[PATCH v2 1/3] i2c: core: Allow getting acpi info by index

[PATCH v2 1/3] i2c: core: Allow getting acpi info by index

[Hans de Goede]

Modify struct i2c_acpi_lookup and i2c_acpi_fill_info() to allow
using them to get the info from a certain index in the acpi-resource
list rather then taking the first I2cSerialBus resource.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/i2c/i2c-core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index d2402bb..32b58fb 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -112,6 +112,8 @@ struct i2c_acpi_lookup {
 	acpi_handle adapter_handle;
 	acpi_handle device_handle;
 	acpi_handle search_handle;
+	int n;
+	int index;
 	u32 speed;
 	u32 min_speed;
 };
@@ -123,6 +125,9 @@ static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
 	struct acpi_resource_i2c_serialbus *sb;
 	acpi_status status;
 
+	if (lookup->index != -1 && lookup->n++ != lookup->index)
+		return 1;
+
 	if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
 		return 1;
 
@@ -182,6 +187,7 @@ static int i2c_acpi_get_info(struct acpi_device *adev,
 
 	memset(&lookup, 0, sizeof(lookup));
 	lookup.info = info;
+	lookup.index = -1;
 
 	ret = i2c_acpi_do_lookup(adev, &lookup);
 	if (ret)
@@ -328,6 +334,7 @@ u32 i2c_acpi_find_bus_speed(struct device *dev)
 	lookup.search_handle = ACPI_HANDLE(dev);
 	lookup.min_speed = UINT_MAX;
 	lookup.info = &dummy;
+	lookup.index = -1;
 
 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 				     I2C_ACPI_MAX_SCAN_DEPTH,
-- 
2.9.3

[PATCH v2 2/3] i2c: core: Add new i2c_acpi_new_device helper function

[Hans de Goede]

By default the i2c subsys creates an i2c-client for the first I2cSerialBus
resource of an acpi_device, but some acpi_devices have multiple
I2cSerialBus resources and the driver may need access to the others.

This commit adds a new i2c_acpi_new_device function which can be used by
drivers to create an i2c-client for any (other) I2cSerialBus resource of
an acpi_device.

Note that the other resources may even be on a different i2c bus, so just
retrieving the client address is not enough.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/i2c/i2c-core.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/i2c.h    |  5 +++++
 2 files changed, 53 insertions(+)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 32b58fb..8ddd55b 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -421,6 +421,54 @@ static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 static struct notifier_block i2c_acpi_notifier = {
 	.notifier_call = i2c_acpi_notify,
 };
+
+/**
+ * i2c_acpi_new_device - Create i2c client for the Nth acpi resource of dev
+ * @dev:     Device owning the acpi resources to get the client from
+ * @index:   Index of acpi resource to get 
+ *
+ * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
+ * resource of an acpi_device, but some acpi_devices have multiple
+ * I2cSerialBus resources and the driver may need access to the others.
+ * This function can be used by drivers to create an i2c-client for any
+ * resource of an acpi_device.
+ *
+ * Returns a pointer to the new i2c-client, or NULL if the resource or
+ * adapter were not found.
+ */
+struct i2c_client *i2c_acpi_new_device(struct device *dev, int index)
+{
+	struct i2c_acpi_lookup lookup;
+	struct i2c_board_info info;
+	struct i2c_adapter *adapter;
+	struct acpi_device *adev;
+	LIST_HEAD(resource_list);
+	int ret;
+
+	adev = ACPI_COMPANION(dev);
+	if (!adev)
+		return NULL;
+
+	memset(&info, 0, sizeof(info));
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.info = &info;
+	lookup.device_handle = acpi_device_handle(adev);
+	lookup.index = index;
+
+	ret = acpi_dev_get_resources(adev, &resource_list,
+				     i2c_acpi_fill_info, &lookup);
+	acpi_dev_free_resource_list(&resource_list);
+
+	if (ret < 0 || !info.addr)
+		return NULL;
+
+	adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
+	if (!adapter)
+		return NULL;
+
+	return i2c_new_device(adapter, &info);
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
 #else /* CONFIG_ACPI */
 static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
 extern struct notifier_block i2c_acpi_notifier;
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 6b18352..369ebfa 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -824,11 +824,16 @@ static inline const struct of_device_id
 
 #if IS_ENABLED(CONFIG_ACPI)
 u32 i2c_acpi_find_bus_speed(struct device *dev);
+struct i2c_client *i2c_acpi_new_device(struct device *dev, int index);
 #else
 static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
 {
 	return 0;
 }
+static inline struct i2c_client *i2c_acpi_new_device(struct device *d, int i)
+{
+	return NULL;
+}
 #endif /* CONFIG_ACPI */
 
 #endif /* _LINUX_I2C_H */
-- 
2.9.3

[PATCH v2 3/3] i2c: core: Allow drivers to specify index for irq to get from of / acpi

[Hans de Goede]

Some of or acpi declared / enumerated devices may have multiple irq
resources declared and the driver may want to use a different irq then
the one with index 0.

This commit adds a new irq_index field to struct i2c_driver and makes
the i2c-core pass this to of_irq_get / acpi_dev_gpio_irq_get.

This is esp. useful for acpi declared devices where the irq with
index 0 may be entirely useless and cause i2c_device_probe to fail with
-EPROBE_DEFER.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
-Actually also use the irq_index for of interrupts
---
 drivers/i2c/i2c-core.c | 8 ++++++--
 include/linux/i2c.h    | 3 +++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 8ddd55b..f016278 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -984,6 +984,8 @@ static int i2c_device_probe(struct device *dev)
 	if (!client)
 		return 0;
 
+	driver = to_i2c_driver(dev->driver);
+
 	if (!client->irq) {
 		int irq = -ENOENT;
 
@@ -993,9 +995,11 @@ static int i2c_device_probe(struct device *dev)
 		} else if (dev->of_node) {
 			irq = of_irq_get_byname(dev->of_node, "irq");
 			if (irq == -EINVAL || irq == -ENODATA)
-				irq = of_irq_get(dev->of_node, 0);
+				irq = of_irq_get(dev->of_node,
+						 driver->irq_index);
 		} else if (ACPI_COMPANION(dev)) {
-			irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
+			irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev),
+						    driver->irq_index);
 		}
 		if (irq == -EPROBE_DEFER)
 			return irq;
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 369ebfa..a5ffe29 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -212,6 +212,9 @@ struct i2c_driver {
 	int (*detect)(struct i2c_client *, struct i2c_board_info *);
 	const unsigned short *address_list;
 	struct list_head clients;
+
+	/* IRQ index for retreiving irq from ACPI resources */
+	int irq_index;
 };
 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
 
-- 
2.9.3