diff options
Diffstat (limited to 'os/hal/ports/AVR/hal_i2c_lld.c')
| -rw-r--r-- | os/hal/ports/AVR/hal_i2c_lld.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/os/hal/ports/AVR/hal_i2c_lld.c b/os/hal/ports/AVR/hal_i2c_lld.c new file mode 100644 index 000000000..9d5bd4df0 --- /dev/null +++ b/os/hal/ports/AVR/hal_i2c_lld.c @@ -0,0 +1,266 @@ +/*
+ ChibiOS - Copyright (C) 2006..2016 Giovanni Di Sirio
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+/**
+ * @file AVR/i2c_lld.c
+ * @brief AVR I2C subsystem low level driver source.
+ *
+ * @addtogroup I2C
+ * @{
+ */
+
+#include "hal.h"
+
+#if HAL_USE_I2C || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver local definitions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+/** @brief I2C driver identifier.*/
+#if AVR_I2C_USE_I2C1 || defined(__DOXYGEN__)
+I2CDriver I2CD1;
+#endif
+
+/*===========================================================================*/
+/* Driver local variables and types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local functions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+
+#if AVR_I2C_USE_I2C1 || defined(__DOXYGEN__)
+/**
+ * @brief I2C event interrupt handler.
+ *
+ * @notapi
+ */
+OSAL_IRQ_HANDLER(TWI_vect) {
+ OSAL_IRQ_PROLOGUE();
+
+ I2CDriver *i2cp = &I2CD1;
+
+ switch (TWSR & 0xF8) {
+ case TWI_START:
+ case TWI_REPEAT_START:
+ TWDR = (i2cp->addr << 1);
+ if ((i2cp->txbuf == NULL) || (i2cp->txbytes == 0) || (i2cp->txidx == i2cp->txbytes)) {
+ TWDR |= 0x01;
+ }
+ TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
+ break;
+ case TWI_MASTER_TX_ADDR_ACK:
+ case TWI_MASTER_TX_DATA_ACK:
+ if (i2cp->txidx < i2cp->txbytes) {
+ TWDR = i2cp->txbuf[i2cp->txidx++];
+ TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
+ } else {
+ if (i2cp->rxbuf && i2cp->rxbytes) {
+ TWCR = ((1 << TWSTA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
+ } else {
+ TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
+ _i2c_wakeup_isr(i2cp);
+ }
+ }
+ break;
+ case TWI_MASTER_RX_ADDR_ACK:
+ if (i2cp->rxidx == (i2cp->rxbytes - 1)) {
+ TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
+ } else {
+ TWCR = ((1 << TWEA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
+ }
+ break;
+ case TWI_MASTER_RX_DATA_ACK:
+ i2cp->rxbuf[i2cp->rxidx++] = TWDR;
+ if (i2cp->rxidx == (i2cp->rxbytes - 1)) {
+ TWCR = ((1 << TWINT) | (1 << TWEN) | (1 << TWIE));
+ } else {
+ TWCR = ((1 << TWEA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
+ }
+ break;
+ case TWI_MASTER_RX_DATA_NACK:
+ i2cp->rxbuf[i2cp->rxidx] = TWDR;
+ TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
+ _i2c_wakeup_isr(i2cp);
+ case TWI_MASTER_TX_ADDR_NACK:
+ case TWI_MASTER_TX_DATA_NACK:
+ case TWI_MASTER_RX_ADDR_NACK:
+ i2cp->errors |= I2C_ACK_FAILURE;
+ break;
+ case TWI_ARBITRATION_LOST:
+ i2cp->errors |= I2C_ARBITRATION_LOST;
+ break;
+ case TWI_BUS_ERROR:
+ i2cp->errors |= I2C_BUS_ERROR;
+ break;
+ default:
+ /* FIXME: only gets here if there are other MASTERs in the bus */
+ TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
+ _i2c_wakeup_error_isr(i2cp);
+ }
+
+ if (i2cp->errors != I2C_NO_ERROR) {
+ TWCR = ((1 << TWSTO) | (1 << TWINT) | (1 << TWEN));
+ _i2c_wakeup_error_isr(i2cp);
+ }
+
+ OSAL_IRQ_EPILOGUE();
+}
+#endif /* AVR_I2C_USE_I2C1 */
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level I2C driver initialization.
+ *
+ * @notapi
+ */
+void i2c_lld_init(void) {
+ i2cObjectInit(&I2CD1);
+ I2CD1.thread = NULL;
+}
+
+/**
+ * @brief Configures and activates the I2C peripheral.
+ *
+ * @param[in] i2cp pointer to the @p I2CDriver object
+ *
+ * @notapi
+ */
+void i2c_lld_start(I2CDriver *i2cp) {
+ uint32_t clock_speed = 100000;
+
+ /* TODO: Test TWI without external pull-ups (use internal) */
+
+ /* Configure prescaler to 1 */
+ TWSR &= 0xF8;
+
+ if (i2cp->config != NULL)
+ clock_speed = i2cp->config->clock_speed;
+
+ /* Configure baudrate */
+ TWBR = ((F_CPU / clock_speed) - 16) / 2;
+}
+
+/**
+ * @brief Deactivates the I2C peripheral.
+ *
+ * @param[in] i2cp pointer to the @p I2CDriver object
+ *
+ * @notapi
+ */
+void i2c_lld_stop(I2CDriver *i2cp) {
+
+ if (i2cp->state != I2C_STOP) {
+ /* Disable TWI subsystem and stop all operations */
+ TWCR &= ~(1 << TWEN);
+ }
+}
+
+/**
+ * @brief Receives data via the I2C bus as master.
+ *
+ * @param[in] i2cp pointer to the @p I2CDriver object
+ * @param[in] addr slave device address
+ * @param[out] rxbuf pointer to the receive buffer
+ * @param[in] rxbytes number of bytes to be received
+ * @param[in] timeout the number of ticks before the operation timeouts,
+ * the following special values are allowed:
+ * - @a TIME_INFINITE no timeout.
+ * .
+ * @return The operation status.
+ * @retval MSG_OK if the function succeeded.
+ * @retval MSG_RESET if one or more I2C errors occurred, the errors can
+ * be retrieved using @p i2cGetErrors().
+ * @retval MSG_TIMEOUT if a timeout occurred before operation end. <b>After a
+ * timeout the driver must be stopped and restarted
+ * because the bus is in an uncertain state</b>.
+ *
+ * @notapi
+ */
+msg_t i2c_lld_master_receive_timeout(I2CDriver *i2cp, i2caddr_t addr,
+ uint8_t *rxbuf, size_t rxbytes,
+ systime_t timeout) {
+ i2cp->errors = I2C_NO_ERROR;
+ i2cp->addr = addr;
+ i2cp->txbuf = NULL;
+ i2cp->txbytes = 0;
+ i2cp->txidx = 0;
+ i2cp->rxbuf = rxbuf;
+ i2cp->rxbytes = rxbytes;
+ i2cp->rxidx = 0;
+
+ /* Send START */
+ TWCR = ((1 << TWSTA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
+
+ return osalThreadSuspendTimeoutS(&i2cp->thread, TIME_INFINITE);
+}
+
+/**
+ * @brief Transmits data via the I2C bus as master.
+ *
+ * @param[in] i2cp pointer to the @p I2CDriver object
+ * @param[in] addr slave device address
+ * @param[in] txbuf pointer to the transmit buffer
+ * @param[in] txbytes number of bytes to be transmitted
+ * @param[out] rxbuf pointer to the receive buffer
+ * @param[in] rxbytes number of bytes to be received
+ * @param[in] timeout the number of ticks before the operation timeouts,
+ * the following special values are allowed:
+ * - @a TIME_INFINITE no timeout.
+ * .
+ * @return The operation status.
+ * @retval MSG_OK if the function succeeded.
+ * @retval MSG_RESET if one or more I2C errors occurred, the errors can
+ * be retrieved using @p i2cGetErrors().
+ * @retval MSG_TIMEOUT if a timeout occurred before operation end. <b>After a
+ * timeout the driver must be stopped and restarted
+ * because the bus is in an uncertain state</b>.
+ *
+ * @notapi
+ */
+msg_t i2c_lld_master_transmit_timeout(I2CDriver *i2cp, i2caddr_t addr,
+ const uint8_t *txbuf, size_t txbytes,
+ uint8_t *rxbuf, size_t rxbytes,
+ systime_t timeout) {
+ i2cp->errors = I2C_NO_ERROR;
+ i2cp->addr = addr;
+ i2cp->txbuf = txbuf;
+ i2cp->txbytes = txbytes;
+ i2cp->txidx = 0;
+ i2cp->rxbuf = rxbuf;
+ i2cp->rxbytes = rxbytes;
+ i2cp->rxidx = 0;
+
+ TWCR = ((1 << TWSTA) | (1 << TWINT) | (1 << TWEN) | (1 << TWIE));
+
+ return osalThreadSuspendTimeoutS(&i2cp->thread, TIME_INFINITE);
+}
+
+#endif /* HAL_USE_I2C */
+
+/** @} */
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