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[v11,3/4] HID: cp2112: Fwnode Support

Message ID 20240605-cp2112-dt-v11-3-d55f0f945a62@plexus.com (mailing list archive)
State New
Delegated to: Jiri Kosina
Headers show
Series Firmware Support for USB-HID Devices and CP2112 | expand

Commit Message

Danny Kaehn June 5, 2024, 11:12 p.m. UTC
Support describing the CP2112's I2C and GPIO interfaces in firmware.

The GPIO chip shares a firmware node with the CP2112. The I2C child
node can either be a child with the name "i2c" or, in ACPI, a device
node with _ADR Zero.

Signed-off-by: Danny Kaehn <danny.kaehn@plexus.com>
---
 drivers/hid/hid-cp2112.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
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Patch

diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index 20a0d1315d90..b78d81275065 100644
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -27,6 +27,22 @@ 
 #include <linux/usb/ch9.h>
 #include "hid-ids.h"
 
+/**
+ * enum cp2112_child_acpi_cell_addrs - Child ACPI addresses for CP2112 sub-functions
+ * @CP2112_I2C_ADR: Address for I2C node
+ */
+enum cp2112_child_acpi_cell_addrs {
+	CP2112_I2C_ADR = 0,
+};
+
+/*
+ * CP2112 Fwnode child names.
+ * CP2112 sub-functions can be described by named fwnode children or by ACPI _ADR
+ */
+static const char * const cp2112_cell_names[] = {
+	[CP2112_I2C_ADR]	= "i2c",
+};
+
 #define CP2112_REPORT_MAX_LENGTH		64
 #define CP2112_GPIO_CONFIG_LENGTH		5
 #define CP2112_GPIO_GET_LENGTH			2
@@ -1195,7 +1211,10 @@  static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	struct cp2112_device *dev;
 	u8 buf[3];
 	struct cp2112_smbus_config_report config;
+	struct fwnode_handle *child;
 	struct gpio_irq_chip *girq;
+	const char *name;
+	u32 addr;
 	int ret;
 
 	dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
@@ -1209,6 +1228,26 @@  static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 
 	mutex_init(&dev->lock);
 
+	device_for_each_child_node(&hdev->dev, child) {
+		ret = acpi_get_local_address(ACPI_HANDLE_FWNODE(child), &addr);
+		if (ret) {
+			name = fwnode_get_name(child);
+			if (!name)
+				continue;
+			ret = match_string(cp2112_cell_names,
+					ARRAY_SIZE(cp2112_cell_names), name);
+			if (ret < 0)
+				continue;
+			addr = ret;
+		}
+
+		switch (addr) {
+		case CP2112_I2C_ADR:
+			device_set_node(&dev->adap.dev, child);
+			break;
+		}
+	}
+
 	ret = hid_parse(hdev);
 	if (ret) {
 		hid_err(hdev, "parse failed\n");