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c8c844f28b
The core will print out details now. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
204 lines
5.0 KiB
C
204 lines
5.0 KiB
C
/*
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* Watchdog driver for TS-4800 based boards
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*
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* Copyright (c) 2015 - Savoir-faire Linux
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/kernel.h>
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#include <linux/mfd/syscon.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/watchdog.h>
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout,
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"Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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/* possible feed values */
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#define TS4800_WDT_FEED_2S 0x1
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#define TS4800_WDT_FEED_10S 0x2
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#define TS4800_WDT_DISABLE 0x3
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struct ts4800_wdt {
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struct watchdog_device wdd;
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struct regmap *regmap;
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u32 feed_offset;
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u32 feed_val;
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};
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/*
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* TS-4800 supports the following timeout values:
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*
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* value desc
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* ---------------------
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* 0 feed for 338ms
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* 1 feed for 2.706s
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* 2 feed for 10.824s
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* 3 disable watchdog
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*
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* Keep the regmap/timeout map ordered by timeout
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*/
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static const struct {
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const int timeout;
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const int regval;
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} ts4800_wdt_map[] = {
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{ 2, TS4800_WDT_FEED_2S },
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{ 10, TS4800_WDT_FEED_10S },
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};
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#define MAX_TIMEOUT_INDEX (ARRAY_SIZE(ts4800_wdt_map) - 1)
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static void ts4800_write_feed(struct ts4800_wdt *wdt, u32 val)
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{
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regmap_write(wdt->regmap, wdt->feed_offset, val);
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}
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static int ts4800_wdt_start(struct watchdog_device *wdd)
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{
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struct ts4800_wdt *wdt = watchdog_get_drvdata(wdd);
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ts4800_write_feed(wdt, wdt->feed_val);
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return 0;
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}
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static int ts4800_wdt_stop(struct watchdog_device *wdd)
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{
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struct ts4800_wdt *wdt = watchdog_get_drvdata(wdd);
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ts4800_write_feed(wdt, TS4800_WDT_DISABLE);
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return 0;
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}
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static int ts4800_wdt_set_timeout(struct watchdog_device *wdd,
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unsigned int timeout)
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{
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struct ts4800_wdt *wdt = watchdog_get_drvdata(wdd);
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int i;
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for (i = 0; i < MAX_TIMEOUT_INDEX; i++) {
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if (ts4800_wdt_map[i].timeout >= timeout)
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break;
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}
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wdd->timeout = ts4800_wdt_map[i].timeout;
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wdt->feed_val = ts4800_wdt_map[i].regval;
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return 0;
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}
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static const struct watchdog_ops ts4800_wdt_ops = {
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.owner = THIS_MODULE,
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.start = ts4800_wdt_start,
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.stop = ts4800_wdt_stop,
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.set_timeout = ts4800_wdt_set_timeout,
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};
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static const struct watchdog_info ts4800_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
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.identity = "TS-4800 Watchdog",
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};
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static int ts4800_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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struct device_node *syscon_np;
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struct watchdog_device *wdd;
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struct ts4800_wdt *wdt;
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u32 reg;
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int ret;
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syscon_np = of_parse_phandle(np, "syscon", 0);
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if (!syscon_np) {
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dev_err(dev, "no syscon property\n");
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return -ENODEV;
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}
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ret = of_property_read_u32_index(np, "syscon", 1, ®);
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if (ret < 0) {
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dev_err(dev, "no offset in syscon\n");
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return ret;
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}
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/* allocate memory for watchdog struct */
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wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
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if (!wdt)
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return -ENOMEM;
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/* set regmap and offset to know where to write */
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wdt->feed_offset = reg;
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wdt->regmap = syscon_node_to_regmap(syscon_np);
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of_node_put(syscon_np);
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if (IS_ERR(wdt->regmap)) {
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dev_err(dev, "cannot get parent's regmap\n");
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return PTR_ERR(wdt->regmap);
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}
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/* Initialize struct watchdog_device */
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wdd = &wdt->wdd;
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wdd->parent = dev;
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wdd->info = &ts4800_wdt_info;
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wdd->ops = &ts4800_wdt_ops;
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wdd->min_timeout = ts4800_wdt_map[0].timeout;
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wdd->max_timeout = ts4800_wdt_map[MAX_TIMEOUT_INDEX].timeout;
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watchdog_set_drvdata(wdd, wdt);
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watchdog_set_nowayout(wdd, nowayout);
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watchdog_init_timeout(wdd, 0, dev);
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/*
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* As this watchdog supports only a few values, ts4800_wdt_set_timeout
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* must be called to initialize timeout and feed_val with valid values.
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* Default to maximum timeout if none, or an invalid one, is provided in
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* device tree.
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*/
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if (!wdd->timeout)
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wdd->timeout = wdd->max_timeout;
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ts4800_wdt_set_timeout(wdd, wdd->timeout);
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/*
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* The feed register is write-only, so it is not possible to determine
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* watchdog's state. Disable it to be in a known state.
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*/
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ts4800_wdt_stop(wdd);
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ret = devm_watchdog_register_device(dev, wdd);
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if (ret)
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return ret;
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platform_set_drvdata(pdev, wdt);
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dev_info(dev, "initialized (timeout = %d sec, nowayout = %d)\n",
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wdd->timeout, nowayout);
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return 0;
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}
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static const struct of_device_id ts4800_wdt_of_match[] = {
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{ .compatible = "technologic,ts4800-wdt", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, ts4800_wdt_of_match);
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static struct platform_driver ts4800_wdt_driver = {
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.probe = ts4800_wdt_probe,
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.driver = {
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.name = "ts4800_wdt",
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.of_match_table = ts4800_wdt_of_match,
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},
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};
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module_platform_driver(ts4800_wdt_driver);
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MODULE_AUTHOR("Damien Riegel <damien.riegel@savoirfairelinux.com>");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:ts4800_wdt");
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