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// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for CC770 and AN82527 CAN controllers on the platform bus
*
* Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
*/
/*
* If platform data are used you should have similar definitions
* in your board-specific code:
*
* static struct cc770_platform_data myboard_cc770_pdata = {
* .osc_freq = 16000000,
* .cir = 0x41,
* .cor = 0x20,
* .bcr = 0x40,
* };
*
* Please see include/linux/can/platform/cc770.h for description of
* above fields.
*
* If the device tree is used, you need a CAN node definition in your
* DTS file similar to:
*
* can@3,100 {
* compatible = "bosch,cc770";
* reg = <3 0x100 0x80>;
* interrupts = <2 0>;
* interrupt-parent = <&mpic>;
* bosch,external-clock-frequency = <16000000>;
* };
*
* See "Documentation/devicetree/bindings/net/can/cc770.txt" for further
* information.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/platform/cc770.h>
#include "cc770.h"
#define DRV_NAME "cc770_platform"
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the platform bus");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRV_NAME);
#define CC770_PLATFORM_CAN_CLOCK 16000000
static u8 cc770_platform_read_reg(const struct cc770_priv *priv, int reg)
{
return ioread8(priv->reg_base + reg);
}
static void cc770_platform_write_reg(const struct cc770_priv *priv, int reg,
u8 val)
{
iowrite8(val, priv->reg_base + reg);
}
static int cc770_get_of_node_data(struct platform_device *pdev,
struct cc770_priv *priv)
{
u32 clkext = CC770_PLATFORM_CAN_CLOCK, clkout = 0;
struct device_node *np = pdev->dev.of_node;
of_property_read_u32(np, "bosch,external-clock-frequency", &clkext);
priv->can.clock.freq = clkext;
/* The system clock may not exceed 10 MHz */
if (priv->can.clock.freq > 10000000) {
priv->cpu_interface |= CPUIF_DSC;
priv->can.clock.freq /= 2;
}
/* The memory clock may not exceed 8 MHz */
if (priv->can.clock.freq > 8000000)
priv->cpu_interface |= CPUIF_DMC;
if (of_property_read_bool(np, "bosch,divide-memory-clock"))
priv->cpu_interface |= CPUIF_DMC;
if (of_property_read_bool(np, "bosch,iso-low-speed-mux"))
priv->cpu_interface |= CPUIF_MUX;
if (!of_property_read_bool(np, "bosch,no-comperator-bypass"))
priv->bus_config |= BUSCFG_CBY;
if (of_property_read_bool(np, "bosch,disconnect-rx0-input"))
priv->bus_config |= BUSCFG_DR0;
if (of_property_read_bool(np, "bosch,disconnect-rx1-input"))
priv->bus_config |= BUSCFG_DR1;
if (of_property_read_bool(np, "bosch,disconnect-tx1-output"))
priv->bus_config |= BUSCFG_DT1;
if (of_property_read_bool(np, "bosch,polarity-dominant"))
priv->bus_config |= BUSCFG_POL;
of_property_read_u32(np, "bosch,clock-out-frequency", &clkout);
if (clkout > 0) {
u32 cdv = clkext / clkout;
if (cdv > 0 && cdv < 16) {
u32 slew;
priv->cpu_interface |= CPUIF_CEN;
priv->clkout |= (cdv - 1) & CLKOUT_CD_MASK;
if (of_property_read_u32(np, "bosch,slew-rate", &slew)) {
/* Determine default slew rate */
slew = (CLKOUT_SL_MASK >>
CLKOUT_SL_SHIFT) -
((cdv * clkext - 1) / 8000000);
if (slew > (CLKOUT_SL_MASK >> CLKOUT_SL_SHIFT))
slew = 0;
}
priv->clkout |= (slew << CLKOUT_SL_SHIFT) &
CLKOUT_SL_MASK;
} else {
dev_dbg(&pdev->dev, "invalid clock-out-frequency\n");
}
}
return 0;
}
static int cc770_get_platform_data(struct platform_device *pdev,
struct cc770_priv *priv)
{
struct cc770_platform_data *pdata = dev_get_platdata(&pdev->dev);
priv->can.clock.freq = pdata->osc_freq;
if (priv->cpu_interface & CPUIF_DSC)
priv->can.clock.freq /= 2;
priv->clkout = pdata->cor;
priv->bus_config = pdata->bcr;
priv->cpu_interface = pdata->cir;
return 0;
}
static int cc770_platform_probe(struct platform_device *pdev)
{
struct net_device *dev;
struct cc770_priv *priv;
struct resource *mem;
resource_size_t mem_size;
void __iomem *base;
int err, irq;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
irq = platform_get_irq(pdev, 0);
if (!mem || irq <= 0)
return -ENODEV;
mem_size = resource_size(mem);
if (!request_mem_region(mem->start, mem_size, pdev->name))
return -EBUSY;
base = ioremap(mem->start, mem_size);
if (!base) {
err = -ENOMEM;
goto exit_release_mem;
}
dev = alloc_cc770dev(0);
if (!dev) {
err = -ENOMEM;
goto exit_unmap_mem;
}
dev->irq = irq;
priv = netdev_priv(dev);
priv->read_reg = cc770_platform_read_reg;
priv->write_reg = cc770_platform_write_reg;
priv->irq_flags = IRQF_SHARED;
priv->reg_base = base;
if (pdev->dev.of_node)
err = cc770_get_of_node_data(pdev, priv);
else if (dev_get_platdata(&pdev->dev))
err = cc770_get_platform_data(pdev, priv);
else
err = -ENODEV;
if (err)
goto exit_free_cc770;
dev_dbg(&pdev->dev,
"reg_base=0x%p irq=%d clock=%d cpu_interface=0x%02x "
"bus_config=0x%02x clkout=0x%02x\n",
priv->reg_base, dev->irq, priv->can.clock.freq,
priv->cpu_interface, priv->bus_config, priv->clkout);
platform_set_drvdata(pdev, dev);
SET_NETDEV_DEV(dev, &pdev->dev);
err = register_cc770dev(dev);
if (err) {
dev_err(&pdev->dev,
"couldn't register CC700 device (err=%d)\n", err);
goto exit_free_cc770;
}
return 0;
exit_free_cc770:
free_cc770dev(dev);
exit_unmap_mem:
iounmap(base);
exit_release_mem:
release_mem_region(mem->start, mem_size);
return err;
}
static void cc770_platform_remove(struct platform_device *pdev)
{
struct net_device *dev = platform_get_drvdata(pdev);
struct cc770_priv *priv = netdev_priv(dev);
struct resource *mem;
unregister_cc770dev(dev);
iounmap(priv->reg_base);
free_cc770dev(dev);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(mem->start, resource_size(mem));
}
static const struct of_device_id cc770_platform_table[] = {
{.compatible = "bosch,cc770"}, /* CC770 from Bosch */
{.compatible = "intc,82527"}, /* AN82527 from Intel CP */
{},
};
MODULE_DEVICE_TABLE(of, cc770_platform_table);
static struct platform_driver cc770_platform_driver = {
.driver = {
.name = DRV_NAME,
.of_match_table = cc770_platform_table,
},
.probe = cc770_platform_probe,
.remove = cc770_platform_remove,
};
module_platform_driver(cc770_platform_driver);
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