Re: [PATCH 3/4] extcon: usb-gpio: make debounce value configurable in devicetree

Robert Baldyga
2015-03-31T12:17:07Z

On 03/31/2015 11:30 AM, Roger Quadros wrote:
> On 31/03/15 10:46, Robert Baldyga wrote:
>> This patch adds devicetree property for setting debounce value. It allows
>> to set debounce time shorter or longer depending on the needs of given
>> platform.
>>
>> Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
>> ---
>> drivers/extcon/extcon-usb-gpio.c | 14 +++++++++-----
>> 1 file changed, 9 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
>> index 02ff40e..86e3ece 100644
>> --- a/drivers/extcon/extcon-usb-gpio.c
>> +++ b/drivers/extcon/extcon-usb-gpio.c
>> @@ -130,6 +130,7 @@ static int usb_extcon_probe(struct platform_device *pdev)
>> struct device *dev = &pdev->dev;
>> struct device_node *np = dev->of_node;
>> struct usb_extcon_info *info;
>> + u32 debounce;
>> int ret;
>>
>> if (!np)
>> @@ -140,6 +141,11 @@ static int usb_extcon_probe(struct platform_device *pdev)
>> return -ENOMEM;
>>
>> info->dev = dev;
>> +
>> + ret = of_property_read_u32(np, "debounce", &debounce);
>> + if (ret < 0)
>> + debounce = USB_GPIO_DEBOUNCE_MS;
>> +
>
> Should we sanity check debounce value provided by device tree?
> e.g. if it is greater than USB_GPIO_DEBOUNCE_MAX then we error out.
> MAX could be 100 or 250ms.
>

None of extcon drivers do such thing, so I suppose it's up to devicetree
to supply reasonable value here.

>> info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id");
>> info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus");
>>
>> @@ -161,16 +167,14 @@ static int usb_extcon_probe(struct platform_device *pdev)
>> }
>>
>> if (info->id_gpiod)
>> - ret = gpiod_set_debounce(info->id_gpiod,
>> - USB_GPIO_DEBOUNCE_MS * 1000);
>> + ret = gpiod_set_debounce(info->id_gpiod, debounce * 1000);
>> if (!ret && info->vbus_gpiod) {
>> - ret = gpiod_set_debounce(info->vbus_gpiod,
>> - USB_GPIO_DEBOUNCE_MS * 1000);
>> + ret = gpiod_set_debounce(info->vbus_gpiod, debounce * 1000);
>> if (ret < 0 && info->id_gpiod)
>> gpiod_set_debounce(info->vbus_gpiod, 0);
>> }
>> if (ret < 0)
>> - info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);
>> + info->debounce_jiffies = msecs_to_jiffies(debounce);
>>
>> INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);
>>
>>

Best regards,
Robert Baldyga