spi: dw: introduce support of loopback mode
For testing purposes it's good to have a loopback mode enabled. The patch adds
necessary bits for that.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index e2f7c5c..7064cd0 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -591,6 +591,9 @@
| (spi->mode << SPI_MODE_OFFSET)
| (chip->tmode << SPI_TMOD_OFFSET);
+ if (spi->mode & SPI_LOOP)
+ chip->cr0 |= 1 << SPI_SRL_OFFSET;
+
if (gpio_is_valid(spi->cs_gpio)) {
ret = gpio_direction_output(spi->cs_gpio,
!(spi->mode & SPI_CS_HIGH));
@@ -652,7 +655,7 @@
goto err_free_master;
}
- master->mode_bits = SPI_CPOL | SPI_CPHA;
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
master->bus_num = dws->bus_num;
master->num_chipselect = dws->num_cs;