mbed library sources modified for open wear
Dependents: openwear-lifelogger-example
Fork of mbed-src by
Diff: targets/hal/TARGET_Freescale/TARGET_KPSDK_MCUS/i2c_api.c
- Revision:
- 265:9632ea190e16
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/hal/TARGET_Freescale/TARGET_KPSDK_MCUS/i2c_api.c Wed Jul 23 21:15:06 2014 +0100 @@ -0,0 +1,331 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2013 ARM Limited + * + * 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. + */ +#include "mbed_assert.h" +#include "i2c_api.h" + +#include "cmsis.h" +#include "pinmap.h" +#include "fsl_clock_manager.h" +#include "fsl_i2c_hal.h" +#include "fsl_port_hal.h" +#include "fsl_sim_hal.h" + +static const PinMap PinMap_I2C_SDA[] = { + {PTE25, I2C_0, 5}, + {PTB1 , I2C_0, 2}, + {PTB3 , I2C_0, 2}, + {PTC11, I2C_1, 2}, + {PTA13, I2C_2, 5}, + {PTD3 , I2C_0, 7}, + {PTE0 , I2C_1, 6}, + {NC , NC , 0} +}; + +static const PinMap PinMap_I2C_SCL[] = { + {PTE24, I2C_0, 5}, + {PTB0 , I2C_0, 2}, + {PTB2 , I2C_0, 2}, + {PTC10, I2C_1, 2}, + {PTA12, I2C_2, 5}, + {PTA14, I2C_2, 5}, + {PTD2 , I2C_0, 7}, + {PTE1 , I2C_1, 6}, + {NC , NC , 0} +}; + +void i2c_init(i2c_t *obj, PinName sda, PinName scl) { + uint32_t i2c_sda = pinmap_peripheral(sda, PinMap_I2C_SDA); + uint32_t i2c_scl = pinmap_peripheral(scl, PinMap_I2C_SCL); + obj->instance = pinmap_merge(i2c_sda, i2c_scl); + MBED_ASSERT((int)obj->instance != NC); + + clock_manager_set_gate(kClockModuleI2C, obj->instance, true); + clock_manager_set_gate(kClockModulePORT, sda >> GPIO_PORT_SHIFT, true); + clock_manager_set_gate(kClockModulePORT, scl >> GPIO_PORT_SHIFT, true); + i2c_hal_enable(obj->instance); + i2c_frequency(obj, 100000); + + pinmap_pinout(sda, PinMap_I2C_SDA); + pinmap_pinout(scl, PinMap_I2C_SCL); + port_hal_configure_open_drain(sda >> GPIO_PORT_SHIFT, sda & 0xFF, true); + port_hal_configure_open_drain(scl >> GPIO_PORT_SHIFT, scl & 0xFF, true); +} + +int i2c_start(i2c_t *obj) { + i2c_hal_send_start(obj->instance); + return 0; +} + +int i2c_stop(i2c_t *obj) { + volatile uint32_t n = 0; + i2c_hal_send_stop(obj->instance); + + // It seems that there are timing problems + // when there is no waiting time after a STOP. + // This wait is also included on the samples + // code provided with the freedom board + for (n = 0; n < 200; n++) __NOP(); + return 0; +} + +static int timeout_status_poll(i2c_t *obj, uint32_t mask) { + uint32_t i, timeout = 100000; + + for (i = 0; i < timeout; i++) { + if (HW_I2C_S_RD(obj->instance) & mask) + return 0; + } + return 1; +} + +// this function waits the end of a tx transfer and return the status of the transaction: +// 0: OK ack received +// 1: OK ack not received +// 2: failure +static int i2c_wait_end_tx_transfer(i2c_t *obj) { + // wait for the interrupt flag + if (timeout_status_poll(obj, I2C_S_IICIF_MASK)) { + return 2; + } + + i2c_hal_clear_interrupt(obj->instance); + + // wait transfer complete + if (timeout_status_poll(obj, I2C_S_TCF_MASK)) { + return 2; + } + + // check if we received the ACK or not + return i2c_hal_get_receive_ack(obj->instance) ? 0 : 1; +} + +// this function waits the end of a rx transfer and return the status of the transaction: +// 0: OK +// 1: failure +static int i2c_wait_end_rx_transfer(i2c_t *obj) { + // wait for the end of the rx transfer + if (timeout_status_poll(obj, I2C_S_IICIF_MASK)) { + return 1; + } + + i2c_hal_clear_interrupt(obj->instance); + + return 0; +} + +static int i2c_do_write(i2c_t *obj, int value) { + i2c_hal_write(obj->instance, value); + + // init and wait the end of the transfer + return i2c_wait_end_tx_transfer(obj); +} + +static int i2c_do_read(i2c_t *obj, char * data, int last) { + if (last) { + i2c_hal_send_nak(obj->instance); + } else { + i2c_hal_send_ack(obj->instance); + } + + *data = (i2c_hal_read(obj->instance) & 0xFF); + + // start rx transfer and wait the end of the transfer + return i2c_wait_end_rx_transfer(obj); +} + +void i2c_frequency(i2c_t *obj, int hz) { + uint32_t busClock; + + clock_manager_error_code_t error = clock_manager_get_frequency(kBusClock, &busClock); + if (error == kClockManagerSuccess) { + i2c_hal_set_baud(obj->instance, busClock, hz / 1000, NULL); + } +} + +int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) { + int count; + char dummy_read, *ptr; + + if (i2c_start(obj)) { + i2c_stop(obj); + return I2C_ERROR_BUS_BUSY; + } + + if (i2c_do_write(obj, (address | 0x01))) { + i2c_stop(obj); + return I2C_ERROR_NO_SLAVE; + } + + // set rx mode + i2c_hal_set_direction(obj->instance, kI2CReceive); + + // Read in bytes + for (count = 0; count < (length); count++) { + ptr = (count == 0) ? &dummy_read : &data[count - 1]; + uint8_t stop_ = (count == (length - 1)) ? 1 : 0; + if (i2c_do_read(obj, ptr, stop_)) { + i2c_stop(obj); + return count; + } + } + + // If not repeated start, send stop. + if (stop) + i2c_stop(obj); + + // last read + data[count-1] = i2c_hal_read(obj->instance); + + return length; +} + +int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop) { + int i; + + if (i2c_start(obj)) { + i2c_stop(obj); + return I2C_ERROR_BUS_BUSY; + } + + if (i2c_do_write(obj, (address & 0xFE))) { + i2c_stop(obj); + return I2C_ERROR_NO_SLAVE; + } + + for (i = 0; i < length; i++) { + if(i2c_do_write(obj, data[i])) { + i2c_stop(obj); + return i; + } + } + + if (stop) + i2c_stop(obj); + + return length; +} + +void i2c_reset(i2c_t *obj) { + i2c_stop(obj); +} + +int i2c_byte_read(i2c_t *obj, int last) { + char data; + + // set rx mode + i2c_hal_set_direction(obj->instance, kI2CReceive); + + // Setup read + i2c_do_read(obj, &data, last); + + // set tx mode + i2c_hal_set_direction(obj->instance, kI2CTransmit); + return i2c_hal_read(obj->instance); +} + +int i2c_byte_write(i2c_t *obj, int data) { + // set tx mode + i2c_hal_set_direction(obj->instance, kI2CTransmit); + + return !i2c_do_write(obj, (data & 0xFF)); +} + + +#if DEVICE_I2CSLAVE +void i2c_slave_mode(i2c_t *obj, int enable_slave) { + if (enable_slave) { + // set slave mode + BW_I2C_C1_MST(obj->instance, 0); + i2c_hal_enable_interrupt(obj->instance); + } else { + // set master mode + BW_I2C_C1_MST(obj->instance, 1); + } +} + +int i2c_slave_receive(i2c_t *obj) { + switch(HW_I2C_S_RD(obj->instance)) { + // read addressed + case 0xE6: + return 1; + // write addressed + case 0xE2: + return 3; + default: + return 0; + } +} + +int i2c_slave_read(i2c_t *obj, char *data, int length) { + uint8_t dummy_read; + uint8_t *ptr; + int count; + + // set rx mode + i2c_hal_set_direction(obj->instance, kI2CTransmit); + + // first dummy read + dummy_read = i2c_hal_read(obj->instance); + if (i2c_wait_end_rx_transfer(obj)) + return 0; + + // read address + dummy_read = i2c_hal_read(obj->instance); + if (i2c_wait_end_rx_transfer(obj)) + return 0; + + // read (length - 1) bytes + for (count = 0; count < (length - 1); count++) { + data[count] = i2c_hal_read(obj->instance); + if (i2c_wait_end_rx_transfer(obj)) + return count; + } + + // read last byte + ptr = (length == 0) ? &dummy_read : (uint8_t *)&data[count]; + *ptr = i2c_hal_read(obj->instance); + + return (length) ? (count + 1) : 0; +} + +int i2c_slave_write(i2c_t *obj, const char *data, int length) { + int i, count = 0; + + // set tx mode + i2c_hal_set_direction(obj->instance, kI2CTransmit); + + for (i = 0; i < length; i++) { + if (i2c_do_write(obj, data[count++]) == 2) + return i; + } + + // set rx mode + i2c_hal_set_direction(obj->instance, kI2CReceive); + + // dummy rx transfer needed + // otherwise the master cannot generate a stop bit + i2c_hal_read(obj->instance); + if (i2c_wait_end_rx_transfer(obj) == 2) + return count; + + return count; +} + +void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask) { + i2c_hal_set_upper_slave_address_7bit(obj->instance, address & 0xfe); +} +#endif +