https://github.com/torvalds/linux
Tip revision: bc33b0ca11e3df467777a4fa7639ba488c9d4911 authored by Linus Torvalds on 05 November 2016, 23:23:36 UTC
Linux 4.9-rc4
Linux 4.9-rc4
Tip revision: bc33b0c
pm.c
/*
* 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/platform_data/atmel.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 <asm/fncpy.h>
#include <asm/cacheflush.h>
#include <asm/system_misc.h>
#include "generic.h"
#include "pm.h"
static void __iomem *pmc;
/*
* FIXME: this is needed to communicate between the pinctrl driver and
* the PM implementation in the machine. Possibly part of the PM
* implementation should be moved down into the pinctrl driver and get
* called as part of the generic suspend/resume path.
*/
#ifdef CONFIG_PINCTRL_AT91
extern void at91_pinctrl_gpio_suspend(void);
extern void at91_pinctrl_gpio_resume(void);
#endif
static struct {
unsigned long uhp_udp_mask;
int memctrl;
} at91_pm_data;
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 = readl(pmc + 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 = readl(pmc + 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 (*at91_suspend_sram_fn)(void __iomem *pmc, void __iomem *ramc0,
void __iomem *ramc1, int memctrl);
extern void at91_pm_suspend_in_sram(void __iomem *pmc, void __iomem *ramc0,
void __iomem *ramc1, int memctrl);
extern u32 at91_pm_suspend_in_sram_sz;
static void at91_pm_suspend(suspend_state_t state)
{
unsigned int pm_data = at91_pm_data.memctrl;
pm_data |= (state == PM_SUSPEND_MEM) ?
AT91_PM_MODE(AT91_PM_SLOW_CLOCK) : 0;
flush_cache_all();
outer_disable();
at91_suspend_sram_fn(pmc, at91_ramc_base[0],
at91_ramc_base[1], pm_data);
outer_resume();
}
static int at91_pm_enter(suspend_state_t state)
{
#ifdef CONFIG_PINCTRL_AT91
at91_pinctrl_gpio_suspend();
#endif
switch (state) {
/*
* Suspend-to-RAM is like STANDBY plus slow clock mode, so
* drivers must suspend more deeply, the master clock switches
* to the clk32k and turns off the main oscillator
*/
case PM_SUSPEND_MEM:
/*
* Ensure that clocks are in a valid state.
*/
if (!at91_pm_verify_clocks())
goto error;
at91_pm_suspend(state);
break;
/*
* 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:
at91_pm_suspend(state);
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;
#ifdef CONFIG_PINCTRL_AT91
at91_pinctrl_gpio_resume();
#endif
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",
};
static void at91_pm_set_standby(void (*at91_standby)(void))
{
if (at91_standby)
at91_cpuidle_device.dev.platform_data = at91_standby;
}
/*
* The AT91RM9200 goes into self-refresh mode with this command, and will
* terminate self-refresh automatically on the next SDRAM access.
*
* Self-refresh mode is exited as soon as a memory access is made, but we don't
* know for sure when that happens. However, we need to restore the low-power
* mode if it was enabled before going idle. Restoring low-power mode while
* still in self-refresh is "not recommended", but seems to work.
*/
static void at91rm9200_standby(void)
{
u32 lpr = at91_ramc_read(0, AT91_MC_SDRAMC_LPR);
asm volatile(
"b 1f\n\t"
".align 5\n\t"
"1: mcr p15, 0, %0, c7, c10, 4\n\t"
" str %0, [%1, %2]\n\t"
" str %3, [%1, %4]\n\t"
" mcr p15, 0, %0, c7, c0, 4\n\t"
" str %5, [%1, %2]"
:
: "r" (0), "r" (at91_ramc_base[0]), "r" (AT91_MC_SDRAMC_LPR),
"r" (1), "r" (AT91_MC_SDRAMC_SRR),
"r" (lpr));
}
/* We manage both DDRAM/SDRAM controllers, we need more than one value to
* remember.
*/
static void at91_ddr_standby(void)
{
/* Those two values allow us to delay self-refresh activation
* to the maximum. */
u32 lpr0, lpr1 = 0;
u32 saved_lpr0, saved_lpr1 = 0;
if (at91_ramc_base[1]) {
saved_lpr1 = at91_ramc_read(1, AT91_DDRSDRC_LPR);
lpr1 = saved_lpr1 & ~AT91_DDRSDRC_LPCB;
lpr1 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
}
saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR);
lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB;
lpr0 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
/* self-refresh mode now */
at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0);
if (at91_ramc_base[1])
at91_ramc_write(1, AT91_DDRSDRC_LPR, lpr1);
cpu_do_idle();
at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
if (at91_ramc_base[1])
at91_ramc_write(1, AT91_DDRSDRC_LPR, saved_lpr1);
}
/* We manage both DDRAM/SDRAM controllers, we need more than one value to
* remember.
*/
static void at91sam9_sdram_standby(void)
{
u32 lpr0, lpr1 = 0;
u32 saved_lpr0, saved_lpr1 = 0;
if (at91_ramc_base[1]) {
saved_lpr1 = at91_ramc_read(1, AT91_SDRAMC_LPR);
lpr1 = saved_lpr1 & ~AT91_SDRAMC_LPCB;
lpr1 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
}
saved_lpr0 = at91_ramc_read(0, AT91_SDRAMC_LPR);
lpr0 = saved_lpr0 & ~AT91_SDRAMC_LPCB;
lpr0 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
/* self-refresh mode now */
at91_ramc_write(0, AT91_SDRAMC_LPR, lpr0);
if (at91_ramc_base[1])
at91_ramc_write(1, AT91_SDRAMC_LPR, lpr1);
cpu_do_idle();
at91_ramc_write(0, AT91_SDRAMC_LPR, saved_lpr0);
if (at91_ramc_base[1])
at91_ramc_write(1, AT91_SDRAMC_LPR, saved_lpr1);
}
static const struct of_device_id const 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);
}
static void at91rm9200_idle(void)
{
/*
* Disable the processor clock. The processor will be automatically
* re-enabled by an interrupt or by a reset.
*/
writel(AT91_PMC_PCK, pmc + AT91_PMC_SCDR);
}
static void at91sam9_idle(void)
{
writel(AT91_PMC_PCK, pmc + AT91_PMC_SCDR);
cpu_do_idle();
}
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 = NULL;
for_each_compatible_node(node, NULL, "mmio-sram") {
pdev = of_find_device_by_node(node);
if (pdev) {
of_node_put(node);
break;
}
}
if (!pdev) {
pr_warn("%s: failed to find sram device!\n", __func__);
return;
}
sram_pool = gen_pool_get(&pdev->dev, NULL);
if (!sram_pool) {
pr_warn("%s: sram pool unavailable!\n", __func__);
return;
}
sram_base = gen_pool_alloc(sram_pool, at91_pm_suspend_in_sram_sz);
if (!sram_base) {
pr_warn("%s: unable to alloc sram!\n", __func__);
return;
}
sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
at91_suspend_sram_fn = __arm_ioremap_exec(sram_pbase,
at91_pm_suspend_in_sram_sz, false);
if (!at91_suspend_sram_fn) {
pr_warn("SRAM: Could not map\n");
return;
}
/* Copy the pm suspend handler to SRAM */
at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
&at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
}
static const struct of_device_id atmel_pmc_ids[] __initconst = {
{ .compatible = "atmel,at91rm9200-pmc" },
{ .compatible = "atmel,at91sam9260-pmc" },
{ .compatible = "atmel,at91sam9g45-pmc" },
{ .compatible = "atmel,at91sam9n12-pmc" },
{ .compatible = "atmel,at91sam9x5-pmc" },
{ .compatible = "atmel,sama5d3-pmc" },
{ .compatible = "atmel,sama5d2-pmc" },
{ /* sentinel */ },
};
static void __init at91_pm_init(void (*pm_idle)(void))
{
struct device_node *pmc_np;
if (at91_cpuidle_device.dev.platform_data)
platform_device_register(&at91_cpuidle_device);
pmc_np = of_find_matching_node(NULL, atmel_pmc_ids);
pmc = of_iomap(pmc_np, 0);
if (!pmc) {
pr_err("AT91: PM not supported, PMC not found\n");
return;
}
if (pm_idle)
arm_pm_idle = pm_idle;
at91_pm_sram_init();
if (at91_suspend_sram_fn)
suspend_set_ops(&at91_pm_ops);
else
pr_info("AT91: PM not supported, due to no SRAM allocated\n");
}
void __init at91rm9200_pm_init(void)
{
at91_dt_ramc();
/*
* AT91RM9200 SDRAM low-power mode cannot be used with self-refresh.
*/
at91_ramc_write(0, AT91_MC_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(at91rm9200_idle);
}
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;
at91_pm_init(at91sam9_idle);
}
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;
at91_pm_init(at91sam9_idle);
}
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;
at91_pm_init(at91sam9_idle);
}
void __init sama5_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;
at91_pm_init(NULL);
}