power: reset: at91-poweroff: timely shutdown LPDDR memories (0b040874) · Commits · 戴 / test

drivers/power/reset/Kconfig

+1 −1

Original line number	Diff line number	Diff line
		@@ -32,7 +32,7 @@ config POWER_RESET_AT91_RESET

		config POWER_RESET_AT91_SAMA5D2_SHDWC
		tristate "Atmel AT91 SAMA5D2-Compatible shutdown controller driver"
		depends on ARCH_AT91 \|\| COMPILE_TEST
		depends on ARCH_AT91
		default SOC_SAMA5
		help
		This driver supports the alternate shutdown controller for some Atmel

drivers/power/reset/at91-poweroff.c

+53 −1

Original line number	Diff line number	Diff line
		@@ -14,9 +14,12 @@
		#include <linux/io.h>
		#include <linux/module.h>
		#include <linux/of.h>
		#include <linux/of_address.h>
		#include <linux/platform_device.h>
		#include <linux/printk.h>

		#include <soc/at91/at91sam9_ddrsdr.h>

		#define AT91_SHDW_CR 0x00 /* Shut Down Control Register */
		#define AT91_SHDW_SHDW BIT(0) /* Shut Down command */
		#define AT91_SHDW_KEY (0xa5 << 24) /* KEY Password */
		@@ -50,6 +53,7 @@ static const char *shdwc_wakeup_modes[] = {

		static void __iomem *at91_shdwc_base;
		static struct clk *sclk;
		static void __iomem *mpddrc_base;

		static void __init at91_wakeup_status(void)
		{
		@@ -73,6 +77,29 @@ static void at91_poweroff(void)
		writel(AT91_SHDW_KEY \| AT91_SHDW_SHDW, at91_shdwc_base + AT91_SHDW_CR);
		}

		static void at91_lpddr_poweroff(void)
		{
		asm volatile(
		/* Align to cache lines */
		".balign 32\n\t"

		/* Ensure AT91_SHDW_CR is in the TLB by reading it */
		" ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"

		/* Power down SDRAM0 */
		" str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
		/* Shutdown CPU */
		" str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"

		" b .\n\t"
		:
		: "r" (mpddrc_base),
		"r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
		"r" (at91_shdwc_base),
		"r" cpu_to_le32(AT91_SHDW_KEY \| AT91_SHDW_SHDW)
		: "r0");
		}

		static int at91_poweroff_get_wakeup_mode(struct device_node *np)
		{
		const char *pm;
		@@ -124,6 +151,8 @@ static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)
		static int __init at91_poweroff_probe(struct platform_device *pdev)
		{
		struct resource *res;
		struct device_node *np;
		u32 ddr_type;
		int ret;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		@@ -150,12 +179,30 @@ static int __init at91_poweroff_probe(struct platform_device *pdev)

		pm_power_off = at91_poweroff;

		np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc");
		if (!np)
		return 0;

		mpddrc_base = of_iomap(np, 0);
		of_node_put(np);

		if (!mpddrc_base)
		return 0;

		ddr_type = readl(mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD;
		if ((ddr_type == AT91_DDRSDRC_MD_LPDDR2) \|\|
		(ddr_type == AT91_DDRSDRC_MD_LPDDR3))
		pm_power_off = at91_lpddr_poweroff;
		else
		iounmap(mpddrc_base);

		return 0;
		}

		static int __exit at91_poweroff_remove(struct platform_device *pdev)
		{
		if (pm_power_off == at91_poweroff)
		if (pm_power_off == at91_poweroff \|\|
		pm_power_off == at91_lpddr_poweroff)
		pm_power_off = NULL;

		clk_disable_unprepare(sclk);
		@@ -163,6 +210,11 @@ static int __exit at91_poweroff_remove(struct platform_device *pdev)
		return 0;
		}

		static const struct of_device_id at91_ramc_of_match[] = {
		{ .compatible = "atmel,sama5d3-ddramc", },
		{ /* sentinel */ }
		};

		static const struct of_device_id at91_poweroff_of_match[] = {
		{ .compatible = "atmel,at91sam9260-shdwc", },
		{ .compatible = "atmel,at91sam9rl-shdwc", },

drivers/power/reset/at91-sama5d2_shdwc.c

+48 −1

Original line number	Diff line number	Diff line
		@@ -22,9 +22,12 @@
		#include <linux/io.h>
		#include <linux/module.h>
		#include <linux/of.h>
		#include <linux/of_address.h>
		#include <linux/platform_device.h>
		#include <linux/printk.h>

		#include <soc/at91/at91sam9_ddrsdr.h>

		#define SLOW_CLOCK_FREQ 32768

		#define AT91_SHDW_CR 0x00 /* Shut Down Control Register */
		@@ -75,6 +78,7 @@ struct shdwc {
		*/
		static struct shdwc *at91_shdwc;
		static struct clk *sclk;
		static void __iomem *mpddrc_base;

		static const unsigned long long sdwc_dbc_period[] = {
		0, 3, 32, 512, 4096, 32768,
		@@ -108,6 +112,29 @@ static void at91_poweroff(void)
		at91_shdwc->at91_shdwc_base + AT91_SHDW_CR);
		}

		static void at91_lpddr_poweroff(void)
		{
		asm volatile(
		/* Align to cache lines */
		".balign 32\n\t"

		/* Ensure AT91_SHDW_CR is in the TLB by reading it */
		" ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"

		/* Power down SDRAM0 */
		" str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
		/* Shutdown CPU */
		" str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"

		" b .\n\t"
		:
		: "r" (mpddrc_base),
		"r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
		"r" (at91_shdwc->at91_shdwc_base),
		"r" cpu_to_le32(AT91_SHDW_KEY \| AT91_SHDW_SHDW)
		: "r0");
		}

		static u32 at91_shdwc_debouncer_value(struct platform_device *pdev,
		u32 in_period_us)
		{
		@@ -212,6 +239,8 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
		{
		struct resource *res;
		const struct of_device_id *match;
		struct device_node *np;
		u32 ddr_type;
		int ret;

		if (!pdev->dev.of_node)
		@@ -249,6 +278,23 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)

		pm_power_off = at91_poweroff;

		np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc");
		if (!np)
		return 0;

		mpddrc_base = of_iomap(np, 0);
		of_node_put(np);

		if (!mpddrc_base)
		return 0;

		ddr_type = readl(mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD;
		if ((ddr_type == AT91_DDRSDRC_MD_LPDDR2) \|\|
		(ddr_type == AT91_DDRSDRC_MD_LPDDR3))
		pm_power_off = at91_lpddr_poweroff;
		else
		iounmap(mpddrc_base);

		return 0;
		}

		@@ -256,7 +302,8 @@ static int __exit at91_shdwc_remove(struct platform_device *pdev)
		{
		struct shdwc *shdw = platform_get_drvdata(pdev);

		if (pm_power_off == at91_poweroff)
		if (pm_power_off == at91_poweroff \|\|
		pm_power_off == at91_lpddr_poweroff)
		pm_power_off = NULL;

		/* Reset values to disable wake-up features */

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