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/* Copyright 2016 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.
*/
#include "consumer.h"
#include "producer.h"
#include "registers.h"
#include "task.h"
#include "usb_descriptor.h"
#include "util.h"
#ifndef __CROS_USB_I2C_H
#define __CROS_USB_I2C_H
/*
* Command:
* +----------+-----------+---------------+---------------+---------------+
* | port: 1B | addr: 1B | wr count : 1B | rd count : 1B | data : <= 60B |
* +----------+-----------+---------------+---------------+---------------+
*
* port address: 1 byte, i2c interface index
*
* slave address: 1 byte, i2c 7-bit bus address
*
* write count: 1 byte, zero based count of bytes to write
*
* read count: 1 byte, zero based count of bytes to read
*
* data: write payload up to 60 bytes of data to write,
* length must match write count
*
* Response:
* +-------------+---+---+-----------------------+
* | status : 2B | 0 | 0 | read payload : <= 60B |
* +-------------+---+---+-----------------------+
*
* status: 2 byte status
* 0x0000: Success
* 0x0001: I2C timeout
* 0x0002: Busy, try again
* This can happen if someone else has acquired the shared memory
* buffer that the I2C driver uses as /dev/null
* 0x0003: Write count invalid (> 60 bytes, or mismatch with payload)
* 0x0004: Read count invalid (> 60 bytes)
* 0x0005: The port specified is invalid.
* 0x8000: Unknown error mask
* The bottom 15 bits will contain the bottom 15 bits from the EC
* error code.
*
* read payload: up to 60 bytes of data read from I2C, length will match
* requested read count
*/
enum usb_i2c_error {
USB_I2C_SUCCESS = 0x0000,
USB_I2C_TIMEOUT = 0x0001,
USB_I2C_BUSY = 0x0002,
USB_I2C_WRITE_COUNT_INVALID = 0x0003,
USB_I2C_READ_COUNT_INVALID = 0x0004,
USB_I2C_PORT_INVALID = 0x0005,
USB_I2C_UNKNOWN_ERROR = 0x8000,
};
#define USB_I2C_MAX_WRITE_COUNT 60
#define USB_I2C_MAX_READ_COUNT 60
BUILD_ASSERT(USB_MAX_PACKET_SIZE == (1 + 1 + 1 + 1 + USB_I2C_MAX_WRITE_COUNT));
BUILD_ASSERT(USB_MAX_PACKET_SIZE == (2 + 1 + 1 + USB_I2C_MAX_READ_COUNT));
/*
* Compile time Per-USB gpio configuration stored in flash. Instances of this
* structure are provided by the user of the USB i2c. This structure binds
* together all information required to operate a USB i2c.
*/
struct usb_i2c_config {
uint16_t *buffer;
/* Deferred function to call to handle SPI request. */
const struct deferred_data *deferred;
struct consumer const consumer;
struct queue const *tx_queue;
};
extern struct consumer_ops const usb_i2c_consumer_ops;
/*
* Convenience macro for defining a USB I2C bridge driver.
*
* NAME is used to construct the names of the trampoline functions and the
* usb_i2c_config struct, the latter is just called NAME.
*
* INTERFACE is the index of the USB interface to associate with this
* I2C driver.
*
* INTERFACE_NAME is the index of the USB string descriptor (iInterface).
*
* ENDPOINT is the index of the USB bulk endpoint used for receiving and
* transmitting bytes.
*/
#define USB_I2C_CONFIG(NAME, \
INTERFACE, \
INTERFACE_NAME, \
ENDPOINT) \
static uint16_t \
CONCAT2(NAME, _buffer_)[USB_MAX_PACKET_SIZE/2]; \
static void CONCAT2(NAME, _deferred_)(void); \
DECLARE_DEFERRED(CONCAT2(NAME, _deferred_)); \
static struct queue const CONCAT2(NAME, _to_usb_); \
static struct queue const CONCAT3(usb_to_, NAME, _); \
USB_STREAM_CONFIG_FULL(CONCAT2(NAME, _usb_), \
INTERFACE, \
USB_CLASS_VENDOR_SPEC, \
USB_SUBCLASS_GOOGLE_I2C, \
USB_PROTOCOL_GOOGLE_I2C, \
INTERFACE_NAME, \
ENDPOINT, \
USB_MAX_PACKET_SIZE, \
USB_MAX_PACKET_SIZE, \
CONCAT3(usb_to_, NAME, _), \
CONCAT2(NAME, _to_usb_)) \
struct usb_i2c_config const NAME = { \
.buffer = CONCAT2(NAME, _buffer_), \
.deferred = &CONCAT2(NAME, _deferred__data), \
.consumer = { \
.queue = &CONCAT3(usb_to_, NAME, _), \
.ops = &usb_i2c_consumer_ops, \
}, \
.tx_queue = &CONCAT2(NAME, _to_usb_), \
}; \
static struct queue const CONCAT2(NAME, _to_usb_) = \
QUEUE_DIRECT(USB_MAX_PACKET_SIZE, uint8_t, \
null_producer, CONCAT2(NAME, _usb_).consumer); \
static struct queue const CONCAT3(usb_to_, NAME, _) = \
QUEUE_DIRECT(USB_MAX_PACKET_SIZE, uint8_t, \
CONCAT2(NAME, _usb_).producer, NAME.consumer); \
static void CONCAT2(NAME, _deferred_)(void) \
{ usb_i2c_deferred(&NAME); }
/*
* Handle I2C request in a deferred callback.
*/
void usb_i2c_deferred(struct usb_i2c_config const *config);
/*
* These functions should be implemented by the board to provide any board
* specific operations required to enable or disable access to the I2C device.
*/
int usb_i2c_board_enable(void);
void usb_i2c_board_disable(int debounce);
#endif /* __CROS_USB_I2C_H */
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