/*
* 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, see <http://www.gnu.org/licenses/>.
*/
#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);
void (*put_clock)(struct platform_device *ofdev);
};
#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
static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
const char *clock_source, int *mscan_clksrc)
{
struct device_node *np;
u32 clockdiv;
enum {
CLK_FROM_AUTO,
CLK_FROM_IPS,
CLK_FROM_SYS,
CLK_FROM_REF,
} clk_from;
struct clk *clk_in, *clk_can;
unsigned long freq_calc;
struct mscan_priv *priv;
struct clk *clk_ipg;
/* the caller passed in the clock source spec that was read from
* the device tree, get the optional clock divider as well
*/
np = ofdev->dev.of_node;
clockdiv = 1;
of_property_read_u32(np, "fsl,mscan-clock-divider", &clockdiv);
dev_dbg(&ofdev->dev, "device tree specs: clk src[%s] div[%d]\n",
clock_source ? clock_source : "<NULL>", clockdiv);
/* when clock-source is 'ip', the CANCTL1[CLKSRC] bit needs to
* get set, and the 'ips' clock is the input to the MSCAN
* component
*
* for clock-source values of 'ref' or 'sys' the CANCTL1[CLKSRC]
* bit needs to get cleared, an optional clock-divider may have
* been specified (the default value is 1), the appropriate
* MSCAN related MCLK is the input to the MSCAN component
*
* in the absence of a clock-source spec, first an optimal clock
* gets determined based on the 'sys' clock, if that fails the
* 'ref' clock is used
*/
clk_from = CLK_FROM_AUTO;
if (clock_source) {
/* interpret the device tree's spec for the clock source */
if (!strcmp(clock_source, "ip"))
clk_from = CLK_FROM_IPS;
else if (!strcmp(clock_source, "sys"))
clk_from = CLK_FROM_SYS;
else if (!strcmp(clock_source, "ref"))
clk_from = CLK_FROM_REF;
else
goto err_invalid;
dev_dbg(&ofdev->dev, "got a clk source spec[%d]\n", clk_from);
}
if (clk_from == CLK_FROM_AUTO) {
/* no spec so far, try the 'sys' clock; round to the
* next MHz and see if we can get a multiple of 16MHz
*/
dev_dbg(&ofdev->dev, "no clk source spec, trying SYS\n");
clk_in = devm_clk_get(&ofdev->dev, "sys");
if (IS_ERR(clk_in))
goto err_notavail;
freq_calc = clk_get_rate(clk_in);
freq_calc += 499999;
freq_calc /= 1000000;
freq_calc *= 1000000;
if ((freq_calc % 16000000) == 0) {
clk_from = CLK_FROM_SYS;
clockdiv = freq_calc / 16000000;
dev_dbg(&ofdev->dev,
"clk fit, sys[%lu] div[%d] freq[%lu]\n",
freq_calc, clockdiv, freq_calc / clockdiv);
}
}
if (clk_from == CLK_FROM_AUTO) {
/* no spec so far, use the 'ref' clock */
dev_dbg(&ofdev->dev, "no clk source spec, trying REF\n");
clk_in = devm_clk_get(&ofdev->dev, "ref");
if (IS_ERR(clk_in))
goto err_notavail;
clk_from = CLK_FROM_REF;
freq_calc = clk_get_rate(clk_in);
dev_dbg(&ofdev->dev,
"clk fit, ref[%lu] (no div) freq[%lu]\n",
freq_calc, freq_calc);
}
/* select IPS or MCLK as the MSCAN input (returned to the caller),
* setup the MCLK mux source and rate if applicable, apply the
* optionally specified or derived above divider, and determine
* the actual resulting clock rate to return to the caller
*/
switch (clk_from) {
case CLK_FROM_IPS:
clk_can = devm_clk_get(&ofdev->dev, "ips");
if (IS_ERR(clk_can))
goto err_notavail;
priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
priv->clk_can = clk_can;
freq_calc = clk_get_rate(clk_can);
*mscan_clksrc = MSCAN_CLKSRC_IPS;
dev_dbg(&ofdev->dev, "clk from IPS, clksrc[%d] freq[%lu]\n",
*mscan_clksrc, freq_calc);
break;
case CLK_FROM_SYS:
case CLK_FROM_REF:
clk_can = devm_clk_get(&ofdev->dev, "mclk");
if (IS_ERR(clk_can))
goto err_notavail;
priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
priv->clk_can = clk_can;
if (clk_from == CLK_FROM_SYS)
clk_in = devm_clk_get(&ofdev->dev, "sys");
if (clk_from == CLK_FROM_REF)
clk_in = devm_clk_get(&ofdev->dev, "ref");
if (IS_ERR(clk_in))
goto err_notavail;
clk_set_parent(clk_can, clk_in);
freq_calc = clk_get_rate(clk_in);
freq_calc /= clockdiv;
clk_set_rate(clk_can, freq_calc);
freq_calc = clk_get_rate(clk_can);
*mscan_clksrc = MSCAN_CLKSRC_BUS;
dev_dbg(&ofdev->dev, "clk from MCLK, clksrc[%d] freq[%lu]\n",
*mscan_clksrc, freq_calc);
break;
default:
goto err_invalid;
}
/* the above clk_can item is used for the bitrate, access to
* the peripheral's register set needs the clk_ipg item
*/
clk_ipg = devm_clk_get(&ofdev->dev, "ipg");
if (IS_ERR(clk_ipg))
goto err_notavail_ipg;
if (clk_prepare_enable(clk_ipg))
goto err_notavail_ipg;
priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
priv->clk_ipg = clk_ipg;
/* return the determined clock source rate */
return freq_calc;
err_invalid:
dev_err(&ofdev->dev, "invalid clock source specification\n");
/* clock source rate could not get determined */
return 0;
err_notavail:
dev_err(&ofdev->dev, "cannot acquire or setup bitrate clock source\n");
/* clock source rate could not get determined */
return 0;
err_notavail_ipg:
dev_err(&ofdev->dev, "cannot acquire or setup register clock\n");
/* clock source rate could not get determined */
return 0;
}
static void mpc512x_can_put_clock(struct platform_device *ofdev)
{
struct mscan_priv *priv;
priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
if (priv->clk_ipg)
clk_disable_unprepare(priv->clk_ipg);
}
#else /* !CONFIG_PPC_MPC512x */
static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
const char *clock_name, int *mscan_clksrc)
{
return 0;
}
#define mpc512x_can_put_clock NULL
#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;
platform_set_drvdata(ofdev, dev);
SET_NETDEV_DEV(dev, &ofdev->dev);
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;
}
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_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)
{
const struct of_device_id *match;
const struct mpc5xxx_can_data *data;
struct net_device *dev = platform_get_drvdata(ofdev);
struct mscan_priv *priv = netdev_priv(dev);
match = of_match_device(mpc5xxx_can_table, &ofdev->dev);
data = match ? match->data : NULL;
unregister_mscandev(dev);
if (data && data->put_clock)
data->put_clock(ofdev);
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 = platform_get_drvdata(ofdev);
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 = platform_get_drvdata(ofdev);
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,
/* .put_clock not applicable */
};
static const struct mpc5xxx_can_data mpc5121_can_data = {
.type = MSCAN_TYPE_MPC5121,
.get_clock = mpc512x_can_get_clock,
.put_clock = mpc512x_can_put_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");