platform/surface: Add OF support

Add basic support for registering the aggregator module on Device Tree-
based platforms. These include at least three generations of Qualcomm
Snapdragon-based Surface devices:

- SC8180X / SQ1 / SQ2: Pro X,
- SC8280XP / SQ3: Devkit 2023, Pro 9
- X Elite: Laptop 7 / Pro11

Thankfully, the aggregators on these seem to be configured in an
identical way, which allows for using these settings as defaults and
no DT properties need to be introduced (until that changes, anyway).

Based on the work done by Maximilian Luz, largely rewritten.

Signed-off-by: Konrad Dybcio <[email protected]>
Reviewed-by: Maximilian Luz <[email protected]>
Tested-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

1 files changed, 40 insertions, 5 deletions

diff --git a/drivers/platform/surface/surface_aggregator_registry.c b/drivers/platform/surface/surface_aggregator_registry.c
index 1c4d74db08c9..ac96e883cb57 100644
--- a/drivers/platform/surface/surface_aggregator_registry.c
+++ b/drivers/platform/surface/surface_aggregator_registry.c
@@ -12,6 +12,7 @@
 #include <linux/acpi.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/types.h>
@@ -273,6 +274,18 @@ static const struct software_node *ssam_node_group_sl5[] = {
 	NULL,
 };
 
+/* Devices for Surface Laptop 7. */
+static const struct software_node *ssam_node_group_sl7[] = {
+	&ssam_node_root,
+	&ssam_node_bat_ac,
+	&ssam_node_bat_main,
+	&ssam_node_tmp_perf_profile_with_fan,
+	&ssam_node_fan_speed,
+	&ssam_node_hid_sam_keyboard,
+	/* TODO: evaluate thermal sensors devices when we get a driver for that */
+	NULL,
+};
+
 /* Devices for Surface Laptop Studio. */
 static const struct software_node *ssam_node_group_sls[] = {
 	&ssam_node_root,
@@ -346,7 +359,7 @@ static const struct software_node *ssam_node_group_sp9[] = {
 
 /* -- SSAM platform/meta-hub driver. ---------------------------------------- */
 
-static const struct acpi_device_id ssam_platform_hub_match[] = {
+static const struct acpi_device_id ssam_platform_hub_acpi_match[] = {
 	/* Surface Pro 4, 5, and 6 (OMBR < 0x10) */
 	{ "MSHW0081", (unsigned long)ssam_node_group_gen5 },
 
@@ -400,18 +413,39 @@ static const struct acpi_device_id ssam_platform_hub_match[] = {
 
 	{ },
 };
-MODULE_DEVICE_TABLE(acpi, ssam_platform_hub_match);
+MODULE_DEVICE_TABLE(acpi, ssam_platform_hub_acpi_match);
+
+static const struct of_device_id ssam_platform_hub_of_match[] __maybe_unused = {
+	/* Surface Laptop 7 */
+	{ .compatible = "microsoft,romulus13", (void *)ssam_node_group_sl7 },
+	{ .compatible = "microsoft,romulus15", (void *)ssam_node_group_sl7 },
+	{ },
+};
 
 static int ssam_platform_hub_probe(struct platform_device *pdev)
 {
 	const struct software_node **nodes;
+	const struct of_device_id *match;
+	struct device_node *fdt_root;
 	struct ssam_controller *ctrl;
 	struct fwnode_handle *root;
 	int status;
 
 	nodes = (const struct software_node **)acpi_device_get_match_data(&pdev->dev);
-	if (!nodes)
-		return -ENODEV;
+	if (!nodes) {
+		fdt_root = of_find_node_by_path("/");
+		if (!fdt_root)
+			return -ENODEV;
+
+		match = of_match_node(ssam_platform_hub_of_match, fdt_root);
+		of_node_put(fdt_root);
+		if (!match)
+			return -ENODEV;
+
+		nodes = (const struct software_node **)match->data;
+		if (!nodes)
+			return -ENODEV;
+	}
 
 	/*
 	 * As we're adding the SSAM client devices as children under this device
@@ -460,12 +494,13 @@ static struct platform_driver ssam_platform_hub_driver = {
 	.remove_new = ssam_platform_hub_remove,
 	.driver = {
 		.name = "surface_aggregator_platform_hub",
-		.acpi_match_table = ssam_platform_hub_match,
+		.acpi_match_table = ssam_platform_hub_acpi_match,
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},
 };
 module_platform_driver(ssam_platform_hub_driver);
 
+MODULE_ALIAS("platform:surface_aggregator_platform_hub");
 MODULE_AUTHOR("Maximilian Luz <[email protected]>");
 MODULE_DESCRIPTION("Device-registry for Surface System Aggregator Module");
 MODULE_LICENSE("GPL");