一，前言
MPU6500六轴陀螺仪linux驱动(spi)--Apple的学习笔记昨天已经做了spi的linux驱动，它和i2c的驱动有很多雷同，所以我也参考linux的设计思路，雷同部分合并为core。测试通过。工程上传到我的gitee工程17。
二，驱动源码
apple6500.h
/**********************************************************************************
Copyright (C), by AppleCai
Project : Study Kernel
Description : BSP level for MPU6500
CPU and Compiler : AM335x,ARM-LINIX-GCC
|----------------------------------------------------------------------------------
| R E V I S I O N H I S T O R Y
|----------------------------------------------------------------------------------
| Date Version Author Description
| -------- ------- ------ ---------------------------------------------------
| 2020-12-14 1.0.0 AppleCai MPU6500_001: Initial release version
**********************************************************************************/
#ifndef _APPLE6500_H_
#define _APPLE6500_H_
#define APPLE6500_DRV_NAME "apple6500sensor"
struct apple6500;
struct device;
struct apple6500_transfer_func {
int (*read) (struct device *dev, unsigned off);
int (*write) (struct device *dev, unsigned off, unsigned char v);
int (*readblock)(struct device *dev, unsigned off,unsigned char *buf, size_t size);
};
int apple6500_remove(struct apple6500 *m);
struct apple6500 *apple6500_probe(struct device *dev,const struct apple6500_transfer_func *trops);
#endif
apple6500_core.c
/**********************************************************************************
Copyright (C), by AppleCai
Project : Study Kernel
Description : BSP level for MPU6500
CPU and Compiler : AM335x,ARM-LINIX-GCC
|----------------------------------------------------------------------------------
| R E V I S I O N H I S T O R Y
|----------------------------------------------------------------------------------
| Date Version Author Description
| -------- ------- ------ ---------------------------------------------------
| 2020-12-08 1.0.0 AppleCai MPU6500_001: Initial release version just add frame
| 2020-12-09 1.0.1 AppleCai MPU6500_002: add WMI reg and I2C DTB
| 2020-12-10 1.0.2 AppleCai MPU6500_003: add Initial reg and report functions
| 2020-12-11 1.0.3 AppleCai MPU6500_004: Optimize code structure
| 2020-12-12 1.0.4 AppleCai MPU6500_005: change i2c to spi
| 2020-12-13 1.0.5 AppleCai MPU6500_006: fix bug:spi send cmd then read incorrect
| 2020-12-14 1.0.6 AppleCai MPU6500_007: merge i2c and spi to core
**********************************************************************************/
#include
#include
#include
#include
#include
#include
#include "apple6500.h"
#define POLL_INTERVAL 200
#define POLL_INTERVAL_MAX 500
struct apple6500_chip_reg {
/* regs */
char who_am_i;
char pwr_mgmt_1;
char pwr_mgmt_2;
char smplrt_div;
char sensor_config;
char accel_config;
char accel_config2;
char accel_xout_h;
char temp_out_h;
char gyro_xout_h;
char gyro_config;
char signal_path_reset;
char user_config;
};
static const struct apple6500_chip_reg chipregs={
/* reg addr */
.who_am_i= 117,
.pwr_mgmt_1= 107,
.pwr_mgmt_2= 108,
.smplrt_div= 25,
.sensor_config= 26,
.gyro_config= 27,
.accel_config= 28,
.accel_config2= 29,
.accel_xout_h= 59,
.temp_out_h= 65,
.gyro_xout_h= 67,
.signal_path_reset= 104,
.user_config= 106,
};
struct apple6500_chip_config{
char chip_id;
char chip_enable_sensor;
char chip_frequency_acc;
char chip_frequency_gyro;
char chip_frequency_DIV;
char chip_reset;
char chip_sensor_reset;
char chip_sensitivity_acc;
char chip_sensitivity_gyro;
char chip_selectedclock;
char chip_usrconfig;
};
/* apple6500 status */
struct apple6500 {
struct device *dev;
struct input_polled_dev *idev;
const struct apple6500_chip_reg *regs;
struct apple6500_chip_config cfgs;
const struct apple6500_transfer_func *tf;
struct mutex mulock;
int bustype;
};
static void apple6500_poll(struct input_polled_dev *dev)
{
struct apple6500 *m = dev->private;
int ax, ay, az,gx,gy,gz,temp;
int ret;
u8 buf[14];
mutex_lock(&m->mulock);
ret = m->tf->readblock(m->dev, m->regs->accel_xout_h, buf, sizeof(buf));
if (ret < 0)
{
dev_err(m->dev, "polling error\n");
return;
}
mutex_unlock(&m->mulock);
ax = ( buf[0] << 8 ) | buf[1];
ay = ( buf[2] << 8 ) | buf[3];
az = ( buf[4] << 8 ) | buf[5];
temp = ( buf[6] << 8 ) | buf[7];
gx = ( buf[8] << 8 ) | buf[9];
gy = ( buf[10] << 8 ) | buf[11];
gz = ( buf[12] << 8 ) | buf[13];
input_report_abs(dev->input, ABS_X, ax);
input_report_abs(dev->input, ABS_Y, ay);
input_report_abs(dev->input, ABS_Z, az);
input_report_abs(dev->input, ABS_RX, gx);
input_report_abs(dev->input, ABS_RY, gy);
input_report_abs(dev->input, ABS_RZ, gz);
input_report_abs(dev->input, ABS_MISC, temp);//Temperature = 36.53 + regval/340
input_sync(dev->input);
}
static void apple6500_Init_reg(struct apple6500_chip_config * cfgs)
{
cfgs->chip_id = 0x70; // id for MPU6500
cfgs->chip_enable_sensor = 0; // enable all
cfgs->chip_frequency_acc = 4; // 50Hz/2=25Hz then select 20Hz
cfgs->chip_frequency_DIV = 19; // 1000/(19+1) = 50Hz clock for acc
cfgs->chip_frequency_gyro = 4; // 1K 20Hz,due to FCHOICE_B=0
cfgs->chip_reset = 1<<7; // true
cfgs->chip_sensor_reset = 7; // all reset
cfgs->chip_usrconfig = 0x11; // spi enable and reset all path
cfgs->chip_sensitivity_acc = 0; // 65536/4 = 16384 LBS/s
cfgs->chip_sensitivity_gyro = 3<<3; // 65536/4000 = 16.384 LBS/s
cfgs->chip_selectedclock = 1; // PLL with axis
}
static int apple6500_CheckId(struct apple6500 *m)
{
int IdNum = 0;
IdNum = m->tf->read(m->dev, m->regs->who_am_i);
if(m->cfgs.chip_id != IdNum)
{
dev_err(m->dev, "Not found MPU6500,id is %d\n",IdNum);
return -ENXIO;
}
return 0;
}
static int apple6500_ResetChipAndSelectClock(struct apple6500 *m)
{
int err = 0;
int val = 0;
val = m->cfgs.chip_reset+m->cfgs.chip_selectedclock;
err = m->tf->write(m->dev, m->regs->pwr_mgmt_1,val);
if(err)
{
dev_err(m->dev, "reset command error\n");
}
/* if use spi shall add delay timer */
if(m->bustype == BUS_SPI)
{
msleep(100);
err = m->tf->write(m->dev, m->regs->signal_path_reset,m->cfgs.chip_sensor_reset);
if(err)
{
dev_err(m->dev, "reset command2 error\n");
}
msleep(100);
err = m->tf->write(m->dev, m->regs->user_config,m->cfgs.chip_usrconfig);
if(err)
{
dev_err(m->dev, "usr config error\n");
}
msleep(100);
}
return err;
}
static int apple6500_EnableSensor(struct apple6500 *m)
{
int err = 0;
err = m->tf->write(m->dev, m->regs->pwr_mgmt_2,m->cfgs.chip_enable_sensor);
if(err)
{
dev_err(m->dev, "enable command error\n");
}
return err;
}
static int apple6500_SetACCSamplerate(struct apple6500 *m)
{
int err = 0;
err = m->tf->write(m->dev, m->regs->accel_config2,m->cfgs.chip_frequency_acc);
if(err)
{
dev_err(m->dev, "set acc bandwidths error\n");
}
err = m->tf->write(m->dev, m->regs->smplrt_div,m->cfgs.chip_frequency_DIV);
if(err)
{
dev_err(m->dev, "set acc clock division error\n");
}
return err;
}
static int apple6500_SetGyroSamplerate(struct apple6500 *m)
{
int err = 0;
err = m->tf->write(m->dev, m->regs->sensor_config,m->cfgs.chip_frequency_gyro);
if(err)
{
dev_err(m->dev, "set gyro bandwidths error\n");
}
return err;
}
static int apple6500_SetAccSensitivity(struct apple6500 *m)
{
int err = 0;
err = m->tf->write(m->dev, m->regs->accel_config,m->cfgs.chip_sensitivity_acc);
if(err)
{
dev_err(m->dev, "set acc sensitivity error\n");
}
return err;
}
static int apple6500_SetGyroSensitivity(struct apple6500 *m)
{
int err = 0;
err = m->tf->write(m->dev, m->regs->gyro_config,m->cfgs.chip_sensitivity_gyro);
if(err)
{
dev_err(m->dev, "set gyro sensitivity error\n");
}
return err;
}
static int apple6500_Init(struct apple6500 *m)
{
int ret = 0;
/* load default configuration value */
apple6500_Init_reg(&m->cfgs);
/* check id */
ret = apple6500_CheckId(m);
if (ret < 0)
return -1;
/* set reset chip and select clock */
ret = apple6500_ResetChipAndSelectClock(m);
/* enable acc and gyro */
ret = apple6500_EnableSensor(m);
/* set sample rate and bandwith for acc*/
ret = apple6500_SetACCSamplerate(m);
/* set sample rate and bandwith for gyro*/
ret = apple6500_SetGyroSamplerate(m);
/* set sensitivity for acc*/
ret = apple6500_SetAccSensitivity(m);
/* set sensitivity for gyro*/
ret = apple6500_SetGyroSensitivity(m);
if (ret < 0)
{
dev_err(m->dev,"init error\n");
return -1;
}
return ret;
}
/* Initialize the APPLE6500 chip */
static void apple6500_open(struct input_polled_dev *dev)
{
int ret = 0;
struct apple6500 *m = dev->private;
mutex_init(&m->mulock);
mutex_lock(&m->mulock);
ret = apple6500_Init(m);
mutex_unlock(&m->mulock);
if (ret < 0)
{
dev_err(m->dev, "apple6500 initialization failed\n");
return;
}
}
static void apple6500_close(struct input_polled_dev *dev)
{
struct apple6500 *m = dev->private;
}
/*
* probe
*/
struct apple6500 *apple6500_probe(struct device *dev,const struct apple6500_transfer_func *trops)
{
struct input_polled_dev *idev;
struct apple6500 *m;
int err;
m = devm_kzalloc(dev, sizeof(*m), GFP_KERNEL);
if (!m)
return -ENOMEM;
idev = devm_input_allocate_polled_device(dev);
if (!idev)
return -ENOMEM;
m->dev = dev;
m->idev = idev;
m->regs = &chipregs;
m->tf = trops;
idev->private = m;
idev->input->name = APPLE6500_DRV_NAME;
idev->input->id.bustype = m->bustype;
idev->input->id.vendor = 0xABCD;
idev->input->id.product = 0x0001;
idev->input->id.version = 0x0100;
idev->poll = apple6500_poll;
idev->poll_interval = POLL_INTERVAL;
idev->poll_interval_max = POLL_INTERVAL_MAX;
idev->open = apple6500_open;
idev->close = apple6500_close;
__set_bit(EV_ABS, idev->input->evbit);
input_set_abs_params(idev->input, ABS_X, -32768, 32767, 0, 0);
input_set_abs_params(idev->input, ABS_Y, -32768, 32767, 0, 0);
input_set_abs_params(idev->input, ABS_Z, -32768, 32767, 0, 0);
input_set_abs_params(idev->input, ABS_RX, -32768, 32767, 0, 0);
input_set_abs_params(idev->input, ABS_RY, -32768, 32767, 0, 0);
input_set_abs_params(idev->input, ABS_RZ, -32768, 32767, 0, 0);
input_set_abs_params(idev->input, ABS_MISC, -32768, 32767, 0, 0);
err = input_register_polled_device(idev);
if (err) {
input_unregister_polled_device(idev);
dev_err(dev, "failed to register polled input device\n");
goto out;
}
return m;
out:
input_unregister_polled_device(idev);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(apple6500_probe);
int apple6500_remove(struct apple6500 *m)
{
//disable sensor
input_unregister_polled_device(m->idev);
input_free_polled_device(m->idev);
dev_info(m->dev, "%s: removed\n", APPLE6500_DRV_NAME);
kfree(m);
return 0;
}
EXPORT_SYMBOL_GPL(apple6500_remove);
MODULE_AUTHOR("AppleCai");
MODULE_DESCRIPTION("APPLE6500 Acceler and Gyro Driver");
MODULE_LICENSE("GPL");
apple6500_i2c.c
/**********************************************************************************
Copyright (C), by AppleCai
Project : Study Kernel
Description : BSP level for MPU6500
CPU and Compiler : AM335x,ARM-LINIX-GCC
|----------------------------------------------------------------------------------
| R E V I S I O N H I S T O R Y
|----------------------------------------------------------------------------------
| Date Version Author Description
| -------- ------- ------ ---------------------------------------------------
| 2020-12-14 1.0.0 AppleCai MPU6500_001: Initial release version
**********************************************************************************/
#include
#include
#include
#include
#include
#include
#include
#include "apple6500.h"
#if 0 //dts
&i2c2 {
pinctrl-names = "default";
pinctrl-0 = <&i2c2_pins>;
status = "okay";
clock-frequency = <100000>;
apple_MPU6500: apple_MPU6500@68 {
compatible ="applecai,apple6500i2c";
reg = <0x68>;
};
};
#endif
static int apple6500_read_i2c(struct device *dev, unsigned off)
{
struct i2c_client *c = to_i2c_client(dev);
int ret;
ret = i2c_smbus_read_byte_data(c, off);
if (ret < 0)
dev_err(dev,"failed to read register 0x%02x, error %d\n",off, ret);
return ret;
}
static int apple6500_write_i2c(struct device *dev, unsigned off, unsigned char v)
{
struct i2c_client *c = to_i2c_client(dev);
int error;
error = i2c_smbus_write_byte_data(c, off, v);
if (error < 0) {
dev_err(dev,"failed to write to register 0x%02x, error %d\n",off, error);
return error;
}
return 0;
}
static int apple6500_read_block_i2c(struct device *dev, unsigned off,unsigned char *buf, size_t size)
{
struct i2c_client *c = to_i2c_client(dev);
int err;
err = i2c_smbus_read_i2c_block_data(c, off, size, buf);
if (err < 0) {
dev_err(&c->dev,"failed to read block data error %d\n", err);
return err;
}
return 0;
}
static const struct apple6500_transfer_func apple6500_tf_i2c = {
.write = apple6500_write_i2c,
.read = apple6500_read_i2c,
.readblock = apple6500_read_block_i2c
};
static const struct of_device_id apple6500_dt_ids[] = {
{ .compatible = "applecai,apple6500i2c"},
{ /* sentinel */ }
};
/*
* I2C probe
*/
static int apple6500_i2c_probe(struct i2c_client *c,
const struct i2c_device_id *id)
{
struct apple6500 *m;
int err;
/* Check basic functionality */
err = i2c_check_functionality(c->adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA|
I2C_FUNC_SMBUS_READ_BYTE_DATA|
I2C_FUNC_SMBUS_READ_I2C_BLOCK);
if (!err) {
dev_err(&c->dev, "%s adapter not supported\n",
dev_driver_string(&c->adapter->dev));
return -ENODEV;
}
m = apple6500_probe(&c->dev,&apple6500_tf_i2c);
if (IS_ERR(m))
return PTR_ERR(m);
i2c_set_clientdata(c, m);
return 0;
}
static int apple6500_i2c_remove(struct i2c_client *c)
{
struct apple6500 *m = i2c_get_clientdata(c);
return apple6500_remove(m);
}
MODULE_DEVICE_TABLE(of, apple6500_dt_ids);
static struct i2c_driver apple6500_driver = {
.driver = {
.name = APPLE6500_DRV_NAME,
.of_match_table = apple6500_dt_ids,
},
.probe = apple6500_i2c_probe,
.remove = apple6500_i2c_remove,
};
module_i2c_driver(apple6500_driver);
MODULE_AUTHOR("AppleCai");
MODULE_DESCRIPTION("APPLE6500 Acceler and Gyro Driver I2C");
MODULE_LICENSE("GPL");
apple6500_spi.c
/**********************************************************************************
Copyright (C), by AppleCai
Project : Study Kernel
Description : BSP level for MPU6500
CPU and Compiler : AM335x,ARM-LINIX-GCC
|----------------------------------------------------------------------------------
| R E V I S I O N H I S T O R Y
|----------------------------------------------------------------------------------
| Date Version Author Description
| -------- ------- ------ ---------------------------------------------------
| 2020-12-14 1.0.0 AppleCai MPU6500_001: Initial release version
**********************************************************************************/
#if 0 // DTS
spi0_pins: pinmux_spi0_pins {
pinctrl-single,pins = <
AM33XX_PADCONF(AM335X_PIN_SPI0_SCLK,PIN_INPUT, MUX_MODE0) /* SPI0_SCLK */
AM33XX_PADCONF(AM335X_PIN_SPI0_D0, PIN_INPUT_PULLUP, MUX_MODE0) /* SPI0_D0 */
AM33XX_PADCONF(AM335X_PIN_SPI0_D1, PIN_OUTPUT, MUX_MODE0) /* SPI0_D1 */
AM33XX_PADCONF(AM335X_PIN_SPI0_CS0, PIN_OUTPUT, MUX_MODE0) /* SPI0_CS0 */
>;
};
&spi0 {
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&spi0_pins>;
apple_MPU6500spi@0 {
compatible ="applecai,apple6500spi";//"rohm,dh2228fv";
reg = <0>;
spi-cpol;
spi-cpha;
spi-max-frequency = <100000>;
spi-tx-bus-width=<1>;
spi-rx-bus-width=<1>;
};
};
#endif
#include
#include
#include
#include
#include
#include
#include
#include "apple6500.h"
/* spi */
#define APPLE6500_CMD_MULTB (1 << 6)
#define APPLE6500_CMD_READ (1 << 7)
#define APPLE6500_WRITECMD(reg) (reg & 0x7F)
#define APPLE6500_READCMD(reg) (APPLE6500_CMD_READ | (reg & 0x7F))
static int apple6500_read_spi(struct device *dev, unsigned off)
{
struct spi_device *spi = to_spi_device(dev);
unsigned char cmd;
int ret;
cmd = APPLE6500_READCMD(off);
ret=spi_w8r8(spi, cmd);
return ret;
}
static int apple6500_write_spi(struct device *dev, unsigned off, unsigned char v)
{
struct spi_device *spi = to_spi_device(dev);
unsigned char buf[2];
buf[0] = APPLE6500_WRITECMD(off);
buf[1] = v;
return spi_write(spi, buf, sizeof(buf));
}
static int apple6500_read_block_spi(struct device *dev, unsigned off,unsigned char *buf, size_t size)
{
struct spi_device *spi = to_spi_device(dev);
ssize_t status;
off = APPLE6500_READCMD(off);
status = spi_write_then_read(spi, &off, 1, buf, size);
return (status < 0) ? status : 0;
}
static const struct apple6500_transfer_func apple6500_tf_spi = {
.write = apple6500_write_spi,
.read = apple6500_read_spi,
.readblock = apple6500_read_block_spi,
};
static const struct of_device_id apple6500spi_dt_ids[] = {
{ .compatible = "applecai,apple6500spi"},
{ /* sentinel */ }
};
/*
* I2C init/probing/exit functions
*/
static int apple6500_spi_probe(struct spi_device *spi)
{
struct apple6500 *m;
m = apple6500_probe(&spi->dev,&apple6500_tf_spi);
if (IS_ERR(m))
return PTR_ERR(m);
spi_set_drvdata(spi, m);
return 0;
}
static int apple6500_spi_remove(struct spi_device *spi)
{
struct apple6500 *m = spi_get_drvdata(spi);
return apple6500_remove(m);
}
MODULE_DEVICE_TABLE(of, apple6500spi_dt_ids);
static struct spi_driver apple6500_driver = {
.driver = {
.name = APPLE6500_DRV_NAME,
.of_match_table = apple6500spi_dt_ids,
},
.probe = apple6500_spi_probe,
.remove = apple6500_spi_remove,
};
module_spi_driver(apple6500_driver);
MODULE_AUTHOR("AppleCai");
MODULE_DESCRIPTION("APPLE6500 Acceler and Gyro Driver SPI");
MODULE_LICENSE("GPL");
Makefile
#copyright by AppleCai
KERNELDIR :=/home/applecai/studybr/buildroot-2020.05.2/output/build/linux-custom
CURRENT_PATH := $(shell pwd)
obj-m += apple6500_core.o
obj-m += apple6500_i2c.o
obj-m += apple6500_spi.o
build: kernel_modules
kernel_modules:
$(MAKE) -C $(KERNELDIR) M=$(CURRENT_PATH) modules
clean:
$(MAKE) -C $(KERNELDIR) M=$(CURRENT_PATH) clean