Subject: [PATCH 1/2] net: davinci_mdio: enable and disable clock

From: [email-masked] (Vaibhav Hiremath)
Date: Fri, 3 Aug 2012 10:46:49 +0530

On 8/3/2012 1:13 AM, Daniel Mack wrote:
> Make the driver control the device clocks. Appearantly, the Davinci
> platform probes this driver with the clock all powered up, but on OMAP,
> this isn't the case.
> 
> Signed-off-by: Daniel Mack <[email-masked]>
> ---
>  drivers/net/ethernet/ti/davinci_mdio.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
> index cd7ee20..b4b6015 100644
> --- a/drivers/net/ethernet/ti/davinci_mdio.c
> +++ b/drivers/net/ethernet/ti/davinci_mdio.c
> @@ -332,6 +332,8 @@ static int __devinit davinci_mdio_probe(struct platform_device *pdev)
>  		goto bail_out;
>  	}
>  
> +	clk_enable(data->clk);
> +
>  	dev_set_drvdata(dev, data);
>  	data->dev = dev;
>  	spin_lock_init(&data->lock);
> @@ -379,8 +381,11 @@ bail_out:
>  	if (data->bus)
>  		mdiobus_free(data->bus);
>  
> -	if (data->clk)
> +	if (data->clk) {
> +		clk_disable(data->clk);
>  		clk_put(data->clk);
> +	}
> +
>  	pm_runtime_put_sync(&pdev->dev);
>  	pm_runtime_disable(&pdev->dev);
>  
> @@ -397,8 +402,11 @@ static int __devexit davinci_mdio_remove(struct platform_device *pdev)
>  	if (data->bus)
>  		mdiobus_free(data->bus);
>  
> -	if (data->clk)
> +	if (data->clk) {
> +		clk_disable(data->clk);
>  		clk_put(data->clk);
> +	}
> +
>  	pm_runtime_put_sync(&pdev->dev);
>  	pm_runtime_disable(&pdev->dev);
>  
> @@ -427,6 +435,8 @@ static int davinci_mdio_suspend(struct device *dev)
>  	data->suspended = true;
>  	spin_unlock(&data->lock);
>  
> +	clk_disable(data->clk);
> +
>  	return 0;
>  }
>  
> @@ -435,6 +445,8 @@ static int davinci_mdio_resume(struct device *dev)
>  	struct davinci_mdio_data *data = dev_get_drvdata(dev);
>  	u32 ctrl;
>  
> +	clk_enable(data->clk);
> +

Danial,

I would request you to wait for this, its not that simple and straight.
And once you migrate to runtime PM you don't need clk_enable/disable,
this should get handled under runtime PM api's.

Also have you read my another email post -

http://comments.gmane.org/gmane.linux.ports.arm.omap/80796

Certainly, with respect to CPSW & MDIO, this patch is not enough and
requires further investigation. I have started looking at this and
hopefully will have some solution soon...

Thanks,
Vaibhav