From 14c1b064274d28cf88113a685c58374a515f3018 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Mon, 22 Apr 2013 23:23:07 +0200 Subject: [PATCH 137/137] watchdog: adds ralink wdt Adds the watchdog driver for ralink SoC. Signed-off-by: John Crispin --- drivers/watchdog/Kconfig | 6 + drivers/watchdog/Makefile | 1 + drivers/watchdog/ralink_wdt.c | 352 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 359 insertions(+) create mode 100644 drivers/watchdog/ralink_wdt.c --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1077,6 +1077,12 @@ config LANTIQ_WDT help Hardware driver for the Lantiq SoC Watchdog Timer. +config RALINK_WDT + tristate "Ralink SoC watchdog" + depends on RALINK + help + Hardware driver for the Ralink SoC Watchdog Timer. + # PARISC Architecture # POWERPC Architecture --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -132,6 +132,7 @@ obj-$(CONFIG_TXX9_WDT) += txx9wdt.o obj-$(CONFIG_OCTEON_WDT) += octeon-wdt.o octeon-wdt-y := octeon-wdt-main.o octeon-wdt-nmi.o obj-$(CONFIG_LANTIQ_WDT) += lantiq_wdt.o +obj-$(CONFIG_RALINK_WDT) += ralink_wdt.o # PARISC Architecture --- /dev/null +++ b/drivers/watchdog/ralink_wdt.c @@ -0,0 +1,352 @@ +/* + * Ralink RT288X/RT305X built-in hardware watchdog timer + * + * Copyright (C) 2011 Gabor Juhos + * + * This driver was based on: drivers/watchdog/ixp4xx_wdt.c + * Author: Deepak Saxena + * Copyright 2004 (c) MontaVista, Software, Inc. + * + * which again was based on sa1100 driver, + * Copyright (C) 2000 Oleg Drokin + * + * parts of the driver are based on Ralink's 2.6.21 BSP + * + * 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 +#include +#include +#include +#include +#include + +#define DRIVER_NAME "ralink-wdt" + +#define RALINK_WDT_TIMEOUT 30 /* seconds */ +#define RALINK_WDT_PRESCALE 65536 + +#define TIMER_REG_TMR1LOAD 0x00 +#define TIMER_REG_TMR1CTL 0x08 + +#define TMRSTAT_TMR1RST BIT(5) + +#define TMR1CTL_ENABLE BIT(7) +#define TMR1CTL_MODE_SHIFT 4 +#define TMR1CTL_MODE_MASK 0x3 +#define TMR1CTL_MODE_FREE_RUNNING 0x0 +#define TMR1CTL_MODE_PERIODIC 0x1 +#define TMR1CTL_MODE_TIMEOUT 0x2 +#define TMR1CTL_MODE_WDT 0x3 +#define TMR1CTL_PRESCALE_MASK 0xf +#define TMR1CTL_PRESCALE_65536 0xf + +static int nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +static int ralink_wdt_timeout = RALINK_WDT_TIMEOUT; +module_param_named(timeout, ralink_wdt_timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, 0 means use maximum " + "(default=" __MODULE_STRING(RALINK_WDT_TIMEOUT) "s)"); + +static unsigned long ralink_wdt_flags; + +#define WDT_FLAGS_BUSY 0 +#define WDT_FLAGS_EXPECT_CLOSE 1 + +static struct clk *ralink_wdt_clk; +static unsigned long ralink_wdt_freq; +static int ralink_wdt_max_timeout; +static void __iomem *ralink_wdt_base; + +static inline void rt_wdt_w32(unsigned reg, u32 val) +{ + __raw_writel(val, ralink_wdt_base + reg); +} + +static inline u32 rt_wdt_r32(unsigned reg) +{ + return __raw_readl(ralink_wdt_base + reg); +} + +static inline void ralink_wdt_keepalive(void) +{ + rt_wdt_w32(TIMER_REG_TMR1LOAD, ralink_wdt_timeout * ralink_wdt_freq); +} + +static inline void ralink_wdt_enable(void) +{ + u32 t; + + ralink_wdt_keepalive(); + + t = rt_wdt_r32(TIMER_REG_TMR1CTL); + t |= TMR1CTL_ENABLE; + rt_wdt_w32(TIMER_REG_TMR1CTL, t); +} + +static inline void ralink_wdt_disable(void) +{ + u32 t; + + ralink_wdt_keepalive(); + + t = rt_wdt_r32(TIMER_REG_TMR1CTL); + t &= ~TMR1CTL_ENABLE; + rt_wdt_w32(TIMER_REG_TMR1CTL, t); +} + +static int ralink_wdt_set_timeout(int val) +{ + if (val < 1 || val > ralink_wdt_max_timeout) { + pr_warn(DRIVER_NAME + ": timeout value %d must be 0 < timeout <= %d, using %d\n", + val, ralink_wdt_max_timeout, ralink_wdt_timeout); + return -EINVAL; + } + + ralink_wdt_timeout = val; + ralink_wdt_keepalive(); + + return 0; +} + +static int ralink_wdt_open(struct inode *inode, struct file *file) +{ + u32 t; + + if (test_and_set_bit(WDT_FLAGS_BUSY, &ralink_wdt_flags)) + return -EBUSY; + + clear_bit(WDT_FLAGS_EXPECT_CLOSE, &ralink_wdt_flags); + + t = rt_wdt_r32(TIMER_REG_TMR1CTL); + t &= ~(TMR1CTL_MODE_MASK << TMR1CTL_MODE_SHIFT | + TMR1CTL_PRESCALE_MASK); + t |= (TMR1CTL_MODE_WDT << TMR1CTL_MODE_SHIFT | + TMR1CTL_PRESCALE_65536); + rt_wdt_w32(TIMER_REG_TMR1CTL, t); + + ralink_wdt_enable(); + + return nonseekable_open(inode, file); +} + +static int ralink_wdt_release(struct inode *inode, struct file *file) +{ + if (test_bit(WDT_FLAGS_EXPECT_CLOSE, &ralink_wdt_flags)) + ralink_wdt_disable(); + else { + pr_crit(DRIVER_NAME ": device closed unexpectedly, " + "watchdog timer will not stop!\n"); + ralink_wdt_keepalive(); + } + + clear_bit(WDT_FLAGS_BUSY, &ralink_wdt_flags); + clear_bit(WDT_FLAGS_EXPECT_CLOSE, &ralink_wdt_flags); + + return 0; +} + +static ssize_t rt_wdt_w32ite(struct file *file, const char *data, + size_t len, loff_t *ppos) +{ + if (len) { + if (!nowayout) { + size_t i; + + clear_bit(WDT_FLAGS_EXPECT_CLOSE, &ralink_wdt_flags); + + for (i = 0; i != len; i++) { + char c; + + if (get_user(c, data + i)) + return -EFAULT; + + if (c == 'V') + set_bit(WDT_FLAGS_EXPECT_CLOSE, + &ralink_wdt_flags); + } + } + + ralink_wdt_keepalive(); + } + + return len; +} + +static const struct watchdog_info ralink_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, + .firmware_version = 0, + .identity = "RALINK watchdog", +}; + +static long ralink_wdt_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = argp; + int err; + int t; + + switch (cmd) { + case WDIOC_GETSUPPORT: + err = copy_to_user(argp, &ralink_wdt_info, + sizeof(ralink_wdt_info)) ? -EFAULT : 0; + break; + + case WDIOC_GETSTATUS: + err = put_user(0, p); + break; + + case WDIOC_KEEPALIVE: + ralink_wdt_keepalive(); + err = 0; + break; + + case WDIOC_SETTIMEOUT: + err = get_user(t, p); + if (err) + break; + + err = ralink_wdt_set_timeout(t); + if (err) + break; + + /* fallthrough */ + case WDIOC_GETTIMEOUT: + err = put_user(ralink_wdt_timeout, p); + break; + + default: + err = -ENOTTY; + break; + } + + return err; +} + +static const struct file_operations ralink_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = rt_wdt_w32ite, + .unlocked_ioctl = ralink_wdt_ioctl, + .open = ralink_wdt_open, + .release = ralink_wdt_release, +}; + +static struct miscdevice ralink_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &ralink_wdt_fops, +}; + +static int ralink_wdt_probe(struct platform_device *pdev) +{ + struct resource *res; + int err; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "no memory resource found\n"); + return -EINVAL; + } + + ralink_wdt_base = ioremap(res->start, resource_size(res)); + if (!ralink_wdt_base) + return -ENOMEM; + + ralink_wdt_clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(ralink_wdt_clk)) { + err = PTR_ERR(ralink_wdt_clk); + goto err_unmap; + } + + err = clk_enable(ralink_wdt_clk); + if (err) + goto err_clk_put; + + ralink_wdt_freq = clk_get_rate(ralink_wdt_clk) / RALINK_WDT_PRESCALE; + if (!ralink_wdt_freq) { + err = -EINVAL; + goto err_clk_disable; + } + + ralink_wdt_max_timeout = (0xfffful / ralink_wdt_freq); + if (ralink_wdt_timeout < 1 || + ralink_wdt_timeout > ralink_wdt_max_timeout) { + ralink_wdt_timeout = ralink_wdt_max_timeout; + dev_info(&pdev->dev, + "timeout value must be 0 < timeout <= %d, using %d\n", + ralink_wdt_max_timeout, ralink_wdt_timeout); + } + + err = misc_register(&ralink_wdt_miscdev); + if (err) { + dev_err(&pdev->dev, + "unable to register misc device, err=%d\n", err); + goto err_clk_disable; + } + + return 0; + +err_clk_disable: + clk_disable(ralink_wdt_clk); +err_clk_put: + clk_put(ralink_wdt_clk); +err_unmap: + iounmap(ralink_wdt_base); + return err; +} + +static int ralink_wdt_remove(struct platform_device *pdev) +{ + misc_deregister(&ralink_wdt_miscdev); + clk_disable(ralink_wdt_clk); + clk_put(ralink_wdt_clk); + iounmap(ralink_wdt_base); + return 0; +} + +static void ralink_wdt_shutdown(struct platform_device *pdev) +{ + ralink_wdt_disable(); +} + +static const struct of_device_id ralink_wdt_match[] = { + { .compatible = "ralink,rt2880-wdt" }, + {}, +}; +MODULE_DEVICE_TABLE(of, ralink_wdt_match); + +static struct platform_driver ralink_wdt_driver = { + .probe = ralink_wdt_probe, + .remove = ralink_wdt_remove, + .shutdown = ralink_wdt_shutdown, + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + .of_match_table = ralink_wdt_match, + }, +}; + +module_platform_driver(ralink_wdt_driver); + +MODULE_DESCRIPTION("MediaTek/Ralink RT288X/RT305X hardware watchdog driver"); +MODULE_AUTHOR("Gabor Juhos