RE: [PATCH v2] phy: rcar-gen3-usb2: add sysfs for usb role swap

2016-11-01 Thread Yoshihiro Shimoda 
Hi Peter,

> From: Peter Chen [mailto:hzpeterc...@gmail.com]
> Sent: Tuesday, November 01, 2016 8:38 PM
> 
> On Tue, Nov 01, 2016 at 04:01:58PM +0900, Yoshihiro Shimoda wrote:
> > This patch adds sysfs "otg_inputs" for usb role swap. This parameter
> > is write-only and if you use them as the following, you can swap
> > the usb role.
> >
> > For example:
> >  1) connect a usb cable using 2 salvator-x boards
> >  2) On A-device (as host), you input the following command:
> ># echo a_bus_req/ > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs
> >  3) On B-device (as peripheral), you input the following command:
> ># echo b_bus_req > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs
> >
> > Then, the A-device acts as a peripheral (A-peripheral) and the B-device
> > acts as a host (B-host).
> > Please note that A-device must input the following command if you
> > want the board to act as a host again. (even if you disconnect the usb
> > cable, since id state may be the same, the condition keeps "A-peripheral".)
> >  # echo a_bus_drop > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs
> >
> > Also you can use the following command if you want the B-device board to
> > act as a peripheral again.
> >  # echo b_bus_req/ > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs
> >
> > Signed-off-by: Yoshihiro Shimoda 
> > ---
> >  This patch is based on the latest linux-phy.git / next branch.
> >  (commit id = 7809cd2ce6abd4f431e4b14e6b1276a7cc842ac4)
> >
> >  Since this patch is related to usb, I added email addresses of Greg, 
> > Felipe,
> >  Peter and USB ML as CC. (This patch doesn't use USB OTG FSM though.)
> >
> >  Changed from v1:
> >   - rebase the latest next branch.
> >
> >  .../ABI/testing/sysfs-platform-phy-rcar-gen3-usb2  |  11 ++
> >  drivers/phy/phy-rcar-gen3-usb2.c   | 124 
> > -
> >  2 files changed, 134 insertions(+), 1 deletion(-)
> >  create mode 100644 
> > Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2
> >
> > diff --git a/Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2
> b/Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2
> > new file mode 100644
> > index 000..c7e715af
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2
> > @@ -0,0 +1,11 @@
> > +What:  /sys/devices/platform//otg-inputs
> > +Date:  October 2016
> > +KernelVersion: 4.10
> > +Contact:   Yoshihiro Shimoda 
> > +Description:
> > +   This write-only file changes the phy mode for role swap of usb.
> > +   This file accepts the following strings:
> > +"a_bus_req/" - switching from A-Host to A-Peripheral
> > +"a_bus_drop" - switching from A-Peripheral to A-Host
> > +"b_bus_req"  - switching from B-Peripheral to B-Host
> > +"b_bus_req/" - switching from B-Host to B-Peripheral
> 
> Would you really care OTG FSM state machine? If not, you could just use
> "host" and "peripheral" to stand for current USB role, and implement
> role switch sysfs like: /sys/devices/platform//role.

Thank you for the comment!
Since I would not care OTG FSM state machine for now, I will modify the patch to
use "host" and "peripheral" that you suggested.

Best regards,
Yoshihiro Shimoda

> Peter
>

Re: [PATCH v2] phy: rcar-gen3-usb2: add sysfs for usb role swap

2016-11-01 Thread Peter Chen 
On Tue, Nov 01, 2016 at 04:01:58PM +0900, Yoshihiro Shimoda wrote:
> This patch adds sysfs "otg_inputs" for usb role swap. This parameter
> is write-only and if you use them as the following, you can swap
> the usb role.
> 
> For example:
>  1) connect a usb cable using 2 salvator-x boards
>  2) On A-device (as host), you input the following command:
># echo a_bus_req/ > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs
>  3) On B-device (as peripheral), you input the following command:
># echo b_bus_req > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs
> 
> Then, the A-device acts as a peripheral (A-peripheral) and the B-device
> acts as a host (B-host).
> Please note that A-device must input the following command if you
> want the board to act as a host again. (even if you disconnect the usb
> cable, since id state may be the same, the condition keeps "A-peripheral".)
>  # echo a_bus_drop > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs
> 
> Also you can use the following command if you want the B-device board to
> act as a peripheral again.
>  # echo b_bus_req/ > /sys/devices/platform/soc/ee080200.usb-phy/otg_inputs
> 
> Signed-off-by: Yoshihiro Shimoda 
> ---
>  This patch is based on the latest linux-phy.git / next branch.
>  (commit id = 7809cd2ce6abd4f431e4b14e6b1276a7cc842ac4)
> 
>  Since this patch is related to usb, I added email addresses of Greg, Felipe,
>  Peter and USB ML as CC. (This patch doesn't use USB OTG FSM though.)
> 
>  Changed from v1:
>   - rebase the latest next branch.
> 
>  .../ABI/testing/sysfs-platform-phy-rcar-gen3-usb2  |  11 ++
>  drivers/phy/phy-rcar-gen3-usb2.c   | 124 
> -
>  2 files changed, 134 insertions(+), 1 deletion(-)
>  create mode 100644 
> Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2
> 
> diff --git a/Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2 
> b/Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2
> new file mode 100644
> index 000..c7e715af
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-platform-phy-rcar-gen3-usb2
> @@ -0,0 +1,11 @@
> +What:/sys/devices/platform//otg-inputs
> +Date:October 2016
> +KernelVersion:   4.10
> +Contact: Yoshihiro Shimoda 
> +Description:
> + This write-only file changes the phy mode for role swap of usb.
> + This file accepts the following strings:
> +  "a_bus_req/" - switching from A-Host to A-Peripheral
> +  "a_bus_drop" - switching from A-Peripheral to A-Host
> +  "b_bus_req"  - switching from B-Peripheral to B-Host
> +  "b_bus_req/" - switching from B-Host to B-Peripheral

Would you really care OTG FSM state machine? If not, you could just use
"host" and "peripheral" to stand for current USB role, and implement
role switch sysfs like: /sys/devices/platform//role.

Peter

> diff --git a/drivers/phy/phy-rcar-gen3-usb2.c 
> b/drivers/phy/phy-rcar-gen3-usb2.c
> index 3d97ead..80f5bcc 100644
> --- a/drivers/phy/phy-rcar-gen3-usb2.c
> +++ b/drivers/phy/phy-rcar-gen3-usb2.c
> @@ -70,6 +70,7 @@
>  #define USB2_LINECTRL1_DP_RPDBIT(18)
>  #define USB2_LINECTRL1_DMRPD_EN  BIT(17)
>  #define USB2_LINECTRL1_DM_RPDBIT(16)
> +#define USB2_LINECTRL1_OPMODE_NODRV  BIT(6)
>  
>  /* ADPCTRL */
>  #define USB2_ADPCTRL_OTGSESSVLD  BIT(20)
> @@ -161,6 +162,43 @@ static void rcar_gen3_init_for_peri(struct 
> rcar_gen3_chan *ch)
>   schedule_work(>work);
>  }
>  
> +static void rcar_gen3_init_for_b_host(struct rcar_gen3_chan *ch)
> +{
> + void __iomem *usb2_base = ch->base;
> + u32 val;
> +
> + val = readl(usb2_base + USB2_LINECTRL1);
> + writel(val | USB2_LINECTRL1_OPMODE_NODRV, usb2_base + USB2_LINECTRL1);
> +
> + rcar_gen3_set_linectrl(ch, 1, 1);
> + rcar_gen3_set_host_mode(ch, 1);
> + rcar_gen3_enable_vbus_ctrl(ch, 0);
> +
> + val = readl(usb2_base + USB2_LINECTRL1);
> + writel(val & ~USB2_LINECTRL1_OPMODE_NODRV, usb2_base + USB2_LINECTRL1);
> +}
> +
> +static void rcar_gen3_init_for_a_peri(struct rcar_gen3_chan *ch)
> +{
> + rcar_gen3_set_linectrl(ch, 0, 1);
> + rcar_gen3_set_host_mode(ch, 0);
> + rcar_gen3_enable_vbus_ctrl(ch, 1);
> +}
> +
> +static void rcar_gen3_init_from_a_peri_to_a_host(struct rcar_gen3_chan *ch)
> +{
> + void __iomem *usb2_base = ch->base;
> + u32 val;
> +
> + val = readl(usb2_base + USB2_OBINTEN);
> + writel(val & ~USB2_OBINT_BITS, usb2_base + USB2_OBINTEN);
> +
> + rcar_gen3_enable_vbus_ctrl(ch, 0);
> + rcar_gen3_init_for_host(ch);
> +
> + writel(val | USB2_OBINT_BITS, usb2_base + USB2_OBINTEN);
> +}
> +
>  static bool rcar_gen3_check_id(struct rcar_gen3_chan *ch)
>  {
>   return !!(readl(ch->base + USB2_ADPCTRL) & USB2_ADPCTRL_IDDIG);
> @@ -174,6 +212,71 @@ static void