linux/drivers/watchdog/digicolor_wdt.c
Pratyush Anand 6551881c86 Watchdog: Fix parent of watchdog_devices
/sys/class/watchdog/watchdogn/device/modalias can help to identify the
driver/module for a given watchdog node. However, many wdt devices do not
set their parent and so, we do not see an entry for device in sysfs for
such devices.

This patch fixes parent of watchdog_device so that
/sys/class/watchdog/watchdogn/device is populated.

Exceptions: booke, diag288, octeon, softdog and w83627hf -- They do not
have any parent. Not sure, how we can identify driver for these devices.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-09-09 21:39:22 +02:00

207 lines
4.8 KiB
C

/*
* Watchdog driver for Conexant Digicolor
*
* Copyright (C) 2015 Paradox Innovation Ltd.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/types.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/watchdog.h>
#include <linux/reboot.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#define TIMER_A_CONTROL 0
#define TIMER_A_COUNT 4
#define TIMER_A_ENABLE_COUNT BIT(0)
#define TIMER_A_ENABLE_WATCHDOG BIT(1)
struct dc_wdt {
void __iomem *base;
struct clk *clk;
struct notifier_block restart_handler;
spinlock_t lock;
};
static unsigned timeout;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
static void dc_wdt_set(struct dc_wdt *wdt, u32 ticks)
{
unsigned long flags;
spin_lock_irqsave(&wdt->lock, flags);
writel_relaxed(0, wdt->base + TIMER_A_CONTROL);
writel_relaxed(ticks, wdt->base + TIMER_A_COUNT);
writel_relaxed(TIMER_A_ENABLE_COUNT | TIMER_A_ENABLE_WATCHDOG,
wdt->base + TIMER_A_CONTROL);
spin_unlock_irqrestore(&wdt->lock, flags);
}
static int dc_restart_handler(struct notifier_block *this, unsigned long mode,
void *cmd)
{
struct dc_wdt *wdt = container_of(this, struct dc_wdt, restart_handler);
dc_wdt_set(wdt, 1);
/* wait for reset to assert... */
mdelay(500);
return NOTIFY_DONE;
}
static int dc_wdt_start(struct watchdog_device *wdog)
{
struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
dc_wdt_set(wdt, wdog->timeout * clk_get_rate(wdt->clk));
return 0;
}
static int dc_wdt_stop(struct watchdog_device *wdog)
{
struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
writel_relaxed(0, wdt->base + TIMER_A_CONTROL);
return 0;
}
static int dc_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t)
{
struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
dc_wdt_set(wdt, t * clk_get_rate(wdt->clk));
wdog->timeout = t;
return 0;
}
static unsigned int dc_wdt_get_timeleft(struct watchdog_device *wdog)
{
struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
uint32_t count = readl_relaxed(wdt->base + TIMER_A_COUNT);
return count / clk_get_rate(wdt->clk);
}
static struct watchdog_ops dc_wdt_ops = {
.owner = THIS_MODULE,
.start = dc_wdt_start,
.stop = dc_wdt_stop,
.set_timeout = dc_wdt_set_timeout,
.get_timeleft = dc_wdt_get_timeleft,
};
static struct watchdog_info dc_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE
| WDIOF_KEEPALIVEPING,
.identity = "Conexant Digicolor Watchdog",
};
static struct watchdog_device dc_wdt_wdd = {
.info = &dc_wdt_info,
.ops = &dc_wdt_ops,
.min_timeout = 1,
};
static int dc_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct dc_wdt *wdt;
int ret;
wdt = devm_kzalloc(dev, sizeof(struct dc_wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
platform_set_drvdata(pdev, wdt);
wdt->base = of_iomap(np, 0);
if (!wdt->base) {
dev_err(dev, "Failed to remap watchdog regs");
return -ENODEV;
}
wdt->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(wdt->clk)) {
ret = PTR_ERR(wdt->clk);
goto err_iounmap;
}
dc_wdt_wdd.max_timeout = U32_MAX / clk_get_rate(wdt->clk);
dc_wdt_wdd.timeout = dc_wdt_wdd.max_timeout;
dc_wdt_wdd.parent = &pdev->dev;
spin_lock_init(&wdt->lock);
watchdog_set_drvdata(&dc_wdt_wdd, wdt);
watchdog_init_timeout(&dc_wdt_wdd, timeout, dev);
ret = watchdog_register_device(&dc_wdt_wdd);
if (ret) {
dev_err(dev, "Failed to register watchdog device");
goto err_iounmap;
}
wdt->restart_handler.notifier_call = dc_restart_handler;
wdt->restart_handler.priority = 128;
ret = register_restart_handler(&wdt->restart_handler);
if (ret)
dev_warn(&pdev->dev, "cannot register restart handler\n");
return 0;
err_iounmap:
iounmap(wdt->base);
return ret;
}
static int dc_wdt_remove(struct platform_device *pdev)
{
struct dc_wdt *wdt = platform_get_drvdata(pdev);
unregister_restart_handler(&wdt->restart_handler);
watchdog_unregister_device(&dc_wdt_wdd);
iounmap(wdt->base);
return 0;
}
static void dc_wdt_shutdown(struct platform_device *pdev)
{
dc_wdt_stop(&dc_wdt_wdd);
}
static const struct of_device_id dc_wdt_of_match[] = {
{ .compatible = "cnxt,cx92755-wdt", },
{},
};
MODULE_DEVICE_TABLE(of, dc_wdt_of_match);
static struct platform_driver dc_wdt_driver = {
.probe = dc_wdt_probe,
.remove = dc_wdt_remove,
.shutdown = dc_wdt_shutdown,
.driver = {
.name = "digicolor-wdt",
.of_match_table = dc_wdt_of_match,
},
};
module_platform_driver(dc_wdt_driver);
MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
MODULE_DESCRIPTION("Driver for Conexant Digicolor watchdog timer");
MODULE_LICENSE("GPL");