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

[Guenter Roeck <linux@xxxxxxxxxxxx>]

On 2/5/24 08:54, Marco Felsch wrote:
> Hi David,
>
> On 24-02-05, Dr. David Alan Gilbert wrote:
> > * Marco Felsch (m.felsch@xxxxxxxxxxxxxx) 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@xxxxxxxxxxxxxx>
> > > ---
> > >   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;
>
> You need to add it if there is code in between. Since there is no code,
> just this comment, it shouldn't be necessary.

Still, I think it would be desirable here to clarify that this
is not a lost return but intentionally sets
TCPC_CONFIG_STD_OUTPUT_ORIENTATION_NORMAL.

Guenter

> Regards,
>    Marco
>
> > 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   |_______/