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authorEsben Haabendal <eha@deif.com>2018-06-20 09:34:34 +0200
committerMark Brown <broonie@kernel.org>2018-06-20 14:46:03 +0100
commit0a4ec2c158634afa208ceda970b2c83764a1d99c (patch)
treed40d146310dee59ba9538c7b111f35e9a5ff40d6 /drivers/spi
parent9e1dc9bd099363760afdd2316fc057f9ca38b559 (diff)
downloadlinux-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.c39
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) {