Re: [PATCH v4 1/2] phy-sun4i-usb: Add full support for usb0 phy / OTG

[Kishon Vijay Abraham I <kishon-l0cyMroinI0@public.gmane.org>]

Hi,

On Thursday 11 June 2015 03:23 PM, Hans de Goede wrote:
> Hi,
>
> On 11-06-15 11:42, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>> On Sunday 31 May 2015 09:40 PM, Hans de Goede wrote:
>>> The usb0 phy is connected to an OTG controller, and as such needs some special
>>> handling:
>>>
>>> 1) It allows explicit control over the pullups, enable these on phy_init and
>>> disable them on phy_exit.
>>>
>>> 2) It has bits to signal id and vbus detect to the musb-core, add support for
>>> for monitoring id and vbus detect gpio-s for use in dual role mode, and set
>>> these bits to the correct values for operating in host only mode when no
>>> gpios are specified in the devicetree.
>>>
>>> 3) When in dual role mode the musb sunxi glue needs to know if the a host or
>>> device cable is plugged in, so when in dual role mode register an extcon.
>>>
>>> While updating the devicetree binding documentation also add documentation
>>> for the sofar undocumented usage of regulators for vbus for all 3 phys.
>>>
>>> Signed-off-by: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>>> ---
>>> Changes in v2:
>>> -Removed the sunxi specific phy functions, instead the id / vbus gpio polling
>>>    has been moved to the phy-sun4i-usb driver and their status is exported
>>>    through extcon for the sunxi-musb glue
>>> Changes in v3:
>>> -No changes
>>> Changes in v4:
>>> -Do not call regulator_disable in an unbalanced manner when an external vbus
>>>    is present
>>> ---
>>>    .../devicetree/bindings/phy/sun4i-usb-phy.txt      |  18 +-
>>>    drivers/phy/Kconfig                                |   1 +
>>>    drivers/phy/phy-sun4i-usb.c                        | 273 ++++++++++++++++++++-
>>>    3 files changed, 281 insertions(+), 11 deletions(-)
>>>
>> .
>> .
>> <snip>
>> .
>> .
>>> diff --git a/drivers/phy/phy-sun4i-usb.c b/drivers/phy/phy-sun4i-usb.c
>>> index 91c5be4..b45d707 100644
>>> --- a/drivers/phy/phy-sun4i-usb.c
>>> +++ b/drivers/phy/phy-sun4i-usb.c
>>> @@ -1,7 +1,7 @@
>>
>> .
>> .
>> <snip>
>> .
>> .
>>>    static struct phy *sun4i_usb_phy_xlate(struct device *dev,
>>>                        struct of_phandle_args *args)
>>>    {
>>> @@ -240,13 +417,20 @@ static int sun4i_usb_phy_probe(struct platform_device *pdev)
>>>        struct phy_provider *phy_provider;
>>>        bool dedicated_clocks;
>>>        struct resource *res;
>>> -    int i;
>>> +    int i, ret;
>>>
>>>        data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>>>        if (!data)
>>>            return -ENOMEM;
>>>
>>>        mutex_init(&data->mutex);
>>> +    INIT_DELAYED_WORK(&data->detect, sun4i_usb_phy0_id_vbus_det_scan);
>>> +    data->extcon_cable_names[0] = extcon_cable_name[EXTCON_USB_HOST];
>>> +    data->extcon_cable_names[1] = extcon_cable_name[EXTCON_USB];
>>> +    data->extcon_cable_names[2] = NULL;
>>> +    data->extcon.name = DRIVER_NAME;
>>> +    data->extcon.supported_cable = data->extcon_cable_names;
>>> +    data->extcon.dev.parent = dev;
>>>
>>>        if (of_device_is_compatible(np, "allwinner,sun5i-a13-usb-phy"))
>>>            data->num_phys = 2;
>>> @@ -269,6 +453,34 @@ static int sun4i_usb_phy_probe(struct platform_device *pdev)
>>>        if (IS_ERR(data->base))
>>>            return PTR_ERR(data->base);
>>>
>>> +    data->id_det_gpio = devm_gpiod_get(dev, "usb0_id_det", GPIOD_IN);
>>> +    if (IS_ERR(data->id_det_gpio)) {
>>> +        if (PTR_ERR(data->id_det_gpio) == -EPROBE_DEFER)
>>> +            return -EPROBE_DEFER;
>>> +        data->id_det_gpio = NULL;
>>> +    }
>>> +
>>> +    data->vbus_det_gpio = devm_gpiod_get(dev, "usb0_vbus_det", GPIOD_IN);
>>> +    if (IS_ERR(data->vbus_det_gpio)) {
>>> +        if (PTR_ERR(data->vbus_det_gpio) == -EPROBE_DEFER)
>>> +            return -EPROBE_DEFER;
>>> +        data->vbus_det_gpio = NULL;
>>> +    }
>>> +
>>> +    /* We either want both gpio pins or neither (when in host mode) */
>>> +    if (!data->id_det_gpio != !data->vbus_det_gpio) {
>>> +        dev_err(dev, "failed to get id or vbus detect pin\n");
>>> +        return -ENODEV;
>>> +    }
>>> +
>>> +    if (data->id_det_gpio) {
>>> +        ret = devm_extcon_dev_register(dev, &data->extcon);
>>> +        if (ret) {
>>> +            dev_err(dev, "failed to register extcon: %d\n", ret);
>>> +            return ret;
>>> +        }
>>> +    }
>>> +
>>>        for (i = 0; i < data->num_phys; i++) {
>>>            struct sun4i_usb_phy *phy = data->phys + i;
>>>            char name[16];
>>> @@ -318,12 +530,54 @@ static int sun4i_usb_phy_probe(struct platform_device *pdev)
>>>            phy_set_drvdata(phy->phy, &data->phys[i]);
>>>        }
>>>
>>> +    data->id_det_irq = gpiod_to_irq(data->id_det_gpio);
>>> +    data->vbus_det_irq = gpiod_to_irq(data->vbus_det_gpio);
>>> +    if (data->id_det_irq  < 0 || data->vbus_det_irq < 0)
>>> +        data->phy0_poll = true;
>>
>> if polling is enabled, we shouldn't enable irq at all?
>
> Thanks for the review.
>
> One some boards one of the gpio-s is irq capable and the other
> is not, in which case the current code indeed enables both
> irq handling for the one gpio which is irq capable and enables
> polling. This is done this way deliberately as the irq path
> has much better latency then polling and the 2 can co-exist.

okay. Would be good to have this as a comment.
>
>>> +
>>> +    if (data->id_det_irq >= 0) {
>>> +        ret = devm_request_irq(dev, data->id_det_irq,
>>> +                sun4i_usb_phy0_id_vbus_det_irq,
>>> +                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
>>> +                "usb0-id-det", data);
>>> +        if (ret) {
>>> +            dev_err(dev, "Err requesting id-det-irq: %d\n", ret);
>>> +            return ret;
>>> +        }
>>> +    }
>>> +
>>> +    if (data->vbus_det_irq >= 0) {
>>> +        ret = devm_request_irq(dev, data->vbus_det_irq,
>>> +                sun4i_usb_phy0_id_vbus_det_irq,
>>> +                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
>>> +                "usb0-vbus-det", data);
>>> +        if (ret) {
>>> +            dev_err(dev, "Err requesting vbus-det-irq: %d\n", ret);
>>> +            return ret;
>>> +        }
>>> +    }
>>> +
>>>        dev_set_drvdata(dev, data);
>>>        phy_provider = devm_of_phy_provider_register(dev, sun4i_usb_phy_xlate);
>>>
>>>        return PTR_ERR_OR_ZERO(phy_provider);
>>>    }
>>>
>>> +static int sun4i_usb_phy_remove(struct platform_device *pdev)
>>> +{
>>> +    struct device *dev = &pdev->dev;
>>> +    struct sun4i_usb_phy_data *data = dev_get_drvdata(dev);
>>> +
>>> +    if (data->id_det_irq >= 0)
>>> +        devm_free_irq(dev, data->id_det_irq, data);
>>> +    if (data->vbus_det_irq >= 0)
>>> +        devm_free_irq(dev, data->vbus_det_irq, data);
>>
>> This shouldn't be needed since you already use devm_* in probe.
>
> The use of devm_* in probe helps to keep the error handling in
> probe sane, but we must explicitly free the irqs here, otherwise
> they may trigger after this:

 From whatever I know free irq will be invoked in remove if devm_request_irq is 
used in probe. I have to check though.

Thanks
Kishon