[PATCH 06/17] spi/atmel_spi: add flag to controller data for lock operations

Shubhrajyoti Datta omaplinuxkernel at gmail.com
Thu Nov 15 04:36:17 EST 2012


On Mon, Nov 12, 2012 at 2:22 PM, Wenyou Yang <wenyou.yang at atmel.com> wrote:
> From: Nicolas Ferre <nicolas.ferre at atmel.com>
>
> Will allow to drop the lock during DMA operations.
>
> Signed-off-by: Nicolas Ferre <nicolas.ferre at atmel.com>
> Cc: grant.likely at secretlab.ca
> Cc: spi-devel-general at lists.sourceforge.net
> ---
>  drivers/spi/spi-atmel.c |   31 +++++++++++++++++++------------
>  1 file changed, 19 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
> index 76a1baf..37f54c3 100644
> --- a/drivers/spi/spi-atmel.c
> +++ b/drivers/spi/spi-atmel.c
> @@ -187,6 +187,7 @@
>   */
>  struct atmel_spi {
>         spinlock_t              lock;
> +       unsigned long           flags;
>
>         resource_size_t         phybase;
>         void __iomem            *regs;
> @@ -323,6 +324,16 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
>                 gpio_set_value(asd->npcs_pin, !active);
>  }
>
> +static void atmel_spi_lock(struct atmel_spi *as)
> +{
> +               spin_lock_irqsave(&as->lock, as->flags);
> +}
> +
> +static void atmel_spi_unlock(struct atmel_spi *as)
> +{
> +               spin_unlock_irqrestore(&as->lock, as->flags);
> +}

May be this can be called directly.

> +
>  static inline int atmel_spi_xfer_is_last(struct spi_message *msg,
>                                         struct spi_transfer *xfer)
>  {
> @@ -559,9 +570,9 @@ atmel_spi_msg_done(struct spi_master *master, struct atmel_spi *as,
>                 "xfer complete: %u bytes transferred\n",
>                 msg->actual_length);
>
> -       spin_unlock(&as->lock);
> +       atmel_spi_unlock(as);
>         msg->complete(msg->context);
> -       spin_lock(&as->lock);
> +       atmel_spi_lock(as);
>
>         as->current_transfer = NULL;
>         as->next_transfer = NULL;
> @@ -788,13 +799,11 @@ static int atmel_spi_setup(struct spi_device *spi)
>                 spi->controller_state = asd;
>                 gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH));
>         } else {
> -               unsigned long           flags;
> -
> -               spin_lock_irqsave(&as->lock, flags);
> +               atmel_spi_lock(as);
>                 if (as->stay == spi)
>                         as->stay = NULL;
>                 cs_deactivate(as, spi);
> -               spin_unlock_irqrestore(&as->lock, flags);
> +               atmel_spi_unlock(as);
>         }
>
>         asd->csr = csr;
> @@ -813,7 +822,6 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg)
>  {
>         struct atmel_spi        *as;
>         struct spi_transfer     *xfer;
> -       unsigned long           flags;
>         struct device           *controller = spi->master->dev.parent;
>         u8                      bits;
>         struct atmel_spi_device *asd;
> @@ -878,11 +886,11 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg)
>         msg->status = -EINPROGRESS;
>         msg->actual_length = 0;
>
> -       spin_lock_irqsave(&as->lock, flags);
> +       atmel_spi_lock(as);
>         list_add_tail(&msg->queue, &as->queue);
>         if (!as->current_transfer)
>                 atmel_spi_next_message(spi->master);
> -       spin_unlock_irqrestore(&as->lock, flags);
> +       atmel_spi_unlock(as);
>
>         return 0;
>  }
> @@ -892,17 +900,16 @@ static void atmel_spi_cleanup(struct spi_device *spi)
>         struct atmel_spi        *as = spi_master_get_devdata(spi->master);
>         struct atmel_spi_device *asd = spi->controller_state;
>         unsigned                gpio = (unsigned) spi->controller_data;
> -       unsigned long           flags;
>
>         if (!asd)
>                 return;
>
> -       spin_lock_irqsave(&as->lock, flags);
> +       atmel_spi_lock(as);
>         if (as->stay == spi) {
>                 as->stay = NULL;
>                 cs_deactivate(as, spi);
>         }
> -       spin_unlock_irqrestore(&as->lock, flags);
> +       atmel_spi_unlock(as);
>
>         spi->controller_state = NULL;
>         gpio_free(gpio);
> --
> 1.7.9.5
>
>
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