From 19b65476839ed9e292237888f74551aee4600c7f Mon Sep 17 00:00:00 2001 From: Badhri Jagan Sridharan Date: Mon, 31 Aug 2020 19:59:15 -0700 Subject: [PATCH] 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: Heikki Krogerus Signed-off-by: Badhri Jagan Sridharan Link: https://lore.kernel.org/r/20200901025927.3596190-3-badhri@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/tcpm/tcpci.c | 46 ++++++++++++++++++++++++++-------- drivers/usb/typec/tcpm/tcpci.h | 8 ++++++ 2 files changed, 43 insertions(+), 11 deletions(-) diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c index bd80e03b2b6f8..7d36d5e2d3f73 100644 --- a/drivers/usb/typec/tcpm/tcpci.c +++ b/drivers/usb/typec/tcpm/tcpci.c @@ -330,23 +330,47 @@ static int tcpci_pd_transmit(struct tcpc_dev *tcpc, int ret; cnt = msg ? pd_header_cnt(header) * 4 : 0; - ret = regmap_write(tcpci->regmap, TCPC_TX_BYTE_CNT, cnt + 2); - if (ret < 0) - return ret; + /** + * 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; - ret = tcpci_write16(tcpci, TCPC_TX_HDR, header); - if (ret < 0) - return ret; + /* 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) { - ret = regmap_raw_write(tcpci->regmap, TCPC_TX_DATA, - &msg->payload, cnt); + 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; + + ret = tcpci_write16(tcpci, TCPC_TX_HDR, header); + if (ret < 0) + return ret; + + if (cnt > 0) { + 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; diff --git a/drivers/usb/typec/tcpm/tcpci.h b/drivers/usb/typec/tcpm/tcpci.h index fd26ca35814c1..cf9d8b63adcbc 100644 --- a/drivers/usb/typec/tcpm/tcpci.h +++ b/drivers/usb/typec/tcpm/tcpci.h @@ -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); -- 2.30.2