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.
Here is an example DSDT excerpt from such a device:
Device (WIDR)
{
Name (_HID, "INT33FE" /* XPOWER Battery Device */)
Name (_CID, "INT33FE" /* XPOWER Battery Device */)
Name (_DDN, "WC PMIC Battery Device")
<snip>
Name (RBUF, ResourceTemplate ()
{
I2cSerialBusV2 (0x005E, ControllerInitiated, 0x000186A0,
AddressingMode7Bit, "\\_SB.PCI0.I2C7",
0x00, ResourceConsumer, , Exclusive,
)
I2cSerialBusV2 (0x0036, ControllerInitiated, 0x000186A0,
AddressingMode7Bit, "\\_SB.PCI0.I2C1",
0x00, ResourceConsumer, , Exclusive,
)
I2cSerialBusV2 (0x0022, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.PCI0.I2C1",
0x00, ResourceConsumer, , Exclusive,
)
I2cSerialBusV2 (0x0054, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.PCI0.I2C1",
0x00, ResourceConsumer, , Exclusive,
)
GpioInt (Level, ActiveLow, Exclusive, PullNone, 0x0000,
"\\_SB.PCI0.I2C7.PMI5", 0x00, ResourceConsumer, ,
)
{ // Pin list
0x0012
}
GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullNone, 0x0000,
"\\_SB.GPO1", 0x00, ResourceConsumer, ,
)
{ // Pin list
0x0005
}
GpioInt (Level, ActiveLow, Exclusive, PullNone, 0x0000,
"\\_SB.PCI0.I2C7.PMI5", 0x00, ResourceConsumer, ,
)
{ // Pin list
0x0013
}
})
Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings
{
Return (RBUF) /* \_SB_.PCI0.I2C7.WIDR.RBUF */
}
<snip>
}
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
Changes in v2:
-No changes
Changes in v3:
Added example DSDT snippet to the commit msg
---
drivers/i2c/i2c-core.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/i2c.h | 5 +++++
2 files changed, 52 insertions(+)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index f7faa99..062b480 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -421,6 +421,53 @@ 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 I2cSerialBus resource
+ * @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 other
+ * I2cSerialBus resources in the Current Resource Settings table.
+ *
+ * Returns a pointer to the new i2c-client, or NULL if the adapter is 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
--
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