mfd: cros_ec: Add convenience struct to define dedicated CrOS EC MCUs

With the increasing use of dedicated CrOS EC MCUs, it takes a fair amount
of boiler plate code to add those devices, add a struct that can be used
to specify a dedicated CrOS EC MCU so we can just add a new item to it to
define a new dedicated MCU.
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/cros_ec_dev.c

@@ -23,6 +23,41 @@ static struct class cros_class = {
 	.name           = "chromeos",
 };
 
+/**
+ * cros_feature_to_name - CrOS feature id to name/short description.
+ * @id: The feature identifier.
+ * @name: Device name associated with the feature id.
+ * @desc: Short name that will be displayed.
+ */
+struct cros_feature_to_name {
+	unsigned int id;
+	const char *name;
+	const char *desc;
+};
+
+static const struct cros_feature_to_name cros_mcu_devices[] = {
+	{
+		.id	= EC_FEATURE_FINGERPRINT,
+		.name	= CROS_EC_DEV_FP_NAME,
+		.desc	= "Fingerprint",
+	},
+	{
+		.id	= EC_FEATURE_ISH,
+		.name	= CROS_EC_DEV_ISH_NAME,
+		.desc	= "Integrated Sensor Hub",
+	},
+	{
+		.id	= EC_FEATURE_SCP,
+		.name	= CROS_EC_DEV_SCP_NAME,
+		.desc	= "System Control Processor",
+	},
+	{
+		.id	= EC_FEATURE_TOUCHPAD,
+		.name	= CROS_EC_DEV_TP_NAME,
+		.desc	= "Touchpad",
+	},
+};
+
 static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
 {
 	struct cros_ec_command *msg;
@@ -279,6 +314,7 @@ static int ec_device_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
 	struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
+	int i;
 
 	if (!ec)
 		return retval;
@@ -291,47 +327,21 @@ static int ec_device_probe(struct platform_device *pdev)
 	ec->features[1] = -1U; /* Not cached yet */
 	device_initialize(&ec->class_dev);
 
-	/* Check whether this is actually a Fingerprint MCU rather than an EC */
-	if (cros_ec_check_features(ec, EC_FEATURE_FINGERPRINT)) {
-		dev_info(dev, "CrOS Fingerprint MCU detected.\n");
-		/*
-		 * Help userspace differentiating ECs from FP MCU,
-		 * regardless of the probing order.
-		 */
-		ec_platform->ec_name = CROS_EC_DEV_FP_NAME;
-	}
-
+	for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
 		/*
-	 * Check whether this is actually an Integrated Sensor Hub (ISH)
-	 * rather than an EC.
-	 */
-	if (cros_ec_check_features(ec, EC_FEATURE_ISH)) {
-		dev_info(dev, "CrOS ISH MCU detected.\n");
-		/*
-		 * Help userspace differentiating ECs from ISH MCU,
-		 * regardless of the probing order.
+		 * Check whether this is actually a dedicated MCU rather
+		 * than an standard EC.
 		 */
-		ec_platform->ec_name = CROS_EC_DEV_ISH_NAME;
-	}
-
-	/* Check whether this is actually a Touchpad MCU rather than an EC */
-	if (cros_ec_check_features(ec, EC_FEATURE_TOUCHPAD)) {
-		dev_info(dev, "CrOS Touchpad MCU detected.\n");
+		if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
+			dev_info(dev, "CrOS %s MCU detected\n",
+				 cros_mcu_devices[i].desc);
 			/*
-		 * Help userspace differentiating ECs from TP MCU,
+			 * Help userspace differentiating ECs from other MCU,
 			 * regardless of the probing order.
 			 */
-		ec_platform->ec_name = CROS_EC_DEV_TP_NAME;
+			ec_platform->ec_name = cros_mcu_devices[i].name;
+			break;
 		}
-
-	/* Check whether this is actually a SCP rather than an EC. */
-	if (cros_ec_check_features(ec, EC_FEATURE_SCP)) {
-		dev_info(dev, "CrOS SCP MCU detected.\n");
-		/*
-		 * Help userspace differentiating ECs from SCP,
-		 * regardless of the probing order.
-		 */
-		ec_platform->ec_name = CROS_EC_DEV_SCP_NAME;
 	}
 
 	/*