[PATCH] mtd: fsl-quadspi: Access multiple chips simultaneously
Han Xu
han.xu at freescale.com
Thu Jan 15 15:26:55 PST 2015
Add supports for simultaneous access to multiple chips. Need to lock
the mutex before any quad spi operations and unlock the mutex after
operations complete.
Signed-off-by: Han Xu <han.xu at freescale.com>
---
drivers/mtd/spi-nor/fsl-quadspi.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 39763b9..7964511 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -26,6 +26,7 @@
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/spi-nor.h>
+#include <linux/mutex.h>
/* The registers */
#define QUADSPI_MCR 0x00
@@ -227,6 +228,7 @@ struct fsl_qspi {
u32 nor_num;
u32 clk_rate;
unsigned int chip_base_addr; /* We may support two chips. */
+ struct mutex lock;
};
static inline int is_vybrid_qspi(struct fsl_qspi *q)
@@ -751,6 +753,8 @@ static int fsl_qspi_prep(struct spi_nor *nor, enum spi_nor_ops ops)
struct fsl_qspi *q = nor->priv;
int ret;
+ mutex_lock(&q->lock);
+
ret = clk_enable(q->clk_en);
if (ret)
return ret;
@@ -771,6 +775,7 @@ static void fsl_qspi_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
clk_disable(q->clk);
clk_disable(q->clk_en);
+ mutex_unlock(&q->lock);
}
static int fsl_qspi_probe(struct platform_device *pdev)
@@ -862,6 +867,8 @@ static int fsl_qspi_probe(struct platform_device *pdev)
if (of_get_property(np, "fsl,qspi-has-second-chip", NULL))
has_second_chip = true;
+ mutex_init(&q->lock);
+
/* iterate the subnodes. */
for_each_available_child_of_node(dev->of_node, np) {
char modalias[40];
--
1.7.8
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