diff options
Diffstat (limited to 'os/hal/platforms/LPC11xx/i2c_lld.c')
| -rw-r--r-- | os/hal/platforms/LPC11xx/i2c_lld.c | 438 |
1 files changed, 438 insertions, 0 deletions
diff --git a/os/hal/platforms/LPC11xx/i2c_lld.c b/os/hal/platforms/LPC11xx/i2c_lld.c new file mode 100644 index 000000000..c68f11460 --- /dev/null +++ b/os/hal/platforms/LPC11xx/i2c_lld.c @@ -0,0 +1,438 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio
+ LPC11xx I2C driver - Copyright (C) 2013 Marcin Jokel
+
+ 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.
+*/
+
+/*
+ Concepts and parts of this file have been contributed by Uladzimir Pylinsky
+ aka barthess.
+ */
+
+
+/**
+ * @file LPC11xx/i2c_lld.h
+ * @brief LPC11xx I2C subsystem low level driver header.
+ *
+ * @addtogroup I2C
+ * @{
+ */
+
+#include "ch.h"
+#include "hal.h"
+
+#if HAL_USE_I2C || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver local definitions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver constants. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+/** @brief I2C1 driver identifier.*/
+I2CDriver I2CD1;
+
+/*===========================================================================*/
+/* Driver local variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Wakes up the waiting thread.
+ *
+ * @param[in] i2cp pointer to the @p I2CDriver object
+ * @param[in] msg wakeup message
+ *
+ * @notapi
+ */
+#define wakeup_isr(i2cp, msg) { \
+ chSysLockFromIsr(); \
+ if ((i2cp)->thread != NULL) { \
+ Thread *tp = (i2cp)->thread; \
+ (i2cp)->thread = NULL; \
+ tp->p_u.rdymsg = (msg); \
+ chSchReadyI(tp); \
+ } \
+ chSysUnlockFromIsr(); \
+}
+
+/**
+ * @brief Handling of stalled I2C transactions.
+ *
+ * @param[in] i2cp pointer to the @p I2CDriver object
+ *
+ * @notapi
+ */
+static void i2c_lld_safety_timeout(void *p) {
+ I2CDriver *i2cp = (I2CDriver *)p;
+
+ chSysLockFromIsr();
+ if (i2cp->thread) {
+ Thread *tp = i2cp->thread;
+ i2cp->thread = NULL;
+ tp->p_u.rdymsg = RDY_TIMEOUT;
+ chSchReadyI(tp);
+ }
+ chSysUnlockFromIsr();
+}
+
+/**
+ * @brief I2C error handler.
+ *
+ * @param[in] i2cp pointer to the @p I2CDriver object
+ *
+ * @notapi
+ */
+static void i2c_lld_serve_error_interrupt(I2CDriver *i2cp, uint32_t status) {
+ i2cflags_t error = 0;
+
+ switch (status) {
+ case I2C_STATE_ARB_LOST:
+ error = I2CD_ARBITRATION_LOST;
+ break;
+ case I2C_STATE_BUS_ERROR:
+ error = I2CD_BUS_ERROR;
+ break;
+ case I2C_STATE_MS_SLAR_NACK:
+ case I2C_STATE_MS_TDAT_NACK:
+ case I2C_STATE_MS_SLAW_NACK:
+ error = I2CD_ACK_FAILURE ;
+ break;
+ }
+
+ /* If some error has been identified then sends wakes the waiting thread.*/
+ i2cp->errors = error;
+ wakeup_isr(i2cp, RDY_RESET);
+}
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+/**
+ * @brief I2C event interrupt handler.
+ *
+ * @notapi
+ */
+CH_IRQ_HANDLER(Vector7C) {
+ uint32_t status;
+
+ CH_IRQ_PROLOGUE();
+ status = LPC_I2C->STAT;
+ switch(status) {
+ case I2C_STATE_MS_START: /* A START condition has been transmitted. */
+ if (I2CD1.txbytes > 0) {
+ LPC_I2C->DAT = I2CD1.addr; /* Write slave address with WR bit. */
+ }
+ else {
+ LPC_I2C->DAT = I2CD1.addr | I2C_RD_BIT; /* Write slave address with RD bit. */
+ }
+
+ LPC_I2C->CONCLR = I2C_CONCLR_STAC | I2C_CONCLR_SIC; /* Clear START and SI bit. */
+ break;
+
+ case I2C_STATE_MS_SLAR_NACK: /* NOT ACK has been received, Master will be transmitted STOP. */
+ case I2C_STATE_MS_TDAT_NACK: /* NOT ACK has been received, Master will be transmitted STOP. */
+ case I2C_STATE_MS_SLAW_NACK: /* NOT ACK has been received, Master will be transmitted STOP. */
+ LPC_I2C->CONSET = I2C_CONSET_STO; /* Set STOP bit. */
+ LPC_I2C->CONCLR = I2C_CONCLR_SIC; /* Clear SI bit. */
+ i2c_lld_serve_error_interrupt(&I2CD1, status);
+ break;
+
+ case I2C_STATE_MS_SLAW_ACK: /* SLA + W has been transmitted, ACK has been received. */
+ case I2C_STATE_MS_TDAT_ACK: /* Data byte has been transmitted, ACK has been received. */
+ if (I2CD1.txbytes > 0) {
+ LPC_I2C->DAT = *I2CD1.txbuf++; /* Write data. */
+ I2CD1.txbytes--;
+ }
+ else {
+ if (I2CD1.rxbytes > 0) {
+ LPC_I2C->CONSET = I2C_CONSET_STO | I2C_CONSET_STA; /* Set START and STOP bit. */
+ } /* STOP bit will be transmit, then START bit. */
+ else {
+ LPC_I2C->CONSET = I2C_CONSET_STO; /* Set STOP bit. */
+ wakeup_isr(&I2CD1, RDY_OK);
+ }
+ }
+ LPC_I2C->CONCLR = I2C_CONCLR_SIC; /* Clear SI bit. */
+ break;
+
+ case I2C_STATE_MS_SLAR_ACK: /* SLA + R has been transmitted, ACK has been received. */
+ case I2C_STATE_MS_RDAT_ACK: /* Data byte has been received, ACK has been returned. */
+ if (status == I2C_STATE_MS_RDAT_ACK) {
+ *I2CD1.rxbuf++ = LPC_I2C->DAT; /* Read data */
+ I2CD1.rxbytes--;
+ }
+ if (I2CD1.rxbytes == 1) {
+ LPC_I2C->CONCLR = I2C_CONCLR_SIC | I2C_CONCLR_AAC; /* Clear SI and ACK bit. */
+ }
+ else {
+ LPC_I2C->CONSET = I2C_CONSET_AA; /* Set ACK bit. */
+ LPC_I2C->CONCLR = I2C_CONCLR_SIC; /* Clear SI bit. */
+ }
+ break;
+
+ case I2C_STATE_MS_RDAT_NACK: /* Data byte has been received, NOT ACK has been returned. */
+ *I2CD1.rxbuf++ = LPC_I2C->DAT; /* Read data. */
+ I2CD1.rxbytes--;
+ LPC_I2C->CONSET = I2C_CONSET_STO; /* Set STOP bit. */
+ LPC_I2C->CONCLR = I2C_CONCLR_SIC; /* Clear SI bit. */
+ wakeup_isr(&I2CD1, RDY_OK);
+ break;
+
+ case I2C_STATE_BUS_ERROR: /* Bus error. */
+ case I2C_STATE_ARB_LOST: /* Arbitration lost. */
+ LPC_I2C->CONCLR = I2C_CONCLR_SIC; /* Clear SI bit. */
+ i2c_lld_serve_error_interrupt(&I2CD1, status);
+ break;
+
+ }
+
+ CH_IRQ_EPILOGUE();
+}
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level I2C driver initialization.
+ *
+ * @notapi
+ */
+void i2c_lld_init(void) {
+
+ i2cObjectInit(&I2CD1);
+ I2CD1.thread = NULL;
+ I2CD1.i2c = LPC_I2C;
+
+ LPC_IOCON->PIO0_4 = 0x01; /* Set I2C SCL pin function */
+ LPC_IOCON->PIO0_5 = 0x01; /* Set I2C SDA pin function */
+}
+
+/**
+ * @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 i2cscl;
+ uint32_t mulh, mull, div;
+ LPC_I2C_TypeDef *dp = i2cp->i2c;
+
+ /* Make sure I2C peripheral is disabled */
+ dp->CONCLR = I2C_CONCLR_ENC;
+
+ /* If in stopped state then enables the I2C clock. */
+ if (i2cp->state == I2C_STOP) {
+
+ if (&I2CD1 == i2cp) {
+ LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 5); /* Enable clock. */
+ LPC_SYSCON->PRESETCTRL &= ~(1 << 1); /* Reset I2C peripheral.*/
+ __NOP();
+ LPC_SYSCON->PRESETCTRL |= (1 << 1);
+ nvicEnableVector(I2C_IRQn,
+ CORTEX_PRIORITY_MASK(LPC11xx_I2C_IRQ_PRIORITY));
+ }
+
+ }
+
+ /* Setup I2C clock parameters.*/
+ i2cscl = (LPC11xx_SYSCLK/(i2cp->config->clock_timing));
+ if (i2cp->config->mode == I2C_FAST_MODE) {
+ div = 19;
+ mull = 13;
+ mulh = 6;
+ } else if (i2cp->config->mode == I2C_FAST_MODE_PLUS) {
+ div = 3;
+ mull = 2;
+ mulh = 1;
+ } else { /* i2cp->config->mode == I2C_STANDARD_MODE */
+ div = 2;
+ mull = 1;
+ mulh = 1;
+ }
+
+ dp->SCLH = (mulh * i2cscl) / div;
+ dp->SCLL = (mull * i2cscl) / div;
+
+ /* Enable I2C.*/
+ dp->CONSET |= I2C_CONSET_EN;
+}
+
+/**
+ * @brief Deactivates the I2C peripheral.
+ *
+ * @param[in] i2cp pointer to the @p I2CDriver object
+ *
+ * @notapi
+ */
+void i2c_lld_stop(I2CDriver *i2cp) {
+
+ /* If not in stopped state then disables the I2C clock.*/
+ if (i2cp->state != I2C_STOP) {
+
+ /* I2C disable.*/
+ i2cp->i2c->CONCLR = I2C_CONCLR_ENC;
+
+ if (&I2CD1 == i2cp) {
+ nvicDisableVector(I2C_IRQn);
+ LPC_SYSCON->SYSAHBCLKCTRL &= ~(1 << 5);
+ }
+ }
+}
+
+/**
+ * @brief Receives data via the I2C bus as master.
+ * @details Number of receiving bytes must be more than 1 on STM32F1x. This is
+ * hardware restriction.
+ *
+ * @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 RDY_OK if the function succeeded.
+ * @retval RDY_RESET if one or more I2C errors occurred, the errors can
+ * be retrieved using @p i2cGetErrors().
+ * @retval RDY_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) {
+ LPC_I2C_TypeDef *dp = i2cp->i2c;
+ VirtualTimer vt;
+
+ i2cp->addr = addr << 1;
+ /* Global timeout for the whole operation.*/
+ if (timeout != TIME_INFINITE)
+ chVTSetI(&vt, timeout, i2c_lld_safety_timeout, (void *)i2cp);
+
+ /* Releases the lock from high level driver.*/
+ chSysUnlock();
+
+ /* Initializes driver fields */
+ i2cp->errors = 0;
+ i2cp->rxbuf = rxbuf;
+ i2cp->rxbytes = rxbytes;
+
+ /* This lock will be released in high level driver.*/
+ chSysLock();
+
+ /* Atomic check on the timer in order to make sure that a timeout didn't
+ happen outside the critical zone.*/
+ if ((timeout != TIME_INFINITE) && !chVTIsArmedI(&vt))
+ return RDY_TIMEOUT;
+
+ /* Starts the operation.*/
+ dp->CONSET = I2C_CONSET_STA;
+
+ /* Waits for the operation completion or a timeout.*/
+ i2cp->thread = chThdSelf();
+ chSchGoSleepS(THD_STATE_SUSPENDED);
+ if ((timeout != TIME_INFINITE) && chVTIsArmedI(&vt))
+ chVTResetI(&vt);
+
+ return chThdSelf()->p_u.rdymsg;
+}
+
+/**
+ * @brief Transmits data via the I2C bus as master.
+ * @details Number of receiving bytes must be 0 or more than 1 on STM32F1x.
+ * This is hardware restriction.
+ *
+ * @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 RDY_OK if the function succeeded.
+ * @retval RDY_RESET if one or more I2C errors occurred, the errors can
+ * be retrieved using @p i2cGetErrors().
+ * @retval RDY_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) {
+ LPC_I2C_TypeDef *dp = i2cp->i2c;
+ VirtualTimer vt;
+
+ i2cp->addr = addr << 1;
+ /* Global timeout for the whole operation.*/
+ if (timeout != TIME_INFINITE)
+ chVTSetI(&vt, timeout, i2c_lld_safety_timeout, (void *)i2cp);
+
+ /* Releases the lock from high level driver.*/
+ chSysUnlock();
+
+ /* Initializes driver fields */
+ i2cp->errors = 0;
+ i2cp->txbuf = txbuf;
+ i2cp->txbytes = txbytes;
+ i2cp->rxbuf = rxbuf;
+ i2cp->rxbytes = rxbytes;
+
+ /* This lock will be released in high level driver.*/
+ chSysLock();
+
+ /* Atomic check on the timer in order to make sure that a timeout didn't
+ happen outside the critical zone.*/
+ if ((timeout != TIME_INFINITE) && !chVTIsArmedI(&vt))
+ return RDY_TIMEOUT;
+
+ /* Starts the operation.*/
+ dp->CONSET = I2C_CONSET_STA;
+
+ /* Waits for the operation completion or a timeout.*/
+ i2cp->thread = chThdSelf();
+ chSchGoSleepS(THD_STATE_SUSPENDED);
+
+ if ((timeout != TIME_INFINITE) && chVTIsArmedI(&vt))
+ chVTResetI(&vt);
+
+ return chThdSelf()->p_u.rdymsg;
+}
+
+#endif /* HAL_USE_I2C */
+
+/** @} */
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