- 根目录:
- drivers
- net
- can
- mscan
- mpc5xxx_can.c
/*
* 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/dev.h>
#include <linux/of_platform.h>
#include <sysdev/fsl_soc.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <asm/mpc52xx.h>
#include "mscan.h"
#define DRV_NAME "mpc5xxx_can"
struct mpc5xxx_can_data {
unsigned int type;
u32 (*get_clock)(struct platform_device *ofdev, const char *clock_name,
int *mscan_clksrc);
};
#ifdef CONFIG_PPC_MPC52xx
static struct of_device_id mpc52xx_cdm_ids[] = {
{ .compatible = "fsl,mpc5200-cdm", },
{}
};
static u32 mpc52xx_can_get_clock(struct platform_device *ofdev,
const char *clock_name, int *mscan_clksrc)
{
unsigned int pvr;
struct mpc52xx_cdm __iomem *cdm;
struct device_node *np_cdm;
unsigned int freq;
u32 val;
pvr = mfspr(SPRN_PVR);
/*
* 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. Unfortunately, it can not be selected for the old
* MPC5200 Rev. A chips due to a hardware bug (check errata).
*/
if (clock_name && strcmp(clock_name, "ip") == 0)
*mscan_clksrc = MSCAN_CLKSRC_BUS;
else
*mscan_clksrc = MSCAN_CLKSRC_XTAL;
freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
if (!freq)
return 0;
if (*mscan_clksrc == 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(&ofdev->dev, "can't get clock node!\n");
return 0;
}
cdm = of_iomap(np_cdm, 0);
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;
of_node_put(np_cdm);
iounmap(cdm);
return freq;
}
#else /* !CONFIG_PPC_MPC52xx */
static u32 mpc52xx_can_get_clock(struct platform_device *ofdev,
const char *clock_name, int *mscan_clksrc)
{
return 0;
}
#endif /* CONFIG_PPC_MPC52xx */
#ifdef CONFIG_PPC_MPC512x
struct mpc512x_clockctl {
u32 spmr; /* System PLL Mode Reg */
u32 sccr[2]; /* System Clk Ctrl Reg 1 & 2 */
u32 scfr1; /* System Clk Freq Reg 1 */
u32 scfr2; /* System Clk Freq Reg 2 */
u32 reserved;
u32 bcr; /* Bread Crumb Reg */
u32 pccr[12]; /* PSC Clk Ctrl Reg 0-11 */
u32 spccr; /* SPDIF Clk Ctrl Reg */
u32 cccr; /* CFM Clk Ctrl Reg */
u32 dccr; /* DIU Clk Cnfg Reg */
u32 mccr[4]; /* MSCAN Clk Ctrl Reg 1-3 */
};
static struct of_device_id mpc512x_clock_ids[] = {
{ .compatible = "fsl,mpc5121-clock", },
{}
};
static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
const char *clock_name, int *mscan_clksrc)
{
struct mpc512x_clockctl __iomem *clockctl;
struct device_node *np_clock;
struct clk *sys_clk, *ref_clk;
int plen, clockidx, clocksrc = -1;
u32 sys_freq, val, clockdiv = 1, freq = 0;
const u32 *pval;
np_clock = of_find_matching_node(NULL, mpc512x_clock_ids);
if (!np_clock) {
dev_err(&ofdev->dev, "couldn't find clock node\n");
return 0;
}
clockctl = of_iomap(np_clock, 0);
if (!clockctl) {
dev_err(&ofdev->dev, "couldn't map clock registers\n");
goto exit_put;
}
/* Determine the MSCAN device index from the physical address */
pval = of_get_property(ofdev->dev.of_node, "reg", &plen);
BUG_ON(!pval || plen < sizeof(*pval));
clockidx = (*pval & 0x80) ? 1 : 0;
if (*pval & 0x2000)
clockidx += 2;
/*
* Clock source and divider selection: 3 different clock sources
* can be selected: "ip", "ref" or "sys". For the latter two, a
* clock divider can be defined as well. If the clock source is
* not specified by the device tree, we first try to find an
* optimal CAN source clock based on the system clock. If that
* is not posslible, the reference clock will be used.
*/
if (clock_name && !strcmp(clock_name, "ip")) {
*mscan_clksrc = MSCAN_CLKSRC_IPS;
freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
} else {
*mscan_clksrc = MSCAN_CLKSRC_BUS;
pval = of_get_property(ofdev->dev.of_node,
"fsl,mscan-clock-divider", &plen);
if (pval && plen == sizeof(*pval))
clockdiv = *pval;
if (!clockdiv)
clockdiv = 1;
if (!clock_name || !strcmp(clock_name, "sys")) {
sys_clk = clk_get(&ofdev->dev, "sys_clk");
if (IS_ERR(sys_clk)) {
dev_err(&ofdev->dev, "couldn't get sys_clk\n");
goto exit_unmap;
}
/* Get and round up/down sys clock rate */
sys_freq = 1000000 *
((clk_get_rate(sys_clk) + 499999) / 1000000);
if (!clock_name) {
/* A multiple of 16 MHz would be optimal */
if ((sys_freq % 16000000) == 0) {
clocksrc = 0;
clockdiv = sys_freq / 16000000;
freq = sys_freq / clockdiv;
}
} else {
clocksrc = 0;
freq = sys_freq / clockdiv;
}
}
if (clocksrc < 0) {
ref_clk = clk_get(&ofdev->dev, "ref_clk");
if (IS_ERR(ref_clk)) {
dev_err(&ofdev->dev, "couldn't get ref_clk\n");
goto exit_unmap;
}
clocksrc = 1;
freq = clk_get_rate(ref_clk) / clockdiv;
}
}
/* Disable clock */
out_be32(&clockctl->mccr[clockidx], 0x0);
if (clocksrc >= 0) {
/* Set source and divider */
val = (clocksrc << 14) | ((clockdiv - 1) << 17);
out_be32(&clockctl->mccr[clockidx], val);
/* Enable clock */
out_be32(&clockctl->mccr[clockidx], val | 0x10000);
}
/* Enable MSCAN clock domain */
val = in_be32(&clockctl->sccr[1]);
if (!(val & (1 << 25)))
out_be32(&clockctl->sccr[1], val | (1 << 25));
dev_dbg(&ofdev->dev, "using '%s' with frequency divider %d\n",
*mscan_clksrc == MSCAN_CLKSRC_IPS ? "ips_clk" :
clocksrc == 1 ? "ref_clk" : "sys_clk", clockdiv);
exit_unmap:
iounmap(clockctl);
exit_put:
of_node_put(np_clock);
return freq;
}
#else /* !CONFIG_PPC_MPC512x */
static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
const char *clock_name, int *mscan_clksrc)
{
return 0;
}
#endif /* CONFIG_PPC_MPC512x */
static const struct of_device_id mpc5xxx_can_table[];
static int mpc5xxx_can_probe(struct platform_device *ofdev)
{
const struct of_device_id *match;
const struct mpc5xxx_can_data *data;
struct device_node *np = ofdev->dev.of_node;
struct net_device *dev;
struct mscan_priv *priv;
void __iomem *base;
const char *clock_name = NULL;
int irq, mscan_clksrc = 0;
int err = -ENOMEM;
match = of_match_device(mpc5xxx_can_table, &ofdev->dev);
if (!match)
return -EINVAL;
data = match->data;
base = of_iomap(np, 0);
if (!base) {
dev_err(&ofdev->dev, "couldn't ioremap\n");
return err;
}
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)
goto exit_dispose_irq;
priv = netdev_priv(dev);
priv->reg_base = base;
dev->irq = irq;
clock_name = of_get_property(np, "fsl,mscan-clock-source", NULL);
BUG_ON(!data);
priv->type = data->type;
priv->can.clock.freq = data->get_clock(ofdev, clock_name,
&mscan_clksrc);
if (!priv->can.clock.freq) {
dev_err(&ofdev->dev, "couldn't get MSCAN clock properties\n");
goto exit_free_mscan;
}
SET_NETDEV_DEV(dev, &ofdev->dev);
err = register_mscandev(dev, mscan_clksrc);
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);
return err;
}
static int mpc5xxx_can_remove(struct platform_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 platform_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 platform_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 const struct mpc5xxx_can_data mpc5200_can_data = {
.type = MSCAN_TYPE_MPC5200,
.get_clock = mpc52xx_can_get_clock,
};
static const struct mpc5xxx_can_data mpc5121_can_data = {
.type = MSCAN_TYPE_MPC5121,
.get_clock = mpc512x_can_get_clock,
};
static const struct of_device_id mpc5xxx_can_table[] = {
{ .compatible = "fsl,mpc5200-mscan", .data = &mpc5200_can_data, },
/* Note that only MPC5121 Rev. 2 (and later) is supported */
{ .compatible = "fsl,mpc5121-mscan", .data = &mpc5121_can_data, },
{},
};
MODULE_DEVICE_TABLE(of, mpc5xxx_can_table);
static struct platform_driver mpc5xxx_can_driver = {
.driver = {
.name = "mpc5xxx_can",
.owner = THIS_MODULE,
.of_match_table = mpc5xxx_can_table,
},
.probe = mpc5xxx_can_probe,
.remove = mpc5xxx_can_remove,
#ifdef CONFIG_PM
.suspend = mpc5xxx_can_suspend,
.resume = mpc5xxx_can_resume,
#endif
};
module_platform_driver(mpc5xxx_can_driver);
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_DESCRIPTION("Freescale MPC5xxx CAN driver");
MODULE_LICENSE("GPL v2");