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authorMark Brown <broonie@kernel.org>2024-05-29 11:07:55 +0100
committerMark Brown <broonie@kernel.org>2024-05-29 11:07:55 +0100
commitab0b5a99d371da201e65640a94d68c5322d9d6bd (patch)
tree16a6bc45f410f9e1750cb2fd6f3d0efe0200441f /drivers/spi
parent060bbd65dd4b4bcd519f6c470ec71fc58f9a6190 (diff)
parent837e53f766fe9423fcb4e0eacbb3b7ff0e33103c (diff)
Add optional reset control for Cadence SPI
Merge series from Ji Sheng Teoh <jisheng.teoh@starfivetech.com>: The first patch adds optional reset control to support assertion and deassertion of reset signal to properly bring the SPI device into an operating condition. The second patch documents the optional reset control into dt-bindings.
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-cadence.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index e5140532071d..4eacf3f6e031 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 = dev_err_probe(&pdev->dev, PTR_ERR(xspi->rstc),
+ "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)) {