170 lines
4.0 KiB
C
170 lines
4.0 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* System monitoring driver for DA9055 PMICs.
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*
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* Copyright(c) 2012 Dialog Semiconductor Ltd.
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*
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* Author: David Dajun Chen <dchen@diasemi.com>
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*
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#include <linux/delay.h>
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#include <linux/mfd/da9055/core.h>
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#include <linux/mfd/da9055/reg.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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#define DA9055_DEF_TIMEOUT 4
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#define DA9055_TWDMIN 256
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struct da9055_wdt_data {
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struct watchdog_device wdt;
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struct da9055 *da9055;
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};
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static const struct {
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u8 reg_val;
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int user_time; /* In seconds */
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} da9055_wdt_maps[] = {
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{ 0, 0 },
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{ 1, 2 },
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{ 2, 4 },
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{ 3, 8 },
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{ 4, 16 },
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{ 5, 32 },
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{ 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */
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{ 6, 65 },
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{ 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */
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{ 7, 131 },
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};
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static int da9055_wdt_set_timeout(struct watchdog_device *wdt_dev,
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unsigned int timeout)
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{
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struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
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struct da9055 *da9055 = driver_data->da9055;
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int ret, i;
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for (i = 0; i < ARRAY_SIZE(da9055_wdt_maps); i++)
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if (da9055_wdt_maps[i].user_time == timeout)
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break;
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if (i == ARRAY_SIZE(da9055_wdt_maps))
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ret = -EINVAL;
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else
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ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
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DA9055_TWDSCALE_MASK,
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da9055_wdt_maps[i].reg_val <<
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DA9055_TWDSCALE_SHIFT);
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if (ret < 0) {
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dev_err(da9055->dev,
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"Failed to update timescale bit, %d\n", ret);
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return ret;
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}
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wdt_dev->timeout = timeout;
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return 0;
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}
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static int da9055_wdt_ping(struct watchdog_device *wdt_dev)
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{
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struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
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struct da9055 *da9055 = driver_data->da9055;
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/*
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* We have a minimum time for watchdog window called TWDMIN. A write
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* to the watchdog before this elapsed time will cause an error.
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*/
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mdelay(DA9055_TWDMIN);
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/* Reset the watchdog timer */
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return da9055_reg_update(da9055, DA9055_REG_CONTROL_E,
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DA9055_WATCHDOG_MASK, 1);
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}
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static int da9055_wdt_start(struct watchdog_device *wdt_dev)
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{
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return da9055_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
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}
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static int da9055_wdt_stop(struct watchdog_device *wdt_dev)
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{
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return da9055_wdt_set_timeout(wdt_dev, 0);
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}
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static const struct watchdog_info da9055_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
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.identity = "DA9055 Watchdog",
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};
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static const struct watchdog_ops da9055_wdt_ops = {
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.owner = THIS_MODULE,
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.start = da9055_wdt_start,
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.stop = da9055_wdt_stop,
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.ping = da9055_wdt_ping,
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.set_timeout = da9055_wdt_set_timeout,
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};
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static int da9055_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct da9055 *da9055 = dev_get_drvdata(dev->parent);
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struct da9055_wdt_data *driver_data;
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struct watchdog_device *da9055_wdt;
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int ret;
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driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL);
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if (!driver_data)
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return -ENOMEM;
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driver_data->da9055 = da9055;
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da9055_wdt = &driver_data->wdt;
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da9055_wdt->timeout = DA9055_DEF_TIMEOUT;
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da9055_wdt->info = &da9055_wdt_info;
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da9055_wdt->ops = &da9055_wdt_ops;
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da9055_wdt->parent = dev;
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watchdog_set_nowayout(da9055_wdt, nowayout);
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watchdog_set_drvdata(da9055_wdt, driver_data);
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ret = da9055_wdt_stop(da9055_wdt);
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if (ret < 0) {
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dev_err(dev, "Failed to stop watchdog, %d\n", ret);
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return ret;
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}
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ret = devm_watchdog_register_device(dev, &driver_data->wdt);
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if (ret != 0)
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dev_err(da9055->dev, "watchdog_register_device() failed: %d\n",
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ret);
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return ret;
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}
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static struct platform_driver da9055_wdt_driver = {
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.probe = da9055_wdt_probe,
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.driver = {
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.name = "da9055-watchdog",
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},
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};
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module_platform_driver(da9055_wdt_driver);
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MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
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MODULE_DESCRIPTION("DA9055 watchdog");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:da9055-watchdog");
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