On Mon, Aug 31, 2020 at 07:59:15PM -0700, Badhri Jagan Sridharan wrote: > 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. > > Signed-off-by: Badhri Jagan Sridharan <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]> > --- > Changes since v1: > - Refactored the code to check for TX_BUF_BYTE_x_hidden as suggested by > Heikki. > - Not formatting the tcpci_pd_transmit to follow the 100 character/line > limit as suggested by Heikki. (Should be a separate change). > - Changing patch version to v6 to fix version number confusion. > --- > 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 bd80e03b2b6f..7d36d5e2d3f7 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 fd26ca35814c..cf9d8b63adcb 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); > -- > 2.28.0.402.g5ffc5be6b7-goog -- heikki
