mtd: fsl-quadspi: Access multiple chips simultaneously
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 <b45815@freescale.com>
[Brian: reworked err path in fsl_qspi_prep()]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 52a872f..4fe13dd 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
@@ -233,6 +234,7 @@
u32 clk_rate;
unsigned int chip_base_addr; /* We may support two chips. */
bool has_second_chip;
+ struct mutex lock;
};
static inline int is_vybrid_qspi(struct fsl_qspi *q)
@@ -761,18 +763,24 @@
struct fsl_qspi *q = nor->priv;
int ret;
+ mutex_lock(&q->lock);
ret = clk_enable(q->clk_en);
if (ret)
- return ret;
+ goto err_mutex;
ret = clk_enable(q->clk);
- if (ret) {
- clk_disable(q->clk_en);
- return ret;
- }
+ if (ret)
+ goto err_clk;
fsl_qspi_set_base_addr(q, nor);
return 0;
+
+err_clk:
+ clk_disable(q->clk_en);
+err_mutex:
+ mutex_unlock(&q->lock);
+
+ return ret;
}
static void fsl_qspi_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
@@ -781,6 +789,7 @@
clk_disable(q->clk);
clk_disable(q->clk_en);
+ mutex_unlock(&q->lock);
}
static int fsl_qspi_probe(struct platform_device *pdev)
@@ -864,6 +873,8 @@
if (of_get_property(np, "fsl,qspi-has-second-chip", NULL))
q->has_second_chip = true;
+ mutex_init(&q->lock);
+
/* iterate the subnodes. */
for_each_available_child_of_node(dev->of_node, np) {
char modalias[40];
@@ -892,24 +903,24 @@
ret = of_modalias_node(np, modalias, sizeof(modalias));
if (ret < 0)
- goto irq_failed;
+ goto mutex_failed;
ret = of_property_read_u32(np, "spi-max-frequency",
&q->clk_rate);
if (ret < 0)
- goto irq_failed;
+ goto mutex_failed;
/* set the chip address for READID */
fsl_qspi_set_base_addr(q, nor);
ret = spi_nor_scan(nor, modalias, SPI_NOR_QUAD);
if (ret)
- goto irq_failed;
+ goto mutex_failed;
ppdata.of_node = np;
ret = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
if (ret)
- goto irq_failed;
+ goto mutex_failed;
/* Set the correct NOR size now. */
if (q->nor_size == 0) {
@@ -950,6 +961,8 @@
i *= 2;
mtd_device_unregister(&q->mtd[i]);
}
+mutex_failed:
+ mutex_destroy(&q->lock);
irq_failed:
clk_disable_unprepare(q->clk);
clk_failed:
@@ -973,6 +986,7 @@
writel(QUADSPI_MCR_MDIS_MASK, q->iobase + QUADSPI_MCR);
writel(0x0, q->iobase + QUADSPI_RSER);
+ mutex_destroy(&q->lock);
clk_unprepare(q->clk);
clk_unprepare(q->clk_en);
return 0;