[PATCH 0/3] Add PMI8998 VBUS Regulator Support

[PATCH 0/3] Add PMI8998 VBUS Regulator Support

[James A. MacInnes]

Hello,

This patch series adds support for the PMI8998 VBUS regulator in the Qualcomm USB VBUS regulator driver and the device tree. These changes enable proper VBUS current limit configuration and ensure compatibility across multiple Qualcomm PMICs.

Summary of Changes:
- Patch 1/3: Updates the Device Tree Schema bindings to include "qcom,pmi8998-vbus-reg" for PMI8998 support.
- Patch 2/3: Extends the Qualcomm USB VBUS regulator driver to support PMI8998, dynamically configuring the regulator based on the PMIC type.
- Patch 3/3: Adds the VBUS regulator node to pmi8998.dtsi, enabling USB Type-C VBUS support.

Motivation:
A long time ago, in a conference room far, far away, I promised that USB Type-C capability would work on the SDM845 when we chose this chip for our instrument.

That day never came.

So I wrote it myself.

This patch series finally adds the missing support for USB Type-C VBUS regulation on PMI8998-based platforms. Future generations of engineers will no longer have to mutter "Why doesn’t this work?" while digging through device trees.

Kernel Version & Testing:
- These patches were developed and tested on Linux 6.13.
- Attempting to run Linux 6.14-rc2 on our Lantronix SOM resulted in a crash, making it unsuitable for validation.
- Validation was performed using a modified device tree, confirming proper regulator configuration.
- No regressions were observed on existing PMIC configurations.

Next Steps:
If there are any suggestions or required changes, please let me know. I will be happy to revise and address any concerns.

Thanks again,
James A. MacInnes
james.a.macinnes@gmail.com

James A. MacInnes (3):
  regulator: qcom_usb_vbus: Update DTS binding for PMI8998 support
  regulator: qcom_usb_vbus: Add support for PMI8998 VBUS
  arm64: boot: dts: pmi8998.dtsi: Add VBUS regulator

 .../regulator/qcom,usb-vbus-regulator.yaml    |  1 +
 arch/arm64/boot/dts/qcom/pmi8998.dtsi         |  6 ++++
 drivers/regulator/qcom_usb_vbus-regulator.c   | 33 ++++++++++++++++---
 3 files changed, 35 insertions(+), 5 deletions(-)

-- 
2.43.0

[PATCH 1/3] regulator: qcom_usb_vbus: Update DTS binding for PMI8998 support

[James A. MacInnes]

Update the binding in
Documentation/devicetree/bindings/regulator/qcom,usb-vbus-regulator.yaml
to include the compatible string "qcom,pmi8998-vbus-reg".
This change adds PMI8998 support to the Qualcomm USB VBUS regulator
bindings.

With this patch, device trees that describe a PMI8998 USB VBUS regulator
using the "qcom,pmi8998-vbus-reg" compatible string will now validate
correctly. This is required to support hardware based on PMI8998, which
has different current limit tables and other regulator-specific
configurations.

Tested: The next patch contains the driver and has been tested with
Lantronix SOM.

Signed-off-by: James A. MacInnes <james.a.macinnes@gmail.com>
---
 .../devicetree/bindings/regulator/qcom,usb-vbus-regulator.yaml   | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/regulator/qcom,usb-vbus-regulator.yaml b/Documentation/devicetree/bindings/regulator/qcom,usb-vbus-regulator.yaml
index fcefc722ee2a..6092560e9048 100644
--- a/Documentation/devicetree/bindings/regulator/qcom,usb-vbus-regulator.yaml
+++ b/Documentation/devicetree/bindings/regulator/qcom,usb-vbus-regulator.yaml
@@ -22,6 +22,7 @@ properties:
     oneOf:
       - enum:
           - qcom,pm8150b-vbus-reg
+          - qcom,pmi8998-vbus-reg
       - items:
           - enum:
               - qcom,pm4125-vbus-reg
-- 
2.43.0

[PATCH 2/3] regulator: qcom_usb_vbus: Add support for PMI8998 VBUS

[James A. MacInnes]

This patch extends the Qualcomm USB VBUS regulator driver to support
PMI8998 PMIC alongside the existing support for PM8150B.

Key changes:
- Added current limit tables specific to PMI8998.
- Dynamically configure the VBUS regulator based on the PMIC type.
- Updated debug messages to reflect successful initialization for
  supported PMICs.
- Changed registration log message

These changes ensure proper VBUS current limit configuration and
compatibility across multiple Qualcomm PMICs.

Signed-off-by: James A. MacInnes <james.a.macinnes@gmail.com>
---
 drivers/regulator/qcom_usb_vbus-regulator.c | 33 +++++++++++++++++----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/drivers/regulator/qcom_usb_vbus-regulator.c b/drivers/regulator/qcom_usb_vbus-regulator.c
index cd94ed67621f..bfcb77698ba2 100644
--- a/drivers/regulator/qcom_usb_vbus-regulator.c
+++ b/drivers/regulator/qcom_usb_vbus-regulator.c
@@ -20,10 +20,15 @@
 #define OTG_CFG				0x53
 #define OTG_EN_SRC_CFG			BIT(1)
 
-static const unsigned int curr_table[] = {
+static const unsigned int curr_table_pm8150b[] = {
 	500000, 1000000, 1500000, 2000000, 2500000, 3000000,
 };
 
+static const unsigned int curr_table_pmi8998[] = {
+	250000, 500000, 750000, 1000000,
+	1250000, 1500000, 1750000, 2000000,
+};
+
 static const struct regulator_ops qcom_usb_vbus_reg_ops = {
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
@@ -37,8 +42,8 @@ static struct regulator_desc qcom_usb_vbus_rdesc = {
 	.ops = &qcom_usb_vbus_reg_ops,
 	.owner = THIS_MODULE,
 	.type = REGULATOR_VOLTAGE,
-	.curr_table = curr_table,
-	.n_current_limits = ARRAY_SIZE(curr_table),
+	.curr_table = NULL,
+	.n_current_limits = 0,
 };
 
 static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
@@ -50,6 +55,7 @@ static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
 	struct regulator_init_data *init_data;
 	int ret;
 	u32 base;
+	const char *pmic_type;
 
 	ret = of_property_read_u32(dev->of_node, "reg", &base);
 	if (ret < 0) {
@@ -68,6 +74,19 @@ static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
 	if (!init_data)
 		return -ENOMEM;
 
+	// Determine PMIC type
+	pmic_type = of_device_get_match_data(dev);
+	if (pmic_type && strcmp(pmic_type, "pmi8998") == 0) {
+		qcom_usb_vbus_rdesc.curr_table = curr_table_pmi8998;
+		qcom_usb_vbus_rdesc.n_current_limits =
+			ARRAY_SIZE(curr_table_pmi8998);
+	} else if (pmic_type && strcmp(pmic_type, "pm8150b") == 0) {
+		qcom_usb_vbus_rdesc.curr_table = curr_table_pm8150b;
+		qcom_usb_vbus_rdesc.n_current_limits =
+			ARRAY_SIZE(curr_table_pm8150b);
+	} else {
+		return -ENODEV;
+	}
 	qcom_usb_vbus_rdesc.enable_reg = base + CMD_OTG;
 	qcom_usb_vbus_rdesc.enable_mask = OTG_EN;
 	qcom_usb_vbus_rdesc.csel_reg = base + OTG_CURRENT_LIMIT_CFG;
@@ -80,18 +99,22 @@ static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
 	rdev = devm_regulator_register(dev, &qcom_usb_vbus_rdesc, &config);
 	if (IS_ERR(rdev)) {
 		ret = PTR_ERR(rdev);
-		dev_err(dev, "not able to register vbus reg %d\n", ret);
+		dev_err(dev, "Failed to register vbus reg %d\n", ret);
 		return ret;
 	}
 
 	/* Disable HW logic for VBUS enable */
 	regmap_update_bits(regmap, base + OTG_CFG, OTG_EN_SRC_CFG, 0);
 
+	dev_info(dev, "Registered QCOM %s VBUS regulator\n",
+		 pmic_type);
+
 	return 0;
 }
 
 static const struct of_device_id qcom_usb_vbus_regulator_match[] = {
-	{ .compatible = "qcom,pm8150b-vbus-reg" },
+	{ .compatible = "qcom,pm8150b-vbus-reg", .data = "pm8150b" },
+	{ .compatible = "qcom,pmi8998-vbus-reg", .data = "pmi8998" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, qcom_usb_vbus_regulator_match);
-- 
2.43.0

[PATCH 3/3] arm64: boot: dts: pmi8998.dtsi: Add VBUS regulator

[James A. MacInnes]

This patch adds support for the USB Type-C VBUS regulator to the
PMI8998 PMIC device tree.

Key changes:
- Defined the `usb-vbus-regulator` node for VBUS handling, enabling
  control over USB power delivery.

This addition enable USB Type-C VBUS support on sdm845 platforms.

Signed-off-by: James A. MacInnes <james.a.macinnes@gmail.com>
---
 arch/arm64/boot/dts/qcom/pmi8998.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/pmi8998.dtsi b/arch/arm64/boot/dts/qcom/pmi8998.dtsi
index cd3f0790fd42..8cb1d851b5a3 100644
--- a/arch/arm64/boot/dts/qcom/pmi8998.dtsi
+++ b/arch/arm64/boot/dts/qcom/pmi8998.dtsi
@@ -29,6 +29,12 @@ pmi8998_charger: charger@1000 {
 			status = "disabled";
 		};
 
+		pmi8998_vbus: usb-vbus-regulator@1100 {
+			compatible = "qcom,pmi8998-vbus-reg";
+			status = "disabled";
+			reg = <0x1100>;
+		};
+
 		pmi8998_gpios: gpio@c000 {
 			compatible = "qcom,pmi8998-gpio", "qcom,spmi-gpio";
 			reg = <0xc000>;
-- 
2.43.0

Re: [PATCH 2/3] regulator: qcom_usb_vbus: Add support for PMI8998 VBUS

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 1507 bytes --]

On Tue, Feb 11, 2025 at 11:49:15AM -0800, James A. MacInnes wrote:

> -	.curr_table = curr_table,
> -	.n_current_limits = ARRAY_SIZE(curr_table),
> +	.curr_table = NULL,
> +	.n_current_limits = 0,

Things that are not initialised in static variables are implicitly 0.

> +	// Determine PMIC type
> +	pmic_type = of_device_get_match_data(dev);
> +	if (pmic_type && strcmp(pmic_type, "pmi8998") == 0) {
> +		qcom_usb_vbus_rdesc.curr_table = curr_table_pmi8998;
> +		qcom_usb_vbus_rdesc.n_current_limits =
> +			ARRAY_SIZE(curr_table_pmi8998);
> +	} else if (pmic_type && strcmp(pmic_type, "pm8150b") == 0) {
> +		qcom_usb_vbus_rdesc.curr_table = curr_table_pm8150b;
> +		qcom_usb_vbus_rdesc.n_current_limits =
> +			ARRAY_SIZE(curr_table_pm8150b);
> +	} else {
> +		return -ENODEV;
> +	}

Instead of modifying the static variable (which you had to remove const
from...) the driver should take a copy of it and modify that, that way
nothing goes wrong if we get two of the devices or anything.

>  static const struct of_device_id qcom_usb_vbus_regulator_match[] = {
> -	{ .compatible = "qcom,pm8150b-vbus-reg" },
> +	{ .compatible = "qcom,pm8150b-vbus-reg", .data = "pm8150b" },
> +	{ .compatible = "qcom,pmi8998-vbus-reg", .data = "pmi8998" },

The driver data should be a pointer to some quirk data for the device,
if you want a string to identify the device that should be a member of
the quirk data struct.  This will make the use of the data safer and
more idiomatic.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH 2/3] regulator: qcom_usb_vbus: Add support for PMI8998 VBUS

[Dmitry Baryshkov]

On Tue, Feb 11, 2025 at 11:49:15AM -0800, James A. MacInnes wrote:
> This patch extends the Qualcomm USB VBUS regulator driver to support
> PMI8998 PMIC alongside the existing support for PM8150B.
> 
> Key changes:
> - Added current limit tables specific to PMI8998.
> - Dynamically configure the VBUS regulator based on the PMIC type.
> - Updated debug messages to reflect successful initialization for
>   supported PMICs.
> - Changed registration log message
> 
> These changes ensure proper VBUS current limit configuration and
> compatibility across multiple Qualcomm PMICs.
> 
> Signed-off-by: James A. MacInnes <james.a.macinnes@gmail.com>
> ---
>  drivers/regulator/qcom_usb_vbus-regulator.c | 33 +++++++++++++++++----
>  1 file changed, 28 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/regulator/qcom_usb_vbus-regulator.c b/drivers/regulator/qcom_usb_vbus-regulator.c
> index cd94ed67621f..bfcb77698ba2 100644
> --- a/drivers/regulator/qcom_usb_vbus-regulator.c
> +++ b/drivers/regulator/qcom_usb_vbus-regulator.c
> @@ -20,10 +20,15 @@
>  #define OTG_CFG				0x53
>  #define OTG_EN_SRC_CFG			BIT(1)
>  
> -static const unsigned int curr_table[] = {
> +static const unsigned int curr_table_pm8150b[] = {
>  	500000, 1000000, 1500000, 2000000, 2500000, 3000000,
>  };
>  
> +static const unsigned int curr_table_pmi8998[] = {
> +	250000, 500000, 750000, 1000000,
> +	1250000, 1500000, 1750000, 2000000,
> +};
> +
>  static const struct regulator_ops qcom_usb_vbus_reg_ops = {
>  	.enable = regulator_enable_regmap,
>  	.disable = regulator_disable_regmap,
> @@ -37,8 +42,8 @@ static struct regulator_desc qcom_usb_vbus_rdesc = {
>  	.ops = &qcom_usb_vbus_reg_ops,
>  	.owner = THIS_MODULE,
>  	.type = REGULATOR_VOLTAGE,
> -	.curr_table = curr_table,
> -	.n_current_limits = ARRAY_SIZE(curr_table),
> +	.curr_table = NULL,
> +	.n_current_limits = 0,
>  };
>  
>  static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
> @@ -50,6 +55,7 @@ static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
>  	struct regulator_init_data *init_data;
>  	int ret;
>  	u32 base;
> +	const char *pmic_type;
>  
>  	ret = of_property_read_u32(dev->of_node, "reg", &base);
>  	if (ret < 0) {
> @@ -68,6 +74,19 @@ static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
>  	if (!init_data)
>  		return -ENOMEM;
>  
> +	// Determine PMIC type
> +	pmic_type = of_device_get_match_data(dev);
> +	if (pmic_type && strcmp(pmic_type, "pmi8998") == 0) {

I think a traditional way is to define an enum and then use that enum
values as match data. Or you can just add a struct with curr_table and
get that as a match data.

> +		qcom_usb_vbus_rdesc.curr_table = curr_table_pmi8998;
> +		qcom_usb_vbus_rdesc.n_current_limits =
> +			ARRAY_SIZE(curr_table_pmi8998);
> +	} else if (pmic_type && strcmp(pmic_type, "pm8150b") == 0) {
> +		qcom_usb_vbus_rdesc.curr_table = curr_table_pm8150b;
> +		qcom_usb_vbus_rdesc.n_current_limits =
> +			ARRAY_SIZE(curr_table_pm8150b);
> +	} else {
> +		return -ENODEV;
> +	}
>  	qcom_usb_vbus_rdesc.enable_reg = base + CMD_OTG;
>  	qcom_usb_vbus_rdesc.enable_mask = OTG_EN;
>  	qcom_usb_vbus_rdesc.csel_reg = base + OTG_CURRENT_LIMIT_CFG;
> @@ -80,18 +99,22 @@ static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
>  	rdev = devm_regulator_register(dev, &qcom_usb_vbus_rdesc, &config);
>  	if (IS_ERR(rdev)) {
>  		ret = PTR_ERR(rdev);
> -		dev_err(dev, "not able to register vbus reg %d\n", ret);
> +		dev_err(dev, "Failed to register vbus reg %d\n", ret);
>  		return ret;
>  	}
>  
>  	/* Disable HW logic for VBUS enable */
>  	regmap_update_bits(regmap, base + OTG_CFG, OTG_EN_SRC_CFG, 0);
>  
> +	dev_info(dev, "Registered QCOM %s VBUS regulator\n",
> +		 pmic_type);

dev_dbg, the driver should be silent by default.

> +
>  	return 0;
>  }
>  
>  static const struct of_device_id qcom_usb_vbus_regulator_match[] = {
> -	{ .compatible = "qcom,pm8150b-vbus-reg" },
> +	{ .compatible = "qcom,pm8150b-vbus-reg", .data = "pm8150b" },
> +	{ .compatible = "qcom,pmi8998-vbus-reg", .data = "pmi8998" },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(of, qcom_usb_vbus_regulator_match);
> -- 
> 2.43.0
> 

-- 
With best wishes
Dmitry

Re: [PATCH 3/3] arm64: boot: dts: pmi8998.dtsi: Add VBUS regulator

[Dmitry Baryshkov]

On Tue, Feb 11, 2025 at 11:49:16AM -0800, James A. MacInnes wrote:
> This patch adds support for the USB Type-C VBUS regulator to the
> PMI8998 PMIC device tree.

"In order to enable USB Type-C VBUS support on the SDM845 platform add
device node for the USB Vbus regulator to the PMI8998 PMIC device tree."

Drop the rest of the commit message.

> 
> Key changes:
> - Defined the `usb-vbus-regulator` node for VBUS handling, enabling
>   control over USB power delivery.
> 
> This addition enable USB Type-C VBUS support on sdm845 platforms.
> 
> Signed-off-by: James A. MacInnes <james.a.macinnes@gmail.com>
> ---
>  arch/arm64/boot/dts/qcom/pmi8998.dtsi | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/pmi8998.dtsi b/arch/arm64/boot/dts/qcom/pmi8998.dtsi
> index cd3f0790fd42..8cb1d851b5a3 100644
> --- a/arch/arm64/boot/dts/qcom/pmi8998.dtsi
> +++ b/arch/arm64/boot/dts/qcom/pmi8998.dtsi
> @@ -29,6 +29,12 @@ pmi8998_charger: charger@1000 {
>  			status = "disabled";
>  		};
>  
> +		pmi8998_vbus: usb-vbus-regulator@1100 {
> +			compatible = "qcom,pmi8998-vbus-reg";
> +			status = "disabled";
> +			reg = <0x1100>;
> +		};
> +
>  		pmi8998_gpios: gpio@c000 {
>  			compatible = "qcom,pmi8998-gpio", "qcom,spmi-gpio";
>  			reg = <0xc000>;
> -- 
> 2.43.0
> 

-- 
With best wishes
Dmitry

Re: [PATCH 2/3] regulator: qcom_usb_vbus: Add support for PMI8998 VBUS

[Bryan O'Donoghue]

On 11/02/2025 19:49, James A. MacInnes wrote:
> +	// Determine PMIC type
> +	pmic_type = of_device_get_match_data(dev);
> +	if (pmic_type && strcmp(pmic_type, "pmi8998") == 0) {
> +		qcom_usb_vbus_rdesc.curr_table = curr_table_pmi8998;
> +		qcom_usb_vbus_rdesc.n_current_limits =
> +			ARRAY_SIZE(curr_table_pmi8998);
> +	} else if (pmic_type && strcmp(pmic_type, "pm8150b") == 0) {
> +		qcom_usb_vbus_rdesc.curr_table = curr_table_pm8150b;
> +		qcom_usb_vbus_rdesc.n_current_limits =
> +			ARRAY_SIZE(curr_table_pm8150b);
> +	} else {
> +		return -ENODEV;
> +	}
>   	qcom_usb_vbus_rdesc.enable_reg = base + CMD_OTG;
>   	qcom_usb_vbus_rdesc.enable_mask = OTG_EN;
>   	qcom_usb_vbus_rdesc.csel_reg = base + OTG_CURRENT_LIMIT_CFG;
> @@ -80,18 +99,22 @@ static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
>   	rdev = devm_regulator_register(dev, &qcom_usb_vbus_rdesc, &config);
>   	if (IS_ERR(rdev)) {
>   		ret = PTR_ERR(rdev);
> -		dev_err(dev, "not able to register vbus reg %d\n", ret);
> +		dev_err(dev, "Failed to register vbus reg %d\n", ret);
>   		return ret;
>   	}
>   
>   	/* Disable HW logic for VBUS enable */
>   	regmap_update_bits(regmap, base + OTG_CFG, OTG_EN_SRC_CFG, 0);
>   
> +	dev_info(dev, "Registered QCOM %s VBUS regulator\n",
> +		 pmic_type);
> +
>   	return 0;
>   }
>   
>   static const struct of_device_id qcom_usb_vbus_regulator_match[] = {
> -	{ .compatible = "qcom,pm8150b-vbus-reg" },
> +	{ .compatible = "qcom,pm8150b-vbus-reg", .data = "pm8150b" },
> +	{ .compatible = "qcom,pmi8998-vbus-reg", .data = "pmi8998" },

I think the other two said much the same thing but .data should point to 
the differentiator instead of being a string which you disjoin on and 
then hook your differentiated data.

i.e.

.data = &my_driver_specific_static_data_here.

---
bod

Re: [PATCH 2/3] regulator: qcom_usb_vbus: Add support for PMI8998 VBUS

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 449 bytes --]

On Wed, Feb 12, 2025 at 01:16:37AM +0200, Dmitry Baryshkov wrote:
> On Tue, Feb 11, 2025 at 11:49:15AM -0800, James A. MacInnes wrote:

> > +	pmic_type = of_device_get_match_data(dev);
> > +	if (pmic_type && strcmp(pmic_type, "pmi8998") == 0) {

> I think a traditional way is to define an enum and then use that enum
> values as match data. Or you can just add a struct with curr_table and
> get that as a match data.

Either approach works, yeah.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]