summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-atmel.c
diff options
context:
space:
mode:
authorAlexandru Ardelean <alexandru.ardelean@analog.com>2019-09-26 13:51:35 +0300
committerMark Brown <broonie@kernel.org>2019-10-15 13:44:10 +0300
commit6c613f68aabf33385c01e949204ac5ed30887161 (patch)
tree7c1d71fe3b8d7f6c63453a873c952c5719934895 /drivers/spi/spi-atmel.c
parentec3fa72fa8404128771a095d5a56b738752ba9ff (diff)
downloadlinux-6c613f68aabf33385c01e949204ac5ed30887161.tar.xz
spi: core,atmel: convert `word_delay_usecs` -> `word_delay` for spi_device
This change does a conversion from the `word_delay_usecs` -> `word_delay` for the `spi_device` struct. This allows users to specify inter-word delays in other unit types (nano-seconds or clock cycles), depending on how users want. The Atmel SPI driver is the only current user of the `word_delay_usecs` field (from the `spi_device` struct). So, it needed a slight conversion to use the `word_delay` as an `spi_delay` struct. In SPI core, the only required mechanism is to update the `word_delay` information per `spi_transfer`. This requires a bit more logic than before, because it needs that both delays be converted to a common unit (nano-seconds) for comparison. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20190926105147.7839-8-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-atmel.c')
-rw-r--r--drivers/spi/spi-atmel.c26
1 files changed, 24 insertions, 2 deletions
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 3ed5e663da6f..1471b049f99a 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -1149,12 +1149,31 @@ atmel_spi_pdc_interrupt(int irq, void *dev_id)
return ret;
}
+static int atmel_word_delay_csr(struct spi_device *spi, struct atmel_spi *as)
+{
+ struct spi_delay *delay = &spi->word_delay;
+ u32 value = delay->value;
+
+ switch (delay->unit) {
+ case SPI_DELAY_UNIT_NSECS:
+ value /= 1000;
+ break;
+ case SPI_DELAY_UNIT_USECS:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return (as->spi_clk / 1000000 * value) >> 5;
+}
+
static int atmel_spi_setup(struct spi_device *spi)
{
struct atmel_spi *as;
struct atmel_spi_device *asd;
u32 csr;
unsigned int bits = spi->bits_per_word;
+ int word_delay_csr;
as = spi_master_get_devdata(spi->master);
@@ -1178,11 +1197,14 @@ static int atmel_spi_setup(struct spi_device *spi)
*/
csr |= SPI_BF(DLYBS, 0);
+ word_delay_csr = atmel_word_delay_csr(spi, as);
+ if (word_delay_csr < 0)
+ return word_delay_csr;
+
/* DLYBCT adds delays between words. This is useful for slow devices
* that need a bit of time to setup the next transfer.
*/
- csr |= SPI_BF(DLYBCT,
- (as->spi_clk / 1000000 * spi->word_delay_usecs) >> 5);
+ csr |= SPI_BF(DLYBCT, word_delay_csr);
asd = spi->controller_state;
if (!asd) {