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 ACPI_MODULE_NAME("acpi-als"); 33 34 /* 35 * So far, there's only one channel in here, but the specification for 36 * ACPI0008 says there can be more to what the block can report. Like 37 * chromaticity and such. We are ready for incoming additions! 38 */ 39 static const struct iio_chan_spec acpi_als_channels[] = { 40 { 41 .type = IIO_LIGHT, 42 .scan_type = { 43 .sign = 's', 44 .realbits = 32, 45 .storagebits = 32, 46 }, 47 /* _RAW is here for backward ABI compatibility */ 48 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 49 BIT(IIO_CHAN_INFO_PROCESSED), 50 }, 51 IIO_CHAN_SOFT_TIMESTAMP(1), 52 }; 53 54 /* 55 * The event buffer contains timestamp and all the data from 56 * the ACPI0008 block. There are multiple, but so far we only 57 * support _ALI (illuminance): One channel, padding and timestamp. 58 */ 59 #define ACPI_ALS_EVT_BUFFER_SIZE \ 60 (sizeof(s32) + sizeof(s32) + sizeof(s64)) 61 62 struct acpi_als { 63 struct acpi_device *device; 64 struct mutex lock; 65 struct iio_trigger *trig; 66 67 s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE / sizeof(s32)] __aligned(8); 68 }; 69 70 /* 71 * All types of properties the ACPI0008 block can report. The ALI, ALC, ALT 72 * and ALP can all be handled by acpi_als_read_value() below, while the ALR is 73 * special. 74 * 75 * The _ALR property returns tables that can be used to fine-tune the values 76 * reported by the other props based on the particular hardware type and it's 77 * location (it contains tables for "rainy", "bright inhouse lighting" etc.). 78 * 79 * So far, we support only ALI (illuminance). 80 */ 81 #define ACPI_ALS_ILLUMINANCE "_ALI" 82 #define ACPI_ALS_CHROMATICITY "_ALC" 83 #define ACPI_ALS_COLOR_TEMP "_ALT" 84 #define ACPI_ALS_POLLING "_ALP" 85 #define ACPI_ALS_TABLES "_ALR" 86 87 static int acpi_als_read_value(struct acpi_als *als, char *prop, s32 *val) 88 { 89 unsigned long long temp_val; 90 acpi_status status; 91 92 status = acpi_evaluate_integer(als->device->handle, prop, NULL, 93 &temp_val); 94 95 if (ACPI_FAILURE(status)) { 96 ACPI_EXCEPTION((AE_INFO, status, "Error reading ALS %s", prop)); 97 return -EIO; 98 } 99 100 *val = temp_val; 101 102 return 0; 103 } 104 105 static void acpi_als_notify(struct acpi_device *device, u32 event) 106 { 107 struct iio_dev *indio_dev = acpi_driver_data(device); 108 struct acpi_als *als = iio_priv(indio_dev); 109 110 if (iio_buffer_enabled(indio_dev) && iio_trigger_using_own(indio_dev)) { 111 switch (event) { 112 case ACPI_ALS_NOTIFY_ILLUMINANCE: 113 iio_trigger_poll_chained(als->trig); 114 break; 115 default: 116 /* Unhandled event */ 117 dev_dbg(&device->dev, 118 "Unhandled ACPI ALS event (%08x)!\n", 119 event); 120 } 121 } 122 } 123 124 static int acpi_als_read_raw(struct iio_dev *indio_dev, 125 struct iio_chan_spec const *chan, int *val, 126 int *val2, long mask) 127 { 128 struct acpi_als *als = iio_priv(indio_dev); 129 s32 temp_val; 130 int ret; 131 132 if ((mask != IIO_CHAN_INFO_PROCESSED) && (mask != IIO_CHAN_INFO_RAW)) 133 return -EINVAL; 134 135 /* we support only illumination (_ALI) so far. */ 136 if (chan->type != IIO_LIGHT) 137 return -EINVAL; 138 139 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &temp_val); 140 if (ret < 0) 141 return ret; 142 143 *val = temp_val; 144 145 return IIO_VAL_INT; 146 } 147 148 static const struct iio_info acpi_als_info = { 149 .read_raw = acpi_als_read_raw, 150 }; 151 152 static irqreturn_t acpi_als_trigger_handler(int irq, void *p) 153 { 154 struct iio_poll_func *pf = p; 155 struct iio_dev *indio_dev = pf->indio_dev; 156 struct acpi_als *als = iio_priv(indio_dev); 157 s32 *buffer = als->evt_buffer; 158 s32 val; 159 int ret; 160 161 mutex_lock(&als->lock); 162 163 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val); 164 if (ret < 0) 165 goto out; 166 *buffer = val; 167 168 /* 169 * When coming from own trigger via polls, set polling function 170 * timestamp here. Given ACPI notifier is already in a thread and call 171 * function directly, there is no need to set the timestamp in the 172 * notify function. 173 * 174 * If the timestamp was actually 0, the timestamp is set one more time. 175 */ 176 if (!pf->timestamp) 177 pf->timestamp = iio_get_time_ns(indio_dev); 178 179 iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp); 180 out: 181 mutex_unlock(&als->lock); 182 iio_trigger_notify_done(indio_dev->trig); 183 184 return IRQ_HANDLED; 185 } 186 187 static int acpi_als_add(struct acpi_device *device) 188 { 189 struct device *dev = &device->dev; 190 struct iio_dev *indio_dev; 191 struct acpi_als *als; 192 int ret; 193 194 indio_dev = devm_iio_device_alloc(dev, sizeof(*als)); 195 if (!indio_dev) 196 return -ENOMEM; 197 198 als = iio_priv(indio_dev); 199 200 device->driver_data = indio_dev; 201 als->device = device; 202 mutex_init(&als->lock); 203 204 indio_dev->name = ACPI_ALS_DEVICE_NAME; 205 indio_dev->info = &acpi_als_info; 206 indio_dev->channels = acpi_als_channels; 207 indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels); 208 209 als->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name, indio_dev->id); 210 if (!als->trig) 211 return -ENOMEM; 212 213 ret = devm_iio_trigger_register(dev, als->trig); 214 if (ret) 215 return ret; 216 /* 217 * Set hardware trigger by default to let events flow when 218 * BIOS support notification. 219 */ 220 indio_dev->trig = iio_trigger_get(als->trig); 221 222 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, 223 iio_pollfunc_store_time, 224 acpi_als_trigger_handler, 225 NULL); 226 if (ret) 227 return ret; 228 229 return devm_iio_device_register(dev, indio_dev); 230 } 231 232 static const struct acpi_device_id acpi_als_device_ids[] = { 233 {"ACPI0008", 0}, 234 {}, 235 }; 236 237 MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids); 238 239 static struct acpi_driver acpi_als_driver = { 240 .name = "acpi_als", 241 .class = ACPI_ALS_CLASS, 242 .ids = acpi_als_device_ids, 243 .ops = { 244 .add = acpi_als_add, 245 .notify = acpi_als_notify, 246 }, 247 }; 248 249 module_acpi_driver(acpi_als_driver); 250 251 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); 252 MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>"); 253 MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); 254 MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver"); 255 MODULE_LICENSE("GPL"); 256