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path: root/drivers/watchdog/da9052_wdt.c
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Diffstat (limited to 'drivers/watchdog/da9052_wdt.c')
-rw-r--r--drivers/watchdog/da9052_wdt.c251
1 files changed, 251 insertions, 0 deletions
diff --git a/drivers/watchdog/da9052_wdt.c b/drivers/watchdog/da9052_wdt.c
new file mode 100644
index 00000000000..3f75129eb0a
--- /dev/null
+++ b/drivers/watchdog/da9052_wdt.c
@@ -0,0 +1,251 @@
+/*
+ * System monitoring driver for DA9052 PMICs.
+ *
+ * Copyright(c) 2012 Dialog Semiconductor Ltd.
+ *
+ * Author: Anthony Olech <Anthony.Olech@diasemi.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/platform_device.h>
+#include <linux/time.h>
+#include <linux/watchdog.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/delay.h>
+
+#include <linux/mfd/da9052/reg.h>
+#include <linux/mfd/da9052/da9052.h>
+
+#define DA9052_DEF_TIMEOUT 4
+#define DA9052_TWDMIN 256
+
+struct da9052_wdt_data {
+ struct watchdog_device wdt;
+ struct da9052 *da9052;
+ struct kref kref;
+ unsigned long jpast;
+};
+
+static const struct {
+ u8 reg_val;
+ int time; /* Seconds */
+} da9052_wdt_maps[] = {
+ { 1, 2 },
+ { 2, 4 },
+ { 3, 8 },
+ { 4, 16 },
+ { 5, 32 },
+ { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */
+ { 6, 65 },
+ { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */
+ { 7, 131 },
+};
+
+
+static void da9052_wdt_release_resources(struct kref *r)
+{
+ struct da9052_wdt_data *driver_data =
+ container_of(r, struct da9052_wdt_data, kref);
+
+ kfree(driver_data);
+}
+
+static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,
+ unsigned int timeout)
+{
+ struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
+ struct da9052 *da9052 = driver_data->da9052;
+ int ret, i;
+
+ /*
+ * Disable the Watchdog timer before setting
+ * new time out.
+ */
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_TWDSCALE, 0);
+ if (ret < 0) {
+ dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n",
+ ret);
+ return ret;
+ }
+ if (timeout) {
+ /*
+ * To change the timeout, da9052 needs to
+ * be disabled for at least 150 us.
+ */
+ udelay(150);
+
+ /* Set the desired timeout */
+ for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++)
+ if (da9052_wdt_maps[i].time == timeout)
+ break;
+
+ if (i == ARRAY_SIZE(da9052_wdt_maps))
+ ret = -EINVAL;
+ else
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_TWDSCALE,
+ da9052_wdt_maps[i].reg_val);
+ if (ret < 0) {
+ dev_err(da9052->dev,
+ "Failed to update timescale bit, %d\n", ret);
+ return ret;
+ }
+
+ wdt_dev->timeout = timeout;
+ driver_data->jpast = jiffies;
+ }
+
+ return 0;
+}
+
+static void da9052_wdt_ref(struct watchdog_device *wdt_dev)
+{
+ struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
+
+ kref_get(&driver_data->kref);
+}
+
+static void da9052_wdt_unref(struct watchdog_device *wdt_dev)
+{
+ struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
+
+ kref_put(&driver_data->kref, da9052_wdt_release_resources);
+}
+
+static int da9052_wdt_start(struct watchdog_device *wdt_dev)
+{
+ return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
+}
+
+static int da9052_wdt_stop(struct watchdog_device *wdt_dev)
+{
+ return da9052_wdt_set_timeout(wdt_dev, 0);
+}
+
+static int da9052_wdt_ping(struct watchdog_device *wdt_dev)
+{
+ struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
+ struct da9052 *da9052 = driver_data->da9052;
+ unsigned long msec, jnow = jiffies;
+ int ret;
+
+ /*
+ * We have a minimum time for watchdog window called TWDMIN. A write
+ * to the watchdog before this elapsed time should cause an error.
+ */
+ msec = (jnow - driver_data->jpast) * 1000/HZ;
+ if (msec < DA9052_TWDMIN)
+ mdelay(msec);
+
+ /* Reset the watchdog timer */
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_WATCHDOG, 1 << 7);
+ if (ret < 0)
+ goto err_strobe;
+
+ /*
+ * FIXME: Reset the watchdog core, in general PMIC
+ * is supposed to do this
+ */
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_WATCHDOG, 0 << 7);
+err_strobe:
+ return ret;
+}
+
+static struct watchdog_info da9052_wdt_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+ .identity = "DA9052 Watchdog",
+};
+
+static const struct watchdog_ops da9052_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = da9052_wdt_start,
+ .stop = da9052_wdt_stop,
+ .ping = da9052_wdt_ping,
+ .set_timeout = da9052_wdt_set_timeout,
+ .ref = da9052_wdt_ref,
+ .unref = da9052_wdt_unref,
+};
+
+
+static int __devinit da9052_wdt_probe(struct platform_device *pdev)
+{
+ struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
+ struct da9052_wdt_data *driver_data;
+ struct watchdog_device *da9052_wdt;
+ int ret;
+
+ driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
+ GFP_KERNEL);
+ if (!driver_data) {
+ dev_err(da9052->dev, "Unable to alloacate watchdog device\n");
+ ret = -ENOMEM;
+ goto err;
+ }
+ driver_data->da9052 = da9052;
+
+ da9052_wdt = &driver_data->wdt;
+
+ da9052_wdt->timeout = DA9052_DEF_TIMEOUT;
+ da9052_wdt->info = &da9052_wdt_info;
+ da9052_wdt->ops = &da9052_wdt_ops;
+ watchdog_set_drvdata(da9052_wdt, driver_data);
+
+ kref_init(&driver_data->kref);
+
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_TWDSCALE, 0);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n",
+ ret);
+ goto err;
+ }
+
+ ret = watchdog_register_device(&driver_data->wdt);
+ if (ret != 0) {
+ dev_err(da9052->dev, "watchdog_register_device() failed: %d\n",
+ ret);
+ goto err;
+ }
+
+ dev_set_drvdata(&pdev->dev, driver_data);
+err:
+ return ret;
+}
+
+static int __devexit da9052_wdt_remove(struct platform_device *pdev)
+{
+ struct da9052_wdt_data *driver_data = dev_get_drvdata(&pdev->dev);
+
+ watchdog_unregister_device(&driver_data->wdt);
+ kref_put(&driver_data->kref, da9052_wdt_release_resources);
+
+ return 0;
+}
+
+static struct platform_driver da9052_wdt_driver = {
+ .probe = da9052_wdt_probe,
+ .remove = __devexit_p(da9052_wdt_remove),
+ .driver = {
+ .name = "da9052-watchdog",
+ },
+};
+
+module_platform_driver(da9052_wdt_driver);
+
+MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
+MODULE_DESCRIPTION("DA9052 SM Device Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9052-watchdog");
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-19 22:26:47 +0000