Re: [PATCH v3 03/18] dmaengine: dma-jz4780: Avoid hardcoding number of channels

From: Vinod
Date: Tue Jul 24 2018 - 09:23:10 EST


On 21-07-18, 13:06, Paul Cercueil wrote:

> +static const struct jz4780_dma_soc_data jz4780_dma_soc_data[] = {
> + [ID_JZ4780] = { .nb_channels = 32, },

why the array of structs?

> +};
> +
> +static const struct of_device_id jz4780_dma_dt_match[] = {
> + { .compatible = "ingenic,jz4780-dma", .data = (void *)ID_JZ4780 },

the data should be jz4780_dma_soc_data? as you would add more data
later.. and not the enum..

> - jzdma = devm_kzalloc(dev, sizeof(*jzdma), GFP_KERNEL);
> + version = (enum jz_version)of_id->data;
> + soc_data = &jz4780_dma_soc_data[version];

this can be simplified if we do:

soc_data = device_get_match_data(pdev);

with:

static const struct jz4780_dma_soc_data jz4780_dma_soc_data = {
.nb_channels = 32,
};

and
{ .compatible = "ingenic,jz4780-dma", .data = (void *)jz4780_dma_soc_data },

You add more parameters in future patches and store soc_data in driver
object and use as is..

> + jzdma = devm_kzalloc(dev, sizeof(*jzdma)
> + + sizeof(*jzdma->chan) * soc_data->nb_channels,
> + GFP_KERNEL);
> if (!jzdma)
> return -ENOMEM;
>
> + jzdma->soc_data = soc_data;
> + jzdma->version = version;

why do you need to store version, driver should handle values and not
versions..

--
~Vinod