[PATCH v5 3/9] mmc: sdhci-of-k1: add regulator and pinctrl voltage switching support

[Troy Mitchell]

On Mon, Mar 30, 2026 at 16:38:04 CST, Iker Pedrosa wrote:
> Add voltage switching infrastructure for UHS-I modes by integrating both
> regulator framework (for supply voltage control) and pinctrl state
> switching (for pin drive strength optimization).
> 
> - Add regulator supply parsing and voltage switching callback
> - Add optional pinctrl state switching between "default" (3.3V) and
>   "state_uhs" (1.8V) configurations
> - Enable coordinated voltage and pin configuration changes for UHS modes
> 
> This provides complete voltage switching support while maintaining
> backward compatibility when pinctrl states are not defined.
> 
> Tested-by: Anand Moon <linux.amoon at gmail.com>
> Tested-by: Trevor Gamblin <tgamblin at baylibre.com>
> Acked-by: Adrian Hunter <adrian.hunter at intel.com>
> Signed-off-by: Iker Pedrosa <ikerpedrosam at gmail.com>
Reviewed-by: Troy Mitchell <troy.mitchell at linux.dev>