can: tcan4x5x: Add tcan4x5x driver to the kernel

Add the TCAN4x5x SPI CAN driver.

This device uses the Bosch MCAN IP core along with a SPI interface map.
Register to the MCAN common core code to manage the MCAN IP.

This device has a special method to indicate a write/read operation on
the data payload.

Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

3 files changed, 542 insertions, 0 deletions

diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
index 306c75dc7913..1ff0b7fe81d6 100644
--- a/drivers/net/can/m_can/Kconfig
+++ b/drivers/net/can/m_can/Kconfig
@@ -13,3 +13,12 @@ config CAN_M_CAN_PLATFORM
 	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
 	  This support is for devices that have the Bosch M_CAN controller
 	  IP embedded into the device and the IP is IO Mapped to the processor.
+
+config CAN_M_CAN_TCAN4X5X
+	depends on CAN_M_CAN
+	depends on REGMAP_SPI
+	tristate "TCAN4X5X M_CAN device"
+	---help---
+	  Say Y here if you want support for Texas Instruments TCAN4x5x
+	  M_CAN controller.  This device is a peripherial device that uses the
+	  SPI bus for communication.
diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
index ac568be3de98..52a4a6fbe527 100644
--- a/drivers/net/can/m_can/Makefile
+++ b/drivers/net/can/m_can/Makefile
@@ -5,3 +5,4 @@
 
 obj-$(CONFIG_CAN_M_CAN) += m_can.o
 obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
+obj-$(CONFIG_CAN_M_CAN_TCAN4X5X) += tcan4x5x.o
diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
new file mode 100644
index 000000000000..b115b2e5333f
--- /dev/null
+++ b/drivers/net/can/m_can/tcan4x5x.c
@@ -0,0 +1,532 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPI to CAN driver for the Texas Instruments TCAN4x5x
+// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
+
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
+
+#include "m_can.h"
+
+#define DEVICE_NAME "tcan4x5x"
+#define TCAN4X5X_EXT_CLK_DEF 40000000
+
+#define TCAN4X5X_DEV_ID0 0x00
+#define TCAN4X5X_DEV_ID1 0x04
+#define TCAN4X5X_REV 0x08
+#define TCAN4X5X_STATUS 0x0C
+#define TCAN4X5X_ERROR_STATUS 0x10
+#define TCAN4X5X_CONTROL 0x14
+
+#define TCAN4X5X_CONFIG 0x800
+#define TCAN4X5X_TS_PRESCALE 0x804
+#define TCAN4X5X_TEST_REG 0x808
+#define TCAN4X5X_INT_FLAGS 0x820
+#define TCAN4X5X_MCAN_INT_REG 0x824
+#define TCAN4X5X_INT_EN 0x830
+
+/* Interrupt bits */
+#define TCAN4X5X_CANBUSTERMOPEN_INT_EN BIT(30)
+#define TCAN4X5X_CANHCANL_INT_EN BIT(29)
+#define TCAN4X5X_CANHBAT_INT_EN BIT(28)
+#define TCAN4X5X_CANLGND_INT_EN BIT(27)
+#define TCAN4X5X_CANBUSOPEN_INT_EN BIT(26)
+#define TCAN4X5X_CANBUSGND_INT_EN BIT(25)
+#define TCAN4X5X_CANBUSBAT_INT_EN BIT(24)
+#define TCAN4X5X_UVSUP_INT_EN BIT(22)
+#define TCAN4X5X_UVIO_INT_EN BIT(21)
+#define TCAN4X5X_TSD_INT_EN BIT(19)
+#define TCAN4X5X_ECCERR_INT_EN BIT(16)
+#define TCAN4X5X_CANINT_INT_EN BIT(15)
+#define TCAN4X5X_LWU_INT_EN BIT(14)
+#define TCAN4X5X_CANSLNT_INT_EN BIT(10)
+#define TCAN4X5X_CANDOM_INT_EN BIT(8)
+#define TCAN4X5X_CANBUS_ERR_INT_EN BIT(5)
+#define TCAN4X5X_BUS_FAULT BIT(4)
+#define TCAN4X5X_MCAN_INT BIT(1)
+#define TCAN4X5X_ENABLE_TCAN_INT \
+	(TCAN4X5X_MCAN_INT | TCAN4X5X_BUS_FAULT | \
+	 TCAN4X5X_CANBUS_ERR_INT_EN | TCAN4X5X_CANINT_INT_EN)
+
+/* MCAN Interrupt bits */
+#define TCAN4X5X_MCAN_IR_ARA BIT(29)
+#define TCAN4X5X_MCAN_IR_PED BIT(28)
+#define TCAN4X5X_MCAN_IR_PEA BIT(27)
+#define TCAN4X5X_MCAN_IR_WD BIT(26)
+#define TCAN4X5X_MCAN_IR_BO BIT(25)
+#define TCAN4X5X_MCAN_IR_EW BIT(24)
+#define TCAN4X5X_MCAN_IR_EP BIT(23)
+#define TCAN4X5X_MCAN_IR_ELO BIT(22)
+#define TCAN4X5X_MCAN_IR_BEU BIT(21)
+#define TCAN4X5X_MCAN_IR_BEC BIT(20)
+#define TCAN4X5X_MCAN_IR_DRX BIT(19)
+#define TCAN4X5X_MCAN_IR_TOO BIT(18)
+#define TCAN4X5X_MCAN_IR_MRAF BIT(17)
+#define TCAN4X5X_MCAN_IR_TSW BIT(16)
+#define TCAN4X5X_MCAN_IR_TEFL BIT(15)
+#define TCAN4X5X_MCAN_IR_TEFF BIT(14)
+#define TCAN4X5X_MCAN_IR_TEFW BIT(13)
+#define TCAN4X5X_MCAN_IR_TEFN BIT(12)
+#define TCAN4X5X_MCAN_IR_TFE BIT(11)
+#define TCAN4X5X_MCAN_IR_TCF BIT(10)
+#define TCAN4X5X_MCAN_IR_TC BIT(9)
+#define TCAN4X5X_MCAN_IR_HPM BIT(8)
+#define TCAN4X5X_MCAN_IR_RF1L BIT(7)
+#define TCAN4X5X_MCAN_IR_RF1F BIT(6)
+#define TCAN4X5X_MCAN_IR_RF1W BIT(5)
+#define TCAN4X5X_MCAN_IR_RF1N BIT(4)
+#define TCAN4X5X_MCAN_IR_RF0L BIT(3)
+#define TCAN4X5X_MCAN_IR_RF0F BIT(2)
+#define TCAN4X5X_MCAN_IR_RF0W BIT(1)
+#define TCAN4X5X_MCAN_IR_RF0N BIT(0)
+#define TCAN4X5X_ENABLE_MCAN_INT \
+	(TCAN4X5X_MCAN_IR_TC | TCAN4X5X_MCAN_IR_RF0N | \
+	 TCAN4X5X_MCAN_IR_RF1N | TCAN4X5X_MCAN_IR_RF0F | \
+	 TCAN4X5X_MCAN_IR_RF1F)
+
+#define TCAN4X5X_MRAM_START 0x8000
+#define TCAN4X5X_MCAN_OFFSET 0x1000
+#define TCAN4X5X_MAX_REGISTER 0x8fff
+
+#define TCAN4X5X_CLEAR_ALL_INT 0xffffffff
+#define TCAN4X5X_SET_ALL_INT 0xffffffff
+
+#define TCAN4X5X_WRITE_CMD (0x61 << 24)
+#define TCAN4X5X_READ_CMD (0x41 << 24)
+
+#define TCAN4X5X_MODE_SEL_MASK (BIT(7) | BIT(6))
+#define TCAN4X5X_MODE_SLEEP 0x00
+#define TCAN4X5X_MODE_STANDBY BIT(6)
+#define TCAN4X5X_MODE_NORMAL BIT(7)
+
+#define TCAN4X5X_SW_RESET BIT(2)
+
+#define TCAN4X5X_MCAN_CONFIGURED BIT(5)
+#define TCAN4X5X_WATCHDOG_EN BIT(3)
+#define TCAN4X5X_WD_60_MS_TIMER 0
+#define TCAN4X5X_WD_600_MS_TIMER BIT(28)
+#define TCAN4X5X_WD_3_S_TIMER BIT(29)
+#define TCAN4X5X_WD_6_S_TIMER (BIT(28) | BIT(29))
+
+struct tcan4x5x_priv {
+	struct regmap *regmap;
+	struct spi_device *spi;
+	struct mutex tcan4x5x_lock; /* SPI device lock */
+
+	struct m_can_classdev *mcan_dev;
+
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *interrupt_gpio;
+	struct gpio_desc *device_wake_gpio;
+	struct gpio_desc *device_state_gpio;
+	struct regulator *power;
+
+	/* Register based ip */
+	int mram_start;
+	int reg_offset;
+};
+
+static struct can_bittiming_const tcan4x5x_bittiming_const = {
+	.name = DEVICE_NAME,
+	.tseg1_min = 2,
+	.tseg1_max = 31,
+	.tseg2_min = 2,
+	.tseg2_max = 16,
+	.sjw_max = 16,
+	.brp_min = 1,
+	.brp_max = 32,
+	.brp_inc = 1,
+};
+
+static struct can_bittiming_const tcan4x5x_data_bittiming_const = {
+	.name = DEVICE_NAME,
+	.tseg1_min = 1,
+	.tseg1_max = 32,
+	.tseg2_min = 1,
+	.tseg2_max = 16,
+	.sjw_max = 16,
+	.brp_min = 1,
+	.brp_max = 32,
+	.brp_inc = 1,
+};
+
+static void tcan4x5x_check_wake(struct tcan4x5x_priv *priv)
+{
+	int wake_state = 0;
+
+	if (priv->device_state_gpio)
+		wake_state = gpiod_get_value(priv->device_state_gpio);
+
+	if (priv->device_wake_gpio && wake_state) {
+		gpiod_set_value(priv->device_wake_gpio, 0);
+		usleep_range(5, 50);
+		gpiod_set_value(priv->device_wake_gpio, 1);
+	}
+}
+
+static int regmap_spi_gather_write(void *context, const void *reg,
+				   size_t reg_len, const void *val,
+				   size_t val_len)
+{
+	struct device *dev = context;
+	struct spi_device *spi = to_spi_device(dev);
+	struct spi_message m;
+	u32 addr;
+	struct spi_transfer t[2] = {
+		{ .tx_buf = &addr, .len = reg_len, .cs_change = 0,},
+		{ .tx_buf = val, .len = val_len, },
+	};
+
+	addr = TCAN4X5X_WRITE_CMD | (*((u16 *)reg) << 8) | val_len >> 3;
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t[0], &m);
+	spi_message_add_tail(&t[1], &m);
+
+	return spi_sync(spi, &m);
+}
+
+static int tcan4x5x_regmap_write(void *context, const void *data, size_t count)
+{
+	u16 *reg = (u16 *)(data);
+	const u32 *val = data + 4;
+
+	return regmap_spi_gather_write(context, reg, 4, val, count);
+}
+
+static int regmap_spi_async_write(void *context,
+				  const void *reg, size_t reg_len,
+				  const void *val, size_t val_len,
+				  struct regmap_async *a)
+{
+	return -ENOTSUPP;
+}
+
+static struct regmap_async *regmap_spi_async_alloc(void)
+{
+	return NULL;
+}
+
+static int tcan4x5x_regmap_read(void *context,
+				const void *reg, size_t reg_size,
+				void *val, size_t val_size)
+{
+	struct device *dev = context;
+	struct spi_device *spi = to_spi_device(dev);
+
+	u32 addr = TCAN4X5X_READ_CMD | (*((u16 *)reg) << 8) | val_size >> 2;
+
+	return spi_write_then_read(spi, &addr, reg_size, (u32 *)val, val_size);
+}
+
+static struct regmap_bus tcan4x5x_bus = {
+	.write = tcan4x5x_regmap_write,
+	.gather_write = regmap_spi_gather_write,
+	.async_write = regmap_spi_async_write,
+	.async_alloc = regmap_spi_async_alloc,
+	.read = tcan4x5x_regmap_read,
+	.read_flag_mask = 0x00,
+	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+static u32 tcan4x5x_read_reg(struct m_can_classdev *cdev, int reg)
+{
+	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)cdev->device_data;
+	u32 val;
+
+	tcan4x5x_check_wake(priv);
+
+	regmap_read(priv->regmap, priv->reg_offset + reg, &val);
+
+	return val;
+}
+
+static u32 tcan4x5x_read_fifo(struct m_can_classdev *cdev, int addr_offset)
+{
+	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)cdev->device_data;
+	u32 val;
+
+	tcan4x5x_check_wake(priv);
+
+	regmap_read(priv->regmap, priv->mram_start + addr_offset, &val);
+
+	return val;
+}
+
+static int tcan4x5x_write_reg(struct m_can_classdev *cdev, int reg, int val)
+{
+	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)cdev->device_data;
+
+	tcan4x5x_check_wake(priv);
+
+	return regmap_write(priv->regmap, priv->reg_offset + reg, val);
+}
+
+static int tcan4x5x_write_fifo(struct m_can_classdev *cdev,
+			       int addr_offset, int val)
+{
+	struct tcan4x5x_priv *priv =
+			(struct tcan4x5x_priv *)cdev->device_data;
+
+	tcan4x5x_check_wake(priv);
+
+	return regmap_write(priv->regmap, priv->mram_start + addr_offset, val);
+}
+
+static int tcan4x5x_power_enable(struct regulator *reg, int enable)
+{
+	if (IS_ERR_OR_NULL(reg))
+		return 0;
+
+	if (enable)
+		return regulator_enable(reg);
+	else
+		return regulator_disable(reg);
+}
+
+static int tcan4x5x_write_tcan_reg(struct m_can_classdev *cdev,
+				   int reg, int val)
+{
+	struct tcan4x5x_priv *priv =
+			(struct tcan4x5x_priv *)cdev->device_data;
+
+	tcan4x5x_check_wake(priv);
+
+	return regmap_write(priv->regmap, reg, val);
+}
+
+static int tcan4x5x_clear_interrupts(struct m_can_classdev *cdev)
+{
+	struct tcan4x5x_priv *tcan4x5x =
+				(struct tcan4x5x_priv *)cdev->device_data;
+	int ret;
+
+	tcan4x5x_check_wake(tcan4x5x);
+
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_STATUS,
+				      TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return ret;
+
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_MCAN_INT_REG,
+				      TCAN4X5X_ENABLE_MCAN_INT);
+	if (ret)
+		return ret;
+
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_FLAGS,
+				      TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return ret;
+
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS,
+				      TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return ret;
+
+	return ret;
+}
+
+static int tcan4x5x_init(struct m_can_classdev *cdev)
+{
+	struct tcan4x5x_priv *tcan4x5x =
+				(struct tcan4x5x_priv *)cdev->device_data;
+	int ret;
+
+	tcan4x5x_check_wake(tcan4x5x);
+
+	ret = tcan4x5x_clear_interrupts(cdev);
+	if (ret)
+		return ret;
+
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_EN,
+				      TCAN4X5X_ENABLE_TCAN_INT);
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
+				 TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
+	if (ret)
+		return ret;
+
+	/* Zero out the MCAN buffers */
+	m_can_init_ram(cdev);
+
+	return ret;
+}
+
+static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
+{
+	struct tcan4x5x_priv *tcan4x5x =
+				(struct tcan4x5x_priv *)cdev->device_data;
+
+	tcan4x5x->interrupt_gpio = devm_gpiod_get(cdev->dev, "data-ready",
+						  GPIOD_IN);
+	if (IS_ERR(tcan4x5x->interrupt_gpio)) {
+		dev_err(cdev->dev, "data-ready gpio not defined\n");
+		return -EINVAL;
+	}
+
+	tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
+						    GPIOD_OUT_HIGH);
+	if (IS_ERR(tcan4x5x->device_wake_gpio)) {
+		dev_err(cdev->dev, "device-wake gpio not defined\n");
+		return -EINVAL;
+	}
+
+	tcan4x5x->reset_gpio = devm_gpiod_get_optional(cdev->dev, "reset",
+						       GPIOD_OUT_LOW);
+	if (IS_ERR(tcan4x5x->reset_gpio))
+		tcan4x5x->reset_gpio = NULL;
+
+	tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
+							      "device-state",
+							      GPIOD_IN);
+	if (IS_ERR(tcan4x5x->device_state_gpio))
+		tcan4x5x->device_state_gpio = NULL;
+
+	cdev->net->irq = gpiod_to_irq(tcan4x5x->interrupt_gpio);
+
+	tcan4x5x->power = devm_regulator_get_optional(cdev->dev,
+						      "vsup");
+	if (PTR_ERR(tcan4x5x->power) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	return 0;
+}
+
+static const struct regmap_config tcan4x5x_regmap = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.cache_type = REGCACHE_NONE,
+	.max_register = TCAN4X5X_MAX_REGISTER,
+};
+
+static struct m_can_ops tcan4x5x_ops = {
+	.init = tcan4x5x_init,
+	.read_reg = tcan4x5x_read_reg,
+	.write_reg = tcan4x5x_write_reg,
+	.write_fifo = tcan4x5x_write_fifo,
+	.read_fifo = tcan4x5x_read_fifo,
+	.clear_interrupts = tcan4x5x_clear_interrupts,
+};
+
+static int tcan4x5x_can_probe(struct spi_device *spi)
+{
+	struct tcan4x5x_priv *priv;
+	struct m_can_classdev *mcan_class;
+	int freq, ret;
+
+	mcan_class = m_can_class_allocate_dev(&spi->dev);
+	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mcan_class->device_data = priv;
+
+	m_can_class_get_clocks(mcan_class);
+	if (IS_ERR(mcan_class->cclk)) {
+		dev_err(&spi->dev, "no CAN clock source defined\n");
+		freq = TCAN4X5X_EXT_CLK_DEF;
+	} else {
+		freq = clk_get_rate(mcan_class->cclk);
+	}
+
+	/* Sanity check */
+	if (freq < 20000000 || freq > TCAN4X5X_EXT_CLK_DEF)
+		return -ERANGE;
+
+	priv->reg_offset = TCAN4X5X_MCAN_OFFSET;
+	priv->mram_start = TCAN4X5X_MRAM_START;
+	priv->spi = spi;
+	priv->mcan_dev = mcan_class;
+
+	mcan_class->pm_clock_support = 0;
+	mcan_class->can.clock.freq = freq;
+	mcan_class->dev = &spi->dev;
+	mcan_class->ops = &tcan4x5x_ops;
+	mcan_class->is_peripheral = true;
+	mcan_class->bit_timing = &tcan4x5x_bittiming_const;
+	mcan_class->data_timing = &tcan4x5x_data_bittiming_const;
+
+	spi_set_drvdata(spi, priv);
+
+	ret = tcan4x5x_parse_config(mcan_class);
+	if (ret)
+		goto out_clk;
+
+	/* Configure the SPI bus */
+	spi->bits_per_word = 32;
+	ret = spi_setup(spi);
+	if (ret)
+		goto out_clk;
+
+	priv->regmap = devm_regmap_init(&spi->dev, &tcan4x5x_bus,
+					&spi->dev, &tcan4x5x_regmap);
+
+	mutex_init(&priv->tcan4x5x_lock);
+
+	tcan4x5x_power_enable(priv->power, 1);
+
+	ret = m_can_class_register(mcan_class);
+	if (ret)
+		goto out_power;
+
+	netdev_info(mcan_class->net, "TCAN4X5X successfully initialized.\n");
+	return 0;
+
+out_power:
+	tcan4x5x_power_enable(priv->power, 0);
+out_clk:
+	if (!IS_ERR(mcan_class->cclk)) {
+		clk_disable_unprepare(mcan_class->cclk);
+		clk_disable_unprepare(mcan_class->hclk);
+	}
+
+	dev_err(&spi->dev, "Probe failed, err=%d\n", ret);
+	return ret;
+}
+
+static int tcan4x5x_can_remove(struct spi_device *spi)
+{
+	struct tcan4x5x_priv *priv = spi_get_drvdata(spi);
+
+	tcan4x5x_power_enable(priv->power, 0);
+
+	m_can_class_unregister(priv->mcan_dev);
+
+	return 0;
+}
+
+static const struct of_device_id tcan4x5x_of_match[] = {
+	{ .compatible = "ti,tcan4x5x", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tcan4x5x_of_match);
+
+static const struct spi_device_id tcan4x5x_id_table[] = {
+	{
+		.name		= "tcan4x5x",
+		.driver_data	= 0,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, tcan4x5x_id_table);
+
+static struct spi_driver tcan4x5x_can_driver = {
+	.driver = {
+		.name = DEVICE_NAME,
+		.of_match_table = tcan4x5x_of_match,
+		.pm = NULL,
+	},
+	.id_table = tcan4x5x_id_table,
+	.probe = tcan4x5x_can_probe,
+	.remove = tcan4x5x_can_remove,
+};
+module_spi_driver(tcan4x5x_can_driver);
+
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
+MODULE_DESCRIPTION("Texas Instruments TCAN4x5x CAN driver");
+MODULE_LICENSE("GPL v2");