Move cm3 type to generic types header.

[bertos.git] / bertos / drv / i2c_bitbang.c

diff --git a/bertos/drv/i2c_bitbang.c b/bertos/drv/i2c_bitbang.c
index 71374e98583c343dcbaf67978eb09cfae45a6195..45847c93c4e598bc2f0d66106bd110294cdaa2ed 100644 (file)
--- a/bertos/drv/i2c_bitbang.c
+++ b/bertos/drv/i2c_bitbang.c
@@ -32,7 +32,6 @@
  *
  * \brief I2C bitbang driver (implementation)
  *
- * \version $Id: adc.c 1604 2008-08-10 17:19:51Z bernie $
  * \author Francesco Sacchi <batt@develer.com>
  */
 
@@ -43,21 +42,26 @@
 #define LOG_FORMAT I2C_LOG_FORMAT
 
 #include <cfg/log.h>
+#include <cfg/macros.h>
 #include <cfg/module.h>
 
+#include <drv/timer.h>
+#include <cpu/irq.h>
+
 #include "hw/hw_i2c_bitbang.h"
 
-INLINE bool i2c_start(void)
+INLINE bool i2c_bitbang_start(void)
 {
        SDA_HI;
        SCL_HI;
        I2C_HALFBIT_DELAY();
        SDA_LO;
        I2C_HALFBIT_DELAY();
+
        return !SDA_IN;
 }
 
-void i2c_stop(void)
+void i2c_bitbang_stop(void)
 {
        SDA_LO;
        SCL_HI;
@@ -65,7 +69,7 @@ void i2c_stop(void)
        SDA_HI;
 }
 
-bool i2c_put(uint8_t _data)
+bool i2c_bitbang_put(uint8_t _data)
 {
        /* Add ACK bit */
        uint16_t data = (_data << 1) | 1;
@@ -89,7 +93,7 @@ bool i2c_put(uint8_t _data)
        return ack;
 }
 
-bool i2c_start_w(uint8_t id)
+bool i2c_bitbang_start_w(uint8_t id)
 {
        id &= ~I2C_READBIT;
        /*
@@ -99,9 +103,9 @@ bool i2c_start_w(uint8_t id)
         * keep trying until the deveice responds with an ACK.
         */
        ticks_t start = timer_clock();
-       while (i2c_start())
+       while (i2c_bitbang_start())
        {
-               if (i2c_put(id))
+               if (i2c_bitbang_put(id))
                        return true;
                else if (timer_clock() - start > ms_to_ticks(CONFIG_I2C_START_TIMEOUT))
                {
@@ -114,12 +118,12 @@ bool i2c_start_w(uint8_t id)
        return false;
 }
 
-bool i2c_start_r(uint8_t id)
+bool i2c_bitbang_start_r(uint8_t id)
 {
        id |= I2C_READBIT;
-       if (i2c_start())
+       if (i2c_bitbang_start())
        {
-               if (i2c_put(id))
+               if (i2c_bitbang_put(id))
                        return true;
 
                LOG_ERR("NACK on I2c start read\n");
@@ -128,7 +132,7 @@ bool i2c_start_r(uint8_t id)
        return false;
 }
 
-int i2c_get(bool ack)
+int i2c_bitbang_get(bool ack)
 {
        uint8_t data = 0;
        for (uint8_t i = 0x80; i != 0; i >>= 1)
@@ -164,11 +168,127 @@ MOD_DEFINE(i2c);
 /**
  * Initialize i2c module.
  */
-void i2c_init(void)
+void i2c_bitbang_init(void)
 {
+       MOD_CHECK(timer);
        I2C_BITBANG_HW_INIT;
        SDA_HI;
        SCL_HI;
        MOD_INIT(i2c);
 }
 
+
+/*
+ * New I2C API
+ */
+
+static void i2c_bitbang_stop(struct I2c *i2c)
+{
+       SDA_LO;
+       SCL_HI;
+       I2C_HALFBIT_DELAY();
+       SDA_HI;
+}
+
+
+void i2c_bitbang_start(struct I2c *i2c, uint16_t slave_addr)
+{
+       if (i2c->flags & I2C_START_R)
+               slave_addr |= I2C_READBIT;
+       else
+               slave_addr &= ~I2C_READBIT;
+
+       /*
+        * Loop on the select write sequence: when the device is busy
+        * writing previously sent data it will reply to the SLA_W
+        * control byte with a NACK.  In this case, we must
+        * keep trying until the deveice responds with an ACK.
+        */
+       ticks_t start = timer_clock();
+       while (i2c_bitbang_start())
+       {
+               if (i2c_bitbang_put(slave_addr))
+                       return;
+               else if (timer_clock() - start > ms_to_ticks(CONFIG_I2C_START_TIMEOUT))
+               {
+                       LOG_ERR("Timeout on I2C start\n");
+                       i2c->errors |= I2C_START_TIMEOUT;
+                       i2c_bitbang_stop(i2c);
+                       return;
+               }
+       }
+
+       LOG_ERR("START arbitration lost\n");
+       i2c->errors |= I2C_ARB_LOST;
+       i2c_bitbang_stop(i2c);
+       return;
+}
+
+uint8_t i2c_bitbang_get(struct I2c *i2c)
+{
+       uint8_t data = 0;
+       for (uint8_t i = 0x80; i != 0; i >>= 1)
+       {
+               SCL_LO;
+               I2C_HALFBIT_DELAY();
+               SCL_HI;
+               if (SDA_IN)
+                       data |= i;
+               else
+                       data &= ~i;
+
+               I2C_HALFBIT_DELAY();
+       }
+       SCL_LO;
+
+       /* Generate ACK/NACK */
+       if (i2c->xfer_size > 1)
+               SDA_LO;
+       else
+               SDA_HI;
+
+       I2C_HALFBIT_DELAY();
+       SCL_HI;
+       I2C_HALFBIT_DELAY();
+       SCL_LO;
+       SDA_HI;
+
+       /* Generate stop condition (if requested) */
+       if ((i2c->xfer_size == 1) && (i2c->flags & I2C_STOP))
+               i2c_bitbang_stop(i2c);
+
+       return data;
+}
+
+void i2c_bitbang_put(struct I2c *i2c, uint8_t _data)
+{
+       /* Add ACK bit */
+       uint16_t data = (_data << 1) | 1;
+
+       for (uint16_t i = 0x100; i != 0; i >>= 1)
+       {
+               SCL_LO;
+               if (data & i)
+                       SDA_HI;
+               else
+                       SDA_LO;
+               I2C_HALFBIT_DELAY();
+
+               SCL_HI;
+               I2C_HALFBIT_DELAY();
+       }
+
+       bool ack = !SDA_IN;
+       SCL_LO;
+       I2C_HALFBIT_DELAY();
+
+       if (!ack)
+       {
+               LOG_ERR("NO ACK received\n");
+               i2c->errors |= I2C_NO_ACK;
+       }
+
+       /* Generate stop condition (if requested) */
+       if (((i2c->xfer_size == 1) && (i2c->flags & I2C_STOP)) || i2c->errors)
+               i2c_bitbang_stop(i2c);
+}