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usb: gadget: pch_udc: Detecting VBUS through GPIO with interrupt

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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: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Tomoya MORINAGA 2012-02-03 16:14:18 +09:00 committed by Felipe Balbi
parent dd63180b75
commit 637b78eb31
1 changed files with 83 additions and 4 deletions
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87
drivers/usb/gadget/pch_udc.c
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@ -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);
}
pch_udc_reconnect(dev);
dev_dbg(&dev->pdev->dev, "VBUS fell");
if (dev->vbus_gpio.intr)
pch_udc_init(dev);
else
pch_udc_reconnect(dev);
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");
@ -2941,7 +3019,8 @@ static int pch_udc_start(struct usb_gadget_driver *driver,
pch_udc_setup_ep0(dev);
/* clear SD */
pch_udc_clear_disconnect(dev);
if ((pch_vbus_gpio_get_value(dev) != 0) || !dev->vbus_gpio.intr)
pch_udc_clear_disconnect(dev);
dev->connected = 1;
return 0;