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-rw-r--r--stm/i2c.c364
1 files changed, 0 insertions, 364 deletions
diff --git a/stm/i2c.c b/stm/i2c.c
deleted file mode 100644
index 011362cb5b..0000000000
--- a/stm/i2c.c
+++ /dev/null
@@ -1,364 +0,0 @@
-#include <stdio.h>
-
-#include <stm32f4xx.h>
-
-#include "misc.h"
-#include "systick.h"
-#include "mpconfig.h"
-#include "qstr.h"
-#include "obj.h"
-
-typedef enum {
- PYB_I2C_1 = 0,
- PYB_I2C_2 = 1,
-} pyb_i2c_t;
-
-typedef enum {
- I2C_STATE_IDLE = 0,
- I2C_STATE_WRITE = 1,
- I2C_STATE_READ = 2,
-} i2c_state_t;
-
-// set to true if the port has already been initialized
-bool i2c1_port_initialized = false;
-bool i2c2_port_initialized = false;
-
-static I2C_TypeDef * _i2c_port_addr(pyb_i2c_t i2c_port) {
- if (i2c_port == PYB_I2C_1) {
- return I2C1;
- }
- if (i2c_port == PYB_I2C_2) {
- return I2C2;
- }
- return NULL;
-}
-
-// todo - perhaps there should be some global resource management for gpio
-// this function would fail if the i2c pins have already been defined for
-// use by another python object
-// as it is, this always returns true (unless i2c_port is invalid)
-static bool _i2c_init(pyb_i2c_t i2c_port) {
- GPIO_InitTypeDef GPIO_InitStructure;
-
- I2C_TypeDef *i2c = _i2c_port_addr(i2c_port);
- if (i2c == NULL)
- return false;
-
- if (i2c_port == PYB_I2C_1) {
- if (i2c1_port_initialized == true) {
- return true;
- }
- RCC->APB1ENR |= RCC_APB1ENR_I2C1EN; // enable I2C1
-
- // PB6=SCL, PB7=SDA
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
- GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_25MHz;
- GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
- GPIO_Init(GPIOB, &GPIO_InitStructure);
-
- // alternate functions for SCL and SDA
- GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_I2C1);
- GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_I2C1);
-
-
- i2c1_port_initialized = true;
- }
-
- if (i2c_port == PYB_I2C_2) {
- if (i2c2_port_initialized == true) {
- return true;
- }
- RCC->APB1ENR |= RCC_APB1ENR_I2C2EN; // enable I2C2
-
- // PB10=SCL, PB11=SDA
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
- GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_25MHz;
- GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
- GPIO_Init(GPIOB, &GPIO_InitStructure);
-
- // alternate functions for SCL and SDA
- GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_I2C2);
- GPIO_PinAFConfig(GPIOB, GPIO_PinSource11, GPIO_AF_I2C2);
-
- i2c2_port_initialized = true;
- }
-
- // get clock speeds
- RCC_ClocksTypeDef rcc_clocks;
- RCC_GetClocksFreq(&rcc_clocks);
-
- // disable the I2C peripheral before we configure it
- i2c->CR1 &= ~I2C_CR1_PE;
-
- // program peripheral input clock
- i2c->CR2 = 4; // no interrupts; 4 MHz (hopefully!) (could go up to 42MHz)
-
- // configure clock control reg
- uint32_t freq = rcc_clocks.PCLK1_Frequency / (100000 << 1); // want 100kHz, this is the formula for freq
- i2c->CCR = freq; // standard mode (speed), freq calculated as above
-
- // configure rise time reg
- i2c->TRISE = (rcc_clocks.PCLK1_Frequency / 1000000) + 1; // formula for trise, gives maximum rise time
-
- // enable the I2C peripheral
- i2c->CR1 |= I2C_CR1_PE;
-
- return true;
-}
-
-static uint32_t _i2c_get_sr(pyb_i2c_t i2c_port) {
- // must read SR1 first, then SR2, as the read can clear some flags
- I2C_TypeDef *i2c = _i2c_port_addr(i2c_port);
- if (i2c == NULL) return 0;
-
- uint32_t sr1 = i2c->SR1;
- uint32_t sr2 = i2c->SR2;
- return (sr2 << 16) | sr1;
-}
-
-static bool _i2c_restart(pyb_i2c_t i2c_port, uint8_t addr, int write) {
- I2C_TypeDef *i2c = _i2c_port_addr(i2c_port);
- if (i2c == NULL) return false;
-
- // send start condition
- i2c->CR1 |= I2C_CR1_START;
-
- // wait for BUSY, MSL and SB --> Slave has acknowledged start condition
- uint32_t timeout = 1000000;
- while ((_i2c_get_sr(i2c_port) & 0x00030001) != 0x00030001) {
- if (--timeout == 0) {
- //printf("timeout in _i2c_restart\n");
- return false;
- }
- }
-
- if (write) {
- // send address and write bit
- i2c->DR = (addr << 1) | 0;
- // wait for BUSY, MSL, ADDR, TXE and TRA
- timeout = 1000000;
- while ((_i2c_get_sr(i2c_port) & 0x00070082) != 0x00070082) {
- if (--timeout == 0) {
- //printf("timeout in _i2c_restart write\n");
- return false;
- }
- }
- } else {
- // send address and read bit
- i2c->DR = (addr << 1) | 1;
- // wait for BUSY, MSL and ADDR flags
- timeout = 1000000;
- while ((_i2c_get_sr(i2c_port) & 0x00030002) != 0x00030002) {
- if (--timeout == 0) {
- //printf("timeout in _i2c_restart read\n");
- return false;
- }
- }
- }
- return true;
-}
-
-static bool _i2c_send_byte(pyb_i2c_t i2c_port, uint8_t data) {
- I2C_TypeDef *i2c = _i2c_port_addr(i2c_port);
- if (i2c == NULL) return false;
-
- // send byte
- i2c->DR = data;
- // wait for TRA, BUSY, MSL, TXE and BTF (byte transmitted)
- uint32_t timeout = 1000000;
- while ((_i2c_get_sr(i2c_port) & 0x00070084) != 0x00070084) {
- if (--timeout == 0) {
- //printf("timeout in _i2c_send_byte\n");
- return false;
- }
- }
- return true;
-}
-
-static uint8_t _i2c_read_ack(pyb_i2c_t i2c_port) {
- I2C_TypeDef *i2c = _i2c_port_addr(i2c_port);
- if (i2c == NULL) return 0;
-
- // enable ACK of received byte
- i2c->CR1 |= I2C_CR1_ACK;
- // wait for BUSY, MSL and RXNE (byte received)
- uint32_t timeout = 1000000;
- while ((_i2c_get_sr(i2c_port) & 0x00030040) != 0x00030040) {
- if (--timeout == 0) {
- //printf("timeout in _i2c_read_ack\n");
- break;
- }
- }
- // read and return data
- uint8_t data = i2c->DR;
- return data;
-}
-
-static uint8_t _i2c_read_nack(pyb_i2c_t i2c_port) {
- I2C_TypeDef *i2c = _i2c_port_addr(i2c_port);
- if (i2c == NULL) return 0;
-
- // disable ACK of received byte (to indicate end of receiving)
- i2c->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_ACK);
- // last byte should apparently also generate a stop condition
- i2c->CR1 |= I2C_CR1_STOP;
- // wait for BUSY, MSL and RXNE (byte received)
- uint32_t timeout = 1000000;
- while ((_i2c_get_sr(i2c_port) & 0x00030040) != 0x00030040) {
- if (--timeout == 0) {
- //printf("timeout in _i2c_read_nack\n");
- break;
- }
- }
- // read and return data
- uint8_t data = i2c->DR;
- return data;
-}
-
-static bool _i2c_start(pyb_i2c_t i2c_port) {
- I2C_TypeDef *i2c = _i2c_port_addr(i2c_port);
- if (i2c == NULL) return false;
-
- // wait until I2C is not busy
- uint32_t timeout = 1000000;
- while (i2c->SR2 & I2C_SR2_BUSY) {
- if (--timeout == 0) {
- return false;
- }
- }
- return true;
-}
-
-static void _i2c_stop(pyb_i2c_t i2c_port) {
- I2C_TypeDef *i2c = _i2c_port_addr(i2c_port);
- if (i2c == NULL) return;
-
- // send stop condition
- i2c->CR1 |= I2C_CR1_STOP;
-}
-
-/******************************************************************************/
-/* Micro Python bindings */
-
-typedef struct _pyb_i2c_obj_t {
- mp_obj_base_t base;
- pyb_i2c_t i2c_port;
- int i2c_addr;
- i2c_state_t i2c_state;
-} pyb_i2c_obj_t;
-
-void i2c_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
- pyb_i2c_obj_t *self = self_in;
- print(env, "<I2C%lu addr:%lu>", (unsigned int)self->i2c_port, (unsigned int)self->i2c_addr);
-}
-
-// calls _i2c_start with write=0,1 depending on LSB of i2c_addr
-mp_obj_t i2c_obj_start(mp_obj_t self_in) {
- pyb_i2c_obj_t *self = self_in;
- if (self->i2c_state != I2C_STATE_IDLE) {
- _i2c_stop(self->i2c_port);
- self->i2c_state = I2C_STATE_IDLE;
- }
- if (_i2c_start(self->i2c_port) == true)
- return mp_const_true;
- return mp_const_false;
-}
-
-mp_obj_t i2c_obj_write(mp_obj_t self_in, mp_obj_t data_in) {
- pyb_i2c_obj_t *self = self_in;
- if (self->i2c_state != I2C_STATE_WRITE) {
- if (_i2c_restart(self->i2c_port, self->i2c_addr, 1) == false) {
- _i2c_stop(self->i2c_port);
- self->i2c_state = I2C_STATE_IDLE;
- return mp_const_false;
- }
- self->i2c_state = I2C_STATE_WRITE;
- }
- uint8_t data = mp_obj_get_int(data_in);
- if (_i2c_send_byte(self->i2c_port, data) == false)
- return mp_const_false;
- return mp_const_true;
-}
-
-mp_obj_t i2c_obj_read(mp_obj_t self_in) {
- pyb_i2c_obj_t *self = self_in;
- if (self->i2c_state != I2C_STATE_READ) {
- if (_i2c_restart(self->i2c_port, self->i2c_addr, 0) == false) {
- _i2c_stop(self->i2c_port);
- self->i2c_state = I2C_STATE_IDLE;
- return mp_const_false;
- }
- self->i2c_state = I2C_STATE_READ;
- }
- uint8_t data = _i2c_read_ack(self->i2c_port);
- return mp_obj_new_int(data);
-}
-
-mp_obj_t i2c_obj_readAndStop(mp_obj_t self_in) {
- pyb_i2c_obj_t *self = self_in;
- if (self->i2c_state != I2C_STATE_READ) {
- if (_i2c_restart(self->i2c_port, self->i2c_addr, 0) == false) {
- _i2c_stop(self->i2c_port);
- self->i2c_state = I2C_STATE_IDLE;
- return mp_const_false;
- }
- }
- uint8_t data = _i2c_read_nack(self->i2c_port);
- self->i2c_state = I2C_STATE_IDLE;
- return mp_obj_new_int(data);
-}
-
-mp_obj_t i2c_obj_stop(mp_obj_t self_in) {
- pyb_i2c_obj_t *self = self_in;
- _i2c_stop(self->i2c_port);
- self->i2c_state = I2C_STATE_IDLE;
- return mp_const_none;
-}
-
-static MP_DEFINE_CONST_FUN_OBJ_1(i2c_obj_start_obj, i2c_obj_start);
-static MP_DEFINE_CONST_FUN_OBJ_2(i2c_obj_write_obj, i2c_obj_write);
-static MP_DEFINE_CONST_FUN_OBJ_1(i2c_obj_read_obj, i2c_obj_read);
-static MP_DEFINE_CONST_FUN_OBJ_1(i2c_obj_readAndStop_obj, i2c_obj_readAndStop);
-static MP_DEFINE_CONST_FUN_OBJ_1(i2c_obj_stop_obj, i2c_obj_stop);
-
-STATIC const mp_map_elem_t i2c_locals_dict_table[] = {
- { MP_OBJ_NEW_QSTR(MP_QSTR_start), (mp_obj_t)&i2c_obj_start_obj },
- { MP_OBJ_NEW_QSTR(MP_QSTR_write), (mp_obj_t)&i2c_obj_write_obj },
- { MP_OBJ_NEW_QSTR(MP_QSTR_read), (mp_obj_t)&i2c_obj_read_obj },
- { MP_OBJ_NEW_QSTR(MP_QSTR_readAndStop), (mp_obj_t)&i2c_obj_readAndStop_obj },
- { MP_OBJ_NEW_QSTR(MP_QSTR_stop), (mp_obj_t)&i2c_obj_stop_obj },
-};
-
-STATIC MP_DEFINE_CONST_DICT(i2c_locals_dict, i2c_locals_dict_table);
-
-static const mp_obj_type_t i2c_obj_type = {
- { &mp_type_type },
- .name = MP_QSTR_I2C,
- .print = i2c_obj_print,
- .locals_dict = (mp_obj_t)&i2c_locals_dict,
-};
-
-// create the I2C object
-// currently support either I2C1 (i2c_id = 0) or I2C2 (i2c_id = 1)
-
-mp_obj_t pyb_I2C(mp_obj_t i2c_id, mp_obj_t i2c_addr) {
- pyb_i2c_t i2c_port;
- switch(mp_obj_get_int(i2c_id)) {
- case 0: i2c_port = PYB_I2C_1; break;
- case 1: i2c_port = PYB_I2C_2; break;
- default: return mp_const_none;
- }
- if (_i2c_init(i2c_port) == false) {
- return mp_const_none;
- }
- pyb_i2c_obj_t *o = m_new_obj(pyb_i2c_obj_t);
- o->base.type = &i2c_obj_type;
- o->i2c_port = i2c_port;
- o->i2c_addr = mp_obj_get_int(i2c_addr);
- o->i2c_state = I2C_STATE_IDLE;
- return o;
-}
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