Modern exynos SoCs can support self loopback mode via setting BIT(3) of
MODE_CFG register. Previous SoCs don't have the bit so we need to add
has_loopback field in the s3c64xx_spi_port_config. Exynos Auto v9 SoC
has the bit and it will define the field to "true".
When it is set, SPI_LOOP mode will be marked.
Signed-off-by: Chanho Park <chanho61.park@xxxxxxxxxxx>
---
drivers/spi/spi-s3c64xx.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index a62c7baadc8b..e17c74c0d7de 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -59,6 +59,7 @@
#define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD (1<<17)
#define S3C64XX_SPI_MODE_BUS_TSZ_WORD (2<<17)
#define S3C64XX_SPI_MODE_BUS_TSZ_MASK (3<<17)
+#define S3C64XX_SPI_MODE_SELF_LOOPBACK (1<<3)
#define S3C64XX_SPI_MODE_RXDMA_ON (1<<2)
#define S3C64XX_SPI_MODE_TXDMA_ON (1<<1)
#define S3C64XX_SPI_MODE_4BURST (1<<0)
@@ -135,6 +136,7 @@ struct s3c64xx_spi_dma_data {
* @clk_from_cmu: True, if the controller does not include a clock mux and
* prescaler unit.
* @clk_ioclk: True if clock is present on this device
+ * @has_loopback: True if loopback mode can be supported
*
* The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
* differ in some aspects such as the size of the fifo and spi bus clock
@@ -149,6 +151,7 @@ struct s3c64xx_spi_port_config {
bool high_speed;
bool clk_from_cmu;
bool clk_ioclk;
+ bool has_loopback;
};
/**
@@ -659,6 +662,9 @@ static int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
break;
}
+ if ((sdd->cur_mode & SPI_LOOP) && sdd->port_conf->has_loopback)
+ val |= S3C64XX_SPI_MODE_SELF_LOOPBACK;
+
writel(val, regs + S3C64XX_SPI_MODE_CFG);
if (sdd->port_conf->clk_from_cmu) {
@@ -1148,6 +1154,8 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
SPI_BPW_MASK(8);
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ if (sdd->port_conf->has_loopback)
+ master->mode_bits |= SPI_LOOP;
master->auto_runtime_pm = true;
if (!is_polling(sdd))
master->can_dma = s3c64xx_spi_can_dma;
--
2.36.1
