diff options
| -rw-r--r-- | CODECONVENTIONS.md | 48 | ||||
| -rw-r--r-- | stm/i2c.c | 223 |
2 files changed, 161 insertions, 110 deletions
diff --git a/CODECONVENTIONS.md b/CODECONVENTIONS.md new file mode 100644 index 0000000000..a0e0fc7ab2 --- /dev/null +++ b/CODECONVENTIONS.md @@ -0,0 +1,48 @@ +Code conventions +================ + +When writing new code, please adhere to the following conventions. + +White space: +- Expand tabs to 4 spaces. +- Don't leave trailing whitespace at the end of a line. +- For control blocks (if, for, while), put 1 space between the + keyword and the opening parenthesis. +- Put 1 space after a comma, and 1 space around operators. + +Braces: +- Use braces for all blocks, even no-line and single-line pieces of + code. +- Put opening braces on the end of the line it belongs to, not on + a new line. +- For else-statements, put the else on the same line as the previous + closing brace. + +Include directives: +- Don't include within a header file. + +Type names and declarations: +- When defining a type, put '_t' after it. + +Examples +-------- + +Braces and spaces: + + int foo(int x, int y) { + if (x < y) { + foo(y, x); + } else { + foo(x + 1, y - 1); + } + + for (int i = 0; i < x; i++) { + } + } + +Type declarations: + + typedef struct _my_struct_t { + int member; + void *data; + } my_struct_t; @@ -15,75 +15,78 @@ typedef enum { } pyb_i2c_t; typedef enum { - I2C_STATE_IDLE = 0, - I2C_STATE_WRITE = 1, - I2C_STATE_READ = 2, + 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; +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) -{ +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 + I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); + if (i2c == NULL) + return false; - // 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); + if (i2c_port == PYB_I2C_1) { + if (i2c1_port_initialized == true) { + return true; + } + RCC->APB1ENR |= RCC_APB1ENR_I2C1EN; // enable I2C1 - // alternate functions for SCL and SDA - GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_I2C1); - GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_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 + i2c1_port_initialized = true; + } - // 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); + if (i2c_port == PYB_I2C_2) { + if (i2c2_port_initialized == true) { + return true; + } + RCC->APB1ENR |= RCC_APB1ENR_I2C2EN; // enable I2C2 - // alternate functions for SCL and SDA - GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_I2C2); - GPIO_PinAFConfig(GPIOB, GPIO_PinSource11, GPIO_AF_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; - } + i2c2_port_initialized = true; + } // get clock speeds RCC_ClocksTypeDef rcc_clocks; @@ -105,14 +108,13 @@ static bool _i2c_init (pyb_i2c_t i2c_port) // enable the I2C peripheral i2c->CR1 |= I2C_CR1_PE; - - return true; + 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; + I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); + if (i2c == NULL) return 0; uint32_t sr1 = i2c->SR1; uint32_t sr2 = i2c->SR2; @@ -120,8 +122,8 @@ static uint32_t _i2c_get_sr(pyb_i2c_t i2c_port) { } 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; + I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); + if (i2c == NULL) return false; // send start condition i2c->CR1 |= I2C_CR1_START; @@ -162,8 +164,8 @@ static bool _i2c_restart(pyb_i2c_t i2c_port, uint8_t addr, int write) { } 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; + I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); + if (i2c == NULL) return false; // send byte i2c->DR = data; @@ -179,8 +181,8 @@ static bool _i2c_send_byte(pyb_i2c_t i2c_port, uint8_t data) { } static uint8_t _i2c_read_ack(pyb_i2c_t i2c_port) { - I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); - if (i2c == NULL) return 0; + I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); + if (i2c == NULL) return 0; // enable ACK of received byte i2c->CR1 |= I2C_CR1_ACK; @@ -198,8 +200,8 @@ static uint8_t _i2c_read_ack(pyb_i2c_t i2c_port) { } static uint8_t _i2c_read_nack(pyb_i2c_t i2c_port) { - I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); - if (i2c == NULL) return 0; + 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); @@ -219,8 +221,8 @@ static uint8_t _i2c_read_nack(pyb_i2c_t i2c_port) { } static bool _i2c_start(pyb_i2c_t i2c_port) { - I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); - if (i2c == NULL) return false; + I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); + if (i2c == NULL) return false; // wait until I2C is not busy uint32_t timeout = 1000000; @@ -233,8 +235,8 @@ static bool _i2c_start(pyb_i2c_t i2c_port) { } static void _i2c_stop(pyb_i2c_t i2c_port) { - I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); - if (i2c == NULL) return; + I2C_TypeDef *i2c = _i2c_port_addr(i2c_port); + if (i2c == NULL) return; // send stop condition i2c->CR1 |= I2C_CR1_STOP; @@ -259,62 +261,62 @@ void i2c_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp 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; + _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_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; + 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); + 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); + 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; + _i2c_stop(self->i2c_port); + self->i2c_state = I2C_STATE_IDLE; return mp_const_none; } @@ -335,9 +337,9 @@ static const mp_obj_type_t i2c_obj_type = { NULL, // iternext { // method list { "start", &i2c_obj_start_obj }, - { "write", &i2c_obj_write_obj }, - { "read", &i2c_obj_read_obj }, - { "readAndStop", &i2c_obj_readAndStop_obj }, + { "write", &i2c_obj_write_obj }, + { "read", &i2c_obj_read_obj }, + { "readAndStop", &i2c_obj_readAndStop_obj }, { "stop", &i2c_obj_stop_obj }, { NULL, NULL }, } @@ -347,14 +349,15 @@ static const mp_obj_type_t i2c_obj_type = { // 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_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; |