[PATCH v1 0/1] Check for UCSI fwnode in cros_ec_dev

[PATCH v1 0/1] Check for UCSI fwnode in cros_ec_dev

[Jameson Thies]

Hey everyone, 
I sent this patch as part of a larger series in late 2025 which hasn't
merged. The initial series modified dt-bindings, mfd and usb subsystems,
but had not been reviewed by mfd maintainers.

For context, here is the previous series
https://lore.kernel.org/all/20251013203331.398517-1-jthies@google.com/

This is only the mfd portion of that series, it builds independently.

Given the time since this was previously under review (~oct 2025), I've
cleared the existing review tags. Please take a look and let me know if
you have any questions.

Jameson Thies (1):
  mfd: cros_ec: Don't add cros_ec_ucsi if it is defined in OF or ACPI

 drivers/mfd/cros_ec_dev.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)


base-commit: 168e4b208ca8c2e04de20cc6cb7e2fb035dc1ec8
-- 
2.53.0.1213.gd9a14994de-goog

[PATCH v1 1/1] mfd: cros_ec: Don't add cros_ec_ucsi if it is defined in OF or ACPI

[Jameson Thies]

On devices with a UCSI PPM in the EC, check for cros_ec_ucsi to be
defined in the OF device tree or an ACPI node. If it is defined by
either OF or ACPI, it does not need to be added as a subdevice of
cros_ec_dev mfd. cros_ec_ucsi will load from the OF or ACPI node.

Signed-off-by: Jameson Thies <jthies@google.com>
---
 drivers/mfd/cros_ec_dev.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index 39430dd44e30..70d64b7c6243 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2014 Google, Inc.
  */
 
+#include <linux/acpi.h>
 #include <linux/dmi.h>
 #include <linux/kconfig.h>
 #include <linux/mfd/core.h>
@@ -131,11 +132,6 @@ static const struct cros_feature_to_cells cros_subdevices[] = {
 		.mfd_cells	= cros_ec_rtc_cells,
 		.num_cells	= ARRAY_SIZE(cros_ec_rtc_cells),
 	},
-	{
-		.id		= EC_FEATURE_UCSI_PPM,
-		.mfd_cells	= cros_ec_ucsi_cells,
-		.num_cells	= ARRAY_SIZE(cros_ec_ucsi_cells),
-	},
 	{
 		.id		= EC_FEATURE_HANG_DETECT,
 		.mfd_cells	= cros_ec_wdt_cells,
@@ -264,6 +260,23 @@ static int ec_device_probe(struct platform_device *pdev)
 		}
 	}
 
+	/*
+	 * FW nodes can load cros_ec_ucsi, but early PDC devices did not define
+	 * the required nodes. On PDC systems without FW nodes for cros_ec_ucsi,
+	 * the driver should be added as an mfd subdevice.
+	 */
+	if (cros_ec_check_features(ec, EC_FEATURE_USB_PD) &&
+	    cros_ec_check_features(ec, EC_FEATURE_UCSI_PPM) &&
+	    !acpi_dev_found("GOOG0021") &&
+	    !of_find_compatible_node(NULL, NULL, "google,cros-ec-ucsi")) {
+		retval = mfd_add_hotplug_devices(ec->dev,
+						 cros_ec_ucsi_cells,
+						 ARRAY_SIZE(cros_ec_ucsi_cells));
+
+		if (retval)
+			dev_warn(ec->dev, "failed to add cros_ec_ucsi: %d\n", retval);
+	}
+
 	/*
 	 * UCSI provides power supply information so we don't need to separately
 	 * load the cros_usbpd_charger driver.
-- 
2.53.0.1213.gd9a14994de-goog

Re: [PATCH v1 1/1] mfd: cros_ec: Don't add cros_ec_ucsi if it is defined in OF or ACPI

[Benson Leung]

[-- Attachment #1: Type: text/plain, Size: 2313 bytes --]

On Fri, Apr 03, 2026 at 10:22:53PM +0000, Jameson Thies wrote:
> On devices with a UCSI PPM in the EC, check for cros_ec_ucsi to be
> defined in the OF device tree or an ACPI node. If it is defined by
> either OF or ACPI, it does not need to be added as a subdevice of
> cros_ec_dev mfd. cros_ec_ucsi will load from the OF or ACPI node.
> 
> Signed-off-by: Jameson Thies <jthies@google.com>

Reviewed-by: Benson Leung <bleung@chromium.org>


> ---
>  drivers/mfd/cros_ec_dev.c | 23 ++++++++++++++++++-----
>  1 file changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
> index 39430dd44e30..70d64b7c6243 100644
> --- a/drivers/mfd/cros_ec_dev.c
> +++ b/drivers/mfd/cros_ec_dev.c
> @@ -5,6 +5,7 @@
>   * Copyright (C) 2014 Google, Inc.
>   */
>  
> +#include <linux/acpi.h>
>  #include <linux/dmi.h>
>  #include <linux/kconfig.h>
>  #include <linux/mfd/core.h>
> @@ -131,11 +132,6 @@ static const struct cros_feature_to_cells cros_subdevices[] = {
>  		.mfd_cells	= cros_ec_rtc_cells,
>  		.num_cells	= ARRAY_SIZE(cros_ec_rtc_cells),
>  	},
> -	{
> -		.id		= EC_FEATURE_UCSI_PPM,
> -		.mfd_cells	= cros_ec_ucsi_cells,
> -		.num_cells	= ARRAY_SIZE(cros_ec_ucsi_cells),
> -	},
>  	{
>  		.id		= EC_FEATURE_HANG_DETECT,
>  		.mfd_cells	= cros_ec_wdt_cells,
> @@ -264,6 +260,23 @@ static int ec_device_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> +	/*
> +	 * FW nodes can load cros_ec_ucsi, but early PDC devices did not define
> +	 * the required nodes. On PDC systems without FW nodes for cros_ec_ucsi,
> +	 * the driver should be added as an mfd subdevice.
> +	 */
> +	if (cros_ec_check_features(ec, EC_FEATURE_USB_PD) &&
> +	    cros_ec_check_features(ec, EC_FEATURE_UCSI_PPM) &&
> +	    !acpi_dev_found("GOOG0021") &&
> +	    !of_find_compatible_node(NULL, NULL, "google,cros-ec-ucsi")) {
> +		retval = mfd_add_hotplug_devices(ec->dev,
> +						 cros_ec_ucsi_cells,
> +						 ARRAY_SIZE(cros_ec_ucsi_cells));
> +
> +		if (retval)
> +			dev_warn(ec->dev, "failed to add cros_ec_ucsi: %d\n", retval);
> +	}
> +
>  	/*
>  	 * UCSI provides power supply information so we don't need to separately
>  	 * load the cros_usbpd_charger driver.
> -- 
> 2.53.0.1213.gd9a14994de-goog
> 

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