Merged revisions 4004-4036,4039-4048,4050-4095,4097-4100 via svnmerge from

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

diff --git a/bertos/drv/i2c_bitbang.c b/bertos/drv/i2c_bitbang.c
index 1d7e98d6819c0d7b86ec09829e3ca38cad274455..2cf0e573aaee4b918cb3c45f727e895e8e3090d3 100644 (file)
--- a/bertos/drv/i2c_bitbang.c
+++ b/bertos/drv/i2c_bitbang.c
@@ -32,11 +32,12 @@
  *
  * \brief I2C bitbang driver (implementation)
  *
- * \version $Id$
  * \author Francesco Sacchi <batt@develer.com>
+ * \author Daniele Basile <asterix@develer.com>
  */
 
-#include "i2c.h"
+#include "hw/hw_i2c_bitbang.h"
+
 #include "cfg/cfg_i2c.h"
 
 #define LOG_LEVEL  I2C_LOG_LEVEL
@@ -47,9 +48,12 @@
 #include <cfg/module.h>
 
 #include <drv/timer.h>
+#include <drv/i2c.h>
+
 #include <cpu/irq.h>
 
-#include "hw/hw_i2c_bitbang.h"
+#include <cpu/attr.h>
+
 
 INLINE bool i2c_bitbang_start(void)
 {
@@ -58,7 +62,7 @@ INLINE bool i2c_bitbang_start(void)
        I2C_HALFBIT_DELAY();
        SDA_LO;
        I2C_HALFBIT_DELAY();
-       ASSERT(!SDA_IN);
+
        return !SDA_IN;
 }
 
@@ -178,3 +182,159 @@ void i2c_bitbang_init(void)
        MOD_INIT(i2c);
 }
 
+
+/*
+ * New I2C API
+ */
+#define I2C_DEV(i2c)            ((int)((i2c)->hw))
+
+static void i2c_bitbang_stop_1(struct I2c *i2c)
+{
+       i2c_hw_sdaLo(I2C_DEV(i2c));
+       i2c_hw_sclHi(I2C_DEV(i2c));
+       i2c_hw_halfbitDelay(I2C_DEV(i2c));
+       i2c_hw_sdaHi(I2C_DEV(i2c));
+}
+
+INLINE bool i2c_bitbang_start_1(struct I2c *i2c)
+{
+       i2c_hw_sdaHi(I2C_DEV(i2c));
+       i2c_hw_sclHi(I2C_DEV(i2c));
+       i2c_hw_halfbitDelay(I2C_DEV(i2c));
+       i2c_hw_sdaLo(I2C_DEV(i2c));
+       i2c_hw_halfbitDelay(I2C_DEV(i2c));
+
+       return !i2c_hw_sdaIn(I2C_DEV(i2c));
+}
+
+
+static uint8_t i2c_bitbang_getc(struct I2c *i2c)
+{
+       uint8_t data = 0;
+       for (uint8_t i = 0x80; i != 0; i >>= 1)
+       {
+               i2c_hw_sclLo(I2C_DEV(i2c));
+               i2c_hw_halfbitDelay(I2C_DEV(i2c));
+               i2c_hw_sclHi(I2C_DEV(i2c));
+               if (i2c_hw_sdaIn(I2C_DEV(i2c)))
+                       data |= i;
+               else
+                       data &= ~i;
+
+               i2c_hw_halfbitDelay(I2C_DEV(i2c));
+       }
+       i2c_hw_sclLo(I2C_DEV(i2c));
+
+       /* Generate ACK/NACK */
+       if (i2c->xfer_size > 1)
+               i2c_hw_sdaLo(I2C_DEV(i2c));
+       else
+               i2c_hw_sdaHi(I2C_DEV(i2c));
+
+       i2c_hw_halfbitDelay(I2C_DEV(i2c));
+       i2c_hw_sclHi(I2C_DEV(i2c));
+       i2c_hw_halfbitDelay(I2C_DEV(i2c));
+       i2c_hw_sclLo(I2C_DEV(i2c));
+       i2c_hw_sdaHi(I2C_DEV(i2c));
+
+       /* Generate stop condition (if requested) */
+       if ((i2c->xfer_size == 1) && (i2c->flags & I2C_STOP))
+               i2c_bitbang_stop_1(i2c);
+
+       return data;
+}
+
+static void i2c_bitbang_putc(struct I2c *i2c, uint8_t _data)
+{
+       /* Add ACK bit */
+       uint16_t data = (_data << 1) | 1;
+
+       for (uint16_t i = 0x100; i != 0; i >>= 1)
+       {
+               i2c_hw_sclLo(I2C_DEV(i2c));
+               if (data & i)
+                       i2c_hw_sdaHi(I2C_DEV(i2c));
+               else
+                       i2c_hw_sdaLo(I2C_DEV(i2c));
+               i2c_hw_halfbitDelay(I2C_DEV(i2c));
+
+               i2c_hw_sclHi(I2C_DEV(i2c));
+               i2c_hw_halfbitDelay(I2C_DEV(i2c));
+       }
+
+       bool ack = !i2c_hw_sdaIn(I2C_DEV(i2c));
+       i2c_hw_sclLo(I2C_DEV(i2c));
+       i2c_hw_halfbitDelay(I2C_DEV(i2c));
+
+       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_1(i2c);
+}
+
+
+static void i2c_bitbang_start_2(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_1(i2c))
+       {
+               i2c_bitbang_putc(i2c, slave_addr);
+
+               if (!(i2c->errors & I2C_NO_ACK))
+                       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_1(i2c);
+                       return;
+               }
+       }
+
+       LOG_ERR("START arbitration lost\n");
+       i2c->errors |= I2C_ARB_LOST;
+       i2c_bitbang_stop_1(i2c);
+       return;
+}
+
+
+static const I2cVT i2c_bitbang_vt =
+{
+       .start = i2c_bitbang_start_2,
+       .getc = i2c_bitbang_getc,
+       .putc = i2c_bitbang_putc,
+       .write = i2c_genericWrite,
+       .read = i2c_genericRead,
+};
+
+
+/**
+ * Initialize i2c module.
+ */
+void i2c_hw_bitbangInit(I2c *i2c, int dev)
+{
+       MOD_CHECK(timer);
+       i2c->hw = (struct I2cHardware *)(dev - I2C_BITBANG0);
+       i2c->vt = &i2c_bitbang_vt;
+
+       i2c_hw_bitbang_init(I2C_DEV(i2c));
+       i2c_hw_sdaHi(I2C_DEV(i2c));
+       i2c_hw_sclHi(I2C_DEV(i2c));
+}
+