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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2013 Capella Microsystems Inc.
* Author: Kevin Tsai <ktsai@capellamicro.com>
*/
#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/mod_devicetable.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_WH 0x01
#define CM32181_REG_ADDR_WL 0x02
#define CM32181_REG_ADDR_TEST 0x03
#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 4
/* CMD register */
#define CM32181_CMD_ALS_DISABLE BIT(0)
#define CM32181_CMD_ALS_INT_EN BIT(1)
#define CM32181_CMD_ALS_THRES_WINDOW BIT(2)
#define CM32181_CMD_ALS_PERS_SHIFT 4
#define CM32181_CMD_ALS_PERS_MASK (0x03 << CM32181_CMD_ALS_PERS_SHIFT)
#define CM32181_CMD_ALS_PERS_DEFAULT (0x01 << CM32181_CMD_ALS_PERS_SHIFT)
#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_LUX_PER_BIT 500 /* ALS_SM=01 IT=800ms */
#define CM32181_LUX_PER_BIT_RESOLUTION 100000
#define CM32181_LUX_PER_BIT_BASE_IT 800000 /* Based on IT=800ms */
#define CM32181_CALIBSCALE_DEFAULT 100000
#define CM32181_CALIBSCALE_RESOLUTION 100000
#define SMBUS_ALERT_RESPONSE_ADDRESS 0x0c
/* CPM0 Index 0: device-id (3218 or 32181), 1: Unknown, 2: init_regs_bitmap */
#define CPM0_REGS_BITMAP 2
#define CPM0_HEADER_SIZE 3
/* CPM1 Index 0: lux_per_bit, 1: calibscale, 2: resolution (100000) */
#define CPM1_LUX_PER_BIT 0
#define CPM1_CALIBSCALE 1
#define CPM1_SIZE 3
/* CM3218 Family */
static const int cm3218_als_it_bits[] = { 0, 1, 2, 3 };
static const int cm3218_als_it_values[] = { 100000, 200000, 400000, 800000 };
/* CM32181 Family */
static const int cm32181_als_it_bits[] = { 12, 8, 0, 1, 2, 3 };
static const int cm32181_als_it_values[] = {
25000, 50000, 100000, 200000, 400000, 800000
};
struct cm32181_chip {
struct i2c_client *client;
struct device *dev;
struct mutex lock;
u16 conf_regs[CM32181_CONF_REG_NUM];
unsigned long init_regs_bitmap;
int calibscale;
int lux_per_bit;
int lux_per_bit_base_it;
int num_als_it;
const int *als_it_bits;
const int *als_it_values;
};
static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2);
#ifdef CONFIG_ACPI
/**
* cm32181_acpi_get_cpm() - Get CPM object from ACPI
* @dev: pointer of struct device.
* @obj_name: pointer of ACPI object name.
* @values: pointer of array for return elements.
* @count: maximum size of return array.
*
* Convert ACPI CPM table to array.
*
* Return: -ENODEV for fail. Otherwise is number of elements.
*/
static int cm32181_acpi_get_cpm(struct device *dev, char *obj_name,
u64 *values, int count)
{
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *cpm, *elem;
acpi_handle handle;
acpi_status status;
int i;
handle = ACPI_HANDLE(dev);
if (!handle)
return -ENODEV;
status = acpi_evaluate_object(handle, obj_name, NULL, &buffer);
if (ACPI_FAILURE(status)) {
dev_err(dev, "object %s not found\n", obj_name);
return -ENODEV;
}
cpm = buffer.pointer;
if (cpm->package.count > count)
dev_warn(dev, "%s table contains %u values, only using first %d values\n",
obj_name, cpm->package.count, count);
count = min_t(int, cpm->package.count, count);
for (i = 0; i < count; i++) {
elem = &(cpm->package.elements[i]);
values[i] = elem->integer.value;
}
kfree(buffer.pointer);
return count;
}
static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)
{
u64 vals[CPM0_HEADER_SIZE + CM32181_CONF_REG_NUM];
struct device *dev = cm32181->dev;
int i, count;
count = cm32181_acpi_get_cpm(dev, "CPM0", vals, ARRAY_SIZE(vals));
if (count <= CPM0_HEADER_SIZE)
return;
count -= CPM0_HEADER_SIZE;
cm32181->init_regs_bitmap = vals[CPM0_REGS_BITMAP];
cm32181->init_regs_bitmap &= GENMASK(count - 1, 0);
for_each_set_bit(i, &cm32181->init_regs_bitmap, count)
cm32181->conf_regs[i] = vals[CPM0_HEADER_SIZE + i];
count = cm32181_acpi_get_cpm(dev, "CPM1", vals, ARRAY_SIZE(vals));
if (count != CPM1_SIZE)
return;
cm32181->lux_per_bit = vals[CPM1_LUX_PER_BIT];
/* Check for uncalibrated devices */
if (vals[CPM1_CALIBSCALE] == CM32181_CALIBSCALE_DEFAULT)
return;
cm32181->calibscale = vals[CPM1_CALIBSCALE];
/* CPM1 lux_per_bit is for the current it value */
cm32181_read_als_it(cm32181, &cm32181->lux_per_bit_base_it);
}
#else
static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)
{
}
#endif /* CONFIG_ACPI */
/**
* 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 */
switch (ret & 0xFF) {
case 0x18: /* CM3218 */
cm32181->num_als_it = ARRAY_SIZE(cm3218_als_it_bits);
cm32181->als_it_bits = cm3218_als_it_bits;
cm32181->als_it_values = cm3218_als_it_values;
break;
case 0x81: /* CM32181 */
case 0x82: /* CM32182, fully compat. with CM32181 */
cm32181->num_als_it = ARRAY_SIZE(cm32181_als_it_bits);
cm32181->als_it_bits = cm32181_als_it_bits;
cm32181->als_it_values = cm32181_als_it_values;
break;
default:
return -ENODEV;
}
/* Default Values */
cm32181->conf_regs[CM32181_REG_ADDR_CMD] =
CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT;
cm32181->init_regs_bitmap = BIT(CM32181_REG_ADDR_CMD);
cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT;
cm32181->lux_per_bit = CM32181_LUX_PER_BIT;
cm32181->lux_per_bit_base_it = CM32181_LUX_PER_BIT_BASE_IT;
if (ACPI_HANDLE(cm32181->dev))
cm32181_acpi_parse_cpm_tables(cm32181);
/* Initialize registers*/
for_each_set_bit(i, &cm32181->init_regs_bitmap, CM32181_CONF_REG_NUM) {
ret = i2c_smbus_write_word_data(client, 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 integration time in milliseconds.
*
* 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 < cm32181->num_als_it; i++) {
if (als_it == cm32181->als_it_bits[i]) {
*val2 = cm32181->als_it_values[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 = cm32181->num_als_it;
for (i = 0; i < n; i++)
if (val <= cm32181->als_it_values[i])
break;
if (i >= n)
i = n - 1;
als_it = cm32181->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;
u64 lux;
ret = cm32181_read_als_it(cm32181, &als_it);
if (ret < 0)
return -EINVAL;
lux = cm32181->lux_per_bit;
lux *= cm32181->lux_per_bit_base_it;
lux = div_u64(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 = div_u64(lux, CM32181_CALIBSCALE_RESOLUTION);
lux = div_u64(lux, CM32181_LUX_PER_BIT_RESOLUTION);
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)
{
struct cm32181_chip *cm32181 = iio_priv(dev_to_iio_dev(dev));
int i, n, len;
n = cm32181->num_als_it;
for (i = 0, len = 0; i < n; i++)
len += sprintf(buf + len, "0.%06u ", cm32181->als_it_values[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 = {
.read_raw = &cm32181_read_raw,
.write_raw = &cm32181_write_raw,
.attrs = &cm32181_attribute_group,
};
static int cm32181_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct cm32181_chip *cm32181;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*cm32181));
if (!indio_dev)
return -ENOMEM;
i2c_set_clientdata(client, indio_dev);
/*
* Some ACPI systems list 2 I2C resources for the CM3218 sensor, the
* SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address.
* Detect this and take the following step to deal with it:
* 1. When a SMBus Alert capable sensor has an Alert asserted, it will
* not respond on its actual I2C address. Read a byte from the ARA
* to clear any pending Alerts.
* 2. Create a "dummy" client for the actual I2C address and
* use that client to communicate with the sensor.
*/
if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) {
struct i2c_board_info board_info = { .type = "dummy" };
i2c_smbus_read_byte(client);
client = i2c_acpi_new_device(dev, 1, &board_info);
if (IS_ERR(client))
return PTR_ERR(client);
}
cm32181 = iio_priv(indio_dev);
cm32181->client = client;
cm32181->dev = dev;
mutex_init(&cm32181->lock);
indio_dev->channels = cm32181_channels;
indio_dev->num_channels = ARRAY_SIZE(cm32181_channels);
indio_dev->info = &cm32181_info;
indio_dev->name = dev_name(dev);
indio_dev->modes = INDIO_DIRECT_MODE;
ret = cm32181_reg_init(cm32181);
if (ret) {
dev_err(dev, "%s: register init failed\n", __func__);
return ret;
}
ret = devm_iio_device_register(dev, indio_dev);
if (ret) {
dev_err(dev, "%s: regist device failed\n", __func__);
return ret;
}
return 0;
}
static int cm32181_suspend(struct device *dev)
{
struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
struct i2c_client *client = cm32181->client;
return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
CM32181_CMD_ALS_DISABLE);
}
static int cm32181_resume(struct device *dev)
{
struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
struct i2c_client *client = cm32181->client;
return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
}
static DEFINE_SIMPLE_DEV_PM_OPS(cm32181_pm_ops, cm32181_suspend, cm32181_resume);
static const struct of_device_id cm32181_of_match[] = {
{ .compatible = "capella,cm3218" },
{ .compatible = "capella,cm32181" },
{ }
};
MODULE_DEVICE_TABLE(of, cm32181_of_match);
#ifdef CONFIG_ACPI
static const struct acpi_device_id cm32181_acpi_match[] = {
{ "CPLM3218", 0 },
{ }
};
MODULE_DEVICE_TABLE(acpi, cm32181_acpi_match);
#endif
static struct i2c_driver cm32181_driver = {
.driver = {
.name = "cm32181",
.acpi_match_table = ACPI_PTR(cm32181_acpi_match),
.of_match_table = cm32181_of_match,
.pm = pm_sleep_ptr(&cm32181_pm_ops),
},
.probe_new = cm32181_probe,
};
module_i2c_driver(cm32181_driver);
MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
MODULE_DESCRIPTION("CM32181 ambient light sensor driver");
MODULE_LICENSE("GPL");
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