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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * ACPI Ambient Light Sensor Driver4 *5 * Based on ALS driver:6 * Copyright (C) 2009 Zhang Rui <rui.zhang@intel.com>7 *8 * Rework for IIO subsystem:9 * Copyright (C) 2012-2013 Martin Liska <marxin.liska@gmail.com>10 *11 * Final cleanup and debugging:12 * Copyright (C) 2013-2014 Marek Vasut <marex@denx.de>13 * Copyright (C) 2015 Gabriele Mazzotta <gabriele.mzt@gmail.com>14 */15 16#include <linux/module.h>17#include <linux/acpi.h>18#include <linux/err.h>19#include <linux/irq.h>20#include <linux/mutex.h>21 22#include <linux/iio/iio.h>23#include <linux/iio/buffer.h>24#include <linux/iio/trigger.h>25#include <linux/iio/triggered_buffer.h>26#include <linux/iio/trigger_consumer.h>27 28#define ACPI_ALS_CLASS "als"29#define ACPI_ALS_DEVICE_NAME "acpi-als"30#define ACPI_ALS_NOTIFY_ILLUMINANCE 0x8031 32/*33 * So far, there's only one channel in here, but the specification for34 * ACPI0008 says there can be more to what the block can report. Like35 * chromaticity and such. We are ready for incoming additions!36 */37static const struct iio_chan_spec acpi_als_channels[] = {38 {39 .type = IIO_LIGHT,40 .scan_type = {41 .sign = 's',42 .realbits = 32,43 .storagebits = 32,44 },45 /* _RAW is here for backward ABI compatibility */46 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |47 BIT(IIO_CHAN_INFO_PROCESSED),48 },49 IIO_CHAN_SOFT_TIMESTAMP(1),50};51 52/*53 * The event buffer contains timestamp and all the data from54 * the ACPI0008 block. There are multiple, but so far we only55 * support _ALI (illuminance): One channel, padding and timestamp.56 */57#define ACPI_ALS_EVT_BUFFER_SIZE \58 (sizeof(s32) + sizeof(s32) + sizeof(s64))59 60struct acpi_als {61 struct acpi_device *device;62 struct mutex lock;63 struct iio_trigger *trig;64 65 s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE / sizeof(s32)] __aligned(8);66};67 68/*69 * All types of properties the ACPI0008 block can report. The ALI, ALC, ALT70 * and ALP can all be handled by acpi_als_read_value() below, while the ALR is71 * special.72 *73 * The _ALR property returns tables that can be used to fine-tune the values74 * reported by the other props based on the particular hardware type and it's75 * location (it contains tables for "rainy", "bright inhouse lighting" etc.).76 *77 * So far, we support only ALI (illuminance).78 */79#define ACPI_ALS_ILLUMINANCE "_ALI"80#define ACPI_ALS_CHROMATICITY "_ALC"81#define ACPI_ALS_COLOR_TEMP "_ALT"82#define ACPI_ALS_POLLING "_ALP"83#define ACPI_ALS_TABLES "_ALR"84 85static int acpi_als_read_value(struct acpi_als *als, char *prop, s32 *val)86{87 unsigned long long temp_val;88 acpi_status status;89 90 status = acpi_evaluate_integer(als->device->handle, prop, NULL,91 &temp_val);92 93 if (ACPI_FAILURE(status)) {94 acpi_evaluation_failure_warn(als->device->handle, prop, status);95 return -EIO;96 }97 98 *val = temp_val;99 100 return 0;101}102 103static void acpi_als_notify(struct acpi_device *device, u32 event)104{105 struct iio_dev *indio_dev = acpi_driver_data(device);106 struct acpi_als *als = iio_priv(indio_dev);107 108 if (iio_buffer_enabled(indio_dev) && iio_trigger_using_own(indio_dev)) {109 switch (event) {110 case ACPI_ALS_NOTIFY_ILLUMINANCE:111 iio_trigger_poll_nested(als->trig);112 break;113 default:114 /* Unhandled event */115 dev_dbg(&device->dev,116 "Unhandled ACPI ALS event (%08x)!\n",117 event);118 }119 }120}121 122static int acpi_als_read_raw(struct iio_dev *indio_dev,123 struct iio_chan_spec const *chan, int *val,124 int *val2, long mask)125{126 struct acpi_als *als = iio_priv(indio_dev);127 s32 temp_val;128 int ret;129 130 if ((mask != IIO_CHAN_INFO_PROCESSED) && (mask != IIO_CHAN_INFO_RAW))131 return -EINVAL;132 133 /* we support only illumination (_ALI) so far. */134 if (chan->type != IIO_LIGHT)135 return -EINVAL;136 137 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &temp_val);138 if (ret < 0)139 return ret;140 141 *val = temp_val;142 143 return IIO_VAL_INT;144}145 146static const struct iio_info acpi_als_info = {147 .read_raw = acpi_als_read_raw,148};149 150static irqreturn_t acpi_als_trigger_handler(int irq, void *p)151{152 struct iio_poll_func *pf = p;153 struct iio_dev *indio_dev = pf->indio_dev;154 struct acpi_als *als = iio_priv(indio_dev);155 s32 *buffer = als->evt_buffer;156 s32 val;157 int ret;158 159 mutex_lock(&als->lock);160 161 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val);162 if (ret < 0)163 goto out;164 *buffer = val;165 166 /*167 * When coming from own trigger via polls, set polling function168 * timestamp here. Given ACPI notifier is already in a thread and call169 * function directly, there is no need to set the timestamp in the170 * notify function.171 *172 * If the timestamp was actually 0, the timestamp is set one more time.173 */174 if (!pf->timestamp)175 pf->timestamp = iio_get_time_ns(indio_dev);176 177 iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);178out:179 mutex_unlock(&als->lock);180 iio_trigger_notify_done(indio_dev->trig);181 182 return IRQ_HANDLED;183}184 185static int acpi_als_add(struct acpi_device *device)186{187 struct device *dev = &device->dev;188 struct iio_dev *indio_dev;189 struct acpi_als *als;190 int ret;191 192 indio_dev = devm_iio_device_alloc(dev, sizeof(*als));193 if (!indio_dev)194 return -ENOMEM;195 196 als = iio_priv(indio_dev);197 198 device->driver_data = indio_dev;199 als->device = device;200 mutex_init(&als->lock);201 202 indio_dev->name = ACPI_ALS_DEVICE_NAME;203 indio_dev->info = &acpi_als_info;204 indio_dev->channels = acpi_als_channels;205 indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels);206 207 als->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,208 iio_device_id(indio_dev));209 if (!als->trig)210 return -ENOMEM;211 212 ret = devm_iio_trigger_register(dev, als->trig);213 if (ret)214 return ret;215 /*216 * Set hardware trigger by default to let events flow when217 * BIOS support notification.218 */219 indio_dev->trig = iio_trigger_get(als->trig);220 221 ret = devm_iio_triggered_buffer_setup(dev, indio_dev,222 iio_pollfunc_store_time,223 acpi_als_trigger_handler,224 NULL);225 if (ret)226 return ret;227 228 return devm_iio_device_register(dev, indio_dev);229}230 231static const struct acpi_device_id acpi_als_device_ids[] = {232 {"ACPI0008", 0},233 {},234};235 236MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids);237 238static struct acpi_driver acpi_als_driver = {239 .name = "acpi_als",240 .class = ACPI_ALS_CLASS,241 .ids = acpi_als_device_ids,242 .ops = {243 .add = acpi_als_add,244 .notify = acpi_als_notify,245 },246};247 248module_acpi_driver(acpi_als_driver);249 250MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");251MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>");252MODULE_AUTHOR("Marek Vasut <marex@denx.de>");253MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver");254MODULE_LICENSE("GPL");255