diff options
Diffstat (limited to 'os/hal/ports/KINETIS/LLD/hal_i2c_lld.c')
| -rw-r--r-- | os/hal/ports/KINETIS/LLD/hal_i2c_lld.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/os/hal/ports/KINETIS/LLD/hal_i2c_lld.c b/os/hal/ports/KINETIS/LLD/hal_i2c_lld.c new file mode 100644 index 0000000..3659a93 --- /dev/null +++ b/os/hal/ports/KINETIS/LLD/hal_i2c_lld.c @@ -0,0 +1,414 @@ +/*
+ ChibiOS - Copyright (C) 2014-2015 Fabio Utzig
+
+ 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 KINETIS/LLD/i2c_lld.c
+ * @brief KINETIS I2C subsystem low level driver source.
+ *
+ * @addtogroup I2C
+ * @{
+ */
+
+#include "osal.h"
+#include "hal.h"
+
+#if HAL_USE_I2C || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver local definitions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+/**
+ * @brief I2C0 driver identifier.
+ */
+#if KINETIS_I2C_USE_I2C0 || defined(__DOXYGEN__)
+I2CDriver I2CD1;
+#endif
+
+/**
+ * @brief I2C1 driver identifier.
+ */
+#if KINETIS_I2C_USE_I2C1 || defined(__DOXYGEN__)
+I2CDriver I2CD2;
+#endif
+
+/*===========================================================================*/
+/* Driver local variables and types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local functions. */
+/*===========================================================================*/
+
+void config_frequency(I2CDriver *i2cp) {
+
+ /* Each index in the table corresponds to a a frequency
+ * divider used to generate the SCL clock from the main
+ * system clock.
+ */
+ uint16_t icr_table[] = {
+ /* 0x00 - 0x0F */
+ 20,22,24,26,28,30,34,40,28,32,36,40,44,48,56,68,
+ /* 0x10 - 0x1F */
+ 48,56,64,72,80,88,104,128,80,96,112,128,144,160,192,240,
+ /* 0x20 - 0x2F */
+ 160,192,224,256,288,320,384,480,320,384,448,512,576,640,768,960,
+ /* 0x30 - 0x3F */
+ 640,768,896,1024,1152,1280,1536,1920,1280,1536,1792,2048,2304,2560,3072,3840,
+ };
+
+ int length = sizeof(icr_table) / sizeof(icr_table[0]);
+ uint16_t divisor;
+ uint8_t i = 0, index = 0;
+ uint16_t best, diff;
+
+ if (i2cp->config != NULL)
+ divisor = KINETIS_SYSCLK_FREQUENCY / i2cp->config->clock;
+ else
+ divisor = KINETIS_SYSCLK_FREQUENCY / 100000;
+
+ best = ~0;
+ index = 0;
+ /* Tries to find the SCL clock which is the closest
+ * approximation to the clock passed in config. To
+ * stay on the safe side, only values that generate
+ * lower frequency are used.
+ */
+ for (i = 0; i < length; i++) {
+ if (icr_table[i] >= divisor) {
+ diff = icr_table[i] - divisor;
+ if (diff < best) {
+ best = diff;
+ index = i;
+ }
+ }
+ }
+
+ i2cp->i2c->F = index;
+}
+
+/**
+ * @brief Common IRQ handler.
+ * @note Tries hard to clear all the pending interrupt sources, we don't
+ * want to go through the whole ISR and have another interrupt soon
+ * after.
+ *
+ * @param[in] i2cp pointer to an I2CDriver
+ */
+static void serve_interrupt(I2CDriver *i2cp) {
+
+ I2C_TypeDef *i2c = i2cp->i2c;
+ intstate_t state = i2cp->intstate;
+
+ if (i2c->S & I2Cx_S_ARBL) {
+
+ i2cp->errors |= I2C_ARBITRATION_LOST;
+ i2c->S |= I2Cx_S_ARBL;
+
+ } else if (state == STATE_SEND) {
+
+ if (i2c->S & I2Cx_S_RXAK)
+ i2cp->errors |= I2C_ACK_FAILURE;
+ else if (i2cp->txbuf != NULL && i2cp->txidx < i2cp->txbytes)
+ i2c->D = i2cp->txbuf[i2cp->txidx++];
+ else
+ i2cp->intstate = STATE_STOP;
+
+ } else if (state == STATE_DUMMY) {
+
+ if (i2c->S & I2Cx_S_RXAK)
+ i2cp->errors |= I2C_ACK_FAILURE;
+ else {
+ i2c->C1 &= ~I2Cx_C1_TX;
+
+ if (i2cp->rxbytes > 1)
+ i2c->C1 &= ~I2Cx_C1_TXAK;
+ else
+ i2c->C1 |= I2Cx_C1_TXAK;
+ (void) i2c->D;
+ i2cp->intstate = STATE_RECV;
+ }
+
+ } else if (state == STATE_RECV) {
+
+ if (i2cp->rxbytes > 1) {
+ if (i2cp->rxidx == (i2cp->rxbytes - 2))
+ i2c->C1 |= I2Cx_C1_TXAK;
+ else
+ i2c->C1 &= ~I2Cx_C1_TXAK;
+ }
+
+ if (i2cp->rxidx == i2cp->rxbytes - 1)
+ i2c->C1 &= ~(I2Cx_C1_TX | I2Cx_C1_MST);
+
+ i2cp->rxbuf[i2cp->rxidx++] = i2c->D;
+
+ if (i2cp->rxidx == i2cp->rxbytes)
+ i2cp->intstate = STATE_STOP;
+ }
+
+ /* Reset interrupt flag */
+ i2c->S |= I2Cx_S_IICIF;
+
+ if (i2cp->errors != I2C_NO_ERROR)
+ _i2c_wakeup_error_isr(i2cp);
+
+ if (i2cp->intstate == STATE_STOP)
+ _i2c_wakeup_isr(i2cp);
+}
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+
+#if KINETIS_I2C_USE_I2C0 || defined(__DOXYGEN__)
+
+OSAL_IRQ_HANDLER(KINETIS_I2C0_IRQ_VECTOR) {
+
+ OSAL_IRQ_PROLOGUE();
+ serve_interrupt(&I2CD1);
+ OSAL_IRQ_EPILOGUE();
+}
+
+#endif
+
+#if KINETIS_I2C_USE_I2C1 || defined(__DOXYGEN__)
+
+OSAL_IRQ_HANDLER(KINETIS_I2C1_IRQ_VECTOR) {
+
+ OSAL_IRQ_PROLOGUE();
+ serve_interrupt(&I2CD2);
+ OSAL_IRQ_EPILOGUE();
+}
+
+#endif
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level I2C driver initialization.
+ *
+ * @notapi
+ */
+void i2c_lld_init(void) {
+
+#if KINETIS_I2C_USE_I2C0
+ i2cObjectInit(&I2CD1);
+ I2CD1.thread = NULL;
+ I2CD1.i2c = I2C0;
+#endif
+
+#if KINETIS_I2C_USE_I2C1
+ i2cObjectInit(&I2CD2);
+ I2CD2.thread = NULL;
+ I2CD2.i2c = I2C1;
+#endif
+
+}
+
+/**
+ * @brief Configures and activates the I2C peripheral.
+ *
+ * @param[in] i2cp pointer to the @p I2CDriver object
+ *
+ * @notapi
+ */
+void i2c_lld_start(I2CDriver *i2cp) {
+
+ if (i2cp->state == I2C_STOP) {
+
+ /* TODO:
+ * The PORT must be enabled somewhere. The PIN multiplexer
+ * will map the I2C functionality to some PORT which must
+ * than be enabled. The easier way is enabling all PORTs at
+ * startup, which is currently being done in __early_init.
+ */
+
+#if KINETIS_I2C_USE_I2C0
+ if (&I2CD1 == i2cp) {
+ SIM->SCGC4 |= SIM_SCGC4_I2C0;
+ nvicEnableVector(I2C0_IRQn, KINETIS_I2C_I2C0_PRIORITY);
+ }
+#endif
+
+#if KINETIS_I2C_USE_I2C1
+ if (&I2CD2 == i2cp) {
+ SIM->SCGC4 |= SIM_SCGC4_I2C1;
+ nvicEnableVector(I2C1_IRQn, KINETIS_I2C_I2C1_PRIORITY);
+ }
+#endif
+
+ }
+
+ config_frequency(i2cp);
+ i2cp->i2c->C1 |= I2Cx_C1_IICEN | I2Cx_C1_IICIE;
+ i2cp->intstate = STATE_STOP;
+}
+
+/**
+ * @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) {
+
+ i2cp->i2c->C1 &= ~(I2Cx_C1_IICEN | I2Cx_C1_IICIE);
+
+#if KINETIS_I2C_USE_I2C0
+ if (&I2CD1 == i2cp) {
+ SIM->SCGC4 &= ~SIM_SCGC4_I2C0;
+ nvicDisableVector(I2C0_IRQn);
+ }
+#endif
+
+#if KINETIS_I2C_USE_I2C1
+ if (&I2CD2 == i2cp) {
+ SIM->SCGC4 &= ~SIM_SCGC4_I2C1;
+ nvicDisableVector(I2C1_IRQn);
+ }
+#endif
+
+ }
+}
+
+static inline msg_t _i2c_txrx_timeout(I2CDriver *i2cp, i2caddr_t addr,
+ const uint8_t *txbuf, size_t txbytes,
+ uint8_t *rxbuf, size_t rxbytes,
+ systime_t timeout) {
+
+ (void)timeout;
+ msg_t msg;
+
+ uint8_t op = (i2cp->intstate == STATE_SEND) ? 0 : 1;
+
+ 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;
+
+ /* send START */
+ i2cp->i2c->C1 |= I2Cx_C1_MST;
+ i2cp->i2c->C1 |= I2Cx_C1_TX;
+
+ /* FIXME: should not use busy waiting! */
+ while (!(i2cp->i2c->S & I2Cx_S_BUSY));
+
+ i2cp->i2c->D = addr << 1 | op;
+
+ msg = osalThreadSuspendTimeoutS(&i2cp->thread, TIME_INFINITE);
+
+ /* FIXME */
+ //if (i2cp->i2c->S & I2Cx_S_RXAK)
+ // i2cp->errors |= I2C_ACK_FAILURE;
+
+ if (msg == MSG_OK && txbuf != NULL && rxbuf != NULL) {
+ i2cp->i2c->C1 |= I2Cx_C1_RSTA;
+ /* FIXME */
+ while (!(i2cp->i2c->S & I2Cx_S_BUSY));
+
+ i2cp->intstate = STATE_DUMMY;
+ i2cp->i2c->D = i2cp->addr << 1 | 1;
+
+ msg = osalThreadSuspendTimeoutS(&i2cp->thread, TIME_INFINITE);
+ }
+
+ i2cp->i2c->C1 &= ~(I2Cx_C1_TX | I2Cx_C1_MST);
+ /* FIXME */
+ while (i2cp->i2c->S & I2Cx_S_BUSY);
+
+ return msg;
+}
+
+/**
+ * @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->intstate = STATE_DUMMY;
+ return _i2c_txrx_timeout(i2cp, addr, NULL, 0, rxbuf, rxbytes, timeout);
+}
+
+/**
+ * @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->intstate = STATE_SEND;
+ return _i2c_txrx_timeout(i2cp, addr, txbuf, txbytes, rxbuf, rxbytes, timeout);
+}
+
+#endif /* HAL_USE_I2C */
+
+/** @} */
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