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Commit ae499f0f authored by Maxime Ripard's avatar Maxime Ripard
Browse files

power: reset: Add AT91 poweroff driver 



Add a driver to handle the shutdown of the Atmel SoCs. This code used to be
(and still is) in arch/arm/mach-at91. We didn't remove it yet so that we can
convert all the boards to using this driver, before removing it entirely in a
separate patch.

Signed-off-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
parent ecfe64d8

drivers/power/reset/Kconfig

+8 −0
Original line number Original line Diff line number Diff line
@@ -14,6 +14,14 @@ config POWER_RESET_AS3722 
	help

	help

	  This driver supports turning off board via a ams AS3722 power-off.

	  This driver supports turning off board via a ams AS3722 power-off.





config POWER_RESET_AT91_POWEROFF

	bool "Atmel AT91 poweroff driver"

	depends on MACH_AT91

	default SOC_AT91SAM9 || SOC_SAMA5

	help

	  This driver supports poweroff for Atmel AT91SAM9 and SAMA5

	  SoCs



config POWER_RESET_AT91_RESET

config POWER_RESET_AT91_RESET

	bool "Atmel AT91 reset driver"

	bool "Atmel AT91 reset driver"

	depends on MACH_AT91

	depends on MACH_AT91

drivers/power/reset/Makefile

+1 −0
Original line number Original line Diff line number Diff line 
obj-$(CONFIG_POWER_RESET_AS3722) += as3722-poweroff.o

obj-$(CONFIG_POWER_RESET_AS3722) += as3722-poweroff.o

obj-$(CONFIG_POWER_RESET_AT91_POWEROFF) += at91-poweroff.o

obj-$(CONFIG_POWER_RESET_AT91_RESET) += at91-reset.o

obj-$(CONFIG_POWER_RESET_AT91_RESET) += at91-reset.o

obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o

obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o

obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o

obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o

drivers/power/reset/at91-poweroff.c

0 → 100644
+156 −0
Original line number Original line Diff line number Diff line 
/*

 * Atmel AT91 SAM9 SoCs reset code

 *

 * Copyright (C) 2007 Atmel Corporation.

 * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

 * Copyright (C) 2014 Free Electrons

 *

 * This file is licensed under the terms of the GNU General Public

 * License version 2.  This program is licensed "as is" without any

 * warranty of any kind, whether express or implied.

 */



#include <linux/io.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/printk.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 */



#define AT91_SHDW_MR	0x04		/* Shut Down Mode Register */

#define AT91_SHDW_WKMODE0	GENMASK(2, 0)		/* Wake-up 0 Mode Selection */

#define AT91_SHDW_CPTWK0_MAX	0xf			/* Maximum Counter On Wake Up 0 */

#define AT91_SHDW_CPTWK0	(AT91_SHDW_CPTWK0_MAX << 4) /* Counter On Wake Up 0 */

#define AT91_SHDW_CPTWK0_(x)	((x) << 4)

#define AT91_SHDW_RTTWKEN	BIT(16)			/* Real Time Timer Wake-up Enable */

#define AT91_SHDW_RTCWKEN	BIT(17)			/* Real Time Clock Wake-up Enable */



#define AT91_SHDW_SR	0x08		/* Shut Down Status Register */

#define AT91_SHDW_WAKEUP0	BIT(0)			/* Wake-up 0 Status */

#define AT91_SHDW_RTTWK		BIT(16)			/* Real-time Timer Wake-up */

#define AT91_SHDW_RTCWK		BIT(17)			/* Real-time Clock Wake-up [SAM9RL] */



enum wakeup_type {

	AT91_SHDW_WKMODE0_NONE		= 0,

	AT91_SHDW_WKMODE0_HIGH		= 1,

	AT91_SHDW_WKMODE0_LOW		= 2,

	AT91_SHDW_WKMODE0_ANYLEVEL	= 3,

};



static const char *shdwc_wakeup_modes[] = {

	[AT91_SHDW_WKMODE0_NONE]	= "none",

	[AT91_SHDW_WKMODE0_HIGH]	= "high",

	[AT91_SHDW_WKMODE0_LOW]		= "low",

	[AT91_SHDW_WKMODE0_ANYLEVEL]	= "any",

};



static void __iomem *at91_shdwc_base;



static void __init at91_wakeup_status(void)

{

	u32 reg = readl(at91_shdwc_base);

	char *reason = "unknown";



	/* Simple power-on, just bail out */

	if (!reg)

		return;



	if (reg & AT91_SHDW_RTTWK)

		reason = "RTT";

	else if (reg & AT91_SHDW_RTCWK)

		reason = "RTC";



	pr_info("AT91: Wake-Up source: %s\n", reason);

}



static void at91_poweroff(void)

{

	writel(AT91_SHDW_KEY | AT91_SHDW_SHDW, at91_shdwc_base + AT91_SHDW_CR);

}



const enum wakeup_type at91_poweroff_get_wakeup_mode(struct device_node *np)

{

	const char *pm;

	int err, i;



	err = of_property_read_string(np, "atmel,wakeup-mode", &pm);

	if (err < 0)

		return AT91_SHDW_WKMODE0_ANYLEVEL;



	for (i = 0; i < ARRAY_SIZE(shdwc_wakeup_modes); i++)

		if (!strcasecmp(pm, shdwc_wakeup_modes[i]))

			return i;



	return -ENODEV;

}



static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)

{

	struct device_node *np = pdev->dev.of_node;

	enum wakeup_type wakeup_mode;

	u32 mode = 0, tmp;



	wakeup_mode = at91_poweroff_get_wakeup_mode(np);

	if (wakeup_mode < 0) {

		dev_warn(&pdev->dev, "shdwc unknown wakeup mode\n");

		return;

	}



	if (!of_property_read_u32(np, "atmel,wakeup-counter", &tmp)) {

		if (tmp > AT91_SHDW_CPTWK0_MAX) {

			dev_warn(&pdev->dev,

				 "shdwc wakeup counter 0x%x > 0x%x reduce it to 0x%x\n",

				 tmp, AT91_SHDW_CPTWK0_MAX, AT91_SHDW_CPTWK0_MAX);

			tmp = AT91_SHDW_CPTWK0_MAX;

		}

		mode |= AT91_SHDW_CPTWK0_(tmp);

	}



	if (of_property_read_bool(np, "atmel,wakeup-rtc-timer"))

			mode |= AT91_SHDW_RTCWKEN;



	if (of_property_read_bool(np, "atmel,wakeup-rtt-timer"))

			mode |= AT91_SHDW_RTTWKEN;



	writel(wakeup_mode | mode, at91_shdwc_base + AT91_SHDW_MR);

}



static int at91_poweroff_probe(struct platform_device *pdev)

{

	struct resource *res;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(at91_shdwc_base)) {

		dev_err(&pdev->dev, "Could not map reset controller address\n");

		return PTR_ERR(at91_shdwc_base);

	}



	at91_wakeup_status();



	if (pdev->dev.of_node)

		at91_poweroff_dt_set_wakeup_mode(pdev);



	pm_power_off = at91_poweroff;



	return 0;

}



static struct of_device_id at91_poweroff_of_match[] = {

	{ .compatible = "atmel,at91sam9260-shdwc", },

	{ .compatible = "atmel,at91sam9rl-shdwc", },

	{ .compatible = "atmel,at91sam9x5-shdwc", },

	{ /*sentinel*/ }

};



static struct platform_driver at91_poweroff_driver = {

	.probe = at91_poweroff_probe,

	.driver = {

		.name = "at91-poweroff",

		.of_match_table = at91_poweroff_of_match,

	},

};

module_platform_driver(at91_poweroff_driver);