[PATCH 0/2] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux

[PATCH 0/2] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux

[Josua Mayer]

Some Renesas SoC based boards mux SD and eMMC on a single sdio
controller, exposing user control by dip switch and software control by
gpio.

Purpose is to simplify development and provisioning by selecting boot
media at power-on, and again before starting linux.

Add binding and driver support for linking a (gpio) mux to renesas sdio
controller.

Signed-off-by: Josua Mayer <josua@solid-run.com>
---
Josua Mayer (2):
      dt-bindings: mmc: renesas,sdhi: Add mux-states property
      mmc: host: renesas_sdhi_core: support configuring an optional sdio mux

 .../devicetree/bindings/mmc/renesas,sdhi.yaml      | 14 +++++++++++
 drivers/mmc/host/Kconfig                           |  1 +
 drivers/mmc/host/renesas_sdhi.h                    |  1 +
 drivers/mmc/host/renesas_sdhi_core.c               | 27 +++++++++++++++++++---
 4 files changed, 40 insertions(+), 3 deletions(-)
---
base-commit: 3a8660878839faadb4f1a6dd72c3179c1df56787
change-id: 20251128-rz-sdio-mux-acc5137f1618

Best regards,
-- 
Josua Mayer <josua@solid-run.com>

[PATCH 1/2] dt-bindings: mmc: renesas,sdhi: Add mux-states property

[Josua Mayer]

Add mux controller support for when sdio lines are muxed between a host
and multiple cards.

There are several devices supporting a choice of eMMC or SD on a single
board by both dip switch and gpio, e.g. Renesas RZ/G2L SMARC SoM and
SolidRun RZ/G2L SoM.

In-tree dts for the Renesas boards currently rely on preprocessor macros
to hog gpios and define the card.

By adding mux-states property to sdio controller description, boards can
correctly describe the mux that already exists in hardware - and drivers
can coordinate between mux selection and probing for cards.

Signed-off-by: Josua Mayer <josua@solid-run.com>
---
 Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
index c754ea71f51f7..55635c60ad73a 100644
--- a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
+++ b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
@@ -106,6 +106,11 @@ properties:
   iommus:
     maxItems: 1
 
+  mux-states:
+    description:
+      mux controller node to route the SDIO signals from SoC to cards.
+    maxItems: 1
+
   power-domains:
     maxItems: 1
 
@@ -262,9 +267,17 @@ unevaluatedProperties: false
 examples:
   - |
     #include <dt-bindings/clock/r8a7790-cpg-mssr.h>
+    #include <dt-bindings/gpio/gpio.h>
     #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/pinctrl/rzg2l-pinctrl.h>
     #include <dt-bindings/power/r8a7790-sysc.h>
 
+    mux: mux-controller {
+            compatible = "gpio-mux";
+            #mux-state-cells = <1>;
+            mux-gpios = <&pinctrl RZG2L_GPIO(22, 1) GPIO_ACTIVE_LOW>;
+    };
+
     sdhi0: mmc@ee100000 {
         compatible = "renesas,sdhi-r8a7790", "renesas,rcar-gen2-sdhi";
         reg = <0xee100000 0x328>;
@@ -275,6 +288,7 @@ examples:
         max-frequency = <195000000>;
         power-domains = <&sysc R8A7790_PD_ALWAYS_ON>;
         resets = <&cpg 314>;
+        mux-states = <&mux 0>;
     };
 
     sdhi1: mmc@ee120000 {

-- 
2.51.0

[PATCH 2/2] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux

[Josua Mayer]

Some hardware designs route sdio signals through a mux to support
multiple devices on a single sdio controller.
In particular SolidRun RZ/G2L/G2LC/V2L System on Module use a mux for
switching between soldered eMMC and an optional microSD on a carrier
board, e.g. for development or provisioning.

SDIO is not well suited for runtime switching between different cards,
however boot-time selection is possible and useful in particular with dt
overlays.

Add support for an optional sdio mux defined in dt and select it during
probe.

Similar functionality already exists in other places, e.g. i2c-omap.

Signed-off-by: Josua Mayer <josua@solid-run.com>
---
 drivers/mmc/host/Kconfig             |  1 +
 drivers/mmc/host/renesas_sdhi.h      |  1 +
 drivers/mmc/host/renesas_sdhi_core.c | 27 ++++++++++++++++++++++++---
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 2c963cb6724b9..c01ab7d81a5af 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -707,6 +707,7 @@ config MMC_SDHI
 	depends on SUPERH || ARCH_RENESAS || COMPILE_TEST
 	depends on (RESET_CONTROLLER && REGULATOR) || !OF
 	select MMC_TMIO_CORE
+	select MULTIPLEXER
 	help
 	  This provides support for the SDHI SD/SDIO controller found in
 	  Renesas SuperH, ARM and ARM64 based SoCs
diff --git a/drivers/mmc/host/renesas_sdhi.h b/drivers/mmc/host/renesas_sdhi.h
index 084964cecf9d8..9508908d8179f 100644
--- a/drivers/mmc/host/renesas_sdhi.h
+++ b/drivers/mmc/host/renesas_sdhi.h
@@ -97,6 +97,7 @@ struct renesas_sdhi {
 	struct reset_control *rstc;
 	struct tmio_mmc_host *host;
 	struct regulator_dev *rdev;
+	struct mux_state *mux_state;
 };
 
 #define host_to_priv(host) \
diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index f56fa2cd208dd..c58f412ea2028 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -26,6 +26,7 @@
 #include <linux/mmc/mmc.h>
 #include <linux/mmc/slot-gpio.h>
 #include <linux/module.h>
+#include <linux/mux/consumer.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/pinctrl/pinctrl-state.h>
 #include <linux/platform_data/tmio.h>
@@ -1061,6 +1062,7 @@ int renesas_sdhi_probe(struct platform_device *pdev,
 	struct regulator_dev *rdev;
 	struct renesas_sdhi_dma *dma_priv;
 	struct device *dev = &pdev->dev;
+	struct device_node *node = pdev->dev.of_node;
 	struct tmio_mmc_host *host;
 	struct renesas_sdhi *priv;
 	int num_irqs, irq, ret, i;
@@ -1115,9 +1117,25 @@ int renesas_sdhi_probe(struct platform_device *pdev,
 						"state_uhs");
 	}
 
+	if (of_property_present(node, "mux-states")) {
+		priv->mux_state = devm_mux_state_get(&pdev->dev, NULL);
+		if (IS_ERR(priv->mux_state)) {
+			ret = PTR_ERR(priv->mux_state);
+			dev_dbg(&pdev->dev, "failed to get SDIO mux: %d\n", ret);
+			return ret;
+		}
+		ret = mux_state_select(priv->mux_state);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to select SDIO mux: %d\n", ret);
+			return ret;
+		}
+	}
+
 	host = tmio_mmc_host_alloc(pdev, mmc_data);
-	if (IS_ERR(host))
-		return PTR_ERR(host);
+	if (IS_ERR(host)) {
+		ret = PTR_ERR(host);
+		goto edselmux;
+	}
 
 	priv->host = host;
 
@@ -1200,7 +1218,7 @@ int renesas_sdhi_probe(struct platform_device *pdev,
 
 	ret = renesas_sdhi_clk_enable(host);
 	if (ret)
-		return ret;
+		goto edselmux;
 
 	rcfg.of_node = of_get_available_child_by_name(dev->of_node, "vqmmc-regulator");
 	if (rcfg.of_node) {
@@ -1304,6 +1322,9 @@ int renesas_sdhi_probe(struct platform_device *pdev,
 
 edisclk:
 	renesas_sdhi_clk_disable(host);
+edselmux:
+	if (priv->mux_state)
+		mux_state_deselect(priv->mux_state);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(renesas_sdhi_probe);

-- 
2.51.0

Re: [PATCH 1/2] dt-bindings: mmc: renesas,sdhi: Add mux-states property

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 2526 bytes --]

On Fri, Nov 28, 2025 at 05:15:38PM +0100, Josua Mayer wrote:
> Add mux controller support for when sdio lines are muxed between a host
> and multiple cards.
> 
> There are several devices supporting a choice of eMMC or SD on a single
> board by both dip switch and gpio, e.g. Renesas RZ/G2L SMARC SoM and
> SolidRun RZ/G2L SoM.
> 
> In-tree dts for the Renesas boards currently rely on preprocessor macros
> to hog gpios and define the card.
> 
> By adding mux-states property to sdio controller description, boards can
> correctly describe the mux that already exists in hardware - and drivers
> can coordinate between mux selection and probing for cards.
> 
> Signed-off-by: Josua Mayer <josua@solid-run.com>
> ---
>  Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> index c754ea71f51f7..55635c60ad73a 100644
> --- a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> +++ b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> @@ -106,6 +106,11 @@ properties:
>    iommus:
>      maxItems: 1
>  
> +  mux-states:
> +    description:
> +      mux controller node to route the SDIO signals from SoC to cards.
> +    maxItems: 1
> +
>    power-domains:
>      maxItems: 1
>  
> @@ -262,9 +267,17 @@ unevaluatedProperties: false
>  examples:
>    - |
>      #include <dt-bindings/clock/r8a7790-cpg-mssr.h>
> +    #include <dt-bindings/gpio/gpio.h>
>      #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/pinctrl/rzg2l-pinctrl.h>
>      #include <dt-bindings/power/r8a7790-sysc.h>
>  
> +    mux: mux-controller {
> +            compatible = "gpio-mux";
> +            #mux-state-cells = <1>;
> +            mux-gpios = <&pinctrl RZG2L_GPIO(22, 1) GPIO_ACTIVE_LOW>;
> +    };

This node should be removed, the tooling will provide a fake phandle to
satisfy your mux-states property.

pw-bot: changes-requested

> +
>      sdhi0: mmc@ee100000 {
>          compatible = "renesas,sdhi-r8a7790", "renesas,rcar-gen2-sdhi";
>          reg = <0xee100000 0x328>;
> @@ -275,6 +288,7 @@ examples:
>          max-frequency = <195000000>;
>          power-domains = <&sysc R8A7790_PD_ALWAYS_ON>;
>          resets = <&cpg 314>;
> +        mux-states = <&mux 0>;
>      };
>  
>      sdhi1: mmc@ee120000 {
> 
> -- 
> 2.51.0
> 

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Re: [PATCH 1/2] dt-bindings: mmc: renesas,sdhi: Add mux-states property

[Krzysztof Kozlowski]

On 28/11/2025 17:15, Josua Mayer wrote:
> Add mux controller support for when sdio lines are muxed between a host
> and multiple cards.
> 
> There are several devices supporting a choice of eMMC or SD on a single
> board by both dip switch and gpio, e.g. Renesas RZ/G2L SMARC SoM and
> SolidRun RZ/G2L SoM.
> 
> In-tree dts for the Renesas boards currently rely on preprocessor macros
> to hog gpios and define the card.
> 
> By adding mux-states property to sdio controller description, boards can
> correctly describe the mux that already exists in hardware - and drivers
> can coordinate between mux selection and probing for cards.
> 
> Signed-off-by: Josua Mayer <josua@solid-run.com>
> ---
>  Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> index c754ea71f51f7..55635c60ad73a 100644
> --- a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> +++ b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> @@ -106,6 +106,11 @@ properties:
>    iommus:
>      maxItems: 1
>  
> +  mux-states:
> +    description:
> +      mux controller node to route the SDIO signals from SoC to cards.
> +    maxItems: 1
> +
>    power-domains:
>      maxItems: 1
>  
> @@ -262,9 +267,17 @@ unevaluatedProperties: false
>  examples:
>    - |
>      #include <dt-bindings/clock/r8a7790-cpg-mssr.h>
> +    #include <dt-bindings/gpio/gpio.h>
>      #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/pinctrl/rzg2l-pinctrl.h>
>      #include <dt-bindings/power/r8a7790-sysc.h>
>  
> +    mux: mux-controller {
> +            compatible = "gpio-mux";
> +            #mux-state-cells = <1>;
> +            mux-gpios = <&pinctrl RZG2L_GPIO(22, 1) GPIO_ACTIVE_LOW>;


Wrong indentation and not really relevant here, so just drop.

Best regards,
Krzysztof

Re: [PATCH 1/2] dt-bindings: mmc: renesas,sdhi: Add mux-states property

[Josua Mayer]

Am 28.11.25 um 19:49 schrieb Conor Dooley:
> On Fri, Nov 28, 2025 at 05:15:38PM +0100, Josua Mayer wrote:
>> Add mux controller support for when sdio lines are muxed between a host
>> and multiple cards.
>>
>> There are several devices supporting a choice of eMMC or SD on a single
>> board by both dip switch and gpio, e.g. Renesas RZ/G2L SMARC SoM and
>> SolidRun RZ/G2L SoM.
>>
>> In-tree dts for the Renesas boards currently rely on preprocessor macros
>> to hog gpios and define the card.
>>
>> By adding mux-states property to sdio controller description, boards can
>> correctly describe the mux that already exists in hardware - and drivers
>> can coordinate between mux selection and probing for cards.
>>
>> Signed-off-by: Josua Mayer <josua@solid-run.com>
>> ---
>>  Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml | 14 ++++++++++++++
>>  1 file changed, 14 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
>> index c754ea71f51f7..55635c60ad73a 100644
>> --- a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
>> +++ b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
>> @@ -106,6 +106,11 @@ properties:
>>    iommus:
>>      maxItems: 1
>>  
>> +  mux-states:
>> +    description:
>> +      mux controller node to route the SDIO signals from SoC to cards.
>> +    maxItems: 1
>> +
>>    power-domains:
>>      maxItems: 1
>>  
>> @@ -262,9 +267,17 @@ unevaluatedProperties: false
>>  examples:
>>    - |
>>      #include <dt-bindings/clock/r8a7790-cpg-mssr.h>
>> +    #include <dt-bindings/gpio/gpio.h>
>>      #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +    #include <dt-bindings/pinctrl/rzg2l-pinctrl.h>
>>      #include <dt-bindings/power/r8a7790-sysc.h>
>>  
>> +    mux: mux-controller {
>> +            compatible = "gpio-mux";
>> +            #mux-state-cells = <1>;
>> +            mux-gpios = <&pinctrl RZG2L_GPIO(22, 1) GPIO_ACTIVE_LOW>;
>> +    };
> This node should be removed, the tooling will provide a fake phandle to
> satisfy your mux-states property.
Will drop, thanks!
>
> pw-bot: changes-requested
>
>> +
>>      sdhi0: mmc@ee100000 {
>>          compatible = "renesas,sdhi-r8a7790", "renesas,rcar-gen2-sdhi";
>>          reg = <0xee100000 0x328>;
>> @@ -275,6 +288,7 @@ examples:
>>          max-frequency = <195000000>;
>>          power-domains = <&sysc R8A7790_PD_ALWAYS_ON>;
>>          resets = <&cpg 314>;
>> +        mux-states = <&mux 0>;
>>      };
>>  
>>      sdhi1: mmc@ee120000 {
>>
>> -- 
>> 2.51.0
>>

Re: [PATCH 1/2] dt-bindings: mmc: renesas,sdhi: Add mux-states property

[Josua Mayer]

Am 30.11.25 um 09:22 schrieb Krzysztof Kozlowski:
> On 28/11/2025 17:15, Josua Mayer wrote:
>> Add mux controller support for when sdio lines are muxed between a host
>> and multiple cards.
>>
>> There are several devices supporting a choice of eMMC or SD on a single
>> board by both dip switch and gpio, e.g. Renesas RZ/G2L SMARC SoM and
>> SolidRun RZ/G2L SoM.
>>
>> In-tree dts for the Renesas boards currently rely on preprocessor macros
>> to hog gpios and define the card.
>>
>> By adding mux-states property to sdio controller description, boards can
>> correctly describe the mux that already exists in hardware - and drivers
>> can coordinate between mux selection and probing for cards.
>>
>> Signed-off-by: Josua Mayer <josua@solid-run.com>
>> ---
>>  Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml | 14 ++++++++++++++
>>  1 file changed, 14 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
>> index c754ea71f51f7..55635c60ad73a 100644
>> --- a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
>> +++ b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
>> @@ -106,6 +106,11 @@ properties:
>>    iommus:
>>      maxItems: 1
>>  
>> +  mux-states:
>> +    description:
>> +      mux controller node to route the SDIO signals from SoC to cards.
>> +    maxItems: 1
>> +
>>    power-domains:
>>      maxItems: 1
>>  
>> @@ -262,9 +267,17 @@ unevaluatedProperties: false
>>  examples:
>>    - |
>>      #include <dt-bindings/clock/r8a7790-cpg-mssr.h>
>> +    #include <dt-bindings/gpio/gpio.h>
>>      #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +    #include <dt-bindings/pinctrl/rzg2l-pinctrl.h>
>>      #include <dt-bindings/power/r8a7790-sysc.h>
>>  
>> +    mux: mux-controller {
>> +            compatible = "gpio-mux";
>> +            #mux-state-cells = <1>;
>> +            mux-gpios = <&pinctrl RZG2L_GPIO(22, 1) GPIO_ACTIVE_LOW>;
>
> Wrong indentation and not really relevant here, so just drop.
Ack.
>
> Best regards,
> Krzysztof