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Commit 637b78eb authored by Tomoya MORINAGA's avatar Tomoya MORINAGA Committed by Felipe Balbi
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usb: gadget: pch_udc: Detecting VBUS through GPIO with interrupt 



Problem:
 pch_udc continues operation even if VBUS becomes Low.
 pch_udc performs D+ pulling up before VBUS becomes High.
 USB device should be controlled according to VBUS state.

Root cause:
 The current pch_udc is not always monitoring VBUS.

Solution:
 The change of VBUS is detected using an interrupt of GPIO.
 If VBUS became Low, pch_udc handles 'disconnect'.
 After VBUS became High, a pull improves D+, and pch_udc
 handles 'connect'.

[ balbi@ti.com : make it actually compile ]

Signed-off-by: default avatarTomoya MORINAGA <tomoya.rohm@gmail.com>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
parent dd63180b

drivers/usb/gadget/pch_udc.c

+83 −4
Original line number Diff line number Diff line
@@ -306,11 +306,15 @@ struct pch_udc_ep { 
 * struct pch_vbus_gpio_data - Structure holding GPIO informaton

 *					for detecting VBUS

 * @port:		gpio port number

 * @intr:		gpio interrupt number

 * @irq_work_fall	Structure for WorkQueue

 * @irq_work_rise	Structure for WorkQueue

 */

struct pch_vbus_gpio_data {

	int			port;

	int			intr;

	struct work_struct	irq_work_fall;

	struct work_struct	irq_work_rise;

};



/**
@@ -1296,8 +1300,10 @@ static void pch_vbus_gpio_work_fall(struct work_struct *irq_work) 
				dev->driver->disconnect(

					&dev->gadget);

			}

			if (dev->vbus_gpio.intr)

				pch_udc_init(dev);

			else

				pch_udc_reconnect(dev);

			dev_dbg(&dev->pdev->dev, "VBUS fell");

			return;

		}

		vbus_saved = vbus;
@@ -1305,6 +1311,57 @@ static void pch_vbus_gpio_work_fall(struct work_struct *irq_work) 
	}

}



/**

 * pch_vbus_gpio_work_rise() - This API checks VBUS is High.

 *                             If VBUS is High, connect is processed

 * @irq_work:	Structure for WorkQueue

 *

 */

static void pch_vbus_gpio_work_rise(struct work_struct *irq_work)

{

	struct pch_vbus_gpio_data *vbus_gpio = container_of(irq_work,

		struct pch_vbus_gpio_data, irq_work_rise);

	struct pch_udc_dev *dev =

		container_of(vbus_gpio, struct pch_udc_dev, vbus_gpio);

	int vbus;



	if (!dev->vbus_gpio.port)

		return;



	mdelay(PCH_VBUS_INTERVAL);

	vbus = pch_vbus_gpio_get_value(dev);



	if (vbus == 1) {

		dev_dbg(&dev->pdev->dev, "VBUS rose");

		pch_udc_reconnect(dev);

		return;

	}

}



/**

 * pch_vbus_gpio_irq() - IRQ handler for GPIO intrerrupt for changing VBUS

 * @irq:	Interrupt request number

 * @dev:	Reference to the device structure

 *

 * Return codes:

 *	0: Success

 *	-EINVAL: GPIO port is invalid or can't be initialized.

 */

static irqreturn_t pch_vbus_gpio_irq(int irq, void *data)

{

	struct pch_udc_dev *dev = (struct pch_udc_dev *)data;



	if (!dev->vbus_gpio.port || !dev->vbus_gpio.intr)

		return IRQ_NONE;



	if (pch_vbus_gpio_get_value(dev))

		schedule_work(&dev->vbus_gpio.irq_work_rise);

	else

		schedule_work(&dev->vbus_gpio.irq_work_fall);



	return IRQ_HANDLED;

}



/**

 * pch_vbus_gpio_init() - This API initializes GPIO port detecting VBUS.

 * @dev:	Reference to the driver structure
@@ -1317,8 +1374,10 @@ static void pch_vbus_gpio_work_fall(struct work_struct *irq_work) 
static int pch_vbus_gpio_init(struct pch_udc_dev *dev, int vbus_gpio_port)

{

	int err;

	int irq_num = 0;



	dev->vbus_gpio.port = 0;

	dev->vbus_gpio.intr = 0;



	if (vbus_gpio_port <= -1)

		return -EINVAL;
@@ -1341,6 +1400,21 @@ static int pch_vbus_gpio_init(struct pch_udc_dev *dev, int vbus_gpio_port) 
	gpio_direction_input(vbus_gpio_port);

	INIT_WORK(&dev->vbus_gpio.irq_work_fall, pch_vbus_gpio_work_fall);



	irq_num = gpio_to_irq(vbus_gpio_port);

	if (irq_num > 0) {

		irq_set_irq_type(irq_num, IRQ_TYPE_EDGE_BOTH);

		err = request_irq(irq_num, pch_vbus_gpio_irq, 0,

			"vbus_detect", dev);

		if (!err) {

			dev->vbus_gpio.intr = irq_num;

			INIT_WORK(&dev->vbus_gpio.irq_work_rise,

				pch_vbus_gpio_work_rise);

		} else {

			pr_err("%s: can't request irq %d, err: %d\n",

				__func__, irq_num, err);

		}

	}



	return 0;

}
@@ -1350,6 +1424,9 @@ static int pch_vbus_gpio_init(struct pch_udc_dev *dev, int vbus_gpio_port) 
 */

static void pch_vbus_gpio_free(struct pch_udc_dev *dev)

{

	if (dev->vbus_gpio.intr)

		free_irq(dev->vbus_gpio.intr, dev);



	if (dev->vbus_gpio.port)

		gpio_free(dev->vbus_gpio.port);

}
@@ -2676,7 +2753,8 @@ static void pch_udc_dev_isr(struct pch_udc_dev *dev, u32 dev_intr) 
			}

			pch_udc_reconnect(dev);

		} else if ((dev->vbus_session == 0)

			&& (vbus == 1))

			&& (vbus == 1)

			&& !dev->vbus_gpio.intr)

			schedule_work(&dev->vbus_gpio.irq_work_fall);



		dev_dbg(&dev->pdev->dev, "USB_SUSPEND\n");
@@ -2941,6 +3019,7 @@ static int pch_udc_start(struct usb_gadget_driver *driver, 
	pch_udc_setup_ep0(dev);



	/* clear SD */

	if ((pch_vbus_gpio_get_value(dev) != 0) || !dev->vbus_gpio.intr)

		pch_udc_clear_disconnect(dev);



	dev->connected = 1;