diff options
Diffstat (limited to 'os/hal/lib/fallback/I2C/hal_i2c_lld.c')
| -rw-r--r-- | os/hal/lib/fallback/I2C/hal_i2c_lld.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/os/hal/lib/fallback/I2C/hal_i2c_lld.c b/os/hal/lib/fallback/I2C/hal_i2c_lld.c index 6fbdfdd6d..82b17663a 100644 --- a/os/hal/lib/fallback/I2C/hal_i2c_lld.c +++ b/os/hal/lib/fallback/I2C/hal_i2c_lld.c @@ -30,6 +30,11 @@ /* Driver local definitions. */
/*===========================================================================*/
+#define CHECK_ERROR(msg) \
+ if ((msg) < (msg_t)0) { \
+ return MSG_TIMEOUT; \
+ }
+
/*===========================================================================*/
/* Driver constants. */
/*===========================================================================*/
@@ -66,6 +71,100 @@ I2CDriver I2CD4; /* Driver local functions. */
/*===========================================================================*/
+static msg_t i2c_delay(I2CDriver *i2cp) {
+
+ if (!osalOsIsTimeWithinX(osalOsGetSystemTimeX(), i2cp->start, i2cp->end)) {
+ return MSG_TIMEOUT;
+ }
+
+#if SW_I2C_USE_OSAL_DELAY || defined(__DOXYGEN__)
+ osalThreadSleep(i2cp->config->ticks);
+#else
+ i2cp->config->delay();
+#endif
+ return MSG_OK;
+}
+
+static msg_t i2c_write_start(I2CDriver *i2cp) {
+
+}
+
+static msg_t i2c_write_restart(I2CDriver *i2cp) {
+
+}
+
+static msg_t i2c_write_stop(I2CDriver *i2cp) {
+
+}
+
+static msg_t i2c_writebit(I2CDriver *i2cp, unsigned bit) {
+
+ palWriteLine(i2cp->config->sda, bit);
+ CHECK_ERROR(i2c_delay(i2cp));
+ palSetLine(i2cp->config->scl);
+ CHECK_ERROR(i2c_delay(i2cp));
+
+ /* Clock stretching.*/
+ while (palReadLine(i2cp->config->scl) == PAL_LOW) {
+ CHECK_ERROR(i2c_delay(i2cp));
+ }
+
+ /* Arbitration check.*/
+ if ((bit == PAL_HIGH) && (palReadLine(i2cp->config->sda) == PAL_LOW)) {
+ i2cp->errors |= I2C_ARBITRATION_LOST;
+ return MSG_RESET;
+ }
+
+ palClearLine(i2cp->config->scl);
+
+ return MSG_OK;
+}
+
+static msg_t i2c_readbit(I2CDriver *i2cp) {
+ msg_t bit;
+
+ palSetLine(i2cp->config->sda);
+ CHECK_ERROR(i2c_delay(i2cp));
+ palSetLine(i2cp->config->scl);
+
+ /* Clock stretching.*/
+ while (palReadLine(i2cp->config->scl) == PAL_LOW) {
+ CHECK_ERROR(i2c_delay(i2cp));
+ }
+
+ CHECK_ERROR(i2c_delay(i2cp));
+ bit = palReadLine(i2cp->config->sda);
+ palClearLine(i2cp->config->scl);
+
+ return bit;
+}
+
+static msg_t i2c_writebyte(I2CDriver *i2cp, uint8_t byte) {
+ uint8_t mask;
+
+ for (mask = 0x80U; mask > 0U; mask >>= 1U) {
+ CHECK_ERROR(i2c_writebit(i2cp, (byte & mask) != 0));
+ }
+
+ return i2c_readbit(i2cp);
+}
+
+static msg_t i2c_readbyte(I2CDriver *i2cp, unsigned nack) {
+ msg_t byte;
+ unsigned i;
+
+ byte = 0U;
+ for (i = 0; i < 8; i++) {
+ msg_t msg = i2c_readbit(i2cp);
+ CHECK_ERROR(msg);
+ byte = (byte << 1U) | msg;
+ }
+
+ CHECK_ERROR(i2c_writebit(i2cp, PAL_LOW));
+
+ return byte;
+}
+
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
|