linux-kernel - Re: [PATCH 2/4] usb: typec: mux: intel_pmc_mux: Support for static SBU/HSL orientation

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Message-ID: <20200507224041.GA247416@google.com>
Date:   Thu, 7 May 2020 15:40:41 -0700
From:   Prashant Malani <pmalani@...omium.org>
To:     Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Benson Leung <bleung@...omium.org>, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org
Subject: Re: [PATCH 2/4] usb: typec: mux: intel_pmc_mux: Support for static
 SBU/HSL orientation

Hi Heikki,

Thanks for the patches.

On Thu, May 07, 2020 at 06:08:58PM +0300, Heikki Krogerus wrote:
> The SBU and HSL orientation may be fixed/static from the mux
> PoW. Apparently the retimer may take care of the orientation
> of these lines. Handling the static SBU (AUX) and HSL
> orientation with device properties.
> 
> If the SBU orientation is static, a device property
> "sbu-orintation" can be used. When the property exists, the
> driver always sets the SBU orientation according to the
> property value, and when it's not set, the driver uses the
> cable plug orientation with SBU.
> 
> And with static HSL orientation, "hsl-orientation" device
> property can be used in the same way.
> 
> Signed-off-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
> ---
>  drivers/usb/typec/mux/intel_pmc_mux.c | 42 +++++++++++++++++++++++----
>  1 file changed, 36 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c
> index f5c5e0aef66f..1aac218099f3 100644
> --- a/drivers/usb/typec/mux/intel_pmc_mux.c
> +++ b/drivers/usb/typec/mux/intel_pmc_mux.c
> @@ -91,6 +91,9 @@ struct pmc_usb_port {
>  
>  	u8 usb2_port;
>  	u8 usb3_port;
> +
> +	enum typec_orientation sbu_orientation;
> +	enum typec_orientation hsl_orientation;
>  };
>  
>  struct pmc_usb {
> @@ -99,6 +102,22 @@ struct pmc_usb {
>  	struct pmc_usb_port *port;
>  };
>  
> +static int sbu_orientation(struct pmc_usb_port *port)
> +{
> +	if (port->sbu_orientation)
> +		return port->sbu_orientation - 1;
> +
> +	return port->orientation - 1;
> +}
> +
> +static int hsl_orientation(struct pmc_usb_port *port)
> +{
> +	if (port->hsl_orientation)
> +		return port->hsl_orientation - 1;
> +
> +	return port->orientation - 1;
> +}
> +
>  static int pmc_usb_command(struct pmc_usb_port *port, u8 *msg, u32 len)
>  {
>  	u8 response[4];
> @@ -151,8 +170,9 @@ pmc_usb_mux_dp(struct pmc_usb_port *port, struct typec_mux_state *state)
>  
>  	req.mode_data = (port->orientation - 1) << PMC_USB_ALTMODE_ORI_SHIFT;
>  	req.mode_data |= (port->role - 1) << PMC_USB_ALTMODE_UFP_SHIFT;
> -	req.mode_data |= (port->orientation - 1) << PMC_USB_ALTMODE_ORI_AUX_SHIFT;
> -	req.mode_data |= (port->orientation - 1) << PMC_USB_ALTMODE_ORI_HSL_SHIFT;
> +
> +	req.mode_data |= sbu_orientation(port) << PMC_USB_ALTMODE_ORI_AUX_SHIFT;

I'm curious to know what would happen when sbu-orientation == "normal".
That means |port->sbu_orientation| == 1.

It sounds like what should happen is the AUX_SHIFT orientation
setting should follow what |port->orientation| is, but here it
looks like it will always be set to |port->sbu_orientation - 1|, i.e 0,
even if port->orientation == TYPEC_ORIENTATION_REVERSE, i.e 2, meaning
it should be set to 1 ?

Apologies if I misunderstood the code...


Best regards,


> +	req.mode_data |= hsl_orientation(port) << PMC_USB_ALTMODE_ORI_HSL_SHIFT;
>  
>  	req.mode_data |= (state->mode - TYPEC_STATE_MODAL) <<
>  			 PMC_USB_ALTMODE_DP_MODE_SHIFT;
> @@ -173,8 +193,9 @@ pmc_usb_mux_tbt(struct pmc_usb_port *port, struct typec_mux_state *state)
>  
>  	req.mode_data = (port->orientation - 1) << PMC_USB_ALTMODE_ORI_SHIFT;
>  	req.mode_data |= (port->role - 1) << PMC_USB_ALTMODE_UFP_SHIFT;
> -	req.mode_data |= (port->orientation - 1) << PMC_USB_ALTMODE_ORI_AUX_SHIFT;
> -	req.mode_data |= (port->orientation - 1) << PMC_USB_ALTMODE_ORI_HSL_SHIFT;
> +
> +	req.mode_data |= sbu_orientation(port) << PMC_USB_ALTMODE_ORI_AUX_SHIFT;
> +	req.mode_data |= hsl_orientation(port) << PMC_USB_ALTMODE_ORI_HSL_SHIFT;
>  
>  	if (TBT_ADAPTER(data->device_mode) == TBT_ADAPTER_TBT3)
>  		req.mode_data |= PMC_USB_ALTMODE_TBT_TYPE;
> @@ -211,8 +232,8 @@ static int pmc_usb_connect(struct pmc_usb_port *port)
>  	msg[0] |= port->usb3_port << PMC_USB_MSG_USB3_PORT_SHIFT;
>  
>  	msg[1] = port->usb2_port << PMC_USB_MSG_USB2_PORT_SHIFT;
> -	msg[1] |= (port->orientation - 1) << PMC_USB_MSG_ORI_HSL_SHIFT;
> -	msg[1] |= (port->orientation - 1) << PMC_USB_MSG_ORI_AUX_SHIFT;
> +	msg[1] |= hsl_orientation(port) << PMC_USB_MSG_ORI_HSL_SHIFT;
> +	msg[1] |= sbu_orientation(port) << PMC_USB_MSG_ORI_AUX_SHIFT;
>  
>  	return pmc_usb_command(port, msg, sizeof(msg));
>  }
> @@ -296,6 +317,7 @@ static int pmc_usb_register_port(struct pmc_usb *pmc, int index,
>  	struct usb_role_switch_desc desc = { };
>  	struct typec_switch_desc sw_desc = { };
>  	struct typec_mux_desc mux_desc = { };
> +	const char *str;
>  	int ret;
>  
>  	ret = fwnode_property_read_u8(fwnode, "usb2-port", &port->usb2_port);
> @@ -306,6 +328,14 @@ static int pmc_usb_register_port(struct pmc_usb *pmc, int index,
>  	if (ret)
>  		return ret;
>  
> +	ret = fwnode_property_read_string(fwnode, "sbu-orientation", &str);
> +	if (!ret)
> +		port->sbu_orientation = typec_find_orientation(str);
> +
> +	ret = fwnode_property_read_string(fwnode, "hsl-orientation", &str);
> +	if (!ret)
> +		port->hsl_orientation = typec_find_orientation(str);
> +
>  	port->num = index;
>  	port->pmc = pmc;
>  
> -- 
> 2.26.2
>