[PATCH] mtd: spi-nor: cadence-quadspi: add reset control

From: Dinh Nguyen
Date: Mon Apr 08 2019 - 12:50:58 EST


Get the reset control for the QSPI controller and bring it out of reset.

Suggested-by: Tien-Fong Chee <tien.fong.chee@xxxxxxxxx>
Signed-off-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
---
drivers/mtd/spi-nor/cadence-quadspi.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 792628750eec..710a853f9d13 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -34,6 +34,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include <linux/sched.h>
#include <linux/spi/spi.h>
#include <linux/timer.h>
@@ -1336,6 +1337,7 @@ static int cqspi_probe(struct platform_device *pdev)
struct cqspi_st *cqspi;
struct resource *res;
struct resource *res_ahb;
+ struct reset_control *rstc;
const struct cqspi_driver_platdata *ddata;
int ret;
int irq;
@@ -1362,6 +1364,14 @@ static int cqspi_probe(struct platform_device *pdev)
return PTR_ERR(cqspi->clk);
}

+ /* Obtain QSPI reset control */
+ rstc = devm_reset_control_get_exclusive(dev, NULL);
+ if (!IS_ERR(rstc)) {
+ reset_control_assert(rstc);
+ udelay(1);
+ reset_control_deassert(rstc);
+ }
+
/* Obtain and remap controller address. */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
cqspi->iobase = devm_ioremap_resource(dev, res);
--
2.20.0