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* CAN bus driver for the Freescale MPC5xxx embedded CPU.
*
* Copyright (C) 2004-2005 Andrey Volkov <avolkov@varma-el.com>,
* Varma Electronics Oy
* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
* Copyright (C) 2009 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the version 2 of the GNU General Public License
* as published by the Free Software Foundation
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/netdevice.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/of_platform.h>
#include <sysdev/fsl_soc.h>
#include <linux/io.h>
#include <asm/mpc52xx.h>
#include "mscan.h"
#define DRV_NAME "mpc5xxx_can"
static struct of_device_id mpc52xx_cdm_ids[] __devinitdata = {
{ .compatible = "fsl,mpc5200-cdm", },
{}
};
/*
* Get frequency of the MSCAN clock source
*
* Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock (IP_CLK)
* can be selected. According to the MPC5200 user's manual, the oscillator
* clock is the better choice as it has less jitter but due to a hardware
* bug, it can not be selected for the old MPC5200 Rev. A chips.
*/
static unsigned int __devinit mpc52xx_can_clock_freq(struct of_device *of,
int clock_src)
{
unsigned int pvr;
struct mpc52xx_cdm __iomem *cdm;
struct device_node *np_cdm;
unsigned int freq;
u32 val;
pvr = mfspr(SPRN_PVR);
freq = mpc5xxx_get_bus_frequency(of->node);
if (!freq)
return 0;
if (clock_src == MSCAN_CLKSRC_BUS || pvr == 0x80822011)
return freq;
/* Determine SYS_XTAL_IN frequency from the clock domain settings */
np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids);
if (!np_cdm) {
dev_err(&of->dev, "can't get clock node!\n");
return 0;
}
cdm = of_iomap(np_cdm, 0);
of_node_put(np_cdm);
if (in_8(&cdm->ipb_clk_sel) & 0x1)
freq *= 2;
val = in_be32(&cdm->rstcfg);
freq *= (val & (1 << 5)) ? 8 : 4;
freq /= (val & (1 << 6)) ? 12 : 16;
iounmap(cdm);
return freq;
}
static int __devinit mpc5xxx_can_probe(struct of_device *ofdev,
const struct of_device_id *id)
{
struct device_node *np = ofdev->node;
struct net_device *dev;
struct mscan_priv *priv;
void __iomem *base;
const char *clk_src;
int err, irq, clock_src;
base = of_iomap(ofdev->node, 0);
if (!base) {
dev_err(&ofdev->dev, "couldn't ioremap\n");
err = -ENOMEM;
goto exit_release_mem;
}
irq = irq_of_parse_and_map(np, 0);
if (!irq) {
dev_err(&ofdev->dev, "no irq found\n");
err = -ENODEV;
goto exit_unmap_mem;
}
dev = alloc_mscandev();
if (!dev) {
err = -ENOMEM;
goto exit_dispose_irq;
}
priv = netdev_priv(dev);
priv->reg_base = base;
dev->irq = irq;
/*
* Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock
* (IP_CLK) can be selected as MSCAN clock source. According to
* the MPC5200 user's manual, the oscillator clock is the better
* choice as it has less jitter. For this reason, it is selected
* by default.
*/
clk_src = of_get_property(np, "fsl,mscan-clock-source", NULL);
if (clk_src && strcmp(clk_src, "ip") == 0)
clock_src = MSCAN_CLKSRC_BUS;
else
clock_src = MSCAN_CLKSRC_XTAL;
priv->can.clock.freq = mpc52xx_can_clock_freq(ofdev, clock_src);
if (!priv->can.clock.freq) {
dev_err(&ofdev->dev, "couldn't get MSCAN clock frequency\n");
err = -ENODEV;
goto exit_free_mscan;
}
SET_NETDEV_DEV(dev, &ofdev->dev);
err = register_mscandev(dev, clock_src);
if (err) {
dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
DRV_NAME, err);
goto exit_free_mscan;
}
dev_set_drvdata(&ofdev->dev, dev);
dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n",
priv->reg_base, dev->irq, priv->can.clock.freq);
return 0;
exit_free_mscan:
free_candev(dev);
exit_dispose_irq:
irq_dispose_mapping(irq);
exit_unmap_mem:
iounmap(base);
exit_release_mem:
return err;
}
static int __devexit mpc5xxx_can_remove(struct of_device *ofdev)
{
struct net_device *dev = dev_get_drvdata(&ofdev->dev);
struct mscan_priv *priv = netdev_priv(dev);
dev_set_drvdata(&ofdev->dev, NULL);
unregister_mscandev(dev);
iounmap(priv->reg_base);
irq_dispose_mapping(dev->irq);
free_candev(dev);
return 0;
}
#ifdef CONFIG_PM
static struct mscan_regs saved_regs;
static int mpc5xxx_can_suspend(struct of_device *ofdev, pm_message_t state)
{
struct net_device *dev = dev_get_drvdata(&ofdev->dev);
struct mscan_priv *priv = netdev_priv(dev);
struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
_memcpy_fromio(&saved_regs, regs, sizeof(*regs));
return 0;
}
static int mpc5xxx_can_resume(struct of_device *ofdev)
{
struct net_device *dev = dev_get_drvdata(&ofdev->dev);
struct mscan_priv *priv = netdev_priv(dev);
struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
regs->canctl0 |= MSCAN_INITRQ;
while (!(regs->canctl1 & MSCAN_INITAK))
udelay(10);
regs->canctl1 = saved_regs.canctl1;
regs->canbtr0 = saved_regs.canbtr0;
regs->canbtr1 = saved_regs.canbtr1;
regs->canidac = saved_regs.canidac;
/* restore masks, buffers etc. */
_memcpy_toio(®s->canidar1_0, (void *)&saved_regs.canidar1_0,
sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0));
regs->canctl0 &= ~MSCAN_INITRQ;
regs->cantbsel = saved_regs.cantbsel;
regs->canrier = saved_regs.canrier;
regs->cantier = saved_regs.cantier;
regs->canctl0 = saved_regs.canctl0;
return 0;
}
#endif
static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
{.compatible = "fsl,mpc5200-mscan"},
{},
};
static struct of_platform_driver mpc5xxx_can_driver = {
.owner = THIS_MODULE,
.name = "mpc5xxx_can",
.probe = mpc5xxx_can_probe,
.remove = __devexit_p(mpc5xxx_can_remove),
#ifdef CONFIG_PM
.suspend = mpc5xxx_can_suspend,
.resume = mpc5xxx_can_resume,
#endif
.match_table = mpc5xxx_can_table,
};
static int __init mpc5xxx_can_init(void)
{
return of_register_platform_driver(&mpc5xxx_can_driver);
}
module_init(mpc5xxx_can_init);
static void __exit mpc5xxx_can_exit(void)
{
return of_unregister_platform_driver(&mpc5xxx_can_driver);
};
module_exit(mpc5xxx_can_exit);
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_DESCRIPTION("Freescale MPC5200 CAN driver");
MODULE_LICENSE("GPL v2");
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