+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-// Copyright (C) 2018 ROHM Semiconductors
-// ROHM BD70528MWV watchdog driver
-
-#include <linux/bcd.h>
-#include <linux/kernel.h>
-#include <linux/mfd/rohm-bd70528.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-#include <linux/regmap.h>
-#include <linux/watchdog.h>
-
-/*
- * Max time we can set is 1 hour, 59 minutes and 59 seconds
- * and Minimum time is 1 second
- */
-#define WDT_MAX_MS ((2 * 60 * 60 - 1) * 1000)
-#define WDT_MIN_MS 1000
-#define DEFAULT_TIMEOUT 60
-
-#define WD_CTRL_MAGIC1 0x55
-#define WD_CTRL_MAGIC2 0xAA
-
-struct wdtbd70528 {
- struct device *dev;
- struct regmap *regmap;
- struct rohm_regmap_dev *mfd;
- struct watchdog_device wdt;
-};
-
-/**
- * bd70528_wdt_set - arm or disarm watchdog timer
- *
- * @data: device data for the PMIC instance we want to operate on
- * @enable: new state of WDT. zero to disable, non zero to enable
- * @old_state: previous state of WDT will be filled here
- *
- * Arm or disarm WDT on BD70528 PMIC. Expected to be called only by
- * BD70528 RTC and BD70528 WDT drivers. The rtc_timer_lock must be taken
- * by calling bd70528_wdt_lock before calling bd70528_wdt_set.
- */
-int bd70528_wdt_set(struct rohm_regmap_dev *data, int enable, int *old_state)
-{
- int ret, i;
- unsigned int tmp;
- struct bd70528_data *bd70528 = container_of(data, struct bd70528_data,
- chip);
- u8 wd_ctrl_arr[3] = { WD_CTRL_MAGIC1, WD_CTRL_MAGIC2, 0 };
- u8 *wd_ctrl = &wd_ctrl_arr[2];
-
- ret = regmap_read(bd70528->chip.regmap, BD70528_REG_WDT_CTRL, &tmp);
- if (ret)
- return ret;
-
- *wd_ctrl = (u8)tmp;
-
- if (old_state) {
- if (*wd_ctrl & BD70528_MASK_WDT_EN)
- *old_state |= BD70528_WDT_STATE_BIT;
- else
- *old_state &= ~BD70528_WDT_STATE_BIT;
- if ((!enable) == (!(*old_state & BD70528_WDT_STATE_BIT)))
- return 0;
- }
-
- if (enable) {
- if (*wd_ctrl & BD70528_MASK_WDT_EN)
- return 0;
- *wd_ctrl |= BD70528_MASK_WDT_EN;
- } else {
- if (*wd_ctrl & BD70528_MASK_WDT_EN)
- *wd_ctrl &= ~BD70528_MASK_WDT_EN;
- else
- return 0;
- }
-
- for (i = 0; i < 3; i++) {
- ret = regmap_write(bd70528->chip.regmap, BD70528_REG_WDT_CTRL,
- wd_ctrl_arr[i]);
- if (ret)
- return ret;
- }
-
- ret = regmap_read(bd70528->chip.regmap, BD70528_REG_WDT_CTRL, &tmp);
- if ((tmp & BD70528_MASK_WDT_EN) != (*wd_ctrl & BD70528_MASK_WDT_EN)) {
- dev_err(bd70528->chip.dev,
- "Watchdog ctrl mismatch (hw) 0x%x (set) 0x%x\n",
- tmp, *wd_ctrl);
- ret = -EIO;
- }
-
- return ret;
-}
-EXPORT_SYMBOL(bd70528_wdt_set);
-
-/**
- * bd70528_wdt_lock - take WDT lock
- *
- * @data: device data for the PMIC instance we want to operate on
- *
- * Lock WDT for arming/disarming in order to avoid race condition caused
- * by WDT state changes initiated by WDT and RTC drivers.
- */
-void bd70528_wdt_lock(struct rohm_regmap_dev *data)
-{
- struct bd70528_data *bd70528 = container_of(data, struct bd70528_data,
- chip);
-
- mutex_lock(&bd70528->rtc_timer_lock);
-}
-EXPORT_SYMBOL(bd70528_wdt_lock);
-
-/**
- * bd70528_wdt_unlock - unlock WDT lock
- *
- * @data: device data for the PMIC instance we want to operate on
- *
- * Unlock WDT lock which has previously been taken by call to
- * bd70528_wdt_lock.
- */
-void bd70528_wdt_unlock(struct rohm_regmap_dev *data)
-{
- struct bd70528_data *bd70528 = container_of(data, struct bd70528_data,
- chip);
-
- mutex_unlock(&bd70528->rtc_timer_lock);
-}
-EXPORT_SYMBOL(bd70528_wdt_unlock);
-
-static int bd70528_wdt_set_locked(struct wdtbd70528 *w, int enable)
-{
- return bd70528_wdt_set(w->mfd, enable, NULL);
-}
-
-static int bd70528_wdt_change(struct wdtbd70528 *w, int enable)
-{
- int ret;
-
- bd70528_wdt_lock(w->mfd);
- ret = bd70528_wdt_set_locked(w, enable);
- bd70528_wdt_unlock(w->mfd);
-
- return ret;
-}
-
-static int bd70528_wdt_start(struct watchdog_device *wdt)
-{
- struct wdtbd70528 *w = watchdog_get_drvdata(wdt);
-
- dev_dbg(w->dev, "WDT ping...\n");
- return bd70528_wdt_change(w, 1);
-}
-
-static int bd70528_wdt_stop(struct watchdog_device *wdt)
-{
- struct wdtbd70528 *w = watchdog_get_drvdata(wdt);
-
- dev_dbg(w->dev, "WDT stopping...\n");
- return bd70528_wdt_change(w, 0);
-}
-
-static int bd70528_wdt_set_timeout(struct watchdog_device *wdt,
- unsigned int timeout)
-{
- unsigned int hours;
- unsigned int minutes;
- unsigned int seconds;
- int ret;
- struct wdtbd70528 *w = watchdog_get_drvdata(wdt);
-
- seconds = timeout;
- hours = timeout / (60 * 60);
- /* Maximum timeout is 1h 59m 59s => hours is 1 or 0 */
- if (hours)
- seconds -= (60 * 60);
- minutes = seconds / 60;
- seconds = seconds % 60;
-
- bd70528_wdt_lock(w->mfd);
-
- ret = bd70528_wdt_set_locked(w, 0);
- if (ret)
- goto out_unlock;
-
- ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_HOUR,
- BD70528_MASK_WDT_HOUR, hours);
- if (ret) {
- dev_err(w->dev, "Failed to set WDT hours\n");
- goto out_en_unlock;
- }
- ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_MINUTE,
- BD70528_MASK_WDT_MINUTE, bin2bcd(minutes));
- if (ret) {
- dev_err(w->dev, "Failed to set WDT minutes\n");
- goto out_en_unlock;
- }
- ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_SEC,
- BD70528_MASK_WDT_SEC, bin2bcd(seconds));
- if (ret)
- dev_err(w->dev, "Failed to set WDT seconds\n");
- else
- dev_dbg(w->dev, "WDT tmo set to %u\n", timeout);
-
-out_en_unlock:
- ret = bd70528_wdt_set_locked(w, 1);
-out_unlock:
- bd70528_wdt_unlock(w->mfd);
-
- return ret;
-}
-
-static const struct watchdog_info bd70528_wdt_info = {
- .identity = "bd70528-wdt",
- .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
-};
-
-static const struct watchdog_ops bd70528_wdt_ops = {
- .start = bd70528_wdt_start,
- .stop = bd70528_wdt_stop,
- .set_timeout = bd70528_wdt_set_timeout,
-};
-
-static int bd70528_wdt_probe(struct platform_device *pdev)
-{
- struct rohm_regmap_dev *bd70528;
- struct wdtbd70528 *w;
- int ret;
- unsigned int reg;
-
- bd70528 = dev_get_drvdata(pdev->dev.parent);
- if (!bd70528) {
- dev_err(&pdev->dev, "No MFD driver data\n");
- return -EINVAL;
- }
- w = devm_kzalloc(&pdev->dev, sizeof(*w), GFP_KERNEL);
- if (!w)
- return -ENOMEM;
-
- w->regmap = bd70528->regmap;
- w->mfd = bd70528;
- w->dev = &pdev->dev;
-
- w->wdt.info = &bd70528_wdt_info;
- w->wdt.ops = &bd70528_wdt_ops;
- w->wdt.min_hw_heartbeat_ms = WDT_MIN_MS;
- w->wdt.max_hw_heartbeat_ms = WDT_MAX_MS;
- w->wdt.parent = pdev->dev.parent;
- w->wdt.timeout = DEFAULT_TIMEOUT;
- watchdog_set_drvdata(&w->wdt, w);
- watchdog_init_timeout(&w->wdt, 0, pdev->dev.parent);
-
- ret = bd70528_wdt_set_timeout(&w->wdt, w->wdt.timeout);
- if (ret) {
- dev_err(&pdev->dev, "Failed to set the watchdog timeout\n");
- return ret;
- }
-
- bd70528_wdt_lock(w->mfd);
- ret = regmap_read(w->regmap, BD70528_REG_WDT_CTRL, ®);
- bd70528_wdt_unlock(w->mfd);
-
- if (ret) {
- dev_err(&pdev->dev, "Failed to get the watchdog state\n");
- return ret;
- }
- if (reg & BD70528_MASK_WDT_EN) {
- dev_dbg(&pdev->dev, "watchdog was running during probe\n");
- set_bit(WDOG_HW_RUNNING, &w->wdt.status);
- }
-
- ret = devm_watchdog_register_device(&pdev->dev, &w->wdt);
- if (ret < 0)
- dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret);
-
- return ret;
-}
-
-static struct platform_driver bd70528_wdt = {
- .driver = {
- .name = "bd70528-wdt"
- },
- .probe = bd70528_wdt_probe,
-};
-
-module_platform_driver(bd70528_wdt);
-
-MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
-MODULE_DESCRIPTION("BD70528 watchdog driver");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:bd70528-wdt");
projects / platform / kernel / linux-rpi.git / commitdiff