Re: [PATCH 2/2] spi/s3c64xx: Implement runtime PM support

["Heiko Stübner" <heiko@sntech.de>]

Am Montag, 5. Dezember 2011, 17:50:13 schrieb Mark Brown:
> Enable and disable the clocks to the SPI controller using runtime PM. This
> serves the dual purpose of reducing power consumption a little and letting
> the core know when the device is idle.
> 
> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Heiko Stuebner <heiko@sntech.de

Kgene and/or Grant: could we move this forward, as I would like to profit from 
this change later on too :-)


Thanks
Heiko

> ---
>  drivers/spi/spi-s3c64xx.c |   39 +++++++++++++++++++++++++++++++++++++++
>  1 files changed, 39 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
> index fef1c90..9031783 100644
> --- a/drivers/spi/spi-s3c64xx.c
> +++ b/drivers/spi/spi-s3c64xx.c
> @@ -25,6 +25,7 @@
>  #include <linux/clk.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/spi/spi.h>
> 
>  #include <mach/dma.h>
> @@ -782,6 +783,8 @@ static void s3c64xx_spi_work(struct work_struct *work)
>  	while (!acquire_dma(sdd))
>  		msleep(10);
> 
> +	pm_runtime_get_sync(&sdd->pdev->dev);
> +
>  	spin_lock_irqsave(&sdd->lock, flags);
> 
>  	while (!list_empty(&sdd->queue)
> @@ -810,6 +813,8 @@ static void s3c64xx_spi_work(struct work_struct *work)
>  	/* Free DMA channels */
>  	sdd->ops->release(sdd->rx_dma.ch, &s3c64xx_spi_dma_client);
>  	sdd->ops->release(sdd->tx_dma.ch, &s3c64xx_spi_dma_client);
> +
> +	pm_runtime_put(&sdd->pdev->dev);
>  }
> 
>  static int s3c64xx_spi_transfer(struct spi_device *spi,
> @@ -892,6 +897,8 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
>  		goto setup_exit;
>  	}
> 
> +	pm_runtime_get_sync(&sdd->pdev->dev);
> +
>  	/* Check if we can provide the requested rate */
>  	if (!sci->clk_from_cmu) {
>  		u32 psr, speed;
> @@ -924,6 +931,8 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
>  			err = -EINVAL;
>  	}
> 
> +	pm_runtime_put(&sdd->pdev->dev);
> +
>  setup_exit:
> 
>  	/* setup() returns with device de-selected */
> @@ -1159,6 +1168,8 @@ static int __init s3c64xx_spi_probe(struct
> platform_device *pdev) mem_res->end, mem_res->start,
>  					sdd->rx_dma.dmach, sdd->tx_dma.dmach);
> 
> +	pm_runtime_enable(&pdev->dev);
> +
>  	return 0;
> 
>  err9:
> @@ -1192,6 +1203,8 @@ static int s3c64xx_spi_remove(struct platform_device
> *pdev) struct resource	*mem_res;
>  	unsigned long flags;
> 
> +	pm_runtime_disable(&pdev->dev);
> +
>  	spin_lock_irqsave(&sdd->lock, flags);
>  	sdd->state |= SUSPND;
>  	spin_unlock_irqrestore(&sdd->lock, flags);
> @@ -1272,8 +1285,34 @@ static int s3c64xx_spi_resume(struct device *dev)
>  }
>  #endif /* CONFIG_PM */
> 
> +#ifdef CONFIG_PM_RUNTIME
> +static int s3c64xx_spi_runtime_suspend(struct device *dev)
> +{
> +	struct spi_master *master = spi_master_get(dev_get_drvdata(dev));
> +	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
> +
> +	clk_disable(sdd->clk);
> +	clk_disable(sdd->src_clk);
> +
> +	return 0;
> +}
> +
> +static int s3c64xx_spi_runtime_resume(struct device *dev)
> +{
> +	struct spi_master *master = spi_master_get(dev_get_drvdata(dev));
> +	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
> +
> +	clk_enable(sdd->src_clk);
> +	clk_enable(sdd->clk);
> +
> +	return 0;
> +}
> +#endif /* CONFIG_PM_RUNTIME */
> +
>  static struct dev_pm_ops s3c64xx_spi_pm = {
>  	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
> +	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
> +			   s3c64xx_spi_runtime_resume, NULL)
>  };
> 
>  static struct platform_driver s3c64xx_spi_driver = {