arduino-esp32/cores/esp32/esp32-hal-i2c.h
chuck todd b05430cfd9 Wire ReSTART fix, with others (#1717)
* ReSTART fix, Sequencing fix

pr #1665 introduce a problem with ReSTART, when solving this problem I found an interaction between the TxFifo refill, RxFifo empty and CMD[] fill.  during certain sequences a dataqueue command would be skipped, this skipping resulted in a mismatch between the contents of the TxFifo and the i2c command sequence.  The problem manifested as an ACK error. 
In addition to this required bug fix I propose:
* `Wire.begin()` be changed from a `void` to a `bool` this will allow the reset functionality of `Wire.begin()` to be reported.  Currently `Wire.begin()` attempts to reset the i2c Peripheral, but cannot report success/failure.
* `Wire.busy()` be added. this `bool` function returns the hardware status of the bus. This status can be use in multi-master environments for application level interleaving of commands, also in single master environment, it can be used to detect a 'hung' bus.  With the functional change to `Wire.begin()` this allows app level recover of a hung bus.
* `Wire.lastError()` value updated for all errors, previously when interleaving `Wire.endTransmission(false)` and `Wire.readTransmission(false)`, the 128 byte `Wire.write()` buffer was exhausted without generating and error(very exotic). I discovered this error when I created a sequence of directed reads to a EEPROM. Each directed read used 2 bytes of the 128 byte `write()` buffer, so after 64 consecutive ReSTART writes with ReSTART reads, `Wire()`  had no room to record the directed address bytes.  It generated just a NAK check without setting the EEPROMs internal register address.  The succeeding ReSTART read succeeded at incorrect address.
* Changes to the HAL layer:
** added `i2cGetStatus()` which returns the i2c peripheral status word, used to detect bus_busy currently
** added `i2cDebug()` programmatic control of debug buffer output
** changed `i2cAddQueue()` to allow data_only queue element this will allow a i2c transaction to use multiple data pointers.
** removed direct access to DumpInts(), DumpI2c() from app, use i2cDebug() to set trigger points 
 
*

* Update esp32-hal-i2c.c

* Update Wire.cpp

* ReSTART, Sequencing

pr #1665 introduce a problem with ReSTART, when solving this problem I found an interaction between the TxFifo refill, RxFifo empty and CMD[] fill.  during certain sequences a dataqueue command would be skipped, this skipping resulted in a mismatch between the contents of the TxFifo and the i2c command sequence.  The problem manifested as an ACK error. 
In addition to this required bug fix I propose:
* `Wire.begin()` be changed from a `void` to a `bool` this will allow the reset functionality of `Wire.begin()` to be reported.  Currently `Wire.begin()` attempts to reset the i2c Peripheral, but cannot report success/failure.
* `Wire.busy()` be added. this `bool` function returns the hardware status of the bus. This status can be use in multi-master environments for application level interleaving of commands, also in single master environment, it can be used to detect a 'hung' bus.  With the functional change to `Wire.begin()` this allows app level recover of a hung bus.
* `Wire.lastError()` value updated for all errors, previously when interleaving `Wire.endTransmission(false)` and `Wire.readTransmission(false)`, the 128 byte `Wire.write()` buffer was exhausted without generating and error(very exotic). I discovered this error when I created a sequence of directed reads to a EEPROM. Each directed read used 2 bytes of the 128 byte `write()` buffer, so after 64 consecutive ReSTART writes with ReSTART reads, `Wire()`  had no room to record the directed address bytes.  It generated just a NAK check without setting the EEPROMs internal register address.  The succeeding ReSTART read succeeded at incorrect address.
* Changes to the HAL layer:
** added `i2cGetStatus()` which returns the i2c peripheral status word, used to detect bus_busy currently
** added `i2cDebug()` programmatic control of debug buffer output
** changed `i2cAddQueue()` to allow data_only queue element this will allow a i2c transaction to use multiple data pointers.
** removed direct access to DumpInts(), DumpI2c() from app, use i2cDebug() to set trigger points 
 
*

* Forgot DebugFlags Return

@andriyadi found this, total brain fade on my part.
2018-08-14 11:51:15 +02:00

83 lines
3.0 KiB
C

// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// modified Nov 2017 by Chuck Todd <StickBreaker> to support Interrupt Driven I/O
#ifndef _ESP32_HAL_I2C_H_
#define _ESP32_HAL_I2C_H_
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <stdbool.h>
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
// External Wire.h equivalent error Codes
typedef enum {
I2C_ERROR_OK=0,
I2C_ERROR_DEV,
I2C_ERROR_ACK,
I2C_ERROR_TIMEOUT,
I2C_ERROR_BUS,
I2C_ERROR_BUSY,
I2C_ERROR_MEMORY,
I2C_ERROR_CONTINUE,
I2C_ERROR_NO_BEGIN
} i2c_err_t;
struct i2c_struct_t;
typedef struct i2c_struct_t i2c_t;
i2c_t * i2cInit(uint8_t i2c_num, int8_t sda, int8_t scl, uint32_t clk_speed);
void i2cRelease(i2c_t *i2c); // free ISR, Free DQ, Power off peripheral clock. Must call i2cInit() to recover
i2c_err_t i2cWrite(i2c_t * i2c, uint16_t address, uint8_t* buff, uint16_t size, bool sendStop, uint16_t timeOutMillis);
i2c_err_t i2cRead(i2c_t * i2c, uint16_t address, uint8_t* buff, uint16_t size, bool sendStop, uint16_t timeOutMillis, uint32_t *readCount);
i2c_err_t i2cFlush(i2c_t *i2c);
i2c_err_t i2cSetFrequency(i2c_t * i2c, uint32_t clk_speed);
uint32_t i2cGetFrequency(i2c_t * i2c);
uint32_t i2cGetStatus(i2c_t * i2c); // Status register of peripheral
//Functions below should be used only if well understood
//Might be deprecated and removed in future
i2c_err_t i2cAttachSCL(i2c_t * i2c, int8_t scl);
i2c_err_t i2cDetachSCL(i2c_t * i2c, int8_t scl);
i2c_err_t i2cAttachSDA(i2c_t * i2c, int8_t sda);
i2c_err_t i2cDetachSDA(i2c_t * i2c, int8_t sda);
//Stickbreakers ISR Support
i2c_err_t i2cProcQueue(i2c_t *i2c, uint32_t *readCount, uint16_t timeOutMillis);
i2c_err_t i2cAddQueueWrite(i2c_t *i2c, uint16_t i2cDeviceAddr, uint8_t *dataPtr, uint16_t dataLen, bool SendStop, EventGroupHandle_t event);
i2c_err_t i2cAddQueueRead(i2c_t *i2c, uint16_t i2cDeviceAddr, uint8_t *dataPtr, uint16_t dataLen, bool SendStop, EventGroupHandle_t event);
//stickbreaker debug support
uint32_t i2cDebug(i2c_t *, uint32_t setBits, uint32_t resetBits);
// Debug actions have 3 currently defined locus
// 0xXX------ : at entry of ProcQueue
// 0x--XX---- : at exit of ProcQueue
// 0x------XX : at entry of Flush
//
// bit 0 causes DumpI2c to execute
// bit 1 causes DumpInts to execute
// bit 2 causes DumpCmdqueue to execute
// bit 3 causes DumpStatus to execute
// bit 4 causes DumpFifo to execute
#ifdef __cplusplus
}
#endif
#endif /* _ESP32_HAL_I2C_H_ */