From: ryan@bluewatersys•com (Ryan Mallon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/3] at91_udc: Add vbus polarity and polling mode
Date: Thu, 01 Jul 2010 09:02:05 +1200 [thread overview]
Message-ID: <4C2BB0CD.3020700@bluewatersys.com> (raw)
In-Reply-To: <1277699955-9931-3-git-send-email-ryan@bluewatersys.com>
On 06/28/2010 04:39 PM, Ryan Mallon wrote:
> Allow the vbus signal to optionally use polling. This is required if
> the vbus signal is connected to an non-interrupting io expander for
> example. If vbus is in polling mode, then it is assumed that the vbus
> gpio may sleep. Also add an option to have vbus be an active low
> signal. Both options are set in the platform data for the device.
>
> Signed-off-by: Ryan Mallon <ryan@bluewatersys•com>
Is anybody able to review this patch please? I have an ack for a patch
which depends on this one. This patch should have no impact (other than
slight code/data size increase) on existing users of the at91 udc driver
since it only adds an alternative code path for the case where vbus is
on a gpio which may sleep. The addition of the vbus polarity should also
not affect existing users since the default is active high.
Thanks,
~Ryan
> ---
> arch/arm/mach-at91/include/mach/board.h | 2 +
> drivers/usb/gadget/at91_udc.c | 66 +++++++++++++++++++++++++------
> drivers/usb/gadget/at91_udc.h | 2 +
> 3 files changed, 57 insertions(+), 13 deletions(-)
>
> diff --git a/arch/arm/mach-at91/include/mach/board.h b/arch/arm/mach-at91/include/mach/board.h
> index df2ed84..58528aa 100644
> --- a/arch/arm/mach-at91/include/mach/board.h
> +++ b/arch/arm/mach-at91/include/mach/board.h
> @@ -44,6 +44,8 @@
> /* USB Device */
> struct at91_udc_data {
> u8 vbus_pin; /* high == host powering us */
> + u8 vbus_active_low; /* vbus polarity */
> + u8 vbus_polled; /* Use polling, not interrupt */
> u8 pullup_pin; /* active == D+ pulled up */
> u8 pullup_active_low; /* true == pullup_pin is active low */
> };
> diff --git a/drivers/usb/gadget/at91_udc.c b/drivers/usb/gadget/at91_udc.c
> index eaa79c8..469a64c 100644
> --- a/drivers/usb/gadget/at91_udc.c
> +++ b/drivers/usb/gadget/at91_udc.c
> @@ -76,6 +76,7 @@
> static const char driver_name [] = "at91_udc";
> static const char ep0name[] = "ep0";
>
> +#define VBUS_POLL_TIMEOUT msecs_to_jiffies(1000)
>
> #define at91_udp_read(dev, reg) \
> __raw_readl((dev)->udp_baseaddr + (reg))
> @@ -1556,20 +1557,49 @@ static struct at91_udc controller = {
> /* ep6 and ep7 are also reserved (custom silicon might use them) */
> };
>
> +static void at91_vbus_update(struct at91_udc *udc, unsigned value)
> +{
> + if (udc->board.vbus_active_low)
> + value ^= 1;
> + if (value != udc->vbus)
> + at91_vbus_session(&udc->gadget, value);
> +}
> +
> static irqreturn_t at91_vbus_irq(int irq, void *_udc)
> {
> struct at91_udc *udc = _udc;
> - unsigned value;
>
> /* vbus needs at least brief debouncing */
> udelay(10);
> - value = gpio_get_value(udc->board.vbus_pin);
> - if (value != udc->vbus)
> - at91_vbus_session(&udc->gadget, value);
> + at91_vbus_update(udc, gpio_get_value(udc->board.vbus_pin));
>
> return IRQ_HANDLED;
> }
>
> +static void at91_vbus_timer_work(struct work_struct *work)
> +{
> + struct at91_udc *udc = container_of(work, struct at91_udc,
> + vbus_timer_work);
> +
> + at91_vbus_update(udc, gpio_get_value_cansleep(udc->board.vbus_pin));
> +
> + if (!timer_pending(&udc->vbus_timer))
> + mod_timer(&udc->vbus_timer, jiffies + VBUS_POLL_TIMEOUT);
> +}
> +
> +static void at91_vbus_timer(unsigned long data)
> +{
> + struct at91_udc *udc = (struct at91_udc *)data;
> +
> + /*
> + * If we are polling vbus it is likely that the gpio is on an
> + * bus such as i2c or spi which may sleep, so schedule some work
> + * to read the vbus gpio
> + */
> + if (!work_pending(&udc->vbus_timer_work))
> + schedule_work(&udc->vbus_timer_work);
> +}
> +
> int usb_gadget_register_driver (struct usb_gadget_driver *driver)
> {
> struct at91_udc *udc = &controller;
> @@ -1763,13 +1793,22 @@ static int __init at91udc_probe(struct platform_device *pdev)
> * Get the initial state of VBUS - we cannot expect
> * a pending interrupt.
> */
> - udc->vbus = gpio_get_value(udc->board.vbus_pin);
> - if (request_irq(udc->board.vbus_pin, at91_vbus_irq,
> - IRQF_DISABLED, driver_name, udc)) {
> - DBG("request vbus irq %d failed\n",
> - udc->board.vbus_pin);
> - retval = -EBUSY;
> - goto fail3;
> + if (udc->board.vbus_polled) {
> + udc->vbus = gpio_get_value_cansleep(udc->board.vbus_pin);
> + INIT_WORK(&udc->vbus_timer_work, at91_vbus_timer_work);
> + setup_timer(&udc->vbus_timer, at91_vbus_timer,
> + (unsigned long)udc);
> + mod_timer(&udc->vbus_timer,
> + jiffies + VBUS_POLL_TIMEOUT);
> + } else {
> + udc->vbus = gpio_get_value(udc->board.vbus_pin);
> + if (request_irq(udc->board.vbus_pin, at91_vbus_irq,
> + IRQF_DISABLED, driver_name, udc)) {
> + DBG("request vbus irq %d failed\n",
> + udc->board.vbus_pin);
> + retval = -EBUSY;
> + goto fail3;
> + }
> }
> } else {
> DBG("no VBUS detection, assuming always-on\n");
> @@ -1855,7 +1894,7 @@ static int at91udc_suspend(struct platform_device *pdev, pm_message_t mesg)
> enable_irq_wake(udc->udp_irq);
>
> udc->active_suspend = wake;
> - if (udc->board.vbus_pin > 0 && wake)
> + if (udc->board.vbus_pin > 0 && !udc->board.vbus_polled && wake)
> enable_irq_wake(udc->board.vbus_pin);
> return 0;
> }
> @@ -1864,7 +1903,8 @@ static int at91udc_resume(struct platform_device *pdev)
> {
> struct at91_udc *udc = platform_get_drvdata(pdev);
>
> - if (udc->board.vbus_pin > 0 && udc->active_suspend)
> + if (udc->board.vbus_pin > 0 && !udc->board.vbus_polled &&
> + udc->active_suspend)
> disable_irq_wake(udc->board.vbus_pin);
>
> /* maybe reconnect to host; if so, clocks on */
> diff --git a/drivers/usb/gadget/at91_udc.h b/drivers/usb/gadget/at91_udc.h
> index c65d622..a1f4f54 100644
> --- a/drivers/usb/gadget/at91_udc.h
> +++ b/drivers/usb/gadget/at91_udc.h
> @@ -144,6 +144,8 @@ struct at91_udc {
> struct proc_dir_entry *pde;
> void __iomem *udp_baseaddr;
> int udp_irq;
> + struct timer_list vbus_timer;
> + struct work_struct vbus_timer_work;
> };
>
> static inline struct at91_udc *to_udc(struct usb_gadget *g)
--
Bluewater Systems Ltd - ARM Technology Solution Centre
Ryan Mallon 5 Amuri Park, 404 Barbadoes St
ryan at bluewatersys.com PO Box 13 889, Christchurch 8013
http://www.bluewatersys.com New Zealand
Phone: +64 3 3779127 Freecall: Australia 1800 148 751
Fax: +64 3 3779135 USA 1800 261 2934
next prev parent reply other threads:[~2010-06-30 21:02 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-28 4:39 [PATCH 0/3] at91: Add support for Bluewater Systems Snapper 9260/9G20 modules Ryan Mallon
2010-06-28 4:39 ` [PATCH 1/3] AT91: Define NR_BUILTIN_GPIO Ryan Mallon
2010-06-28 5:41 ` avictor.za at gmail.com
2010-06-28 4:39 ` [PATCH 2/3] at91_udc: Add vbus polarity and polling mode Ryan Mallon
2010-06-30 21:02 ` Ryan Mallon [this message]
2010-07-01 13:45 ` Nicolas Ferre
2010-07-02 4:40 ` Ryan Mallon
2010-07-05 21:01 ` Ryan Mallon
2010-07-06 8:32 ` Nicolas Ferre
2010-06-28 4:39 ` [PATCH 3/3] at91: Add support for Bluewater Systems Snapper 9260/9G20 modules Ryan Mallon
2010-06-28 5:47 ` avictor.za at gmail.com
2010-06-28 9:17 ` Ryan Mallon
-- strict thread matches above, loose matches on Subject: below --
2010-06-16 21:20 [PATCH 0/3] at91: Add support for " Ryan Mallon
2010-06-16 21:20 ` [PATCH 2/3] at91_udc: Add vbus polarity and polling mode Ryan Mallon
2010-06-17 22:03 ` Ryan Mallon
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