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spi: spi-fsl-dspi: Simplify transfer counter handling

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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>
This commit is contained in:
Esben Haabendal 2018-06-20 09:34:34 +02:00 committed by Mark Brown
parent 9e1dc9bd09
commit 0a4ec2c158
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 14 additions and 25 deletions
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39
drivers/spi/spi-fsl-dspi.c
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@ -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) {