[PATCH] mtd: fsl-quadspi: Access multiple chips simultaneously

[Huang Shijie]

On Fri, Jan 16, 2015 at 07:26:55AM +0800, Han Xu wrote:
> 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];
> -- 

Acked-by: Huang Shijie <shijie.huang at intel.com>