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| author | Shecky Lin <sheckylin@chromium.org> | 2020-03-11 15:15:46 +0800 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2020-03-17 12:11:46 +0000 |
| commit | c6f631c3e461cdafe5b643fa5d12415d67097ac6 (patch) | |
| tree | 2df6ee9ff6f3da0353449dcfea21d3d3c38cdcfc /include/i2c_hid.h | |
| parent | e5e676f641dec32ddf4b32d1b8f4f9636e31ff2a (diff) | |
| download | chrome-ec-c6f631c3e461cdafe5b643fa5d12415d67097ac6.tar.gz | |
i2c_hid_touchpad: Add basic structs and descriptors
This is part of a chain to add a common I2C HID interface for
touchpads.
The CL layouts basic struct, defines and HID descriptors that
would be used by an I2C HID touchpad implementation.
BUG=chromium:1008568
BRANCH=none
TEST=Build and run on MCU to forward touchpad events to host
through I2C HID.
Change-Id: I89108f0cdce1a9a11bf1e26e43c6662959c7184e
Signed-off-by: Shecky Lin <sheckylin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2094927
Diffstat (limited to 'include/i2c_hid.h')
| -rw-r--r-- | include/i2c_hid.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/include/i2c_hid.h b/include/i2c_hid.h new file mode 100644 index 0000000000..8568b42837 --- /dev/null +++ b/include/i2c_hid.h @@ -0,0 +1,67 @@ +/* Copyright 2020 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +/* + * General definitions for I2C-HID + * + * For a complete reference, please see the following docs on + * https://docs.microsoft.com/ + * + * 1. hid-over-i2c-protocol-spec-v1-0.docx + */ +#ifndef __CROS_EC_I2C_HID_H +#define __CROS_EC_I2C_HID_H + +#include "common.h" +#include "stdint.h" + +/* + * I2C-HID registers + * + * Except for I2C_HID_HID_DESC_REGISTER, fields in this section can be chosen + * freely so we just picked something that we are happy with. + * + * I2C_HID_HID_DESC_REGISTER is defined in the ACPI table so please make sure + * you have put in the same value there. + */ +#define I2C_HID_HID_DESC_REGISTER 0x0001 +#define I2C_HID_REPORT_DESC_REGISTER 0x1000 +#define I2C_HID_INPUT_REPORT_REGISTER 0x2000 +#define I2C_HID_COMMAND_REGISTER 0x3000 +#define I2C_HID_DATA_REGISTER 0x3000 + +/* I2C-HID commands */ +#define I2C_HID_CMD_RESET 0x01 +#define I2C_HID_CMD_GET_REPORT 0x02 +#define I2C_HID_CMD_SET_REPORT 0x03 +#define I2C_HID_CMD_GET_IDLE 0x04 +#define I2C_HID_CMD_SET_IDLE 0x05 +#define I2C_HID_CMD_GET_PROTOCOL 0x06 +#define I2C_HID_CMD_SET_PROTOCOL 0x07 +#define I2C_HID_CMD_SET_POWER 0x08 + +/* Common HID fields */ +#define I2C_HID_DESC_LENGTH sizeof(struct i2c_hid_descriptor) +#define I2C_HID_BCD_VERSION 0x0100 + +/* I2C-HID HID descriptor */ +struct __packed i2c_hid_descriptor { + uint16_t wHIDDescLength; + uint16_t bcdVersion; + uint16_t wReportDescLength; + uint16_t wReportDescRegister; + uint16_t wInputRegister; + uint16_t wMaxInputLength; + uint16_t wOutputRegister; + uint16_t wMaxOutputLength; + uint16_t wCommandRegister; + uint16_t wDataRegister; + uint16_t wVendorID; + uint16_t wProductID; + uint16_t wVersionID; + uint32_t reserved; +}; + +#endif /* __CROS_EC_I2C_HID_H */ |