10-ConcurrencyAndSynchronization: Add base driver for mpu6050

Signed-off-by: Bekir <[email protected]>
Kernel-GL-HRK · Dec 17, 2019 · c420a6b · c420a6b
1 parent 925cbef
commit c420a6b
Show file tree

Hide file tree

Showing 3 changed files with 341 additions and 0 deletions.
diff --git a/10-ConcurrencyAndSynchronization/Makefile b/10-ConcurrencyAndSynchronization/Makefile
@@ -0,0 +1,12 @@
+obj-m += mpu6050.o
+
+KERNEL_DIR :=  /home/bekir/Work/LinuxKernelCamp/linux/linux-stable
+
+COMPILE_FLAGS += CROSS_COMPILE=arm-linux-gnueabihf- CROSS=arm-linux-gnueabihf- ARCH=arm
+
+all:
+		make -C $(KERNEL_DIR) M=$(PWD) $(COMPILE_FLAGS) modules
+clean:
+		make -C $(KERNEL_DIR) M=$(PWD) $(COMPILE_FLAGS) clean
+install:
+		make -C $(KERNEL_DIR) M=$(PWD) modules_install INSTALL_MOD_PATH=$(PWD)/build_modules
diff --git a/10-ConcurrencyAndSynchronization/mpu6050-regs.h b/10-ConcurrencyAndSynchronization/mpu6050-regs.h
@@ -0,0 +1,33 @@
+#ifndef _MPU6050_REGS_H
+#define _MPU6050_REGS_H
+
+/* Registed addresses */
+#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
+
+/* Register values */
+#define MPU6050_WHO_AM_I	0x68
+
+#endif /* _MPU6050_REGS_H */
diff --git a/10-ConcurrencyAndSynchronization/mpu6050.c b/10-ConcurrencyAndSynchronization/mpu6050.c
@@ -0,0 +1,296 @@
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/i2c-dev.h>
+
+#include "mpu6050-regs.h"
+
+
+struct mpu6050_data {
+	struct i2c_client *drv_client;
+	int accel_values[3];
+	int gyro_values[3];
+	int temperature;
+};
+
+static struct mpu6050_data g_mpu6050_data;
+
+static int mpu6050_read_data(void)
+{
+	int temp;
+	struct i2c_client *drv_client = g_mpu6050_data.drv_client;
+
+	if (drv_client == 0)
+		return -ENODEV;
+
+	/* accel */
+	g_mpu6050_data.accel_values[0] = (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_ACCEL_XOUT_H));
+	g_mpu6050_data.accel_values[1] = (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_ACCEL_YOUT_H));
+	g_mpu6050_data.accel_values[2] = (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_ACCEL_ZOUT_H));
+	/* gyro */
+	g_mpu6050_data.gyro_values[0] = (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_GYRO_XOUT_H));
+	g_mpu6050_data.gyro_values[1] = (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_GYRO_YOUT_H));
+	g_mpu6050_data.gyro_values[2] = (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_GYRO_ZOUT_H));
+	/* Temperature in degrees C =
+	 * (TEMP_OUT Register Value  as a signed quantity)/340 + 36.53
+	 */
+	temp = (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_TEMP_OUT_H));
+	g_mpu6050_data.temperature = (temp + 12420 + 170) / 340;
+
+	dev_info(&drv_client->dev, "sensor data read:\n");
+	dev_info(&drv_client->dev, "ACCEL[X,Y,Z] = [%d, %d, %d]\n",
+		g_mpu6050_data.accel_values[0],
+		g_mpu6050_data.accel_values[1],
+		g_mpu6050_data.accel_values[2]);
+	dev_info(&drv_client->dev, "GYRO[X,Y,Z] = [%d, %d, %d]\n",
+		g_mpu6050_data.gyro_values[0],
+		g_mpu6050_data.gyro_values[1],
+		g_mpu6050_data.gyro_values[2]);
+	dev_info(&drv_client->dev, "TEMP = %d\n",
+		g_mpu6050_data.temperature);
+
+	return 0;
+}
+
+static int mpu6050_probe(struct i2c_client *drv_client,
+			 const struct i2c_device_id *id)
+{
+	int ret;
+
+	dev_info(&drv_client->dev,
+		"i2c client address is 0x%X\n", drv_client->addr);
+
+	/* Read who_am_i register */
+	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);
+
+	/* Setup the device */
+	/* No error handling here! */
+	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);
+
+	g_mpu6050_data.drv_client = drv_client;
+
+	dev_info(&drv_client->dev, "i2c driver probed\n");
+	return 0;
+}
+
+static int mpu6050_remove(struct i2c_client *drv_client)
+{
+	g_mpu6050_data.drv_client = 0;
+
+	dev_info(&drv_client->dev, "i2c driver removed\n");
+	return 0;
+}
+
+static const struct i2c_device_id mpu6050_idtable[] = {
+	{ "mpu6050", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mpu6050_idtable);
+
+static struct i2c_driver mpu6050_i2c_driver = {
+	.driver = {
+		.name = "gl_mpu6050",
+	},
+
+	.probe = mpu6050_probe,
+	.remove = mpu6050_remove,
+	.id_table = mpu6050_idtable,
+};
+
+static ssize_t accel_x_show(struct class *class,
+			    struct class_attribute *attr, char *buf)
+{
+	mpu6050_read_data();
+
+	sprintf(buf, "%d\n", g_mpu6050_data.accel_values[0]);
+	return strlen(buf);
+}
+
+static ssize_t accel_y_show(struct class *class,
+			    struct class_attribute *attr, char *buf)
+{
+	mpu6050_read_data();
+
+	sprintf(buf, "%d\n", g_mpu6050_data.accel_values[1]);
+	return strlen(buf);
+}
+
+static ssize_t accel_z_show(struct class *class,
+			    struct class_attribute *attr, char *buf)
+{
+	mpu6050_read_data();
+
+	sprintf(buf, "%d\n", g_mpu6050_data.accel_values[2]);
+	return strlen(buf);
+}
+
+static ssize_t gyro_x_show(struct class *class,
+			   struct class_attribute *attr, char *buf)
+{
+	mpu6050_read_data();
+
+	sprintf(buf, "%d\n", g_mpu6050_data.gyro_values[0]);
+	return strlen(buf);
+}
+
+static ssize_t gyro_y_show(struct class *class,
+			   struct class_attribute *attr, char *buf)
+{
+	mpu6050_read_data();
+
+	sprintf(buf, "%d\n", g_mpu6050_data.gyro_values[1]);
+	return strlen(buf);
+}
+
+static ssize_t gyro_z_show(struct class *class,
+			   struct class_attribute *attr, char *buf)
+{
+	mpu6050_read_data();
+
+	sprintf(buf, "%d\n", g_mpu6050_data.gyro_values[2]);
+	return strlen(buf);
+}
+
+static ssize_t temp_show(struct class *class,
+			 struct class_attribute *attr, char *buf)
+{
+	mpu6050_read_data();
+
+	sprintf(buf, "%d\n", g_mpu6050_data.temperature);
+	return strlen(buf);
+}
+
+CLASS_ATTR(accel_x, 0444, &accel_x_show, NULL);
+CLASS_ATTR(accel_y, 0444, &accel_y_show, NULL);
+CLASS_ATTR(accel_z, 0444, &accel_z_show, NULL);
+CLASS_ATTR(gyro_x, 0444, &gyro_x_show, NULL);
+CLASS_ATTR(gyro_y, 0444, &gyro_y_show, NULL);
+CLASS_ATTR(gyro_z, 0444, &gyro_z_show, NULL);
+CLASS_ATTR(temperature, 0444, &temp_show, NULL);
+
+static struct class *attr_class;
+
+static int mpu6050_init(void)
+{
+	int ret;
+
+	/* Create i2c driver */
+	ret = i2c_add_driver(&mpu6050_i2c_driver);
+	if (ret) {
+		pr_err("mpu6050: failed to add new i2c driver: %d\n", ret);
+		return ret;
+	}
+	pr_info("mpu6050: i2c driver created\n");
+
+	/* Create class */
+	attr_class = class_create(THIS_MODULE, "mpu6050");
+	if (IS_ERR(attr_class)) {
+		ret = PTR_ERR(attr_class);
+		pr_err("mpu6050: failed to create sysfs class: %d\n", ret);
+		return ret;
+	}
+	pr_info("mpu6050: sysfs class created\n");
+
+	/* Create accel_x */
+	ret = class_create_file(attr_class, &class_attr_accel_x);
+	if (ret) {
+		pr_err("mpu6050: failed to create sysfs class attribute accel_x: %d\n", ret);
+		return ret;
+	}
+	/* Create accel_y */
+	ret = class_create_file(attr_class, &class_attr_accel_y);
+	if (ret) {
+		pr_err("mpu6050: failed to create sysfs class attribute accel_y: %d\n", ret);
+		return ret;
+	}
+	/* Create accel_z */
+	ret = class_create_file(attr_class, &class_attr_accel_z);
+	if (ret) {
+		pr_err("mpu6050: failed to create sysfs class attribute accel_z: %d\n", ret);
+		return ret;
+	}
+	/* Create gyro_x */
+	ret = class_create_file(attr_class, &class_attr_gyro_x);
+	if (ret) {
+		pr_err("mpu6050: failed to create sysfs class attribute gyro_x: %d\n", ret);
+		return ret;
+	}
+	/* Create gyro_y */
+	ret = class_create_file(attr_class, &class_attr_gyro_y);
+	if (ret) {
+		pr_err("mpu6050: failed to create sysfs class attribute gyro_y: %d\n", ret);
+		return ret;
+	}
+	/* Create gyro_z */
+	ret = class_create_file(attr_class, &class_attr_gyro_z);
+	if (ret) {
+		pr_err("mpu6050: failed to create sysfs class attribute gyro_z: %d\n", ret);
+		return ret;
+	}
+	/* Create temperature */
+	ret = class_create_file(attr_class, &class_attr_temperature);
+	if (ret) {
+		pr_err("mpu6050: failed to create sysfs class attribute temperature: %d\n", ret);
+		return ret;
+	}
+
+	pr_info("mpu6050: sysfs class attributes created\n");
+
+	pr_info("mpu6050: module loaded\n");
+	return 0;
+}
+
+static void mpu6050_exit(void)
+{
+	if (attr_class) {
+		class_remove_file(attr_class, &class_attr_accel_x);
+		class_remove_file(attr_class, &class_attr_accel_y);
+		class_remove_file(attr_class, &class_attr_accel_z);
+		class_remove_file(attr_class, &class_attr_gyro_x);
+		class_remove_file(attr_class, &class_attr_gyro_y);
+		class_remove_file(attr_class, &class_attr_gyro_z);
+		class_remove_file(attr_class, &class_attr_temperature);
+		pr_info("mpu6050: sysfs class attributes removed\n");
+
+		class_destroy(attr_class);
+		pr_info("mpu6050: sysfs class destroyed\n");
+	}
+
+	i2c_del_driver(&mpu6050_i2c_driver);
+	pr_info("mpu6050: i2c driver deleted\n");
+
+	pr_info("mpu6050: module exited\n");
+}
+
+module_init(mpu6050_init);
+module_exit(mpu6050_exit);
+
+MODULE_AUTHOR("Andriy.Khulap <[email protected]>");
+MODULE_DESCRIPTION("mpu6050 I2C acc&gyro");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");