Linux驱动开发-①regmap②IIO子系统
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一，regmap
对于spi和i2c,读写寄存器的框架不同，但设备本质一样，因此就有了regmap模型来对其进行简化，提供统一的接口函数来访问寄存器，而且使用很方便，使用时候，调用regmap的读写寄存器函数即可。
整体框架：
struct regmap *regmap;
struct regmap_config regmap_config;
/*对于spi的设备，之前的读写还需要对t->tx_buf,t->rx_buf等进行操作，再t放到message
中，最后再利用spi_sync发送，比较麻烦*/
static unsigned char icm20608c_read_one_reg(struct icm20608c_dev *dev,u8 reg)
{
u8 ret;
unsigned int data;
ret = regmap_read(dev->regmap,reg,&data);//调用regmap的读函数
return (u8)data;
}
void icm20608c_write_one_reg66(struct icm20608c_dev *dev,u8 reg,unsigned char data)
{
regmap_write(dev->regmap,reg,data);//调用regmap的写函数
}
static int icm20608c_probe(struct spi_device *spi)
{
int ret = 0;
icm20608c.regmap_config.reg_bits = 8;//寄存器大小为8bit
icm20608c.regmap_config.val_bits = 8;//寄存器数据值8bit
//icm20608c.regmap_config.read_flag_mask = 0x80;//读掩码
icm20608c.regmap = regmap_init_spi(spi,&icm20608c.regmap_config);//关键就是这个 函 数，将regmap_config和spi设备关联起来，创建出regmap
if(IS_ERR(icm20608c.regmap))
{
return PTR_ERR(icm20608c.regmap);
}
........
}
static int icm20608c_remove(struct spi_device *spi)
{
.........
regmap_exit(icm20608c.regmap)；
return 0;
}
二，IIO子系统
Linux驱动喜欢把程序分层，并且一类的放到一起，IIO子系统就是针对ADC传感器，将比如加速度计，光传感器，气压计，磁力计等等设备，用一样的驱动模型。
结构体iio_dev来表示具体的IIO设备，整体的驱动框架，还是要看设备，比如spi设备，创建的就是spi_driver。主要包含三个内容：①在probe函数中，申请iio_dev内存，进行初始化，注册iio_dev。②iio_chan_spec对通道的建立，比如icm20608设备，有加速度xyz轴,陀螺仪xyz轴和温度，一共七个数据，因此要建立七个通道，在文件中显示，包含：加速度+x或y或z轴+什么数据，比如原始数据，量程等。③iio_info操作函数中，read_raw和write_raw函数具体的实现，具体怎么样实现，还是依靠regmap_read和regmap_write函数，对寄存器进行操作。
2.1初始化相关工作
注意，现在不建立全局变量了，之前会这样写：struct icm20608c_dev icm20608，从而在整个驱动中，直接调用icm20608。比如在remove函数中，想进行注销工作，先indio_dev = spi_get_drvdata(spi);获取indio_dev,再得到dev = iio_priv(indio_dev);，即原来没改过的icm20608地址。
初始化工作中，devm_iio_device_alloc(&spi->dev, sizeof(*dev)) 做了两件事①分配一个struct iio_dev结构的内存，②额外分配sizeof(*dev)大小的内存空间（这里是struct icm20608c_dev的大小。
iio_priv(indio_dev)是一个宏，它返回的是紧跟在iio_dev结构体后面的私有数据区域的指针，dev = iio_priv(indio_dev)获取的是紧跟在iio_dev后面的为驱动私有数据预留的内存区域的指针。
struct icm20608c_dev {
struct spi_device *spi;
struct regmap *regmap;
struct regmap_config regmap_config;
struct mutex lock;
};
/*完成设备号注册 节点注册 spi设备初始化*/
static int icm20608c_probe(struct spi_device *spi)
{
int ret = 0;
struct icm20608c_dev *dev;
struct iio_dev *indio_dev;
/*1.iio_dev申请内存*/
indio_dev = devm_iio_device_alloc(&spi->dev,sizeof(*dev));
if(!indio_dev)
{
return ret;
}
/*2.获取icm20608c_dev结构体地址*/
dev = iio_priv(indio_dev);
dev->spi = spi;
spi_set_drvdata(spi,indio_dev);
mutex_init(&dev->lock);
/*3.初始化iio_dev成员变量*/
indio_dev->dev.parent = &spi->dev;
indio_dev->info = &icm20608c_info;
indio_dev->name = ICMC20608C_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = icm20608_channels;
indio_dev->num_channels = ARRAY_SIZE(icm20608_channels);
/*4.注册iio_dev*/
ret = iio_device_register(indio_dev);
if(ret<0)
{
return ret;
}
/*5.初始化regmap_config并且注册*/
dev->regmap_config.reg_bits = 8;//寄存器大小为8bit
dev->regmap_config.val_bits = 8;//寄存器数据值8bit
//dev.regmap_config.read_flag_mask = 0x80;//读掩码
dev->regmap = regmap_init_spi(spi,&dev->regmap_config);
if(IS_ERR(dev->regmap))
{
goto regmap_error;
return PTR_ERR(dev->regmap);
}
/*6.初始化SPI设备*/
spi->mode = SPI_MODE_0;//时钟模式
spi_setup(spi);
/*7.寄存器初始化内容*/
icm20608c_reg_init(dev);
printk("probe success \r\n");
return 0;
regmap_error:
iio_device_unregister(indio_dev);
return ret;
}
static int icm20608c_remove(struct spi_device *spi)
{
/*这段代码,为了获取icm20608c_dev的地址和iio_dev地址,以便进行解除*/
struct icm20608c_dev *dev;
struct iio_dev *indio_dev;
indio_dev = spi_get_drvdata(spi);
dev = iio_priv(indio_dev);
/*删除regmap,注销iio_dev*/
regmap_exit(dev->regmap);
iio_device_unregister(indio_dev);
printk("remove success \r\n");
return 0;
}
2.2 通道
这个 ICM20608_CHAN(_type, _channel2, _index)宏，就相当于给带入里面的数进行赋值，创建出一个通道结构体，_type是表示各种数据，比如加速度IIO_ACCEL，当modified=1，channel2 为通道修饰符，表示对这个_type还有更具体的描述。 info_mask_shared_by_type 为相同type类型通道共有的（但是名字要一样，比如都是加速度类型，in_accel_sacle），info_mask_separate 为这个通道私有的(比如in_accel_x_raw)，具体在文件中的顺序，依靠scan_index，为0时候，在最前面。
在文件中显示顺序：
#define ICM20608_CHAN(_type, _channel2, _index) \
{ \
.type = _type, \
.modified = 1, \
.channel2 = _channel2, \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_CALIBBIAS), \
.scan_index = _index, \
.scan_type = { \
.sign = 's', \
.realbits = 16, \
.storagebits = 16, \
.shift = 0, \
.endianness = IIO_BE, \
}, \
}
enum inv_icm20608_scan {
INV_ICM20608_SCAN_ACCL_X,
INV_ICM20608_SCAN_ACCL_Y,
INV_ICM20608_SCAN_ACCL_Z,
INV_ICM20608_SCAN_TEMP,
INV_ICM20608_SCAN_GYRO_X,
INV_ICM20608_SCAN_GYRO_Y,
INV_ICM20608_SCAN_GYRO_Z,
INV_ICM20608_SCAN_TIMESTAMP,
};
static const struct iio_chan_spec icm20608_channels[] = {
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW)
|BIT(IIO_CHAN_INFO_OFFSET)
|BIT(IIO_CHAN_INFO_SCALE),
.scan_index = INV_ICM20608_SCAN_TEMP,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.shift = 0,
.endianness = IIO_BE,
},
},
ICM20608_CHAN(IIO_ANGL_VEL,IIO_MOD_X,INV_ICM20608_SCAN_GYRO_X),
ICM20608_CHAN(IIO_ANGL_VEL,IIO_MOD_Y,INV_ICM20608_SCAN_GYRO_Y),
ICM20608_CHAN(IIO_ANGL_VEL,IIO_MOD_Z,INV_ICM20608_SCAN_GYRO_Z),
ICM20608_CHAN(IIO_ACCEL,IIO_MOD_X,INV_ICM20608_SCAN_ACCL_X),
ICM20608_CHAN(IIO_ACCEL,IIO_MOD_Y,INV_ICM20608_SCAN_ACCL_Y),
ICM20608_CHAN(IIO_ACCEL,IIO_MOD_Z,INV_ICM20608_SCAN_ACCL_Z),
};
2.3 读实现
icm20608c_read_raw的返回值，决定读到的数据值，返回值IIO_VAL_INT为1，读到的数据按照整形返回，只有val，没有val2,返回值IIO_VAL_INT_PLUS_MICRO为2，按照val+val2/1000000反馈， 返回值IIO_VAL_INT_PLUS_NANO为2，按照val+val2/1000000000，返回值为负，读取错误。
对于IIO_CHAN_INFO_SCALE量程数据的读取，读到寄存器值为00 01 10 11，要进行转换成实际值，转换关系有数组gyro_scale_icm20608和accel_scale_icm20608构建，最后进行输出。
最终得到的真实数据，比如重力加速度=in_accel_z_raw(读取的值)×in_accel_scale(加速度量程)。
static const int gyro_scale_icm20608[] = {7629, 15258, 30517, 61035};
static const int accel_scale_icm20608[] = {61035, 122070, 244140, 488281};
static unsigned char icm20608c_read_one_reg(struct icm20608c_dev *dev,u8 reg)
{
u8 ret;
unsigned int data;
ret = regmap_read(dev->regmap,reg,&data);
return (u8)data;
}
void icm20608c_write_one_reg66(struct icm20608c_dev *dev,u8 reg,unsigned char data)
{
regmap_write(dev->regmap,reg,data);
}
/*计算出要读寄存器的位置，根据带入的axis计算偏移地址+reg*/
static int icm20608_sensor_show(struct icm20608c_dev *dev, int reg,int axis,int *val)
{
int ind, result;
__be16 d;
ind = (axis - IIO_MOD_X) * 2;
result = regmap_bulk_read(dev->regmap, reg + ind, (u8 *)&d, 2);
if (result)
return -EINVAL;
*val = (short)be16_to_cpup(&d);
return IIO_VAL_INT;
}
static int icm20608c_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
int ret = 0;
unsigned char regdata = 0;
struct icm20608c_dev *dev = iio_priv(indio_dev);
switch(mask){
case IIO_CHAN_INFO_RAW://原始值
mutex_lock(&dev->lock);
switch(chan->type){
case IIO_TEMP:
ret = icm20608_sensor_show(dev, ICM20_TEMP_OUT_H, IIO_MOD_X, val);//IIO_MOD_X意思是就从这个ICM20_TEMP_OUT_H开始
break;
case IIO_ACCEL:
ret = icm20608_sensor_show(dev, ICM20_ACCEL_XOUT_H, chan->channel2, val);
break;
case IIO_ANGL_VEL:
ret = icm20608_sensor_show(dev, ICM20_GYRO_XOUT_H, chan->channel2, val);
break;
default:
ret = -EINVAL;
break;
}
mutex_unlock(&dev->lock);
return ret;
case IIO_CHAN_INFO_CALIBBIAS://校准值
switch(chan->type)
{ //对于加速度和陀螺仪的校准值,首先是校准值寄存器位置不同,其次是分为x,y,z
case IIO_ACCEL:
mutex_lock(&dev->lock);
ret = icm20608_sensor_show(dev, ICM20_XA_OFFSET_H, chan->channel2, val);
mutex_unlock(&dev->lock);
break;
case IIO_ANGL_VEL:
mutex_lock(&dev->lock);
ret = icm20608_sensor_show(dev, ICM20_XG_OFFS_USRH, chan->channel2, val);
mutex_unlock(&dev->lock);
break;
default:
ret = -EINVAL;
break;
}
break;
case IIO_CHAN_INFO_SCALE://度量
switch (chan->type) {
case IIO_ANGL_VEL:
mutex_lock(&dev->lock);
regdata = (icm20608c_read_one_reg(dev, ICM20_GYRO_CONFIG) & 0X18) >> 3;
*val = 0;
*val2 = gyro_scale_icm20608[regdata];
mutex_unlock(&dev->lock);
return IIO_VAL_INT_PLUS_MICRO; /* 值为val+val2/1000000 */
case IIO_ACCEL:
mutex_lock(&dev->lock);
regdata = (icm20608c_read_one_reg(dev, ICM20_ACCEL_CONFIG) & 0X18) >> 3;
*val = 0;
*val2 = accel_scale_icm20608[regdata];;
mutex_unlock(&dev->lock);
return IIO_VAL_INT_PLUS_NANO;/* 值为val+val2/1000000000 */
case IIO_TEMP:
*val = ICM20608_TEMP_SCALE/ 1000000;
*val2 = ICM20608_TEMP_SCALE % 1000000;
return IIO_VAL_INT_PLUS_MICRO; /* 值为val+val2/1000000 */
default:
return -EINVAL;
}
return ret;
case IIO_CHAN_INFO_OFFSET://温度传感器offset值
switch(chan->type)
{
case IIO_TEMP:
*val = ICM20608_TEMP_OFFSET;
break;
default:
ret = -EINVAL;
}
return ret;
default:
break;
}
printk("icm20608c_read_raw\r\n");
return ret;
}
实现：
#include <linux/spi/spi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/device.h>
#include <asm/uaccess.h>
#include <linux/cdev.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/unaligned/be_byteshift.h>
#include "666.h"
#define ICMC20608C_NAME "icm20608c"
#define ICM20608_TEMP_OFFSET 0
#define ICM20608_TEMP_SCALE 326800000
struct icm20608c_dev {
struct spi_device *spi;
struct regmap *regmap;
struct regmap_config regmap_config;
struct mutex lock;
};
static const int gyro_scale_icm20608[] = {7629, 15258, 30517, 61035};
static const int accel_scale_icm20608[] = {61035, 122070, 244140, 488281};
#define ICM20608_CHAN(_type, _channel2, _index) \
{ \
.type = _type, \
.modified = 1, \
.channel2 = _channel2, \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_CALIBBIAS), \
.scan_index = _index, \
.scan_type = { \
.sign = 's', \
.realbits = 16, \
.storagebits = 16, \
.shift = 0, \
.endianness = IIO_BE, \
}, \
}
enum inv_icm20608_scan {
INV_ICM20608_SCAN_ACCL_X,
INV_ICM20608_SCAN_ACCL_Y,
INV_ICM20608_SCAN_ACCL_Z,
INV_ICM20608_SCAN_TEMP,
INV_ICM20608_SCAN_GYRO_X,
INV_ICM20608_SCAN_GYRO_Y,
INV_ICM20608_SCAN_GYRO_Z,
INV_ICM20608_SCAN_TIMESTAMP,
};
static const struct iio_chan_spec icm20608_channels[] = {
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW)
|BIT(IIO_CHAN_INFO_OFFSET)
|BIT(IIO_CHAN_INFO_SCALE),
.scan_index = INV_ICM20608_SCAN_TEMP,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.shift = 0,
.endianness = IIO_BE,
},
},
ICM20608_CHAN(IIO_ANGL_VEL,IIO_MOD_X,INV_ICM20608_SCAN_GYRO_X),
ICM20608_CHAN(IIO_ANGL_VEL,IIO_MOD_Y,INV_ICM20608_SCAN_GYRO_Y),
ICM20608_CHAN(IIO_ANGL_VEL,IIO_MOD_Z,INV_ICM20608_SCAN_GYRO_Z),
ICM20608_CHAN(IIO_ACCEL,IIO_MOD_X,INV_ICM20608_SCAN_ACCL_X),
ICM20608_CHAN(IIO_ACCEL,IIO_MOD_Y,INV_ICM20608_SCAN_ACCL_Y),
ICM20608_CHAN(IIO_ACCEL,IIO_MOD_Z,INV_ICM20608_SCAN_ACCL_Z),
};
static unsigned char icm20608c_read_one_reg(struct icm20608c_dev *dev,u8 reg)
{
u8 ret;
unsigned int data;
ret = regmap_read(dev->regmap,reg,&data);
return (u8)data;
}
void icm20608c_write_one_reg66(struct icm20608c_dev *dev,u8 reg,unsigned char data)
{
regmap_write(dev->regmap,reg,data);
}
static int icm20608_sensor_show(struct icm20608c_dev *dev, int reg,int axis,int *val)
{
int ind, result;
__be16 d;
ind = (axis - IIO_MOD_X) * 2;
result = regmap_bulk_read(dev->regmap, reg + ind, (u8 *)&d, 2);
if (result)
return -EINVAL;
*val = (short)be16_to_cpup(&d);
return IIO_VAL_INT;
}
static int icm20608c_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
int ret = 0;
unsigned char regdata = 0;
struct icm20608c_dev *dev = iio_priv(indio_dev);
switch(mask){
case IIO_CHAN_INFO_RAW://原始值
mutex_lock(&dev->lock);
switch(chan->type){
case IIO_TEMP:
ret = icm20608_sensor_show(dev, ICM20_TEMP_OUT_H, IIO_MOD_X, val);//IIO_MOD_X意思是就从这个ICM20_TEMP_OUT_H开始
break;
case IIO_ACCEL:
ret = icm20608_sensor_show(dev, ICM20_ACCEL_XOUT_H, chan->channel2, val);
break;
case IIO_ANGL_VEL:
ret = icm20608_sensor_show(dev, ICM20_GYRO_XOUT_H, chan->channel2, val);
break;
default:
ret = -EINVAL;
break;
}
mutex_unlock(&dev->lock);
return ret;
case IIO_CHAN_INFO_CALIBBIAS://校准值
switch(chan->type)
{ //对于加速度和陀螺仪的校准值,首先是校准值寄存器位置不同,其次是分为x,y,z
case IIO_ACCEL:
mutex_lock(&dev->lock);
ret = icm20608_sensor_show(dev, ICM20_XA_OFFSET_H, chan->channel2, val);
mutex_unlock(&dev->lock);
break;
case IIO_ANGL_VEL:
mutex_lock(&dev->lock);
ret = icm20608_sensor_show(dev, ICM20_XG_OFFS_USRH, chan->channel2, val);
mutex_unlock(&dev->lock);
break;
default:
ret = -EINVAL;
break;
}
break;
case IIO_CHAN_INFO_SCALE://度量
switch (chan->type) {
case IIO_ANGL_VEL:
mutex_lock(&dev->lock);
regdata = (icm20608c_read_one_reg(dev, ICM20_GYRO_CONFIG) & 0X18) >> 3;
*val = 0;
*val2 = gyro_scale_icm20608[regdata];
mutex_unlock(&dev->lock);
return IIO_VAL_INT_PLUS_MICRO; /* 值为val+val2/1000000 */
case IIO_ACCEL:
mutex_lock(&dev->lock);
regdata = (icm20608c_read_one_reg(dev, ICM20_ACCEL_CONFIG) & 0X18) >> 3;
*val = 0;
*val2 = accel_scale_icm20608[regdata];;
mutex_unlock(&dev->lock);
return IIO_VAL_INT_PLUS_NANO;/* 值为val+val2/1000000000 */
case IIO_TEMP:
*val = ICM20608_TEMP_SCALE/ 1000000;
*val2 = ICM20608_TEMP_SCALE % 1000000;
return IIO_VAL_INT_PLUS_MICRO; /* 值为val+val2/1000000 */
default:
return -EINVAL;
}
return ret;
case IIO_CHAN_INFO_OFFSET://温度传感器offset值
switch(chan->type)
{
case IIO_TEMP:
*val = ICM20608_TEMP_OFFSET;
break;
default:
ret = -EINVAL;
}
return ret;
default:
break;
}
printk("icm20608c_read_raw\r\n");
return ret;
}
static int icm20608c_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
int ret = 0;
printk("icm20608c_write_raw\r\n");
return ret;
}
static int icm20608c_write_raw_get_fmt(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
long mask)
{
int ret = 0;
return ret;
}
/*文件操作函数*/
static struct iio_info icm20608c_info = {
.read_raw = icm20608c_read_raw,
.write_raw = icm20608c_write_raw,
.write_raw_get_fmt = &icm20608c_write_raw_get_fmt,
};
/*寄存器初始化*/
static void icm20608c_reg_init( struct icm20608c_dev *dev)
{
u8 value = 0,ret = 0;
icm20608c_write_one_reg66(dev, ICM20_PWR_MGMT_1,0x80);
mdelay(50);
icm20608c_write_one_reg66(dev, ICM20_PWR_MGMT_1,0x01);
mdelay(50);
ret = icm20608c_read_one_reg(dev, ICM20_PWR_MGMT_1);
printk("ICM20_PWR_MGMT_1 = %X\r\n", ret);
value = icm20608c_read_one_reg(dev, ICM20_WHO_AM_I);
printk("ICM20608 ID = %X\r\n", value);
icm20608c_write_one_reg66(dev, ICM20_SMPLRT_DIV, 0x00);
icm20608c_write_one_reg66(dev, ICM20_GYRO_CONFIG, 0x18);
icm20608c_write_one_reg66(dev, ICM20_ACCEL_CONFIG, 0x18);
icm20608c_write_one_reg66(dev, ICM20_CONFIG, 0x04);
icm20608c_write_one_reg66(dev, ICM20_ACCEL_CONFIG2, 0x04);
icm20608c_write_one_reg66(dev, ICM20_PWR_MGMT_2, 0x00);
icm20608c_write_one_reg66(dev, ICM20_LP_MODE_CFG, 0x00);
icm20608c_write_one_reg66(dev, ICM20_FIFO_EN, 0x00);
};
const struct of_device_id of_icm20608c_table[]={
{.compatible = "wyt,icm20608"},
{}
};
const struct spi_device_id icm20608c_table[]={
{"icm20608c",0},
{ }
};
/*完成设备号注册 节点注册 spi设备初始化*/
static int icm20608c_probe(struct spi_device *spi)
{
int ret = 0;
struct icm20608c_dev *dev;
struct iio_dev *indio_dev;
/*1.iio_dev申请内存*/
indio_dev = devm_iio_device_alloc(&spi->dev,sizeof(*dev));
if(!indio_dev)
{
return ret;
}
/*2.获取icm20608c_dev结构体地址*/
dev = iio_priv(indio_dev);
dev->spi = spi;
spi_set_drvdata(spi,indio_dev);
mutex_init(&dev->lock);
/*3.初始化iio_dev成员变量*/
indio_dev->dev.parent = &spi->dev;
indio_dev->info = &icm20608c_info;
indio_dev->name = ICMC20608C_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = icm20608_channels;
indio_dev->num_channels = ARRAY_SIZE(icm20608_channels);
/*4.注册iio_dev*/
ret = iio_device_register(indio_dev);
if(ret<0)
{
return ret;
}
/*5.初始化regmap_config并且注册*/
dev->regmap_config.reg_bits = 8;//寄存器大小为8bit
dev->regmap_config.val_bits = 8;//寄存器数据值8bit
//dev.regmap_config.read_flag_mask = 0x80;//读掩码
dev->regmap = regmap_init_spi(spi,&dev->regmap_config);
if(IS_ERR(dev->regmap))
{
goto regmap_error;
return PTR_ERR(dev->regmap);
}
/*6.初始化SPI设备*/
spi->mode = SPI_MODE_0;//时钟模式
spi_setup(spi);
/*7.寄存器初始化内容*/
icm20608c_reg_init(dev);
printk("probe success \r\n");
return 0;
regmap_error:
iio_device_unregister(indio_dev);
return ret;
}
static int icm20608c_remove(struct spi_device *spi)
{
/*这段代码,为了获取icm20608c_dev的地址和iio_dev地址,以便进行解除*/
struct icm20608c_dev *dev;
struct iio_dev *indio_dev;
indio_dev = spi_get_drvdata(spi);
dev = iio_priv(indio_dev);
/*删除regmap,注销iio_dev*/
regmap_exit(dev->regmap);
iio_device_unregister(indio_dev);
printk("remove success \r\n");
return 0;
}
static struct spi_driver icm20608c_driver={
.probe = icm20608c_probe,
.remove = icm20608c_remove,
.driver = {
.name = "icm20608c_spi_driver",
.of_match_table = of_icm20608c_table,
},
.id_table = icm20608c_table,
};
static int __init icm20608c_init(void)
{
return spi_register_driver(&icm20608c_driver);
}
static void __exit icm20608c_exit(void)
{
spi_unregister_driver(&icm20608c_driver);
}
/*驱动入口*/
module_init(icm20608c_init);
module_exit(icm20608c_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("WYT");
over
驱动部分总体上都结束了，基本上是字符设备的驱动编写，块设备写一个RAM的，网络设备简单看了看框架，还是要干点项目，后面从100节视频往后，就开始不想学了，后面的章节都是搭建一些环境和软件，也不用动手敲了，这两天把这个会议整完，把操作系统学完。五月开始，找点项目干干，感觉还是没学到什么东西啊！！！！
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