Re: [PATCH v2 2/4] rtc: pcf85363: Add support for NXP pcf85263 rtc

[Geert Uytterhoeven]

Hi Biju,

On Thu, Nov 29, 2018 at 6:03 PM Biju Das <biju....@bp.renesas.com> wrote:
> Add support for NXP pcf85263 real-time clock. pcf85263 rtc is compatible
> with pcf85363,except that pcf85363 has additional 64 bytes of RAM.
>
> 1 byte of nvmem is supported and exposed in sysfs (# is the instance
> number,starting with 0): /sys/bus/nvmem/devices/pcf85x63-#/nvmem
>
> Signed-off-by: Biju Das <biju....@bp.renesas.com>
> ---
>  V1-->V2 Incorporated Alexandre and Geert's review comment.

Thanks for the update!

> --- a/drivers/rtc/rtc-pcf85363.c
> +++ b/drivers/rtc/rtc-pcf85363.c

> @@ -321,15 +344,25 @@ static int pcf85363_probe(struct i2c_client *client,
>                           const struct i2c_device_id *id)
>  {
>         struct pcf85363 *pcf85363;
> -       struct nvmem_config nvmem_cfg = {
> -               .name = "pcf85363-",
> -               .word_size = 1,
> -               .stride = 1,
> -               .size = NVRAM_SIZE,
> -               .reg_read = pcf85363_nvram_read,
> -               .reg_write = pcf85363_nvram_write,
> +       const struct regmap_config *regmap_config = &pcf_85363_regmap_config;
> +       struct nvmem_config nvmem_cfg[] = {

static?

Although the nvmem_config is copied, and thus static is not needed, I
guess using static will decrease kernel size.

> +               {
> +                       .name = "pcf85x63-",
> +                       .word_size = 1,
> +                       .stride = 1,
> +                       .size = 1,
> +                       .reg_read = pcf85x63_nvram_read,
> +                       .reg_write = pcf85x63_nvram_write,
> +               }, {
> +                       .name = "pcf85363-",
> +                       .word_size = 1,
> +                       .stride = 1,
> +                       .size = NVRAM_SIZE,
> +                       .reg_read = pcf85363_nvram_read,
> +                       .reg_write = pcf85363_nvram_write,
> +               },
>         };
> -       int ret;
> +       int ret, i, num_nvmem = 2;
>
>         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
>                 return -ENODEV;
> @@ -339,7 +372,13 @@ static int pcf85363_probe(struct i2c_client *client,
>         if (!pcf85363)
>                 return -ENOMEM;
>
> -       pcf85363->regmap = devm_regmap_init_i2c(client, &regmap_config);
> +       if (of_device_get_match_data(&client->dev) ==
> +                                       &pcf_85263_regmap_config) {
> +               regmap_config = &pcf_85263_regmap_config;
> +               num_nvmem = 1;

I think it's cleaner if you store the full config (regmap_config + num_nvmem)
in of_device_id.data, instead of just the regmap_config, using

    struct pcf85x63_config {
            struct regmap_config regmap;
            unsigned int num_nvram;
    };

    static const struct pcf85x63_config pcf85263_config = { ... };
    static const struct pcf85x63_config pcf85363_config = { ... };

    static const struct of_device_id dev_ids[] = {
            { .compatible = "nxp,pcf85263", .data = &pcf_85263_config },
            { .compatible = "nxp,pcf85363", .data = &pcf_85363_config },
            { /* sentinel */ }
    };

Then you can just do

        struct pcf85x63_config *config = &pcf85363_config; /* default
for non-DT */
        void *data = of_device_get_match_data(&client->dev);
        if (data)
                config = data;

> +       }
> +
> +       pcf85363->regmap = devm_regmap_init_i2c(client, regmap_config);
>         if (IS_ERR(pcf85363->regmap)) {
>                 dev_err(&client->dev, "regmap allocation failed\n");
>                 return PTR_ERR(pcf85363->regmap);


Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds