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mtd: spi-nor: cadence-quadspi: add reset control

PATCH Superseded Dinh Nguyen 2 participants 2 messages Apr 8, 2019 – Apr 9, 2019

Subsystems (2)
Memory technology devices (MTD) SPI NOR

v1 of 2 Superseded Latest is v2 →

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Dinh Nguyen

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#0 lore raw

PATCH 1/1 mtd: spi-nor: cadence-quadspi: add reset control

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

Suggested-by Tien-Fong Chee <[email protected]>
Signed-off-by Dinh Nguyen <[email protected]>
---
 drivers/mtd/spi-nor/cadence-quadspi.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
drivers/mtd/spi-nor/cadence-quadspi.c +10 -0
index 792628750eec..710a853f9d13 100644
@@ -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);
Signature · 1 line
2.20.0
maintainer
#1 lore raw
Quoted 30 lines · Dinh Nguyen

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

Suggested-by Tien-Fong Chee <[email protected]>
Signed-off-by Dinh Nguyen <[email protected]>
---
 drivers/mtd/spi-nor/cadence-quadspi.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
drivers/mtd/spi-nor/cadence-quadspi.c +2 -0
index 792628750eec..710a853f9d13 100644
@@ -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);

drivers/mtd/spi-nor/cadence-quadspi.c static int cqspi_probe(struct platform_device *pdev) · line 1374

Quoted 10 lines
drivers/mtd/spi-nor/cadence-quadspi.c +8 -0
 	}
 
+	/* 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);
+	}
+

If reset is optional here why not use devm_reset_control_get_optional_exclusive() and handle error codes (like -EPROBE_DEFER) appropriately instead of ignoring them?

Quoted 4 lines
drivers/mtd/spi-nor/cadence-quadspi.c +0 -0
 	/* Obtain and remap controller address. */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	cqspi->iobase = devm_ioremap_resource(dev, res);
Signature · 2 lines
Regards
Vignesh