diff options
Diffstat (limited to 'drivers/hid')
| -rw-r--r-- | drivers/hid/i2c-hid/i2c-hid.c | 45 |
1 files changed, 13 insertions, 32 deletions
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c index b50860db92f1..21aafc8f48c8 100644 --- a/drivers/hid/i2c-hid/i2c-hid.c +++ b/drivers/hid/i2c-hid/i2c-hid.c @@ -807,34 +807,18 @@ static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) unsigned int dsize; int ret; - /* Fetch the length of HID description, retrieve the 4 first bytes: - * bytes 0-1 -> length - * bytes 2-3 -> bcdVersion (has to be 1.00) */ - ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, 4); - - i2c_hid_dbg(ihid, "%s, ihid->hdesc_buffer: %4ph\n", __func__, - ihid->hdesc_buffer); - + /* i2c hid fetch using a fixed descriptor size (30 bytes) */ + i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); + ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, + sizeof(struct i2c_hid_desc)); if (ret) { - dev_err(&client->dev, - "unable to fetch the size of HID descriptor (ret=%d)\n", - ret); - return -ENODEV; - } - - dsize = le16_to_cpu(hdesc->wHIDDescLength); - /* - * the size of the HID descriptor should at least contain - * its size and the bcdVersion (4 bytes), and should not be greater - * than sizeof(struct i2c_hid_desc) as we directly fill this struct - * through i2c_hid_command. - */ - if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) { - dev_err(&client->dev, "weird size of HID descriptor (%u)\n", - dsize); + dev_err(&client->dev, "hid_descr_cmd failed\n"); return -ENODEV; } + /* Validate the length of HID descriptor, the 4 first bytes: + * bytes 0-1 -> length + * bytes 2-3 -> bcdVersion (has to be 1.00) */ /* check bcdVersion == 1.0 */ if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { dev_err(&client->dev, @@ -843,17 +827,14 @@ static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) return -ENODEV; } - i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); - - ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, - dsize); - if (ret) { - dev_err(&client->dev, "hid_descr_cmd Fail\n"); + /* Descriptor length should be 30 bytes as per the specification */ + dsize = le16_to_cpu(hdesc->wHIDDescLength); + if (dsize != sizeof(struct i2c_hid_desc)) { + dev_err(&client->dev, "weird size of HID descriptor (%u)\n", + dsize); return -ENODEV; } - i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer); - return 0; } |