[RFC 4/5] HID: hid-logitech-hidpp: Add range sysfs for Logitech G920

Simon Wood
2015-10-23T18:00:09Z

The G920 can adjust the amount of 'turn' it permits, this patch adds
a sysfs file 'range' to control this.
---
drivers/hid/hid-logitech-hidpp.c | 140 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 139 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 76d7267..db05f55 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -1170,6 +1170,133 @@ static int m560_input_mapping(struct hid_device *hdev, struct hid_input *hi,
return -1;
}

+/* ------------------------------------------------------------------------- */
+/* Logitech G920 Driving Force Racing Wheel for Xbox One */
+/* ------------------------------------------------------------------------- */
+
+#define HIDPP_PAGE_G920_FORCE_FEEDBACK 0x8123
+
+/* Using session ID = 1 */
+#define CMD_G920_FORCE_GET_APERTURE 0x51
+#define CMD_G920_FORCE_SET_APERTURE 0x61
+
+struct g920_private_data {
+ u8 force_feature;
+ u16 range;
+};
+
+#define to_hid_device(pdev) container_of(pdev, struct hid_device, dev)
+
+static ssize_t g920_range_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct hid_device *hid = to_hid_device(dev);
+ struct hidpp_device *hidpp = hid_get_drvdata(hid);
+ struct g920_private_data *pdata;
+
+ pdata = hidpp->private_data;
+ if (!pdata) {
+ hid_err(hid, "Private driver data not found!\n");
+ return -EINVAL;
+ }
+
+ return scnprintf(buf, PAGE_SIZE, "%u\n", pdata->range);
+}
+
+static ssize_t g920_range_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct hid_device *hid = to_hid_device(dev);
+ struct hidpp_device *hidpp = hid_get_drvdata(hid);
+ struct g920_private_data *pdata;
+ struct hidpp_report response;
+ u8 params[2];
+ int ret;
+ u16 range = simple_strtoul(buf, NULL, 10);
+
+ pdata = hidpp->private_data;
+ if (!pdata) {
+ hid_err(hid, "Private driver data not found!\n");
+ return -EINVAL;
+ }
+
+ if (range < 180)
+ range = 180;
+ else if (range > 900)
+ range = 900;
+
+ params[0] = range >> 8;
+ params[1] = range & 0x00FF;
+
+ ret = hidpp_send_fap_command_sync(hidpp, pdata->force_feature,
+ CMD_G920_FORCE_SET_APERTURE, params, 2, &response);
+ if (ret)
+ return ret;
+
+ pdata->range = range;
+ return count;
+}
+
+static DEVICE_ATTR(range, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, g920_range_show, g920_range_store);
+
+static int g920_allocate(struct hid_device *hdev)
+{
+ struct hidpp_device *hidpp = hid_get_drvdata(hdev);
+ struct g920_private_data *pdata;
+
+ pdata = devm_kzalloc(&hdev->dev, sizeof(struct g920_private_data),
+ GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ hidpp->private_data = pdata;
+
+ return 0;
+}
+
+static int g920_get_config(struct hidpp_device *hidpp)
+{
+ struct g920_private_data *pdata = hidpp->private_data;
+ struct hidpp_report response;
+ u8 feature_type;
+ u8 feature_index;
+ int ret;
+
+ pdata = hidpp->private_data;
+ if (!pdata) {
+ hid_err(hidpp->hid_dev, "Private driver data not found!\n");
+ return -EINVAL;
+ }
+
+ /* Find feature and store for later use */
+ ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_G920_FORCE_FEEDBACK,
+ &feature_index, &feature_type);
+ if (ret)
+ return ret;
+
+ pdata->force_feature = feature_index;
+
+ /* Read current Range */
+ ret = hidpp_send_fap_command_sync(hidpp, feature_index,
+ CMD_G920_FORCE_GET_APERTURE, NULL, 0, &response);
+ if (ret > 0) {
+ hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
+ __func__, ret);
+ return -EPROTO;
+ }
+ if (ret)
+ return ret;
+
+ pdata->range = get_unaligned_be16(&response.fap.params[0]);
+
+ /* Create sysfs interface */
+ ret = device_create_file(&(hidpp->hid_dev->dev), &dev_attr_range);
+ if (ret)
+ hid_warn(hidpp->hid_dev, "Unable to create sysfs interface for \"range\", errno %d\n", ret);
+
+ return 0;
+}
+
/* -------------------------------------------------------------------------- */
/* Generic HID++ devices */
/* -------------------------------------------------------------------------- */
@@ -1456,6 +1583,10 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
ret = m560_allocate(hdev);
if (ret)
goto allocate_fail;
+ } else if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
+ ret = g920_allocate(hdev);
+ if (ret)
+ goto allocate_fail;
}

INIT_WORK(&hidpp->work, delayed_work_cb);
@@ -1509,6 +1640,10 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
ret = wtp_get_config(hidpp);
if (ret)
goto hid_hw_open_failed;
+ } else if (connected && (hidpp->quirks & HIDPP_QUIRK_CLASS_G920)) {
+ ret = g920_get_config(hidpp);
+ if (ret)
+ goto hid_hw_open_failed;
}

/* Block incoming packets */
@@ -1534,6 +1669,7 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
hid_hw_open_failed:
hid_device_io_stop(hdev);
if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
+ device_remove_file(&hdev->dev, &dev_attr_range);
hid_hw_close(hdev);
hid_hw_stop(hdev);
}
@@ -1550,8 +1686,10 @@ static void hidpp_remove(struct hid_device *hdev)
{
struct hidpp_device *hidpp = hid_get_drvdata(hdev);

- if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920)
+ if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
+ device_remove_file(&hdev->dev, &dev_attr_range);
hid_hw_close(hdev);
+ }
hid_hw_stop(hdev);
cancel_work_sync(&hidpp->work);
mutex_destroy(&hidpp->send_mutex);
--
2.1.4