pt., 29 mar 2019 o 10:33 Bartosz Golaszewski <brgl@xxxxxxxx> napisał(a):
>
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
>
> Historically the power supply management in this driver has been handled
> in two separate places in parallel. Device-tree users simply defined an
> appropriate regulator, while two boards with no DT support (da830-evm and
> omapl138-hawk) passed functions defined in their respective board files
> over platform data. These functions simply used legacy GPIO calls to
> watch the oc GPIO for interrupts and disable the vbus GPIO when the irq
> fires.
>
> Commit d193abf1c913 ("usb: ohci-da8xx: add vbus and overcurrent gpios")
> updated these GPIO calls to the modern API and moved them inside the
> driver.
>
> This however is not the optimal solution for the vbus GPIO which should
> be modeled as a fixed regulator that can be controlled with a GPIO.
>
> In order to keep the overcurrent protection available once we move the
> board files to using fixed regulators we need to disable the enable_reg
> regulator when the overcurrent indicator interrupt fires. Since we
> cannot call regulator_disable() from interrupt context, we need to
> switch to using a oneshot threaded interrupt.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> ---
> drivers/usb/host/ohci-da8xx.c | 29 ++++++++++++++++++++++++-----
> 1 file changed, 24 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/host/ohci-da8xx.c b/drivers/usb/host/ohci-da8xx.c
> index 9c6d1f03b871..35eb2cb96a8f 100644
> --- a/drivers/usb/host/ohci-da8xx.c
> +++ b/drivers/usb/host/ohci-da8xx.c
> @@ -206,8 +206,25 @@ static irqreturn_t ohci_da8xx_oc_handler(int irq, void *data)
> {
> struct da8xx_ohci_hcd *da8xx_ohci = data;
>
> - if (gpiod_get_value(da8xx_ohci->oc_gpio))
> - gpiod_set_value(da8xx_ohci->vbus_gpio, 0);
> + if (gpiod_get_value(da8xx_ohci->oc_gpio)) {
> + if (da8xx_ohci->vbus_gpio)
> + gpiod_set_value(da8xx_ohci->vbus_gpio, 0);
> + else if (da8xx_ohci->vbus_reg)
> + return IRQ_WAKE_THREAD;
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t ohci_da8xx_oc_thread(int irq, void *data)
> +{
> + struct da8xx_ohci_hcd *da8xx_ohci = data;
> + struct device *dev = da8xx_ohci->hcd->self.controller;
> + int ret;
> +
> + ret = regulator_disable(da8xx_ohci->vbus_reg);
> + if (ret)
> + dev_err(dev, "Failed to disable regulator: %d\n", ret);
>
> return IRQ_HANDLED;
> }
> @@ -434,9 +451,11 @@ static int ohci_da8xx_probe(struct platform_device *pdev)
> if (oc_irq < 0)
> goto err;
>
> - error = devm_request_irq(dev, oc_irq, ohci_da8xx_oc_handler,
> - IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> - "OHCI over-current indicator", da8xx_ohci);
> + error = devm_request_threaded_irq(dev, oc_irq,
> + ohci_da8xx_oc_handler, ohci_da8xx_oc_thread,
> + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
> + IRQF_ONESHOT, "OHCI over-current indicator",
> + da8xx_ohci);
Ugh I noticed a problem with this patch if the module is built-in -
after calling devm_request_threaded_irq() any subsequent msleep() will
hang. This doesn't happen if the driver is built as a module. I'm not
sure what the reason is yet.
Bart
> if (error)
> goto err;
> }
> --
> 2.21.0
>
