WIP+ fix comment, add force sytem, rework flag, 16 bits data transfert

extras/i2c/i2c.c

@@ -38,17 +38,19 @@
 #define CLK_STRETCH  (10)
 
 static bool started;
+static bool flag;
 static uint8_t g_scl_pin;
 static uint8_t g_sda_pin;
 
 inline bool i2c_status(void)
 {
-    return started;
+    return flag;
 }
 
 void i2c_init(uint8_t scl_pin, uint8_t sda_pin)
 {
     started = false;
+    flag = false ;
     g_scl_pin = scl_pin;
     g_sda_pin = sda_pin;
 
@@ -62,17 +64,32 @@ void i2c_init(uint8_t scl_pin, uint8_t sda_pin)
     // I2C bus idle state.
     gpio_write(g_scl_pin, 1);
     gpio_write(g_sda_pin, 1);
+
+    // Prevent user, if frequency is high
+    if (sdk_system_get_cpu_freq() == SYS_CPU_80MHZ)
+        if (I2C_CUSTOM_DELAY_80MHZ == 1)
+            debug("Max frequency is 320Khz at 80MHz");
+
 }
 
 static inline void i2c_delay(void)
 {
+    uint32_t delay;
     if (sdk_system_get_cpu_freq() == SYS_CPU_160MHZ)
     {
-        for (volatile uint8_t __j = 0 ; __j < 5 ; __j++) {} ;
+        __asm volatile (
+            "movi %0, %1" "\n"
+            "1: addi %0, %0, -1" "\n"
+            "bnez %0, 1b" "\n"
+        : "=a" (delay) : "i" (I2C_CUSTOM_DELAY_160MHZ));
     }
     else
     {
-        for (volatile uint8_t __j = 0 ; __j < 0 ; __j++) {} ;
+        __asm volatile (
+            "movi %0, %1" "\n"
+            "1: addi %0, %0, -1" "\n"
+            "bnez %0, 1b" "\n"
+        : "=a" (delay) : "i" (I2C_CUSTOM_DELAY_80MHZ));
     }
 }
 
@@ -129,7 +146,7 @@ void i2c_start(void)
 }
 
 // Output stop condition
-void i2c_stop(void)
+bool i2c_stop(void)
 {
     uint32_t clk_stretch = CLK_STRETCH;
     // Set SDA to 0
@@ -144,7 +161,12 @@ void i2c_stop(void)
         debug("arbitration lost in i2c_stop");
     }
     i2c_delay();
+    if (!started) {
+        debug("link was break!");
+        return false ; //If bus was stop in other way, the current transmission Failed
+    }
     started = false;
+    return true;
 }
 
 // Write a bit to I2C bus
@@ -208,6 +230,36 @@ uint8_t i2c_read(bool ack)
     return byte;
 }
 
+static int i2c_bus_test(bool force)
+{
+    taskENTER_CRITICAL(); // To prevent task swaping after checking flag and before set it!
+    bool status = flag ; // get current status
+    if(force)
+    {
+        flag = true ; // force bus on
+        taskEXIT_CRITICAL();
+        if(status)
+           i2c_stop(); //Bus was busy, stop it.
+
+    }
+    else
+    {
+        if (status)
+        {
+            taskEXIT_CRITICAL();
+            debug("busy");
+            taskYIELD(); // If bus busy, change task to try finish last com.
+            return -EBUSY ;  // If bus busy, dont read
+        }
+        else
+        {
+            flag = true ; // Set Bus busy
+            taskEXIT_CRITICAL();
+        }
+    }
+    return 0 ;
+}
+
 bool i2c_slave_write(uint8_t slave_addr, uint8_t *data, uint8_t len)
 {
     bool success = false;
@@ -217,8 +269,10 @@ bool i2c_slave_write(uint8_t slave_addr, uint8_t *data, uint8_t len)
         if (!i2c_write(slave_addr << 1))
             break;
         while (len--) {
-            if (!i2c_write(*data++))
+            if (!i2c_write(*data++)) {
+                debug("Device dont Ack");
                 break;
+            }
         }
         i2c_stop();
         success = true;
@@ -233,12 +287,14 @@ bool i2c_slave_read(uint8_t slave_addr, uint8_t data, uint8_t *buf, uint32_t len
     do {
         i2c_start();
         if (!i2c_write(slave_addr << 1)) {
+            debug("Device dont Ack");
             break;
         }
         i2c_write(data);
         i2c_stop();
         i2c_start();
         if (!i2c_write(slave_addr << 1 | 1)) { // Slave address + read
+            debug("Device dont Ack");
             break;
         }
         while(len) {
@@ -254,3 +310,62 @@ bool i2c_slave_read(uint8_t slave_addr, uint8_t data, uint8_t *buf, uint32_t len
     }
     return success;
 }
+
+int i2c_slave_write_16(uint8_t slave_addr, uint8_t *data, uint16_t *buf, uint8_t len, bool force)
+{
+    if(i2c_bus_test(force))
+        return -EBUSY ;
+    i2c_start();
+    if (!i2c_write(slave_addr << 1))
+        goto error;
+    if(data != NULL) {
+        if (!i2c_write(*data))
+            goto error;
+    }
+    while (len--) {
+        if (!i2c_write((uint8_t)(*buf >> 8)))
+            goto error;
+        if (!i2c_write((uint8_t)(*buf++)))
+            goto error;
+    }
+    i2c_stop();
+    flag = false ; // Bus free
+    return 0;
+
+    error:
+    debug("Device dont Ack");
+    i2c_stop();
+    flag = false ; // Bus free
+    return -EIO;
+}
+
+int i2c_slave_read_16(uint8_t slave_addr, uint8_t *data, uint16_t *buf, uint32_t len, bool force)
+{
+    if(i2c_bus_test(force))
+        return -EBUSY ;
+    if(data != NULL) {
+        i2c_start();
+        if (!i2c_write(slave_addr << 1))
+            goto error;
+        if (!i2c_write(*data))
+            goto error;
+        i2c_stop();
+    }
+    i2c_start();
+    if (!i2c_write(slave_addr << 1 | 1)) // Slave address + read
+        goto error;
+    while(len) {
+        *buf = i2c_read(0) << 8  |  i2c_read(len == 1) ;
+        buf++;
+        len--;
+    }
+    i2c_stop();
+    flag = false ; // Bus free
+    return 0;
+
+    error:
+    debug("Device dont Ack");
+    i2c_stop();
+    flag = false ; // Bus free
+    return -EIO;
+}

extras/i2c/i2c.h

@@ -27,16 +27,39 @@
 
 #include <stdint.h>
 #include <stdbool.h>
+#include <errno.h>
+#include <FreeRTOS.h>
+#include <task.h>
 
 #ifdef	__cplusplus
 extern "C" {
 #endif
 
+
+#define I2C_FREQUENCY_400K true  // for test WIP
+
+/*
+ *  Some bit can be transmit slower.
+ *  Selected frequency fix the speed of a bit transmission
+ *  I2C lib take the maximum frequency defined
+ */
+
+#ifdef I2C_FREQUENCY_500K
+#define I2C_CUSTOM_DELAY_160MHZ   6
+#define I2C_CUSTOM_DELAY_80MHZ    1   //Sry, maximum is 320kHz at 80MHz
+#elif defined(I2C_FREQUENCY_400K)
+#define I2C_CUSTOM_DELAY_160MHZ   10
+#define I2C_CUSTOM_DELAY_80MHZ    1   //Sry, maximum is 320kHz at 80MHz
+#else
+#define I2C_CUSTOM_DELAY_160MHZ   100
+#define I2C_CUSTOM_DELAY_80MHZ    20
+#endif
+
 // I2C driver for ESP8266 written for use with esp-open-rtos
 // Based on https://en.wikipedia.org/wiki/I²C#Example_of_bit-banging_the_I.C2.B2C_Master_protocol
 // With calling overhead, we end up at ~320kbit/s
 
-///////Level 0 API
+//Level 0 API
 
 /**
  * Init bitbanging I2C driver on given pins
@@ -66,8 +89,9 @@ void i2c_start(void);
 
 /**
  * Send stop condition
+ * @return false if link was broken
  */
-void i2c_stop(void);
+bool i2c_stop(void);
 
 /**
  * get status from I2C bus.
@@ -75,10 +99,10 @@ void i2c_stop(void);
  */
 bool i2c_status(void);
 
-///////Level 1 API (Don't need functions above)
+//Level 1 API (Don't need functions above)
 
 /**
- * Write 'len' bytes from 'buf' to slave. Return true if slave acked.
+ * Write 'len' bytes from 'buf' to slave.
  * @param slave_addr slave device address
  * @param buf Pointer to data buffer
  * @param len Number of byte to send
@@ -87,7 +111,7 @@ bool i2c_status(void);
 bool i2c_slave_write(uint8_t slave_addr, uint8_t *buf, uint8_t len);
 
 /**
- * Issue a read operation and send 'data', followed by reading 'len' bytes
+ * Issue a read operation and read 'data', followed by reading 'len' bytes
  * from slave into 'buf'.
  * @param slave_addr slave device address
  * @param data register address to send
@@ -97,6 +121,29 @@ bool i2c_slave_write(uint8_t slave_addr, uint8_t *buf, uint8_t len);
  */
 bool i2c_slave_read(uint8_t slave_addr, uint8_t data, uint8_t *buf, uint32_t len);
 
+/**
+ * Write len word at register.
+ * @param slave_addr slave device address
+ * @param data Register address pointer to send  (ignored if NULL)
+ * @param buf Pointer to 16 bits data buffer
+ * @param len Number of word to read
+ * @param force If true, current i2c link will be break to force this one (Use with precaution)
+ * @return Non-zero if error occured
+ */
+int i2c_slave_write_16(uint8_t slave_addr, uint8_t *data, uint16_t *buf, uint8_t len, bool force);
+
+/**
+ * Issue a read operation at 'data'(!= NULL) , followed by reading 'len' bytes
+ * from slave into 'buf'.
+ * @param slave_addr slave device address
+ * @param data Register address pointer to send  (ignored if NULL)
+ * @param buf Pointer to 16 bits data buffer
+ * @param len Number of word to read
+ * @param force If true, current i2c link will be break to force this one (Use with precaution)
+ * @return Non-zero if error occured
+ */
+int i2c_slave_read_16(uint8_t slave_addr, uint8_t *data, uint16_t *buf, uint32_t len, bool force);
+
 
 #ifdef	__cplusplus
 }