openwrtv4/target/linux/ramips/patches-3.8/0137-watchdog-adds-ralink-wdt.patch

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From 14c1b064274d28cf88113a685c58374a515f3018 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
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 <blogic@openwrt.org>
---
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 <juhosg@openwrt.org>
+ *
+ * This driver was based on: drivers/watchdog/ixp4xx_wdt.c
+ * Author: Deepak Saxena <dsaxena@plexity.net>
+ * Copyright 2004 (c) MontaVista, Software, Inc.
+ *
+ * which again was based on sa1100 driver,
+ * Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
+ *
+ * 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 <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+#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 <juhosg@openwrt.org");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);