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authorBenjamin Tissoires <benjamin.tissoires@redhat.com>2013-06-13 09:50:35 +0200
committerJiri Kosina <jkosina@suse.cz>2013-07-31 12:10:31 +0200
commit3d7d248cf484fe37595698e0ca31a9bcecc85a42 (patch)
tree33b668ffdf0409e3efda2b6f12a3ffe1e57aa87b
parent3366dd9fa887ebbda4872e9554f853eaeda764be (diff)
HID: i2c-hid: add DT bindings
Add device tree based support for HID over I2C devices. Tested on an Odroid-X board with a Synaptics touchpad. Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
-rw-r--r--Documentation/devicetree/bindings/hid/hid-over-i2c.txt28
-rw-r--r--drivers/hid/i2c-hid/i2c-hid.c44
-rw-r--r--include/linux/i2c/i2c-hid.h3
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 00000000000..488edcb264c
--- /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 879b0ed701a..fc9d92cb3f3 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 60e411d764d..7aa901d9205 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: