linux-kernel - Re: [PATCH 4/4] usb: typec: tcpci: add support to set connector orientation

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Message-ID: <ZcESKqRTsGNZMMX1@gallifrey>
Date: Mon, 5 Feb 2024 16:51:54 +0000
From: "Dr. David Alan Gilbert" <linux@...blig.org>
To: Marco Felsch <m.felsch@...gutronix.de>
Cc: gregkh@...uxfoundation.org, robh+dt@...nel.org,
	krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org,
	linux@...ck-us.net, heikki.krogerus@...ux.intel.com,
	linux-usb@...r.kernel.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org, kernel@...gutronix.de
Subject: Re: [PATCH 4/4] usb: typec: tcpci: add support to set connector
 orientation

* Marco Felsch (m.felsch@...gutronix.de) wrote:
> This add the support to set the optional connector orientation bit which
> is part of the optional CONFIG_STANDARD_OUTPUT register 0x18 [1]. This
> allows system designers to connect the tcpc orientation pin directly to
> the 2:1 ss-mux.
> 
> [1] https://www.usb.org/sites/default/files/documents/usb-port_controller_specification_rev2.0_v1.0_0.pdf
> 
> Signed-off-by: Marco Felsch <m.felsch@...gutronix.de>
> ---
>  drivers/usb/typec/tcpm/tcpci.c | 43 ++++++++++++++++++++++++++++++++++
>  include/linux/usb/tcpci.h      |  8 +++++++
>  2 files changed, 51 insertions(+)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index 7118551827f6..7ce9d4923bc7 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -67,6 +67,18 @@ static int tcpci_write16(struct tcpci *tcpci, unsigned int reg, u16 val)
>  	return regmap_raw_write(tcpci->regmap, reg, &val, sizeof(u16));
>  }
>  
> +static bool tcpci_check_std_output_cap(struct regmap *regmap, u8 mask)
> +{
> +	unsigned int reg;
> +	int ret;
> +
> +	ret = regmap_read(regmap, TCPC_STD_OUTPUT_CAP, &reg);
> +	if (ret < 0)
> +		return ret;
> +
> +	return (reg & mask) == mask;
> +}
> +
>  static int tcpci_set_cc(struct tcpc_dev *tcpc, enum typec_cc_status cc)
>  {
>  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> @@ -301,6 +313,27 @@ static int tcpci_set_polarity(struct tcpc_dev *tcpc,
>  			   TCPC_TCPC_CTRL_ORIENTATION : 0);
>  }
>  
> +static int tcpci_set_orientation(struct tcpc_dev *tcpc,
> +				 enum typec_orientation orientation)
> +{
> +	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> +	unsigned int reg;
> +
> +	switch (orientation) {
> +	case TYPEC_ORIENTATION_NONE:
> +		/* We can't put a single output into high impedance */

Is that intended to be a fallthrough? If so I guess it needs
marking as such with a
                fallthrough;

Dave

> +	case TYPEC_ORIENTATION_NORMAL:
> +		reg = TCPC_CONFIG_STD_OUTPUT_ORIENTATION_NORMAL;
> +		break;
> +	case TYPEC_ORIENTATION_REVERSE:
> +		reg = TCPC_CONFIG_STD_OUTPUT_ORIENTATION_FLIPPED;
> +		break;
> +	}
> +
> +	return regmap_update_bits(tcpci->regmap, TCPC_CONFIG_STD_OUTPUT,
> +				  TCPC_CONFIG_STD_OUTPUT_ORIENTATION_MASK, reg);
> +}
> +
>  static void tcpci_set_partner_usb_comm_capable(struct tcpc_dev *tcpc, bool capable)
>  {
>  	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
> @@ -808,6 +841,9 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
>  	if (tcpci->data->vbus_vsafe0v)
>  		tcpci->tcpc.is_vbus_vsafe0v = tcpci_is_vbus_vsafe0v;
>  
> +	if (tcpci->data->set_orientation)
> +		tcpci->tcpc.set_orientation = tcpci_set_orientation;
> +
>  	err = tcpci_parse_config(tcpci);
>  	if (err < 0)
>  		return ERR_PTR(err);
> @@ -851,6 +887,13 @@ static int tcpci_probe(struct i2c_client *client)
>  	if (err < 0)
>  		return err;
>  
> +	err = tcpci_check_std_output_cap(chip->data.regmap,
> +					 TCPC_STD_OUTPUT_CAP_ORIENTATION);
> +	if (err < 0)
> +		return err;
> +
> +	chip->data.set_orientation = err;
> +
>  	chip->tcpci = tcpci_register_port(&client->dev, &chip->data);
>  	if (IS_ERR(chip->tcpci))
>  		return PTR_ERR(chip->tcpci);
> diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
> index 467e8045e9f8..f2bfb4250366 100644
> --- a/include/linux/usb/tcpci.h
> +++ b/include/linux/usb/tcpci.h
> @@ -47,6 +47,9 @@
>  #define TCPC_SINK_FAST_ROLE_SWAP	BIT(0)
>  
>  #define TCPC_CONFIG_STD_OUTPUT		0x18
> +#define TCPC_CONFIG_STD_OUTPUT_ORIENTATION_MASK		BIT(0)
> +#define TCPC_CONFIG_STD_OUTPUT_ORIENTATION_NORMAL	0
> +#define TCPC_CONFIG_STD_OUTPUT_ORIENTATION_FLIPPED	1
>  
>  #define TCPC_TCPC_CTRL			0x19
>  #define TCPC_TCPC_CTRL_ORIENTATION	BIT(0)
> @@ -127,6 +130,7 @@
>  #define TCPC_DEV_CAP_2			0x26
>  #define TCPC_STD_INPUT_CAP		0x28
>  #define TCPC_STD_OUTPUT_CAP		0x29
> +#define TCPC_STD_OUTPUT_CAP_ORIENTATION	BIT(0)
>  
>  #define TCPC_MSG_HDR_INFO		0x2e
>  #define TCPC_MSG_HDR_INFO_DATA_ROLE	BIT(3)
> @@ -198,12 +202,16 @@ struct tcpci;
>   *		Chip level drivers are expected to check for contaminant and call
>   *		tcpm_clean_port when the port is clean to put the port back into
>   *		toggling state.
> + * @set_orientation:
> + *		Optional; Enable setting the connector orientation
> + *		CONFIG_STANDARD_OUTPUT (0x18) bit0.
>   */
>  struct tcpci_data {
>  	struct regmap *regmap;
>  	unsigned char TX_BUF_BYTE_x_hidden:1;
>  	unsigned char auto_discharge_disconnect:1;
>  	unsigned char vbus_vsafe0v:1;
> +	unsigned char set_orientation:1;
>  
>  	int (*init)(struct tcpci *tcpci, struct tcpci_data *data);
>  	int (*set_vconn)(struct tcpci *tcpci, struct tcpci_data *data,
> -- 
> 2.39.2
> 
> 
-- 
 -----Open up your eyes, open up your mind, open up your code -------   
/ Dr. David Alan Gilbert    |       Running GNU/Linux       | Happy  \ 
\        dave @ treblig.org |                               | In Hex /
 \ _________________________|_____ http://www.treblig.org   |_______/