i2c: gpio: Add support on ACPI-based system

Add support for the ACPI-based device registration, so that the driver
can be also enabled through ACPI table.
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Tested-by: Peibao Liu <liupeibao@loongson.cn>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-gpio.c

@@ -13,9 +13,9 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
-#include <linux/of.h>
 #include <linux/platform_data/i2c-gpio.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 #include <linux/slab.h>
 
 struct i2c_gpio_private_data {
@@ -300,22 +300,23 @@ static inline void i2c_gpio_fault_injector_init(struct platform_device *pdev) {}
 static inline void i2c_gpio_fault_injector_exit(struct platform_device *pdev) {}
 #endif /* CONFIG_I2C_GPIO_FAULT_INJECTOR*/
 
-static void of_i2c_gpio_get_props(struct device_node *np,
+/* Get i2c-gpio properties from DT or ACPI table */
+static void i2c_gpio_get_properties(struct device *dev,
 				    struct i2c_gpio_platform_data *pdata)
 {
 	u32 reg;
 
-	of_property_read_u32(np, "i2c-gpio,delay-us", &pdata->udelay);
+	device_property_read_u32(dev, "i2c-gpio,delay-us", &pdata->udelay);
 
-	if (!of_property_read_u32(np, "i2c-gpio,timeout-ms", &reg))
+	if (!device_property_read_u32(dev, "i2c-gpio,timeout-ms", &reg))
 		pdata->timeout = msecs_to_jiffies(reg);
 
 	pdata->sda_is_open_drain =
-		of_property_read_bool(np, "i2c-gpio,sda-open-drain");
+		device_property_read_bool(dev, "i2c-gpio,sda-open-drain");
 	pdata->scl_is_open_drain =
-		of_property_read_bool(np, "i2c-gpio,scl-open-drain");
+		device_property_read_bool(dev, "i2c-gpio,scl-open-drain");
 	pdata->scl_is_output_only =
-		of_property_read_bool(np, "i2c-gpio,scl-output-only");
+		device_property_read_bool(dev, "i2c-gpio,scl-output-only");
 }
 
 static struct gpio_desc *i2c_gpio_get_desc(struct device *dev,
@@ -361,7 +362,7 @@ static int i2c_gpio_probe(struct platform_device *pdev)
 	struct i2c_algo_bit_data *bit_data;
 	struct i2c_adapter *adap;
 	struct device *dev = &pdev->dev;
-	struct device_node *np = dev->of_node;
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
 	enum gpiod_flags gflags;
 	int ret;
 
@@ -373,8 +374,8 @@ static int i2c_gpio_probe(struct platform_device *pdev)
 	bit_data = &priv->bit_data;
 	pdata = &priv->pdata;
 
-	if (np) {
-		of_i2c_gpio_get_props(np, pdata);
+	if (fwnode) {
+		i2c_gpio_get_properties(dev, pdata);
 	} else {
 		/*
 		 * If all platform data settings are zero it is OK
@@ -435,7 +436,7 @@ static int i2c_gpio_probe(struct platform_device *pdev)
 	bit_data->data = priv;
 
 	adap->owner = THIS_MODULE;
-	if (np)
+	if (fwnode)
 		strscpy(adap->name, dev_name(dev), sizeof(adap->name));
 	else
 		snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id);
@@ -443,7 +444,7 @@ static int i2c_gpio_probe(struct platform_device *pdev)
 	adap->algo_data = bit_data;
 	adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 	adap->dev.parent = dev;
-	adap->dev.of_node = np;
+	device_set_node(&adap->dev, fwnode);
 
 	adap->nr = pdev->id;
 	ret = i2c_bit_add_numbered_bus(adap);
@@ -489,10 +490,17 @@ static const struct of_device_id i2c_gpio_dt_ids[] = {
 
 MODULE_DEVICE_TABLE(of, i2c_gpio_dt_ids);
 
+static const struct acpi_device_id i2c_gpio_acpi_match[] = {
+	{ "LOON0005" }, /* LoongArch */
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, i2c_gpio_acpi_match);
+
 static struct platform_driver i2c_gpio_driver = {
 	.driver		= {
 		.name	= "i2c-gpio",
 		.of_match_table	= i2c_gpio_dt_ids,
+		.acpi_match_table = i2c_gpio_acpi_match,
 	},
 	.probe		= i2c_gpio_probe,
 	.remove		= i2c_gpio_remove,