Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Lesson 11: Interrupt handling #121

Open
wants to merge 6 commits into
base: Vadym.Mishchuk
Choose a base branch
from
Open

Lesson 11: Interrupt handling #121

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
e8cc971
mpu6050 driver: fix errors, make it compile
vad32m Dec 16, 2018
712d1f5
Interrupts: add code for GPIO interrupt initialization
vad32m Jan 6, 2019
0636f18
Interrupts: move data aquisition to work, create separate workqueue
vad32m Jan 6, 2019
7ccf95d
Interrupts: add filtering for gyroscope and accelerometer data
vad32m Jan 6, 2019
346008f
Interrupts: add sample binding for DTS
vad32m Jan 8, 2019
5fdef10
Interrupts: rework driver, so interrupt and gpio configured in dts
vad32m Jan 9, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
23 changes: 23 additions & 0 deletions mpu6050/dts_binding.txt
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,23 @@
&pio {
mpu6050_pins: mpu6050_pinmux {
pins = "PA6";
function = "irq";
bias-pull-up;
};
};


&i2c0 {
status = "okay";
gl_gyro: gl_gyro@68 {
compatible = "gl,mpu6050";
reg = <0x68>;
status = "okay";

pinctrl-names = "default";
pinctrl-0 = <&mpu6050_pins>;

interrupt-parent = <&pio>;
interrupts = <0 6 2>
};
};
12 changes: 12 additions & 0 deletions mpu6050/mpu6050-regs.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,14 @@
#define _MPU6050_REGS_H

/* Registed addresses */
#define REG_SAMPLERATE_DIV 0x19
#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_INT_STATUS 0x39
#define REG_ACCEL_XOUT_H 0x3B
#define REG_ACCEL_XOUT_L 0x3C
#define REG_ACCEL_YOUT_H 0x3D
Expand All @@ -30,4 +32,14 @@
/* Register values */
#define MPU6050_WHO_AM_I 0x68

#define INT_PIN_CFG_ACTIVE_LOW 0x80
#define INT_PIN_CFG_LATCH_INT_EN 0x20
#define INT_PIN_CFG_STATUS_READ_CLEAR 0x10

#define INT_EN_DATA_RDY 0x01

#define CONF_DLPF_CFG_4 0x04

#define GCON_FCHOICE_DLPF_EN 0x02

#endif /* _MPU6050_REGS_H */
156 changes: 111 additions & 45 deletions mpu6050/mpu6050.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,20 +3,31 @@
#include <linux/device.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/timer.h>
#include <linux/i2c-dev.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>

#include "mpu6050-regs.h"

#define FILT_ORDER 4

struct mpu6050_data {
struct i2c_client *drv_client;
int accel_values_raw[3][FILT_ORDER];
int gyro_values_raw[3][FILT_ORDER];

int raw_store_idx;

int accel_values[3];
int gyro_values[3];
int temperature;
};

static struct mpu6050_data g_mpu6050_data;

static struct workqueue_struct *reader_wq;

static int mpu6050_read_data(void)
{
int temp;
Expand All @@ -25,35 +36,75 @@ static int mpu6050_read_data(void)
if (drv_client == 0)
return -ENODEV;

int store_pos = g_mpu6050_data.raw_store_idx;
/* 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));
g_mpu6050_data.accel_values_raw[0][store_pos]
= (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_ACCEL_XOUT_H));
g_mpu6050_data.accel_values_raw[1][store_pos]
= (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_ACCEL_YOUT_H));
g_mpu6050_data.accel_values_raw[2][store_pos]
= (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));
g_mpu6050_data.gyro_values_raw[0][store_pos]
= (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_GYRO_XOUT_H));
g_mpu6050_data.gyro_values_raw[1][store_pos]
= (s16)((u16)i2c_smbus_read_word_swapped(drv_client, REG_GYRO_YOUT_H));
g_mpu6050_data.gyro_values_raw[2][store_pos]
= (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 void mpu6050_filter_accel_gyro_data(void)
{
int axis;
int i;

for (axis = 0; axis < 3; axis++) {
int sum = 0;
for (i = 0; i < FILT_ORDER; i++)
sum += g_mpu6050_data.accel_values_raw[axis][i];

g_mpu6050_data.accel_values[axis] = sum/FILT_ORDER;
}

for (axis = 0; axis < 3; axis++) {
int sum = 0;
for (i = 0; i < FILT_ORDER; i++)
sum += g_mpu6050_data.gyro_values_raw[axis][i];

g_mpu6050_data.gyro_values[axis] = sum/FILT_ORDER;
}
}

static void mpu_irq_work(struct work_struct *work)
{
mpu6050_read_data();

g_mpu6050_data.raw_store_idx++;
g_mpu6050_data.raw_store_idx = g_mpu6050_data.raw_store_idx % FILT_ORDER;

mpu6050_filter_accel_gyro_data();
}

DECLARE_WORK(read_filter_work, mpu_irq_work);

static irqreturn_t mpu_irq(int irq, void *dev_id)
{
struct i2c_client *drv_client = g_mpu6050_data.drv_client;

if (!queue_work(reader_wq, &read_filter_work)) {
dev_err(&drv_client->dev, "Unable to queue work: already on queue\n");
}

return IRQ_HANDLED;
}

static int mpu6050_probe(struct i2c_client *drv_client,
const struct i2c_device_id *id)
{
Expand All @@ -80,36 +131,60 @@ static int mpu6050_probe(struct i2c_client *drv_client,
"i2c mpu6050 device found, WHO_AM_I register value = 0x%X\n",
ret);

if (drv_client->irq < 0) {
dev_err(&drv_client->dev, "No IRQ specified\n");
return -1;
}

dev_info(&drv_client->dev, "Requesting IRQ: %d\n", drv_client->irq);

if (request_irq(drv_client->irq, mpu_irq, IRQF_TRIGGER_FALLING | IRQF_SHARED, "mpu6050", &drv_client)) {
dev_err(&drv_client->dev, "request IRQ failed\n");
return -1;
}

dev_info(&drv_client->dev, "Registered IRQ: %d\n", drv_client->irq);

g_mpu6050_data.drv_client = drv_client;

/* 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;
i2c_smbus_write_byte_data(drv_client, REG_CONFIG, CONF_DLPF_CFG_4);
i2c_smbus_write_byte_data(drv_client, REG_GYRO_CONFIG, GCON_FCHOICE_DLPF_EN);
i2c_smbus_write_byte_data(drv_client, REG_SAMPLERATE_DIV, 7);

i2c_smbus_write_byte_data(drv_client, REG_INT_PIN_CFG,
INT_PIN_CFG_ACTIVE_LOW |
INT_PIN_CFG_STATUS_READ_CLEAR);
i2c_smbus_write_byte_data(drv_client, REG_INT_ENABLE, INT_EN_DATA_RDY);

dev_info(&drv_client->dev, "i2c driver probed\n");
return 0;
}

static int mpu6050_remove(struct i2c_client *drv_client)
{
free_irq(drv_client->irq, &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 = {
Expand All @@ -125,73 +200,59 @@ static struct i2c_driver mpu6050_i2c_driver = {
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,
static ssize_t temperature_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);
CLASS_ATTR_RO(accel_x);
CLASS_ATTR_RO(accel_y);
CLASS_ATTR_RO(accel_z);
CLASS_ATTR_RO(gyro_x);
CLASS_ATTR_RO(gyro_y);
CLASS_ATTR_RO(gyro_z);
CLASS_ATTR_RO(temperature);

static struct class *attr_class;

Expand Down Expand Up @@ -259,6 +320,8 @@ static int mpu6050_init(void)
return ret;
}

reader_wq = alloc_workqueue("MPU READER", WQ_HIGHPRI, 2);

pr_info("mpu6050: sysfs class attributes created\n");

pr_info("mpu6050: module loaded\n");
Expand All @@ -281,6 +344,9 @@ static void mpu6050_exit(void)
pr_info("mpu6050: sysfs class destroyed\n");
}

cancel_work_sync(&read_filter_work);
destroy_workqueue(reader_wq);

i2c_del_driver(&mpu6050_i2c_driver);
pr_info("mpu6050: i2c driver deleted\n");

Expand Down