diff options
| author | Esben Haabendal <eha@deif.com> | 2018-06-20 09:34:34 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2018-06-20 14:46:03 +0100 |
| commit | 0a4ec2c158634afa208ceda970b2c83764a1d99c (patch) | |
| tree | d40d146310dee59ba9538c7b111f35e9a5ff40d6 /drivers/spi | |
| parent | 9e1dc9bd099363760afdd2316fc057f9ca38b559 (diff) | |
| download | linux-0a4ec2c158634afa208ceda970b2c83764a1d99c.tar.bz2 | |
spi: spi-fsl-dspi: Simplify transfer counter handling
Simplify driver by avoiding counter wrapping by clearing transfer counter
on first SPI transfer per interrupt instead of tracking what it was before.
Signed-off-by: Esben Haabendal <eha@deif.com>
Acked-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-fsl-dspi.c | 39 |
1 files changed, 14 insertions, 25 deletions
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index c0c3b8bf2781..2371b9978e65 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -119,8 +119,6 @@ #define SPI_CS_ASSERT 0x02 #define SPI_CS_DROP 0x04 -#define SPI_TCR_TCNT_MAX 0x10000 - #define DMA_COMPLETION_TIMEOUT msecs_to_jiffies(3000) struct chip_data { @@ -201,7 +199,6 @@ struct fsl_dspi { wait_queue_head_t waitq; u32 waitflags; - u32 spi_tcnt; struct fsl_dspi_dma *dma; }; @@ -594,6 +591,10 @@ static int dspi_eoq_write(struct fsl_dspi *dspi) /* request EOQ flag for last transfer in queue */ dspi_pushr |= SPI_PUSHR_EOQ; + /* Clear transfer counter on first transfer (in FIFO) */ + if (tx_count == 0) + dspi_pushr |= SPI_PUSHR_CTCNT; + regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr); tx_count++; @@ -635,6 +636,9 @@ static int dspi_tcfq_write(struct fsl_dspi *dspi) dspi_pushr = dspi_data_to_pushr(dspi, tx_word); + /* Clear transfer counter on each transfer */ + dspi_pushr |= SPI_PUSHR_CTCNT; + regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr); return tx_word + 1; @@ -658,10 +662,6 @@ static int dspi_transfer_one_message(struct spi_master *master, struct spi_transfer *transfer; int status = 0; enum dspi_trans_mode trans_mode; - u32 spi_tcr; - - regmap_read(dspi->regmap, SPI_TCR, &spi_tcr); - dspi->spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr); message->actual_length = 0; @@ -831,7 +831,7 @@ static irqreturn_t dspi_interrupt(int irq, void *dev_id) struct spi_message *msg = dspi->cur_msg; enum dspi_trans_mode trans_mode; u32 spi_sr, spi_tcr; - u32 spi_tcnt, tcnt_diff; + u16 spi_tcnt; int tx_word; regmap_read(dspi->regmap, SPI_SR, &spi_sr); @@ -841,26 +841,15 @@ static irqreturn_t dspi_interrupt(int irq, void *dev_id) if (spi_sr & (SPI_SR_EOQF | SPI_SR_TCFQF)) { tx_word = is_double_byte_mode(dspi); + /* Get transfer counter (in number of SPI transfers). It was + * reset to 0 when transfer(s) were started. + */ regmap_read(dspi->regmap, SPI_TCR, &spi_tcr); spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr); - /* - * The width of SPI Transfer Counter in SPI_TCR is 16bits, - * so the max couner is 65535. When the counter reach 65535, - * it will wrap around, counter reset to zero. - * spi_tcnt my be less than dspi->spi_tcnt, it means the - * counter already wrapped around. - * SPI Transfer Counter is a counter of transmitted frames. - * The size of frame maybe two bytes. - */ - tcnt_diff = ((spi_tcnt + SPI_TCR_TCNT_MAX) - dspi->spi_tcnt) - % SPI_TCR_TCNT_MAX; - tcnt_diff *= (tx_word + 1); - if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM) - tcnt_diff--; - - msg->actual_length += tcnt_diff; - dspi->spi_tcnt = spi_tcnt; + /* Update total number of bytes that were transferred */ + msg->actual_length += spi_tcnt * (tx_word + 1) - + (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM ? 1 : 0); trans_mode = dspi->devtype_data->trans_mode; switch (trans_mode) { |