Re: [PATCH v3 2/3] mmc: usdhi6rol0: add support for UHS modes

[Lars Persson <lars.persson@axis.com>]

On 04/20/2016 04:53 PM, Lars Persson wrote:
> Add a start_signal_voltage_switch() operation to support enabling of
> UHS modes.
>
> Signed-off-by: Lars Persson <larper@axis.com>
> ---
>   drivers/mmc/host/usdhi6rol0.c | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
>
> diff --git a/drivers/mmc/host/usdhi6rol0.c b/drivers/mmc/host/usdhi6rol0.c
> index 807c06e..2585ea4 100644
> --- a/drivers/mmc/host/usdhi6rol0.c
> +++ b/drivers/mmc/host/usdhi6rol0.c
> @@ -1147,12 +1147,25 @@ static void usdhi6_enable_sdio_irq(struct mmc_host *mmc, int enable)
>   	}
>   }
>
> +static int usdhi6_sig_volt_switch(struct mmc_host *mmc, struct mmc_ios *ios)
> +{
> +	int ret;
> +

To support boards without regulator we need to put a 
IS_ERR_OR_NULL(mmc->supply.vqmmc) check here and bail out with return 0. 
Missing vqmmc is OK according to our binding document, but treated as an 
error by mmc_regulator_set_vqmmc().


> +	ret = mmc_regulator_set_vqmmc(mmc, ios);
> +
> +	if (ret < 0)
> +		dev_warn(mmc_dev(mmc), "Voltage switch failed: %d\n", ret);
> +
> +	return ret;
> +}
> +
>   static struct mmc_host_ops usdhi6_ops = {
>   	.request	= usdhi6_request,
>   	.set_ios	= usdhi6_set_ios,
>   	.get_cd		= usdhi6_get_cd,
>   	.get_ro		= usdhi6_get_ro,
>   	.enable_sdio_irq = usdhi6_enable_sdio_irq,
> +	.start_signal_voltage_switch = usdhi6_sig_volt_switch,
>   };
>
>   /*			State machine handlers				*/
>