stm: Rename mma -> accel.

1 files changed, 300 insertions, 0 deletions

diff --git a/stm/accel.c b/stm/accel.c
new file mode 100644
index 0000000000..ae9d588680
--- /dev/null
+++ b/stm/accel.c
@@ -0,0 +1,300 @@
+#include <stdio.h>
+
+#include <stm32f4xx.h>
+#include <stm32f4xx_rcc.h>
+#include <stm32f4xx_gpio.h>
+
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "systick.h"
+#include "obj.h"
+#include "runtime.h"
+#include "accel.h"
+
+#define ACCEL_ADDR (0x4c)
+
+void accel_init(void) {
+    RCC->APB1ENR |= RCC_APB1ENR_I2C1EN; // enable I2C1
+
+    //gpio_pin_init(GPIOB, 6 /* B6 is SCL */, 2 /* AF mode */, 1 /* open drain output */, 1 /* 25 MHz */, 0 /* no pull up or pull down */);
+    //gpio_pin_init(GPIOB, 7 /* B7 is SDA */, 2 /* AF mode */, 1 /* open drain output */, 1 /* 25 MHz */, 0 /* no pull up or pull down */);
+    //gpio_pin_af(GPIOB, 6, 4 /* AF 4 for I2C1 */);
+    //gpio_pin_af(GPIOB, 7, 4 /* AF 4 for I2C1 */);
+    // XXX untested GPIO init! (was above code)
+
+    GPIO_InitTypeDef GPIO_InitStructure;
+
+    // PB5 is connected to AVDD; pull high to enable MMA accel device
+    GPIOB->BSRRH = GPIO_Pin_5; // PB5 low to start with
+    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
+    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
+    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
+    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
+    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
+    GPIO_Init(GPIOB, &GPIO_InitStructure);
+
+    // 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);
+
+    // get clock speeds
+    RCC_ClocksTypeDef rcc_clocks;
+    RCC_GetClocksFreq(&rcc_clocks);
+
+    // disable the I2C peripheral before we configure it
+    I2C1->CR1 &= ~I2C_CR1_PE;
+
+    // program peripheral input clock
+    I2C1->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
+    I2C1->CCR = freq; // standard mode (speed), freq calculated as above
+
+    // configure rise time reg
+    I2C1->TRISE = (rcc_clocks.PCLK1_Frequency / 1000000) + 1; // formula for trise, gives maximum rise time
+
+    // enable the I2C peripheral
+    I2C1->CR1 |= I2C_CR1_PE;
+
+    // wait 20ms, then turn on AVDD, then wait 20ms again; this seems to work, but maybe can decrease delays
+    // doesn't work for soft reboot; 50ms doesn't work either...
+    sys_tick_delay_ms(20);
+    GPIOB->BSRRL = GPIO_Pin_5;
+    sys_tick_delay_ms(20);
+
+    // set START bit in CR1 to generate a start cond!
+
+    // init the chip via I2C commands
+    accel_start(ACCEL_ADDR, 1);
+    accel_send_byte(0);
+    accel_stop();
+
+    /*
+    // read and print all 11 registers
+    accel_start(ACCEL_ADDR, 1);
+    accel_send_byte(0);
+    accel_restart(ACCEL_ADDR, 0);
+    for (int i = 0; i <= 0xa; i++) {
+        int data;
+        if (i == 0xa) {
+            data = accel_read_nack();
+        } else {
+            data = accel_read_ack();
+        }
+        printf(" %02x", data);
+    }
+    printf("\n");
+    */
+
+    // put into active mode
+    accel_start(ACCEL_ADDR, 1);
+    accel_send_byte(7); // mode
+    accel_send_byte(1); // active mode
+    accel_stop();
+
+    /*
+    // infinite loop to read values
+    for (;;) {
+        sys_tick_delay_ms(500);
+
+        accel_start(ACCEL_ADDR, 1);
+        accel_send_byte(0);
+        accel_restart(ACCEL_ADDR, 0);
+        for (int i = 0; i <= 3; i++) {
+            int data;
+            if (i == 3) {
+                data = accel_read_nack();
+                printf(" %02x\n", data);
+            } else {
+                data = accel_read_ack() & 0x3f;
+                if (data & 0x20) {
+                    data |= ~0x1f;
+                }
+                printf(" % 2d", data);
+            }
+        }
+    }
+    */
+}
+
+static uint32_t i2c_get_sr(void) {
+    // must read SR1 first, then SR2, as the read can clear some flags
+    uint32_t sr1 = I2C1->SR1;
+    uint32_t sr2 = I2C1->SR2;
+    return (sr2 << 16) | sr1;
+}
+
+void accel_restart(uint8_t addr, int write) {
+    // send start condition
+    I2C1->CR1 |= I2C_CR1_START;
+
+    // wait for BUSY, MSL and SB --> Slave has acknowledged start condition
+    uint32_t timeout = 1000000;
+    while ((i2c_get_sr() & 0x00030001) != 0x00030001) {
+        if (--timeout == 0) {
+            printf("timeout in accel_restart\n");
+            return;
+        }
+    }
+
+    if (write) {
+        // send address and write bit
+        I2C1->DR = (addr << 1) | 0;
+        // wait for BUSY, MSL, ADDR, TXE and TRA
+        timeout = 1000000;
+        while ((i2c_get_sr() & 0x00070082) != 0x00070082) {
+            if (--timeout == 0) {
+                printf("timeout in accel_restart write\n");
+                return;
+            }
+        }
+    } else {
+        // send address and read bit
+        I2C1->DR = (addr << 1) | 1;
+        // wait for BUSY, MSL and ADDR flags
+        timeout = 1000000;
+        while ((i2c_get_sr() & 0x00030002) != 0x00030002) {
+            if (--timeout == 0) {
+                printf("timeout in accel_restart read\n");
+                return;
+            }
+        }
+    }
+}
+
+void accel_start(uint8_t addr, int write) {
+    // wait until I2C is not busy
+    uint32_t timeout = 1000000;
+    while (I2C1->SR2 & I2C_SR2_BUSY) {
+        if (--timeout == 0) {
+            printf("timeout in accel_start\n");
+            return;
+        }
+    }
+
+    // do rest of start
+    accel_restart(addr, write);
+}
+
+void accel_send_byte(uint8_t data) {
+    // send byte
+    I2C1->DR = data;
+    // wait for TRA, BUSY, MSL, TXE and BTF (byte transmitted)
+    uint32_t timeout = 1000000;
+    while ((i2c_get_sr() & 0x00070084) != 0x00070084) {
+        if (--timeout == 0) {
+            printf("timeout in accel_send_byte\n");
+            return;
+        }
+    }
+}
+
+uint8_t accel_read_ack(void) {
+    // enable ACK of received byte
+    I2C1->CR1 |= I2C_CR1_ACK;
+    // wait for BUSY, MSL and RXNE (byte received)
+    uint32_t timeout = 1000000;
+    while ((i2c_get_sr() & 0x00030040) != 0x00030040) {
+        if (--timeout == 0) {
+            printf("timeout in accel_read_ack\n");
+            break;
+        }
+    }
+    // read and return data
+    uint8_t data = I2C1->DR;
+    return data;
+}
+
+uint8_t accel_read_nack(void) {
+    // disable ACK of received byte (to indicate end of receiving)
+    I2C1->CR1 &= (uint16_t)~((uint16_t)I2C_CR1_ACK);
+    // last byte should apparently also generate a stop condition
+    I2C1->CR1 |= I2C_CR1_STOP;
+    // wait for BUSY, MSL and RXNE (byte received)
+    uint32_t timeout = 1000000;
+    while ((i2c_get_sr() & 0x00030040) != 0x00030040) {
+        if (--timeout == 0) {
+            printf("timeout in accel_read_nack\n");
+            break;
+        }
+    }
+    // read and return data
+    uint8_t data = I2C1->DR;
+    return data;
+}
+
+void accel_stop(void) {
+    // send stop condition
+    I2C1->CR1 |= I2C_CR1_STOP;
+}
+
+/******************************************************************************/
+/* Micro Python bindings                                                      */
+
+int accel_buf[12];
+
+mp_obj_t pyb_accel_read(void) {
+    for (int i = 0; i <= 6; i += 3) {
+        accel_buf[0 + i] = accel_buf[0 + i + 3];
+        accel_buf[1 + i] = accel_buf[1 + i + 3];
+        accel_buf[2 + i] = accel_buf[2 + i + 3];
+    }
+
+    accel_start(ACCEL_ADDR, 1);
+    accel_send_byte(0);
+    accel_restart(ACCEL_ADDR, 0);
+    for (int i = 0; i <= 2; i++) {
+        int v = accel_read_ack() & 0x3f;
+        if (v & 0x20) {
+            v |= ~0x1f;
+        }
+        accel_buf[9 + i] = v;
+    }
+    int jolt_info = accel_read_nack();
+
+    mp_obj_t data[4];
+    data[0] = mp_obj_new_int(accel_buf[0] + accel_buf[3] + accel_buf[6] + accel_buf[9]);
+    data[1] = mp_obj_new_int(accel_buf[1] + accel_buf[4] + accel_buf[7] + accel_buf[10]);
+    data[2] = mp_obj_new_int(accel_buf[2] + accel_buf[5] + accel_buf[8] + accel_buf[11]);
+    data[3] = mp_obj_new_int(jolt_info);
+
+    return rt_build_tuple(4, data);
+}
+
+MP_DEFINE_CONST_FUN_OBJ_0(pyb_accel_read_obj, pyb_accel_read);
+
+mp_obj_t pyb_accel_read_all(void) {
+    mp_obj_t data[11];
+    accel_start(ACCEL_ADDR, 1);
+    accel_send_byte(0);
+    accel_restart(ACCEL_ADDR, 0);
+    for (int i = 0; i <= 9; i++) {
+        data[i] = mp_obj_new_int(accel_read_ack());
+    }
+    data[10] = mp_obj_new_int(accel_read_nack());
+
+    return rt_build_tuple(11, data);
+}
+
+MP_DEFINE_CONST_FUN_OBJ_0(pyb_accel_read_all_obj, pyb_accel_read_all);
+
+mp_obj_t pyb_accel_write_mode(mp_obj_t o_int, mp_obj_t o_mode) {
+    accel_start(ACCEL_ADDR, 1);
+    accel_send_byte(6); // start at int
+    accel_send_byte(mp_obj_get_int(o_int));
+    accel_send_byte(mp_obj_get_int(o_mode));
+    accel_stop();
+    return mp_const_none;
+}
+
+MP_DEFINE_CONST_FUN_OBJ_2(pyb_accel_write_mode_obj, pyb_accel_write_mode);