[PATCH 3/4] mmc: dw_mmc: Allow use of in-spec voltage range for vqmmc-supply

[Peng Fan]

On Sun, Jun 28, 2026 at 10:25:25AM +0000, Jonas Karlman wrote:
>The Rockchip RK3399 SoC SDMMC IO domain supports 1.8V and 3.0V mode, and
>the 3.0V mode is within SD Standards allowed 2.7V-3.6V range. However,
>the commit 0b75109b6aaf ("mmc: dw_mmc: return error for invalid voltage
>setting") help enforce strict 1.8V and 3.3V when setting vqmmc-supply
>making mmc_set_signal_voltage() now fail for MMC_SIGNAL_VOLTAGE_330 and
>leading to an improper switch to MMC_SIGNAL_VOLTAGE_180.
>
>Use regulator_set_value_clamp() to set an SD Standards voltage range,
>1.70V-1.95V and 2.7V-3.6V, I/O voltage instead of requiring an exact
>regulator value to closer match Linux and to fix use of 3.3V signal
>voltage on Rockchip RK3399 boards using MMC_IO_VOLTAGE=y.
>
>Fixes: 0b75109b6aaf ("mmc: dw_mmc: return error for invalid voltage setting")
>Signed-off-by: Jonas Karlman <jonas at kwiboo.se>

Reviewed-by: Peng Fan <peng.fan at nxp.com>