kernel-ark/arch/arm/plat-s3c24xx/pm.c
Ben Dooks 62feee648c [ARM] 4784/1: S3C24XX: Fix GPIO restore glitches
The core resume code may have caused glitches in the GPIO when
restoring the GPIO state due to the order in which the GPIO registers
were being written.

Change the restore process take into account the state of the
GPIOs on resume and the state the system wants to restore them to.

See the code comments in the patch for more details of the process.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-01-28 13:20:51 +00:00

815 lines
19 KiB
C

/* linux/arch/arm/plat-s3c24xx/pm.c
*
* Copyright (c) 2004,2006 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C24XX Power Manager (Suspend-To-RAM) support
*
* See Documentation/arm/Samsung-S3C24XX/Suspend.txt for more information
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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
*
* Parts based on arch/arm/mach-pxa/pm.c
*
* Thanks to Dimitry Andric for debugging
*/
#include <linux/init.h>
#include <linux/suspend.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/crc32.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/serial_core.h>
#include <asm/cacheflush.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/plat-s3c/regs-serial.h>
#include <asm/arch/regs-clock.h>
#include <asm/arch/regs-gpio.h>
#include <asm/arch/regs-mem.h>
#include <asm/arch/regs-irq.h>
#include <asm/mach/time.h>
#include <asm/plat-s3c24xx/pm.h>
/* for external use */
unsigned long s3c_pm_flags;
#define PFX "s3c24xx-pm: "
static struct sleep_save core_save[] = {
SAVE_ITEM(S3C2410_LOCKTIME),
SAVE_ITEM(S3C2410_CLKCON),
/* we restore the timings here, with the proviso that the board
* brings the system up in an slower, or equal frequency setting
* to the original system.
*
* if we cannot guarantee this, then things are going to go very
* wrong here, as we modify the refresh and both pll settings.
*/
SAVE_ITEM(S3C2410_BWSCON),
SAVE_ITEM(S3C2410_BANKCON0),
SAVE_ITEM(S3C2410_BANKCON1),
SAVE_ITEM(S3C2410_BANKCON2),
SAVE_ITEM(S3C2410_BANKCON3),
SAVE_ITEM(S3C2410_BANKCON4),
SAVE_ITEM(S3C2410_BANKCON5),
SAVE_ITEM(S3C2410_CLKDIVN),
SAVE_ITEM(S3C2410_MPLLCON),
SAVE_ITEM(S3C2410_UPLLCON),
SAVE_ITEM(S3C2410_CLKSLOW),
SAVE_ITEM(S3C2410_REFRESH),
};
static struct gpio_sleep {
void __iomem *base;
unsigned int gpcon;
unsigned int gpdat;
unsigned int gpup;
} gpio_save[] = {
[0] = {
.base = S3C2410_GPACON,
},
[1] = {
.base = S3C2410_GPBCON,
},
[2] = {
.base = S3C2410_GPCCON,
},
[3] = {
.base = S3C2410_GPDCON,
},
[4] = {
.base = S3C2410_GPECON,
},
[5] = {
.base = S3C2410_GPFCON,
},
[6] = {
.base = S3C2410_GPGCON,
},
[7] = {
.base = S3C2410_GPHCON,
},
};
static struct sleep_save misc_save[] = {
SAVE_ITEM(S3C2410_DCLKCON),
};
#ifdef CONFIG_S3C2410_PM_DEBUG
#define SAVE_UART(va) \
SAVE_ITEM((va) + S3C2410_ULCON), \
SAVE_ITEM((va) + S3C2410_UCON), \
SAVE_ITEM((va) + S3C2410_UFCON), \
SAVE_ITEM((va) + S3C2410_UMCON), \
SAVE_ITEM((va) + S3C2410_UBRDIV)
static struct sleep_save uart_save[] = {
SAVE_UART(S3C24XX_VA_UART0),
SAVE_UART(S3C24XX_VA_UART1),
#ifndef CONFIG_CPU_S3C2400
SAVE_UART(S3C24XX_VA_UART2),
#endif
};
/* debug
*
* we send the debug to printascii() to allow it to be seen if the
* system never wakes up from the sleep
*/
extern void printascii(const char *);
void pm_dbg(const char *fmt, ...)
{
va_list va;
char buff[256];
va_start(va, fmt);
vsprintf(buff, fmt, va);
va_end(va);
printascii(buff);
}
static void s3c2410_pm_debug_init(void)
{
unsigned long tmp = __raw_readl(S3C2410_CLKCON);
/* re-start uart clocks */
tmp |= S3C2410_CLKCON_UART0;
tmp |= S3C2410_CLKCON_UART1;
tmp |= S3C2410_CLKCON_UART2;
__raw_writel(tmp, S3C2410_CLKCON);
udelay(10);
}
#define DBG(fmt...) pm_dbg(fmt)
#else
#define DBG(fmt...) printk(KERN_DEBUG fmt)
#define s3c2410_pm_debug_init() do { } while(0)
static struct sleep_save uart_save[] = {};
#endif
#if defined(CONFIG_S3C2410_PM_CHECK) && CONFIG_S3C2410_PM_CHECK_CHUNKSIZE != 0
/* suspend checking code...
*
* this next area does a set of crc checks over all the installed
* memory, so the system can verify if the resume was ok.
*
* CONFIG_S3C2410_PM_CHECK_CHUNKSIZE defines the block-size for the CRC,
* increasing it will mean that the area corrupted will be less easy to spot,
* and reducing the size will cause the CRC save area to grow
*/
#define CHECK_CHUNKSIZE (CONFIG_S3C2410_PM_CHECK_CHUNKSIZE * 1024)
static u32 crc_size; /* size needed for the crc block */
static u32 *crcs; /* allocated over suspend/resume */
typedef u32 *(run_fn_t)(struct resource *ptr, u32 *arg);
/* s3c2410_pm_run_res
*
* go thorugh the given resource list, and look for system ram
*/
static void s3c2410_pm_run_res(struct resource *ptr, run_fn_t fn, u32 *arg)
{
while (ptr != NULL) {
if (ptr->child != NULL)
s3c2410_pm_run_res(ptr->child, fn, arg);
if ((ptr->flags & IORESOURCE_MEM) &&
strcmp(ptr->name, "System RAM") == 0) {
DBG("Found system RAM at %08lx..%08lx\n",
ptr->start, ptr->end);
arg = (fn)(ptr, arg);
}
ptr = ptr->sibling;
}
}
static void s3c2410_pm_run_sysram(run_fn_t fn, u32 *arg)
{
s3c2410_pm_run_res(&iomem_resource, fn, arg);
}
static u32 *s3c2410_pm_countram(struct resource *res, u32 *val)
{
u32 size = (u32)(res->end - res->start)+1;
size += CHECK_CHUNKSIZE-1;
size /= CHECK_CHUNKSIZE;
DBG("Area %08lx..%08lx, %d blocks\n", res->start, res->end, size);
*val += size * sizeof(u32);
return val;
}
/* s3c2410_pm_prepare_check
*
* prepare the necessary information for creating the CRCs. This
* must be done before the final save, as it will require memory
* allocating, and thus touching bits of the kernel we do not
* know about.
*/
static void s3c2410_pm_check_prepare(void)
{
crc_size = 0;
s3c2410_pm_run_sysram(s3c2410_pm_countram, &crc_size);
DBG("s3c2410_pm_prepare_check: %u checks needed\n", crc_size);
crcs = kmalloc(crc_size+4, GFP_KERNEL);
if (crcs == NULL)
printk(KERN_ERR "Cannot allocated CRC save area\n");
}
static u32 *s3c2410_pm_makecheck(struct resource *res, u32 *val)
{
unsigned long addr, left;
for (addr = res->start; addr < res->end;
addr += CHECK_CHUNKSIZE) {
left = res->end - addr;
if (left > CHECK_CHUNKSIZE)
left = CHECK_CHUNKSIZE;
*val = crc32_le(~0, phys_to_virt(addr), left);
val++;
}
return val;
}
/* s3c2410_pm_check_store
*
* compute the CRC values for the memory blocks before the final
* sleep.
*/
static void s3c2410_pm_check_store(void)
{
if (crcs != NULL)
s3c2410_pm_run_sysram(s3c2410_pm_makecheck, crcs);
}
/* in_region
*
* return TRUE if the area defined by ptr..ptr+size contatins the
* what..what+whatsz
*/
static inline int in_region(void *ptr, int size, void *what, size_t whatsz)
{
if ((what+whatsz) < ptr)
return 0;
if (what > (ptr+size))
return 0;
return 1;
}
static u32 *s3c2410_pm_runcheck(struct resource *res, u32 *val)
{
void *save_at = phys_to_virt(s3c2410_sleep_save_phys);
unsigned long addr;
unsigned long left;
void *ptr;
u32 calc;
for (addr = res->start; addr < res->end;
addr += CHECK_CHUNKSIZE) {
left = res->end - addr;
if (left > CHECK_CHUNKSIZE)
left = CHECK_CHUNKSIZE;
ptr = phys_to_virt(addr);
if (in_region(ptr, left, crcs, crc_size)) {
DBG("skipping %08lx, has crc block in\n", addr);
goto skip_check;
}
if (in_region(ptr, left, save_at, 32*4 )) {
DBG("skipping %08lx, has save block in\n", addr);
goto skip_check;
}
/* calculate and check the checksum */
calc = crc32_le(~0, ptr, left);
if (calc != *val) {
printk(KERN_ERR PFX "Restore CRC error at "
"%08lx (%08x vs %08x)\n", addr, calc, *val);
DBG("Restore CRC error at %08lx (%08x vs %08x)\n",
addr, calc, *val);
}
skip_check:
val++;
}
return val;
}
/* s3c2410_pm_check_restore
*
* check the CRCs after the restore event and free the memory used
* to hold them
*/
static void s3c2410_pm_check_restore(void)
{
if (crcs != NULL) {
s3c2410_pm_run_sysram(s3c2410_pm_runcheck, crcs);
kfree(crcs);
crcs = NULL;
}
}
#else
#define s3c2410_pm_check_prepare() do { } while(0)
#define s3c2410_pm_check_restore() do { } while(0)
#define s3c2410_pm_check_store() do { } while(0)
#endif
/* helper functions to save and restore register state */
void s3c2410_pm_do_save(struct sleep_save *ptr, int count)
{
for (; count > 0; count--, ptr++) {
ptr->val = __raw_readl(ptr->reg);
DBG("saved %p value %08lx\n", ptr->reg, ptr->val);
}
}
/* s3c2410_pm_do_restore
*
* restore the system from the given list of saved registers
*
* Note, we do not use DBG() in here, as the system may not have
* restore the UARTs state yet
*/
void s3c2410_pm_do_restore(struct sleep_save *ptr, int count)
{
for (; count > 0; count--, ptr++) {
printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
ptr->reg, ptr->val, __raw_readl(ptr->reg));
__raw_writel(ptr->val, ptr->reg);
}
}
/* s3c2410_pm_do_restore_core
*
* similar to s3c2410_pm_do_restore_core
*
* WARNING: Do not put any debug in here that may effect memory or use
* peripherals, as things may be changing!
*/
static void s3c2410_pm_do_restore_core(struct sleep_save *ptr, int count)
{
for (; count > 0; count--, ptr++) {
__raw_writel(ptr->val, ptr->reg);
}
}
/* s3c2410_pm_show_resume_irqs
*
* print any IRQs asserted at resume time (ie, we woke from)
*/
static void s3c2410_pm_show_resume_irqs(int start, unsigned long which,
unsigned long mask)
{
int i;
which &= ~mask;
for (i = 0; i <= 31; i++) {
if ((which) & (1L<<i)) {
DBG("IRQ %d asserted at resume\n", start+i);
}
}
}
/* s3c2410_pm_check_resume_pin
*
* check to see if the pin is configured correctly for sleep mode, and
* make any necessary adjustments if it is not
*/
static void s3c2410_pm_check_resume_pin(unsigned int pin, unsigned int irqoffs)
{
unsigned long irqstate;
unsigned long pinstate;
int irq = s3c2410_gpio_getirq(pin);
if (irqoffs < 4)
irqstate = s3c_irqwake_intmask & (1L<<irqoffs);
else
irqstate = s3c_irqwake_eintmask & (1L<<irqoffs);
pinstate = s3c2410_gpio_getcfg(pin);
if (!irqstate) {
if (pinstate == S3C2410_GPIO_IRQ)
DBG("Leaving IRQ %d (pin %d) enabled\n", irq, pin);
} else {
if (pinstate == S3C2410_GPIO_IRQ) {
DBG("Disabling IRQ %d (pin %d)\n", irq, pin);
s3c2410_gpio_cfgpin(pin, S3C2410_GPIO_INPUT);
}
}
}
/* s3c2410_pm_configure_extint
*
* configure all external interrupt pins
*/
static void s3c2410_pm_configure_extint(void)
{
int pin;
/* for each of the external interrupts (EINT0..EINT15) we
* need to check wether it is an external interrupt source,
* and then configure it as an input if it is not
*/
for (pin = S3C2410_GPF0; pin <= S3C2410_GPF7; pin++) {
s3c2410_pm_check_resume_pin(pin, pin - S3C2410_GPF0);
}
for (pin = S3C2410_GPG0; pin <= S3C2410_GPG7; pin++) {
s3c2410_pm_check_resume_pin(pin, (pin - S3C2410_GPG0)+8);
}
}
/* offsets for CON/DAT/UP registers */
#define OFFS_CON (S3C2410_GPACON - S3C2410_GPACON)
#define OFFS_DAT (S3C2410_GPADAT - S3C2410_GPACON)
#define OFFS_UP (S3C2410_GPBUP - S3C2410_GPBCON)
/* s3c2410_pm_save_gpios()
*
* Save the state of the GPIOs
*/
static void s3c2410_pm_save_gpios(void)
{
struct gpio_sleep *gps = gpio_save;
unsigned int gpio;
for (gpio = 0; gpio < ARRAY_SIZE(gpio_save); gpio++, gps++) {
void __iomem *base = gps->base;
gps->gpcon = __raw_readl(base + OFFS_CON);
gps->gpdat = __raw_readl(base + OFFS_DAT);
if (gpio > 0)
gps->gpup = __raw_readl(base + OFFS_UP);
}
}
/* Test whether the given masked+shifted bits of an GPIO configuration
* are one of the SFN (special function) modes. */
static inline int is_sfn(unsigned long con)
{
return (con == 2 || con == 3);
}
/* Test if the given masked+shifted GPIO configuration is an input */
static inline int is_in(unsigned long con)
{
return con == 0;
}
/* Test if the given masked+shifted GPIO configuration is an output */
static inline int is_out(unsigned long con)
{
return con == 1;
}
/* s3c2410_pm_restore_gpio()
*
* Restore one of the GPIO banks that was saved during suspend. This is
* not as simple as once thought, due to the possibility of glitches
* from the order that the CON and DAT registers are set in.
*
* The three states the pin can be are {IN,OUT,SFN} which gives us 9
* combinations of changes to check. Three of these, if the pin stays
* in the same configuration can be discounted. This leaves us with
* the following:
*
* { IN => OUT } Change DAT first
* { IN => SFN } Change CON first
* { OUT => SFN } Change CON first, so new data will not glitch
* { OUT => IN } Change CON first, so new data will not glitch
* { SFN => IN } Change CON first
* { SFN => OUT } Change DAT first, so new data will not glitch [1]
*
* We do not currently deal with the UP registers as these control
* weak resistors, so a small delay in change should not need to bring
* these into the calculations.
*
* [1] this assumes that writing to a pin DAT whilst in SFN will set the
* state for when it is next output.
*/
static void s3c2410_pm_restore_gpio(int index, struct gpio_sleep *gps)
{
void __iomem *base = gps->base;
unsigned long gps_gpcon = gps->gpcon;
unsigned long gps_gpdat = gps->gpdat;
unsigned long old_gpcon;
unsigned long old_gpdat;
unsigned long old_gpup = 0x0;
unsigned long gpcon;
int nr;
old_gpcon = __raw_readl(base + OFFS_CON);
old_gpdat = __raw_readl(base + OFFS_DAT);
if (base == S3C2410_GPACON) {
/* GPACON only has one bit per control / data and no PULLUPs.
* GPACON[x] = 0 => Output, 1 => SFN */
/* first set all SFN bits to SFN */
gpcon = old_gpcon | gps->gpcon;
__raw_writel(gpcon, base + OFFS_CON);
/* now set all the other bits */
__raw_writel(gps_gpdat, base + OFFS_DAT);
__raw_writel(gps_gpcon, base + OFFS_CON);
} else {
unsigned long old, new, mask;
unsigned long change_mask = 0x0;
old_gpup = __raw_readl(base + OFFS_UP);
/* Create a change_mask of all the items that need to have
* their CON value changed before their DAT value, so that
* we minimise the work between the two settings.
*/
for (nr = 0, mask = 0x03; nr < 32; nr += 2, mask <<= 2) {
old = (old_gpcon & mask) >> nr;
new = (gps_gpcon & mask) >> nr;
/* If there is no change, then skip */
if (old == new)
continue;
/* If both are special function, then skip */
if (is_sfn(old) && is_sfn(new))
continue;
/* Change is IN => OUT, do not change now */
if (is_in(old) && is_out(new))
continue;
/* Change is SFN => OUT, do not change now */
if (is_sfn(old) && is_out(new))
continue;
/* We should now be at the case of IN=>SFN,
* OUT=>SFN, OUT=>IN, SFN=>IN. */
change_mask |= mask;
}
/* Write the new CON settings */
gpcon = old_gpcon & ~change_mask;
gpcon |= gps_gpcon & change_mask;
__raw_writel(gpcon, base + OFFS_CON);
/* Now change any items that require DAT,CON */
__raw_writel(gps_gpdat, base + OFFS_DAT);
__raw_writel(gps_gpcon, base + OFFS_CON);
__raw_writel(gps->gpup, base + OFFS_UP);
}
DBG("GPIO[%d] CON %08lx => %08lx, DAT %08lx => %08lx\n",
index, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat);
}
/** s3c2410_pm_restore_gpios()
*
* Restore the state of the GPIOs
*/
static void s3c2410_pm_restore_gpios(void)
{
struct gpio_sleep *gps = gpio_save;
int gpio;
for (gpio = 0; gpio < ARRAY_SIZE(gpio_save); gpio++, gps++) {
s3c2410_pm_restore_gpio(gpio, gps);
}
}
void (*pm_cpu_prep)(void);
void (*pm_cpu_sleep)(void);
#define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
/* s3c2410_pm_enter
*
* central control for sleep/resume process
*/
static int s3c2410_pm_enter(suspend_state_t state)
{
unsigned long regs_save[16];
/* ensure the debug is initialised (if enabled) */
s3c2410_pm_debug_init();
DBG("s3c2410_pm_enter(%d)\n", state);
if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
printk(KERN_ERR PFX "error: no cpu sleep functions set\n");
return -EINVAL;
}
/* check if we have anything to wake-up with... bad things seem
* to happen if you suspend with no wakeup (system will often
* require a full power-cycle)
*/
if (!any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
!any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
printk(KERN_ERR PFX "No sources enabled for wake-up!\n");
printk(KERN_ERR PFX "Aborting sleep\n");
return -EINVAL;
}
/* prepare check area if configured */
s3c2410_pm_check_prepare();
/* store the physical address of the register recovery block */
s3c2410_sleep_save_phys = virt_to_phys(regs_save);
DBG("s3c2410_sleep_save_phys=0x%08lx\n", s3c2410_sleep_save_phys);
/* save all necessary core registers not covered by the drivers */
s3c2410_pm_save_gpios();
s3c2410_pm_do_save(misc_save, ARRAY_SIZE(misc_save));
s3c2410_pm_do_save(core_save, ARRAY_SIZE(core_save));
s3c2410_pm_do_save(uart_save, ARRAY_SIZE(uart_save));
/* set the irq configuration for wake */
s3c2410_pm_configure_extint();
DBG("sleep: irq wakeup masks: %08lx,%08lx\n",
s3c_irqwake_intmask, s3c_irqwake_eintmask);
__raw_writel(s3c_irqwake_intmask, S3C2410_INTMSK);
__raw_writel(s3c_irqwake_eintmask, S3C2410_EINTMASK);
/* ack any outstanding external interrupts before we go to sleep */
__raw_writel(__raw_readl(S3C2410_EINTPEND), S3C2410_EINTPEND);
__raw_writel(__raw_readl(S3C2410_INTPND), S3C2410_INTPND);
__raw_writel(__raw_readl(S3C2410_SRCPND), S3C2410_SRCPND);
/* call cpu specific preparation */
pm_cpu_prep();
/* flush cache back to ram */
flush_cache_all();
s3c2410_pm_check_store();
/* send the cpu to sleep... */
__raw_writel(0x00, S3C2410_CLKCON); /* turn off clocks over sleep */
/* s3c2410_cpu_save will also act as our return point from when
* we resume as it saves its own register state, so use the return
* code to differentiate return from save and return from sleep */
if (s3c2410_cpu_save(regs_save) == 0) {
flush_cache_all();
pm_cpu_sleep();
}
/* restore the cpu state */
cpu_init();
/* restore the system state */
s3c2410_pm_do_restore_core(core_save, ARRAY_SIZE(core_save));
s3c2410_pm_do_restore(misc_save, ARRAY_SIZE(misc_save));
s3c2410_pm_do_restore(uart_save, ARRAY_SIZE(uart_save));
s3c2410_pm_restore_gpios();
s3c2410_pm_debug_init();
/* check what irq (if any) restored the system */
DBG("post sleep: IRQs 0x%08x, 0x%08x\n",
__raw_readl(S3C2410_SRCPND),
__raw_readl(S3C2410_EINTPEND));
s3c2410_pm_show_resume_irqs(IRQ_EINT0, __raw_readl(S3C2410_SRCPND),
s3c_irqwake_intmask);
s3c2410_pm_show_resume_irqs(IRQ_EINT4-4, __raw_readl(S3C2410_EINTPEND),
s3c_irqwake_eintmask);
DBG("post sleep, preparing to return\n");
s3c2410_pm_check_restore();
/* ok, let's return from sleep */
DBG("S3C2410 PM Resume (post-restore)\n");
return 0;
}
static struct platform_suspend_ops s3c2410_pm_ops = {
.enter = s3c2410_pm_enter,
.valid = suspend_valid_only_mem,
};
/* s3c2410_pm_init
*
* Attach the power management functions. This should be called
* from the board specific initialisation if the board supports
* it.
*/
int __init s3c2410_pm_init(void)
{
printk("S3C2410 Power Management, (c) 2004 Simtec Electronics\n");
suspend_set_ops(&s3c2410_pm_ops);
return 0;
}