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linuxdebug/arch/powerpc/platforms/52xx/mpc52xx_common.c

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/*
*
* Utility functions for the Freescale MPC52xx.
*
* Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com>
*
* 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.
*
*/
#undef DEBUG
#include <linux/gpio.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/export.h>
#include <asm/io.h>
#include <asm/mpc52xx.h>
/* MPC5200 device tree match tables */
static const struct of_device_id mpc52xx_xlb_ids[] __initconst = {
{ .compatible = "fsl,mpc5200-xlb", },
{ .compatible = "mpc5200-xlb", },
{}
};
static const struct of_device_id mpc52xx_bus_ids[] __initconst = {
{ .compatible = "fsl,mpc5200-immr", },
{ .compatible = "fsl,mpc5200b-immr", },
{ .compatible = "simple-bus", },
/* depreciated matches; shouldn't be used in new device trees */
{ .compatible = "fsl,lpb", },
{ .type = "builtin", .compatible = "mpc5200", }, /* efika */
{ .type = "soc", .compatible = "mpc5200", }, /* lite5200 */
{}
};
/*
* This variable is mapped in mpc52xx_map_wdt() and used in mpc52xx_restart().
* Permanent mapping is required because mpc52xx_restart() can be called
* from interrupt context while node mapping (which calls ioremap())
* cannot be used at such point.
*/
static DEFINE_SPINLOCK(mpc52xx_lock);
static struct mpc52xx_gpt __iomem *mpc52xx_wdt;
static struct mpc52xx_cdm __iomem *mpc52xx_cdm;
/*
* Configure the XLB arbiter settings to match what Linux expects.
*/
void __init
mpc5200_setup_xlb_arbiter(void)
{
struct device_node *np;
struct mpc52xx_xlb __iomem *xlb;
np = of_find_matching_node(NULL, mpc52xx_xlb_ids);
xlb = of_iomap(np, 0);
of_node_put(np);
if (!xlb) {
printk(KERN_ERR __FILE__ ": "
"Error mapping XLB in mpc52xx_setup_cpu(). "
"Expect some abnormal behavior\n");
return;
}
/* Configure the XLB Arbiter priorities */
out_be32(&xlb->master_pri_enable, 0xff);
out_be32(&xlb->master_priority, 0x11111111);
/*
* Disable XLB pipelining
* (cfr errate 292. We could do this only just before ATA PIO
* transaction and re-enable it afterwards ...)
* Not needed on MPC5200B.
*/
if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR)
out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
iounmap(xlb);
}
/*
* This variable is mapped in mpc52xx_map_common_devices and
* used in mpc5200_psc_ac97_gpio_reset().
*/
static DEFINE_SPINLOCK(gpio_lock);
struct mpc52xx_gpio __iomem *simple_gpio;
struct mpc52xx_gpio_wkup __iomem *wkup_gpio;
/**
* mpc52xx_declare_of_platform_devices: register internal devices and children
* of the localplus bus to the of_platform
* bus.
*/
void __init mpc52xx_declare_of_platform_devices(void)
{
/* Find all the 'platform' devices and register them. */
if (of_platform_populate(NULL, mpc52xx_bus_ids, NULL, NULL))
pr_err(__FILE__ ": Error while populating devices from DT\n");
}
/*
* match tables used by mpc52xx_map_common_devices()
*/
static const struct of_device_id mpc52xx_gpt_ids[] __initconst = {
{ .compatible = "fsl,mpc5200-gpt", },
{ .compatible = "mpc5200-gpt", }, /* old */
{}
};
static const struct of_device_id mpc52xx_cdm_ids[] __initconst = {
{ .compatible = "fsl,mpc5200-cdm", },
{ .compatible = "mpc5200-cdm", }, /* old */
{}
};
static const struct of_device_id mpc52xx_gpio_simple[] __initconst = {
{ .compatible = "fsl,mpc5200-gpio", },
{}
};
static const struct of_device_id mpc52xx_gpio_wkup[] __initconst = {
{ .compatible = "fsl,mpc5200-gpio-wkup", },
{}
};
/**
* mpc52xx_map_common_devices: iomap devices required by common code
*/
void __init
mpc52xx_map_common_devices(void)
{
struct device_node *np;
/* mpc52xx_wdt is mapped here and used in mpc52xx_restart,
* possibly from a interrupt context. wdt is only implement
* on a gpt0, so check has-wdt property before mapping.
*/
for_each_matching_node(np, mpc52xx_gpt_ids) {
if (of_get_property(np, "fsl,has-wdt", NULL) ||
of_get_property(np, "has-wdt", NULL)) {
mpc52xx_wdt = of_iomap(np, 0);
of_node_put(np);
break;
}
}
/* Clock Distribution Module, used by PSC clock setting function */
np = of_find_matching_node(NULL, mpc52xx_cdm_ids);
mpc52xx_cdm = of_iomap(np, 0);
of_node_put(np);
/* simple_gpio registers */
np = of_find_matching_node(NULL, mpc52xx_gpio_simple);
simple_gpio = of_iomap(np, 0);
of_node_put(np);
/* wkup_gpio registers */
np = of_find_matching_node(NULL, mpc52xx_gpio_wkup);
wkup_gpio = of_iomap(np, 0);
of_node_put(np);
}
/**
* mpc52xx_set_psc_clkdiv: Set clock divider in the CDM for PSC ports
*
* @psc_id: id of psc port; must be 1,2,3 or 6
* @clkdiv: clock divider value to put into CDM PSC register.
*/
int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv)
{
unsigned long flags;
u16 __iomem *reg;
u32 val;
u32 mask;
u32 mclken_div;
if (!mpc52xx_cdm)
return -ENODEV;
mclken_div = 0x8000 | (clkdiv & 0x1FF);
switch (psc_id) {
case 1: reg = &mpc52xx_cdm->mclken_div_psc1; mask = 0x20; break;
case 2: reg = &mpc52xx_cdm->mclken_div_psc2; mask = 0x40; break;
case 3: reg = &mpc52xx_cdm->mclken_div_psc3; mask = 0x80; break;
case 6: reg = &mpc52xx_cdm->mclken_div_psc6; mask = 0x10; break;
default:
return -ENODEV;
}
/* Set the rate and enable the clock */
spin_lock_irqsave(&mpc52xx_lock, flags);
out_be16(reg, mclken_div);
val = in_be32(&mpc52xx_cdm->clk_enables);
out_be32(&mpc52xx_cdm->clk_enables, val | mask);
spin_unlock_irqrestore(&mpc52xx_lock, flags);
return 0;
}
EXPORT_SYMBOL(mpc52xx_set_psc_clkdiv);
/**
* mpc52xx_restart: ppc_md->restart hook for mpc5200 using the watchdog timer
*/
void __noreturn mpc52xx_restart(char *cmd)
{
local_irq_disable();
/* Turn on the watchdog and wait for it to expire.
* It effectively does a reset. */
if (mpc52xx_wdt) {
out_be32(&mpc52xx_wdt->mode, 0x00000000);
out_be32(&mpc52xx_wdt->count, 0x000000ff);
out_be32(&mpc52xx_wdt->mode, 0x00009004);
} else
printk(KERN_ERR __FILE__ ": "
"mpc52xx_restart: Can't access wdt. "
"Restart impossible, system halted.\n");
while (1);
}
#define PSC1_RESET 0x1
#define PSC1_SYNC 0x4
#define PSC1_SDATA_OUT 0x1
#define PSC2_RESET 0x2
#define PSC2_SYNC (0x4<<4)
#define PSC2_SDATA_OUT (0x1<<4)
#define MPC52xx_GPIO_PSC1_MASK 0x7
#define MPC52xx_GPIO_PSC2_MASK (0x7<<4)
/**
* mpc5200_psc_ac97_gpio_reset: Use gpio pins to reset the ac97 bus
*
* @psc: psc number to reset (only psc 1 and 2 support ac97)
*/
int mpc5200_psc_ac97_gpio_reset(int psc_number)
{
unsigned long flags;
u32 gpio;
u32 mux;
int out;
int reset;
int sync;
if ((!simple_gpio) || (!wkup_gpio))
return -ENODEV;
switch (psc_number) {
case 0:
reset = PSC1_RESET; /* AC97_1_RES */
sync = PSC1_SYNC; /* AC97_1_SYNC */
out = PSC1_SDATA_OUT; /* AC97_1_SDATA_OUT */
gpio = MPC52xx_GPIO_PSC1_MASK;
break;
case 1:
reset = PSC2_RESET; /* AC97_2_RES */
sync = PSC2_SYNC; /* AC97_2_SYNC */
out = PSC2_SDATA_OUT; /* AC97_2_SDATA_OUT */
gpio = MPC52xx_GPIO_PSC2_MASK;
break;
default:
pr_err(__FILE__ ": Unable to determine PSC, no ac97 "
"cold-reset will be performed\n");
return -ENODEV;
}
spin_lock_irqsave(&gpio_lock, flags);
/* Reconfigure pin-muxing to gpio */
mux = in_be32(&simple_gpio->port_config);
out_be32(&simple_gpio->port_config, mux & (~gpio));
/* enable gpio pins for output */
setbits8(&wkup_gpio->wkup_gpioe, reset);
setbits32(&simple_gpio->simple_gpioe, sync | out);
setbits8(&wkup_gpio->wkup_ddr, reset);
setbits32(&simple_gpio->simple_ddr, sync | out);
/* Assert cold reset */
clrbits32(&simple_gpio->simple_dvo, sync | out);
clrbits8(&wkup_gpio->wkup_dvo, reset);
/* wait for 1 us */
udelay(1);
/* Deassert reset */
setbits8(&wkup_gpio->wkup_dvo, reset);
/* wait at least 200ns */
/* 7 ~= (200ns * timebase) / ns2sec */
__delay(7);
/* Restore pin-muxing */
out_be32(&simple_gpio->port_config, mux);
spin_unlock_irqrestore(&gpio_lock, flags);
return 0;
}
EXPORT_SYMBOL(mpc5200_psc_ac97_gpio_reset);
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