Add optional reset control support for spi-cadence to properly bring
the SPI device into an operating condition.
Signed-off-by: Eng Lee Teh <englee.teh@xxxxxxxxxxxxxxxx>
Signed-off-by: Ley Foon Tan <leyfoon.tan@xxxxxxxxxxxxxxxx>
Signed-off-by: Ji Sheng Teoh <jisheng.teoh@xxxxxxxxxxxxxxxx>
---
drivers/spi/spi-cadence.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index e5140532071d..11530a531673 100644
--- a/drivers/spi/spi-cadence.c
+++ b/drivers/spi/spi-cadence.c
@@ -18,6 +18,7 @@
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include <linux/spi/spi.h>
/* Name of this driver */
@@ -111,6 +112,7 @@
* @dev_busy: Device busy flag
* @is_decoded_cs: Flag for decoder property set or not
* @tx_fifo_depth: Depth of the TX FIFO
+ * @rstc: Optional reset control for SPI controller
*/
struct cdns_spi {
void __iomem *regs;
@@ -125,6 +127,7 @@ struct cdns_spi {
u8 dev_busy;
u32 is_decoded_cs;
unsigned int tx_fifo_depth;
+ struct reset_control *rstc;
};
/* Macros for the SPI controller read/write */
@@ -588,6 +591,16 @@ static int cdns_spi_probe(struct platform_device *pdev)
goto remove_ctlr;
}
+ xspi->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi");
+ if (IS_ERR(xspi->rstc)) {
+ ret = PTR_ERR(xspi->rstc);
+ dev_err(&pdev->dev, "Cannot get SPI reset.\n");
+ goto remove_ctlr;
+ }
+
+ reset_control_assert(xspi->rstc);
+ reset_control_deassert(xspi->rstc);
+
if (!spi_controller_is_target(ctlr)) {
xspi->ref_clk = devm_clk_get_enabled(&pdev->dev, "ref_clk");
if (IS_ERR(xspi->ref_clk)) {
--
2.43.2
