cregit-Linux how code gets into the kernel

Release 4.14 drivers/watchdog/ts4800_wdt.c

Directory: drivers/watchdog
/*
 * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Damien Riegel27100.00%1100.00%
Total27100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Damien Riegel33100.00%1100.00%
Total33100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Damien Riegel31100.00%1100.00%
Total31100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Damien Riegel80100.00%1100.00%
Total80100.00%1100.00%

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, &reg); 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; }

Contributors

PersonTokensPropCommitsCommitProp
Damien Riegel345100.00%1100.00%
Total345100.00%1100.00%


static int ts4800_wdt_remove(struct platform_device *pdev) { struct ts4800_wdt *wdt = platform_get_drvdata(pdev); watchdog_unregister_device(&wdt->wdd); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Damien Riegel32100.00%1100.00%
Total32100.00%1100.00%

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");

Overall Contributors

PersonTokensPropCommitsCommitProp
Damien Riegel792100.00%1100.00%
Total792100.00%1100.00%
Directory: drivers/watchdog
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.