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SubjectRe: [PATCH 2/3] pch_udc: Detecting VBUS through GPIO with interrupt
On Fri, Feb 03, 2012 at 04:14:18PM +0900, Tomoya MORINAGA wrote:
> 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'.
>
> Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
> ---
> drivers/usb/gadget/pch_udc.c | 85 ++++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 82 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/gadget/pch_udc.c b/drivers/usb/gadget/pch_udc.c
> index d77211c..942fe92 100644
> --- a/drivers/usb/gadget/pch_udc.c
> +++ b/drivers/usb/gadget/pch_udc.c
> @@ -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;
> @@ -1306,6 +1312,57 @@ 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
> * @vbus_gpio Number of GPIO port to detect gpio
> @@ -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);
> }
> @@ -2677,6 +2754,7 @@ 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))
> + &&!dev->vbus_gpio.intr)

This causes a compile error which I have fixed this time. Next time I
will silently drop the patch:

diff --git a/drivers/usb/gadget/pch_udc.c b/drivers/usb/gadget/pch_udc.c
index fb74cc8..a992084 100644
--- a/drivers/usb/gadget/pch_udc.c
+++ b/drivers/usb/gadget/pch_udc.c
@@ -2753,8 +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))
- &&!dev->vbus_gpio.intr)
+ && (vbus == 1)
+ && !dev->vbus_gpio.intr)
schedule_work(&dev->vbus_gpio.irq_work_fall);

dev_dbg(&dev->pdev->dev, "USB_SUSPEND\n");
--
balbi
[unhandled content-type:application/pgp-signature]
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