Linux AP3216C驱动
AP3216C是一个近距离环境光传感器linux 驱动通知应用层linux 驱动通知应用层，包含了光强传感器（ALS:AmbientLight Sensor），接近传感器（PS: Proximity Sensor），还有一个红外LED（IR LED）。
1. 介绍
AP3216C是通过IIC进行操作的，操作地址为0x1Elinux操作系统，芯片有多种工作模式使用linux手机，详细的寄存器操作可以阅读芯片手册。我这里利用IIC子系统和IIO子系统进行开发，向应用层提供的sysfs接口。
2. 代码
// SPDX-License-Identifier: GPL-2.0-only
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define AP3216C_REGMAP_NAME "ap3216c_regmap"
#define AP3216C_DRV_NAME "ap3216c"
#define AP3216C_SYSTEMCONG 0x00 /* System Configuration */
#define AP3216C_INTSTATUS 0X01 /* Interrupt Status */
#define AP3216C_INTCLEAR 0X02 /* INT Clear Manner */
#define AP3216C_IRDATALOW 0x0A /* IR Data Low */
#define AP3216C_IRDATAHIGH 0x0B /* IR Data High */
#define AP3216C_ALSDATALOW 0x0C /* ALS Data Low */
#define AP3216C_ALSDATAHIGH 0X0D /* ALS Data High */
#define AP3216C_PSDATALOW 0X0E /* PS Data Low */
#define AP3216C_PSDATAHIGH 0X0F /* PS Data High */
#define AP3216C_ALSCONFIG 0X10 /* ALS Configuration */
#define AP3216C_PSCONFIG 0X20 /* PS Configuration */
#define AP3216C_PSLEDCONFIG 0X21 /* PS LED Driver */
enum ap3216c_idx {
AP3216C_ALS,
AP3216C_PS,
AP3216C_IR,
};
struct ap3216c_data {
struct i2c_client *client;
struct iio_dev *indio_dev;
struct mutex lock;
struct regmap *regmap;
};
static const struct regmap_config ap3216c_regmap_config = {
.name = AP3216C_REGMAP_NAME,
.reg_bits = 8,
.val_bits = 8,
};
static const unsigned long ap3216c_scan_masks[] = {
BIT(AP3216C_ALS) | BIT(AP3216C_PS) | BIT(AP3216C_IR),
0
};
static const struct iio_chan_spec ap3216c_channels[] = {
/* ALS */
{
.type = IIO_INTENSITY,
.modified = 1,
.channel2 = IIO_MOD_LIGHT_BOTH,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
.scan_index = AP3216C_ALS,
.scan_type = {
.sign = 'u',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_LE,
},
},
/* PS */
{
.type = IIO_PROXIMITY,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.scan_index = AP3216C_PS,
.scan_type = {
.sign = 'u',
.realbits = 10,
.storagebits = 16,
.endianness = IIO_LE,
},
},
/* IR */
{
.type = IIO_INTENSITY,
.modified = 1,
.channel2 = IIO_MOD_LIGHT_IR,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.scan_index = AP3216C_IR,
.scan_type = {
.sign = 'u',
.realbits = 10,
.storagebits = 16,
.endianness = IIO_LE,
},
},
};
static int ap3216c_read_als(struct ap3216c_data *data, int *val)
{
unsigned char reg[2];
int ret;
ret = regmap_bulk_read(data->regmap, AP3216C_ALSDATALOW, reg, 2);
if (ret)
return ret;
*val = ((int)reg[1] << 8) | reg[0];
return ret;
}
static int ap3216c_read_ps(struct ap3216c_data *data, int *val)
{
unsigned char reg[2];
int ret;
ret = regmap_bulk_read(data->regmap, AP3216C_PSDATALOW, reg, 2);
if (ret)
return ret;
*val = ((int)(reg[1] & 0X3F) << 4) | (reg[0] & 0X0F);
return ret;
}
static int ap3216c_read_ir(struct ap3216c_data *data, int *val)
{
unsigned char reg[2];
int ret;
ret = regmap_bulk_read(data->regmap, AP3216C_IRDATALOW, reg, 2);
if (ret)
return ret;
*val = ((int)reg[1] << 2) | (reg[0] & 0X03);
return ret;
}
#define AP3216C_SCALE(range) (int)(((long long)range * 1000000) / 65535)
static const int ap3216c_als_scale[] = {AP3216C_SCALE(23360), AP3216C_SCALE(5840),
AP3216C_SCALE(1460), AP3216C_SCALE(365)};
static int ap3216c_read_als_scale(struct ap3216c_data *data, int *val)
{
unsigned int reg;
int ret;
ret = regmap_read(data->regmap, AP3216C_ALSCONFIG, ®);
if (ret)
return ret;
*val = ap3216c_als_scale[((reg & 0X30) >> 4)];
return ret;
}
static int ap3216c_write_als_scale(struct ap3216c_data *data, int val)
{
int i, ret = 0;
for (i=0; i<ARRAY_SIZE(ap3216c_als_scale); ++i)
{
if (ap3216c_als_scale[i] == val)
break;
}
if(i == ARRAY_SIZE(ap3216c_als_scale))
{
ret = -EINVAL;
}
else
{
ret = regmap_write(data->regmap, AP3216C_ALSCONFIG, (unsigned char)(i<<4));
}
return ret;
}
static int ap3216c_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask)
{
struct ap3216c_data *data = iio_priv(indio_dev);
int ret = -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW:
switch (chan->type) {
case IIO_INTENSITY:
switch (chan->channel2) {
case IIO_MOD_LIGHT_BOTH:
mutex_lock(&data->lock);
ret = ap3216c_read_als(data, val);
mutex_unlock(&data->lock);
if (ret)
return ret;
ret = IIO_VAL_INT;
break;
case IIO_MOD_LIGHT_IR:
mutex_lock(&data->lock);
ret = ap3216c_read_ir(data, val);
mutex_unlock(&data->lock);
if (ret)
return ret;
ret = IIO_VAL_INT;
break;
default:
ret = -EINVAL;
break;
}
break;
case IIO_PROXIMITY:
mutex_lock(&data->lock);
ret = ap3216c_read_ps(data, val);
mutex_unlock(&data->lock);
if (ret)
return ret;
ret = IIO_VAL_INT;
break;
default:
ret = -EINVAL;
break;
}
break;
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_INTENSITY:
mutex_lock(&data->lock);
ret = ap3216c_read_als_scale(data, val2);
mutex_unlock(&data->lock);
if (ret)
return ret;
*val = 0;
ret = IIO_VAL_INT_PLUS_MICRO;
break;
default:
ret = -EINVAL;
break;
}
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static const struct iio_info ap3216c_info = {
.read_raw = ap3216c_read_raw,
};
static int ap3216c_init(struct ap3216c_data *data)
{
struct device *dev = &data->client->dev;
int als, ps, ir;
int ret;
ret = regmap_write(data->regmap, AP3216C_SYSTEMCONG, 0x04); // reset ap3216c
if (ret)
return ret;
mdelay(50); // >=10ms
ret = regmap_write(data->regmap, AP3216C_SYSTEMCONG, 0x03); // ALS and PS+IR functions once
if (ret)
return ret;
ret = ap3216c_write_als_scale(data, ap3216c_als_scale[0]); // 23360 lux / Resolution bit
if (ret)
return ret;
ret = regmap_write(data->regmap, AP3216C_PSLEDCONFIG, 0x13); // LED 1 pulse, LED driver ratio 100%
if (ret)
return ret;
ap3216c_read_als(data, &als);
ap3216c_read_ps(data, &ps);
ap3216c_read_ir(data, &ir);
dev_info(dev, "ALS=%d, PS=%d, IR=%dn", als, ps, ir);
return 0;
}
static int ap3216c_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
struct iio_dev *indio_dev;
struct ap3216c_data *data;
int ret;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
indio_dev->name = AP3216C_DRV_NAME;
indio_dev->info = &ap3216c_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = ap3216c_channels;
indio_dev->num_channels = ARRAY_SIZE(ap3216c_channels);
indio_dev->available_scan_masks = ap3216c_scan_masks;
data = iio_priv(indio_dev);
data->indio_dev = indio_dev;
data->client = client;
mutex_init(&data->lock);
i2c_set_clientdata(client, indio_dev);
data->regmap = devm_regmap_init_i2c(client, &ap3216c_regmap_config);
if (IS_ERR(data->regmap)) {
dev_err(&client->dev, "regmap initialization failedn");
return PTR_ERR(data->regmap);
}
ret = ap3216c_init(data);
if (ret)
return ret;
return iio_device_register(indio_dev);
}
static int ap3216c_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
return 0;
}
static const struct of_device_id ap3216c_of_match[] = {
{ .compatible = "lsc,ap3216c" },
{ },
};
MODULE_DEVICE_TABLE(of, ap3216c_of_match);
static struct i2c_device_id ap3216c_id[] = {
{ "ap3216c", 0 },
{ },
};
MODULE_DEVICE_TABLE(i2c, ap3216c_id);
static struct i2c_driver ap3216c_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "ap3216c",
.of_match_table = of_match_ptr(ap3216c_of_match),
},
.probe = ap3216c_probe,
.remove = ap3216c_remove,
.id_table = ap3216c_id,
};
module_i2c_driver(ap3216c_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sonboy");
MODULE_DESCRIPTION("Driver for AP3216C");
3. 设备树
这里示例，只需要i2c设备下添加我们的子设备。
&i2c {
ap3216c@1e {
compatible = "lsc,ap3216c";
reg = <0x1e>;
};
};
4. 运行
加载驱动打印如下信息，驱动加载成功。
进入/sys/bus/iio/devices/iio:device0目录，你的不一定是iio:device0。有如下文件，操作这些文件即可操作设备。
源码获取：
git clone https://github.com/Sonboy97/linux-drivers.git
