From 19588bee0ea569bd6cc6bea5b284c34f1f526a59 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 11 Jul 2018 12:38:34 +0200 Subject: [PATCH] HID: elan: Query resolution from the touchpad Query the resolution from the touchpad and report it to userspace Signed-off-by: Hans de Goede Signed-off-by: Jiri Kosina --- drivers/hid/hid-elan.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/hid/hid-elan.c b/drivers/hid/hid-elan.c index d696b57..6969fb5 100644 --- a/drivers/hid/hid-elan.c +++ b/drivers/hid/hid-elan.c @@ -43,6 +43,8 @@ struct elan_drvdata { u8 mute_led_state; u16 max_x; u16 max_y; + u16 res_x; + u16 res_y; }; static int is_not_elan_touchpad(struct hid_device *hdev) @@ -97,6 +99,15 @@ static int elan_get_device_param(struct hid_device *hdev, return 0; } +static unsigned int elan_convert_res(char val) +{ + /* + * (value from firmware) * 10 + 790 = dpi + * dpi * 10 / 254 = dots/mm + */ + return (val * 10 + 790) * 10 / 254; +} + static int elan_get_device_params(struct hid_device *hdev) { struct elan_drvdata *drvdata = hid_get_drvdata(hdev); @@ -119,6 +130,13 @@ static int elan_get_device_params(struct hid_device *hdev) drvdata->max_y = (dmabuf[4] << 8) | dmabuf[3]; + ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_RES); + if (ret) + goto err; + + drvdata->res_x = elan_convert_res(dmabuf[3]); + drvdata->res_y = elan_convert_res(dmabuf[4]); + err: kfree(dmabuf); return ret; @@ -166,6 +184,9 @@ static int elan_input_configured(struct hid_device *hdev, struct hid_input *hi) return ret; } + input_abs_set_res(input, ABS_X, drvdata->res_x); + input_abs_set_res(input, ABS_Y, drvdata->res_y); + ret = input_register_device(input); if (ret) { hid_err(hdev, "Failed to register elan input device: %d\n", -- 2.7.4