Hi Roger,

On 01/20/2015 02:52 AM, Roger Quadros wrote:

Need to rename from extcon-usb.txt to extcon-gpio-usb.txt.

I think you better use "linux,extcon-gpio-usb"
because the point of this driver use the gpio for usb cable.

+- id-gpio: gpio for USB ID pin. See gpio binding.
+
+Example:
+	extcon_usb1 {
+		compatible = "linux,extcon-usb";

ditto.

Need to re-order it alphabetically.

Remove un-necessary blank line.

+ * Author: Roger Quadros [off-list ref]
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.h>
+#include <linux/extcon/extcon-gpio.h>

Is it necessary? I think it is your mistake?

+#include <linux/gpio.h>

Don't need it because 'of_gpio.h' includes already 'gpio.h'.

+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#define USB_GPIO_DEBOUNCE_MS	20	/* ms */
+
+struct usb_extcon_info {
+	struct device *dev;
+	struct extcon_dev *edev;
+
+	struct gpio_desc *id_gpiod;
+	int id_irq;
+
+	unsigned long debounce_jiffies;
+	struct delayed_work wq_detcable;
+};
+
+/* List of detectable cables */
+enum {
+	EXTCON_CABLE_USB = 0,
+	EXTCON_CABLE_USB_HOST,
+
+	EXTCON_CABLE_END,
+};
+
+static const char *usb_extcon_cable[] = {
+	[EXTCON_CABLE_USB] = "USB",
+	[EXTCON_CABLE_USB_HOST] = "USB-Host",
+	NULL,
+};
+
+static void usb_extcon_detect_cable(struct work_struct *work)
+{
+	int id;
+	struct usb_extcon_info *info;
+	const char **cable_names;
+
+	info  = container_of(to_delayed_work(work), struct usb_extcon_info,
+			     wq_detcable);
+	cable_names = info->edev->supported_cable;

I think you can use 'usb_extcon_cable' instead of 'cable_names'.
So, you will remove 'cable_names' variable.

+
+	/* check ID and update cable state */
+	id = gpiod_get_value_cansleep(info->id_gpiod);
+
+	if (id) {
+		/*
+		 * ID = 1 means USB HOST cable detached.
+		 * As we don't have event for USB peripheral cable attached,
+		 * we simulate USB peripheral attach here.
+		 */
+		extcon_set_cable_state(info->edev,
+				       cable_names[EXTCON_CABLE_USB_HOST],
+				       false);
+		extcon_set_cable_state(info->edev,
+				       cable_names[EXTCON_CABLE_USB], true);
+	} else {
+		/*
+		 * ID = 0 means USB HOST cable attached.
+		 * As we don't have event for USB peripheral cable detached,
+		 * we simulate USB peripheral detach here.
+		 */
+		extcon_set_cable_state(info->edev,
+				       cable_names[EXTCON_CABLE_USB], false);
+		extcon_set_cable_state(info->edev,
+				       cable_names[EXTCON_CABLE_USB_HOST],
+				       true);
+	}
+}
+
+static irqreturn_t usb_irq_handler(int irq, void *dev_id)
+{
+	struct usb_extcon_info *info = dev_id;
+
+	/* debounce the GPIO via delayed work */

I think this comment is not necessary.

+	queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
+			   info->debounce_jiffies);
+	return IRQ_HANDLED;
+}
+
+static int usb_extcon_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct usb_extcon_info *info;
+	int ret;
+
+	if (!np)
+		return -EINVAL;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(struct usb_extcon_info),

sizeof(struct usb_extcon_info) -> sizeof(*info)

+			    GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->dev = dev;
+	info->id_gpiod = devm_gpiod_get(&pdev->dev, "id");
+	if (IS_ERR(info->id_gpiod)) {
+		dev_err(dev, "failed to get ID GPIO\n");
+		return PTR_ERR(info->id_gpiod);
+	}
+
+	ret = gpiod_set_debounce(info->id_gpiod,
+				 USB_GPIO_DEBOUNCE_MS * 1000);
+	if (ret < 0)
+		info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);
+
+	INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);
+
+	info->id_irq = gpiod_to_irq(info->id_gpiod);
+	if (info->id_irq < 0) {
+		dev_err(dev, "failed to get ID IRQ\n");
+		return info->id_irq;
+	}
+
+	ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
+					usb_irq_handler,
+					IRQF_SHARED | IRQF_ONESHOT,

I prefer to add IRQF_NO_SUSPEND flag because IRQF_NO_SUSPEND flag is necessary
for wake-up from freeze pm state.

+					pdev->name, info);
+	if (ret < 0) {
+		dev_err(dev, "failed to request handler for ID IRQ\n");
+		return ret;
+	}
+
+	info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
+	if (IS_ERR(info->edev)) {
+		dev_err(dev, "failed to allocate extcon device\n");
+		return -ENOMEM;
+	}
+
+	ret = devm_extcon_dev_register(dev, info->edev);
+	if (ret < 0) {
+		dev_err(dev, "failed to allocate extcon device\n");

Wrong error information, you have to change verb (allocate -> register)

+		return ret;
+	}
+
+	platform_set_drvdata(pdev, info);

Need blank line.

+	/* Perform initial detection */
+	usb_extcon_detect_cable(&info->wq_detcable.work);
+
+	return 0;
+}
+
+static int usb_extcon_remove(struct platform_device *pdev)
+{
+	struct usb_extcon_info *info = platform_get_drvdata(pdev);
+
+	cancel_delayed_work_sync(&info->wq_detcable);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int usb_extcon_suspend(struct device *dev)
+{
+	struct usb_extcon_info *info;
+
+	info = dev_get_drvdata(dev);

Simplify this code as following:
	struct usb_extcon_info *info = dev_get_drvdata(dev);

+
+	if (!IS_ERR(info->id_gpiod))

I think that it is sufficient cheking without IS_ERR macro as following:
	if (info->id_gpiod)

+		enable_irq_wake(info->id_irq);
+
+	return 0;
+}
+
+static int usb_extcon_resume(struct device *dev)
+{
+	struct usb_extcon_info *info;
+
+	info = dev_get_drvdata(dev);

ditto.

+
+	if (!IS_ERR(info->id_gpiod))

ditto.

+		disable_irq_wake(info->id_irq);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
+			 usb_extcon_suspend, usb_extcon_resume);
+
+static struct of_device_id usb_extcon_dt_match[] = {
+	{ .compatible = "linux,extcon-usb", },

Change compatible name from "linux,extcon-usb", to "linux,extcon-gpio-usb".

+	{ /* end */ }
+};
+
+static struct platform_driver usb_extcon_driver = {
+	.probe		= usb_extcon_probe,
+	.remove		= usb_extcon_remove,
+	.driver		= {
+		.name	= "extcon-usb",
+		.pm	= &usb_extcon_pm_ops,
+		.of_match_table = usb_extcon_dt_match,
+	},
+};
+
+module_platform_driver(usb_extcon_driver);
+
+MODULE_AUTHOR("Roger Quadros [off-list ref]");
+MODULE_DESCRIPTION("USB GPIO extcon driver");
+MODULE_LICENSE("GPL v2");

Thanks,
Chanwoo Cho

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html