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Release 4.14 drivers/power/reset/at91-poweroff.c

/*
 * 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/clk.h>
#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 */


#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 struct clk *sclk;

static void __iomem *mpddrc_base;


static void __init at91_wakeup_status(void) { u32 reg = readl(at91_shdwc_base + AT91_SHDW_SR); 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); }

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static void at91_poweroff(void) { writel(AT91_SHDW_KEY | AT91_SHDW_SHDW, at91_shdwc_base + AT91_SHDW_CR); }

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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) : "r6"); }

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static int at91_poweroff_get_wakeup_mode(struct device_node *np) { const char *pm; unsigned int i; int err; 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; }

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static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; int 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); }

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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); 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); } sclk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(sclk)) return PTR_ERR(sclk); ret = clk_prepare_enable(sclk); if (ret) { dev_err(&pdev->dev, "Could not enable slow clock\n"); return ret; } at91_wakeup_status(); if (pdev->dev.of_node) at91_poweroff_dt_set_wakeup_mode(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; }

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static int __exit at91_poweroff_remove(struct platform_device *pdev) { if (pm_power_off == at91_poweroff || pm_power_off == at91_lpddr_poweroff) pm_power_off = NULL; clk_disable_unprepare(sclk); return 0; }

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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", }, { .compatible = "atmel,at91sam9x5-shdwc", }, { /*sentinel*/ } }; MODULE_DEVICE_TABLE(of, at91_poweroff_of_match); static struct platform_driver at91_poweroff_driver = { .remove = __exit_p(at91_poweroff_remove), .driver = { .name = "at91-poweroff", .of_match_table = at91_poweroff_of_match, }, }; module_platform_driver_probe(at91_poweroff_driver, at91_poweroff_probe); MODULE_AUTHOR("Atmel Corporation"); MODULE_DESCRIPTION("Shutdown driver for Atmel SoCs"); MODULE_LICENSE("GPL v2");

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