Merge branch 'Enable-SFP-on-ACPI-based-systems'

Ruslan Babayev says:

====================
Enable SFP on ACPI based systems

Changes:
v2:
	- more descriptive commit body
v3:
	- made 'i2c_acpi_find_adapter_by_handle' static inline
v4:
	- don't initialize i2c_adapter to NULL. Instead see below...
	- handle the case of neither DT nor ACPI present as invalid.
	- alphabetical includes.
	- use has_acpi_companion().
	- use the same argument name in i2c_acpi_find_adapter_by_handle()
	  in both stubbed and non-stubbed cases.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/i2c/i2c-core-acpi.c

@@ -337,7 +337,7 @@ static int i2c_acpi_find_match_device(struct device *dev, void *data)
 	return ACPI_COMPANION(dev) == data;
 }
 
-static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
+struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 {
 	struct device *dev;
 
@@ -345,6 +345,7 @@ static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 			      i2c_acpi_find_match_adapter);
 	return dev ? i2c_verify_adapter(dev) : NULL;
 }
+EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 
 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 {

drivers/net/phy/sfp.c

 // SPDX-License-Identifier: GPL-2.0
+#include <linux/acpi.h>
 #include <linux/ctype.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
@@ -1782,6 +1783,7 @@ static void sfp_cleanup(void *data)
 static int sfp_probe(struct platform_device *pdev)
 {
 	const struct sff_data *sff;
+	struct i2c_adapter *i2c;
 	struct sfp *sfp;
 	bool poll = false;
 	int irq, err, i;
@@ -1801,7 +1803,6 @@ static int sfp_probe(struct platform_device *pdev)
 	if (pdev->dev.of_node) {
 		struct device_node *node = pdev->dev.of_node;
 		const struct of_device_id *id;
-		struct i2c_adapter *i2c;
 		struct device_node *np;
 
 		id = of_match_node(sfp_of_match, node);
@@ -1818,6 +1819,25 @@ static int sfp_probe(struct platform_device *pdev)
 
 		i2c = of_find_i2c_adapter_by_node(np);
 		of_node_put(np);
+	} else if (has_acpi_companion(&pdev->dev)) {
+		struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+		struct fwnode_handle *fw = acpi_fwnode_handle(adev);
+		struct fwnode_reference_args args;
+		struct acpi_handle *acpi_handle;
+		int ret;
+
+		ret = acpi_node_get_property_reference(fw, "i2c-bus", 0, &args);
+		if (ACPI_FAILURE(ret) || !is_acpi_device_node(args.fwnode)) {
+			dev_err(&pdev->dev, "missing 'i2c-bus' property\n");
+			return -ENODEV;
+		}
+
+		acpi_handle = ACPI_HANDLE_FWNODE(args.fwnode);
+		i2c = i2c_acpi_find_adapter_by_handle(acpi_handle);
+	} else {
+		return -EINVAL;
+	}
+
 	if (!i2c)
 		return -EPROBE_DEFER;
 
@@ -1826,7 +1846,6 @@ static int sfp_probe(struct platform_device *pdev)
 		i2c_put_adapter(i2c);
 		return err;
 	}
-	}
 
 	for (i = 0; i < GPIO_MAX; i++)
 		if (sff->gpios & BIT(i)) {

include/linux/i2c.h

@@ -14,6 +14,7 @@
 #ifndef _LINUX_I2C_H
 #define _LINUX_I2C_H
 
+#include <linux/acpi.h>		/* for acpi_handle */
 #include <linux/mod_devicetable.h>
 #include <linux/device.h>	/* for struct device */
 #include <linux/sched.h>	/* for completion */
@@ -981,6 +982,7 @@ bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
 u32 i2c_acpi_find_bus_speed(struct device *dev);
 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 				       struct i2c_board_info *info);
+struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
 #else
 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
 					     struct acpi_resource_i2c_serialbus **i2c)
@@ -996,6 +998,10 @@ static inline struct i2c_client *i2c_acpi_new_device(struct device *dev,
 {
 	return NULL;
 }
+static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
+{
+	return NULL;
+}
 #endif /* CONFIG_ACPI */
 
 #endif /* _LINUX_I2C_H */