diff options
Diffstat (limited to 'drivers/iio/light/cm32181.c')
| -rw-r--r-- | drivers/iio/light/cm32181.c | 552 |
1 files changed, 552 insertions, 0 deletions
diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c new file mode 100644 index 000000000..d4a34a3bf --- /dev/null +++ b/drivers/iio/light/cm32181.c @@ -0,0 +1,552 @@ +// 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 void cm32181_unregister_dummy_client(void *data) +{ + struct i2c_client *client = data; + + /* Unregister the dummy client */ + i2c_unregister_device(client); +} + +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); + + ret = devm_add_action_or_reset(dev, cm32181_unregister_dummy_client, client); + if (ret) + return ret; + } + + 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"); |