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acrn-kernel/arch/arm/plat-s3c24xx/pm.c

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/* 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/serial_core.h>
#include <linux/io.h>
#include <plat/regs-serial.h>
#include <mach/regs-clock.h>
#include <mach/regs-gpio.h>
#include <mach/regs-mem.h>
#include <mach/regs-irq.h>
#include <asm/mach/time.h>
#include <plat/pm.h>
#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),
#ifndef CONFIG_CPU_FREQ
SAVE_ITEM(S3C2410_CLKDIVN),
SAVE_ITEM(S3C2410_MPLLCON),
SAVE_ITEM(S3C2410_REFRESH),
#endif
SAVE_ITEM(S3C2410_UPLLCON),
SAVE_ITEM(S3C2410_CLKSLOW),
};
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),
};
/* s3c_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 s3c_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)
S3C_PMDBG("Leaving IRQ %d (pin %d) enabled\n", irq, pin);
} else {
if (pinstate == S3C2410_GPIO_IRQ) {
S3C_PMDBG("Disabling IRQ %d (pin %d)\n", irq, pin);
s3c2410_gpio_cfgpin(pin, S3C2410_GPIO_INPUT);
}
}
}
/* s3c_pm_configure_extint
*
* configure all external interrupt pins
*/
void s3c_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++) {
s3c_pm_check_resume_pin(pin, pin - S3C2410_GPF0);
}
for (pin = S3C2410_GPG0; pin <= S3C2410_GPG7; pin++) {
s3c_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)
/* s3c_pm_save_gpios()
*
* Save the state of the GPIOs
*/
void s3c_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 the given GPIO bank
* @index: The number of the GPIO bank being resumed.
* @gps: The sleep confgiuration for the bank.
*
* 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);
}
S3C_PMDBG("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
*/
void s3c_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 s3c_pm_restore_core(void)
{
s3c_pm_do_restore_core(core_save, ARRAY_SIZE(core_save));
s3c_pm_do_restore(misc_save, ARRAY_SIZE(misc_save));
}
void s3c_pm_save_core(void)
{
s3c_pm_do_save(misc_save, ARRAY_SIZE(misc_save));
s3c_pm_do_save(core_save, ARRAY_SIZE(core_save));
}
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