arch/arm/mach-at91/pm.c - kernel/msm-4.9 - Gitiles

 /*
  * 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/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);

 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;
 	}
 }

 #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 int __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)" : ""));

 	at91_pm_data.memctrl = AT91_MEMCTRL_SDRAMC;

 	if (of_machine_is_compatible("atmel,at91rm9200")) {
 		/*
 		 * 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;
 	} else if (of_machine_is_compatible("atmel,at91sam9260") ||
 		   of_machine_is_compatible("atmel,at91sam9g20") ||
 		   of_machine_is_compatible("atmel,at91sam9261") ||
 		   of_machine_is_compatible("atmel,at91sam9g10") ||
 		   of_machine_is_compatible("atmel,at91sam9263")) {
 		at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP |
 					    AT91SAM926x_PMC_UDP;
 	} else if (of_machine_is_compatible("atmel,at91sam9g45")) {
 		at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
 	}

 	if (at91_cpuidle_device.dev.platform_data)
 		platform_device_register(&at91_cpuidle_device);

 	suspend_set_ops(&at91_pm_ops);

 	return 0;
 }
 arch_initcall(at91_pm_init);
	/*
	* 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/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);

	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;
	}
	}

	#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 int __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)" : ""));

	at91_pm_data.memctrl = AT91_MEMCTRL_SDRAMC;

	if (of_machine_is_compatible("atmel,at91rm9200")) {
	/*
	* 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;
	} else if (of_machine_is_compatible("atmel,at91sam9260") \|\|
	of_machine_is_compatible("atmel,at91sam9g20") \|\|
	of_machine_is_compatible("atmel,at91sam9261") \|\|
	of_machine_is_compatible("atmel,at91sam9g10") \|\|
	of_machine_is_compatible("atmel,at91sam9263")) {
	at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP \|
	AT91SAM926x_PMC_UDP;
	} else if (of_machine_is_compatible("atmel,at91sam9g45")) {
	at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
	}

	if (at91_cpuidle_device.dev.platform_data)
	platform_device_register(&at91_cpuidle_device);

	suspend_set_ops(&at91_pm_ops);

	return 0;
	}
	arch_initcall(at91_pm_init);