usb: typec: tcpci: add support to set connector orientation

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@pengutronix.de>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240701132133.3054394-1-m.felsch@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Marco Felsch

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 +313,28 @@ 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 */
+		fallthrough;
+	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);
@@ -830,6 +864,9 @@ 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);
@@ -873,6 +910,13 @@ 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);

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)
@@ -209,13 +213,17 @@ struct tcpci;
  *		swap following Discover Identity on SOP' occurs.
  *		Return true when the TCPM is allowed to request a Vconn swap
  *		after Discovery Identity on SOP.
+ * @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 cable_comm_capable: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,