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linux/drivers/watchdog/da9062_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

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/*
* da9062_wdt.c - WDT device driver for DA9062
* Copyright (C) 2015 Dialog Semiconductor 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/mfd/da9062/registers.h>
#include <linux/mfd/da9062/core.h>
#include <linux/regmap.h>
#include <linux/of.h>
static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
#define DA9062_TWDSCALE_DISABLE 0
#define DA9062_TWDSCALE_MIN 1
#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
#define DA9062_RESET_PROTECTION_MS 300
struct da9062_watchdog {
struct da9062 *hw;
struct watchdog_device wdtdev;
unsigned long j_time_stamp;
};
static void da9062_set_window_start(struct da9062_watchdog *wdt)
{
wdt->j_time_stamp = jiffies;
}
static void da9062_apply_window_protection(struct da9062_watchdog *wdt)
{
unsigned long delay = msecs_to_jiffies(DA9062_RESET_PROTECTION_MS);
unsigned long timeout = wdt->j_time_stamp + delay;
unsigned long now = jiffies;
unsigned int diff_ms;
/* if time-limit has not elapsed then wait for remainder */
if (time_before(now, timeout)) {
diff_ms = jiffies_to_msecs(timeout-now);
dev_dbg(wdt->hw->dev,
"Kicked too quickly. Delaying %u msecs\n", diff_ms);
msleep(diff_ms);
}
}
static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
{
unsigned int i;
for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
if (wdt_timeout[i] >= secs)
return i;
}
return DA9062_TWDSCALE_MAX;
}
static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
{
int ret;
da9062_apply_window_protection(wdt);
ret = regmap_update_bits(wdt->hw->regmap,
DA9062AA_CONTROL_F,
DA9062AA_WATCHDOG_MASK,
DA9062AA_WATCHDOG_MASK);
da9062_set_window_start(wdt);
return ret;
}
static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
unsigned int regval)
{
struct da9062 *chip = wdt->hw;
int ret;
ret = da9062_reset_watchdog_timer(wdt);
if (ret)
return ret;
return regmap_update_bits(chip->regmap,
DA9062AA_CONTROL_D,
DA9062AA_TWDSCALE_MASK,
regval);
}
static int da9062_wdt_start(struct watchdog_device *wdd)
{
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
unsigned int selector;
int ret;
selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
ret = da9062_wdt_update_timeout_register(wdt, selector);
if (ret)
dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
ret);
return ret;
}
static int da9062_wdt_stop(struct watchdog_device *wdd)
{
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
int ret;
ret = da9062_reset_watchdog_timer(wdt);
if (ret) {
dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
ret);
return ret;
}
ret = regmap_update_bits(wdt->hw->regmap,
DA9062AA_CONTROL_D,
DA9062AA_TWDSCALE_MASK,
DA9062_TWDSCALE_DISABLE);
if (ret)
dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
ret);
return ret;
}
static int da9062_wdt_ping(struct watchdog_device *wdd)
{
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
int ret;
ret = da9062_reset_watchdog_timer(wdt);
if (ret)
dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
ret);
return ret;
}
static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
unsigned int selector;
int ret;
selector = da9062_wdt_timeout_to_sel(timeout);
ret = da9062_wdt_update_timeout_register(wdt, selector);
if (ret)
dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
ret);
else
wdd->timeout = wdt_timeout[selector];
return ret;
}
static const struct watchdog_info da9062_watchdog_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "DA9062 WDT",
};
static const struct watchdog_ops da9062_watchdog_ops = {
.owner = THIS_MODULE,
.start = da9062_wdt_start,
.stop = da9062_wdt_stop,
.ping = da9062_wdt_ping,
.set_timeout = da9062_wdt_set_timeout,
};
static int da9062_wdt_probe(struct platform_device *pdev)
{
int ret;
struct da9062 *chip;
struct da9062_watchdog *wdt;
chip = dev_get_drvdata(pdev->dev.parent);
if (!chip)
return -EINVAL;
wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdt->hw = chip;
wdt->wdtdev.info = &da9062_watchdog_info;
wdt->wdtdev.ops = &da9062_watchdog_ops;
wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
wdt->wdtdev.parent = &pdev->dev;
watchdog_set_drvdata(&wdt->wdtdev, wdt);
dev_set_drvdata(&pdev->dev, wdt);
ret = watchdog_register_device(&wdt->wdtdev);
if (ret < 0) {
dev_err(wdt->hw->dev,
"watchdog registration failed (%d)\n", ret);
return ret;
}
da9062_set_window_start(wdt);
ret = da9062_wdt_ping(&wdt->wdtdev);
if (ret < 0)
watchdog_unregister_device(&wdt->wdtdev);
return ret;
}
static int da9062_wdt_remove(struct platform_device *pdev)
{
struct da9062_watchdog *wdt = dev_get_drvdata(&pdev->dev);
watchdog_unregister_device(&wdt->wdtdev);
return 0;
}
static struct platform_driver da9062_wdt_driver = {
.probe = da9062_wdt_probe,
.remove = da9062_wdt_remove,
.driver = {
.name = "da9062-watchdog",
},
};
module_platform_driver(da9062_wdt_driver);
MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
MODULE_DESCRIPTION("WDT device driver for Dialog DA9062");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9062-watchdog");
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