Re: [PATCH v6 23/25] usb: chipidea: Pullup D+ in device mode via phy APIs

From: Peter Chen
Date: Tue Jan 03 2017 - 01:52:51 EST


On Wed, Dec 28, 2016 at 02:57:09PM -0800, Stephen Boyd wrote:
> If the phy supports it, call phy_set_mode() to pull up D+ when
> required by setting the mode to PHY_MODE_USB_DEVICE. If we want
> to remove the pullup, set the mode to PHY_MODE_USB_HOST.
>
> Cc: Peter Chen <peter.chen@xxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Stephen Boyd <stephen.boyd@xxxxxxxxxx>
> ---
> drivers/usb/chipidea/udc.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
> index 0d532a724d48..6d61fa0689b0 100644
> --- a/drivers/usb/chipidea/udc.c
> +++ b/drivers/usb/chipidea/udc.c
> @@ -18,6 +18,7 @@
> #include <linux/kernel.h>
> #include <linux/slab.h>
> #include <linux/pm_runtime.h>
> +#include <linux/phy/phy.h>
> #include <linux/usb/ch9.h>
> #include <linux/usb/gadget.h>
> #include <linux/usb/otg-fsm.h>
> @@ -1609,10 +1610,15 @@ static int ci_udc_pullup(struct usb_gadget *_gadget, int is_on)
> return 0;
>
> pm_runtime_get_sync(&ci->gadget.dev);
> - if (is_on)
> + if (is_on) {
> + if (ci->phy)
> + phy_set_mode(ci->phy, PHY_MODE_USB_DEVICE);
> hw_write(ci, OP_USBCMD, USBCMD_RS, USBCMD_RS);
> - else
> + } else {
> hw_write(ci, OP_USBCMD, USBCMD_RS, 0);
> + if (ci->phy)
> + phy_set_mode(ci->phy, PHY_MODE_USB_HOST);
> + }
> pm_runtime_put_sync(&ci->gadget.dev);
>
> return 0;
> --

Would you describe the use case for it? Why not adding it at
role switch routine?

--

Best Regards,
Peter Chen