diff options
| -rw-r--r-- | drivers/mfd/cros_ec_spi.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c index faba03e2f1ef..16f228dc243f 100644 --- a/drivers/mfd/cros_ec_spi.c +++ b/drivers/mfd/cros_ec_spi.c @@ -71,12 +71,15 @@ * @spi: SPI device we are connected to * @last_transfer_ns: time that we last finished a transfer, or 0 if there * if no record + * @start_of_msg_delay: used to set the delay_usecs on the spi_transfer that + * is sent when we want to turn on CS at the start of a transaction. * @end_of_msg_delay: used to set the delay_usecs on the spi_transfer that * is sent when we want to turn off CS at the end of a transaction. */ struct cros_ec_spi { struct spi_device *spi; s64 last_transfer_ns; + unsigned int start_of_msg_delay; unsigned int end_of_msg_delay; }; @@ -366,7 +369,7 @@ static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev, struct ec_host_request *request; struct ec_host_response *response; struct cros_ec_spi *ec_spi = ec_dev->priv; - struct spi_transfer trans; + struct spi_transfer trans, trans_delay; struct spi_message msg; int i, len; u8 *ptr; @@ -393,13 +396,23 @@ static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev, goto exit; } + /* + * Leave a gap between CS assertion and clocking of data to allow the + * EC time to wakeup. + */ + spi_message_init(&msg); + if (ec_spi->start_of_msg_delay) { + memset(&trans_delay, 0, sizeof(trans_delay)); + trans_delay.delay_usecs = ec_spi->start_of_msg_delay; + spi_message_add_tail(&trans_delay, &msg); + } + /* Transmit phase - send our message */ memset(&trans, 0, sizeof(trans)); trans.tx_buf = ec_dev->dout; trans.rx_buf = rx_buf; trans.len = len; trans.cs_change = 1; - spi_message_init(&msg); spi_message_add_tail(&trans, &msg); ret = spi_sync(ec_spi->spi, &msg); @@ -602,6 +615,10 @@ static void cros_ec_spi_dt_probe(struct cros_ec_spi *ec_spi, struct device *dev) u32 val; int ret; + ret = of_property_read_u32(np, "google,cros-ec-spi-pre-delay", &val); + if (!ret) + ec_spi->start_of_msg_delay = val; + ret = of_property_read_u32(np, "google,cros-ec-spi-msg-delay", &val); if (!ret) ec_spi->end_of_msg_delay = val; |