mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
216 lines
5.2 KiB
C
216 lines
5.2 KiB
C
![]() |
/*
|
||
|
* Watchdog driver for TS-4800 based boards
|
||
|
*
|
||
|
* Copyright (c) 2015 - Savoir-faire Linux
|
||
|
*
|
||
|
* 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.
|
||
|
*/
|
||
|
|
||
|
#include <linux/kernel.h>
|
||
|
#include <linux/mfd/syscon.h>
|
||
|
#include <linux/module.h>
|
||
|
#include <linux/of.h>
|
||
|
#include <linux/platform_device.h>
|
||
|
#include <linux/regmap.h>
|
||
|
#include <linux/watchdog.h>
|
||
|
|
||
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
||
|
module_param(nowayout, bool, 0);
|
||
|
MODULE_PARM_DESC(nowayout,
|
||
|
"Watchdog cannot be stopped once started (default="
|
||
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
||
|
|
||
|
/* possible feed values */
|
||
|
#define TS4800_WDT_FEED_2S 0x1
|
||
|
#define TS4800_WDT_FEED_10S 0x2
|
||
|
#define TS4800_WDT_DISABLE 0x3
|
||
|
|
||
|
struct ts4800_wdt {
|
||
|
struct watchdog_device wdd;
|
||
|
struct regmap *regmap;
|
||
|
u32 feed_offset;
|
||
|
u32 feed_val;
|
||
|
};
|
||
|
|
||
|
/*
|
||
|
* TS-4800 supports the following timeout values:
|
||
|
*
|
||
|
* value desc
|
||
|
* ---------------------
|
||
|
* 0 feed for 338ms
|
||
|
* 1 feed for 2.706s
|
||
|
* 2 feed for 10.824s
|
||
|
* 3 disable watchdog
|
||
|
*
|
||
|
* Keep the regmap/timeout map ordered by timeout
|
||
|
*/
|
||
|
static const struct {
|
||
|
const int timeout;
|
||
|
const int regval;
|
||
|
} ts4800_wdt_map[] = {
|
||
|
{ 2, TS4800_WDT_FEED_2S },
|
||
|
{ 10, TS4800_WDT_FEED_10S },
|
||
|
};
|
||
|
|
||
|
#define MAX_TIMEOUT_INDEX (ARRAY_SIZE(ts4800_wdt_map) - 1)
|
||
|
|
||
|
static void ts4800_write_feed(struct ts4800_wdt *wdt, u32 val)
|
||
|
{
|
||
|
regmap_write(wdt->regmap, wdt->feed_offset, val);
|
||
|
}
|
||
|
|
||
|
static int ts4800_wdt_start(struct watchdog_device *wdd)
|
||
|
{
|
||
|
struct ts4800_wdt *wdt = watchdog_get_drvdata(wdd);
|
||
|
|
||
|
ts4800_write_feed(wdt, wdt->feed_val);
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int ts4800_wdt_stop(struct watchdog_device *wdd)
|
||
|
{
|
||
|
struct ts4800_wdt *wdt = watchdog_get_drvdata(wdd);
|
||
|
|
||
|
ts4800_write_feed(wdt, TS4800_WDT_DISABLE);
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int ts4800_wdt_set_timeout(struct watchdog_device *wdd,
|
||
|
unsigned int timeout)
|
||
|
{
|
||
|
struct ts4800_wdt *wdt = watchdog_get_drvdata(wdd);
|
||
|
int i;
|
||
|
|
||
|
for (i = 0; i < MAX_TIMEOUT_INDEX; i++) {
|
||
|
if (ts4800_wdt_map[i].timeout >= timeout)
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
wdd->timeout = ts4800_wdt_map[i].timeout;
|
||
|
wdt->feed_val = ts4800_wdt_map[i].regval;
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static const struct watchdog_ops ts4800_wdt_ops = {
|
||
|
.owner = THIS_MODULE,
|
||
|
.start = ts4800_wdt_start,
|
||
|
.stop = ts4800_wdt_stop,
|
||
|
.set_timeout = ts4800_wdt_set_timeout,
|
||
|
};
|
||
|
|
||
|
static const struct watchdog_info ts4800_wdt_info = {
|
||
|
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
|
||
|
.identity = "TS-4800 Watchdog",
|
||
|
};
|
||
|
|
||
|
static int ts4800_wdt_probe(struct platform_device *pdev)
|
||
|
{
|
||
|
struct device_node *np = pdev->dev.of_node;
|
||
|
struct device_node *syscon_np;
|
||
|
struct watchdog_device *wdd;
|
||
|
struct ts4800_wdt *wdt;
|
||
|
u32 reg;
|
||
|
int ret;
|
||
|
|
||
|
syscon_np = of_parse_phandle(np, "syscon", 0);
|
||
|
if (!syscon_np) {
|
||
|
dev_err(&pdev->dev, "no syscon property\n");
|
||
|
return -ENODEV;
|
||
|
}
|
||
|
|
||
|
ret = of_property_read_u32_index(np, "syscon", 1, ®);
|
||
|
if (ret < 0) {
|
||
|
dev_err(&pdev->dev, "no offset in syscon\n");
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
/* allocate memory for watchdog struct */
|
||
|
wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
|
||
|
if (!wdt)
|
||
|
return -ENOMEM;
|
||
|
|
||
|
/* set regmap and offset to know where to write */
|
||
|
wdt->feed_offset = reg;
|
||
|
wdt->regmap = syscon_node_to_regmap(syscon_np);
|
||
|
if (IS_ERR(wdt->regmap)) {
|
||
|
dev_err(&pdev->dev, "cannot get parent's regmap\n");
|
||
|
return PTR_ERR(wdt->regmap);
|
||
|
}
|
||
|
|
||
|
/* Initialize struct watchdog_device */
|
||
|
wdd = &wdt->wdd;
|
||
|
wdd->parent = &pdev->dev;
|
||
|
wdd->info = &ts4800_wdt_info;
|
||
|
wdd->ops = &ts4800_wdt_ops;
|
||
|
wdd->min_timeout = ts4800_wdt_map[0].timeout;
|
||
|
wdd->max_timeout = ts4800_wdt_map[MAX_TIMEOUT_INDEX].timeout;
|
||
|
|
||
|
watchdog_set_drvdata(wdd, wdt);
|
||
|
watchdog_set_nowayout(wdd, nowayout);
|
||
|
watchdog_init_timeout(wdd, 0, &pdev->dev);
|
||
|
|
||
|
/*
|
||
|
* As this watchdog supports only a few values, ts4800_wdt_set_timeout
|
||
|
* must be called to initialize timeout and feed_val with valid values.
|
||
|
* Default to maximum timeout if none, or an invalid one, is provided in
|
||
|
* device tree.
|
||
|
*/
|
||
|
if (!wdd->timeout)
|
||
|
wdd->timeout = wdd->max_timeout;
|
||
|
ts4800_wdt_set_timeout(wdd, wdd->timeout);
|
||
|
|
||
|
/*
|
||
|
* The feed register is write-only, so it is not possible to determine
|
||
|
* watchdog's state. Disable it to be in a known state.
|
||
|
*/
|
||
|
ts4800_wdt_stop(wdd);
|
||
|
|
||
|
ret = watchdog_register_device(wdd);
|
||
|
if (ret) {
|
||
|
dev_err(&pdev->dev,
|
||
|
"failed to register watchdog device\n");
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
platform_set_drvdata(pdev, wdt);
|
||
|
|
||
|
dev_info(&pdev->dev,
|
||
|
"initialized (timeout = %d sec, nowayout = %d)\n",
|
||
|
wdd->timeout, nowayout);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int ts4800_wdt_remove(struct platform_device *pdev)
|
||
|
{
|
||
|
struct ts4800_wdt *wdt = platform_get_drvdata(pdev);
|
||
|
|
||
|
watchdog_unregister_device(&wdt->wdd);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static const struct of_device_id ts4800_wdt_of_match[] = {
|
||
|
{ .compatible = "technologic,ts4800-wdt", },
|
||
|
{ },
|
||
|
};
|
||
|
MODULE_DEVICE_TABLE(of, ts4800_wdt_of_match);
|
||
|
|
||
|
static struct platform_driver ts4800_wdt_driver = {
|
||
|
.probe = ts4800_wdt_probe,
|
||
|
.remove = ts4800_wdt_remove,
|
||
|
.driver = {
|
||
|
.name = "ts4800_wdt",
|
||
|
.of_match_table = ts4800_wdt_of_match,
|
||
|
},
|
||
|
};
|
||
|
|
||
|
module_platform_driver(ts4800_wdt_driver);
|
||
|
|
||
|
MODULE_AUTHOR("Damien Riegel <damien.riegel@savoirfairelinux.com>");
|
||
|
MODULE_LICENSE("GPL v2");
|
||
|
MODULE_ALIAS("platform:ts4800_wdt");
|