I2c optimization and features (#321)
* custom delay * Update comment * add bus control status, add some missing include & fixed display output on sh1104 (#319) * add some missing include * Fixed display on SH1106 * Fix comment, add force sytem, rework flag, 16 bits data transfert * Update all library with new I2C API * custom delay * Update comment, add bus control status * fix i2c read + fix ds3231 temp + fix ssd1306 send
This commit is contained in:
Zaltora
Ruslan V. Uss
parent
1575bac0c7
commit
813477aa8a
19 changed files with 418 additions and 335 deletions
185
extras/i2c/i2c.c
185
extras/i2c/i2c.c
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@ -24,24 +24,35 @@
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#include <esp8266.h>
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#include <espressif/esp_misc.h> // sdk_os_delay_us
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#include <espressif/esp_system.h>
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#include "i2c.h"
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//#define I2C_DEBUG true
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// I2C driver for ESP8266 written for use with esp-open-rtos
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// Based on https://en.wikipedia.org/wiki/I²C#Example_of_bit-banging_the_I.C2.B2C_Master_protocol
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// With calling overhead, we end up at ~100kbit/s
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#define CLK_HALF_PERIOD_US (1)
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#ifdef I2C_DEBUG
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#define debug(fmt, ...) printf("%s: " fmt "\n", "I2C", ## __VA_ARGS__)
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#else
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#define debug(fmt, ...)
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#endif
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#define CLK_STRETCH (10)
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static bool started;
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static bool flag;
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static bool force;
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static uint8_t freq ;
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static uint8_t g_scl_pin;
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static uint8_t g_sda_pin;
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inline bool i2c_status(void)
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{
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return started;
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}
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void i2c_init(uint8_t scl_pin, uint8_t sda_pin)
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{
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started = false;
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flag = false ;
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g_scl_pin = scl_pin;
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g_sda_pin = sda_pin;
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@ -55,11 +66,33 @@ void i2c_init(uint8_t scl_pin, uint8_t sda_pin)
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// I2C bus idle state.
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gpio_write(g_scl_pin, 1);
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gpio_write(g_sda_pin, 1);
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// Prevent user, if frequency is high
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if (sdk_system_get_cpu_freq() == SYS_CPU_80MHZ)
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if (I2C_CUSTOM_DELAY_80MHZ == 1)
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debug("Max frequency is 320Khz at 80MHz");
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}
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static inline void i2c_delay(void)
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{
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sdk_os_delay_us(CLK_HALF_PERIOD_US);
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uint32_t delay;
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if (freq == SYS_CPU_160MHZ)
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{
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__asm volatile (
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"movi %0, %1" "\n"
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"1: addi %0, %0, -1" "\n"
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"bnez %0, 1b" "\n"
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: "=a" (delay) : "i" (I2C_CUSTOM_DELAY_160MHZ));
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}
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else
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{
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__asm volatile (
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"movi %0, %1" "\n"
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"1: addi %0, %0, -1" "\n"
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"bnez %0, 1b" "\n"
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: "=a" (delay) : "i" (I2C_CUSTOM_DELAY_80MHZ));
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}
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}
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// Set SCL as input, allowing it to float high, and return current
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@ -96,6 +129,7 @@ static inline void clear_sda(void)
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void i2c_start(void)
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{
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uint32_t clk_stretch = CLK_STRETCH;
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freq = sdk_system_get_cpu_freq();
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if (started) { // if started, do a restart cond
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// Set SDA to 1
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(void) read_sda();
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@ -104,18 +138,18 @@ void i2c_start(void)
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// Repeated start setup time, minimum 4.7us
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i2c_delay();
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}
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started = true;
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if (read_sda() == 0) {
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printf("I2C: arbitration lost in i2c_start\n");
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debug("arbitration lost in i2c_start");
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}
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// SCL is high, set SDA from 1 to 0.
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clear_sda();
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i2c_delay();
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clear_scl();
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started = true;
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}
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// Output stop condition
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void i2c_stop(void)
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bool i2c_stop(void)
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{
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uint32_t clk_stretch = CLK_STRETCH;
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// Set SDA to 0
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@ -127,10 +161,15 @@ void i2c_stop(void)
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i2c_delay();
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// SCL is high, set SDA from 0 to 1
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if (read_sda() == 0) {
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printf("I2C: arbitration lost in i2c_stop\n");
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debug("arbitration lost in i2c_stop");
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}
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i2c_delay();
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if (!started) {
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debug("link was break!");
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return false ; //If bus was stop in other way, the current transmission Failed
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}
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started = false;
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return true;
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}
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// Write a bit to I2C bus
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@ -148,7 +187,7 @@ static void i2c_write_bit(bool bit)
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// SCL is high, now data is valid
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// If SDA is high, check that nobody else is driving SDA
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if (bit && read_sda() == 0) {
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printf("I2C: arbitration lost in i2c_write_bit\n");
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debug("arbitration lost in i2c_write_bit");
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}
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i2c_delay();
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clear_scl();
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@ -194,47 +233,95 @@ uint8_t i2c_read(bool ack)
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return byte;
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}
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bool i2c_slave_write(uint8_t slave_addr, uint8_t *data, uint8_t len)
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void i2c_force_bus(bool state)
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{
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bool success = false;
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do {
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i2c_start();
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if (!i2c_write(slave_addr << 1))
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break;
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while (len--) {
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if (!i2c_write(*data++))
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break;
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}
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i2c_stop();
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success = true;
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} while(0);
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return success;
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force = state ;
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}
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bool i2c_slave_read(uint8_t slave_addr, uint8_t data, uint8_t *buf, uint32_t len)
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static int i2c_bus_test()
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{
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bool success = false;
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do {
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i2c_start();
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if (!i2c_write(slave_addr << 1)) {
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break;
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}
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i2c_write(data);
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i2c_stop();
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i2c_start();
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if (!i2c_write(slave_addr << 1 | 1)) { // Slave address + read
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break;
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}
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while(len) {
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*buf = i2c_read(len == 1);
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buf++;
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len--;
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}
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success = true;
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} while(0);
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i2c_stop();
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if (!success) {
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printf("I2C: write error\n");
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taskENTER_CRITICAL(); // To prevent task swaping after checking flag and before set it!
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bool status = flag ; // get current status
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if(force)
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{
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flag = true ; // force bus on
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taskEXIT_CRITICAL();
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if(status)
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i2c_stop(); //Bus was busy, stop it.
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}
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return success;
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else
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{
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if (status)
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{
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taskEXIT_CRITICAL();
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debug("busy");
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taskYIELD(); // If bus busy, change task to try finish last com.
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return -EBUSY ; // If bus busy, inform user
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}
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else
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{
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flag = true ; // Set Bus busy
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taskEXIT_CRITICAL();
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}
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}
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return 0 ;
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}
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int i2c_slave_write(uint8_t slave_addr, const uint8_t *data, const uint8_t *buf, uint32_t len)
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{
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if(i2c_bus_test())
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return -EBUSY ;
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i2c_start();
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if (!i2c_write(slave_addr << 1))
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goto error;
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if(data != NULL)
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if (!i2c_write(*data))
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goto error;
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while (len--) {
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if (!i2c_write(*buf++))
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goto error;
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}
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if (!i2c_stop())
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goto error;
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flag = false ; // Bus free
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return 0;
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error:
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debug("Write Error");
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i2c_stop();
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flag = false ; // Bus free
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return -EIO;
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}
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int i2c_slave_read(uint8_t slave_addr, const uint8_t *data, uint8_t *buf, uint32_t len)
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{
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if(i2c_bus_test())
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return -EBUSY ;
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if(data != NULL) {
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i2c_start();
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if (!i2c_write(slave_addr << 1))
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goto error;
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if (!i2c_write(*data))
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goto error;
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if (!i2c_stop())
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goto error;
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}
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i2c_start();
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if (!i2c_write(slave_addr << 1 | 1)) // Slave address + read
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goto error;
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while(len) {
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*buf = i2c_read(len == 1);
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buf++;
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len--;
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}
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if (!i2c_stop())
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goto error;
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flag = false ; // Bus free
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return 0;
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error:
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debug("Read Error");
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i2c_stop();
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flag = false ; // Bus free
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return -EIO;
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}
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103
extras/i2c/i2c.h
103
extras/i2c/i2c.h
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@ -27,31 +27,108 @@
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#include <stdint.h>
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#include <stdbool.h>
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#include <errno.h>
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#include <FreeRTOS.h>
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#include <task.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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// Init bitbanging I2C driver on given pins
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#define I2C_FREQUENCY_400K true // for test WIP
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/*
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* Some bit can be transmit slower.
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* Selected frequency fix the speed of a bit transmission
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* I2C lib take the maximum frequency defined
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* Don't change frequency when I2C transaction had begin
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*/
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#ifdef I2C_FREQUENCY_500K
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#define I2C_CUSTOM_DELAY_160MHZ 6
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#define I2C_CUSTOM_DELAY_80MHZ 1 //Sry, maximum is 320kHz at 80MHz
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#elif defined(I2C_FREQUENCY_400K)
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#define I2C_CUSTOM_DELAY_160MHZ 10
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#define I2C_CUSTOM_DELAY_80MHZ 1 //Sry, maximum is 320kHz at 80MHz
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#else
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#define I2C_CUSTOM_DELAY_160MHZ 100
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#define I2C_CUSTOM_DELAY_80MHZ 20
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#endif
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// I2C driver for ESP8266 written for use with esp-open-rtos
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// Based on https://en.wikipedia.org/wiki/I²C#Example_of_bit-banging_the_I.C2.B2C_Master_protocol
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// With calling overhead, we end up at ~320kbit/s
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//Level 0 API
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/**
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* Init bitbanging I2C driver on given pins
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* @param scl_pin SCL pin for I2C
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* @param sda_pin SDA pin for I2C
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*/
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void i2c_init(uint8_t scl_pin, uint8_t sda_pin);
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// Write a byte to I2C bus. Return true if slave acked.
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/**
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* Write a byte to I2C bus.
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* @param byte Pointer to device descriptor
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* @return true if slave acked
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*/
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bool i2c_write(uint8_t byte);
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// Read a byte from I2C bus. Return true if slave acked.
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/**
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* Read a byte from I2C bus.
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* @param ack Set Ack for slave (false: Ack // true: NoAck)
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* @return byte read from slave.
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*/
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uint8_t i2c_read(bool ack);
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// Write 'len' bytes from 'buf' to slave. Return true if slave acked.
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bool i2c_slave_write(uint8_t slave_addr, uint8_t *buf, uint8_t len);
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// Issue a read operation and send 'data', followed by reading 'len' bytes
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// from slave into 'buf'. Return true if slave acked.
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bool i2c_slave_read(uint8_t slave_addr, uint8_t data, uint8_t *buf, uint32_t len);
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// Send start and stop conditions. Only needed when implementing protocols for
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// devices where the i2c_slave_[read|write] functions above are of no use.
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/**
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* Send start or restart condition
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*/
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void i2c_start(void);
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void i2c_stop(void);
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/**
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* Send stop condition
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* @return false if link was broken
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*/
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bool i2c_stop(void);
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/**
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* get status from I2C bus.
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* @return true if busy.
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*/
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bool i2c_status(void);
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//Level 1 API (Don't need functions above)
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/**
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* This function will allow you to force a transmission I2C, cancel current transmission.
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* Warning: Use with precaution. Don't use it if you can avoid it. Usefull for priority transmission.
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* @param state Force the next I2C transmission if true (Use with precaution)
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*/
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void i2c_force_bus(bool state);
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/**
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* Write 'len' bytes from 'buf' to slave at 'data' register adress .
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* @param slave_addr slave device address
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* @param data Pointer to register address to send if non-null
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* @param buf Pointer to data buffer
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* @param len Number of byte to send
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* @return Non-Zero if error occured
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*/
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int i2c_slave_write(uint8_t slave_addr, const uint8_t *data, const uint8_t *buf, uint32_t len);
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/**
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* Issue a send operation of 'data' register adress, followed by reading 'len' bytes
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* from slave into 'buf'.
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* @param slave_addr slave device address
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* @param data Pointer to register address to send if non-null
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* @param buf Pointer to data buffer
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* @param len Number of byte to read
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* @return Non-Zero if error occured
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*/
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int i2c_slave_read(uint8_t slave_addr, const uint8_t *data, uint8_t *buf, uint32_t len);
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#ifdef __cplusplus
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}
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