Commit 19b65476 authored by Badhri Jagan Sridharan's avatar Badhri Jagan Sridharan Committed by Greg Kroah-Hartman
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usb: typec: tcpci: Add support when hidden tx registers are inaccessible 



TCPCI spec forbids direct access of TX_BUF_BYTE_x register.
The existing version of tcpci driver assumes that those registers
are directly addressible. Add support for tcpci chips which do
not support direct access to TX_BUF_BYTE_x registers. TX_BUF_BYTE_x
can only be accessed by I2C_WRITE_BYTE_COUNT.

Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: default avatarBadhri Jagan Sridharan <badhri@google.com>
Link: https://lore.kernel.org/r/20200901025927.3596190-3-badhri@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 492c1dc9

drivers/usb/typec/tcpm/tcpci.c

+35 −11
Original line number Diff line number Diff line
@@ -330,6 +330,31 @@ static int tcpci_pd_transmit(struct tcpc_dev *tcpc, 
	int ret;



	cnt = msg ? pd_header_cnt(header) * 4 : 0;

	/**

	 * TCPCI spec forbids direct access of TCPC_TX_DATA.

	 * But, since some of the chipsets offer this capability,

	 * it's fair to support both.

	 */

	if (tcpci->data->TX_BUF_BYTE_x_hidden) {

		u8 buf[TCPC_TRANSMIT_BUFFER_MAX_LEN] = {0,};

		u8 pos = 0;



		/* Payload + header + TCPC_TX_BYTE_CNT */

		buf[pos++] = cnt + 2;



		if (msg)

			memcpy(&buf[pos], &msg->header, sizeof(msg->header));



		pos += sizeof(header);



		if (cnt > 0)

			memcpy(&buf[pos], msg->payload, cnt);



		pos += cnt;

		ret = regmap_raw_write(tcpci->regmap, TCPC_TX_BYTE_CNT, buf, pos);

		if (ret < 0)

			return ret;

	} else {

		ret = regmap_write(tcpci->regmap, TCPC_TX_BYTE_CNT, cnt + 2);

		if (ret < 0)

			return ret;
@@ -339,14 +364,13 @@ static int tcpci_pd_transmit(struct tcpc_dev *tcpc, 
			return ret;



		if (cnt > 0) {

		ret = regmap_raw_write(tcpci->regmap, TCPC_TX_DATA,

				       &msg->payload, cnt);

			ret = regmap_raw_write(tcpci->regmap, TCPC_TX_DATA, &msg->payload, cnt);

			if (ret < 0)

				return ret;

		}

	}



	reg = (PD_RETRY_COUNT << TCPC_TRANSMIT_RETRY_SHIFT) |

		(type << TCPC_TRANSMIT_TYPE_SHIFT);

	reg = (PD_RETRY_COUNT << TCPC_TRANSMIT_RETRY_SHIFT) | (type << TCPC_TRANSMIT_TYPE_SHIFT);

	ret = regmap_write(tcpci->regmap, TCPC_TRANSMIT, reg);

	if (ret < 0)

		return ret;

drivers/usb/typec/tcpm/tcpci.h

+8 −0
Original line number Diff line number Diff line
@@ -128,9 +128,17 @@ 
#define TCPC_VBUS_VOLTAGE_ALARM_HI_CFG		0x76

#define TCPC_VBUS_VOLTAGE_ALARM_LO_CFG		0x78



/* I2C_WRITE_BYTE_COUNT + 1 when TX_BUF_BYTE_x is only accessible I2C_WRITE_BYTE_COUNT */

#define TCPC_TRANSMIT_BUFFER_MAX_LEN		31



/*

 * @TX_BUF_BYTE_x_hidden

 *		optional; Set when TX_BUF_BYTE_x can only be accessed through I2C_WRITE_BYTE_COUNT.

 */

struct tcpci;

struct tcpci_data {

	struct regmap *regmap;

	unsigned char TX_BUF_BYTE_x_hidden:1;

	int (*init)(struct tcpci *tcpci, struct tcpci_data *data);

	int (*set_vconn)(struct tcpci *tcpci, struct tcpci_data *data,

			 bool enable);

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