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/*
* Platform CAN bus driver for Bosch C_CAN controller
*
* Copyright (C) 2010 ST Microelectronics
* Bhupesh Sharma <bhupesh.sharma@st.com>
*
* Borrowed heavily from the C_CAN driver originally written by:
* Copyright (C) 2007
* - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de>
* - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch>
*
* Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A and B.
* Bosch C_CAN user manual can be obtained from:
* http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/
* users_manual_c_can.pdf
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/list.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/can/dev.h>
#include "c_can.h"
/*
* 16-bit c_can registers can be arranged differently in the memory
* architecture of different implementations. For example: 16-bit
* 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,
void *reg)
{
return readw(reg);
}
static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
void *reg, u16 val)
{
writew(val, reg);
}
static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
void *reg)
{
return readw(reg + (long)reg - (long)priv->regs);
}
static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
void *reg, u16 val)
{
writew(val, reg + (long)reg - (long)priv->regs);
}
static int __devinit c_can_plat_probe(struct platform_device *pdev)
{
int ret;
void __iomem *addr;
struct net_device *dev;
struct c_can_priv *priv;
struct resource *mem;
int irq;
#ifdef CONFIG_HAVE_CLK
struct clk *clk;
/* get the appropriate clk */
clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(clk)) {
dev_err(&pdev->dev, "no clock defined\n");
ret = -ENODEV;
goto exit;
}
#endif
/* get the platform data */
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
irq = platform_get_irq(pdev, 0);
if (!mem || irq <= 0) {
ret = -ENODEV;
goto exit_free_clk;
}
if (!request_mem_region(mem->start, resource_size(mem),
KBUILD_MODNAME)) {
dev_err(&pdev->dev, "resource unavailable\n");
ret = -ENODEV;
goto exit_free_clk;
}
addr = ioremap(mem->start, resource_size(mem));
if (!addr) {
dev_err(&pdev->dev, "failed to map can port\n");
ret = -ENOMEM;
goto exit_release_mem;
}
/* allocate the c_can device */
dev = alloc_c_can_dev();
if (!dev) {
ret = -ENOMEM;
goto exit_iounmap;
}
priv = netdev_priv(dev);
dev->irq = irq;
priv->regs = addr;
#ifdef CONFIG_HAVE_CLK
priv->can.clock.freq = clk_get_rate(clk);
priv->priv = clk;
#endif
switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
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;
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;
break;
}
platform_set_drvdata(pdev, dev);
SET_NETDEV_DEV(dev, &pdev->dev);
ret = register_c_can_dev(dev);
if (ret) {
dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
KBUILD_MODNAME, ret);
goto exit_free_device;
}
dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
KBUILD_MODNAME, priv->regs, dev->irq);
return 0;
exit_free_device:
platform_set_drvdata(pdev, NULL);
free_c_can_dev(dev);
exit_iounmap:
iounmap(addr);
exit_release_mem:
release_mem_region(mem->start, resource_size(mem));
exit_free_clk:
#ifdef CONFIG_HAVE_CLK
clk_put(clk);
exit:
#endif
dev_err(&pdev->dev, "probe failed\n");
return ret;
}
static int __devexit c_can_plat_remove(struct platform_device *pdev)
{
struct net_device *dev = platform_get_drvdata(pdev);
struct c_can_priv *priv = netdev_priv(dev);
struct resource *mem;
unregister_c_can_dev(dev);
platform_set_drvdata(pdev, NULL);
free_c_can_dev(dev);
iounmap(priv->regs);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(mem->start, resource_size(mem));
#ifdef CONFIG_HAVE_CLK
clk_put(priv->priv);
#endif
return 0;
}
static struct platform_driver c_can_plat_driver = {
.driver = {
.name = KBUILD_MODNAME,
.owner = THIS_MODULE,
},
.probe = c_can_plat_probe,
.remove = __devexit_p(c_can_plat_remove),
};
static int __init c_can_plat_init(void)
{
return platform_driver_register(&c_can_plat_driver);
}
module_init(c_can_plat_init);
static void __exit c_can_plat_exit(void)
{
platform_driver_unregister(&c_can_plat_driver);
}
module_exit(c_can_plat_exit);
MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");
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