From mboxrd@z Thu Jan  1 00:00:00 1970
From: hdegoede@redhat.com (Hans de Goede)
Date: Mon, 22 Aug 2016 17:08:56 +0200
Subject: [PATCH v2 7/7] musb: sunxi: Add support for platform_set_mode
In-Reply-To: <20160822141158.GF1853@uda0271908>
References: <1471288892-21702-1-git-send-email-hdegoede@redhat.com>
 <1471288892-21702-8-git-send-email-hdegoede@redhat.com>
 <20160819213049.GC1853@uda0271908>
 <2a55a1bf-7ebf-3ab4-b231-85eba20103f1@redhat.com>
 <20160822141158.GF1853@uda0271908>
Message-ID: <9699b62e-421a-ae8e-c25e-ef48beb84ce0@redhat.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hi,

On 22-08-16 16:11, Bin Liu wrote:
> Hi,
>
> On Sun, Aug 21, 2016 at 12:10:26PM +0200, Hans de Goede wrote:
>> Hi,
>>
>> On 19-08-16 23:30, Bin Liu wrote:
>>> Hi,
>>>
>>> On Mon, Aug 15, 2016 at 09:21:32PM +0200, Hans de Goede wrote:
>>>> This allows run-time dr_mode switching support via the "mode" musb
>>>> sysfs attribute.
>>>>
>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>> ---
>>>> drivers/usb/musb/sunxi.c | 52 ++++++++++++++++++++++++++++++++++++++++++++----
>>>> 1 file changed, 48 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/drivers/usb/musb/sunxi.c b/drivers/usb/musb/sunxi.c
>>>> index c6ee166..1fe7451 100644
>>>> --- a/drivers/usb/musb/sunxi.c
>>>> +++ b/drivers/usb/musb/sunxi.c
>>>> @@ -74,6 +74,7 @@
>>>> #define SUNXI_MUSB_FL_HAS_SRAM			5
>>>> #define SUNXI_MUSB_FL_HAS_RESET			6
>>>> #define SUNXI_MUSB_FL_NO_CONFIGDATA		7
>>>> +#define SUNXI_MUSB_FL_PHY_MODE_PEND		8
>>>>
>>>> /* Our read/write methods need access and do not get passed in a musb ref :| */
>>>> static struct musb *sunxi_musb;
>>>> @@ -87,6 +88,7 @@ struct sunxi_glue {
>>>> 	struct phy		*phy;
>>>> 	struct platform_device	*usb_phy;
>>>> 	struct usb_phy		*xceiv;
>>>> +	enum phy_mode		phy_mode;
>>>> 	unsigned long		flags;
>>>> 	struct work_struct	work;
>>>> 	struct extcon_dev	*extcon;
>>>> @@ -140,6 +142,9 @@ static void sunxi_musb_work(struct work_struct *work)
>>>> 			clear_bit(SUNXI_MUSB_FL_PHY_ON, &glue->flags);
>>>> 		}
>>>> 	}
>>>> +
>>>> +	if (test_and_clear_bit(SUNXI_MUSB_FL_PHY_MODE_PEND, &glue->flags))
>>>> +		phy_set_mode(glue->phy, glue->phy_mode);
>>>> }
>>>>
>>>> static void sunxi_musb_set_vbus(struct musb *musb, int is_on)
>>>> @@ -341,6 +346,41 @@ static void sunxi_musb_dma_controller_destroy(struct dma_controller *c)
>>>> {
>>>> }
>>>>
>>>> +static int sunxi_musb_set_mode(struct musb *musb, u8 mode)
>>>> +{
>>>> +	struct sunxi_glue *glue = dev_get_drvdata(musb->controller->parent);
>>>> +	enum phy_mode new_mode;
>>>> +
>>>> +	switch (mode) {
>>>> +	case MUSB_HOST:		new_mode = PHY_MODE_USB_HOST; break;
>>>> +	case MUSB_PERIPHERAL:	new_mode = PHY_MODE_USB_DEVICE; break;
>>>> +	case MUSB_OTG:		new_mode = PHY_MODE_USB_OTG; break;
>>>
>>> Please fix the code style as commented in patch 4/7.
>>
>> Ok I will send a new version with this fixed.
>>
>>>
>>>> +	default:
>>>> +		dev_err(musb->controller->parent,
>>>> +			"Error requested mode not supported by this kernel\n");
>>>> +		return -EINVAL;
>>>> +	}
>>>> +
>>>> +	if (glue->phy_mode == new_mode)
>>>> +		return 0;
>>>> +
>>>> +	if (musb->port_mode != MUSB_PORT_MODE_DUAL_ROLE) {
>>>> +		dev_err(musb->controller->parent,
>>>> +			"Error changing modes is only supported in dual role mode\n");
>>>> +		return -EINVAL;
>>>> +	}
>>>> +
>>>> +	/*
>>>> +	 * phy_set_mode may sleep, and we're called with a spinlock held,
>>>> +	 * so let sunxi_musb_work deal with it.
>>>> +	 */
>>>> +	glue->phy_mode = new_mode;
>>>> +	set_bit(SUNXI_MUSB_FL_PHY_MODE_PEND, &glue->flags);
>>>> +	schedule_work(&glue->work);
>>>
>>> When switching from host to peripheral mode, if an usb device is still
>>> plugged and enumerated, how do you handle the device disconnect?
>>
>> The phy code will report vbus low for long enough for the musb to end
>> the current session. It already does this for boards which do not
>> have working vbus detection.
>
> But you didn't disconnect DP/DM, right? then musb detects vbus is gone
> without receiving disconnect event, this is vbus error case, not a normal
> teardown.

Correct, there is no way to disconnect DP/DM and reporting Vbus low for
a while does the trick.

Regards,

Hans