From 77fe64de72317c0e090d82056e7a6a073f2972b4 Mon Sep 17 00:00:00 2001 From: John Crispin <blogic@openwrt.org> Date: Sun, 16 Mar 2014 05:24:42 +0000 Subject: [PATCH 49/53] watchdog: add MT7621 support Signed-off-by: John Crispin <blogic@openwrt.org> --- drivers/watchdog/Kconfig | 7 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/mt7621_wdt.c | 185 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 193 insertions(+) create mode 100644 drivers/watchdog/mt7621_wdt.c --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1345,6 +1345,13 @@ config RALINK_WDT help Hardware driver for the Ralink SoC Watchdog Timer. +config MT7621_WDT + tristate "Mediatek SoC watchdog" + select WATCHDOG_CORE + depends on SOC_MT7620 || SOC_MT7621 + help + Hardware driver for the Ralink SoC Watchdog Timer. + # PARISC Architecture # POWERPC Architecture --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -69,6 +69,7 @@ obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_w obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o +obj-$(CONFIG_MT7621_WDT) += mt7621_wdt.o # AVR32 Architecture obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o --- /dev/null +++ b/drivers/watchdog/mt7621_wdt.c @@ -0,0 +1,185 @@ +/* + * Ralink RT288x/RT3xxx/MT76xx built-in hardware watchdog timer + * + * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org> + * Copyright (C) 2013 John Crispin <blogic@openwrt.org> + * + * This driver was based on: drivers/watchdog/softdog.c + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include <linux/clk.h> +#include <linux/reset.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/watchdog.h> +#include <linux/miscdevice.h> +#include <linux/moduleparam.h> +#include <linux/platform_device.h> + +#include <asm/mach-ralink/ralink_regs.h> + +#define SYSC_RSTSTAT 0x38 +#define WDT_RST_CAUSE BIT(1) + +#define RALINK_WDT_TIMEOUT 30 + +#define TIMER_REG_TMRSTAT 0x00 +#define TIMER_REG_TMR1LOAD 0x24 +#define TIMER_REG_TMR1CTL 0x20 + +#define TMR1CTL_ENABLE BIT(7) +#define TMR1CTL_RESTART BIT(9) + +static void __iomem *mt762x_wdt_base; + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, + "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +static inline void rt_wdt_w32(unsigned reg, u32 val) +{ + iowrite32(val, mt762x_wdt_base + reg); +} + +static inline u32 rt_wdt_r32(unsigned reg) +{ + return ioread32(mt762x_wdt_base + reg); +} + +static int mt762x_wdt_ping(struct watchdog_device *w) +{ + rt_wdt_w32(TIMER_REG_TMRSTAT, TMR1CTL_RESTART); + + return 0; +} + +static int mt762x_wdt_set_timeout(struct watchdog_device *w, unsigned int t) +{ + w->timeout = t; + rt_wdt_w32(TIMER_REG_TMR1LOAD, t * 1000); + mt762x_wdt_ping(w); + + return 0; +} + +static int mt762x_wdt_start(struct watchdog_device *w) +{ + u32 t; + + rt_wdt_w32(TIMER_REG_TMR1CTL, 1000 << 16); + mt762x_wdt_set_timeout(w, w->timeout); + + t = rt_wdt_r32(TIMER_REG_TMR1CTL); + t |= TMR1CTL_ENABLE; + rt_wdt_w32(TIMER_REG_TMR1CTL, t); + + return 0; +} + +static int mt762x_wdt_stop(struct watchdog_device *w) +{ + u32 t; + + mt762x_wdt_ping(w); + + t = rt_wdt_r32(TIMER_REG_TMR1CTL); + t &= ~TMR1CTL_ENABLE; + rt_wdt_w32(TIMER_REG_TMR1CTL, t); + + return 0; +} + +static int mt762x_wdt_bootcause(void) +{ + if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE) + return WDIOF_CARDRESET; + + return 0; +} + +static struct watchdog_info mt762x_wdt_info = { + .identity = "Mediatek Watchdog", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, +}; + +static struct watchdog_ops mt762x_wdt_ops = { + .owner = THIS_MODULE, + .start = mt762x_wdt_start, + .stop = mt762x_wdt_stop, + .ping = mt762x_wdt_ping, + .set_timeout = mt762x_wdt_set_timeout, +}; + +static struct watchdog_device mt762x_wdt_dev = { + .info = &mt762x_wdt_info, + .ops = &mt762x_wdt_ops, + .min_timeout = 1, +}; + +static int mt762x_wdt_probe(struct platform_device *pdev) +{ + struct resource *res; + int ret; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + mt762x_wdt_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(mt762x_wdt_base)) + return PTR_ERR(mt762x_wdt_base); + + device_reset(&pdev->dev); + + mt762x_wdt_dev.dev = &pdev->dev; + mt762x_wdt_dev.bootstatus = mt762x_wdt_bootcause(); + mt762x_wdt_dev.max_timeout = (0xfffful / 1000); + mt762x_wdt_dev.timeout = mt762x_wdt_dev.max_timeout; + + watchdog_set_nowayout(&mt762x_wdt_dev, nowayout); + + ret = watchdog_register_device(&mt762x_wdt_dev); + if (!ret) + dev_info(&pdev->dev, "Initialized\n"); + + return 0; +} + +static int mt762x_wdt_remove(struct platform_device *pdev) +{ + watchdog_unregister_device(&mt762x_wdt_dev); + + return 0; +} + +static void mt762x_wdt_shutdown(struct platform_device *pdev) +{ + mt762x_wdt_stop(&mt762x_wdt_dev); +} + +static const struct of_device_id mt762x_wdt_match[] = { + { .compatible = "mtk,mt7621-wdt" }, + {}, +}; +MODULE_DEVICE_TABLE(of, mt762x_wdt_match); + +static struct platform_driver mt762x_wdt_driver = { + .probe = mt762x_wdt_probe, + .remove = mt762x_wdt_remove, + .shutdown = mt762x_wdt_shutdown, + .driver = { + .name = KBUILD_MODNAME, + .owner = THIS_MODULE, + .of_match_table = mt762x_wdt_match, + }, +}; + +module_platform_driver(mt762x_wdt_driver); + +MODULE_DESCRIPTION("MediaTek MT762x hardware watchdog driver"); +MODULE_AUTHOR("John Crispin <blogic@openwrt.org"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);