diff options
| -rw-r--r-- | Documentation/devicetree/bindings/hid/hid-over-i2c.txt | 28 | ||||
| -rw-r--r-- | drivers/hid/i2c-hid/i2c-hid.c | 44 | ||||
| -rw-r--r-- | include/linux/i2c/i2c-hid.h | 3 |
3 files changed, 73 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/hid/hid-over-i2c.txt b/Documentation/devicetree/bindings/hid/hid-over-i2c.txt new file mode 100644 index 000000000000..488edcb264c4 --- /dev/null +++ b/Documentation/devicetree/bindings/hid/hid-over-i2c.txt @@ -0,0 +1,28 @@ +* HID over I2C Device-Tree bindings + +HID over I2C provides support for various Human Interface Devices over the +I2C bus. These devices can be for example touchpads, keyboards, touch screens +or sensors. + +The specification has been written by Microsoft and is currently available here: +http://msdn.microsoft.com/en-us/library/windows/hardware/hh852380.aspx + +If this binding is used, the kernel module i2c-hid will handle the communication +with the device and the generic hid core layer will handle the protocol. + +Required properties: +- compatible: must be "hid-over-i2c" +- reg: i2c slave address +- hid-descr-addr: HID descriptor address +- interrupt-parent: the phandle for the interrupt controller +- interrupts: interrupt line + +Example: + + i2c-hid-dev@2c { + compatible = "hid-over-i2c"; + reg = <0x2c>; + hid-descr-addr = <0x0020>; + interrupt-parent = <&gpx3>; + interrupts = <3 2>; + }; diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c index 879b0ed701a3..fc9d92cb3f39 100644 --- a/drivers/hid/i2c-hid/i2c-hid.c +++ b/drivers/hid/i2c-hid/i2c-hid.c @@ -35,6 +35,7 @@ #include <linux/hid.h> #include <linux/mutex.h> #include <linux/acpi.h> +#include <linux/of.h> #include <linux/i2c/i2c-hid.h> @@ -933,6 +934,42 @@ static inline int i2c_hid_acpi_pdata(struct i2c_client *client, } #endif +#ifdef CONFIG_OF +static int i2c_hid_of_probe(struct i2c_client *client, + struct i2c_hid_platform_data *pdata) +{ + struct device *dev = &client->dev; + u32 val; + int ret; + + ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val); + if (ret) { + dev_err(&client->dev, "HID register address not provided\n"); + return -ENODEV; + } + if (val >> 16) { + dev_err(&client->dev, "Bad HID register address: 0x%08x\n", + val); + return -EINVAL; + } + pdata->hid_descriptor_address = val; + + return 0; +} + +static const struct of_device_id i2c_hid_of_match[] = { + { .compatible = "hid-over-i2c" }, + {}, +}; +MODULE_DEVICE_TABLE(of, i2c_hid_of_match); +#else +static inline int i2c_hid_of_probe(struct i2c_client *client, + struct i2c_hid_platform_data *pdata) +{ + return -ENODEV; +} +#endif + static int i2c_hid_probe(struct i2c_client *client, const struct i2c_device_id *dev_id) { @@ -954,7 +991,11 @@ static int i2c_hid_probe(struct i2c_client *client, if (!ihid) return -ENOMEM; - if (!platform_data) { + if (client->dev.of_node) { + ret = i2c_hid_of_probe(client, &ihid->pdata); + if (ret) + goto err; + } else if (!platform_data) { ret = i2c_hid_acpi_pdata(client, &ihid->pdata); if (ret) { dev_err(&client->dev, @@ -1095,6 +1136,7 @@ static struct i2c_driver i2c_hid_driver = { .owner = THIS_MODULE, .pm = &i2c_hid_pm, .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match), + .of_match_table = of_match_ptr(i2c_hid_of_match), }, .probe = i2c_hid_probe, diff --git a/include/linux/i2c/i2c-hid.h b/include/linux/i2c/i2c-hid.h index 60e411d764d4..7aa901d92058 100644 --- a/include/linux/i2c/i2c-hid.h +++ b/include/linux/i2c/i2c-hid.h @@ -19,7 +19,8 @@ * @hid_descriptor_address: i2c register where the HID descriptor is stored. * * Note that it is the responsibility of the platform driver (or the acpi 5.0 - * driver) to setup the irq related to the gpio in the struct i2c_board_info. + * driver, or the flattened device tree) to setup the irq related to the gpio in + * the struct i2c_board_info. * The platform driver should also setup the gpio according to the device: * * A typical example is the following: |