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Date:   Mon, 6 Jul 2020 15:16:31 -0700
From:   Prashant Malani <pmalani@chromium.org>
To:     Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc:     Benson Leung <bleung@chromium.org>,
        Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        Guenter Roeck <groeck@chromium.org>,
        "Mani, Rajmohan" <rajmohan.mani@intel.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] platform/chrome: cros_ec_typec: USB4 support
Message-ID: <20200706221631.GA68629@google.com>
References: <20200703081703.87720-1-heikki.krogerus@linux.intel.com>
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In-Reply-To: <20200703081703.87720-1-heikki.krogerus@linux.intel.com>
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Hi Heikki,

On Fri, Jul 03, 2020 at 11:17:03AM +0300, Heikki Krogerus wrote:
> With USB4 mode the mux driver needs the Enter_USB Data
> Object (EUDO) that was used when the USB mode was entered.
> Though the object is not available in the driver, it is
> possible to construct it from the information we have.
> 
> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> ---
> Hi,
> 
> This patch depends on latest usb-next from Greg KH, this commit in
> particular:
> https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/commit/?h=usb-next&id=ad8db94d6813dc659bd4de0531a8a1150559eafb
> 
> Prashant, can you take over the development of this patch (in case it
> still needs work)? I will take a few weeks vacation starting from next
> week (July 6th).

Sure. Have a nice vacation! :)

> I was hoping to get this feature into v5.9 if that's
> possible. But if you guys think there is no hurry, let's forget about
> it. Then we can just wait for 5.9-rc1 and not worry about the
> dependency on Greg's usb-next.
> 
> thanks,
> 
> ---
>  drivers/platform/chrome/cros_ec_typec.c | 42 ++++++++++++++++++++++++-
>  1 file changed, 41 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
> index 0c041b79cbbac..c9713aab9b6b0 100644
> --- a/drivers/platform/chrome/cros_ec_typec.c
> +++ b/drivers/platform/chrome/cros_ec_typec.c
> @@ -13,6 +13,7 @@
>  #include <linux/platform_data/cros_ec_proto.h>
>  #include <linux/platform_data/cros_usbpd_notify.h>
>  #include <linux/platform_device.h>
> +#include <linux/usb/pd.h>
>  #include <linux/usb/typec.h>
>  #include <linux/usb/typec_altmode.h>
>  #include <linux/usb/typec_dp.h>
> @@ -494,6 +495,43 @@ static int cros_typec_enable_dp(struct cros_typec_data *typec,
>  	return typec_mux_set(port->mux, &port->state);
>  }
>  
> +static int cros_typec_enable_usb4(struct cros_typec_data *typec,
> +				  int port_num,
> +				  struct ec_response_usb_pd_control_v2 *pd_ctrl)
> +{
> +	struct cros_typec_port *port = typec->ports[port_num];
> +	struct enter_usb_data data;
> +
> +	data.eudo = EUDO_USB_MODE_USB4 << EUDO_USB_MODE_SHIFT;
> +
> +	/* Cable Speed */
> +	data.eudo |= pd_ctrl->cable_speed << EUDO_CABLE_SPEED_SHIFT;
> +
> +	/* Cable Type */
> +	if (pd_ctrl->control_flags & USB_PD_CTRL_OPTICAL_CABLE)
> +		data.eudo |= EUDO_CABLE_TYPE_OPTICAL << EUDO_CABLE_TYPE_SHIFT;
> +	else if (pd_ctrl->control_flags & USB_PD_CTRL_ACTIVE_CABLE)
> +		data.eudo |= EUDO_CABLE_TYPE_RE_TIMER << EUDO_CABLE_TYPE_SHIFT;
> +
> +	/* REVISIT: Cable Current? */
> +
> +	/* REVISIT: Claiming unconditionally that all tunnels are supported. */
> +	data.eudo |= EUDO_PCIE_SUPPORT;
> +	data.eudo |= EUDO_DP_SUPPORT;
> +
> +	data.eudo |= EUDO_TBT_SUPPORT;
> +	data.eudo |= EUDO_HOST_PRESENT;
> +
> +	data.active_link_training = !!(pd_ctrl->control_flags &
> +				       USB_PD_CTRL_ACTIVE_LINK_UNIDIR);
> +
> +	port->state.alt = NULL;
> +	port->state.data = &data;
> +	port->state.mode = TYPEC_MODE_USB4;
> +
> +	return typec_mux_set(port->mux, &port->state);
> +}
> +
>  static int cros_typec_configure_mux(struct cros_typec_data *typec, int port_num,
>  				uint8_t mux_flags,
>  				struct ec_response_usb_pd_control_v2 *pd_ctrl)
> @@ -514,7 +552,9 @@ static int cros_typec_configure_mux(struct cros_typec_data *typec, int port_num,
>  	if (ret)
>  		return ret;
>  
> -	if (mux_flags & USB_PD_MUX_TBT_COMPAT_ENABLED) {
> +	if (mux_flags & USB_PD_MUX_USB4_ENABLED) {
> +		ret = cros_typec_enable_usb4(typec, port_num, pd_ctrl);
> +	} else if (mux_flags & USB_PD_MUX_TBT_COMPAT_ENABLED) {
>  		ret = cros_typec_enable_tbt(typec, port_num, pd_ctrl);
>  	} else if (mux_flags & USB_PD_MUX_DP_ENABLED) {
>  		ret = cros_typec_enable_dp(typec, port_num, pd_ctrl);
> -- 
> 2.27.0
>