1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ACPI Ambient Light Sensor Driver 4 * 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 0x80 31 32 /* 33 * So far, there's only one channel in here, but the specification for 34 * ACPI0008 says there can be more to what the block can report. Like 35 * chromaticity and such. We are ready for incoming additions! 36 */ 37 static 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 from 54 * the ACPI0008 block. There are multiple, but so far we only 55 * support _ALI (illuminance): One channel, padding and timestamp. 56 */ 57 #define ACPI_ALS_EVT_BUFFER_SIZE \ 58 (sizeof(s32) + sizeof(s32) + sizeof(s64)) 59 60 struct 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, ALT 70 * and ALP can all be handled by acpi_als_read_value() below, while the ALR is 71 * special. 72 * 73 * The _ALR property returns tables that can be used to fine-tune the values 74 * reported by the other props based on the particular hardware type and it's 75 * 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 85 static 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 } 102 103 static 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 } 121 122 static 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 } 145 146 static const struct iio_info acpi_als_info = { 147 .read_raw = acpi_als_read_raw, 148 }; 149 150 static 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 function 168 * timestamp here. Given ACPI notifier is already in a thread and call 169 * function directly, there is no need to set the timestamp in the 170 * 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); 178 out: 179 mutex_unlock(&als->lock); 180 iio_trigger_notify_done(indio_dev->trig); 181 182 return IRQ_HANDLED; 183 } 184 185 static 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 when 217 * 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 } 230 231 static const struct acpi_device_id acpi_als_device_ids[] = { 232 {"ACPI0008", 0}, 233 {}, 234 }; 235 236 MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids); 237 238 static 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 }; 247 248 module_acpi_driver(acpi_als_driver); 249 250 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); 251 MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>"); 252 MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); 253 MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver"); 254 MODULE_LICENSE("GPL"); 255