linux-kernel - [PATCH v1 3/3] mfd: cros_ec: Don't add cros_ec

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Message-ID: <20250312195951.1579682-4-jthies@google.com>
Date: Wed, 12 Mar 2025 19:59:12 +0000
From: Jameson Thies <jthies@...gle.com>
To: tzungbi@...nel.org, ukaszb@...omium.org, bleung@...omium.org, 
	heikki.krogerus@...ux.intel.com, robh+dt@...nel.org, 
	krzysztof.kozlowski+dt@...aro.org, groeck@...omium.org, swboyd@...omium.org, 
	akuchynski@...omium.org
Cc: devicetree@...r.kernel.org, chrome-platform@...ts.linux.dev, 
	linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org, 
	Jameson Thies <jthies@...gle.com>
Subject: [PATCH v1 3/3] mfd: cros_ec: Don't add cros_ec_ucsi if it is defined
 in OF or ACPI

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.

Signed-off-by: Jameson Thies <jthies@...gle.com>
---
 drivers/mfd/cros_ec_dev.c | 39 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index 9f84a52b48d6..5fb6cd20c5ec 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>
@@ -128,11 +129,6 @@ 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,
@@ -169,6 +165,15 @@ static const struct mfd_cell cros_ec_vbc_cells[] = {
 	{ .name = "cros-ec-vbc", }
 };
 
+
+static int ucsi_acpi_match(struct device *dev, void *data)
+{
+	struct acpi_device_id ucsi_acpi_device_ids[] = {
+		{ "GOOG0021", 0 },
+	};
+	return !!acpi_match_device(ucsi_acpi_device_ids, dev);
+}
+
 static void cros_ec_class_release(struct device *dev)
 {
 	kfree(to_cros_ec_dev(dev));
@@ -256,6 +261,30 @@ 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)) {
+		struct device *acpi_dev = device_find_child(ec->ec_dev->dev,
+							    NULL,
+							    ucsi_acpi_match);
+
+		if (!!acpi_dev) {
+			put_device(acpi_dev);
+		} else if (!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.
-- 
2.49.0.rc0.332.g42c0ae87b1-goog