linux/drivers/iio/light/cm32181.c
Javier Martinez Canillas 119c4fce68 iio: Export OF module alias information in missing drivers
The I2C core always reports the MODALIAS uevent as "i2c:<client name"
regardless if the driver was matched using the I2C id_table or the
of_match_table. So technically there's no need for a driver to export
the OF table since currently it's not used.

In fact, the I2C device ID table is mandatory for I2C drivers since
a i2c_device_id is passed to the driver's probe function even if the
I2C core used the OF table to match the driver.

And since the I2C core uses different tables, OF-only drivers needs to
have duplicated data that has to be kept in sync and also the dev node
compatible manufacturer prefix is stripped when reporting the MODALIAS.

To avoid the above, the I2C core behavior may be changed in the future
to not require an I2C device table for OF-only drivers and report the
OF module alias. So, it's better to also export the OF table to prevent
breaking module autoloading if that happens.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-08-02 16:36:00 +01:00

372 lines
8.9 KiB
C

/*
* Copyright (C) 2013 Capella Microsystems Inc.
* Author: Kevin Tsai <ktsai@capellamicro.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2, as published
* by the Free Software Foundation.
*/
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/regulator/consumer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/init.h>
/* Registers Address */
#define CM32181_REG_ADDR_CMD 0x00
#define CM32181_REG_ADDR_ALS 0x04
#define CM32181_REG_ADDR_STATUS 0x06
#define CM32181_REG_ADDR_ID 0x07
/* Number of Configurable Registers */
#define CM32181_CONF_REG_NUM 0x01
/* CMD register */
#define CM32181_CMD_ALS_ENABLE 0x00
#define CM32181_CMD_ALS_DISABLE 0x01
#define CM32181_CMD_ALS_INT_EN 0x02
#define CM32181_CMD_ALS_IT_SHIFT 6
#define CM32181_CMD_ALS_IT_MASK (0x0F << CM32181_CMD_ALS_IT_SHIFT)
#define CM32181_CMD_ALS_IT_DEFAULT (0x00 << CM32181_CMD_ALS_IT_SHIFT)
#define CM32181_CMD_ALS_SM_SHIFT 11
#define CM32181_CMD_ALS_SM_MASK (0x03 << CM32181_CMD_ALS_SM_SHIFT)
#define CM32181_CMD_ALS_SM_DEFAULT (0x01 << CM32181_CMD_ALS_SM_SHIFT)
#define CM32181_MLUX_PER_BIT 5 /* ALS_SM=01 IT=800ms */
#define CM32181_MLUX_PER_BIT_BASE_IT 800000 /* Based on IT=800ms */
#define CM32181_CALIBSCALE_DEFAULT 1000
#define CM32181_CALIBSCALE_RESOLUTION 1000
#define MLUX_PER_LUX 1000
static const u8 cm32181_reg[CM32181_CONF_REG_NUM] = {
CM32181_REG_ADDR_CMD,
};
static const int als_it_bits[] = {12, 8, 0, 1, 2, 3};
static const int als_it_value[] = {25000, 50000, 100000, 200000, 400000,
800000};
struct cm32181_chip {
struct i2c_client *client;
struct mutex lock;
u16 conf_regs[CM32181_CONF_REG_NUM];
int calibscale;
};
/**
* cm32181_reg_init() - Initialize CM32181 registers
* @cm32181: pointer of struct cm32181.
*
* Initialize CM32181 ambient light sensor register to default values.
*
* Return: 0 for success; otherwise for error code.
*/
static int cm32181_reg_init(struct cm32181_chip *cm32181)
{
struct i2c_client *client = cm32181->client;
int i;
s32 ret;
ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID);
if (ret < 0)
return ret;
/* check device ID */
if ((ret & 0xFF) != 0x81)
return -ENODEV;
/* Default Values */
cm32181->conf_regs[CM32181_REG_ADDR_CMD] = CM32181_CMD_ALS_ENABLE |
CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT;
cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT;
/* Initialize registers*/
for (i = 0; i < CM32181_CONF_REG_NUM; i++) {
ret = i2c_smbus_write_word_data(client, cm32181_reg[i],
cm32181->conf_regs[i]);
if (ret < 0)
return ret;
}
return 0;
}
/**
* cm32181_read_als_it() - Get sensor integration time (ms)
* @cm32181: pointer of struct cm32181
* @val2: pointer of int to load the als_it value.
*
* Report the current integartion time by millisecond.
*
* Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
*/
static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2)
{
u16 als_it;
int i;
als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD];
als_it &= CM32181_CMD_ALS_IT_MASK;
als_it >>= CM32181_CMD_ALS_IT_SHIFT;
for (i = 0; i < ARRAY_SIZE(als_it_bits); i++) {
if (als_it == als_it_bits[i]) {
*val2 = als_it_value[i];
return IIO_VAL_INT_PLUS_MICRO;
}
}
return -EINVAL;
}
/**
* cm32181_write_als_it() - Write sensor integration time
* @cm32181: pointer of struct cm32181.
* @val: integration time by millisecond.
*
* Convert integration time (ms) to sensor value.
*
* Return: i2c_smbus_write_word_data command return value.
*/
static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val)
{
struct i2c_client *client = cm32181->client;
u16 als_it;
int ret, i, n;
n = ARRAY_SIZE(als_it_value);
for (i = 0; i < n; i++)
if (val <= als_it_value[i])
break;
if (i >= n)
i = n - 1;
als_it = als_it_bits[i];
als_it <<= CM32181_CMD_ALS_IT_SHIFT;
mutex_lock(&cm32181->lock);
cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=
~CM32181_CMD_ALS_IT_MASK;
cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=
als_it;
ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
mutex_unlock(&cm32181->lock);
return ret;
}
/**
* cm32181_get_lux() - report current lux value
* @cm32181: pointer of struct cm32181.
*
* Convert sensor raw data to lux. It depends on integration
* time and calibscale variable.
*
* Return: Positive value is lux, otherwise is error code.
*/
static int cm32181_get_lux(struct cm32181_chip *cm32181)
{
struct i2c_client *client = cm32181->client;
int ret;
int als_it;
unsigned long lux;
ret = cm32181_read_als_it(cm32181, &als_it);
if (ret < 0)
return -EINVAL;
lux = CM32181_MLUX_PER_BIT;
lux *= CM32181_MLUX_PER_BIT_BASE_IT;
lux /= als_it;
ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
if (ret < 0)
return ret;
lux *= ret;
lux *= cm32181->calibscale;
lux /= CM32181_CALIBSCALE_RESOLUTION;
lux /= MLUX_PER_LUX;
if (lux > 0xFFFF)
lux = 0xFFFF;
return lux;
}
static int cm32181_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct cm32181_chip *cm32181 = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_PROCESSED:
ret = cm32181_get_lux(cm32181);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_CALIBSCALE:
*val = cm32181->calibscale;
return IIO_VAL_INT;
case IIO_CHAN_INFO_INT_TIME:
*val = 0;
ret = cm32181_read_als_it(cm32181, val2);
return ret;
}
return -EINVAL;
}
static int cm32181_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct cm32181_chip *cm32181 = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_CALIBSCALE:
cm32181->calibscale = val;
return val;
case IIO_CHAN_INFO_INT_TIME:
ret = cm32181_write_als_it(cm32181, val2);
return ret;
}
return -EINVAL;
}
/**
* cm32181_get_it_available() - Get available ALS IT value
* @dev: pointer of struct device.
* @attr: pointer of struct device_attribute.
* @buf: pointer of return string buffer.
*
* Display the available integration time values by millisecond.
*
* Return: string length.
*/
static ssize_t cm32181_get_it_available(struct device *dev,
struct device_attribute *attr, char *buf)
{
int i, n, len;
n = ARRAY_SIZE(als_it_value);
for (i = 0, len = 0; i < n; i++)
len += sprintf(buf + len, "0.%06u ", als_it_value[i]);
return len + sprintf(buf + len, "\n");
}
static const struct iio_chan_spec cm32181_channels[] = {
{
.type = IIO_LIGHT,
.info_mask_separate =
BIT(IIO_CHAN_INFO_PROCESSED) |
BIT(IIO_CHAN_INFO_CALIBSCALE) |
BIT(IIO_CHAN_INFO_INT_TIME),
}
};
static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
S_IRUGO, cm32181_get_it_available, NULL, 0);
static struct attribute *cm32181_attributes[] = {
&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
NULL,
};
static const struct attribute_group cm32181_attribute_group = {
.attrs = cm32181_attributes
};
static const struct iio_info cm32181_info = {
.driver_module = THIS_MODULE,
.read_raw = &cm32181_read_raw,
.write_raw = &cm32181_write_raw,
.attrs = &cm32181_attribute_group,
};
static int cm32181_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct cm32181_chip *cm32181;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*cm32181));
if (!indio_dev) {
dev_err(&client->dev, "devm_iio_device_alloc failed\n");
return -ENOMEM;
}
cm32181 = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
cm32181->client = client;
mutex_init(&cm32181->lock);
indio_dev->dev.parent = &client->dev;
indio_dev->channels = cm32181_channels;
indio_dev->num_channels = ARRAY_SIZE(cm32181_channels);
indio_dev->info = &cm32181_info;
indio_dev->name = id->name;
indio_dev->modes = INDIO_DIRECT_MODE;
ret = cm32181_reg_init(cm32181);
if (ret) {
dev_err(&client->dev,
"%s: register init failed\n",
__func__);
return ret;
}
ret = devm_iio_device_register(&client->dev, indio_dev);
if (ret) {
dev_err(&client->dev,
"%s: regist device failed\n",
__func__);
return ret;
}
return 0;
}
static const struct i2c_device_id cm32181_id[] = {
{ "cm32181", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, cm32181_id);
static const struct of_device_id cm32181_of_match[] = {
{ .compatible = "capella,cm32181" },
{ }
};
MODULE_DEVICE_TABLE(of, cm32181_of_match);
static struct i2c_driver cm32181_driver = {
.driver = {
.name = "cm32181",
.of_match_table = of_match_ptr(cm32181_of_match),
},
.id_table = cm32181_id,
.probe = cm32181_probe,
};
module_i2c_driver(cm32181_driver);
MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
MODULE_DESCRIPTION("CM32181 ambient light sensor driver");
MODULE_LICENSE("GPL");