diff options
Diffstat (limited to 'drivers/iio/light/us5182d.c')
| -rw-r--r-- | drivers/iio/light/us5182d.c | 507 |
1 files changed, 507 insertions, 0 deletions
diff --git a/drivers/iio/light/us5182d.c b/drivers/iio/light/us5182d.c new file mode 100644 index 000000000..49dab3cb3 --- /dev/null +++ b/drivers/iio/light/us5182d.c @@ -0,0 +1,507 @@ +/* + * Copyright (c) 2015 Intel Corporation + * + * Driver for UPISEMI us5182d Proximity and Ambient Light Sensor. + * + * 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. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * To do: Interrupt support. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/acpi.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/mutex.h> + +#define US5182D_REG_CFG0 0x00 +#define US5182D_CFG0_ONESHOT_EN BIT(6) +#define US5182D_CFG0_SHUTDOWN_EN BIT(7) +#define US5182D_CFG0_WORD_ENABLE BIT(0) + +#define US5182D_REG_CFG1 0x01 +#define US5182D_CFG1_ALS_RES16 BIT(4) +#define US5182D_CFG1_AGAIN_DEFAULT 0x00 + +#define US5182D_REG_CFG2 0x02 +#define US5182D_CFG2_PX_RES16 BIT(4) +#define US5182D_CFG2_PXGAIN_DEFAULT BIT(2) + +#define US5182D_REG_CFG3 0x03 +#define US5182D_CFG3_LED_CURRENT100 (BIT(4) | BIT(5)) + +#define US5182D_REG_CFG4 0x10 + +/* + * Registers for tuning the auto dark current cancelling feature. + * DARK_TH(reg 0x27,0x28) - threshold (counts) for auto dark cancelling. + * when ALS > DARK_TH --> ALS_Code = ALS - Upper(0x2A) * Dark + * when ALS < DARK_TH --> ALS_Code = ALS - Lower(0x29) * Dark + */ +#define US5182D_REG_UDARK_TH 0x27 +#define US5182D_REG_DARK_AUTO_EN 0x2b +#define US5182D_REG_AUTO_LDARK_GAIN 0x29 +#define US5182D_REG_AUTO_HDARK_GAIN 0x2a + +#define US5182D_OPMODE_ALS 0x01 +#define US5182D_OPMODE_PX 0x02 +#define US5182D_OPMODE_SHIFT 4 + +#define US5182D_REG_DARK_AUTO_EN_DEFAULT 0x80 +#define US5182D_REG_AUTO_LDARK_GAIN_DEFAULT 0x16 +#define US5182D_REG_AUTO_HDARK_GAIN_DEFAULT 0x00 + +#define US5182D_REG_ADL 0x0c +#define US5182D_REG_PDL 0x0e + +#define US5182D_REG_MODE_STORE 0x21 +#define US5182D_STORE_MODE 0x01 + +#define US5182D_REG_CHIPID 0xb2 + +#define US5182D_OPMODE_MASK GENMASK(5, 4) +#define US5182D_AGAIN_MASK 0x07 +#define US5182D_RESET_CHIP 0x01 + +#define US5182D_CHIPID 0x26 +#define US5182D_DRV_NAME "us5182d" + +#define US5182D_GA_RESOLUTION 1000 + +#define US5182D_READ_BYTE 1 +#define US5182D_READ_WORD 2 +#define US5182D_OPSTORE_SLEEP_TIME 20 /* ms */ + +/* Available ranges: [12354, 7065, 3998, 2202, 1285, 498, 256, 138] lux */ +static const int us5182d_scales[] = {188500, 107800, 61000, 33600, 19600, 7600, + 3900, 2100}; + +/* + * Experimental thresholds that work with US5182D sensor on evaluation board + * roughly between 12-32 lux + */ +static u16 us5182d_dark_ths_vals[] = {170, 200, 512, 512, 800, 2000, 4000, + 8000}; + +enum mode { + US5182D_ALS_PX, + US5182D_ALS_ONLY, + US5182D_PX_ONLY +}; + +struct us5182d_data { + struct i2c_client *client; + struct mutex lock; + + /* Glass attenuation factor */ + u32 ga; + + /* Dark gain tuning */ + u8 lower_dark_gain; + u8 upper_dark_gain; + u16 *us5182d_dark_ths; + + u8 opmode; +}; + +static IIO_CONST_ATTR(in_illuminance_scale_available, + "0.0021 0.0039 0.0076 0.0196 0.0336 0.061 0.1078 0.1885"); + +static struct attribute *us5182d_attrs[] = { + &iio_const_attr_in_illuminance_scale_available.dev_attr.attr, + NULL +}; + +static const struct attribute_group us5182d_attr_group = { + .attrs = us5182d_attrs, +}; + +static const struct { + u8 reg; + u8 val; +} us5182d_regvals[] = { + {US5182D_REG_CFG0, (US5182D_CFG0_SHUTDOWN_EN | + US5182D_CFG0_WORD_ENABLE)}, + {US5182D_REG_CFG1, US5182D_CFG1_ALS_RES16}, + {US5182D_REG_CFG2, (US5182D_CFG2_PX_RES16 | + US5182D_CFG2_PXGAIN_DEFAULT)}, + {US5182D_REG_CFG3, US5182D_CFG3_LED_CURRENT100}, + {US5182D_REG_MODE_STORE, US5182D_STORE_MODE}, + {US5182D_REG_CFG4, 0x00}, +}; + +static const struct iio_chan_spec us5182d_channels[] = { + { + .type = IIO_LIGHT, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + }, + { + .type = IIO_PROXIMITY, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + } +}; + +static int us5182d_get_als(struct us5182d_data *data) +{ + int ret; + unsigned long result; + + ret = i2c_smbus_read_word_data(data->client, + US5182D_REG_ADL); + if (ret < 0) + return ret; + + result = ret * data->ga / US5182D_GA_RESOLUTION; + if (result > 0xffff) + result = 0xffff; + + return result; +} + +static int us5182d_set_opmode(struct us5182d_data *data, u8 mode) +{ + int ret; + + ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG0); + if (ret < 0) + return ret; + + /* + * In oneshot mode the chip will power itself down after taking the + * required measurement. + */ + ret = ret | US5182D_CFG0_ONESHOT_EN; + + /* update mode */ + ret = ret & ~US5182D_OPMODE_MASK; + ret = ret | (mode << US5182D_OPMODE_SHIFT); + + /* + * After updating the operating mode, the chip requires that + * the operation is stored, by writing 1 in the STORE_MODE + * register (auto-clearing). + */ + ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG0, ret); + if (ret < 0) + return ret; + + if (mode == data->opmode) + return 0; + + ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_MODE_STORE, + US5182D_STORE_MODE); + if (ret < 0) + return ret; + + data->opmode = mode; + msleep(US5182D_OPSTORE_SLEEP_TIME); + + return 0; +} + +static int us5182d_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct us5182d_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + switch (chan->type) { + case IIO_LIGHT: + mutex_lock(&data->lock); + ret = us5182d_set_opmode(data, US5182D_OPMODE_ALS); + if (ret < 0) + goto out_err; + + ret = us5182d_get_als(data); + if (ret < 0) + goto out_err; + mutex_unlock(&data->lock); + *val = ret; + return IIO_VAL_INT; + case IIO_PROXIMITY: + mutex_lock(&data->lock); + ret = us5182d_set_opmode(data, US5182D_OPMODE_PX); + if (ret < 0) + goto out_err; + + ret = i2c_smbus_read_word_data(data->client, + US5182D_REG_PDL); + if (ret < 0) + goto out_err; + mutex_unlock(&data->lock); + *val = ret; + return IIO_VAL_INT; + default: + return -EINVAL; + } + + case IIO_CHAN_INFO_SCALE: + ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG1); + if (ret < 0) + return ret; + + *val = 0; + *val2 = us5182d_scales[ret & US5182D_AGAIN_MASK]; + + return IIO_VAL_INT_PLUS_MICRO; + default: + return -EINVAL; + } + + return -EINVAL; +out_err: + mutex_unlock(&data->lock); + return ret; +} + +/** + * us5182d_update_dark_th - update Darh_Th registers + * @data us5182d_data structure + * @index index in us5182d_dark_ths array to use for the updated value + * + * Function needs to be called with a lock held because it needs two i2c write + * byte operations as these registers (0x27 0x28) don't work in word mode + * accessing. + */ +static int us5182d_update_dark_th(struct us5182d_data *data, int index) +{ + __be16 dark_th = cpu_to_be16(data->us5182d_dark_ths[index]); + int ret; + + ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_UDARK_TH, + ((u8 *)&dark_th)[0]); + if (ret < 0) + return ret; + + return i2c_smbus_write_byte_data(data->client, US5182D_REG_UDARK_TH + 1, + ((u8 *)&dark_th)[1]); +} + +/** + * us5182d_apply_scale - update the ALS scale + * @data us5182d_data structure + * @index index in us5182d_scales array to use for the updated value + * + * Function needs to be called with a lock held as we're having more than one + * i2c operation. + */ +static int us5182d_apply_scale(struct us5182d_data *data, int index) +{ + int ret; + + ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG1); + if (ret < 0) + return ret; + + ret = ret & (~US5182D_AGAIN_MASK); + ret |= index; + + ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG1, ret); + if (ret < 0) + return ret; + + return us5182d_update_dark_th(data, index); +} + +static int us5182d_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, + int val2, long mask) +{ + struct us5182d_data *data = iio_priv(indio_dev); + int ret, i; + + switch (mask) { + case IIO_CHAN_INFO_SCALE: + if (val != 0) + return -EINVAL; + for (i = 0; i < ARRAY_SIZE(us5182d_scales); i++) + if (val2 == us5182d_scales[i]) { + mutex_lock(&data->lock); + ret = us5182d_apply_scale(data, i); + mutex_unlock(&data->lock); + return ret; + } + break; + default: + return -EINVAL; + } + + return -EINVAL; +} + +static const struct iio_info us5182d_info = { + .driver_module = THIS_MODULE, + .read_raw = us5182d_read_raw, + .write_raw = us5182d_write_raw, + .attrs = &us5182d_attr_group, +}; + +static int us5182d_reset(struct iio_dev *indio_dev) +{ + struct us5182d_data *data = iio_priv(indio_dev); + + return i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG3, + US5182D_RESET_CHIP); +} + +static int us5182d_init(struct iio_dev *indio_dev) +{ + struct us5182d_data *data = iio_priv(indio_dev); + int i, ret; + + ret = us5182d_reset(indio_dev); + if (ret < 0) + return ret; + + data->opmode = 0; + for (i = 0; i < ARRAY_SIZE(us5182d_regvals); i++) { + ret = i2c_smbus_write_byte_data(data->client, + us5182d_regvals[i].reg, + us5182d_regvals[i].val); + if (ret < 0) + return ret; + } + + return 0; +} + +static void us5182d_get_platform_data(struct iio_dev *indio_dev) +{ + struct us5182d_data *data = iio_priv(indio_dev); + + if (device_property_read_u32(&data->client->dev, "upisemi,glass-coef", + &data->ga)) + data->ga = US5182D_GA_RESOLUTION; + if (device_property_read_u16_array(&data->client->dev, + "upisemi,dark-ths", + data->us5182d_dark_ths, + ARRAY_SIZE(us5182d_dark_ths_vals))) + data->us5182d_dark_ths = us5182d_dark_ths_vals; + if (device_property_read_u8(&data->client->dev, + "upisemi,upper-dark-gain", + &data->upper_dark_gain)) + data->upper_dark_gain = US5182D_REG_AUTO_HDARK_GAIN_DEFAULT; + if (device_property_read_u8(&data->client->dev, + "upisemi,lower-dark-gain", + &data->lower_dark_gain)) + data->lower_dark_gain = US5182D_REG_AUTO_LDARK_GAIN_DEFAULT; +} + +static int us5182d_dark_gain_config(struct iio_dev *indio_dev) +{ + struct us5182d_data *data = iio_priv(indio_dev); + int ret; + + ret = us5182d_update_dark_th(data, US5182D_CFG1_AGAIN_DEFAULT); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_byte_data(data->client, + US5182D_REG_AUTO_LDARK_GAIN, + data->lower_dark_gain); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_byte_data(data->client, + US5182D_REG_AUTO_HDARK_GAIN, + data->upper_dark_gain); + if (ret < 0) + return ret; + + return i2c_smbus_write_byte_data(data->client, US5182D_REG_DARK_AUTO_EN, + US5182D_REG_DARK_AUTO_EN_DEFAULT); +} + +static int us5182d_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct us5182d_data *data; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->client = client; + + mutex_init(&data->lock); + + indio_dev->dev.parent = &client->dev; + indio_dev->info = &us5182d_info; + indio_dev->name = US5182D_DRV_NAME; + indio_dev->channels = us5182d_channels; + indio_dev->num_channels = ARRAY_SIZE(us5182d_channels); + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CHIPID); + if (ret != US5182D_CHIPID) { + dev_err(&data->client->dev, + "Failed to detect US5182 light chip\n"); + return (ret < 0) ? ret : -ENODEV; + } + + us5182d_get_platform_data(indio_dev); + ret = us5182d_init(indio_dev); + if (ret < 0) + return ret; + + ret = us5182d_dark_gain_config(indio_dev); + if (ret < 0) + return ret; + + return iio_device_register(indio_dev); +} + +static int us5182d_remove(struct i2c_client *client) +{ + iio_device_unregister(i2c_get_clientdata(client)); + return i2c_smbus_write_byte_data(client, US5182D_REG_CFG0, + US5182D_CFG0_SHUTDOWN_EN); +} + +static const struct acpi_device_id us5182d_acpi_match[] = { + { "USD5182", 0}, + {} +}; + +MODULE_DEVICE_TABLE(acpi, us5182d_acpi_match); + +static const struct i2c_device_id us5182d_id[] = { + {"usd5182", 0}, + {} +}; + +MODULE_DEVICE_TABLE(i2c, us5182d_id); + +static struct i2c_driver us5182d_driver = { + .driver = { + .name = US5182D_DRV_NAME, + .acpi_match_table = ACPI_PTR(us5182d_acpi_match), + }, + .probe = us5182d_probe, + .remove = us5182d_remove, + .id_table = us5182d_id, + +}; +module_i2c_driver(us5182d_driver); + +MODULE_AUTHOR("Adriana Reus <adriana.reus@intel.com>"); +MODULE_DESCRIPTION("Driver for us5182d Proximity and Light Sensor"); +MODULE_LICENSE("GPL v2"); |