Lesson mpu6050

04-mpu6050/Makefile

@@ -0,0 +1,14 @@
+obj-m := mpu6050.o
+KERNELDIR=/home/danilpetrov/Kernel
+export ARCH = arm
+export CROSS_COMPILE ?= arm-linux-gnueabihf-
+
+
+.PHONY: all clean
+
+all:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
+
+clean:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) clean
+

04-mpu6050/README.md

@@ -1,3 +1,11 @@
 # MPU6050 Practice. Kernel object module development
 
 ## Homework
+
+1. Create simplest driver (kernel object module) using compiled kernel (by Armbian or without it)  
+	and cross-compiler.
+2. Fix errors in driver mpu6050 from repository.
+3. Сompile it using cross-compiler.
+4. Deploy and run it. Check output using dmesg.
+5. Check modified DTS.
+6. Check driver’s output by reading value from sysfs

04-mpu6050/moduleMpu6050.c

@@ -0,0 +1,276 @@
+#include <linux/module.h>
+#include "mpu6050_reg.h"
+#include <linux/version.h>
+#include <linux/proc_fs.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/kdev_t.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/i2c-dev.h>
+#define DISCHARGE 1000
+#define SIXTEEN 65536
+
+
+struct mpu6050_data {
+    struct i2c_client *drv_client;
+    int accel_values[3];
+    int gyro_values[3];
+    int temperatureC[2];
+    int temperatureF[2];
+};
+
+static struct mpu6050_data gl_mpu6050_data;
+static struct class *class_device;
+
+static ssize_t accel_x_show(struct class *class, struct class_attribute *attr, char *buf);
+static ssize_t accel_y_show(struct class *class, struct class_attribute *attr, char *buf);
+static ssize_t accel_z_show(struct class *class, struct class_attribute *attr, char *buf);
+static ssize_t gyro_x_show(struct class *class, struct class_attribute *attr, char *buf);
+static ssize_t gyro_y_show(struct class *class, struct class_attribute *attr, char *buf);
+static ssize_t gyro_z_show(struct class *class, struct class_attribute *attr, char *buf);
+static ssize_t temperature_show(struct class *class, struct class_attribute *attr, char *buf);
+
+struct class_attribute accel_x_attr = __ATTR(ACCEL_X, 0444, &accel_x_show, NULL);
+struct class_attribute accel_y_attr = __ATTR(ACCEL_Y, 0444, &accel_y_show, NULL);
+struct class_attribute accel_z_attr = __ATTR(ACCEL_Z, 0444, &accel_z_show, NULL);
+
+struct class_attribute gyro_x_attr = __ATTR(GYRO_X, 0444, &gyro_x_show, NULL);
+struct class_attribute gyro_y_attr = __ATTR(GYRO_Y, 0444, &gyro_y_show, NULL);
+struct class_attribute gyro_z_attr = __ATTR(GYRO_Z, 0444, &gyro_z_show, NULL);
+
+struct class_attribute temperature_attr = __ATTR(TEMP, 0444, &temperature_show, NULL);
+
+static ssize_t accel_x_show(struct class *class, struct class_attribute *attr, char *buf)
+{
+    uint8_t h;
+    uint8_t l;
+    uint16_t t;
+    h = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_ACCEL_XOUT_H);
+    l = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_ACCEL_XOUT_L);
+    t = (h << 8 | l);
+    gl_mpu6050_data.accel_values[0] = (t & 0x7fff) - (t & 0x8000);
+    printk(KERN_INFO  "Accel_X: [%d]\n", gl_mpu6050_data.accel_values[0]);
+    sprintf(buf, "Accel_X: [%d]\n", gl_mpu6050_data.accel_values[0]);
+    return strlen(buf);
+}
+static ssize_t accel_y_show(struct class *class, struct class_attribute *attr, char *buf)
+{
+    uint8_t h;
+    uint8_t l;
+    uint16_t t;
+    h = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_ACCEL_YOUT_H);
+    l = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_ACCEL_YOUT_L);
+    t = (h << 8 | l);
+    gl_mpu6050_data.accel_values[1] = (t & 0x7fff) - (t & 0x8000);
+    printk(KERN_INFO  "Accel_Y: [%d]\n", gl_mpu6050_data.accel_values[1]);
+    sprintf(buf, "Accel_Y: [%d]\n", gl_mpu6050_data.accel_values[1]);
+    return strlen(buf);
+}
+static ssize_t accel_z_show(struct class *class, struct class_attribute *attr, char *buf)
+{
+    uint8_t h;
+    uint8_t l;
+    uint16_t t;
+    h = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_ACCEL_ZOUT_H);
+    l = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_ACCEL_ZOUT_L);
+    t = (h << 8 | l);
+    gl_mpu6050_data.accel_values[2] = (t & 0x7fff) - (t & 0x8000);
+    printk(KERN_INFO  "Accel_Z: [%d]\n", gl_mpu6050_data.accel_values[2]);
+    sprintf(buf, "Accel_Z: [%d]\n", gl_mpu6050_data.accel_values[2]);
+    return strlen(buf);
+
+}
+static ssize_t gyro_x_show(struct class *class, struct class_attribute *attr, char *buf)
+{
+    uint8_t h;
+    uint8_t l;
+    uint16_t t;
+    h = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_GYRO_XOUT_H);
+    l = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_GYRO_XOUT_L);
+    t = (h << 8 | l);
+    gl_mpu6050_data.gyro_values[0] = (t & 0x7fff) - (t & 0x8000);
+    printk(KERN_INFO  "Gyro_X: [%d]\n", gl_mpu6050_data.gyro_values[0]);
+    sprintf(buf, "Gyro_X: [%d]\n", gl_mpu6050_data.gyro_values[0]);
+    return strlen(buf);
+}
+static ssize_t gyro_y_show(struct class *class, struct class_attribute *attr, char *buf)
+{
+    uint8_t h;
+    uint8_t l;
+    uint16_t t;
+    h = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_GYRO_YOUT_H);
+    l = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_GYRO_YOUT_L);
+    t = (h << 8 | l);
+    gl_mpu6050_data.gyro_values[1] = (t & 0x7fff) - (t & 0x8000);
+    printk(KERN_INFO  "Gyro_Y: [%d]\n", gl_mpu6050_data.gyro_values[1]);
+    sprintf(buf, "Gyro_Y: [%d]\n", gl_mpu6050_data.gyro_values[1]);
+    return strlen(buf);
+}
+static ssize_t gyro_z_show(struct class *class, struct class_attribute *attr, char *buf)
+{
+    uint8_t h;
+    uint8_t l;
+    uint16_t t;
+    h = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_GYRO_ZOUT_H);
+    l = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_GYRO_ZOUT_L);
+    t = (h << 8 | l);
+    gl_mpu6050_data.gyro_values[2] = (t & 0x7fff) - (t & 0x8000);
+    printk(KERN_INFO  "Gyro_Z: [%d]\n", gl_mpu6050_data.gyro_values[2]);
+    sprintf(buf, "Gyro_Z: [%d]\n", gl_mpu6050_data.gyro_values[2]);
+    return strlen(buf);
+}
+static ssize_t temperature_show(struct class *class, struct class_attribute *attr, char *buf)
+{
+    uint8_t h;
+    uint8_t l;
+    uint16_t t;
+    int result;
+    printk(KERN_INFO "Show_Temperature\n");
+    h = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_TEMP_OUT_H);
+    l = i2c_smbus_read_byte_data(gl_mpu6050_data.drv_client, REG_TEMP_OUT_L);
+    t = (h << 8 | l);
+    result = ((t & 0x7fff) - (t & 0x8000));
+    result = result*DISCHARGE/340 + 12420*DISCHARGE/340;
+    gl_mpu6050_data.temperatureC[0] = result / DISCHARGE;
+    gl_mpu6050_data.temperatureC[1] = result % DISCHARGE;
+    gl_mpu6050_data.temperatureF[0] = ((result*9/5)+32*DISCHARGE)/DISCHARGE;
+    gl_mpu6050_data.temperatureF[1] = ((result*9/5)+32*DISCHARGE) % DISCHARGE;
+    printk(KERN_INFO  "Temperature: %d.%03d C\n", gl_mpu6050_data.temperatureC[0], gl_mpu6050_data.temperatureC[1]);
+    printk(KERN_INFO  "Temperature: %d.%03d F\n", gl_mpu6050_data.temperatureF[0], gl_mpu6050_data.temperatureF[1]);
+    sprintf(buf,"Temperature: %d.%03d C\nTemperature: %d.%03d F\n", gl_mpu6050_data.temperatureC[0], gl_mpu6050_data.temperatureC[1], gl_mpu6050_data.temperatureF[0], gl_mpu6050_data.temperatureF[1]);
+    return strlen(buf);
+}
+
+static int mpu6050_probe(struct i2c_client *drv_client, const struct i2c_device_id *id)
+{
+    int ret;
+    dev_info(&drv_client->dev, "i2c driver probed\n");
+    dev_info(&drv_client->dev, "i2c client address is 0x%X\n", drv_client->addr);
+
+    ret = i2c_smbus_read_byte_data(drv_client, REG_WHO_AM_I);
+    if (IS_ERR_VALUE(ret)) {
+        dev_err(&drv_client->dev, "i2c_smbus_read_byte_data() failed with error: %d\n", ret);
+        return ret;
+    }
+    if (ret != MPU6050_WHO_AM_I) {
+        dev_err(&drv_client->dev, "wrong i2c device found: expected 0x%X, found 0x%X\n", MPU6050_WHO_AM_I, ret);
+        return -1;
+    }
+    dev_info(&drv_client->dev, "i2c mpu6050 device found, WHO_AM_I register value = 0x%X\n", ret);
+
+    i2c_smbus_write_byte_data(drv_client, REG_CONFIG, 0);
+    i2c_smbus_write_byte_data(drv_client, REG_GYRO_CONFIG, 0);
+    i2c_smbus_write_byte_data(drv_client, REG_ACCEL_CONFIG, 0);
+    i2c_smbus_write_byte_data(drv_client, REG_FIFO_EN, 0);
+    i2c_smbus_write_byte_data(drv_client, REG_INT_PIN_CFG, 0);
+    i2c_smbus_write_byte_data(drv_client, REG_INT_ENABLE, 0);
+    i2c_smbus_write_byte_data(drv_client, REG_USER_CTRL, 0);
+    i2c_smbus_write_byte_data(drv_client, REG_PWR_MGMT_1, 0);
+    i2c_smbus_write_byte_data(drv_client, REG_PWR_MGMT_2, 0);
+
+    gl_mpu6050_data.drv_client = drv_client;
+    return 0;
+}
+
+static int mpu6050_remove(struct i2c_client *drv_client)
+{
+    dev_info(&drv_client->dev, "i2c driver remove\n");
+    gl_mpu6050_data.drv_client = 0;
+    return 0;
+}
+
+static const struct i2c_device_id mpu6050_id[] = {
+    { "mpu6050", 0 },
+    { }
+};
+
+MODULE_DEVICE_TABLE(i2c, mpu6050_id);
+
+static struct i2c_driver mpu6050_i2c_driver = {
+    .driver = {
+        .name = "gl_mpu6050",
+    },
+    .probe = mpu6050_probe,
+    .remove = mpu6050_remove,
+    .id_table = mpu6050_id,
+};
+static int mpu6050_init(void)
+{
+    int ret;
+    ret = i2c_add_driver(&mpu6050_i2c_driver);
+    printk(KERN_INFO "mpu6050: module add\n");
+
+    if ((class_device = class_create(THIS_MODULE, NAME_SYSCLASS)) < 0) {
+        printk(KERN_ERR "Mpu6050: Error with create class_create.\n");
+        return -ENOMEM;
+    }
+    ret = class_create_file(class_device, &accel_x_attr);
+    if (ret < 0) {
+        printk(KERN_ERR "Mpu6050: Error wih create file accel_x_attr.\n");
+        return -ENOMEM;
+    }
+    ret = class_create_file(class_device, &accel_y_attr);
+    if (ret < 0) {
+        printk(KERN_ERR "Mpu6050: Error wih create file accel_y_attr.\n");
+        return -ENOMEM;
+    }
+    ret = class_create_file(class_device, &accel_z_attr);
+    if (ret < 0) {
+        printk(KERN_ERR "Mpu6050: Error wih create file accel_z_attr.\n");
+        return -ENOMEM;
+    }
+    ret = class_create_file(class_device, &gyro_x_attr);
+    if (ret < 0) {
+        printk(KERN_ERR "Mpu6050: Error wih create file gyro_x_attr.\n");
+        return -ENOMEM;
+    }
+    ret = class_create_file(class_device, &gyro_y_attr);
+    if (ret < 0) {
+        printk(KERN_ERR "Mpu6050: Error wih create file gyro_y_attr.\n");
+        return -ENOMEM;
+    }
+    ret = class_create_file(class_device, &gyro_z_attr);
+    if (ret < 0) {
+        printk(KERN_ERR "Mpu6050: Error wih create file gyro_z_attr.\n");
+        return -ENOMEM;
+    }
+    ret = class_create_file(class_device, &temperature_attr);
+    if (ret < 0) {
+        printk(KERN_ERR "Mpu6050: Error wih create file temperature_attrs.\n");
+        return -ENOMEM;
+    }
+    return 0;
+}
+
+static void mpu6050_exit(void)
+{
+
+    i2c_del_driver(&mpu6050_i2c_driver);
+    printk(KERN_INFO "mpu6050: module del\n");
+    class_remove_file(class_device, &accel_x_attr);
+    class_remove_file(class_device, &accel_y_attr);
+    class_remove_file(class_device, &accel_z_attr);
+    class_remove_file(class_device, &gyro_x_attr);
+    class_remove_file(class_device, &gyro_y_attr);
+    class_remove_file(class_device, &gyro_z_attr);
+    class_remove_file(class_device, &temperature_attr);
+    class_destroy(class_device);
+}
+
+module_init(mpu6050_init);
+module_exit(mpu6050_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Danil Petrov <[email protected]>");
+MODULE_DESCRIPTION("My module for mpu6050 on GY-521");
+MODULE_VERSION("0.1");
+
+

04-mpu6050/mpu6050_reg.h

@@ -0,0 +1,43 @@
+#ifndef _MPU6050_REG_H
+#define _MPU6050_REG_H
+
+#define REG_CONFIG            0x1A
+#define REG_GYRO_CONFIG       0x1B
+#define REG_ACCEL_CONFIG      0x1C
+#define REG_FIFO_EN           0x23
+#define REG_INT_PIN_CFG       0x37
+#define REG_INT_ENABLE        0x38
+#define REG_ACCEL_XOUT_H      0x3B
+#define REG_ACCEL_XOUT_L      0x3C
+#define REG_ACCEL_YOUT_H      0x3D
+#define REG_ACCEL_YOUT_L      0x3E
+#define REG_ACCEL_ZOUT_H      0x3F
+#define REG_ACCEL_ZOUT_L      0x40
+#define REG_TEMP_OUT_H        0x41
+#define REG_TEMP_OUT_L        0x42
+#define REG_GYRO_XOUT_H       0x43
+#define REG_GYRO_XOUT_L       0x44
+#define REG_GYRO_YOUT_H       0x45
+#define REG_GYRO_YOUT_L       0x46
+#define REG_GYRO_ZOUT_H       0x47
+#define REG_GYRO_ZOUT_L       0x48
+#define REG_USER_CTRL         0x6A
+#define REG_PWR_MGMT_1        0x6B
+#define REG_PWR_MGMT_2        0x6C
+#define REG_WHO_AM_I          0x75
+
+#define MPU6050_WHO_AM_I      0x68
+#define ACCEL_X accel_x
+#define ACCEL_Y accel_y
+#define ACCEL_Z accel_z
+
+#define GYRO_X gyro_x
+#define GYRO_Y gyro_y
+#define GYRO_Z gyro_z
+
+#define TEMP Temperature
+
+#define NAME_SYSCLASS "Mpu6050"
+#endif
+
+