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

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);