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

/*
 * Atmel AT91 SAM9 & SAMA5 SoCs reset code
 *
 * Copyright (C) 2007 Atmel Corporation.
 * Copyright (C) BitBox Ltd 2010
 * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcosoft.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_address.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>

#include <soc/at91/at91sam9_ddrsdr.h>
#include <soc/at91/at91sam9_sdramc.h>


#define AT91_RSTC_CR	0x00		
/* Reset Controller Control Register */

#define AT91_RSTC_PROCRST	BIT(0)		
/* Processor Reset */

#define AT91_RSTC_PERRST	BIT(2)		
/* Peripheral Reset */

#define AT91_RSTC_EXTRST	BIT(3)		
/* External Reset */

#define AT91_RSTC_KEY		(0xa5 << 24)	
/* KEY Password */


#define AT91_RSTC_SR	0x04		
/* Reset Controller Status Register */

#define AT91_RSTC_URSTS		BIT(0)		
/* User Reset Status */

#define AT91_RSTC_RSTTYP	GENMASK(10, 8)	
/* Reset Type */

#define AT91_RSTC_NRSTL		BIT(16)		
/* NRST Pin Level */

#define AT91_RSTC_SRCMP		BIT(17)		
/* Software Reset Command in Progress */


#define AT91_RSTC_MR	0x08		
/* Reset Controller Mode Register */

#define AT91_RSTC_URSTEN	BIT(0)		
/* User Reset Enable */

#define AT91_RSTC_URSTIEN	BIT(4)		
/* User Reset Interrupt Enable */

#define AT91_RSTC_ERSTL		GENMASK(11, 8)	
/* External Reset Length */


enum reset_type {
	
RESET_TYPE_GENERAL	= 0,
	
RESET_TYPE_WAKEUP	= 1,
	
RESET_TYPE_WATCHDOG	= 2,
	
RESET_TYPE_SOFTWARE	= 3,
	
RESET_TYPE_USER		= 4,
};



static void __iomem *at91_ramc_base[2], *at91_rstc_base;

static struct clk *sclk;

/*
* unless the SDRAM is cleanly shutdown before we hit the
* reset register it can be left driving the data bus and
* killing the chance of a subsequent boot from NAND
*/

static int at91sam9260_restart(struct notifier_block *this, unsigned long mode, void *cmd) { asm volatile( /* Align to cache lines */ ".balign 32\n\t" /* Disable SDRAM accesses */ "str %2, [%0, #" __stringify(AT91_SDRAMC_TR) "]\n\t" /* Power down SDRAM */ "str %3, [%0, #" __stringify(AT91_SDRAMC_LPR) "]\n\t" /* Reset CPU */ "str %4, [%1, #" __stringify(AT91_RSTC_CR) "]\n\t" "b .\n\t" : : "r" (at91_ramc_base[0]), "r" (at91_rstc_base), "r" (1), "r" cpu_to_le32(AT91_SDRAMC_LPCB_POWER_DOWN), "r" cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST)); return NOTIFY_DONE; }

Contributors

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Maxime Ripard2060.61%133.33%
Guenter Roeck1236.36%133.33%
Ben Dooks13.03%133.33%
Total33100.00%3100.00%


static int at91sam9g45_restart(struct notifier_block *this, unsigned long mode, void *cmd) { asm volatile( /* * Test wether we have a second RAM controller to care * about. * * First, test that we can dereference the virtual address. */ "cmp %1, #0\n\t" "beq 1f\n\t" /* Then, test that the RAM controller is enabled */ "ldr r0, [%1]\n\t" "cmp r0, #0\n\t" /* Align to cache lines */ ".balign 32\n\t" /* Disable SDRAM0 accesses */ "1: str %3, [%0, #" __stringify(AT91_DDRSDRC_RTR) "]\n\t" /* Power down SDRAM0 */ " str %4, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t" /* Disable SDRAM1 accesses */ " strne %3, [%1, #" __stringify(AT91_DDRSDRC_RTR) "]\n\t" /* Power down SDRAM1 */ " strne %4, [%1, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t" /* Reset CPU */ " str %5, [%2, #" __stringify(AT91_RSTC_CR) "]\n\t" " b .\n\t" : : "r" (at91_ramc_base[0]), "r" (at91_ramc_base[1]), "r" (at91_rstc_base), "r" (1), "r" cpu_to_le32(AT91_DDRSDRC_LPCB_POWER_DOWN), "r" cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST) : "r0"); return NOTIFY_DONE; }

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PersonTokensPropCommitsCommitProp
Maxime Ripard2663.41%125.00%
Guenter Roeck1229.27%125.00%
Alexandre Belloni24.88%125.00%
Ben Dooks12.44%125.00%
Total41100.00%4100.00%


static int sama5d3_restart(struct notifier_block *this, unsigned long mode, void *cmd) { writel(cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST), at91_rstc_base); return NOTIFY_DONE; }

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Josh Wu36100.00%1100.00%
Total36100.00%1100.00%


static int samx7_restart(struct notifier_block *this, unsigned long mode, void *cmd) { writel(cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PROCRST), at91_rstc_base); return NOTIFY_DONE; }

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Szemző András34100.00%1100.00%
Total34100.00%1100.00%


static void __init at91_reset_status(struct platform_device *pdev) { u32 reg = readl(at91_rstc_base + AT91_RSTC_SR); char *reason; switch ((reg & AT91_RSTC_RSTTYP) >> 8) { case RESET_TYPE_GENERAL: reason = "general reset"; break; case RESET_TYPE_WAKEUP: reason = "wakeup"; break; case RESET_TYPE_WATCHDOG: reason = "watchdog reset"; break; case RESET_TYPE_SOFTWARE: reason = "software reset"; break; case RESET_TYPE_USER: reason = "user reset"; break; default: reason = "unknown reset"; break; } pr_info("AT91: Starting after %s\n", reason); }

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Maxime Ripard91100.00%1100.00%
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static const struct of_device_id at91_ramc_of_match[] = { { .compatible = "atmel,at91sam9260-sdramc", }, { .compatible = "atmel,at91sam9g45-ddramc", }, { /* sentinel */ } }; static const struct of_device_id at91_reset_of_match[] = { { .compatible = "atmel,at91sam9260-rstc", .data = at91sam9260_restart }, { .compatible = "atmel,at91sam9g45-rstc", .data = at91sam9g45_restart }, { .compatible = "atmel,sama5d3-rstc", .data = sama5d3_restart }, { .compatible = "atmel,samx7-rstc", .data = samx7_restart }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, at91_reset_of_match); static struct notifier_block at91_restart_nb = { .priority = 192, };
static int __init at91_reset_probe(struct platform_device *pdev) { const struct of_device_id *match; struct device_node *np; int ret, idx = 0; at91_rstc_base = of_iomap(pdev->dev.of_node, 0); if (!at91_rstc_base) { dev_err(&pdev->dev, "Could not map reset controller address\n"); return -ENODEV; } if (!of_device_is_compatible(pdev->dev.of_node, "atmel,sama5d3-rstc")) { /* we need to shutdown the ddr controller, so get ramc base */ for_each_matching_node(np, at91_ramc_of_match) { at91_ramc_base[idx] = of_iomap(np, 0); if (!at91_ramc_base[idx]) { dev_err(&pdev->dev, "Could not map ram controller address\n"); of_node_put(np); return -ENODEV; } idx++; } } match = of_match_node(at91_reset_of_match, pdev->dev.of_node); at91_restart_nb.notifier_call = match->data; 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; } ret = register_restart_handler(&at91_restart_nb); if (ret) { clk_disable_unprepare(sclk); return ret; } at91_reset_status(pdev); return 0; }

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Maxime Ripard14260.43%114.29%
Alexandre Belloni6326.81%342.86%
Josh Wu177.23%114.29%
Guenter Roeck83.40%114.29%
Julia Lawall52.13%114.29%
Total235100.00%7100.00%


static int __exit at91_reset_remove(struct platform_device *pdev) { unregister_restart_handler(&at91_restart_nb); clk_disable_unprepare(sclk); return 0; }

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Alexandre Belloni26100.00%2100.00%
Total26100.00%2100.00%

static struct platform_driver at91_reset_driver = { .remove = __exit_p(at91_reset_remove), .driver = { .name = "at91-reset", .of_match_table = at91_reset_of_match, }, }; module_platform_driver_probe(at91_reset_driver, at91_reset_probe); MODULE_AUTHOR("Atmel Corporation"); MODULE_DESCRIPTION("Reset driver for Atmel SoCs"); MODULE_LICENSE("GPL v2");

Overall Contributors

PersonTokensPropCommitsCommitProp
Maxime Ripard49662.55%17.14%
Alexandre Belloni12515.76%535.71%
Josh Wu658.20%17.14%
Szemző András465.80%17.14%
Guenter Roeck445.55%17.14%
Javier Martinez Canillas70.88%17.14%
Julia Lawall50.63%17.14%
Ben Dooks20.25%17.14%
Fabian Frederick20.25%17.14%
Nicolas Ferre10.13%17.14%
Total793100.00%14100.00%
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