![Alexandre Belloni](/assets/img/avatar_default.png)
Readout the enabled state so it is possible to get the pre-userspace handler working. Also, avoid disabling the watchdog to ensure it continues working and triggers if there is an issue later in the boot or if userspace fails to start. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Tested-by: Gregory CLEMENT <gregory.clement@bootlin.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
268 lines
7 KiB
C
268 lines
7 KiB
C
/*
|
|
* drivers/char/watchdog/pnx4008_wdt.c
|
|
*
|
|
* Watchdog driver for PNX4008 board
|
|
*
|
|
* Authors: Dmitry Chigirev <source@mvista.com>,
|
|
* Vitaly Wool <vitalywool@gmail.com>
|
|
* Based on sa1100 driver,
|
|
* Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
|
|
*
|
|
* 2005-2006 (c) MontaVista Software, Inc.
|
|
*
|
|
* (C) 2012 Wolfram Sang, Pengutronix
|
|
*
|
|
* This file is licensed under the terms of the GNU General Public License
|
|
* version 2. This program is licensed "as is" without any warranty of any
|
|
* kind, whether express or implied.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/io.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/err.h>
|
|
#include <linux/of.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/reboot.h>
|
|
#include <mach/hardware.h>
|
|
|
|
/* WatchDog Timer - Chapter 23 Page 207 */
|
|
|
|
#define DEFAULT_HEARTBEAT 19
|
|
#define MAX_HEARTBEAT 60
|
|
|
|
/* Watchdog timer register set definition */
|
|
#define WDTIM_INT(p) ((p) + 0x0)
|
|
#define WDTIM_CTRL(p) ((p) + 0x4)
|
|
#define WDTIM_COUNTER(p) ((p) + 0x8)
|
|
#define WDTIM_MCTRL(p) ((p) + 0xC)
|
|
#define WDTIM_MATCH0(p) ((p) + 0x10)
|
|
#define WDTIM_EMR(p) ((p) + 0x14)
|
|
#define WDTIM_PULSE(p) ((p) + 0x18)
|
|
#define WDTIM_RES(p) ((p) + 0x1C)
|
|
|
|
/* WDTIM_INT bit definitions */
|
|
#define MATCH_INT 1
|
|
|
|
/* WDTIM_CTRL bit definitions */
|
|
#define COUNT_ENAB 1
|
|
#define RESET_COUNT (1 << 1)
|
|
#define DEBUG_EN (1 << 2)
|
|
|
|
/* WDTIM_MCTRL bit definitions */
|
|
#define MR0_INT 1
|
|
#undef RESET_COUNT0
|
|
#define RESET_COUNT0 (1 << 2)
|
|
#define STOP_COUNT0 (1 << 2)
|
|
#define M_RES1 (1 << 3)
|
|
#define M_RES2 (1 << 4)
|
|
#define RESFRC1 (1 << 5)
|
|
#define RESFRC2 (1 << 6)
|
|
|
|
/* WDTIM_EMR bit definitions */
|
|
#define EXT_MATCH0 1
|
|
#define MATCH_OUTPUT_HIGH (2 << 4) /*a MATCH_CTRL setting */
|
|
|
|
/* WDTIM_RES bit definitions */
|
|
#define WDOG_RESET 1 /* read only */
|
|
|
|
#define WDOG_COUNTER_RATE 13000000 /*the counter clock is 13 MHz fixed */
|
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
static unsigned int heartbeat;
|
|
|
|
static DEFINE_SPINLOCK(io_lock);
|
|
static void __iomem *wdt_base;
|
|
static struct clk *wdt_clk;
|
|
|
|
static int pnx4008_wdt_start(struct watchdog_device *wdd)
|
|
{
|
|
spin_lock(&io_lock);
|
|
|
|
/* stop counter, initiate counter reset */
|
|
writel(RESET_COUNT, WDTIM_CTRL(wdt_base));
|
|
/*wait for reset to complete. 100% guarantee event */
|
|
while (readl(WDTIM_COUNTER(wdt_base)))
|
|
cpu_relax();
|
|
/* internal and external reset, stop after that */
|
|
writel(M_RES2 | STOP_COUNT0 | RESET_COUNT0, WDTIM_MCTRL(wdt_base));
|
|
/* configure match output */
|
|
writel(MATCH_OUTPUT_HIGH, WDTIM_EMR(wdt_base));
|
|
/* clear interrupt, just in case */
|
|
writel(MATCH_INT, WDTIM_INT(wdt_base));
|
|
/* the longest pulse period 65541/(13*10^6) seconds ~ 5 ms. */
|
|
writel(0xFFFF, WDTIM_PULSE(wdt_base));
|
|
writel(wdd->timeout * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
|
|
/*enable counter, stop when debugger active */
|
|
writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base));
|
|
|
|
spin_unlock(&io_lock);
|
|
return 0;
|
|
}
|
|
|
|
static int pnx4008_wdt_stop(struct watchdog_device *wdd)
|
|
{
|
|
spin_lock(&io_lock);
|
|
|
|
writel(0, WDTIM_CTRL(wdt_base)); /*stop counter */
|
|
|
|
spin_unlock(&io_lock);
|
|
return 0;
|
|
}
|
|
|
|
static int pnx4008_wdt_set_timeout(struct watchdog_device *wdd,
|
|
unsigned int new_timeout)
|
|
{
|
|
wdd->timeout = new_timeout;
|
|
return 0;
|
|
}
|
|
|
|
static int pnx4008_restart_handler(struct watchdog_device *wdd,
|
|
unsigned long mode, void *cmd)
|
|
{
|
|
const char *boot_cmd = cmd;
|
|
|
|
/*
|
|
* Verify if a "cmd" passed from the userspace program rebooting
|
|
* the system; if available, handle it.
|
|
* - For details, see the 'reboot' syscall in kernel/reboot.c
|
|
* - If the received "cmd" is not supported, use the default mode.
|
|
*/
|
|
if (boot_cmd) {
|
|
if (boot_cmd[0] == 'h')
|
|
mode = REBOOT_HARD;
|
|
else if (boot_cmd[0] == 's')
|
|
mode = REBOOT_SOFT;
|
|
}
|
|
|
|
if (mode == REBOOT_SOFT) {
|
|
/* Force match output active */
|
|
writel(EXT_MATCH0, WDTIM_EMR(wdt_base));
|
|
/* Internal reset on match output (RESOUT_N not asserted) */
|
|
writel(M_RES1, WDTIM_MCTRL(wdt_base));
|
|
} else {
|
|
/* Instant assert of RESETOUT_N with pulse length 1mS */
|
|
writel(13000, WDTIM_PULSE(wdt_base));
|
|
writel(M_RES2 | RESFRC1 | RESFRC2, WDTIM_MCTRL(wdt_base));
|
|
}
|
|
|
|
/* Wait for watchdog to reset system */
|
|
mdelay(1000);
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static const struct watchdog_info pnx4008_wdt_ident = {
|
|
.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
|
|
WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
|
|
.identity = "PNX4008 Watchdog",
|
|
};
|
|
|
|
static const struct watchdog_ops pnx4008_wdt_ops = {
|
|
.owner = THIS_MODULE,
|
|
.start = pnx4008_wdt_start,
|
|
.stop = pnx4008_wdt_stop,
|
|
.set_timeout = pnx4008_wdt_set_timeout,
|
|
.restart = pnx4008_restart_handler,
|
|
};
|
|
|
|
static struct watchdog_device pnx4008_wdd = {
|
|
.info = &pnx4008_wdt_ident,
|
|
.ops = &pnx4008_wdt_ops,
|
|
.timeout = DEFAULT_HEARTBEAT,
|
|
.min_timeout = 1,
|
|
.max_timeout = MAX_HEARTBEAT,
|
|
};
|
|
|
|
static void pnx4008_clk_disable_unprepare(void *data)
|
|
{
|
|
clk_disable_unprepare(data);
|
|
}
|
|
|
|
static int pnx4008_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
int ret = 0;
|
|
|
|
watchdog_init_timeout(&pnx4008_wdd, heartbeat, dev);
|
|
|
|
wdt_base = devm_platform_ioremap_resource(pdev, 0);
|
|
if (IS_ERR(wdt_base))
|
|
return PTR_ERR(wdt_base);
|
|
|
|
wdt_clk = devm_clk_get(dev, NULL);
|
|
if (IS_ERR(wdt_clk))
|
|
return PTR_ERR(wdt_clk);
|
|
|
|
ret = clk_prepare_enable(wdt_clk);
|
|
if (ret)
|
|
return ret;
|
|
ret = devm_add_action_or_reset(dev, pnx4008_clk_disable_unprepare,
|
|
wdt_clk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
pnx4008_wdd.bootstatus = (readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
|
|
WDIOF_CARDRESET : 0;
|
|
pnx4008_wdd.parent = dev;
|
|
watchdog_set_nowayout(&pnx4008_wdd, nowayout);
|
|
watchdog_set_restart_priority(&pnx4008_wdd, 128);
|
|
|
|
if (readl(WDTIM_CTRL(wdt_base)) & COUNT_ENAB)
|
|
set_bit(WDOG_HW_RUNNING, &pnx4008_wdd.status);
|
|
|
|
ret = devm_watchdog_register_device(dev, &pnx4008_wdd);
|
|
if (ret < 0) {
|
|
dev_err(dev, "cannot register watchdog device\n");
|
|
return ret;
|
|
}
|
|
|
|
dev_info(dev, "heartbeat %d sec\n", pnx4008_wdd.timeout);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id pnx4008_wdt_match[] = {
|
|
{ .compatible = "nxp,pnx4008-wdt" },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, pnx4008_wdt_match);
|
|
#endif
|
|
|
|
static struct platform_driver platform_wdt_driver = {
|
|
.driver = {
|
|
.name = "pnx4008-watchdog",
|
|
.of_match_table = of_match_ptr(pnx4008_wdt_match),
|
|
},
|
|
.probe = pnx4008_wdt_probe,
|
|
};
|
|
|
|
module_platform_driver(platform_wdt_driver);
|
|
|
|
MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
|
|
MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
|
|
MODULE_DESCRIPTION("PNX4008 Watchdog Driver");
|
|
|
|
module_param(heartbeat, uint, 0);
|
|
MODULE_PARM_DESC(heartbeat,
|
|
"Watchdog heartbeat period in seconds from 1 to "
|
|
__MODULE_STRING(MAX_HEARTBEAT) ", default "
|
|
__MODULE_STRING(DEFAULT_HEARTBEAT));
|
|
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Set to 1 to keep watchdog running after device release");
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:pnx4008-watchdog");
|