HID: hid-logitech-hidpp: Add range sysfs for Logitech G920

The G920 can adjust the amount of 'turn' it permits, this patch adds
a sysfs file 'range' to control this.

Signed-off-by: Simon Wood <simon@mungewell.org>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 139 insertions, 1 deletions

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 98b8f096d7ee..fc553e3f948d 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -1295,6 +1295,133 @@ static int k400_connect(struct hid_device *hdev, bool connected)
         return k400_disable_tap_to_click(hidpp);
 }
 
+/* ------------------------------------------------------------------------- */
+/* 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                                                      */
 /* -------------------------------------------------------------------------- */
@@ -1595,6 +1722,10 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
                 ret = k400_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);
@@ -1648,6 +1779,10 @@ 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 */
@@ -1673,6 +1808,7 @@ 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);
         }
@@ -1689,8 +1825,10 @@ 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);