From 637b78eb31e0b167ed913f1750bb645dfeda38f0 Mon Sep 17 00:00:00 2001 From: Tomoya MORINAGA Date: Fri, 3 Feb 2012 16:14:18 +0900 Subject: [PATCH] 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: Tomoya MORINAGA Signed-off-by: Felipe Balbi --- drivers/usb/gadget/pch_udc.c | 87 ++++++++++++++++++++++++++++++++++-- 1 file changed, 83 insertions(+), 4 deletions(-) diff --git a/drivers/usb/gadget/pch_udc.c b/drivers/usb/gadget/pch_udc.c index 9c5ae2c10147..a992084d3890 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; @@ -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; -- 2.20.1