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355 lines
8.3 KiB
355 lines
8.3 KiB
/*
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* drivers/char/watchdog/pnx4008_wdt.c
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*
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* Watchdog driver for PNX4008 board
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*
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* Authors: Dmitry Chigirev <source@mvista.com>,
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* Vitaly Wool <vitalywool@gmail.com>
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* Based on sa1100 driver,
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* Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
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*
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* 2005-2006 (c) MontaVista Software, Inc. This file is licensed under
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* the terms of the GNU General Public License version 2. This program
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* is licensed "as is" without any warranty of any kind, whether express
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* or implied.
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/init.h>
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#include <linux/bitops.h>
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#include <linux/ioport.h>
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/clk.h>
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#include <linux/spinlock.h>
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#include <linux/uaccess.h>
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#include <linux/io.h>
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#include <mach/hardware.h>
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#define MODULE_NAME "PNX4008-WDT: "
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/* WatchDog Timer - Chapter 23 Page 207 */
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#define DEFAULT_HEARTBEAT 19
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#define MAX_HEARTBEAT 60
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/* Watchdog timer register set definition */
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#define WDTIM_INT(p) ((p) + 0x0)
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#define WDTIM_CTRL(p) ((p) + 0x4)
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#define WDTIM_COUNTER(p) ((p) + 0x8)
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#define WDTIM_MCTRL(p) ((p) + 0xC)
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#define WDTIM_MATCH0(p) ((p) + 0x10)
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#define WDTIM_EMR(p) ((p) + 0x14)
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#define WDTIM_PULSE(p) ((p) + 0x18)
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#define WDTIM_RES(p) ((p) + 0x1C)
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/* WDTIM_INT bit definitions */
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#define MATCH_INT 1
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/* WDTIM_CTRL bit definitions */
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#define COUNT_ENAB 1
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#define RESET_COUNT (1 << 1)
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#define DEBUG_EN (1 << 2)
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/* WDTIM_MCTRL bit definitions */
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#define MR0_INT 1
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#undef RESET_COUNT0
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#define RESET_COUNT0 (1 << 2)
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#define STOP_COUNT0 (1 << 2)
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#define M_RES1 (1 << 3)
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#define M_RES2 (1 << 4)
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#define RESFRC1 (1 << 5)
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#define RESFRC2 (1 << 6)
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/* WDTIM_EMR bit definitions */
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#define EXT_MATCH0 1
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#define MATCH_OUTPUT_HIGH (2 << 4) /*a MATCH_CTRL setting */
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/* WDTIM_RES bit definitions */
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#define WDOG_RESET 1 /* read only */
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#define WDOG_COUNTER_RATE 13000000 /*the counter clock is 13 MHz fixed */
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static int nowayout = WATCHDOG_NOWAYOUT;
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static int heartbeat = DEFAULT_HEARTBEAT;
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static DEFINE_SPINLOCK(io_lock);
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static unsigned long wdt_status;
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#define WDT_IN_USE 0
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#define WDT_OK_TO_CLOSE 1
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#define WDT_REGION_INITED 2
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#define WDT_DEVICE_INITED 3
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static unsigned long boot_status;
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static struct resource *wdt_mem;
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static void __iomem *wdt_base;
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struct clk *wdt_clk;
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static void wdt_enable(void)
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{
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spin_lock(&io_lock);
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if (wdt_clk)
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clk_set_rate(wdt_clk, 1);
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/* stop counter, initiate counter reset */
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__raw_writel(RESET_COUNT, WDTIM_CTRL(wdt_base));
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/*wait for reset to complete. 100% guarantee event */
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while (__raw_readl(WDTIM_COUNTER(wdt_base)))
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cpu_relax();
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/* internal and external reset, stop after that */
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__raw_writel(M_RES2 | STOP_COUNT0 | RESET_COUNT0,
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WDTIM_MCTRL(wdt_base));
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/* configure match output */
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__raw_writel(MATCH_OUTPUT_HIGH, WDTIM_EMR(wdt_base));
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/* clear interrupt, just in case */
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__raw_writel(MATCH_INT, WDTIM_INT(wdt_base));
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/* the longest pulse period 65541/(13*10^6) seconds ~ 5 ms. */
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__raw_writel(0xFFFF, WDTIM_PULSE(wdt_base));
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__raw_writel(heartbeat * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
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/*enable counter, stop when debugger active */
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__raw_writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base));
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spin_unlock(&io_lock);
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}
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static void wdt_disable(void)
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{
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spin_lock(&io_lock);
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__raw_writel(0, WDTIM_CTRL(wdt_base)); /*stop counter */
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if (wdt_clk)
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clk_set_rate(wdt_clk, 0);
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spin_unlock(&io_lock);
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}
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static int pnx4008_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(WDT_IN_USE, &wdt_status))
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return -EBUSY;
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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wdt_enable();
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return nonseekable_open(inode, file);
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}
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static ssize_t pnx4008_wdt_write(struct file *file, const char *data,
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size_t len, loff_t *ppos)
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{
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if (len) {
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if (!nowayout) {
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size_t i;
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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for (i = 0; i != len; i++) {
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char c;
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if (get_user(c, data + i))
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return -EFAULT;
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if (c == 'V')
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set_bit(WDT_OK_TO_CLOSE, &wdt_status);
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}
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}
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wdt_enable();
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}
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return len;
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}
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static const struct watchdog_info ident = {
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.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
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WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
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.identity = "PNX4008 Watchdog",
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};
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static long pnx4008_wdt_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret = -ENOTTY;
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int time;
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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ret = copy_to_user((struct watchdog_info *)arg, &ident,
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sizeof(ident)) ? -EFAULT : 0;
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break;
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case WDIOC_GETSTATUS:
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ret = put_user(0, (int *)arg);
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break;
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case WDIOC_GETBOOTSTATUS:
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ret = put_user(boot_status, (int *)arg);
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break;
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case WDIOC_KEEPALIVE:
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wdt_enable();
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ret = 0;
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break;
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case WDIOC_SETTIMEOUT:
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ret = get_user(time, (int *)arg);
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if (ret)
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break;
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if (time <= 0 || time > MAX_HEARTBEAT) {
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ret = -EINVAL;
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break;
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}
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heartbeat = time;
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wdt_enable();
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/* Fall through */
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case WDIOC_GETTIMEOUT:
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ret = put_user(heartbeat, (int *)arg);
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break;
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}
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return ret;
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}
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static int pnx4008_wdt_release(struct inode *inode, struct file *file)
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{
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if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status))
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printk(KERN_WARNING "WATCHDOG: Device closed unexpectdly\n");
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wdt_disable();
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clear_bit(WDT_IN_USE, &wdt_status);
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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return 0;
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}
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static const struct file_operations pnx4008_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = pnx4008_wdt_write,
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.unlocked_ioctl = pnx4008_wdt_ioctl,
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.open = pnx4008_wdt_open,
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.release = pnx4008_wdt_release,
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};
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static struct miscdevice pnx4008_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &pnx4008_wdt_fops,
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};
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static int __devinit pnx4008_wdt_probe(struct platform_device *pdev)
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{
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int ret = 0, size;
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struct resource *res;
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if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
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heartbeat = DEFAULT_HEARTBEAT;
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printk(KERN_INFO MODULE_NAME
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"PNX4008 Watchdog Timer: heartbeat %d sec\n", heartbeat);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (res == NULL) {
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printk(KERN_INFO MODULE_NAME
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"failed to get memory region resouce\n");
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return -ENOENT;
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}
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size = res->end - res->start + 1;
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wdt_mem = request_mem_region(res->start, size, pdev->name);
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if (wdt_mem == NULL) {
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printk(KERN_INFO MODULE_NAME "failed to get memory region\n");
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return -ENOENT;
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}
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wdt_base = (void __iomem *)IO_ADDRESS(res->start);
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wdt_clk = clk_get(&pdev->dev, "wdt_ck");
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if (IS_ERR(wdt_clk)) {
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ret = PTR_ERR(wdt_clk);
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release_resource(wdt_mem);
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kfree(wdt_mem);
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goto out;
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} else
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clk_set_rate(wdt_clk, 1);
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ret = misc_register(&pnx4008_wdt_miscdev);
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if (ret < 0) {
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printk(KERN_ERR MODULE_NAME "cannot register misc device\n");
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release_resource(wdt_mem);
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kfree(wdt_mem);
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clk_set_rate(wdt_clk, 0);
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} else {
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boot_status = (__raw_readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
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WDIOF_CARDRESET : 0;
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wdt_disable(); /*disable for now */
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set_bit(WDT_DEVICE_INITED, &wdt_status);
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}
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out:
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return ret;
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}
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static int __devexit pnx4008_wdt_remove(struct platform_device *pdev)
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{
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misc_deregister(&pnx4008_wdt_miscdev);
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if (wdt_clk) {
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clk_set_rate(wdt_clk, 0);
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clk_put(wdt_clk);
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wdt_clk = NULL;
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}
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if (wdt_mem) {
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release_resource(wdt_mem);
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kfree(wdt_mem);
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wdt_mem = NULL;
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}
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return 0;
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}
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static struct platform_driver platform_wdt_driver = {
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.driver = {
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.name = "pnx4008-watchdog",
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.owner = THIS_MODULE,
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},
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.probe = pnx4008_wdt_probe,
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.remove = __devexit_p(pnx4008_wdt_remove),
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};
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static int __init pnx4008_wdt_init(void)
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{
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return platform_driver_register(&platform_wdt_driver);
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}
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static void __exit pnx4008_wdt_exit(void)
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{
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platform_driver_unregister(&platform_wdt_driver);
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}
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module_init(pnx4008_wdt_init);
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module_exit(pnx4008_wdt_exit);
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MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
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MODULE_DESCRIPTION("PNX4008 Watchdog Driver");
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module_param(heartbeat, int, 0);
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MODULE_PARM_DESC(heartbeat,
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"Watchdog heartbeat period in seconds from 1 to "
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__MODULE_STRING(MAX_HEARTBEAT) ", default "
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__MODULE_STRING(DEFAULT_HEARTBEAT));
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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout,
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"Set to 1 to keep watchdog running after device release");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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MODULE_ALIAS("platform:pnx4008-watchdog");
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