https://github.com/torvalds/linux
Tip revision: b2cd1df66037e7c4697c7e40496bf7e4a5e16a2d authored by Linus Torvalds on 07 January 2018, 22:22:41 UTC
Linux 4.15-rc7
Linux 4.15-rc7
Tip revision: b2cd1df
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/genalloc.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/parser.h>
#include <linux/suspend.h>
#include <linux/clk/at91_pmc.h>
#include <asm/cacheflush.h>
#include <asm/fncpy.h>
#include <asm/system_misc.h>
#include <asm/suspend.h>
#include "generic.h"
#include "pm.h"
/*
* 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 const match_table_t pm_modes __initconst = {
{ 0, "standby" },
{ AT91_PM_SLOW_CLOCK, "ulp0" },
{ AT91_PM_BACKUP, "backup" },
{ -1, NULL },
};
static struct at91_pm_data pm_data = {
.standby_mode = 0,
.suspend_mode = AT91_PM_SLOW_CLOCK,
};
#define at91_ramc_read(id, field) \
__raw_readl(pm_data.ramc[id] + field)
#define at91_ramc_write(id, field, value) \
__raw_writel(value, pm_data.ramc[id] + field)
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 int canary = 0xA5A5A5A5;
static struct at91_pm_bu {
int suspended;
unsigned long reserved;
phys_addr_t canary;
phys_addr_t resume;
} *pm_bu;
/*
* Called after processes are frozen, but before we shutdown devices.
*/
static int at91_pm_begin(suspend_state_t state)
{
switch (state) {
case PM_SUSPEND_MEM:
pm_data.mode = pm_data.suspend_mode;
break;
case PM_SUSPEND_STANDBY:
pm_data.mode = pm_data.standby_mode;
break;
default:
pm_data.mode = -1;
}
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(pm_data.pmc + AT91_PMC_SCSR);
/* USB must not be using PLLB */
if ((scsr & 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(pm_data.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 (pm_data.mode >= AT91_PM_SLOW_CLOCK);
}
EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
static void (*at91_suspend_sram_fn)(struct at91_pm_data *);
extern void at91_pm_suspend_in_sram(struct at91_pm_data *pm_data);
extern u32 at91_pm_suspend_in_sram_sz;
static int at91_suspend_finish(unsigned long val)
{
flush_cache_all();
outer_disable();
at91_suspend_sram_fn(&pm_data);
return 0;
}
static void at91_pm_suspend(suspend_state_t state)
{
if (pm_data.mode == AT91_PM_BACKUP) {
pm_bu->suspended = 1;
cpu_suspend(0, at91_suspend_finish);
/* The SRAM is lost between suspend cycles */
at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
&at91_pm_suspend_in_sram,
at91_pm_suspend_in_sram_sz);
} else {
at91_suspend_finish(0);
}
outer_resume();
}
/*
* 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.
*
* AT91_PM_SLOW_CLOCK 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
*
* AT91_PM_BACKUP turns off the whole SoC after placing the DDR in self refresh
*/
static int at91_pm_enter(suspend_state_t state)
{
#ifdef CONFIG_PINCTRL_AT91
at91_pinctrl_gpio_suspend();
#endif
switch (state) {
case PM_SUSPEND_MEM:
case PM_SUSPEND_STANDBY:
/*
* Ensure that clocks are in a valid state.
*/
if ((pm_data.mode >= AT91_PM_SLOW_CLOCK) &&
!at91_pm_verify_clocks())
goto error;
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:
#ifdef CONFIG_PINCTRL_AT91
at91_pinctrl_gpio_resume();
#endif
return 0;
}
/*
* Called right prior to thawing processes.
*/
static void at91_pm_end(void)
{
}
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",
};
/*
* 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)
{
asm volatile(
"b 1f\n\t"
".align 5\n\t"
"1: mcr p15, 0, %0, c7, c10, 4\n\t"
" str %2, [%1, %3]\n\t"
" mcr p15, 0, %0, c7, c0, 4\n\t"
:
: "r" (0), "r" (pm_data.ramc[0]),
"r" (1), "r" (AT91_MC_SDRAMC_SRR));
}
/* 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 mdr, saved_mdr0, saved_mdr1 = 0;
u32 saved_lpr0, saved_lpr1 = 0;
/* LPDDR1 --> force DDR2 mode during self-refresh */
saved_mdr0 = at91_ramc_read(0, AT91_DDRSDRC_MDR);
if ((saved_mdr0 & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR) {
mdr = saved_mdr0 & ~AT91_DDRSDRC_MD;
mdr |= AT91_DDRSDRC_MD_DDR2;
at91_ramc_write(0, AT91_DDRSDRC_MDR, mdr);
}
if (pm_data.ramc[1]) {
saved_lpr1 = at91_ramc_read(1, AT91_DDRSDRC_LPR);
lpr1 = saved_lpr1 & ~AT91_DDRSDRC_LPCB;
lpr1 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
saved_mdr1 = at91_ramc_read(1, AT91_DDRSDRC_MDR);
if ((saved_mdr1 & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR) {
mdr = saved_mdr1 & ~AT91_DDRSDRC_MD;
mdr |= AT91_DDRSDRC_MD_DDR2;
at91_ramc_write(1, AT91_DDRSDRC_MDR, mdr);
}
}
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 (pm_data.ramc[1])
at91_ramc_write(1, AT91_DDRSDRC_LPR, lpr1);
cpu_do_idle();
at91_ramc_write(0, AT91_DDRSDRC_MDR, saved_mdr0);
at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
if (pm_data.ramc[1]) {
at91_ramc_write(0, AT91_DDRSDRC_MDR, saved_mdr1);
at91_ramc_write(1, AT91_DDRSDRC_LPR, saved_lpr1);
}
}
static void sama5d3_ddr_standby(void)
{
u32 lpr0;
u32 saved_lpr0;
saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR);
lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB;
lpr0 |= AT91_DDRSDRC_LPCB_POWER_DOWN;
at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0);
cpu_do_idle();
at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
}
/* 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 (pm_data.ramc[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 (pm_data.ramc[1])
at91_ramc_write(1, AT91_SDRAMC_LPR, lpr1);
cpu_do_idle();
at91_ramc_write(0, AT91_SDRAMC_LPR, saved_lpr0);
if (pm_data.ramc[1])
at91_ramc_write(1, AT91_SDRAMC_LPR, saved_lpr1);
}
struct ramc_info {
void (*idle)(void);
unsigned int memctrl;
};
static const struct ramc_info ramc_infos[] __initconst = {
{ .idle = at91rm9200_standby, .memctrl = AT91_MEMCTRL_MC},
{ .idle = at91sam9_sdram_standby, .memctrl = AT91_MEMCTRL_SDRAMC},
{ .idle = at91_ddr_standby, .memctrl = AT91_MEMCTRL_DDRSDR},
{ .idle = sama5d3_ddr_standby, .memctrl = AT91_MEMCTRL_DDRSDR},
};
static const struct of_device_id ramc_ids[] __initconst = {
{ .compatible = "atmel,at91rm9200-sdramc", .data = &ramc_infos[0] },
{ .compatible = "atmel,at91sam9260-sdramc", .data = &ramc_infos[1] },
{ .compatible = "atmel,at91sam9g45-ddramc", .data = &ramc_infos[2] },
{ .compatible = "atmel,sama5d3-ddramc", .data = &ramc_infos[3] },
{ /*sentinel*/ }
};
static __init void at91_dt_ramc(void)
{
struct device_node *np;
const struct of_device_id *of_id;
int idx = 0;
void *standby = NULL;
const struct ramc_info *ramc;
for_each_matching_node_and_match(np, ramc_ids, &of_id) {
pm_data.ramc[idx] = of_iomap(np, 0);
if (!pm_data.ramc[idx])
panic(pr_fmt("unable to map ramc[%d] cpu registers\n"), idx);
ramc = of_id->data;
if (!standby)
standby = ramc->idle;
pm_data.memctrl = ramc->memctrl;
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_cpuidle_device.dev.platform_data = 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, pm_data.pmc + AT91_PMC_SCDR);
}
static void at91sam9_idle(void)
{
writel(AT91_PMC_PCK, pm_data.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 void __init at91_pm_backup_init(void)
{
struct gen_pool *sram_pool;
struct device_node *np;
struct platform_device *pdev = NULL;
if ((pm_data.standby_mode != AT91_PM_BACKUP) &&
(pm_data.suspend_mode != AT91_PM_BACKUP))
return;
pm_bu = NULL;
np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-shdwc");
if (!np) {
pr_warn("%s: failed to find shdwc!\n", __func__);
return;
}
pm_data.shdwc = of_iomap(np, 0);
of_node_put(np);
np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-sfrbu");
if (!np) {
pr_warn("%s: failed to find sfrbu!\n", __func__);
goto sfrbu_fail;
}
pm_data.sfrbu = of_iomap(np, 0);
of_node_put(np);
pm_bu = NULL;
np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-securam");
if (!np)
goto securam_fail;
pdev = of_find_device_by_node(np);
of_node_put(np);
if (!pdev) {
pr_warn("%s: failed to find securam device!\n", __func__);
goto securam_fail;
}
sram_pool = gen_pool_get(&pdev->dev, NULL);
if (!sram_pool) {
pr_warn("%s: securam pool unavailable!\n", __func__);
goto securam_fail;
}
pm_bu = (void *)gen_pool_alloc(sram_pool, sizeof(struct at91_pm_bu));
if (!pm_bu) {
pr_warn("%s: unable to alloc securam!\n", __func__);
goto securam_fail;
}
pm_bu->suspended = 0;
pm_bu->canary = __pa_symbol(&canary);
pm_bu->resume = __pa_symbol(cpu_resume);
return;
sfrbu_fail:
iounmap(pm_data.shdwc);
pm_data.shdwc = NULL;
securam_fail:
iounmap(pm_data.sfrbu);
pm_data.sfrbu = NULL;
if (pm_data.standby_mode == AT91_PM_BACKUP)
pm_data.standby_mode = AT91_PM_SLOW_CLOCK;
if (pm_data.suspend_mode == AT91_PM_BACKUP)
pm_data.suspend_mode = AT91_PM_SLOW_CLOCK;
}
struct pmc_info {
unsigned long uhp_udp_mask;
};
static const struct pmc_info pmc_infos[] __initconst = {
{ .uhp_udp_mask = AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP },
{ .uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP },
{ .uhp_udp_mask = AT91SAM926x_PMC_UHP },
};
static const struct of_device_id atmel_pmc_ids[] __initconst = {
{ .compatible = "atmel,at91rm9200-pmc", .data = &pmc_infos[0] },
{ .compatible = "atmel,at91sam9260-pmc", .data = &pmc_infos[1] },
{ .compatible = "atmel,at91sam9g45-pmc", .data = &pmc_infos[2] },
{ .compatible = "atmel,at91sam9n12-pmc", .data = &pmc_infos[1] },
{ .compatible = "atmel,at91sam9x5-pmc", .data = &pmc_infos[1] },
{ .compatible = "atmel,sama5d3-pmc", .data = &pmc_infos[1] },
{ .compatible = "atmel,sama5d2-pmc", .data = &pmc_infos[1] },
{ /* sentinel */ },
};
static void __init at91_pm_init(void (*pm_idle)(void))
{
struct device_node *pmc_np;
const struct of_device_id *of_id;
const struct pmc_info *pmc;
if (at91_cpuidle_device.dev.platform_data)
platform_device_register(&at91_cpuidle_device);
pmc_np = of_find_matching_node_and_match(NULL, atmel_pmc_ids, &of_id);
pm_data.pmc = of_iomap(pmc_np, 0);
if (!pm_data.pmc) {
pr_err("AT91: PM not supported, PMC not found\n");
return;
}
pmc = of_id->data;
pm_data.uhp_udp_mask = pmc->uhp_udp_mask;
if (pm_idle)
arm_pm_idle = pm_idle;
at91_pm_sram_init();
if (at91_suspend_sram_fn) {
suspend_set_ops(&at91_pm_ops);
pr_info("AT91: PM: standby: %s, suspend: %s\n",
pm_modes[pm_data.standby_mode].pattern,
pm_modes[pm_data.suspend_mode].pattern);
} else {
pr_info("AT91: PM not supported, due to no SRAM allocated\n");
}
}
void __init at91rm9200_pm_init(void)
{
if (!IS_ENABLED(CONFIG_SOC_AT91RM9200))
return;
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_init(at91rm9200_idle);
}
void __init at91sam9_pm_init(void)
{
if (!IS_ENABLED(CONFIG_SOC_AT91SAM9))
return;
at91_dt_ramc();
at91_pm_init(at91sam9_idle);
}
void __init sama5_pm_init(void)
{
if (!IS_ENABLED(CONFIG_SOC_SAMA5))
return;
at91_dt_ramc();
at91_pm_init(NULL);
}
void __init sama5d2_pm_init(void)
{
if (!IS_ENABLED(CONFIG_SOC_SAMA5D2))
return;
at91_pm_backup_init();
sama5_pm_init();
}
static int __init at91_pm_modes_select(char *str)
{
char *s;
substring_t args[MAX_OPT_ARGS];
int standby, suspend;
if (!str)
return 0;
s = strsep(&str, ",");
standby = match_token(s, pm_modes, args);
if (standby < 0)
return 0;
suspend = match_token(str, pm_modes, args);
if (suspend < 0)
return 0;
pm_data.standby_mode = standby;
pm_data.suspend_mode = suspend;
return 0;
}
early_param("atmel.pm_modes", at91_pm_modes_select);