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/*
* arch/arm/mach-at91/pm.c
* AT91 Power Management
*
* Copyright (C) 2005 David Brownell
*
* 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.
*/
#include <linux/gpio.h>
#include <linux/suspend.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/genalloc.h>
#include <linux/interrupt.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/clk/at91_pmc.h>
#include <asm/irq.h>
#include <linux/atomic.h>
#include <asm/mach/time.h>
#include <asm/mach/irq.h>
#include <mach/cpu.h>
#include <mach/hardware.h>
#include "generic.h"
#include "pm.h"
static struct {
unsigned long uhp_udp_mask;
int memctrl;
} at91_pm_data;
static void (*at91_pm_standby)(void);
void __iomem *at91_ramc_base[2];
static int at91_pm_valid_state(suspend_state_t state)
{
switch (state) {
case PM_SUSPEND_ON:
case PM_SUSPEND_STANDBY:
case PM_SUSPEND_MEM:
return 1;
default:
return 0;
}
}
static suspend_state_t target_state;
/*
* Called after processes are frozen, but before we shutdown devices.
*/
static int at91_pm_begin(suspend_state_t state)
{
target_state = state;
return 0;
}
/*
* Verify that all the clocks are correct before entering
* slow-clock mode.
*/
static int at91_pm_verify_clocks(void)
{
unsigned long scsr;
int i;
scsr = at91_pmc_read(AT91_PMC_SCSR);
/* USB must not be using PLLB */
if ((scsr & at91_pm_data.uhp_udp_mask) != 0) {
pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
return 0;
}
/* PCK0..PCK3 must be disabled, or configured to use clk32k */
for (i = 0; i < 4; i++) {
u32 css;
if ((scsr & (AT91_PMC_PCK0 << i)) == 0)
continue;
css = at91_pmc_read(AT91_PMC_PCKR(i)) & AT91_PMC_CSS;
if (css != AT91_PMC_CSS_SLOW) {
pr_err("AT91: PM - Suspend-to-RAM with PCK%d src %d\n", i, css);
return 0;
}
}
return 1;
}
/*
* Call this from platform driver suspend() to see how deeply to suspend.
* For example, some controllers (like OHCI) need one of the PLL clocks
* in order to act as a wakeup source, and those are not available when
* going into slow clock mode.
*
* REVISIT: generalize as clk_will_be_available(clk)? Other platforms have
* the very same problem (but not using at91 main_clk), and it'd be better
* to add one generic API rather than lots of platform-specific ones.
*/
int at91_suspend_entering_slow_clock(void)
{
return (target_state == PM_SUSPEND_MEM);
}
EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
static void (*slow_clock)(void __iomem *pmc, void __iomem *ramc0,
void __iomem *ramc1, int memctrl);
#ifdef CONFIG_AT91_SLOW_CLOCK
extern void at91_slow_clock(void __iomem *pmc, void __iomem *ramc0,
void __iomem *ramc1, int memctrl);
extern u32 at91_slow_clock_sz;
#endif
static int at91_pm_enter(suspend_state_t state)
{
at91_pinctrl_gpio_suspend();
switch (state) {
/*
* Suspend-to-RAM is like STANDBY plus slow clock mode, so
* drivers must suspend more deeply: only the master clock
* controller may be using the main oscillator.
*/
case PM_SUSPEND_MEM:
/*
* Ensure that clocks are in a valid state.
*/
if (!at91_pm_verify_clocks())
goto error;
/*
* Enter slow clock mode by switching over to clk32k and
* turning off the main oscillator; reverse on wakeup.
*/
if (slow_clock) {
#ifdef CONFIG_AT91_SLOW_CLOCK
/* copy slow_clock handler to SRAM, and call it */
memcpy(slow_clock, at91_slow_clock, at91_slow_clock_sz);
#endif
slow_clock(at91_pmc_base, at91_ramc_base[0],
at91_ramc_base[1],
at91_pm_data.memctrl);
break;
} else {
pr_info("AT91: PM - no slow clock mode enabled ...\n");
/* FALLTHROUGH leaving master clock alone */
}
/*
* STANDBY mode has *all* drivers suspended; ignores irqs not
* marked as 'wakeup' event sources; and reduces DRAM power.
* But otherwise it's identical to PM_SUSPEND_ON: cpu idle, and
* nothing fancy done with main or cpu clocks.
*/
case PM_SUSPEND_STANDBY:
/*
* NOTE: the Wait-for-Interrupt instruction needs to be
* in icache so no SDRAM accesses are needed until the
* wakeup IRQ occurs and self-refresh is terminated.
* For ARM 926 based chips, this requirement is weaker
* as at91sam9 can access a RAM in self-refresh mode.
*/
if (at91_pm_standby)
at91_pm_standby();
break;
case PM_SUSPEND_ON:
cpu_do_idle();
break;
default:
pr_debug("AT91: PM - bogus suspend state %d\n", state);
goto error;
}
error:
target_state = PM_SUSPEND_ON;
at91_pinctrl_gpio_resume();
return 0;
}
/*
* Called right prior to thawing processes.
*/
static void at91_pm_end(void)
{
target_state = PM_SUSPEND_ON;
}
static const struct platform_suspend_ops at91_pm_ops = {
.valid = at91_pm_valid_state,
.begin = at91_pm_begin,
.enter = at91_pm_enter,
.end = at91_pm_end,
};
static struct platform_device at91_cpuidle_device = {
.name = "cpuidle-at91",
};
void at91_pm_set_standby(void (*at91_standby)(void))
{
if (at91_standby) {
at91_cpuidle_device.dev.platform_data = at91_standby;
at91_pm_standby = at91_standby;
}
}
static const struct of_device_id ramc_ids[] __initconst = {
{ .compatible = "atmel,at91rm9200-sdramc", .data = at91rm9200_standby },
{ .compatible = "atmel,at91sam9260-sdramc", .data = at91sam9_sdram_standby },
{ .compatible = "atmel,at91sam9g45-ddramc", .data = at91_ddr_standby },
{ .compatible = "atmel,sama5d3-ddramc", .data = at91_ddr_standby },
{ /*sentinel*/ }
};
static __init void at91_dt_ramc(void)
{
struct device_node *np;
const struct of_device_id *of_id;
int idx = 0;
const void *standby = NULL;
for_each_matching_node_and_match(np, ramc_ids, &of_id) {
at91_ramc_base[idx] = of_iomap(np, 0);
if (!at91_ramc_base[idx])
panic(pr_fmt("unable to map ramc[%d] cpu registers\n"), idx);
if (!standby)
standby = of_id->data;
idx++;
}
if (!idx)
panic(pr_fmt("unable to find compatible ram controller node in dtb\n"));
if (!standby) {
pr_warn("ramc no standby function available\n");
return;
}
at91_pm_set_standby(standby);
}
#ifdef CONFIG_AT91_SLOW_CLOCK
static void __init at91_pm_sram_init(void)
{
struct gen_pool *sram_pool;
phys_addr_t sram_pbase;
unsigned long sram_base;
struct device_node *node;
struct platform_device *pdev;
node = of_find_compatible_node(NULL, NULL, "mmio-sram");
if (!node) {
pr_warn("%s: failed to find sram node!\n", __func__);
return;
}
pdev = of_find_device_by_node(node);
if (!pdev) {
pr_warn("%s: failed to find sram device!\n", __func__);
goto put_node;
}
sram_pool = dev_get_gen_pool(&pdev->dev);
if (!sram_pool) {
pr_warn("%s: sram pool unavailable!\n", __func__);
goto put_node;
}
sram_base = gen_pool_alloc(sram_pool, at91_slow_clock_sz);
if (!sram_base) {
pr_warn("%s: unable to alloc ocram!\n", __func__);
goto put_node;
}
sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
slow_clock = __arm_ioremap_exec(sram_pbase, at91_slow_clock_sz, false);
put_node:
of_node_put(node);
}
#endif
static void __init at91_pm_init(void)
{
#ifdef CONFIG_AT91_SLOW_CLOCK
at91_pm_sram_init();
#endif
pr_info("AT91: Power Management%s\n", (slow_clock ? " (with slow clock mode)" : ""));
if (at91_cpuidle_device.dev.platform_data)
platform_device_register(&at91_cpuidle_device);
suspend_set_ops(&at91_pm_ops);
}
void __init at91rm9200_pm_init(void)
{
at91_dt_ramc();
/*
* AT91RM9200 SDRAM low-power mode cannot be used with self-refresh.
*/
at91_ramc_write(0, AT91RM9200_SDRAMC_LPR, 0);
at91_pm_data.uhp_udp_mask = AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP;
at91_pm_data.memctrl = AT91_MEMCTRL_MC;
at91_pm_init();
}
void __init at91sam9260_pm_init(void)
{
at91_dt_ramc();
at91_pm_data.memctrl = AT91_MEMCTRL_SDRAMC;
at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP;
return at91_pm_init();
}
void __init at91sam9g45_pm_init(void)
{
at91_dt_ramc();
at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP;
at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
return at91_pm_init();
}
void __init at91sam9x5_pm_init(void)
{
at91_dt_ramc();
at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP;
at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
return at91_pm_init();
}