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authorLinus Torvalds <torvalds@linux-foundation.org>2014-10-15 06:56:23 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-15 06:56:23 +0200
commit50fa86172bec2769979b5eb0cd1a244391ae4bb0 (patch)
tree5fd4949b031e1362af8b226d6372da2604de13ff /drivers/power/reset/gpio-restart.c
parent6b0490816671b2f4126a99998c9bf3c8c0472de2 (diff)
parent7881c64716f3a7d60b325ed0ad4d15f49b474a43 (diff)
Merge tag 'for-v3.18' of git://git.infradead.org/battery-2.6
Pull power supply and reset updates from Sebastian Reichel: - Initial support for the following chips * max77836 (charger) * max14577 (charger) * bq27742 (battery gauge) * ltc2952 (poweroff) * stih416 (restart) * syscon-reboot (restart) * gpio-restart (restart) - cleanup of power supply core - misc fixes in power supply and reset drivers * tag 'for-v3.18' of git://git.infradead.org/battery-2.6: (48 commits) power: ab8500_fg: Fix build warning Documentation: charger: max14577: Update the date of introducing ABI power: reset: corrections for simple syscon reboot driver Documentation: power: reset: Add documentation for generic SYSCON reboot driver power: reset: Add generic SYSCON register mapped reset bq27x00_battery: Fix flag reading for bq27742 power: reset: use restart_notifier mechanism for msm-poweroff power: Add simple gpio-restart driver power: reset: st: Provide DT bindings for ST's Power Reset driver power: reset: Add restart functionality for STiH41x platforms power: charger-manager: Fix NULL pointer exception with missing cm-fuel-gauge power: max14577: Fix circular config SYSFS dependency power: gpio-charger: do not use gpio value directly power: max8925: Use of_get_child_by_name power: max8925: Fix NULL ptr dereference on memory allocation failure bq27x00_battery: Add support to bq27742 Documentation: charger: max14577: Document exported sysfs entry devicetree: mfd: max14577: Add device tree bindings document power: max17040: Add ID for MAX77836 Fuel Gauge block charger: max14577: Configure battery-dependent settings from DTS and sysfs ... Conflicts: drivers/power/reset/Kconfig drivers/power/reset/Makefile
Diffstat (limited to 'drivers/power/reset/gpio-restart.c')
-rw-r--r--drivers/power/reset/gpio-restart.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/power/reset/gpio-restart.c b/drivers/power/reset/gpio-restart.c
new file mode 100644
index 000000000000..a76829b3f1cd
--- /dev/null
+++ b/drivers/power/reset/gpio-restart.c
@@ -0,0 +1,149 @@
+/*
+ * Toggles a GPIO pin to restart a device
+ *
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Based on the gpio-poweroff driver.
+ */
+#include <linux/reboot.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of_platform.h>
+#include <linux/module.h>
+
+struct gpio_restart {
+ struct gpio_desc *reset_gpio;
+ struct notifier_block restart_handler;
+ u32 active_delay_ms;
+ u32 inactive_delay_ms;
+ u32 wait_delay_ms;
+};
+
+static int gpio_restart_notify(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ struct gpio_restart *gpio_restart =
+ container_of(this, struct gpio_restart, restart_handler);
+
+ /* drive it active, also inactive->active edge */
+ gpiod_direction_output(gpio_restart->reset_gpio, 1);
+ mdelay(gpio_restart->active_delay_ms);
+
+ /* drive inactive, also active->inactive edge */
+ gpiod_set_value(gpio_restart->reset_gpio, 0);
+ mdelay(gpio_restart->inactive_delay_ms);
+
+ /* drive it active, also inactive->active edge */
+ gpiod_set_value(gpio_restart->reset_gpio, 1);
+
+ /* give it some time */
+ mdelay(gpio_restart->wait_delay_ms);
+
+ WARN_ON(1);
+
+ return NOTIFY_DONE;
+}
+
+static int gpio_restart_probe(struct platform_device *pdev)
+{
+ struct gpio_restart *gpio_restart;
+ bool open_source = false;
+ u32 property;
+ int ret;
+
+ gpio_restart = devm_kzalloc(&pdev->dev, sizeof(*gpio_restart),
+ GFP_KERNEL);
+ if (!gpio_restart)
+ return -ENOMEM;
+
+ open_source = of_property_read_bool(pdev->dev.of_node, "open-source");
+
+ gpio_restart->reset_gpio = devm_gpiod_get(&pdev->dev, NULL,
+ open_source ? GPIOD_IN : GPIOD_OUT_LOW);
+ if (IS_ERR(gpio_restart->reset_gpio)) {
+ dev_err(&pdev->dev, "Could net get reset GPIO\n");
+ return PTR_ERR(gpio_restart->reset_gpio);
+ }
+
+ gpio_restart->restart_handler.notifier_call = gpio_restart_notify;
+ gpio_restart->restart_handler.priority = 128;
+ gpio_restart->active_delay_ms = 100;
+ gpio_restart->inactive_delay_ms = 100;
+ gpio_restart->wait_delay_ms = 3000;
+
+ ret = of_property_read_u32(pdev->dev.of_node, "priority", &property);
+ if (!ret) {
+ if (property > 255)
+ dev_err(&pdev->dev, "Invalid priority property: %u\n",
+ property);
+ else
+ gpio_restart->restart_handler.priority = property;
+ }
+
+ of_property_read_u32(pdev->dev.of_node, "active-delay",
+ &gpio_restart->active_delay_ms);
+ of_property_read_u32(pdev->dev.of_node, "inactive-delay",
+ &gpio_restart->inactive_delay_ms);
+ of_property_read_u32(pdev->dev.of_node, "wait-delay",
+ &gpio_restart->wait_delay_ms);
+
+ platform_set_drvdata(pdev, gpio_restart);
+
+ ret = register_restart_handler(&gpio_restart->restart_handler);
+ if (ret) {
+ dev_err(&pdev->dev, "%s: cannot register restart handler, %d\n",
+ __func__, ret);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int gpio_restart_remove(struct platform_device *pdev)
+{
+ struct gpio_restart *gpio_restart = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = unregister_restart_handler(&gpio_restart->restart_handler);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "%s: cannot unregister restart handler, %d\n",
+ __func__, ret);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id of_gpio_restart_match[] = {
+ { .compatible = "gpio-restart", },
+ {},
+};
+
+static struct platform_driver gpio_restart_driver = {
+ .probe = gpio_restart_probe,
+ .remove = gpio_restart_remove,
+ .driver = {
+ .name = "restart-gpio",
+ .owner = THIS_MODULE,
+ .of_match_table = of_gpio_restart_match,
+ },
+};
+
+module_platform_driver(gpio_restart_driver);
+
+MODULE_AUTHOR("David Riley <davidriley@chromium.org>");
+MODULE_DESCRIPTION("GPIO restart driver");
+MODULE_LICENSE("GPL");