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Commit dd63180b authored by Tomoya MORINAGA's avatar Tomoya MORINAGA Committed by Felipe Balbi
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usb: gadget: pch_udc: Detecting VBUS through GPIO 



Problem:
 In USB Suspend, pch_udc handles 'disconnect'.

Root cause:
 The current pch_udc is not monitoring VBUS.
 When USB cable is disconnected, USB Device Controller generates
 an interrupt of USB Suspend.
 pch_udc cannot distinguish it is USB Suspend or disconnect.
 Therefore, pch_udc handles 'disconnect' after an interrupt of
 USB Suspend happend.

Solution:
 VBUS is detected through GPIO.
 After an interrupt produced USB Suspend, if VBUS is Low,
 pch_udc handles 'disconnect'.
 If VBUS is High, pch_udc handles 'suspend'.

Signed-off-by: default avatarTomoya MORINAGA <tomoya.rohm@gmail.com>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
parent 20edfbb6

drivers/usb/gadget/pch_udc.c

+142 −3
Original line number Diff line number Diff line
@@ -15,6 +15,13 @@ 
#include <linux/interrupt.h>

#include <linux/usb/ch9.h>

#include <linux/usb/gadget.h>

#include <linux/gpio.h>



/* GPIO port for VBUS detecting */

static int vbus_gpio_port = -1;		/* GPIO port number (-1:Not used) */



#define PCH_VBUS_PERIOD		3000	/* VBUS polling period (msec) */

#define PCH_VBUS_INTERVAL	10	/* VBUS polling interval (msec) */



/* Address offset of Registers */

#define UDC_EP_REG_SHIFT	0x20	/* Offset to next EP */
@@ -295,6 +302,17 @@ struct pch_udc_ep { 
	unsigned long			epsts;

};



/**

 * struct pch_vbus_gpio_data - Structure holding GPIO informaton

 *					for detecting VBUS

 * @port:		gpio port number

 * @irq_work_fall	Structure for WorkQueue

 */

struct pch_vbus_gpio_data {

	int			port;

	struct work_struct	irq_work_fall;

};



/**

 * struct pch_udc_dev - Structure holding complete information

 *			of the PCH USB device
@@ -323,6 +341,7 @@ struct pch_udc_ep { 
 * @base_addr:		for mapped device memory

 * @irq:		IRQ line for the device

 * @cfg_data:		current cfg, intf, and alt in use

 * @vbus_gpio:		GPIO informaton for detecting VBUS

 */

struct pch_udc_dev {

	struct usb_gadget		gadget;
@@ -350,6 +369,7 @@ struct pch_udc_dev { 
	void __iomem			*base_addr;

	unsigned			irq;

	struct pch_udc_cfg_data		cfg_data;

	struct pch_vbus_gpio_data	vbus_gpio;

};



#define PCH_UDC_PCI_BAR			1
@@ -1225,6 +1245,115 @@ static const struct usb_gadget_ops pch_udc_ops = { 
	.stop	= pch_udc_stop,

};



/**

 * pch_vbus_gpio_get_value() - This API gets value of GPIO port as VBUS status.

 * @dev:	Reference to the driver structure

 *

 * Return value:

 *	1: VBUS is high

 *	0: VBUS is low

 *     -1: It is not enable to detect VBUS using GPIO

 */

static int pch_vbus_gpio_get_value(struct pch_udc_dev *dev)

{

	int vbus = 0;



	if (dev->vbus_gpio.port)

		vbus = gpio_get_value(dev->vbus_gpio.port) ? 1 : 0;

	else

		vbus = -1;



	return vbus;

}



/**

 * pch_vbus_gpio_work_fall() - This API keeps watch on VBUS becoming Low.

 *                             If VBUS is Low, disconnect is processed

 * @irq_work:	Structure for WorkQueue

 *

 */

static void pch_vbus_gpio_work_fall(struct work_struct *irq_work)

{

	struct pch_vbus_gpio_data *vbus_gpio = container_of(irq_work,

		struct pch_vbus_gpio_data, irq_work_fall);

	struct pch_udc_dev *dev =

		container_of(vbus_gpio, struct pch_udc_dev, vbus_gpio);

	int vbus_saved = -1;

	int vbus;

	int count;



	if (!dev->vbus_gpio.port)

		return;



	for (count = 0; count < (PCH_VBUS_PERIOD / PCH_VBUS_INTERVAL);

		count++) {

		vbus = pch_vbus_gpio_get_value(dev);



		if ((vbus_saved == vbus) && (vbus == 0)) {

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

			if (dev->driver

				&& dev->driver->disconnect) {

				dev->driver->disconnect(

					&dev->gadget);

			}

			pch_udc_reconnect(dev);

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

			return;

		}

		vbus_saved = vbus;

		mdelay(PCH_VBUS_INTERVAL);

	}

}



/**

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

 * @dev:	Reference to the driver structure

 * @vbus_gpio	Number of GPIO port to detect gpio

 *

 * Return codes:

 *	0: Success

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

 */

static int pch_vbus_gpio_init(struct pch_udc_dev *dev, int vbus_gpio_port)

{

	int err;



	dev->vbus_gpio.port = 0;



	if (vbus_gpio_port <= -1)

		return -EINVAL;



	err = gpio_is_valid(vbus_gpio_port);

	if (!err) {

		pr_err("%s: gpio port %d is invalid\n",

			__func__, vbus_gpio_port);

		return -EINVAL;

	}



	err = gpio_request(vbus_gpio_port, "pch_vbus");

	if (err) {

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

			__func__, vbus_gpio_port, err);

		return -EINVAL;

	}



	dev->vbus_gpio.port = vbus_gpio_port;

	gpio_direction_input(vbus_gpio_port);

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



	return 0;

}



/**

 * pch_vbus_gpio_free() - This API frees resources of GPIO port

 * @dev:	Reference to the driver structure

 */

static void pch_vbus_gpio_free(struct pch_udc_dev *dev)

{

	if (dev->vbus_gpio.port)

		gpio_free(dev->vbus_gpio.port);

}



/**

 * complete_req() - This API is invoked from the driver when processing

 *			of a request is complete
@@ -2510,6 +2639,8 @@ static void pch_udc_svc_cfg_interrupt(struct pch_udc_dev *dev) 
 */

static void pch_udc_dev_isr(struct pch_udc_dev *dev, u32 dev_intr)

{

	int vbus;



	/* USB Reset Interrupt */

	if (dev_intr & UDC_DEVINT_UR) {

		pch_udc_svc_ur_interrupt(dev);
@@ -2535,14 +2666,19 @@ static void pch_udc_dev_isr(struct pch_udc_dev *dev, u32 dev_intr) 
			spin_lock(&dev->lock);

		}



		if (dev->vbus_session == 0) {

		vbus = pch_vbus_gpio_get_value(dev);

		if ((dev->vbus_session == 0)

			&& (vbus != 1)) {

			if (dev->driver && dev->driver->disconnect) {

				spin_unlock(&dev->lock);

				dev->driver->disconnect(&dev->gadget);

				spin_lock(&dev->lock);

			}

			pch_udc_reconnect(dev);

		}

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

			&& (vbus == 1))

			schedule_work(&dev->vbus_gpio.irq_work_fall);



		dev_dbg(&dev->pdev->dev, "USB_SUSPEND\n");

	}

	/* Clear the SOF interrupt, if enabled */
@@ -2704,6 +2840,7 @@ static int pch_udc_pcd_init(struct pch_udc_dev *dev) 
{

	pch_udc_init(dev);

	pch_udc_pcd_reinit(dev);

	pch_vbus_gpio_init(dev, vbus_gpio_port);

	return 0;

}
@@ -2882,6 +3019,8 @@ static void pch_udc_remove(struct pci_dev *pdev) 
				 UDC_EP0OUT_BUFF_SIZE * 4, DMA_FROM_DEVICE);

	kfree(dev->ep0out_buf);



	pch_vbus_gpio_free(dev);



	pch_udc_exit(dev);



	if (dev->irq_registered)