[PATCH v4 3/5] mmc: davinci_mmc: add DT support

[Manjunathappa, Prakash]

Hi Sekhar,

On Wed, Feb 27, 2013 at 17:13:43, Nori, Sekhar wrote:
> On 2/15/2013 11:52 AM, Manjunathappa, Prakash wrote:
> > Adds device tree support for davinci_mmc. Also add binding documentation.
> > As of now in non-dma PIO mode and without GPIO card_detect/write_protect
> > option because of dependencies on EDMA and GPIO module DT support.
> > 
> > Signed-off-by: Manjunathappa, Prakash <prakash.pm at ti.com>
> > Reviewed-by: Mark Rutland <mark.rutland at arm.com>
> > Cc: linux-mmc at vger.kernel.org
> > Cc: linux-arm-kernel at lists.infradead.org
> > Cc: davinci-linux-open-source at linux.davincidsp.com
> > Cc: devicetree-discuss at lists.ozlabs.org
> > Cc: cjb at laptop.org
> > Cc: Sekhar Nori <nsekhar at ti.com>
> > Cc: mporter at ti.com
> 
> > diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
> > index 874dc60..6b08b9a 100644
> > --- a/drivers/mmc/host/davinci_mmc.c
> > +++ b/drivers/mmc/host/davinci_mmc.c
> > @@ -34,6 +34,8 @@
> >  #include <linux/dma-mapping.h>
> >  #include <linux/edma.h>
> >  #include <linux/mmc/mmc.h>
> > +#include <linux/of.h>
> > +#include <linux/of_device.h>
> >  
> >  #include <linux/platform_data/mmc-davinci.h>
> >  
> > @@ -1156,6 +1158,7 @@ static void __init init_mmcsd_host(struct mmc_davinci_host *host)
> >  
> >  	mmc_davinci_reset_ctrl(host, 0);
> >  }
> > +
> 
> Stray line addition.
> 

I will fix this.

> >  static struct platform_device_id davinci_mmc_devtype[] = {
> >  	{
> >  		.name	= "davinci-mmc-dm355",
> > @@ -1168,9 +1171,63 @@ static struct platform_device_id davinci_mmc_devtype[] = {
> >  };
> >  MODULE_DEVICE_TABLE(platform, davinci_mmc_devtype);
> >  
> > -static int __init davinci_mmcsd_probe(struct platform_device *pdev)
> > +static const struct of_device_id davinci_mmc_dt_ids[] = {
> > +	{
> > +		.compatible = "ti,davinci-mmc-dm355",
> > +		.data = &davinci_mmc_devtype[MMC_CTLR_VERSION_1],
> > +	},
> > +	{
> > +		.compatible = "ti,davinci-mmc-da830",
> > +		.data = &davinci_mmc_devtype[MMC_CTLR_VERSION_2],
> > +	},
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(of, davinci_mmc_dt_ids);
> > +
> > +static struct davinci_mmc_config
> > +	*mmc_parse_pdata(struct platform_device *pdev)
> >  {
> > +	struct device_node *np;
> >  	struct davinci_mmc_config *pdata = pdev->dev.platform_data;
> > +	const struct of_device_id *match =
> > +		of_match_device(of_match_ptr(davinci_mmc_dt_ids), &pdev->dev);
> > +	u32 data;
> > +
> > +	np = pdev->dev.of_node;
> > +	if (!np)
> > +		return pdata;
> > +
> > +	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> > +	if (!pdata) {
> > +		dev_err(&pdev->dev, "Failed to allocate memory for struct davinci_mmc_config\n");
> > +		goto nodata;
> 
> devm_kzalloc() returns NULL on error so you will end up returning
> success in this case.
> 

Returns NULL on failure, caller is checking on NULL for failures.

        pdata = mmc_parse_pdata(pdev);
        if (pdata == NULL) {
                dev_err(&pdev->dev, "Can not get platform data\n");
                return -ENOENT;
        }

> > +	}
> > +
> > +	if (match)
> > +		pdev->id_entry = match->data;
> > +
> > +	of_property_read_u32(np, "max-frequency", &pdata->max_freq);
> > +	if (!pdata->max_freq)
> > +		dev_info(&pdev->dev, "'max-frequency' property not specified, defaulting to 25MHz\n");
> 
> 
> of_property_read_u32() returns error on failure. pdata->max_freq is not
> guaranteed to be zero in case of error. See comments atop
> of_property_read_u32_array().
> 

As pdata is from kzalloc, max_freq will remain NULL in case of_property_read_u32_array fails.
It makes sense to check for return value, I agree to change this.

Thanks,
Prakash