Re: [PATCH 8/9] DMA: shdma: initial of common code

["Shevchenko, Andriy" <andriy.shevchenko@intel.com>]

On Mon, 2014-04-07 at 21:07 +0100, Ben Dooks wrote:
> Add support for building shdma internal data from the device tree to allow
> converting the driver to be device tree enabled.
> 
> It includes a helper for the of case to build the internal data used to
> select and filter out the DMA channels from the ID information in the
> device tree. Also updates the documentation for the DT case.


Few minor comments below.

> --- a/drivers/dma/sh/shdma-of.c
> +++ b/drivers/dma/sh/shdma-of.c


> @@ -40,6 +71,109 @@ static struct dma_chan *shdma_of_xlate(struct of_phandle_args *dma_spec,
>  	return chan;
>  }
>  
> +const struct sh_dmae_pdata *
> +sh_dma_probe_of(struct platform_device *pdev, const struct of_device_id *ofmatch)
> +{
> +	const struct device_node *np = pdev->dev.of_node;
> +	const struct sh_dmae_of_info *ofinf;
> +	struct device *dev = &pdev->dev;
> +	struct sh_dmae_pdata *pdata;
> +	struct sh_dmae_channel *chan;
> +	struct property *prop;
> +	u32 nr_chan;
> +	unsigned ch;
> +	int ret;
> +	int len;
> +
> +	if (!ofmatch)
> +		return NULL;
> +
> +	ofinf = ofmatch->data;
> +
> +	pdata = devm_kzalloc(dev, sizeof(struct sh_dmae_pdata), GFP_KERNEL);

sizeof(*pdata) ?

> +	if (!pdata) {
> +		dev_err(dev, "failed to make platform data\n");
> +		return NULL;
> +	}
> +
> +	*pdata = *ofinf->pdata_template;	/* copy in template first */
> +
> +	ret = of_property_read_u32(np, "dma-channels", &nr_chan);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to get number of channels\n");
> +		return NULL;
> +	}
> +
> +	chan = devm_kzalloc(dev, nr_chan * sizeof(struct sh_dmae_channel),
> +			    GFP_KERNEL);

devm_kcalloc()

> +	if (!chan) {
> +		dev_err(dev, "cannot allocate %d channels\n", nr_chan);
> +		return NULL;
> +	}
> +
> +	pdata->channel = chan;
> +	pdata->channel_num = nr_chan;
> +
> +	dev_dbg(dev, "%d dma channels allocated\n", nr_chan);
> +
> +	for (ch = 0; ch < nr_chan; ch++) {
> +		struct sh_dmae_channel *cp = chan + ch;
> +		u32 base = ofinf->channel_offset + ofinf->channel_stride * ch;
> +
> +		cp->offset = base + ofinf->offset;
> +		cp->dmars = base + ofinf->dmars;
> +		cp->chclr_bit = ch;
> +		cp->chclr_offset = ofinf->chclr_offset;
> +
> +		dev_dbg(dev, "ch %d: off %08x, dmars %08x, bit %d, off %d\n",
> +			ch, cp->offset, cp->dmars,
> +			cp->chclr_bit, cp->chclr_offset);
> +	}
> +
> +	/* look in current, or parent node for the slave mappings */
> +	prop = of_find_property(np, "renesas,slaves", &len);
> +	if (!prop)
> +		prop = of_find_property(np->parent, "renesas,slaves", &len);
> +
> +	if (prop) {
> +		struct sh_dmae_slave_config *slaves;
> +		int nr_slaves = len / (sizeof(u32) * 3);
> +		const __be32 *of_ptr;
> +		u32 of_idx;
> +
> +		slaves = devm_kzalloc(dev, sizeof(*slaves) * nr_slaves,
> +				      GFP_KERNEL);

devm_kcalloc()

> +		if (!slaves) {
> +			dev_err(dev, "cannot allocate %d slaves\n", nr_slaves);
> +			return NULL;
> +		}
> +
> +		pdata->slave = slaves;
> +		pdata->slave_num = nr_slaves;
> +		of_idx = 0;
> +		of_ptr = NULL;
> +
> +		dev_dbg(dev, "building %d slaves\n", nr_slaves);
> +
> +		for (; nr_slaves > 0; nr_slaves--, slaves++) {
> +			of_ptr= of_prop_next_u32(prop, of_ptr, &of_idx);
> +			slaves->mid_rid = be32_to_cpu(*of_ptr);
> +			slaves->slave_id = slaves->mid_rid;
> +
> +			of_ptr= of_prop_next_u32(prop, of_ptr, &of_idx);
> +			slaves->chcr = be32_to_cpu(*of_ptr);
> +
> +			dev_dbg(dev, "slave: id %02x, chcr %08x, addr %08x\n",
> +				slaves->mid_rid, slaves->chcr, slaves->addr);
> +		}
> +	} else {
> +		dev_warn(dev, "did not find any slave information\n");
> +	}
> +
> +	pdev->dev.platform_data = pdata;
> +	return pdata;
> +};



-- 
Andy Shevchenko <andriy.shevchenko@intel.com>
Intel Finland Oy
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