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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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      Last update: 2012-02-09 09:01    [W:0.035 / U:60.024 seconds]
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