From ab3f09fe16d158cb4f84e558c61ec5d6d601f2e0 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Mon, 4 Jan 2016 20:36:38 +0100 Subject: [PATCH] watchdog: add MT7621 watchdog support This patch adds support for the watchdog core found on newer MediaTek Wifi SoCs MT7621 and MT7628. There is no symbol for MT7628 as it is a subtype of MT7620 so we depend on that instead. Signed-off-by: John Crispin Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- .../bindings/watchdog/mt7621-wdt.txt | 12 ++ drivers/watchdog/Kconfig | 7 + drivers/watchdog/Makefile | 1 + drivers/watchdog/mt7621_wdt.c | 186 ++++++++++++++++++ 4 files changed, 206 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt create mode 100644 drivers/watchdog/mt7621_wdt.c diff --git a/Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt b/Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt new file mode 100644 index 000000000000..c15ef0ef609f --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt @@ -0,0 +1,12 @@ +Ralink Watchdog Timers + +Required properties: +- compatible: must be "mediatek,mt7621-wdt" +- reg: physical base address of the controller and length of the register range + +Example: + + watchdog@100 { + compatible = "mediatek,mt7621-wdt"; + reg = <0x100 0x10>; + }; diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index afb7f91795cb..4f0e7be0da34 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1403,6 +1403,13 @@ 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 Mediatek/Ralink MT7621/8 SoC Watchdog Timer. + # PARISC Architecture # POWERPC Architecture diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 2d203fc3cfdb..f566753256ab 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -152,6 +152,7 @@ octeon-wdt-y := octeon-wdt-main.o octeon-wdt-nmi.o obj-$(CONFIG_LANTIQ_WDT) += lantiq_wdt.o obj-$(CONFIG_RALINK_WDT) += rt2880_wdt.o obj-$(CONFIG_IMGPDC_WDT) += imgpdc_wdt.o +obj-$(CONFIG_MT7621_WDT) += mt7621_wdt.o # PARISC Architecture diff --git a/drivers/watchdog/mt7621_wdt.c b/drivers/watchdog/mt7621_wdt.c new file mode 100644 index 000000000000..4a2290f900a8 --- /dev/null +++ b/drivers/watchdog/mt7621_wdt.c @@ -0,0 +1,186 @@ +/* + * Ralink MT7621/MT7628 built-in hardware watchdog timer + * + * Copyright (C) 2014 John Crispin + * + * This driver was based on: drivers/watchdog/rt2880_wdt.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 +#include +#include +#include +#include +#include +#include + +#include + +#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) +#define TMR1CTL_PRESCALE_SHIFT 16 + +static void __iomem *mt7621_wdt_base; +static struct reset_control *mt7621_wdt_reset; + +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, mt7621_wdt_base + reg); +} + +static inline u32 rt_wdt_r32(unsigned reg) +{ + return ioread32(mt7621_wdt_base + reg); +} + +static int mt7621_wdt_ping(struct watchdog_device *w) +{ + rt_wdt_w32(TIMER_REG_TMRSTAT, TMR1CTL_RESTART); + + return 0; +} + +static int mt7621_wdt_set_timeout(struct watchdog_device *w, unsigned int t) +{ + w->timeout = t; + rt_wdt_w32(TIMER_REG_TMR1LOAD, t * 1000); + mt7621_wdt_ping(w); + + return 0; +} + +static int mt7621_wdt_start(struct watchdog_device *w) +{ + u32 t; + + /* set the prescaler to 1ms == 1000us */ + rt_wdt_w32(TIMER_REG_TMR1CTL, 1000 << TMR1CTL_PRESCALE_SHIFT); + + mt7621_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 mt7621_wdt_stop(struct watchdog_device *w) +{ + u32 t; + + mt7621_wdt_ping(w); + + t = rt_wdt_r32(TIMER_REG_TMR1CTL); + t &= ~TMR1CTL_ENABLE; + rt_wdt_w32(TIMER_REG_TMR1CTL, t); + + return 0; +} + +static int mt7621_wdt_bootcause(void) +{ + if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE) + return WDIOF_CARDRESET; + + return 0; +} + +static struct watchdog_info mt7621_wdt_info = { + .identity = "Mediatek Watchdog", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, +}; + +static struct watchdog_ops mt7621_wdt_ops = { + .owner = THIS_MODULE, + .start = mt7621_wdt_start, + .stop = mt7621_wdt_stop, + .ping = mt7621_wdt_ping, + .set_timeout = mt7621_wdt_set_timeout, +}; + +static struct watchdog_device mt7621_wdt_dev = { + .info = &mt7621_wdt_info, + .ops = &mt7621_wdt_ops, + .min_timeout = 1, + .max_timeout = 0xfffful / 1000, +}; + +static int mt7621_wdt_probe(struct platform_device *pdev) +{ + struct resource *res; + int ret; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + mt7621_wdt_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(mt7621_wdt_base)) + return PTR_ERR(mt7621_wdt_base); + + mt7621_wdt_reset = devm_reset_control_get(&pdev->dev, NULL); + if (!IS_ERR(mt7621_wdt_reset)) + reset_control_deassert(mt7621_wdt_reset); + + mt7621_wdt_dev.dev = &pdev->dev; + mt7621_wdt_dev.bootstatus = mt7621_wdt_bootcause(); + + watchdog_init_timeout(&mt7621_wdt_dev, mt7621_wdt_dev.max_timeout, + &pdev->dev); + watchdog_set_nowayout(&mt7621_wdt_dev, nowayout); + + ret = watchdog_register_device(&mt7621_wdt_dev); + + return 0; +} + +static int mt7621_wdt_remove(struct platform_device *pdev) +{ + watchdog_unregister_device(&mt7621_wdt_dev); + + return 0; +} + +static void mt7621_wdt_shutdown(struct platform_device *pdev) +{ + mt7621_wdt_stop(&mt7621_wdt_dev); +} + +static const struct of_device_id mt7621_wdt_match[] = { + { .compatible = "mediatek,mt7621-wdt" }, + {}, +}; +MODULE_DEVICE_TABLE(of, mt7621_wdt_match); + +static struct platform_driver mt7621_wdt_driver = { + .probe = mt7621_wdt_probe, + .remove = mt7621_wdt_remove, + .shutdown = mt7621_wdt_shutdown, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = mt7621_wdt_match, + }, +}; + +module_platform_driver(mt7621_wdt_driver); + +MODULE_DESCRIPTION("MediaTek MT762x hardware watchdog driver"); +MODULE_AUTHOR("John Crispin