Re: [PATCH 1/6] mmc: sdhci-pltfm: Add structure for host-specific data

["Richard Röjfors" <richard.rojfors@pelagicore.com>]

On 09/29/2010 10:07 PM, Wolfram Sang wrote:
> We need to carry some information per host, e.g. the clock. Add a
> structure for it and initialize it in the generic part. Also do not use
> the parent of the platform_device (if it is available), this breaks the
> clock-matching on ARM.

The reason it's there is for instance a case when the shdci device is exposed
from a MFD device which sits on top of PCI. Then the parent (PCI device)
is the device that is DMA capable. This patch will break such usage.

What is the purpose of this patch? You allocate space for an extra struct,
which you have a pointer pointing to, but you never use the pointer?

>
> Signed-off-by: Wolfram Sang<w.sang@pengutronix.de>
> Cc: Richard Röjfors<richard.rojfors.ext@mocean-labs.com>
> ---
>
> Changes since last version:
>
> * added types.h

I saw no types.h?

> * removed usage of pdev->dev.parent to ensure clk-matching
>    Please speak up if this has a use case I failed to see!
>
>   drivers/mmc/host/sdhci-pltfm.c |    8 ++++----
>   drivers/mmc/host/sdhci-pltfm.h |    7 +++++++
>   2 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c
> index e045e3c..095ca9d 100644
> --- a/drivers/mmc/host/sdhci-pltfm.c
> +++ b/drivers/mmc/host/sdhci-pltfm.c
> @@ -55,6 +55,7 @@ static int __devinit sdhci_pltfm_probe(struct platform_device *pdev)
>   	struct sdhci_pltfm_data *pdata = pdev->dev.platform_data;
>   	const struct platform_device_id *platid = platform_get_device_id(pdev);
>   	struct sdhci_host *host;
> +	struct sdhci_pltfm_host *pltfm_host;
>   	struct resource *iomem;
>   	int ret;
>
> @@ -71,16 +72,15 @@ static int __devinit sdhci_pltfm_probe(struct platform_device *pdev)
>   		dev_err(&pdev->dev, "Invalid iomem size. You may "
>   			"experience problems.\n");
>
> -	if (pdev->dev.parent)
> -		host = sdhci_alloc_host(pdev->dev.parent, 0);
> -	else
> -		host = sdhci_alloc_host(&pdev->dev, 0);
> +	host = sdhci_alloc_host(&pdev->dev, sizeof(*pltfm_host));
>
>   	if (IS_ERR(host)) {
>   		ret = PTR_ERR(host);
>   		goto err;
>   	}
>
> +	pltfm_host = sdhci_priv(host);
> +
>   	host->hw_name = "platform";
>   	if (pdata&&  pdata->ops)
>   		host->ops = pdata->ops;
> diff --git a/drivers/mmc/host/sdhci-pltfm.h b/drivers/mmc/host/sdhci-pltfm.h
> index 900f329..93a0319 100644
> --- a/drivers/mmc/host/sdhci-pltfm.h
> +++ b/drivers/mmc/host/sdhci-pltfm.h
> @@ -11,8 +11,15 @@
>   #ifndef _DRIVERS_MMC_SDHCI_PLTFM_H
>   #define _DRIVERS_MMC_SDHCI_PLTFM_H
>
> +#include<linux/clk.h>
> +#include<linux/types.h>
>   #include<linux/sdhci-pltfm.h>
>
> +struct sdhci_pltfm_host {
> +	struct clk *clk;
> +	u32 scratchpad; /* to handle quirks across io-accessor calls */
> +};
> +
>   extern struct sdhci_pltfm_data sdhci_cns3xxx_pdata;
>
>   #endif /* _DRIVERS_MMC_SDHCI_PLTFM_H */

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