Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 171 insertions, 0 deletions

diff --git a/drivers/extcon/extcon-gpio.c b/drivers/extcon/extcon-gpio.c
new file mode 100644
index 000000000..13ba3a6e8
--- /dev/null
+++ b/drivers/extcon/extcon-gpio.c
@@ -0,0 +1,171 @@
+/*
+ * extcon_gpio.c - Single-state GPIO extcon driver based on extcon class
+ *
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
+ * (originally switch class is supported)
+ *
+ * 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.
+ */
+
+#include <linux/extcon-provider.h>
+#include <linux/gpio/consumer.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+/**
+ * struct gpio_extcon_data - A simple GPIO-controlled extcon device state container.
+ * @edev:		Extcon device.
+ * @irq:		Interrupt line for the external connector.
+ * @work:		Work fired by the interrupt.
+ * @debounce_jiffies:	Number of jiffies to wait for the GPIO to stabilize, from the debounce
+ *			value.
+ * @gpiod:		GPIO descriptor for this external connector.
+ * @extcon_id:		The unique id of specific external connector.
+ * @debounce:		Debounce time for GPIO IRQ in ms.
+ * @irq_flags:		IRQ Flags (e.g., IRQF_TRIGGER_LOW).
+ * @check_on_resume:	Boolean describing whether to check the state of gpio
+ *			while resuming from sleep.
+ */
+struct gpio_extcon_data {
+	struct extcon_dev *edev;
+	int irq;
+	struct delayed_work work;
+	unsigned long debounce_jiffies;
+	struct gpio_desc *gpiod;
+	unsigned int extcon_id;
+	unsigned long debounce;
+	unsigned long irq_flags;
+	bool check_on_resume;
+};
+
+static void gpio_extcon_work(struct work_struct *work)
+{
+	int state;
+	struct gpio_extcon_data	*data =
+		container_of(to_delayed_work(work), struct gpio_extcon_data,
+			     work);
+
+	state = gpiod_get_value_cansleep(data->gpiod);
+	extcon_set_state_sync(data->edev, data->extcon_id, state);
+}
+
+static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
+{
+	struct gpio_extcon_data *data = dev_id;
+
+	queue_delayed_work(system_power_efficient_wq, &data->work,
+			      data->debounce_jiffies);
+	return IRQ_HANDLED;
+}
+
+static int gpio_extcon_probe(struct platform_device *pdev)
+{
+	struct gpio_extcon_data *data;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	data = devm_kzalloc(dev, sizeof(struct gpio_extcon_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	/*
+	 * FIXME: extcon_id represents the unique identifier of external
+	 * connectors such as EXTCON_USB, EXTCON_DISP_HDMI and so on. extcon_id
+	 * is necessary to register the extcon device. But, it's not yet
+	 * developed to get the extcon id from device-tree or others.
+	 * On later, it have to be solved.
+	 */
+	if (!data->irq_flags || data->extcon_id > EXTCON_NONE)
+		return -EINVAL;
+
+	data->gpiod = devm_gpiod_get(dev, "extcon", GPIOD_IN);
+	if (IS_ERR(data->gpiod))
+		return PTR_ERR(data->gpiod);
+	data->irq = gpiod_to_irq(data->gpiod);
+	if (data->irq <= 0)
+		return data->irq;
+
+	/* Allocate the memory of extcon devie and register extcon device */
+	data->edev = devm_extcon_dev_allocate(dev, &data->extcon_id);
+	if (IS_ERR(data->edev)) {
+		dev_err(dev, "failed to allocate extcon device\n");
+		return -ENOMEM;
+	}
+
+	ret = devm_extcon_dev_register(dev, data->edev);
+	if (ret < 0)
+		return ret;
+
+	INIT_DELAYED_WORK(&data->work, gpio_extcon_work);
+
+	/*
+	 * Request the interrupt of gpio to detect whether external connector
+	 * is attached or detached.
+	 */
+	ret = devm_request_any_context_irq(dev, data->irq,
+					gpio_irq_handler, data->irq_flags,
+					pdev->name, data);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, data);
+	/* Perform initial detection */
+	gpio_extcon_work(&data->work.work);
+
+	return 0;
+}
+
+static int gpio_extcon_remove(struct platform_device *pdev)
+{
+	struct gpio_extcon_data *data = platform_get_drvdata(pdev);
+
+	cancel_delayed_work_sync(&data->work);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int gpio_extcon_resume(struct device *dev)
+{
+	struct gpio_extcon_data *data;
+
+	data = dev_get_drvdata(dev);
+	if (data->check_on_resume)
+		queue_delayed_work(system_power_efficient_wq,
+			&data->work, data->debounce_jiffies);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
+
+static struct platform_driver gpio_extcon_driver = {
+	.probe		= gpio_extcon_probe,
+	.remove		= gpio_extcon_remove,
+	.driver		= {
+		.name	= "extcon-gpio",
+		.pm	= &gpio_extcon_pm_ops,
+	},
+};
+
+module_platform_driver(gpio_extcon_driver);
+
+MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
+MODULE_DESCRIPTION("GPIO extcon driver");
+MODULE_LICENSE("GPL");