From 9e1dc9bd099363760afdd2316fc057f9ca38b559 Mon Sep 17 00:00:00 2001 From: Esben Haabendal Date: Wed, 20 Jun 2018 09:34:33 +0200 Subject: [PATCH] spi: spi-fsl-dspi: Fix per transfer cs_change handling MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit As of 92dc20d83adec565378254c0630e839ff5674e14, transfer->cs_change has been supported for non-last transfers, but not for last transfer. This change brings handling of cs_change in line with the specification in spi.h, implementing handling of transfer->cs_change for all transfers. The value for CMD FIFO is precalculated with transfer->cs_change field taken into account, allowing for CS de-activate between transfers and keeping CS activated after last transfer. Signed-off-by: Esben Haabendal Acked-by: Martin Hundebøll Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-dspi.c | 68 +++++++++++++++++++++++++++------------------- 1 file changed, 40 insertions(+), 28 deletions(-) diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index 3bf135b..c0c3b8b 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -84,11 +84,16 @@ #define SPI_RSER_TCFQE 0x80000000 #define SPI_PUSHR 0x34 -#define SPI_PUSHR_CONT (1 << 31) -#define SPI_PUSHR_CTAS(x) (((x) & 0x00000003) << 28) -#define SPI_PUSHR_EOQ (1 << 27) -#define SPI_PUSHR_CTCNT (1 << 26) -#define SPI_PUSHR_PCS(x) (((1 << x) & 0x0000003f) << 16) +#define SPI_PUSHR_CMD_CONT (1 << 15) +#define SPI_PUSHR_CONT (SPI_PUSHR_CMD_CONT << 16) +#define SPI_PUSHR_CMD_CTAS(x) (((x) & 0x0003) << 12) +#define SPI_PUSHR_CTAS(x) (SPI_PUSHR_CMD_CTAS(x) << 16) +#define SPI_PUSHR_CMD_EOQ (1 << 11) +#define SPI_PUSHR_EOQ (SPI_PUSHR_CMD_EOQ << 16) +#define SPI_PUSHR_CMD_CTCNT (1 << 10) +#define SPI_PUSHR_CTCNT (SPI_PUSHR_CMD_CTCNT << 16) +#define SPI_PUSHR_CMD_PCS(x) ((1 << x) & 0x003f) +#define SPI_PUSHR_PCS(x) (SPI_PUSHR_CMD_PCS(x) << 16) #define SPI_PUSHR_TXDATA(x) ((x) & 0x0000ffff) #define SPI_PUSHR_SLAVE 0x34 @@ -189,9 +194,8 @@ struct fsl_dspi { void *rx; void *rx_end; char dataflags; - u8 cs; u16 void_write_data; - u32 cs_change; + u16 tx_cmd; const struct fsl_dspi_devtype_data *devtype_data; wait_queue_head_t waitq; @@ -254,8 +258,6 @@ static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) for (i = 0; i < dma->curr_xfer_len; i++) { dspi->dma->tx_dma_buf[i] = dspi_data_to_pushr(dspi, tx_word); - if ((dspi->cs_change) && (!dspi->len)) - dspi->dma->tx_dma_buf[i] &= ~SPI_PUSHR_CONT; } dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx, @@ -534,21 +536,22 @@ static void ns_delay_scale(char *psc, char *sc, int delay_ns, static u32 dspi_data_to_pushr(struct fsl_dspi *dspi, int tx_word) { - u16 d16; + u16 data, cmd; if (dspi->tx) { - d16 = tx_word ? *(u16 *)dspi->tx : *(u8 *)dspi->tx; + data = tx_word ? *(u16 *)dspi->tx : *(u8 *)dspi->tx; dspi->tx += tx_word + 1; } else { - d16 = dspi->void_write_data; + data = dspi->void_write_data; } dspi->len -= tx_word + 1; - return SPI_PUSHR_TXDATA(d16) | - SPI_PUSHR_PCS(dspi->cs) | - SPI_PUSHR_CTAS(0) | - SPI_PUSHR_CONT; + cmd = dspi->tx_cmd; + if (dspi->len > 0) + cmd |= SPI_PUSHR_CMD_CONT; + + return (cmd << 16) | SPI_PUSHR_TXDATA(data); } static void dspi_data_from_popr(struct fsl_dspi *dspi, int rx_word) @@ -587,12 +590,9 @@ static int dspi_eoq_write(struct fsl_dspi *dspi) dspi_pushr = dspi_data_to_pushr(dspi, tx_word); - if (dspi->len == 0 || tx_count == DSPI_FIFO_SIZE - 1) { - /* last transfer in the transfer */ + if (dspi->len == 0 || tx_count == DSPI_FIFO_SIZE - 1) + /* request EOQ flag for last transfer in queue */ dspi_pushr |= SPI_PUSHR_EOQ; - if ((dspi->cs_change) && (!dspi->len)) - dspi_pushr &= ~SPI_PUSHR_CONT; - } regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr); @@ -635,9 +635,6 @@ static int dspi_tcfq_write(struct fsl_dspi *dspi) dspi_pushr = dspi_data_to_pushr(dspi, tx_word); - if ((dspi->cs_change) && (!dspi->len)) - dspi_pushr &= ~SPI_PUSHR_CONT; - regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr); return tx_word + 1; @@ -672,11 +669,26 @@ static int dspi_transfer_one_message(struct spi_master *master, dspi->cur_transfer = transfer; dspi->cur_msg = message; dspi->cur_chip = spi_get_ctldata(spi); - dspi->cs = spi->chip_select; - dspi->cs_change = 0; + /* Prepare command word for CMD FIFO */ + dspi->tx_cmd = SPI_PUSHR_CMD_CTAS(0) | + SPI_PUSHR_CMD_PCS(spi->chip_select); if (list_is_last(&dspi->cur_transfer->transfer_list, - &dspi->cur_msg->transfers) || transfer->cs_change) - dspi->cs_change = 1; + &dspi->cur_msg->transfers)) { + /* Leave PCS activated after last transfer when + * cs_change is set. + */ + if (transfer->cs_change) + dspi->tx_cmd |= SPI_PUSHR_CMD_CONT; + } else { + /* Keep PCS active between transfers in same message + * when cs_change is not set, and de-activate PCS + * between transfers in the same message when + * cs_change is set. + */ + if (!transfer->cs_change) + dspi->tx_cmd |= SPI_PUSHR_CMD_CONT; + } + dspi->void_write_data = dspi->cur_chip->void_write_data; dspi->dataflags = 0; -- 2.7.4