[U-Boot] [PATCH 2/2] rockchip: mmc: handle deprecation of 'clock-freq-min-max'

[Jaehoon Chung]

On 04/25/2017 04:52 PM, Philipp Tomsich wrote:
> The 'clock-freq-min-max' property was deprecated in the upstream
> (i.e. Linux) DTS bindings in favor of the 'max-frequency' property.

It's difference wit Linux kernel. "clock-freq-min-max" was deprecated in Linux.
Linux kernel is supporting to find the best clock value in core.c.

There are defined the freqs[] = {400000, ...., 100000}
then it should be looped to find the value from 400K to 100K.

As i know, u-boot doesn't support this..
If you set to min value as 400K..doesn't check the other values..

Best Regards,
Jaehoon Chung

> 
> With the latest RK3399 DTSI does no longer include the deprecated
> property and the rockchip_dw_mmc driver requiring it to be present,
> the driver doesn't bind to the node in the RK3399 DTSI any longer
> (thus breaking access to the SD card on the RK3399-Q7 board).
> 
> To fix this, we implement a similar logic as in the Linux driver: if
> the deprecated property is present, we issue a warning (if DEBUG is
> enabled); if it is missing, we require 'max-frequency' to be set and
> use it to create a min/max value-pair.
> 
> See https://github.com/torvalds/linux/commit/b023030f10573de738bbe8df63d43acab64c9f7b
> for the deprecation/matching change in Linux.
> 
> Signed-off-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> ---
> 
>  drivers/mmc/rockchip_dw_mmc.c | 20 ++++++++++++++++++--
>  1 file changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/rockchip_dw_mmc.c b/drivers/mmc/rockchip_dw_mmc.c
> index c36eda0..432ae20 100644
> --- a/drivers/mmc/rockchip_dw_mmc.c
> +++ b/drivers/mmc/rockchip_dw_mmc.c
> @@ -76,9 +76,25 @@ static int rockchip_dwmmc_ofdata_to_platdata(struct udevice *dev)
>  		return -EINVAL;
>  	priv->fifo_mode = fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
>  					  "fifo-mode");
> +
> +	/*
> +	 * 'clock-freq-min-max' is deprecated
> +	 * (see https://github.com/torvalds/linux/commit/b023030f10573de738bbe8df63d43acab64c9f7b)
> +	 */
>  	if (fdtdec_get_int_array(gd->fdt_blob, dev_of_offset(dev),
> -				 "clock-freq-min-max", priv->minmax, 2))
> -		return -EINVAL;
> +				 "clock-freq-min-max", priv->minmax, 2)) {
> +		int val = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
> +					  "max-frequency", -EINVAL);
> +
> +		if (val < 0)
> +			return val;
> +
> +		priv->minmax[0] = 400000;  /* 400 kHz */
> +		priv->minmax[1] = val;
> +	} else {
> +		debug("%s: 'clock-freq-min-max' property was deprecated.\n",
> +		      __func__);
> +	}
>  #endif
>  	return 0;
>  }
>