const struct c_can_priv *priv,
 						enum reg index, u16 val)
 {
 	writew(val, priv->base + 2 * priv->regs[index]);
 }
 
-static u16 c_can_pci_read_reg_32bit(struct c_can_priv *priv,
+static u16 c_can_pci_read_reg_32bit(const struct c_can_priv *priv,
 				    enum reg index)
 {
 	return (u16)ioread32(priv->base + 2 * priv->regs[index]);
 }
 
-static void c_can_pci_write_reg_32bit(struct c_can_priv *priv,
+static void c_can_pci_write_reg_32bit(const struct c_can_priv *priv,
 				      enum reg index, u16 val)
 {
 	iowrite32((u32)val, priv->base + 2 * priv->regs[index]);
 }
 
+static u32 c_can_pci_read_reg32(const struct c_can_priv *priv, enum reg index)
+{
+	u32 val;
+
+	val = priv->read_reg(priv, index);
+	val |= ((u32) priv->read_reg(priv, index + 1)) << 16;
+
+	return val;
+}
+
+static void c_can_pci_write_reg32(const struct c_can_priv *priv, enum reg index,
+		u32 val)
+{
+	priv->write_reg(priv, index + 1, val >> 16);
+	priv->write_reg(priv, index, val);
+}
+
 static void c_can_pci_reset_pch(const struct c_can_priv *priv, bool enable)
 {
 	if (enable) {
@@ -187,6 +204,8 @@ static int c_can_pci_probe(struct pci_dev *pdev,
 		ret = -EINVAL;
 		goto out_free_c_can;
 	}
+	priv->read_reg32 = c_can_pci_read_reg32;
+	priv->write_reg32 = c_can_pci_write_reg32;
 
 	priv->raminit = c_can_pci_data->init;
 
diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index 1df0b322d1e4..824108cd9fd5 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -40,6 +40,7 @@
 #define CAN_RAMINIT_START_MASK(i)	(0x001 << (i))
 #define CAN_RAMINIT_DONE_MASK(i)	(0x100 << (i))
 #define CAN_RAMINIT_ALL_MASK(i)		(0x101 << (i))
+#define DCAN_RAM_INIT_BIT		(1 << 3)
 static DEFINE_SPINLOCK(raminit_lock);
 /*
  * 16-bit c_can registers can be arranged differently in the memory
@@ -47,31 +48,31 @@ static DEFINE_SPINLOCK(raminit_lock);
  * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
  * Handle the same by providing a common read/write interface.
  */
-static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
+static u16 c_can_plat_read_reg_aligned_to_16bit(const struct c_can_priv *priv,
 						enum reg index)
 {
 	return readw(priv->base + priv->regs[index]);
 }
 
-static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
+static void c_can_plat_write_reg_aligned_to_16bit(const struct c_can_priv *priv,
 						enum reg index, u16 val)
 {
 	writew(val, priv->base + priv->regs[index]);
 }
 
-static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
+static u16 c_can_plat_read_reg_aligned_to_32bit(const struct c_can_priv *priv,
 						enum reg index)
 {
 	return readw(priv->base + 2 * priv->regs[index]);
 }
 
-static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
+static void c_can_plat_write_reg_aligned_to_32bit(const struct c_can_priv *priv,
 						enum reg index, u16 val)
 {
 	writew(val, priv->base + 2 * priv->regs[index]);
 }
 
-static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask,
+static void c_can_hw_raminit_wait_ti(const struct c_can_priv *priv, u32 mask,
 				  u32 val)
 {
 	/* We look only at the bits of our instance. */
@@ -80,7 +81,7 @@ static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask,
 		udelay(1);
 }
 
-static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
+static void c_can_hw_raminit_ti(const struct c_can_priv *priv, bool enable)
 {
 	u32 mask = CAN_RAMINIT_ALL_MASK(priv->instance);
 	u32 ctrl;
@@ -96,18 +97,68 @@ static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
 	ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
 	writel(ctrl, priv->raminit_ctrlreg);
 	ctrl &= ~CAN_RAMINIT_DONE_MASK(priv->instance);
-	c_can_hw_raminit_wait(priv, ctrl, mask);
+	c_can_hw_raminit_wait_ti(priv, ctrl, mask);
 
 	if (enable) {
 		/* Set start bit and wait for the done bit. */
 		ctrl |= CAN_RAMINIT_START_MASK(priv->instance);
 		writel(ctrl, priv->raminit_ctrlreg);
 		ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
-		c_can_hw_raminit_wait(priv, ctrl, mask);
+		c_can_hw_raminit_wait_ti(priv, ctrl, mask);
 	}
 	spin_unlock(&raminit_lock);
 }
 
+static u32 c_can_plat_read_reg32(const struct c_can_priv *priv, enum reg index)
+{
+	u32 val;
+
+	val = priv->read_reg(priv, index);
+	val |= ((u32) priv->read_reg(priv, index + 1)) << 16;
+
+	return val;
+}
+
+static void c_can_plat_write_reg32(const struct c_can_priv *priv, enum reg index,
+		u32 val)
+{
+	priv->write_reg(priv, index + 1, val >> 16);
+	priv->write_reg(priv, index, val);
+}
+
+static u32 d_can_plat_read_reg32(const struct c_can_priv *priv, enum reg index)
+{
+	return readl(priv->base + priv->regs[index]);
+}
+
+static void d_can_plat_write_reg32(const struct c_can_priv *priv, enum reg index,
+		u32 val)
+{
+	writel(val, priv->base + priv->regs[index]);
+}
+
+static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask)
+{
+	while (priv->read_reg32(priv, C_CAN_FUNCTION_REG) & mask)
+		udelay(1);
+}
+
+static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
+{
+	u32 ctrl;
+
+	ctrl = priv->read_reg32(priv, C_CAN_FUNCTION_REG);
+	ctrl &= ~DCAN_RAM_INIT_BIT;
+	priv->write_reg32(priv, C_CAN_FUNCTION_REG, ctrl);
+	c_can_hw_raminit_wait(priv, ctrl);
+
+	if (enable) {
+		ctrl |= DCAN_RAM_INIT_BIT;
+		priv->write_reg32(priv, C_CAN_FUNCTION_REG, ctrl);
+		c_can_hw_raminit_wait(priv, ctrl);
+	}
+}
+
 static struct platform_device_id c_can_id_table[] = {
 	[BOSCH_C_CAN_PLATFORM] = {
 		.name = KBUILD_MODNAME,
@@ -201,11 +252,15 @@ static int c_can_plat_probe(struct platform_device *pdev)
 		case IORESOURCE_MEM_32BIT:
 			priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
 			priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
+			priv->read_reg32 = c_can_plat_read_reg32;
+			priv->write_reg32 = c_can_plat_write_reg32;
 			break;
 		case IORESOURCE_MEM_16BIT:
 		default:
 			priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 			priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
+			priv->read_reg32 = c_can_plat_read_reg32;
+			priv->write_reg32 = c_can_plat_write_reg32;
 			break;
 		}
 		break;
@@ -214,6 +269,8 @@ static int c_can_plat_probe(struct platform_device *pdev)
 		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 		priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 		priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
+		priv->read_reg32 = d_can_plat_read_reg32;
+		priv->write_reg32 = d_can_plat_write_reg32;
 
 		if (pdev->dev.of_node)
 			priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
@@ -221,11 +278,20 @@ static int c_can_plat_probe(struct platform_device *pdev)
 			priv->instance = pdev->id;
 
 		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+		/* Not all D_CAN modules have a separate register for the D_CAN
+		 * RAM initialization. Use default RAM init bit in D_CAN module
+		 * if not specified in DT.
+		 */
+		if (!res) {
+			priv->raminit = c_can_hw_raminit;
+			break;
+		}
+
 		priv->raminit_ctrlreg = devm_ioremap_resource(&pdev->dev, res);
 		if (IS_ERR(priv->raminit_ctrlreg) || priv->instance < 0)
 			dev_info(&pdev->dev, "control memory is not used for raminit\n");
 		else
-			priv->raminit = c_can_hw_raminit;
+			priv->raminit = c_can_hw_raminit_ti;
 		break;
 	default:
 		ret = -EINVAL;
diff --git a/drivers/net/can/mscan/Kconfig b/drivers/net/can/mscan/Kconfig
index f19be5269e7b..81c711719490 100644
--- a/drivers/net/can/mscan/Kconfig
+++ b/drivers/net/can/mscan/Kconfig
@@ -1,5 +1,5 @@
 config CAN_MSCAN
-	depends on PPC || M68K
+	depends on PPC
 	tristate "Support for Freescale MSCAN based chips"
 	---help---
 	  The Motorola Scalable Controller Area Network (MSCAN) definition
diff --git a/drivers/net/can/rcar_can.c b/drivers/net/can/rcar_can.c
new file mode 100644
index 000000000000..5268d216ecfa
--- /dev/null
+++ b/drivers/net/can/rcar_can.c
@@ -0,0 +1,876 @@
+/* Renesas R-Car CAN device driver
+ *
+ * Copyright (C) 2013 Cogent Embedded, Inc. <source@cogentembedded.com>
+ * Copyright (C) 2013 Renesas Solutions Corp.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/platform_device.h>
+#include <linux/can/led.h>
+#include <linux/can/dev.h>
+#include <linux/clk.h>
+#include <linux/can/platform/rcar_can.h>
+
+#define RCAR_CAN_DRV_NAME	"rcar_can"
+
+/* Mailbox configuration:
+ * mailbox 60 - 63 - Rx FIFO mailboxes
+ * mailbox 56 - 59 - Tx FIFO mailboxes
+ * non-FIFO mailboxes are not used
+ */
+#define RCAR_CAN_N_MBX		64 /* Number of mailboxes in non-FIFO mode */
+#define RCAR_CAN_RX_FIFO_MBX	60 /* Mailbox - window to Rx FIFO */
+#define RCAR_CAN_TX_FIFO_MBX	56 /* Mailbox - window to Tx FIFO */
+#define RCAR_CAN_FIFO_DEPTH	4
+
+/* Mailbox registers structure */
+struct rcar_can_mbox_regs {
+	u32 id;		/* IDE and RTR bits, SID and EID */
+	u8 stub;	/* Not used */
+	u8 dlc;		/* Data Length Code - bits [0..3] */
+	u8 data[8];	/* Data Bytes */
+	u8 tsh;		/* Time Stamp Higher Byte */
+	u8 tsl;		/* Time Stamp Lower Byte */
+};
+
+struct rcar_can_regs {
+	struct rcar_can_mbox_regs mb[RCAR_CAN_N_MBX]; /* Mailbox registers */
+	u32 mkr_2_9[8];	/* Mask Registers 2-9 */
+	u32 fidcr[2];	/* FIFO Received ID Compare Register */
+	u32 mkivlr1;	/* Mask Invalid Register 1 */
+	u32 mier1;	/* Mailbox Interrupt Enable Register 1 */
+	u32 mkr_0_1[2];	/* Mask Registers 0-1 */
+	u32 mkivlr0;    /* Mask Invalid Register 0*/
+	u32 mier0;      /* Mailbox Interrupt Enable Register 0 */
+	u8 pad_440[0x3c0];
+	u8 mctl[64];	/* Message Control Registers */
+	u16 ctlr;	/* Control Register */
+	u16 str;	/* Status register */
+	u8 bcr[3];	/* Bit Configuration Register */
+	u8 clkr;	/* Clock Select Register */
+	u8 rfcr;	/* Receive FIFO Control Register */
+	u8 rfpcr;	/* Receive FIFO Pointer Control Register */
+	u8 tfcr;	/* Transmit FIFO Control Register */
+	u8 tfpcr;       /* Transmit FIFO Pointer Control Register */
+	u8 eier;	/* Error Interrupt Enable Register */
+	u8 eifr;	/* Error Interrupt Factor Judge Register */
+	u8 recr;	/* Receive Error Count Register */
+	u8 tecr;        /* Transmit Error Count Register */
+	u8 ecsr;	/* Error Code Store Register */
+	u8 cssr;	/* Channel Search Support Register */
+	u8 mssr;	/* Mailbox Search Status Register */
+	u8 msmr;	/* Mailbox Search Mode Register */
+	u16 tsr;	/* Time Stamp Register */
+	u8 afsr;	/* Acceptance Filter Support Register */
+	u8 pad_857;
+	u8 tcr;		/* Test Control Register */
+	u8 pad_859[7];
+	u8 ier;		/* Interrupt Enable Register */
+	u8 isr;		/* Interrupt Status Register */
+	u8 pad_862;
+	u8 mbsmr;	/* Mailbox Search Mask Register */
+};
+
+struct rcar_can_priv {
+	struct can_priv can;	/* Must be the first member! */
+	struct net_device *ndev;
+	struct napi_struct napi;
+	struct rcar_can_regs __iomem *regs;
+	struct clk *clk;
+	u8 tx_dlc[RCAR_CAN_FIFO_DEPTH];
+	u32 tx_head;
+	u32 tx_tail;
+	u8 clock_select;
+	u8 ier;
+};
+
+static const struct can_bittiming_const rcar_can_bittiming_const = {
+	.name = RCAR_CAN_DRV_NAME,
+	.tseg1_min = 4,
+	.tseg1_max = 16,
+	.tseg2_min = 2,
+	.tseg2_max = 8,
+	.sjw_max = 4,
+	.brp_min = 1,
+	.brp_max = 1024,
+	.brp_inc = 1,
+};
+
+/* Control Register bits */
+#define RCAR_CAN_CTLR_BOM	(3 << 11) /* Bus-Off Recovery Mode Bits */
+#define RCAR_CAN_CTLR_BOM_ENT	(1 << 11) /* Entry to halt mode */
+					/* at bus-off entry */
+#define RCAR_CAN_CTLR_SLPM	(1 << 10)
+#define RCAR_CAN_CTLR_CANM	(3 << 8) /* Operating Mode Select Bit */
+#define RCAR_CAN_CTLR_CANM_HALT	(1 << 9)
+#define RCAR_CAN_CTLR_CANM_RESET (1 << 8)
+#define RCAR_CAN_CTLR_CANM_FORCE_RESET (3 << 8)
+#define RCAR_CAN_CTLR_MLM	(1 << 3) /* Message Lost Mode Select */
+#define RCAR_CAN_CTLR_IDFM	(3 << 1) /* ID Format Mode Select Bits */
+#define RCAR_CAN_CTLR_IDFM_MIXED (1 << 2) /* Mixed ID mode */
+#define RCAR_CAN_CTLR_MBM	(1 << 0) /* Mailbox Mode select */
+
+/* Status Register bits */
+#define RCAR_CAN_STR_RSTST	(1 << 8) /* Reset Status Bit */
+
+/* FIFO Received ID Compare Registers 0 and 1 bits */
+#define RCAR_CAN_FIDCR_IDE	(1 << 31) /* ID Extension Bit */
+#define RCAR_CAN_FIDCR_RTR	(1 << 30) /* Remote Transmission Request Bit */
+
+/* Receive FIFO Control Register bits */
+#define RCAR_CAN_RFCR_RFEST	(1 << 7) /* Receive FIFO Empty Status Flag */
+#define RCAR_CAN_RFCR_RFE	(1 << 0) /* Receive FIFO Enable */
+
+/* Transmit FIFO Control Register bits */
+#define RCAR_CAN_TFCR_TFUST	(7 << 1) /* Transmit FIFO Unsent Message */
+					/* Number Status Bits */
+#define RCAR_CAN_TFCR_TFUST_SHIFT 1	/* Offset of Transmit FIFO Unsent */
+					/* Message Number Status Bits */
+#define RCAR_CAN_TFCR_TFE	(1 << 0) /* Transmit FIFO Enable */
+
+#define RCAR_CAN_N_RX_MKREGS1	2	/* Number of mask registers */
+					/* for Rx mailboxes 0-31 */
+#define RCAR_CAN_N_RX_MKREGS2	8
+
+/* Bit Configuration Register settings */
+#define RCAR_CAN_BCR_TSEG1(x)	(((x) & 0x0f) << 20)
+#define RCAR_CAN_BCR_BPR(x)	(((x) & 0x3ff) << 8)
+#define RCAR_CAN_BCR_SJW(x)	(((x) & 0x3) << 4)
+#define RCAR_CAN_BCR_TSEG2(x)	((x) & 0x07)
+
+/* Mailbox and Mask Registers bits */
+#define RCAR_CAN_IDE		(1 << 31)
+#define RCAR_CAN_RTR		(1 << 30)
+#define RCAR_CAN_SID_SHIFT	18
+
+/* Mailbox Interrupt Enable Register 1 bits */
+#define RCAR_CAN_MIER1_RXFIE	(1 << 28) /* Receive  FIFO Interrupt Enable */
+#define RCAR_CAN_MIER1_TXFIE	(1 << 24) /* Transmit FIFO Interrupt Enable */
+
+/* Interrupt Enable Register bits */
+#define RCAR_CAN_IER_ERSIE	(1 << 5) /* Error (ERS) Interrupt Enable Bit */
+#define RCAR_CAN_IER_RXFIE	(1 << 4) /* Reception FIFO Interrupt */
+					/* Enable Bit */
+#define RCAR_CAN_IER_TXFIE	(1 << 3) /* Transmission FIFO Interrupt */
+					/* Enable Bit */
+/* Interrupt Status Register bits */
+#define RCAR_CAN_ISR_ERSF	(1 << 5) /* Error (ERS) Interrupt Status Bit */
+#define RCAR_CAN_ISR_RXFF	(1 << 4) /* Reception FIFO Interrupt */
+					/* Status Bit */
+#define RCAR_CAN_ISR_TXFF	(1 << 3) /* Transmission FIFO Interrupt */
+					/* Status Bit */
+
+/* Error Interrupt Enable Register bits */
+#define RCAR_CAN_EIER_BLIE	(1 << 7) /* Bus Lock Interrupt Enable */
+#define RCAR_CAN_EIER_OLIE	(1 << 6) /* Overload Frame Transmit */
+					/* Interrupt Enable */
+#define RCAR_CAN_EIER_ORIE	(1 << 5) /* Receive Overrun  Interrupt Enable */
+#define RCAR_CAN_EIER_BORIE	(1 << 4) /* Bus-Off Recovery Interrupt Enable */
+#define RCAR_CAN_EIER_BOEIE	(1 << 3) /* Bus-Off Entry Interrupt Enable */
+#define RCAR_CAN_EIER_EPIE	(1 << 2) /* Error Passive Interrupt Enable */
+#define RCAR_CAN_EIER_EWIE	(1 << 1) /* Error Warning Interrupt Enable */
+#define RCAR_CAN_EIER_BEIE	(1 << 0) /* Bus Error Interrupt Enable */
+
+/* Error Interrupt Factor Judge Register bits */
+#define RCAR_CAN_EIFR_BLIF	(1 << 7) /* Bus Lock Detect Flag */
+#define RCAR_CAN_EIFR_OLIF	(1 << 6) /* Overload Frame Transmission */
+					 /* Detect Flag */
+#define RCAR_CAN_EIFR_ORIF	(1 << 5) /* Receive Overrun Detect Flag */
+#define RCAR_CAN_EIFR_BORIF	(1 << 4) /* Bus-Off Recovery Detect Flag */
+#define RCAR_CAN_EIFR_BOEIF	(1 << 3) /* Bus-Off Entry Detect Flag */
+#define RCAR_CAN_EIFR_EPIF	(1 << 2) /* Error Passive Detect Flag */
+#define RCAR_CAN_EIFR_EWIF	(1 << 1) /* Error Warning Detect Flag */
+#define RCAR_CAN_EIFR_BEIF	(1 << 0) /* Bus Error Detect Flag */
+
+/* Error Code Store Register bits */
+#define RCAR_CAN_ECSR_EDPM	(1 << 7) /* Error Display Mode Select Bit */
+#define RCAR_CAN_ECSR_ADEF	(1 << 6) /* ACK Delimiter Error Flag */
+#define RCAR_CAN_ECSR_BE0F	(1 << 5) /* Bit Error (dominant) Flag */
+#define RCAR_CAN_ECSR_BE1F	(1 << 4) /* Bit Error (recessive) Flag */
+#define RCAR_CAN_ECSR_CEF	(1 << 3) /* CRC Error Flag */
+#define RCAR_CAN_ECSR_AEF	(1 << 2) /* ACK Error Flag */
+#define RCAR_CAN_ECSR_FEF	(1 << 1) /* Form Error Flag */
+#define RCAR_CAN_ECSR_SEF	(1 << 0) /* Stuff Error Flag */
+
+#define RCAR_CAN_NAPI_WEIGHT	4
+#define MAX_STR_READS		0x100
+
+static void tx_failure_cleanup(struct net_device *ndev)
+{
+	int i;
+
+	for (i = 0; i < RCAR_CAN_FIFO_DEPTH; i++)
+		can_free_echo_skb(ndev, i);
+}
+
+static void rcar_can_error(struct net_device *ndev)
+{
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &ndev->stats;
+	struct can_frame *cf;
+	struct sk_buff *skb;
+	u8 eifr, txerr = 0, rxerr = 0;
+
+	/* Propagate the error condition to the CAN stack */
+	skb = alloc_can_err_skb(ndev, &cf);
+
+	eifr = readb(&priv->regs->eifr);
+	if (eifr & (RCAR_CAN_EIFR_EWIF | RCAR_CAN_EIFR_EPIF)) {
+		txerr = readb(&priv->regs->tecr);
+		rxerr = readb(&priv->regs->recr);
+		if (skb) {
+			cf->can_id |= CAN_ERR_CRTL;
+			cf->data[6] = txerr;
+			cf->data[7] = rxerr;
+		}
+	}
+	if (eifr & RCAR_CAN_EIFR_BEIF) {
+		int rx_errors = 0, tx_errors = 0;
+		u8 ecsr;
+
+		netdev_dbg(priv->ndev, "Bus error interrupt:\n");
+		if (skb) {
+			cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
+			cf->data[2] = CAN_ERR_PROT_UNSPEC;
+		}
+		ecsr = readb(&priv->regs->ecsr);
+		if (ecsr & RCAR_CAN_ECSR_ADEF) {
+			netdev_dbg(priv->ndev, "ACK Delimiter Error\n");
+			tx_errors++;
+			writeb(~RCAR_CAN_ECSR_ADEF, &priv->regs->ecsr);
+			if (skb)
+				cf->data[3] |= CAN_ERR_PROT_LOC_ACK_DEL;
+		}
+		if (ecsr & RCAR_CAN_ECSR_BE0F) {
+			netdev_dbg(priv->ndev, "Bit Error (dominant)\n");
+			tx_errors++;
+			writeb(~RCAR_CAN_ECSR_BE0F, &priv->regs->ecsr);
+			if (skb)
+				cf->data[2] |= CAN_ERR_PROT_BIT0;
+		}
+		if (ecsr & RCAR_CAN_ECSR_BE1F) {
+			netdev_dbg(priv->ndev, "Bit Error (recessive)\n");
+			tx_errors++;
+			writeb(~RCAR_CAN_ECSR_BE1F, &priv->regs->ecsr);
+			if (skb)
+				cf->data[2] |= CAN_ERR_PROT_BIT1;
+		}
+		if (ecsr & RCAR_CAN_ECSR_CEF) {
+			netdev_dbg(priv->ndev, "CRC Error\n");
+			rx_errors++;
+			writeb(~RCAR_CAN_ECSR_CEF, &priv->regs->ecsr);
+			if (skb)
+				cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+		}
+		if (ecsr & RCAR_CAN_ECSR_AEF) {
+			netdev_dbg(priv->ndev, "ACK Error\n");
+			tx_errors++;
+			writeb(~RCAR_CAN_ECSR_AEF, &priv->regs->ecsr);
+			if (skb) {
+				cf->can_id |= CAN_ERR_ACK;
+				cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
+			}
+		}
+		if (ecsr & RCAR_CAN_ECSR_FEF) {
+			netdev_dbg(priv->ndev, "Form Error\n");
+			rx_errors++;
+			writeb(~RCAR_CAN_ECSR_FEF, &priv->regs->ecsr);
+			if (skb)
+				cf->data[2] |= CAN_ERR_PROT_FORM;
+		}
+		if (ecsr & RCAR_CAN_ECSR_SEF) {
+			netdev_dbg(priv->ndev, "Stuff Error\n");
+			rx_errors++;
+			writeb(~RCAR_CAN_ECSR_SEF, &priv->regs->ecsr);
+			if (skb)
+				cf->data[2] |= CAN_ERR_PROT_STUFF;
+		}
+
+		priv->can.can_stats.bus_error++;
+		ndev->stats.rx_errors += rx_errors;
+		ndev->stats.tx_errors += tx_errors;
+		writeb(~RCAR_CAN_EIFR_BEIF, &priv->regs->eifr);
+	}
+	if (eifr & RCAR_CAN_EIFR_EWIF) {
+		netdev_dbg(priv->ndev, "Error warning interrupt\n");
+		priv->can.state = CAN_STATE_ERROR_WARNING;
+		priv->can.can_stats.error_warning++;
+		/* Clear interrupt condition */
+		writeb(~RCAR_CAN_EIFR_EWIF, &priv->regs->eifr);
+		if (skb)
+			cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_WARNING :
+					      CAN_ERR_CRTL_RX_WARNING;
+	}
+	if (eifr & RCAR_CAN_EIFR_EPIF) {
+		netdev_dbg(priv->ndev, "Error passive interrupt\n");
+		priv->can.state = CAN_STATE_ERROR_PASSIVE;
+		priv->can.can_stats.error_passive++;
+		/* Clear interrupt condition */
+		writeb(~RCAR_CAN_EIFR_EPIF, &priv->regs->eifr);
+		if (skb)
+			cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_PASSIVE :
+					      CAN_ERR_CRTL_RX_PASSIVE;
+	}
+	if (eifr & RCAR_CAN_EIFR_BOEIF) {
+		netdev_dbg(priv->ndev, "Bus-off entry interrupt\n");
+		tx_failure_cleanup(ndev);
+		priv->ier = RCAR_CAN_IER_ERSIE;
+		writeb(priv->ier, &priv->regs->ier);
+		priv->can.state = CAN_STATE_BUS_OFF;
+		/* Clear interrupt condition */
+		writeb(~RCAR_CAN_EIFR_BOEIF, &priv->regs->eifr);
+		can_bus_off(ndev);
+		if (skb)
+			cf->can_id |= CAN_ERR_BUSOFF;
+	}
+	if (eifr & RCAR_CAN_EIFR_ORIF) {
+		netdev_dbg(priv->ndev, "Receive overrun error interrupt\n");
+		ndev->stats.rx_over_errors++;
+		ndev->stats.rx_errors++;
+		writeb(~RCAR_CAN_EIFR_ORIF, &priv->regs->eifr);
+		if (skb) {
+			cf->can_id |= CAN_ERR_CRTL;
+			cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+		}
+	}
+	if (eifr & RCAR_CAN_EIFR_OLIF) {
+		netdev_dbg(priv->ndev,
+			   "Overload Frame Transmission error interrupt\n");
+		ndev->stats.rx_over_errors++;
+		ndev->stats.rx_errors++;
+		writeb(~RCAR_CAN_EIFR_OLIF, &priv->regs->eifr);
+		if (skb) {
+			cf->can_id |= CAN_ERR_PROT;
+			cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
+		}
+	}
+
+	if (skb) {
+		stats->rx_packets++;
+		stats->rx_bytes += cf->can_dlc;
+		netif_rx(skb);
+	}
+}
+
+static void rcar_can_tx_done(struct net_device *ndev)
+{
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &ndev->stats;
+	u8 isr;
+
+	while (1) {
+		u8 unsent = readb(&priv->regs->tfcr);
+
+		unsent = (unsent & RCAR_CAN_TFCR_TFUST) >>
+			  RCAR_CAN_TFCR_TFUST_SHIFT;
+		if (priv->tx_head - priv->tx_tail <= unsent)
+			break;
+		stats->tx_packets++;
+		stats->tx_bytes += priv->tx_dlc[priv->tx_tail %
+						RCAR_CAN_FIFO_DEPTH];
+		priv->tx_dlc[priv->tx_tail % RCAR_CAN_FIFO_DEPTH] = 0;
+		can_get_echo_skb(ndev, priv->tx_tail % RCAR_CAN_FIFO_DEPTH);
+		priv->tx_tail++;
+		netif_wake_queue(ndev);
+	}
+	/* Clear interrupt */
+	isr = readb(&priv->regs->isr);
+	writeb(isr & ~RCAR_CAN_ISR_TXFF, &priv->regs->isr);
+	can_led_event(ndev, CAN_LED_EVENT_TX);
+}
+
+static irqreturn_t rcar_can_interrupt(int irq, void *dev_id)
+{
+	struct net_device *ndev = dev_id;
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+	u8 isr;
+
+	isr = readb(&priv->regs->isr);
+	if (!(isr & priv->ier))
+		return IRQ_NONE;
+
+	if (isr & RCAR_CAN_ISR_ERSF)
+		rcar_can_error(ndev);
+
+	if (isr & RCAR_CAN_ISR_TXFF)
+		rcar_can_tx_done(ndev);
+
+	if (isr & RCAR_CAN_ISR_RXFF) {
+		if (napi_schedule_prep(&priv->napi)) {
+			/* Disable Rx FIFO interrupts */
+			priv->ier &= ~RCAR_CAN_IER_RXFIE;
+			writeb(priv->ier, &priv->regs->ier);
+			__napi_schedule(&priv->napi);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void rcar_can_set_bittiming(struct net_device *dev)
+{
+	struct rcar_can_priv *priv = netdev_priv(dev);
+	struct can_bittiming *bt = &priv->can.bittiming;
+	u32 bcr;
+
+	bcr = RCAR_CAN_BCR_TSEG1(bt->phase_seg1 + bt->prop_seg - 1) |
+	      RCAR_CAN_BCR_BPR(bt->brp - 1) | RCAR_CAN_BCR_SJW(bt->sjw - 1) |
+	      RCAR_CAN_BCR_TSEG2(bt->phase_seg2 - 1);
+	/* Don't overwrite CLKR with 32-bit BCR access; CLKR has 8-bit access.
+	 * All the registers are big-endian but they get byte-swapped on 32-bit
+	 * read/write (but not on 8-bit, contrary to the manuals)...
+	 */
+	writel((bcr << 8) | priv->clock_select, &priv->regs->bcr);
+}
+
+static void rcar_can_start(struct net_device *ndev)
+{
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+	u16 ctlr;
+	int i;
+
+	/* Set controller to known mode:
+	 * - FIFO mailbox mode
+	 * - accept all messages
+	 * - overrun mode
+	 * CAN is in sleep mode after MCU hardware or software reset.
+	 */
+	ctlr = readw(&priv->regs->ctlr);
+	ctlr &= ~RCAR_CAN_CTLR_SLPM;
+	writew(ctlr, &priv->regs->ctlr);
+	/* Go to reset mode */
+	ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
+	writew(ctlr, &priv->regs->ctlr);
+	for (i = 0; i < MAX_STR_READS; i++) {
+		if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
+			break;
+	}
+	rcar_can_set_bittiming(ndev);
+	ctlr |= RCAR_CAN_CTLR_IDFM_MIXED; /* Select mixed ID mode */
+	ctlr |= RCAR_CAN_CTLR_BOM_ENT;	/* Entry to halt mode automatically */
+					/* at bus-off */
+	ctlr |= RCAR_CAN_CTLR_MBM;	/* Select FIFO mailbox mode */
+	ctlr |= RCAR_CAN_CTLR_MLM;	/* Overrun mode */
+	writew(ctlr, &priv->regs->ctlr);
+
+	/* Accept all SID and EID */
+	writel(0, &priv->regs->mkr_2_9[6]);
+	writel(0, &priv->regs->mkr_2_9[7]);
+	/* In FIFO mailbox mode, write "0" to bits 24 to 31 */
+	writel(0, &priv->regs->mkivlr1);
+	/* Accept all frames */
+	writel(0, &priv->regs->fidcr[0]);
+	writel(RCAR_CAN_FIDCR_IDE | RCAR_CAN_FIDCR_RTR, &priv->regs->fidcr[1]);
+	/* Enable and configure FIFO mailbox interrupts */
+	writel(RCAR_CAN_MIER1_RXFIE | RCAR_CAN_MIER1_TXFIE, &priv->regs->mier1);
+
+	priv->ier = RCAR_CAN_IER_ERSIE | RCAR_CAN_IER_RXFIE |
+		    RCAR_CAN_IER_TXFIE;
+	writeb(priv->ier, &priv->regs->ier);
+
+	/* Accumulate error codes */
+	writeb(RCAR_CAN_ECSR_EDPM, &priv->regs->ecsr);
+	/* Enable error interrupts */
+	writeb(RCAR_CAN_EIER_EWIE | RCAR_CAN_EIER_EPIE | RCAR_CAN_EIER_BOEIE |
+	       (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING ?
+	       RCAR_CAN_EIER_BEIE : 0) | RCAR_CAN_EIER_ORIE |
+	       RCAR_CAN_EIER_OLIE, &priv->regs->eier);
+	priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+	/* Go to operation mode */
+	writew(ctlr & ~RCAR_CAN_CTLR_CANM, &priv->regs->ctlr);
+	for (i = 0; i < MAX_STR_READS; i++) {
+		if (!(readw(&priv->regs->str) & RCAR_CAN_STR_RSTST))
+			break;
+	}
+	/* Enable Rx and Tx FIFO */
+	writeb(RCAR_CAN_RFCR_RFE, &priv->regs->rfcr);
+	writeb(RCAR_CAN_TFCR_TFE, &priv->regs->tfcr);
+}
+
+static int rcar_can_open(struct net_device *ndev)
+{
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+	int err;
+
+	err = clk_prepare_enable(priv->clk);
+	if (err) {
+		netdev_err(ndev, "clk_prepare_enable() failed, error %d\n",
+			   err);
+		goto out;
+	}
+	err = open_candev(ndev);
+	if (err) {
+		netdev_err(ndev, "open_candev() failed, error %d\n", err);
+		goto out_clock;
+	}
+	napi_enable(&priv->napi);
+	err = request_irq(ndev->irq, rcar_can_interrupt, 0, ndev->name, ndev);
+	if (err) {
+		netdev_err(ndev, "error requesting interrupt %x\n", ndev->irq);
+		goto out_close;
+	}
+	can_led_event(ndev, CAN_LED_EVENT_OPEN);
+	rcar_can_start(ndev);
+	netif_start_queue(ndev);
+	return 0;
+out_close:
+	napi_disable(&priv->napi);
+	close_candev(ndev);
+out_clock:
+	clk_disable_unprepare(priv->clk);
+out:
+	return err;
+}
+
+static void rcar_can_stop(struct net_device *ndev)
+{
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+	u16 ctlr;
+	int i;
+
+	/* Go to (force) reset mode */
+	ctlr = readw(&priv->regs->ctlr);
+	ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
+	writew(ctlr, &priv->regs->ctlr);
+	for (i = 0; i < MAX_STR_READS; i++) {
+		if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
+			break;
+	}
+	writel(0, &priv->regs->mier0);
+	writel(0, &priv->regs->mier1);
+	writeb(0, &priv->regs->ier);
+	writeb(0, &priv->regs->eier);
+	/* Go to sleep mode */
+	ctlr |= RCAR_CAN_CTLR_SLPM;
+	writew(ctlr, &priv->regs->ctlr);
+	priv->can.state = CAN_STATE_STOPPED;
+}
+
+static int rcar_can_close(struct net_device *ndev)
+{
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+
+	netif_stop_queue(ndev);
+	rcar_can_stop(ndev);
+	free_irq(ndev->irq, ndev);
+	napi_disable(&priv->napi);
+	clk_disable_unprepare(priv->clk);
+	close_candev(ndev);
+	can_led_event(ndev, CAN_LED_EVENT_STOP);
+	return 0;
+}
+
+static netdev_tx_t rcar_can_start_xmit(struct sk_buff *skb,
+				       struct net_device *ndev)
+{
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+	struct can_frame *cf = (struct can_frame *)skb->data;
+	u32 data, i;
+
+	if (can_dropped_invalid_skb(ndev, skb))
+		return NETDEV_TX_OK;
+
+	if (cf->can_id & CAN_EFF_FLAG)	/* Extended frame format */
+		data = (cf->can_id & CAN_EFF_MASK) | RCAR_CAN_IDE;
+	else				/* Standard frame format */
+		data = (cf->can_id & CAN_SFF_MASK) << RCAR_CAN_SID_SHIFT;
+
+	if (cf->can_id & CAN_RTR_FLAG) { /* Remote transmission request */
+		data |= RCAR_CAN_RTR;
+	} else {
+		for (i = 0; i < cf->can_dlc; i++)
+			writeb(cf->data[i],
+			       &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].data[i]);
+	}
+
+	writel(data, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].id);
+
+	writeb(cf->can_dlc, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].dlc);
+
+	priv->tx_dlc[priv->tx_head % RCAR_CAN_FIFO_DEPTH] = cf->can_dlc;
+	can_put_echo_skb(skb, ndev, priv->tx_head % RCAR_CAN_FIFO_DEPTH);
+	priv->tx_head++;
+	/* Start Tx: write 0xff to the TFPCR register to increment
+	 * the CPU-side pointer for the transmit FIFO to the next
+	 * mailbox location
+	 */
+	writeb(0xff, &priv->regs->tfpcr);
+	/* Stop the queue if we've filled all FIFO entries */
+	if (priv->tx_head - priv->tx_tail >= RCAR_CAN_FIFO_DEPTH)
+		netif_stop_queue(ndev);
+
+	return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops rcar_can_netdev_ops = {
+	.ndo_open = rcar_can_open,
+	.ndo_stop = rcar_can_close,
+	.ndo_start_xmit = rcar_can_start_xmit,
+};
+
+static void rcar_can_rx_pkt(struct rcar_can_priv *priv)
+{
+	struct net_device_stats *stats = &priv->ndev->stats;
+	struct can_frame *cf;
+	struct sk_buff *skb;
+	u32 data;
+	u8 dlc;
+
+	skb = alloc_can_skb(priv->ndev, &cf);
+	if (!skb) {
+		stats->rx_dropped++;
+		return;
+	}
+
+	data = readl(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].id);
+	if (data & RCAR_CAN_IDE)
+		cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
+	else
+		cf->can_id = (data >> RCAR_CAN_SID_SHIFT) & CAN_SFF_MASK;
+
+	dlc = readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].dlc);
+	cf->can_dlc = get_can_dlc(dlc);
+	if (data & RCAR_CAN_RTR) {
+		cf->can_id |= CAN_RTR_FLAG;
+	} else {
+		for (dlc = 0; dlc < cf->can_dlc; dlc++)
+			cf->data[dlc] =
+			readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].data[dlc]);
+	}
+
+	can_led_event(priv->ndev, CAN_LED_EVENT_RX);
+
+	stats->rx_bytes += cf->can_dlc;
+	stats->rx_packets++;
+	netif_receive_skb(skb);
+}
+
+static int rcar_can_rx_poll(struct napi_struct *napi, int quota)
+{
+	struct rcar_can_priv *priv = container_of(napi,
+						  struct rcar_can_priv, napi);
+	int num_pkts;
+
+	for (num_pkts = 0; num_pkts < quota; num_pkts++) {
+		u8 rfcr, isr;
+
+		isr = readb(&priv->regs->isr);
+		/* Clear interrupt bit */
+		if (isr & RCAR_CAN_ISR_RXFF)
+			writeb(isr & ~RCAR_CAN_ISR_RXFF, &priv->regs->isr);
+		rfcr = readb(&priv->regs->rfcr);
+		if (rfcr & RCAR_CAN_RFCR_RFEST)
+			break;
+		rcar_can_rx_pkt(priv);
+		/* Write 0xff to the RFPCR register to increment
+		 * the CPU-side pointer for the receive FIFO
+		 * to the next mailbox location
+		 */
+		writeb(0xff, &priv->regs->rfpcr);
+	}
+	/* All packets processed */
+	if (num_pkts < quota) {
+		napi_complete(napi);
+		priv->ier |= RCAR_CAN_IER_RXFIE;
+		writeb(priv->ier, &priv->regs->ier);
+	}
+	return num_pkts;
+}
+
+static int rcar_can_do_set_mode(struct net_device *ndev, enum can_mode mode)
+{
+	switch (mode) {
+	case CAN_MODE_START:
+		rcar_can_start(ndev);
+		netif_wake_queue(ndev);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int rcar_can_get_berr_counter(const struct net_device *dev,
+				     struct can_berr_counter *bec)
+{
+	struct rcar_can_priv *priv = netdev_priv(dev);
+	int err;
+
+	err = clk_prepare_enable(priv->clk);
+	if (err)
+		return err;
+	bec->txerr = readb(&priv->regs->tecr);
+	bec->rxerr = readb(&priv->regs->recr);
+	clk_disable_unprepare(priv->clk);
+	return 0;
+}
+
+static int rcar_can_probe(struct platform_device *pdev)
+{
+	struct rcar_can_platform_data *pdata;
+	struct rcar_can_priv *priv;
+	struct net_device *ndev;
+	struct resource *mem;
+	void __iomem *addr;
+	int err = -ENODEV;
+	int irq;
+
+	pdata = dev_get_platdata(&pdev->dev);
+	if (!pdata) {
+		dev_err(&pdev->dev, "No platform data provided!\n");
+		goto fail;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (!irq) {
+		dev_err(&pdev->dev, "No IRQ resource\n");
+		goto fail;
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	addr = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(addr)) {
+		err = PTR_ERR(addr);
+		goto fail;
+	}
+
+	ndev = alloc_candev(sizeof(struct rcar_can_priv), RCAR_CAN_FIFO_DEPTH);
+	if (!ndev) {
+		dev_err(&pdev->dev, "alloc_candev() failed\n");
+		err = -ENOMEM;
+		goto fail;
+	}
+
+	priv = netdev_priv(ndev);
+
+	priv->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		err = PTR_ERR(priv->clk);
+		dev_err(&pdev->dev, "cannot get clock: %d\n", err);
+		goto fail_clk;
+	}
+
+	ndev->netdev_ops = &rcar_can_netdev_ops;
+	ndev->irq = irq;
+	ndev->flags |= IFF_ECHO;
+	priv->ndev = ndev;
+	priv->regs = addr;
+	priv->clock_select = pdata->clock_select;
+	priv->can.clock.freq = clk_get_rate(priv->clk);
+	priv->can.bittiming_const = &rcar_can_bittiming_const;
+	priv->can.do_set_mode = rcar_can_do_set_mode;
+	priv->can.do_get_berr_counter = rcar_can_get_berr_counter;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING;
+	platform_set_drvdata(pdev, ndev);
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+
+	netif_napi_add(ndev, &priv->napi, rcar_can_rx_poll,
+		       RCAR_CAN_NAPI_WEIGHT);
+	err = register_candev(ndev);
+	if (err) {
+		dev_err(&pdev->dev, "register_candev() failed, error %d\n",
+			err);
+		goto fail_candev;
+	}
+
+	devm_can_led_init(ndev);
+
+	dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
+		 priv->regs, ndev->irq);
+
+	return 0;
+fail_candev:
+	netif_napi_del(&priv->napi);
+fail_clk:
+	free_candev(ndev);
+fail:
+	return err;
+}
+
+static int rcar_can_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+
+	unregister_candev(ndev);
+	netif_napi_del(&priv->napi);
+	free_candev(ndev);
+	return 0;
+}
+
+static int __maybe_unused rcar_can_suspend(struct device *dev)
+{
+	struct net_device *ndev = dev_get_drvdata(dev);
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+	u16 ctlr;
+
+	if (netif_running(ndev)) {
+		netif_stop_queue(ndev);
+		netif_device_detach(ndev);
+	}
+	ctlr = readw(&priv->regs->ctlr);
+	ctlr |= RCAR_CAN_CTLR_CANM_HALT;
+	writew(ctlr, &priv->regs->ctlr);
+	ctlr |= RCAR_CAN_CTLR_SLPM;
+	writew(ctlr, &priv->regs->ctlr);
+	priv->can.state = CAN_STATE_SLEEPING;
+
+	clk_disable(priv->clk);
+	return 0;
+}
+
+static int __maybe_unused rcar_can_resume(struct device *dev)
+{
+	struct net_device *ndev = dev_get_drvdata(dev);
+	struct rcar_can_priv *priv = netdev_priv(ndev);
+	u16 ctlr;
+	int err;
+
+	err = clk_enable(priv->clk);
+	if (err) {
+		netdev_err(ndev, "clk_enable() failed, error %d\n", err);
+		return err;
+	}
+
+	ctlr = readw(&priv->regs->ctlr);
+	ctlr &= ~RCAR_CAN_CTLR_SLPM;
+	writew(ctlr, &priv->regs->ctlr);
+	ctlr &= ~RCAR_CAN_CTLR_CANM;
+	writew(ctlr, &priv->regs->ctlr);
+	priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+	if (netif_running(ndev)) {
+		netif_device_attach(ndev);
+		netif_start_queue(ndev);
+	}
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(rcar_can_pm_ops, rcar_can_suspend, rcar_can_resume);
+
+static struct platform_driver rcar_can_driver = {
+	.driver = {
+		.name = RCAR_CAN_DRV_NAME,
+		.owner = THIS_MODULE,
+		.pm = &rcar_can_pm_ops,
+	},
+	.probe = rcar_can_probe,
+	.remove = rcar_can_remove,
+};
+
+module_platform_driver(rcar_can_driver);
+
+MODULE_AUTHOR("Cogent Embedded, Inc.");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CAN driver for Renesas R-Car SoC");
+MODULE_ALIAS("platform:" RCAR_CAN_DRV_NAME);
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index bc235f9dc754..5df239e68812 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -951,7 +951,7 @@ static int mcp251x_open(struct net_device *net)
 	priv->tx_len = 0;
 
 	ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,
-				   flags, DEVICE_NAME, priv);
+				   flags | IRQF_ONESHOT, DEVICE_NAME, priv);
 	if (ret) {
 		dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
 		mcp251x_power_enable(priv->transceiver, 0);
diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
index 0b918ebad76b..a77db919363c 100644
--- a/drivers/net/can/usb/Kconfig
+++ b/drivers/net/can/usb/Kconfig
@@ -13,6 +13,14 @@ config CAN_ESD_USB2
           This driver supports the CAN-USB/2 interface
           from esd electronic system design gmbh (http://www.esd.eu).
 
+config CAN_GS_USB
+	tristate "Geschwister Schneider UG interfaces"
+	---help---
+	  This driver supports the Geschwister Schneider USB/CAN devices.
+	  If unsure choose N,
+	  choose Y for built in support,
+	  M to compile as module (module will be named: gs_usb).
+
 config CAN_KVASER_USB
 	tristate "Kvaser CAN/USB interface"
 	---help---
diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
index becef460a91a..7b9a393b1ac8 100644
--- a/drivers/net/can/usb/Makefile
+++ b/drivers/net/can/usb/Makefile
@@ -4,6 +4,7 @@
 
 obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
 obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
+obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
 obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
 obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
 obj-$(CONFIG_CAN_8DEV_USB) += usb_8dev.o
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
new file mode 100644
index 000000000000..c9f1f99682b1
--- /dev/null
+++ b/drivers/net/can/usb/gs_usb.c
@@ -0,0 +1,971 @@
+/* CAN driver for Geschwister Schneider USB/CAN devices.
+ *
+ * Copyright (C) 2013 Geschwister Schneider Technologie-,
+ * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
+ *
+ * Many thanks to all socketcan devs!
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/signal.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/usb.h>
+
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/error.h>
+
+/* Device specific constants */
+#define USB_GSUSB_1_VENDOR_ID      0x1d50
+#define USB_GSUSB_1_PRODUCT_ID     0x606f
+
+#define GSUSB_ENDPOINT_IN          1
+#define GSUSB_ENDPOINT_OUT         2
+
+/* Device specific constants */
+enum gs_usb_breq {
+	GS_USB_BREQ_HOST_FORMAT = 0,
+	GS_USB_BREQ_BITTIMING,
+	GS_USB_BREQ_MODE,
+	GS_USB_BREQ_BERR,
+	GS_USB_BREQ_BT_CONST,
+	GS_USB_BREQ_DEVICE_CONFIG
+};
+
+enum gs_can_mode {
+	/* reset a channel. turns it off */
+	GS_CAN_MODE_RESET = 0,
+	/* starts a channel */
+	GS_CAN_MODE_START
+};
+
+enum gs_can_state {
+	GS_CAN_STATE_ERROR_ACTIVE = 0,
+	GS_CAN_STATE_ERROR_WARNING,
+	GS_CAN_STATE_ERROR_PASSIVE,
+	GS_CAN_STATE_BUS_OFF,
+	GS_CAN_STATE_STOPPED,
+	GS_CAN_STATE_SLEEPING
+};
+
+/* data types passed between host and device */
+struct gs_host_config {
+	u32 byte_order;
+} __packed;
+/* All data exchanged between host and device is exchanged in host byte order,
+ * thanks to the struct gs_host_config byte_order member, which is sent first
+ * to indicate the desired byte order.
+ */
+
+struct gs_device_config {
+	u8 reserved1;
+	u8 reserved2;
+	u8 reserved3;
+	u8 icount;
+	u32 sw_version;
+	u32 hw_version;
+} __packed;
+
+#define GS_CAN_MODE_NORMAL               0
+#define GS_CAN_MODE_LISTEN_ONLY          (1<<0)
+#define GS_CAN_MODE_LOOP_BACK            (1<<1)
+#define GS_CAN_MODE_TRIPLE_SAMPLE        (1<<2)
+#define GS_CAN_MODE_ONE_SHOT             (1<<3)
+
+struct gs_device_mode {
+	u32 mode;
+	u32 flags;
+} __packed;
+
+struct gs_device_state {
+	u32 state;
+	u32 rxerr;
+	u32 txerr;
+} __packed;
+
+struct gs_device_bittiming {
+	u32 prop_seg;
+	u32 phase_seg1;
+	u32 phase_seg2;
+	u32 sjw;
+	u32 brp;
+} __packed;
+
+#define GS_CAN_FEATURE_LISTEN_ONLY      (1<<0)
+#define GS_CAN_FEATURE_LOOP_BACK        (1<<1)
+#define GS_CAN_FEATURE_TRIPLE_SAMPLE    (1<<2)
+#define GS_CAN_FEATURE_ONE_SHOT         (1<<3)
+
+struct gs_device_bt_const {
+	u32 feature;
+	u32 fclk_can;
+	u32 tseg1_min;
+	u32 tseg1_max;
+	u32 tseg2_min;
+	u32 tseg2_max;
+	u32 sjw_max;
+	u32 brp_min;
+	u32 brp_max;
+	u32 brp_inc;
+} __packed;
+
+#define GS_CAN_FLAG_OVERFLOW 1
+
+struct gs_host_frame {
+	u32 echo_id;
+	u32 can_id;
+
+	u8 can_dlc;
+	u8 channel;
+	u8 flags;
+	u8 reserved;
+
+	u8 data[8];
+} __packed;
+/* The GS USB devices make use of the same flags and masks as in
+ * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
+ */
+
+/* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
+#define GS_MAX_TX_URBS 10
+/* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
+#define GS_MAX_RX_URBS 30
+/* Maximum number of interfaces the driver supports per device.
+ * Current hardware only supports 2 interfaces. The future may vary.
+ */
+#define GS_MAX_INTF 2
+
+struct gs_tx_context {
+	struct gs_can *dev;
+	unsigned int echo_id;
+};
+
+struct gs_can {
+	struct can_priv can; /* must be the first member */
+
+	struct gs_usb *parent;
+
+	struct net_device *netdev;
+	struct usb_device *udev;
+	struct usb_interface *iface;
+
+	struct can_bittiming_const bt_const;
+	unsigned int channel;	/* channel number */
+
+	/* This lock prevents a race condition between xmit and recieve. */
+	spinlock_t tx_ctx_lock;
+	struct gs_tx_context tx_context[GS_MAX_TX_URBS];
+
+	struct usb_anchor tx_submitted;
+	atomic_t active_tx_urbs;
+};
+
+/* usb interface struct */
+struct gs_usb {
+	struct gs_can *canch[GS_MAX_INTF];
+	struct usb_anchor rx_submitted;
+	atomic_t active_channels;
+	struct usb_device *udev;
+};
+
+/* 'allocate' a tx context.
+ * returns a valid tx context or NULL if there is no space.
+ */
+static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
+{
+	int i = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->tx_ctx_lock, flags);
+
+	for (; i < GS_MAX_TX_URBS; i++) {
+		if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
+			dev->tx_context[i].echo_id = i;
+			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
+			return &dev->tx_context[i];
+		}
+	}
+
+	spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
+	return NULL;
+}
+
+/* releases a tx context
+ */
+static void gs_free_tx_context(struct gs_tx_context *txc)
+{
+	txc->echo_id = GS_MAX_TX_URBS;
+}
+
+/* Get a tx context by id.
+ */
+static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev, unsigned int id)
+{
+	unsigned long flags;
+
+	if (id < GS_MAX_TX_URBS) {
+		spin_lock_irqsave(&dev->tx_ctx_lock, flags);
+		if (dev->tx_context[id].echo_id == id) {
+			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
+			return &dev->tx_context[id];
+		}
+		spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
+	}
+	return NULL;
+}
+
+static int gs_cmd_reset(struct gs_usb *gsusb, struct gs_can *gsdev)
+{
+	struct gs_device_mode *dm;
+	struct usb_interface *intf = gsdev->iface;
+	int rc;
+
+	dm = kzalloc(sizeof(*dm), GFP_KERNEL);
+	if (!dm)
+		return -ENOMEM;
+
+	dm->mode = GS_CAN_MODE_RESET;
+
+	rc = usb_control_msg(interface_to_usbdev(intf),
+			     usb_sndctrlpipe(interface_to_usbdev(intf), 0),
+			     GS_USB_BREQ_MODE,
+			     USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+			     gsdev->channel,
+			     0,
+			     dm,
+			     sizeof(*dm),
+			     1000);
+
+	return rc;
+}
+
+static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
+{
+	struct can_device_stats *can_stats = &dev->can.can_stats;
+
+	if (cf->can_id & CAN_ERR_RESTARTED) {
+		dev->can.state = CAN_STATE_ERROR_ACTIVE;
+		can_stats->restarts++;
+	} else if (cf->can_id & CAN_ERR_BUSOFF) {
+		dev->can.state = CAN_STATE_BUS_OFF;
+		can_stats->bus_off++;
+	} else if (cf->can_id & CAN_ERR_CRTL) {
+		if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
+		    (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
+			dev->can.state = CAN_STATE_ERROR_WARNING;
+			can_stats->error_warning++;
+		} else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
+			   (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
+			dev->can.state = CAN_STATE_ERROR_PASSIVE;
+			can_stats->error_passive++;
+		} else {
+			dev->can.state = CAN_STATE_ERROR_ACTIVE;
+		}
+	}
+}
+
+static void gs_usb_recieve_bulk_callback(struct urb *urb)
+{
+	struct gs_usb *usbcan = urb->context;
+	struct gs_can *dev;
+	struct net_device *netdev;
+	int rc;
+	struct net_device_stats *stats;
+	struct gs_host_frame *hf = urb->transfer_buffer;
+	struct gs_tx_context *txc;
+	struct can_frame *cf;
+	struct sk_buff *skb;
+
+	BUG_ON(!usbcan);
+
+	switch (urb->status) {
+	case 0: /* success */
+		break;
+	case -ENOENT:
+	case -ESHUTDOWN:
+		return;
+	default:
+		/* do not resubmit aborted urbs. eg: when device goes down */
+		return;
+	}
+
+	/* device reports out of range channel id */
+	if (hf->channel >= GS_MAX_INTF)
+		goto resubmit_urb;
+
+	dev = usbcan->canch[hf->channel];
+
+	netdev = dev->netdev;
+	stats = &netdev->stats;
+
+	if (!netif_device_present(netdev))
+		return;
+
+	if (hf->echo_id == -1) { /* normal rx */
+		skb = alloc_can_skb(dev->netdev, &cf);
+		if (!skb)
+			return;
+
+		cf->can_id = hf->can_id;
+
+		cf->can_dlc = get_can_dlc(hf->can_dlc);
+		memcpy(cf->data, hf->data, 8);
+
+		/* ERROR frames tell us information about the controller */
+		if (hf->can_id & CAN_ERR_FLAG)
+			gs_update_state(dev, cf);
+
+		netdev->stats.rx_packets++;
+		netdev->stats.rx_bytes += hf->can_dlc;
+
+		netif_rx(skb);
+	} else { /* echo_id == hf->echo_id */
+		if (hf->echo_id >= GS_MAX_TX_URBS) {
+			netdev_err(netdev,
+				   "Unexpected out of range echo id %d\n",
+				   hf->echo_id);
+			goto resubmit_urb;
+		}
+
+		netdev->stats.tx_packets++;
+		netdev->stats.tx_bytes += hf->can_dlc;
+
+		txc = gs_get_tx_context(dev, hf->echo_id);
+
+		/* bad devices send bad echo_ids. */
+		if (!txc) {
+			netdev_err(netdev,
+				   "Unexpected unused echo id %d\n",
+				   hf->echo_id);
+			goto resubmit_urb;
+		}
+
+		can_get_echo_skb(netdev, hf->echo_id);
+
+		gs_free_tx_context(txc);
+
+		netif_wake_queue(netdev);
+	}
+
+	if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
+		skb = alloc_can_err_skb(netdev, &cf);
+		if (!skb)
+			goto resubmit_urb;
+
+		cf->can_id |= CAN_ERR_CRTL;
+		cf->can_dlc = CAN_ERR_DLC;
+		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+		stats->rx_over_errors++;
+		stats->rx_errors++;
+		netif_rx(skb);
+	}
+
+ resubmit_urb:
+	usb_fill_bulk_urb(urb,
+			  usbcan->udev,
+			  usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
+			  hf,
+			  sizeof(struct gs_host_frame),
+			  gs_usb_recieve_bulk_callback,
+			  usbcan
+			  );
+
+	rc = usb_submit_urb(urb, GFP_ATOMIC);
+
+	/* USB failure take down all interfaces */
+	if (rc == -ENODEV) {
+		for (rc = 0; rc < GS_MAX_INTF; rc++) {
+			if (usbcan->canch[rc])
+				netif_device_detach(usbcan->canch[rc]->netdev);
+		}
+	}
+}
+
+static int gs_usb_set_bittiming(struct net_device *netdev)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct can_bittiming *bt = &dev->can.bittiming;
+	struct usb_interface *intf = dev->iface;
+	int rc;
+	struct gs_device_bittiming *dbt;
+
+	dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
+	if (!dbt)
+		return -ENOMEM;
+
+	dbt->prop_seg = bt->prop_seg;
+	dbt->phase_seg1 = bt->phase_seg1;
+	dbt->phase_seg2 = bt->phase_seg2;
+	dbt->sjw = bt->sjw;
+	dbt->brp = bt->brp;
+
+	/* request bit timings */
+	rc = usb_control_msg(interface_to_usbdev(intf),
+			     usb_sndctrlpipe(interface_to_usbdev(intf), 0),
+			     GS_USB_BREQ_BITTIMING,
+			     USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+			     dev->channel,
+			     0,
+			     dbt,
+			     sizeof(*dbt),
+			     1000);
+
+	kfree(dbt);
+
+	if (rc < 0)
+		dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
+			rc);
+
+	return rc;
+}
+
+static void gs_usb_xmit_callback(struct urb *urb)
+{
+	struct gs_tx_context *txc = urb->context;
+	struct gs_can *dev = txc->dev;
+	struct net_device *netdev = dev->netdev;
+
+	if (urb->status)
+		netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
+
+	usb_free_coherent(urb->dev,
+			  urb->transfer_buffer_length,
+			  urb->transfer_buffer,
+			  urb->transfer_dma);
+
+	atomic_dec(&dev->active_tx_urbs);
+
+	if (!netif_device_present(netdev))
+		return;
+
+	if (netif_queue_stopped(netdev))
+		netif_wake_queue(netdev);
+}
+
+static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct net_device_stats *stats = &dev->netdev->stats;
+	struct urb *urb;
+	struct gs_host_frame *hf;
+	struct can_frame *cf;
+	int rc;
+	unsigned int idx;
+	struct gs_tx_context *txc;
+
+	if (can_dropped_invalid_skb(netdev, skb))
+		return NETDEV_TX_OK;
+
+	/* find an empty context to keep track of transmission */
+	txc = gs_alloc_tx_context(dev);
+	if (!txc)
+		return NETDEV_TX_BUSY;
+
+	/* create a URB, and a buffer for it */
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+	if (!urb) {
+		netdev_err(netdev, "No memory left for URB\n");
+		goto nomem_urb;
+	}
+
+	hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
+				&urb->transfer_dma);
+	if (!hf) {
+		netdev_err(netdev, "No memory left for USB buffer\n");
+		goto nomem_hf;
+	}
+
+	idx = txc->echo_id;
+
+	if (idx >= GS_MAX_TX_URBS) {
+		netdev_err(netdev, "Invalid tx context %d\n", idx);
+		goto badidx;
+	}
+
+	hf->echo_id = idx;
+	hf->channel = dev->channel;
+
+	cf = (struct can_frame *)skb->data;
+
+	hf->can_id = cf->can_id;
+	hf->can_dlc = cf->can_dlc;
+	memcpy(hf->data, cf->data, cf->can_dlc);
+
+	usb_fill_bulk_urb(urb, dev->udev,
+			  usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
+			  hf,
+			  sizeof(*hf),
+			  gs_usb_xmit_callback,
+			  txc);
+
+	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	usb_anchor_urb(urb, &dev->tx_submitted);
+
+	can_put_echo_skb(skb, netdev, idx);
+
+	atomic_inc(&dev->active_tx_urbs);
+
+	rc = usb_submit_urb(urb, GFP_ATOMIC);
+	if (unlikely(rc)) {			/* usb send failed */
+		atomic_dec(&dev->active_tx_urbs);
+
+		can_free_echo_skb(netdev, idx);
+		gs_free_tx_context(txc);
+
+		usb_unanchor_urb(urb);
+		usb_free_coherent(dev->udev,
+				  sizeof(*hf),
+				  hf,
+				  urb->transfer_dma);
+
+
+		if (rc == -ENODEV) {
+			netif_device_detach(netdev);
+		} else {
+			netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
+			stats->tx_dropped++;
+		}
+	} else {
+		/* Slow down tx path */
+		if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
+			netif_stop_queue(netdev);
+	}
+
+	/* let usb core take care of this urb */
+	usb_free_urb(urb);
+
+	return NETDEV_TX_OK;
+
+ badidx:
+	usb_free_coherent(dev->udev,
+			  sizeof(*hf),
+			  hf,
+			  urb->transfer_dma);
+ nomem_hf:
+	usb_free_urb(urb);
+
+ nomem_urb:
+	gs_free_tx_context(txc);
+	dev_kfree_skb(skb);
+	stats->tx_dropped++;
+	return NETDEV_TX_OK;
+}
+
+static int gs_can_open(struct net_device *netdev)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct gs_usb *parent = dev->parent;
+	int rc, i;
+	struct gs_device_mode *dm;
+	u32 ctrlmode;
+
+	rc = open_candev(netdev);
+	if (rc)
+		return rc;
+
+	if (atomic_add_return(1, &parent->active_channels) == 1) {
+		for (i = 0; i < GS_MAX_RX_URBS; i++) {
+			struct urb *urb;
+			u8 *buf;
+
+			/* alloc rx urb */
+			urb = usb_alloc_urb(0, GFP_KERNEL);
+			if (!urb) {
+				netdev_err(netdev,
+					   "No memory left for URB\n");
+				return -ENOMEM;
+			}
+
+			/* alloc rx buffer */
+			buf = usb_alloc_coherent(dev->udev,
+						 sizeof(struct gs_host_frame),
+						 GFP_KERNEL,
+						 &urb->transfer_dma);
+			if (!buf) {
+				netdev_err(netdev,
+					   "No memory left for USB buffer\n");
+				usb_free_urb(urb);
+				return -ENOMEM;
+			}
+
+			/* fill, anchor, and submit rx urb */
+			usb_fill_bulk_urb(urb,
+					  dev->udev,
+					  usb_rcvbulkpipe(dev->udev,
+							  GSUSB_ENDPOINT_IN),
+					  buf,
+					  sizeof(struct gs_host_frame),
+					  gs_usb_recieve_bulk_callback,
+					  parent);
+			urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+			usb_anchor_urb(urb, &parent->rx_submitted);
+
+			rc = usb_submit_urb(urb, GFP_KERNEL);
+			if (rc) {
+				if (rc == -ENODEV)
+					netif_device_detach(dev->netdev);
+
+				netdev_err(netdev,
+					   "usb_submit failed (err=%d)\n",
+					   rc);
+
+				usb_unanchor_urb(urb);
+				break;
+			}
+
+			/* Drop reference,
+			 * USB core will take care of freeing it
+			 */
+			usb_free_urb(urb);
+		}
+	}
+
+	dm = kmalloc(sizeof(*dm), GFP_KERNEL);
+	if (!dm)
+		return -ENOMEM;
+
+	/* flags */
+	ctrlmode = dev->can.ctrlmode;
+	dm->flags = 0;
+
+	if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
+		dm->flags |= GS_CAN_MODE_LOOP_BACK;
+	else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
+		dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
+
+	/* Controller is not allowed to retry TX
+	 * this mode is unavailable on atmels uc3c hardware
+	 */
+	if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
+		dm->flags |= GS_CAN_MODE_ONE_SHOT;
+
+	if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
+		dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
+
+	/* finally start device */
+	dm->mode = GS_CAN_MODE_START;
+	rc = usb_control_msg(interface_to_usbdev(dev->iface),
+			     usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
+			     GS_USB_BREQ_MODE,
+			     USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+			     dev->channel,
+			     0,
+			     dm,
+			     sizeof(*dm),
+			     1000);
+
+	if (rc < 0) {
+		netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
+		kfree(dm);
+		return rc;
+	}
+
+	kfree(dm);
+
+	dev->can.state = CAN_STATE_ERROR_ACTIVE;
+
+	if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
+		netif_start_queue(netdev);
+
+	return 0;
+}
+
+static int gs_can_close(struct net_device *netdev)
+{
+	int rc;
+	struct gs_can *dev = netdev_priv(netdev);
+	struct gs_usb *parent = dev->parent;
+
+	netif_stop_queue(netdev);
+
+	/* Stop polling */
+	if (atomic_dec_and_test(&parent->active_channels))
+		usb_kill_anchored_urbs(&parent->rx_submitted);
+
+	/* Stop sending URBs */
+	usb_kill_anchored_urbs(&dev->tx_submitted);
+	atomic_set(&dev->active_tx_urbs, 0);
+
+	/* reset the device */
+	rc = gs_cmd_reset(parent, dev);
+	if (rc < 0)
+		netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
+
+	/* reset tx contexts */
+	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
+		dev->tx_context[rc].dev = dev;
+		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
+	}
+
+	/* close the netdev */
+	close_candev(netdev);
+
+	return 0;
+}
+
+static const struct net_device_ops gs_usb_netdev_ops = {
+	.ndo_open = gs_can_open,
+	.ndo_stop = gs_can_close,
+	.ndo_start_xmit = gs_can_start_xmit,
+};
+
+static struct gs_can *gs_make_candev(unsigned int channel, struct usb_interface *intf)
+{
+	struct gs_can *dev;
+	struct net_device *netdev;
+	int rc;
+	struct gs_device_bt_const *bt_const;
+
+	bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
+	if (!bt_const)
+		return ERR_PTR(-ENOMEM);
+
+	/* fetch bit timing constants */
+	rc = usb_control_msg(interface_to_usbdev(intf),
+			     usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
+			     GS_USB_BREQ_BT_CONST,
+			     USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+			     channel,
+			     0,
+			     bt_const,
+			     sizeof(*bt_const),
+			     1000);
+
+	if (rc < 0) {
+		dev_err(&intf->dev,
+			"Couldn't get bit timing const for channel (err=%d)\n",
+			rc);
+		kfree(bt_const);
+		return ERR_PTR(rc);
+	}
+
+	/* create netdev */
+	netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
+	if (!netdev) {
+		dev_err(&intf->dev, "Couldn't allocate candev\n");
+		kfree(bt_const);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	dev = netdev_priv(netdev);
+
+	netdev->netdev_ops = &gs_usb_netdev_ops;
+
+	netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
+
+	/* dev settup */
+	strcpy(dev->bt_const.name, "gs_usb");
+	dev->bt_const.tseg1_min = bt_const->tseg1_min;
+	dev->bt_const.tseg1_max = bt_const->tseg1_max;
+	dev->bt_const.tseg2_min = bt_const->tseg2_min;
+	dev->bt_const.tseg2_max = bt_const->tseg2_max;
+	dev->bt_const.sjw_max = bt_const->sjw_max;
+	dev->bt_const.brp_min = bt_const->brp_min;
+	dev->bt_const.brp_max = bt_const->brp_max;
+	dev->bt_const.brp_inc = bt_const->brp_inc;
+
+	dev->udev = interface_to_usbdev(intf);
+	dev->iface = intf;
+	dev->netdev = netdev;
+	dev->channel = channel;
+
+	init_usb_anchor(&dev->tx_submitted);
+	atomic_set(&dev->active_tx_urbs, 0);
+	spin_lock_init(&dev->tx_ctx_lock);
+	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
+		dev->tx_context[rc].dev = dev;
+		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
+	}
+
+	/* can settup */
+	dev->can.state = CAN_STATE_STOPPED;
+	dev->can.clock.freq = bt_const->fclk_can;
+	dev->can.bittiming_const = &dev->bt_const;
+	dev->can.do_set_bittiming = gs_usb_set_bittiming;
+
+	dev->can.ctrlmode_supported = 0;
+
+	if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
+		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
+
+	if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
+		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
+
+	if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
+		dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
+
+	if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
+		dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
+
+	kfree(bt_const);
+
+	SET_NETDEV_DEV(netdev, &intf->dev);
+
+	rc = register_candev(dev->netdev);
+	if (rc) {
+		free_candev(dev->netdev);
+		dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
+		return ERR_PTR(rc);
+	}
+
+	return dev;
+}
+
+static void gs_destroy_candev(struct gs_can *dev)
+{
+	unregister_candev(dev->netdev);
+	free_candev(dev->netdev);
+	kfree(dev);
+	usb_kill_anchored_urbs(&dev->tx_submitted);
+}
+
+static int gs_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+	struct gs_usb *dev;
+	int rc = -ENOMEM;
+	unsigned int icount, i;
+	struct gs_host_config *hconf;
+	struct gs_device_config *dconf;
+
+	hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
+	if (!hconf)
+		return -ENOMEM;
+
+	hconf->byte_order = 0x0000beef;
+
+	/* send host config */
+	rc = usb_control_msg(interface_to_usbdev(intf),
+			     usb_sndctrlpipe(interface_to_usbdev(intf), 0),
+			     GS_USB_BREQ_HOST_FORMAT,
+			     USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+			     1,
+			     intf->altsetting[0].desc.bInterfaceNumber,
+			     hconf,
+			     sizeof(*hconf),
+			     1000);
+
+	kfree(hconf);
+
+	if (rc < 0) {
+		dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
+			rc);
+		return rc;
+	}
+
+	dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
+	if (!dconf)
+		return -ENOMEM;
+
+	/* read device config */
+	rc = usb_control_msg(interface_to_usbdev(intf),
+			     usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
+			     GS_USB_BREQ_DEVICE_CONFIG,
+			     USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+			     1,
+			     intf->altsetting[0].desc.bInterfaceNumber,
+			     dconf,
+			     sizeof(*dconf),
+			     1000);
+	if (rc < 0) {
+		dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
+			rc);
+
+		kfree(dconf);
+
+		return rc;
+	}
+
+	icount = dconf->icount+1;
+
+	kfree(dconf);
+
+	dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
+
+	if (icount > GS_MAX_INTF) {
+		dev_err(&intf->dev,
+			"Driver cannot handle more that %d CAN interfaces\n",
+			GS_MAX_INTF);
+		return -EINVAL;
+	}
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	init_usb_anchor(&dev->rx_submitted);
+
+	atomic_set(&dev->active_channels, 0);
+
+	usb_set_intfdata(intf, dev);
+	dev->udev = interface_to_usbdev(intf);
+
+	for (i = 0; i < icount; i++) {
+		dev->canch[i] = gs_make_candev(i, intf);
+		if (IS_ERR_OR_NULL(dev->canch[i])) {
+			/* on failure destroy previously created candevs */
+			icount = i;
+			for (i = 0; i < icount; i++) {
+				gs_destroy_candev(dev->canch[i]);
+				dev->canch[i] = NULL;
+			}
+			kfree(dev);
+			return rc;
+		}
+		dev->canch[i]->parent = dev;
+	}
+
+	return 0;
+}
+
+static void gs_usb_disconnect(struct usb_interface *intf)
+{
+	unsigned i;
+	struct gs_usb *dev = usb_get_intfdata(intf);
+	usb_set_intfdata(intf, NULL);
+
+	if (!dev) {
+		dev_err(&intf->dev, "Disconnect (nodata)\n");
+		return;
+	}
+
+	for (i = 0; i < GS_MAX_INTF; i++) {
+		struct gs_can *can = dev->canch[i];
+
+		if (!can)
+			continue;
+
+		gs_destroy_candev(can);
+	}
+
+	usb_kill_anchored_urbs(&dev->rx_submitted);
+}
+
+static const struct usb_device_id gs_usb_table[] = {
+	{USB_DEVICE(USB_GSUSB_1_VENDOR_ID, USB_GSUSB_1_PRODUCT_ID)},
+	{} /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, gs_usb_table);
+
+static struct usb_driver gs_usb_driver = {
+	.name       = "gs_usb",
+	.probe      = gs_usb_probe,
+	.disconnect = gs_usb_disconnect,
+	.id_table   = gs_usb_table,
+};
+
+module_usb_driver(gs_usb_driver);
+
+MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
+MODULE_DESCRIPTION(
+"Socket CAN device driver for Geschwister Schneider Technologie-, "
+"Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces.");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/can/core.h b/include/linux/can/core.h
index 78c6c52073ad..a0875001b13c 100644
--- a/include/linux/can/core.h
+++ b/include/linux/can/core.h
@@ -10,8 +10,8 @@
  *
  */
 
-#ifndef CAN_CORE_H
-#define CAN_CORE_H
+#ifndef _CAN_CORE_H
+#define _CAN_CORE_H
 
 #include <linux/can.h>
 #include <linux/skbuff.h>
@@ -58,4 +58,4 @@ extern void can_rx_unregister(struct net_device *dev, canid_t can_id,
 extern int can_send(struct sk_buff *skb, int loop);
 extern int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 
-#endif /* CAN_CORE_H */
+#endif /* !_CAN_CORE_H */
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 3ce5e526525f..6992afc6ba7f 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -10,8 +10,8 @@
  *
  */
 
-#ifndef CAN_DEV_H
-#define CAN_DEV_H
+#ifndef _CAN_DEV_H
+#define _CAN_DEV_H
 
 #include <linux/can.h>
 #include <linux/can/netlink.h>
@@ -132,4 +132,4 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 struct sk_buff *alloc_can_err_skb(struct net_device *dev,
 				  struct can_frame **cf);
 
-#endif /* CAN_DEV_H */
+#endif /* !_CAN_DEV_H */
diff --git a/include/linux/can/led.h b/include/linux/can/led.h
index 9c1167baf273..e0475c5cbb92 100644
--- a/include/linux/can/led.h
+++ b/include/linux/can/led.h
@@ -6,8 +6,8 @@
  * published by the Free Software Foundation.
  */
 
-#ifndef CAN_LED_H
-#define CAN_LED_H
+#ifndef _CAN_LED_H
+#define _CAN_LED_H
 
 #include <linux/if.h>
 #include <linux/leds.h>
@@ -48,4 +48,4 @@ static inline void can_led_notifier_exit(void)
 
 #endif
 
-#endif
+#endif /* !_CAN_LED_H */
diff --git a/include/linux/can/platform/cc770.h b/include/linux/can/platform/cc770.h
index 7702641f87ee..78b2d44f04cf 100644
--- a/include/linux/can/platform/cc770.h
+++ b/include/linux/can/platform/cc770.h
@@ -1,5 +1,5 @@
-#ifndef _CAN_PLATFORM_CC770_H_
-#define _CAN_PLATFORM_CC770_H_
+#ifndef _CAN_PLATFORM_CC770_H
+#define _CAN_PLATFORM_CC770_H
 
 /* CPU Interface Register (0x02) */
 #define CPUIF_CEN	0x01	/* Clock Out Enable */
@@ -30,4 +30,4 @@ struct cc770_platform_data {
 	u8 bcr;		/* Bus Configuration Register */
 };
 
-#endif	/* !_CAN_PLATFORM_CC770_H_ */
+#endif	/* !_CAN_PLATFORM_CC770_H */
diff --git a/include/linux/can/platform/mcp251x.h b/include/linux/can/platform/mcp251x.h
index dc029dba7a03..d44fcae274ff 100644
--- a/include/linux/can/platform/mcp251x.h
+++ b/include/linux/can/platform/mcp251x.h
@@ -1,5 +1,5 @@
-#ifndef __CAN_PLATFORM_MCP251X_H__
-#define __CAN_PLATFORM_MCP251X_H__
+#ifndef _CAN_PLATFORM_MCP251X_H
+#define _CAN_PLATFORM_MCP251X_H
 
 /*
  *
@@ -18,4 +18,4 @@ struct mcp251x_platform_data {
 	unsigned long oscillator_frequency;
 };
 
-#endif /* __CAN_PLATFORM_MCP251X_H__ */
+#endif /* !_CAN_PLATFORM_MCP251X_H */
diff --git a/include/linux/can/platform/rcar_can.h b/include/linux/can/platform/rcar_can.h
new file mode 100644
index 000000000000..0f4a2f3df504
--- /dev/null
+++ b/include/linux/can/platform/rcar_can.h
@@ -0,0 +1,17 @@
+#ifndef _CAN_PLATFORM_RCAR_CAN_H_
+#define _CAN_PLATFORM_RCAR_CAN_H_
+
+#include <linux/types.h>
+
+/* Clock Select Register settings */
+enum CLKR {
+	CLKR_CLKP1 = 0,	/* Peripheral clock (clkp1) */
+	CLKR_CLKP2 = 1,	/* Peripheral clock (clkp2) */
+	CLKR_CLKEXT = 3	/* Externally input clock */
+};
+
+struct rcar_can_platform_data {
+	enum CLKR clock_select;	/* Clock source select */
+};
+
+#endif	/* !_CAN_PLATFORM_RCAR_CAN_H_ */
diff --git a/include/linux/can/platform/sja1000.h b/include/linux/can/platform/sja1000.h
index 96f8fcc78d78..93570b61ec6c 100644
--- a/include/linux/can/platform/sja1000.h
+++ b/include/linux/can/platform/sja1000.h
@@ -1,5 +1,5 @@
-#ifndef _CAN_PLATFORM_SJA1000_H_
-#define _CAN_PLATFORM_SJA1000_H_
+#ifndef _CAN_PLATFORM_SJA1000_H
+#define _CAN_PLATFORM_SJA1000_H
 
 /* clock divider register */
 #define CDR_CLKOUT_MASK 0x07
@@ -32,4 +32,4 @@ struct sja1000_platform_data {
 	u8 cdr;		/* clock divider register */
 };
 
-#endif	/* !_CAN_PLATFORM_SJA1000_H_ */
+#endif	/* !_CAN_PLATFORM_SJA1000_H */
diff --git a/include/linux/can/platform/ti_hecc.h b/include/linux/can/platform/ti_hecc.h
index af17cb3f7a84..a52f47ca6c8a 100644
--- a/include/linux/can/platform/ti_hecc.h
+++ b/include/linux/can/platform/ti_hecc.h
@@ -1,5 +1,5 @@
-#ifndef __CAN_PLATFORM_TI_HECC_H__
-#define __CAN_PLATFORM_TI_HECC_H__
+#ifndef _CAN_PLATFORM_TI_HECC_H
+#define _CAN_PLATFORM_TI_HECC_H
 
 /*
  * TI HECC (High End CAN Controller) driver platform header
@@ -41,4 +41,4 @@ struct ti_hecc_platform_data {
 	u32 version;
 	void (*transceiver_switch) (int);
 };
-#endif
+#endif /* !_CAN_PLATFORM_TI_HECC_H */
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index f9bbbb472663..cc00d15c6107 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -7,8 +7,8 @@
  *
  */
 
-#ifndef CAN_SKB_H
-#define CAN_SKB_H
+#ifndef _CAN_SKB_H
+#define _CAN_SKB_H
 
 #include <linux/types.h>
 #include <linux/skbuff.h>
@@ -80,4 +80,4 @@ static inline struct sk_buff *can_create_echo_skb(struct sk_buff *skb)
 	return skb;
 }
 
-#endif /* CAN_SKB_H */
+#endif /* !_CAN_SKB_H */
diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h
index 5d9d1d140718..41892f720057 100644
--- a/include/uapi/linux/can.h
+++ b/include/uapi/linux/can.h
@@ -42,8 +42,8 @@
  * DAMAGE.
  */
 
-#ifndef CAN_H
-#define CAN_H
+#ifndef _UAPI_CAN_H
+#define _UAPI_CAN_H
 
 #include <linux/types.h>
 #include <linux/socket.h>
@@ -191,4 +191,4 @@ struct can_filter {
 
 #define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */
 
-#endif /* CAN_H */
+#endif /* !_UAPI_CAN_H */
diff --git a/include/uapi/linux/can/bcm.h b/include/uapi/linux/can/bcm.h
index 382251a1d214..89ddb9dc9bdf 100644
--- a/include/uapi/linux/can/bcm.h
+++ b/include/uapi/linux/can/bcm.h
@@ -41,8 +41,8 @@
  * DAMAGE.
  */
 
-#ifndef CAN_BCM_H
-#define CAN_BCM_H
+#ifndef _UAPI_CAN_BCM_H
+#define _UAPI_CAN_BCM_H
 
 #include <linux/types.h>
 #include <linux/can.h>
@@ -95,4 +95,4 @@ enum {
 #define TX_RESET_MULTI_IDX  0x0200
 #define RX_RTR_FRAME        0x0400
 
-#endif /* CAN_BCM_H */
+#endif /* !_UAPI_CAN_BCM_H */
diff --git a/include/uapi/linux/can/error.h b/include/uapi/linux/can/error.h
index b63204545320..c247446ab25a 100644
--- a/include/uapi/linux/can/error.h
+++ b/include/uapi/linux/can/error.h
@@ -41,8 +41,8 @@
  * DAMAGE.
  */
 
-#ifndef CAN_ERROR_H
-#define CAN_ERROR_H
+#ifndef _UAPI_CAN_ERROR_H
+#define _UAPI_CAN_ERROR_H
 
 #define CAN_ERR_DLC 8 /* dlc for error message frames */
 
@@ -120,4 +120,4 @@
 
 /* controller specific additional information / data[5..7] */
 
-#endif /* CAN_ERROR_H */
+#endif /* _UAPI_CAN_ERROR_H */
diff --git a/include/uapi/linux/can/gw.h b/include/uapi/linux/can/gw.h
index 844c8964bdfe..3e6184cf2f6d 100644
--- a/include/uapi/linux/can/gw.h
+++ b/include/uapi/linux/can/gw.h
@@ -41,8 +41,8 @@
  * DAMAGE.
  */
 
-#ifndef CAN_GW_H
-#define CAN_GW_H
+#ifndef _UAPI_CAN_GW_H
+#define _UAPI_CAN_GW_H
 
 #include <linux/types.h>
 #include <linux/can.h>
@@ -200,4 +200,4 @@ enum {
  *         Beware of sending unpacked or aligned structs!
  */
 
-#endif
+#endif /* !_UAPI_CAN_GW_H */
diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h
index 7e2e1863db16..813d11f54977 100644
--- a/include/uapi/linux/can/netlink.h
+++ b/include/uapi/linux/can/netlink.h
@@ -15,8 +15,8 @@
  * GNU General Public License for more details.
  */
 
-#ifndef CAN_NETLINK_H
-#define CAN_NETLINK_H
+#ifndef _UAPI_CAN_NETLINK_H
+#define _UAPI_CAN_NETLINK_H
 
 #include <linux/types.h>
 
@@ -130,4 +130,4 @@ enum {
 
 #define IFLA_CAN_MAX	(__IFLA_CAN_MAX - 1)
 
-#endif /* CAN_NETLINK_H */
+#endif /* !_UAPI_CAN_NETLINK_H */
diff --git a/include/uapi/linux/can/raw.h b/include/uapi/linux/can/raw.h
index c7d8c334e0ce..78ec76fd89a6 100644
--- a/include/uapi/linux/can/raw.h
+++ b/include/uapi/linux/can/raw.h
@@ -42,8 +42,8 @@
  * DAMAGE.
  */
 
-#ifndef CAN_RAW_H
-#define CAN_RAW_H
+#ifndef _UAPI_CAN_RAW_H
+#define _UAPI_CAN_RAW_H
 
 #include <linux/can.h>
 
@@ -59,4 +59,4 @@ enum {
 	CAN_RAW_FD_FRAMES,	/* allow CAN FD frames (default:off) */
 };
 
-#endif
+#endif /* !_UAPI_CAN_RAW_H */
diff --git a/net/can/af_can.c b/net/can/af_can.c
index a27f8aad9e99..ce82337521f6 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -338,6 +338,29 @@ static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
 }
 
 /**
+ * effhash - hash function for 29 bit CAN identifier reduction
+ * @can_id: 29 bit CAN identifier
+ *
+ * Description:
+ *  To reduce the linear traversal in one linked list of _single_ EFF CAN
+ *  frame subscriptions the 29 bit identifier is mapped to 10 bits.
+ *  (see CAN_EFF_RCV_HASH_BITS definition)
+ *
+ * Return:
+ *  Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
+ */
+static unsigned int effhash(canid_t can_id)
+{
+	unsigned int hash;
+
+	hash = can_id;
+	hash ^= can_id >> CAN_EFF_RCV_HASH_BITS;
+	hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS);
+
+	return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);
+}
+
+/**
  * find_rcv_list - determine optimal filterlist inside device filter struct
  * @can_id: pointer to CAN identifier of a given can_filter
  * @mask: pointer to CAN mask of a given can_filter
@@ -400,10 +423,8 @@ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
 	    !(*can_id & CAN_RTR_FLAG)) {
 
 		if (*can_id & CAN_EFF_FLAG) {
-			if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) {
-				/* RFC: a future use-case for hash-tables? */
-				return &d->rx[RX_EFF];
-			}
+			if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS))
+				return &d->rx_eff[effhash(*can_id)];
 		} else {
 			if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
 				return &d->rx_sff[*can_id];
@@ -632,7 +653,7 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
 		return matches;
 
 	if (can_id & CAN_EFF_FLAG) {
-		hlist_for_each_entry_rcu(r, &d->rx[RX_EFF], list) {
+		hlist_for_each_entry_rcu(r, &d->rx_eff[effhash(can_id)], list) {
 			if (r->can_id == can_id) {
 				deliver(skb, r);
 				matches++;
diff --git a/net/can/af_can.h b/net/can/af_can.h
index 6de58b40535c..fca0fe9fc45a 100644
--- a/net/can/af_can.h
+++ b/net/can/af_can.h
@@ -59,12 +59,17 @@ struct receiver {
 	char *ident;
 };
 
-enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_EFF, RX_MAX };
+#define CAN_SFF_RCV_ARRAY_SZ (1 << CAN_SFF_ID_BITS)
+#define CAN_EFF_RCV_HASH_BITS 10
+#define CAN_EFF_RCV_ARRAY_SZ (1 << CAN_EFF_RCV_HASH_BITS)
+
+enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_MAX };
 
 /* per device receive filters linked at dev->ml_priv */
 struct dev_rcv_lists {
 	struct hlist_head rx[RX_MAX];
-	struct hlist_head rx_sff[0x800];
+	struct hlist_head rx_sff[CAN_SFF_RCV_ARRAY_SZ];
+	struct hlist_head rx_eff[CAN_EFF_RCV_ARRAY_SZ];
 	int remove_on_zero_entries;
 	int entries;
 };
diff --git a/net/can/proc.c b/net/can/proc.c
index b543470c8f8b..1a19b985a868 100644
--- a/net/can/proc.c
+++ b/net/can/proc.c
@@ -80,7 +80,6 @@ static const char rx_list_name[][8] = {
 	[RX_ALL] = "rx_all",
 	[RX_FIL] = "rx_fil",
 	[RX_INV] = "rx_inv",
-	[RX_EFF] = "rx_eff",
 };
 
 /*
@@ -389,25 +388,26 @@ static const struct file_operations can_rcvlist_proc_fops = {
 	.release	= single_release,
 };
 
-static inline void can_rcvlist_sff_proc_show_one(struct seq_file *m,
-						 struct net_device *dev,
-						 struct dev_rcv_lists *d)
+static inline void can_rcvlist_proc_show_array(struct seq_file *m,
+					       struct net_device *dev,
+					       struct hlist_head *rcv_array,
+					       unsigned int rcv_array_sz)
 {
-	int i;
+	unsigned int i;
 	int all_empty = 1;
 
 	/* check whether at least one list is non-empty */
-	for (i = 0; i < 0x800; i++)
-		if (!hlist_empty(&d->rx_sff[i])) {
+	for (i = 0; i < rcv_array_sz; i++)
+		if (!hlist_empty(&rcv_array[i])) {
 			all_empty = 0;
 			break;
 		}
 
 	if (!all_empty) {
 		can_print_recv_banner(m);
-		for (i = 0; i < 0x800; i++) {
-			if (!hlist_empty(&d->rx_sff[i]))
-				can_print_rcvlist(m, &d->rx_sff[i], dev);
+		for (i = 0; i < rcv_array_sz; i++) {
+			if (!hlist_empty(&rcv_array[i]))
+				can_print_rcvlist(m, &rcv_array[i], dev);
 		}
 	} else
 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
@@ -425,12 +425,15 @@ static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
 
 	/* sff receive list for 'all' CAN devices (dev == NULL) */
 	d = &can_rx_alldev_list;
-	can_rcvlist_sff_proc_show_one(m, NULL, d);
+	can_rcvlist_proc_show_array(m, NULL, d->rx_sff, ARRAY_SIZE(d->rx_sff));
 
 	/* sff receive list for registered CAN devices */
 	for_each_netdev_rcu(&init_net, dev) {
-		if (dev->type == ARPHRD_CAN && dev->ml_priv)
-			can_rcvlist_sff_proc_show_one(m, dev, dev->ml_priv);
+		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
+			d = dev->ml_priv;
+			can_rcvlist_proc_show_array(m, dev, d->rx_sff,
+						    ARRAY_SIZE(d->rx_sff));
+		}
 	}
 
 	rcu_read_unlock();
@@ -452,6 +455,49 @@ static const struct file_operations can_rcvlist_sff_proc_fops = {
 	.release	= single_release,
 };
 
+
+static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
+{
+	struct net_device *dev;
+	struct dev_rcv_lists *d;
+
+	/* RX_EFF */
+	seq_puts(m, "\nreceive list 'rx_eff':\n");
+
+	rcu_read_lock();
+
+	/* eff receive list for 'all' CAN devices (dev == NULL) */
+	d = &can_rx_alldev_list;
+	can_rcvlist_proc_show_array(m, NULL, d->rx_eff, ARRAY_SIZE(d->rx_eff));
+
+	/* eff receive list for registered CAN devices */
+	for_each_netdev_rcu(&init_net, dev) {
+		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
+			d = dev->ml_priv;
+			can_rcvlist_proc_show_array(m, dev, d->rx_eff,
+						    ARRAY_SIZE(d->rx_eff));
+		}
+	}
+
+	rcu_read_unlock();
+
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static int can_rcvlist_eff_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, can_rcvlist_eff_proc_show, NULL);
+}
+
+static const struct file_operations can_rcvlist_eff_proc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= can_rcvlist_eff_proc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
 /*
  * proc utility functions
  */
@@ -491,8 +537,8 @@ void can_init_proc(void)
 					   &can_rcvlist_proc_fops, (void *)RX_FIL);
 	pde_rcvlist_inv = proc_create_data(CAN_PROC_RCVLIST_INV, 0644, can_dir,
 					   &can_rcvlist_proc_fops, (void *)RX_INV);
-	pde_rcvlist_eff = proc_create_data(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
-					   &can_rcvlist_proc_fops, (void *)RX_EFF);
+	pde_rcvlist_eff = proc_create(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
+				      &can_rcvlist_eff_proc_fops);
 	pde_rcvlist_sff = proc_create(CAN_PROC_RCVLIST_SFF, 0644, can_dir,
 				      &can_rcvlist_sff_proc_fops);
 }