stmhal: Add I2C support; change accel driver to use new I2C.

1 files changed, 184 insertions, 0 deletions

diff --git a/stmhal/i2c.c b/stmhal/i2c.c
new file mode 100644
index 0000000000..b8608ad3ba
--- /dev/null
+++ b/stmhal/i2c.c
@@ -0,0 +1,184 @@
+#include <stdio.h>
+#include <string.h>
+
+#include <stm32f4xx_hal.h>
+
+#include "nlr.h"
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "obj.h"
+#include "runtime.h"
+#include "i2c.h"
+
+I2C_HandleTypeDef I2cHandle_X;
+I2C_HandleTypeDef I2cHandle_Y;
+
+void i2c_init(void) {
+    // init the I2C1 device
+    memset(&I2cHandle_X, 0, sizeof(I2C_HandleTypeDef));
+    I2cHandle_X.Instance = I2C1;
+
+    // init the I2C2 device
+    memset(&I2cHandle_Y, 0, sizeof(I2C_HandleTypeDef));
+    I2cHandle_Y.Instance = I2C2;
+}
+
+void i2c_start(I2C_HandleTypeDef *i2c_handle) {
+    GPIO_InitTypeDef GPIO_InitStructure;
+
+    // init the GPIO lines
+    GPIO_InitStructure.Mode = GPIO_MODE_AF_OD;
+    GPIO_InitStructure.Speed = GPIO_SPEED_FAST;
+    GPIO_InitStructure.Pull = GPIO_NOPULL; // have external pull-up resistors on both lines
+
+    if (i2c_handle == &I2cHandle_X) {
+        // X-skin: X9=PB6=SCL, X10=PB7=SDA
+        GPIO_InitStructure.Pin = GPIO_PIN_6 | GPIO_PIN_7;
+        GPIO_InitStructure.Alternate = GPIO_AF4_I2C1;
+        HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);
+        // enable the I2C clock
+        __I2C1_CLK_ENABLE();
+    } else {
+        // Y-skin: Y9=PB10=SCL, Y10=PB11=SDA
+        GPIO_InitStructure.Pin = GPIO_PIN_10 | GPIO_PIN_11;
+        GPIO_InitStructure.Alternate = GPIO_AF4_I2C2;
+        HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);
+        // enable the I2C clock
+        __I2C2_CLK_ENABLE();
+    }
+
+    // init the I2C device
+    i2c_handle->Init.AddressingMode  = I2C_ADDRESSINGMODE_7BIT;
+    i2c_handle->Init.ClockSpeed      = 400000;
+    i2c_handle->Init.DualAddressMode = I2C_DUALADDRESS_DISABLED;
+    i2c_handle->Init.DutyCycle       = I2C_DUTYCYCLE_16_9;
+    i2c_handle->Init.GeneralCallMode = I2C_GENERALCALL_DISABLED;
+    i2c_handle->Init.NoStretchMode   = I2C_NOSTRETCH_DISABLED;
+    i2c_handle->Init.OwnAddress1     = 0xfe; // unused
+    i2c_handle->Init.OwnAddress2     = 0xfe; // unused
+
+    if (HAL_I2C_Init(i2c_handle) != HAL_OK) {
+        // init error
+        printf("accel_init: HAL_I2C_Init failed\n");
+        return;
+    }
+}
+
+/******************************************************************************/
+/* Micro Python bindings                                                      */
+
+#define PYB_NUM_I2C (2)
+
+typedef struct _pyb_i2c_obj_t {
+    mp_obj_base_t base;
+    I2C_HandleTypeDef *i2c_handle;
+} pyb_i2c_obj_t;
+
+STATIC pyb_i2c_obj_t pyb_i2c_obj[PYB_NUM_I2C] = {{{&pyb_i2c_type}, &I2cHandle_X}, {{&pyb_i2c_type}, &I2cHandle_Y}};
+
+STATIC mp_obj_t pyb_i2c_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
+    // check arguments
+    if (!(n_args == 1 && n_kw == 0)) {
+        nlr_jump(mp_obj_new_exception_msg(&mp_type_ValueError, "I2C accepts 1 argument"));
+    }
+
+    // get i2c number
+    machine_int_t i2c_id = mp_obj_get_int(args[0]) - 1;
+
+    // check i2c number
+    if (!(0 <= i2c_id && i2c_id < PYB_NUM_I2C)) {
+        nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "I2C bus %d does not exist", i2c_id + 1));
+    }
+
+    // get i2c object
+    pyb_i2c_obj_t *i2c_obj = &pyb_i2c_obj[i2c_id];
+
+    // start the peripheral
+    i2c_start(i2c_obj->i2c_handle);
+
+    return &pyb_i2c_obj;
+}
+
+STATIC mp_obj_t pyb_i2c_is_ready(mp_obj_t self_in, mp_obj_t i2c_addr_o) {
+    pyb_i2c_obj_t *self = self_in;
+    machine_uint_t i2c_addr = mp_obj_get_int(i2c_addr_o) << 1;
+
+    //printf("IsDeviceReady\n");
+    for (int i = 0; i < 10; i++) {
+        HAL_StatusTypeDef status = HAL_I2C_IsDeviceReady(self->i2c_handle, i2c_addr, 10, 200);
+        //printf("  got %d\n", status);
+        if (status == HAL_OK) {
+            return mp_const_true;
+        }
+    }
+
+    return mp_const_false;
+}
+
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_i2c_is_ready_obj, pyb_i2c_is_ready);
+
+STATIC mp_obj_t pyb_i2c_mem_read(uint n_args, const mp_obj_t *args) {
+    pyb_i2c_obj_t *self = args[0];
+    machine_uint_t i2c_addr = mp_obj_get_int(args[1]) << 1;
+    machine_uint_t mem_addr = mp_obj_get_int(args[2]);
+    machine_uint_t n = mp_obj_get_int(args[3]);
+
+    byte *data;
+    mp_obj_t o = mp_obj_str_builder_start(&bytes_type, n, &data);
+    HAL_StatusTypeDef status = HAL_I2C_Mem_Read(self->i2c_handle, i2c_addr, mem_addr, I2C_MEMADD_SIZE_8BIT, data, n, 200);
+
+    //printf("Read got %d\n", status);
+
+    if (status != HAL_OK) {
+        // TODO really need a HardwareError object, or something
+        nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_I2C_Mem_Read failed with code %d", status));
+    }
+
+    return mp_obj_str_builder_end(o);
+}
+
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_i2c_mem_read_obj, 4, 4, pyb_i2c_mem_read);
+
+STATIC mp_obj_t pyb_i2c_mem_write(uint n_args, const mp_obj_t *args) {
+    pyb_i2c_obj_t *self = args[0];
+    machine_uint_t i2c_addr = mp_obj_get_int(args[1]) << 1;
+    machine_uint_t mem_addr = mp_obj_get_int(args[2]);
+    HAL_StatusTypeDef status;
+    mp_obj_type_t *type = mp_obj_get_type(args[3]);
+    if (type->buffer_p.get_buffer != NULL) {
+        buffer_info_t bufinfo;
+        type->buffer_p.get_buffer(args[3], &bufinfo, BUFFER_READ);
+        status = HAL_I2C_Mem_Write(self->i2c_handle, i2c_addr, mem_addr, I2C_MEMADD_SIZE_8BIT, bufinfo.buf, bufinfo.len, 200);
+    } else if (MP_OBJ_IS_INT(args[3])) {
+        uint8_t data[1] = {mp_obj_get_int(args[3])};
+        status = HAL_I2C_Mem_Write(self->i2c_handle, i2c_addr, mem_addr, I2C_MEMADD_SIZE_8BIT, data, 1, 200);
+    } else {
+        nlr_jump(mp_obj_new_exception_msg(&mp_type_TypeError, "data argument must be an integer or support the buffer protocol"));
+    }
+
+    //printf("Write got %d\n", status);
+
+    if (status != HAL_OK) {
+        // TODO really need a HardwareError object, or something
+        nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_I2C_Mem_Write failed with code %d", status));
+    }
+
+    return mp_const_none;
+}
+
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_i2c_mem_write_obj, 4, 4, pyb_i2c_mem_write);
+
+STATIC const mp_method_t pyb_i2c_methods[] = {
+    { "is_ready", &pyb_i2c_is_ready_obj },
+    { "mem_read", &pyb_i2c_mem_read_obj },
+    { "mem_write", &pyb_i2c_mem_write_obj },
+    { NULL, NULL },
+};
+
+const mp_obj_type_t pyb_i2c_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_I2C,
+    .make_new = pyb_i2c_make_new,
+    .methods = pyb_i2c_methods,
+};