* \brief I2C bitbang driver (implementation)
*
* \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
#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>
+
+#if !CONFIG_I2C_DISABLE_OLD_API
INLINE bool i2c_bitbang_start(void)
{
return (int)(uint8_t)data;
}
-MOD_DEFINE(i2c);
+#endif /* !CONFIG_I2C_DISABLE_OLD_API */
-/**
- * Initialize i2c module.
+/*
+ * New I2C API
*/
-void i2c_bitbang_init(void)
+static bool old_api = false;
+#define I2C_DEV(i2c) ((int)((i2c)->hw))
+
+static void i2c_bitbang_stop_1(struct I2c *i2c)
{
- MOD_CHECK(timer);
- I2C_BITBANG_HW_INIT;
- SDA_HI;
- SCL_HI;
- MOD_INIT(i2c);
+ if (old_api)
+ {
+ SDA_LO;
+ SCL_HI;
+ I2C_HALFBIT_DELAY();
+ SDA_HI;
+ }
+ else
+ {
+ i2c_sdaLo(I2C_DEV(i2c));
+ i2c_sclHi(I2C_DEV(i2c));
+ i2c_halfbitDelay(I2C_DEV(i2c));
+ i2c_sdaHi(I2C_DEV(i2c));
+ }
}
+INLINE bool i2c_bitbang_start_1(struct I2c *i2c)
+{
+ bool ret;
+ /* Clear all error, we restart */
+ i2c->errors &= ~(I2C_NO_ACK | I2C_ARB_LOST);
-/*
- * New I2C API
- */
+ if (old_api)
+ {
+ SDA_HI;
+ SCL_HI;
+ I2C_HALFBIT_DELAY();
+ SDA_LO;
+ I2C_HALFBIT_DELAY();
+
+ ret = !SDA_IN;
+ }
+ else
+ {
+ i2c_sdaHi(I2C_DEV(i2c));
+ i2c_sclHi(I2C_DEV(i2c));
+ i2c_halfbitDelay(I2C_DEV(i2c));
+ i2c_sdaLo(I2C_DEV(i2c));
+ i2c_halfbitDelay(I2C_DEV(i2c));
+
+ ret = !i2c_sdaIn(I2C_DEV(i2c));
+ }
+
+ return ret;
+}
-static void i2c_bitbang_stop(struct I2c *i2c)
+
+static uint8_t i2c_bitbang_getc(struct I2c *i2c)
{
- SDA_LO;
- SCL_HI;
- I2C_HALFBIT_DELAY();
- SDA_HI;
+ uint8_t data = 0;
+ if (old_api)
+ {
+ 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;
+ }
+ else
+ {
+ for (uint8_t i = 0x80; i != 0; i >>= 1)
+ {
+ i2c_sclLo(I2C_DEV(i2c));
+ i2c_halfbitDelay(I2C_DEV(i2c));
+ i2c_sclHi(I2C_DEV(i2c));
+ if (i2c_sdaIn(I2C_DEV(i2c)))
+ data |= i;
+ else
+ data &= ~i;
+
+ i2c_halfbitDelay(I2C_DEV(i2c));
+ }
+ i2c_sclLo(I2C_DEV(i2c));
+
+ /* Generate ACK/NACK */
+ if (i2c->xfer_size > 1)
+ i2c_sdaLo(I2C_DEV(i2c));
+ else
+ i2c_sdaHi(I2C_DEV(i2c));
+
+ i2c_halfbitDelay(I2C_DEV(i2c));
+ i2c_sclHi(I2C_DEV(i2c));
+ i2c_halfbitDelay(I2C_DEV(i2c));
+ i2c_sclLo(I2C_DEV(i2c));
+ i2c_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;
+}
+
+INLINE void i2c_bitbang_putcStop(struct I2c *i2c, uint8_t _data, bool stop)
+{
+ /* Add ACK bit */
+ uint16_t data = (_data << 1) | 1;
+ bool ack;
+
+ if (old_api)
+ {
+ 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();
+ }
+
+ ack = !SDA_IN;
+ SCL_LO;
+ I2C_HALFBIT_DELAY();
+ }
+ else
+ {
+ for (uint16_t i = 0x100; i != 0; i >>= 1)
+ {
+ i2c_sclLo(I2C_DEV(i2c));
+ if (data & i)
+ i2c_sdaHi(I2C_DEV(i2c));
+ else
+ i2c_sdaLo(I2C_DEV(i2c));
+ i2c_halfbitDelay(I2C_DEV(i2c));
+
+ i2c_sclHi(I2C_DEV(i2c));
+ i2c_halfbitDelay(I2C_DEV(i2c));
+ }
+ ack = !i2c_sdaIn(I2C_DEV(i2c));
+
+ i2c_sclLo(I2C_DEV(i2c));
+ i2c_halfbitDelay(I2C_DEV(i2c));
+ }
+
+ if (!ack)
+ i2c->errors |= I2C_NO_ACK;
+
+ /* Generate stop condition (if requested) */
+ if (stop || i2c->errors)
+ i2c_bitbang_stop_1(i2c);
}
+static void i2c_bitbang_putc(struct I2c *i2c, uint8_t data)
+{
+ i2c_bitbang_putcStop(i2c, data,
+ (i2c->xfer_size == 1) && (i2c->flags & I2C_STOP));
+}
-void i2c_bitbang_start(struct I2c *i2c, uint16_t slave_addr)
+static void i2c_bitbang_start_2(struct I2c *i2c, uint16_t slave_addr)
{
if (i2c->flags & I2C_START_R)
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.
+ * keep trying until the device responds with an ACK.
*/
ticks_t start = timer_clock();
- while (i2c_bitbang_start())
+ while (i2c_bitbang_start_1(i2c))
{
- if (i2c_bitbang_put(slave_addr))
+ i2c_bitbang_putcStop(i2c, slave_addr, false);
+
+ 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(i2c);
+ i2c_bitbang_stop_1(i2c);
return;
}
}
LOG_ERR("START arbitration lost\n");
i2c->errors |= I2C_ARB_LOST;
- i2c_bitbang_stop(i2c);
+ i2c_bitbang_stop_1(i2c);
return;
}
-uint8_t i2c_bitbang_get(struct I2c *i2c)
+
+static const I2cVT i2c_bitbang_vt =
{
- 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;
+ .start = i2c_bitbang_start_2,
+ .getc = i2c_bitbang_getc,
+ .putc = i2c_bitbang_putc,
+ .write = i2c_genericWrite,
+ .read = i2c_genericRead,
+};
- I2C_HALFBIT_DELAY();
- }
- SCL_LO;
- /* Generate ACK/NACK */
- if (i2c->xfer_size > 1)
- SDA_LO;
+/**
+ * Initialize i2c module.
+ */
+void i2c_hw_bitbangInit(I2c *i2c, int dev)
+{
+ MOD_CHECK(timer);
+ if (dev == I2C_BITBANG_OLD)
+ old_api = true;
else
- SDA_HI;
-
- I2C_HALFBIT_DELAY();
- SCL_HI;
- I2C_HALFBIT_DELAY();
- SCL_LO;
- SDA_HI;
+ i2c->hw = (struct I2cHardware *)(dev - I2C_BITBANG0);
- /* Generate stop condition (if requested) */
- if ((i2c->xfer_size == 1) && (i2c->flags & I2C_STOP))
- i2c_bitbang_stop(i2c);
-
- return data;
-}
+ i2c->vt = &i2c_bitbang_vt;
-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)
+ if (old_api)
{
- SCL_LO;
- if (data & i)
- SDA_HI;
- else
- SDA_LO;
- I2C_HALFBIT_DELAY();
-
+ I2C_BITBANG_HW_INIT;
+ SDA_HI;
SCL_HI;
- I2C_HALFBIT_DELAY();
}
-
- bool ack = !SDA_IN;
- SCL_LO;
- I2C_HALFBIT_DELAY();
-
- if (!ack)
+ else
{
- LOG_ERR("NO ACK received\n");
- i2c->errors |= I2C_NO_ACK;
+ i2c_bitbangInit(I2C_DEV(i2c));
+ i2c_sdaHi(I2C_DEV(i2c));
+ i2c_sclHi(I2C_DEV(i2c));
}
-
- /* Generate stop condition (if requested) */
- if (((i2c->xfer_size == 1) && (i2c->flags & I2C_STOP)) || i2c->errors)
- i2c_bitbang_stop(i2c);
}
+