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Diffstat (limited to 'drivers/watchdog/da9062_wdt.c')
-rw-r--r--drivers/watchdog/da9062_wdt.c286
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c
new file mode 100644
index 000000000..f02cbd530
--- /dev/null
+++ b/drivers/watchdog/da9062_wdt.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Watchdog device driver for DA9062 and DA9061 PMICs
+ * Copyright (C) 2015 Dialog Semiconductor Ltd.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include <linux/mfd/da9062/registers.h>
+#include <linux/mfd/da9062/core.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+
+static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
+#define DA9062_TWDSCALE_DISABLE 0
+#define DA9062_TWDSCALE_MIN 1
+#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
+#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
+#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
+#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
+#define DA9062_RESET_PROTECTION_MS 300
+
+struct da9062_watchdog {
+ struct da9062 *hw;
+ struct watchdog_device wdtdev;
+ bool use_sw_pm;
+};
+
+static unsigned int da9062_wdt_read_timeout(struct da9062_watchdog *wdt)
+{
+ unsigned int val;
+
+ regmap_read(wdt->hw->regmap, DA9062AA_CONTROL_D, &val);
+
+ return wdt_timeout[val & DA9062AA_TWDSCALE_MASK];
+}
+
+static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
+{
+ unsigned int i;
+
+ for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
+ if (wdt_timeout[i] >= secs)
+ return i;
+ }
+
+ return DA9062_TWDSCALE_MAX;
+}
+
+static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
+{
+ return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
+ DA9062AA_WATCHDOG_MASK,
+ DA9062AA_WATCHDOG_MASK);
+}
+
+static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
+ unsigned int regval)
+{
+ struct da9062 *chip = wdt->hw;
+
+ regmap_update_bits(chip->regmap,
+ DA9062AA_CONTROL_D,
+ DA9062AA_TWDSCALE_MASK,
+ DA9062_TWDSCALE_DISABLE);
+
+ usleep_range(150, 300);
+
+ return regmap_update_bits(chip->regmap,
+ DA9062AA_CONTROL_D,
+ DA9062AA_TWDSCALE_MASK,
+ regval);
+}
+
+static int da9062_wdt_start(struct watchdog_device *wdd)
+{
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+ unsigned int selector;
+ int ret;
+
+ selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
+ ret = da9062_wdt_update_timeout_register(wdt, selector);
+ if (ret)
+ dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
+ ret);
+
+ return ret;
+}
+
+static int da9062_wdt_stop(struct watchdog_device *wdd)
+{
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+ int ret;
+
+ ret = regmap_update_bits(wdt->hw->regmap,
+ DA9062AA_CONTROL_D,
+ DA9062AA_TWDSCALE_MASK,
+ DA9062_TWDSCALE_DISABLE);
+ if (ret)
+ dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
+ ret);
+
+ return ret;
+}
+
+static int da9062_wdt_ping(struct watchdog_device *wdd)
+{
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+ int ret;
+
+ /*
+ * Prevent pings from occurring late in system poweroff/reboot sequence
+ * and possibly locking out restart handler from accessing i2c bus.
+ */
+ if (system_state > SYSTEM_RUNNING)
+ return 0;
+
+ ret = da9062_reset_watchdog_timer(wdt);
+ if (ret)
+ dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
+ ret);
+
+ return ret;
+}
+
+static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+ unsigned int selector;
+ int ret;
+
+ selector = da9062_wdt_timeout_to_sel(timeout);
+ ret = da9062_wdt_update_timeout_register(wdt, selector);
+ if (ret)
+ dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
+ ret);
+ else
+ wdd->timeout = wdt_timeout[selector];
+
+ return ret;
+}
+
+static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
+ void *data)
+{
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+ struct i2c_client *client = to_i2c_client(wdt->hw->dev);
+ int ret;
+
+ /* Don't use regmap because it is not atomic safe */
+ ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
+ DA9062AA_SHUTDOWN_MASK);
+ if (ret < 0)
+ dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
+ ret);
+
+ /* wait for reset to assert... */
+ mdelay(500);
+
+ return ret;
+}
+
+static const struct watchdog_info da9062_watchdog_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+ .identity = "DA9062 WDT",
+};
+
+static const struct watchdog_ops da9062_watchdog_ops = {
+ .owner = THIS_MODULE,
+ .start = da9062_wdt_start,
+ .stop = da9062_wdt_stop,
+ .ping = da9062_wdt_ping,
+ .set_timeout = da9062_wdt_set_timeout,
+ .restart = da9062_wdt_restart,
+};
+
+static const struct of_device_id da9062_compatible_id_table[] = {
+ { .compatible = "dlg,da9062-watchdog", },
+ { },
+};
+
+MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
+
+static int da9062_wdt_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ unsigned int timeout;
+ struct da9062 *chip;
+ struct da9062_watchdog *wdt;
+
+ chip = dev_get_drvdata(dev->parent);
+ if (!chip)
+ return -EINVAL;
+
+ wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ wdt->use_sw_pm = device_property_present(dev, "dlg,use-sw-pm");
+
+ wdt->hw = chip;
+
+ wdt->wdtdev.info = &da9062_watchdog_info;
+ wdt->wdtdev.ops = &da9062_watchdog_ops;
+ wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
+ wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
+ wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
+ wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
+ wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
+ wdt->wdtdev.parent = dev;
+
+ watchdog_set_restart_priority(&wdt->wdtdev, 128);
+
+ watchdog_set_drvdata(&wdt->wdtdev, wdt);
+ dev_set_drvdata(dev, &wdt->wdtdev);
+
+ timeout = da9062_wdt_read_timeout(wdt);
+ if (timeout)
+ wdt->wdtdev.timeout = timeout;
+
+ /* Set timeout from DT value if available */
+ watchdog_init_timeout(&wdt->wdtdev, 0, dev);
+
+ if (timeout) {
+ da9062_wdt_set_timeout(&wdt->wdtdev, wdt->wdtdev.timeout);
+ set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status);
+ }
+
+ return devm_watchdog_register_device(dev, &wdt->wdtdev);
+}
+
+static int __maybe_unused da9062_wdt_suspend(struct device *dev)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+
+ if (!wdt->use_sw_pm)
+ return 0;
+
+ if (watchdog_active(wdd))
+ return da9062_wdt_stop(wdd);
+
+ return 0;
+}
+
+static int __maybe_unused da9062_wdt_resume(struct device *dev)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+
+ if (!wdt->use_sw_pm)
+ return 0;
+
+ if (watchdog_active(wdd))
+ return da9062_wdt_start(wdd);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
+ da9062_wdt_suspend, da9062_wdt_resume);
+
+static struct platform_driver da9062_wdt_driver = {
+ .probe = da9062_wdt_probe,
+ .driver = {
+ .name = "da9062-watchdog",
+ .pm = &da9062_wdt_pm_ops,
+ .of_match_table = da9062_compatible_id_table,
+ },
+};
+module_platform_driver(da9062_wdt_driver);
+
+MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
+MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9062-watchdog");