diff options
| -rw-r--r-- | drivers/spi/spi-tegra210-quad.c | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c index e7bee8d5fb0b..2f806f4b2c34 100644 --- a/drivers/spi/spi-tegra210-quad.c +++ b/drivers/spi/spi-tegra210-quad.c @@ -117,6 +117,7 @@ #define QSPI_MISC_REG 0x194 #define QSPI_NUM_DUMMY_CYCLE(x) (((x) & 0xff) << 0) +#define QSPI_DUMMY_CYCLES_MAX 0xff #define DATA_DIR_TX BIT(0) #define DATA_DIR_RX BIT(1) @@ -170,6 +171,7 @@ struct tegra_qspi { u32 def_command2_reg; u32 spi_cs_timing1; u32 spi_cs_timing2; + u8 dummy_cycles; struct completion xfer_completion; struct spi_transfer *curr_xfer; @@ -856,6 +858,8 @@ static int tegra_qspi_start_transfer_one(struct spi_device *spi, tqspi->command1_reg = command1; + tegra_qspi_writel(tqspi, QSPI_NUM_DUMMY_CYCLE(tqspi->dummy_cycles), QSPI_MISC_REG); + ret = tegra_qspi_flush_fifos(tqspi, false); if (ret < 0) return ret; @@ -974,7 +978,7 @@ static int tegra_qspi_transfer_one_message(struct spi_master *master, struct spi { struct tegra_qspi *tqspi = spi_master_get_devdata(master); struct spi_device *spi = msg->spi; - struct spi_transfer *xfer; + struct spi_transfer *transfer; bool is_first_msg = true; int ret; @@ -983,9 +987,33 @@ static int tegra_qspi_transfer_one_message(struct spi_master *master, struct spi tqspi->tx_status = 0; tqspi->rx_status = 0; - list_for_each_entry(xfer, &msg->transfers, transfer_list) { + list_for_each_entry(transfer, &msg->transfers, transfer_list) { + struct spi_transfer *xfer = transfer; + u8 dummy_bytes = 0; u32 cmd1; + tqspi->dummy_cycles = 0; + /* + * Tegra QSPI hardware supports dummy bytes transfer after actual transfer + * bytes based on programmed dummy clock cycles in the QSPI_MISC register. + * So, check if the next transfer is dummy data transfer and program dummy + * clock cycles along with the current transfer and skip next transfer. + */ + if (!list_is_last(&xfer->transfer_list, &msg->transfers)) { + struct spi_transfer *next_xfer; + + next_xfer = list_next_entry(xfer, transfer_list); + if (next_xfer->dummy_data) { + u32 dummy_cycles = next_xfer->len * 8 / next_xfer->tx_nbits; + + if (dummy_cycles <= QSPI_DUMMY_CYCLES_MAX) { + tqspi->dummy_cycles = dummy_cycles; + dummy_bytes = next_xfer->len; + transfer = next_xfer; + } + } + } + reinit_completion(&tqspi->xfer_completion); cmd1 = tegra_qspi_setup_transfer_one(spi, xfer, is_first_msg); @@ -1016,7 +1044,7 @@ static int tegra_qspi_transfer_one_message(struct spi_master *master, struct spi goto complete_xfer; } - msg->actual_length += xfer->len; + msg->actual_length += xfer->len + dummy_bytes; complete_xfer: if (ret < 0) { |