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 #include <linux/platform_device.h> 22 23 #include <linux/iio/iio.h> 24 #include <linux/iio/buffer.h> 25 #include <linux/iio/trigger.h> 26 #include <linux/iio/triggered_buffer.h> 27 #include <linux/iio/trigger_consumer.h> 28 29 #define ACPI_ALS_CLASS "als" 30 #define ACPI_ALS_DEVICE_NAME "acpi-als" 31 #define ACPI_ALS_NOTIFY_ILLUMINANCE 0x80 32 33 /* 34 * So far, there's only one channel in here, but the specification for 35 * ACPI0008 says there can be more to what the block can report. Like 36 * chromaticity and such. We are ready for incoming additions! 37 */ 38 static const struct iio_chan_spec acpi_als_channels[] = { 39 { 40 .type = IIO_LIGHT, 41 .scan_type = { 42 .sign = 's', 43 .realbits = 32, 44 .storagebits = 32, 45 }, 46 /* _RAW is here for backward ABI compatibility */ 47 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 48 BIT(IIO_CHAN_INFO_PROCESSED), 49 }, 50 IIO_CHAN_SOFT_TIMESTAMP(1), 51 }; 52 53 struct acpi_als { 54 struct acpi_device *device; 55 struct mutex lock; 56 struct iio_trigger *trig; 57 }; 58 59 /* 60 * All types of properties the ACPI0008 block can report. The ALI, ALC, ALT 61 * and ALP can all be handled by acpi_als_read_value() below, while the ALR is 62 * special. 63 * 64 * The _ALR property returns tables that can be used to fine-tune the values 65 * reported by the other props based on the particular hardware type and it's 66 * location (it contains tables for "rainy", "bright inhouse lighting" etc.). 67 * 68 * So far, we support only ALI (illuminance). 69 */ 70 #define ACPI_ALS_ILLUMINANCE "_ALI" 71 #define ACPI_ALS_CHROMATICITY "_ALC" 72 #define ACPI_ALS_COLOR_TEMP "_ALT" 73 #define ACPI_ALS_POLLING "_ALP" 74 #define ACPI_ALS_TABLES "_ALR" 75 76 static int acpi_als_read_value(struct acpi_als *als, char *prop, s32 *val) 77 { 78 unsigned long long temp_val; 79 acpi_status status; 80 81 status = acpi_evaluate_integer(als->device->handle, prop, NULL, 82 &temp_val); 83 84 if (ACPI_FAILURE(status)) { 85 acpi_evaluation_failure_warn(als->device->handle, prop, status); 86 return -EIO; 87 } 88 89 *val = temp_val; 90 91 return 0; 92 } 93 94 static void acpi_als_notify(acpi_handle handle, u32 event, void *data) 95 { 96 struct iio_dev *indio_dev = data; 97 struct acpi_als *als = iio_priv(indio_dev); 98 99 if (iio_buffer_enabled(indio_dev) && iio_trigger_using_own(indio_dev)) { 100 switch (event) { 101 case ACPI_ALS_NOTIFY_ILLUMINANCE: 102 iio_trigger_poll_nested(als->trig); 103 break; 104 default: 105 /* Unhandled event */ 106 dev_dbg(&als->device->dev, 107 "Unhandled ACPI ALS event (%08x)!\n", 108 event); 109 } 110 } 111 } 112 113 static int acpi_als_read_raw(struct iio_dev *indio_dev, 114 struct iio_chan_spec const *chan, int *val, 115 int *val2, long mask) 116 { 117 struct acpi_als *als = iio_priv(indio_dev); 118 s32 temp_val; 119 int ret; 120 121 if ((mask != IIO_CHAN_INFO_PROCESSED) && (mask != IIO_CHAN_INFO_RAW)) 122 return -EINVAL; 123 124 /* we support only illumination (_ALI) so far. */ 125 if (chan->type != IIO_LIGHT) 126 return -EINVAL; 127 128 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &temp_val); 129 if (ret < 0) 130 return ret; 131 132 *val = temp_val; 133 134 return IIO_VAL_INT; 135 } 136 137 static const struct iio_info acpi_als_info = { 138 .read_raw = acpi_als_read_raw, 139 }; 140 141 static irqreturn_t acpi_als_trigger_handler(int irq, void *p) 142 { 143 struct iio_poll_func *pf = p; 144 struct iio_dev *indio_dev = pf->indio_dev; 145 struct acpi_als *als = iio_priv(indio_dev); 146 struct { 147 s32 light; 148 aligned_s64 ts; 149 } scan = { }; 150 s32 val; 151 int ret; 152 153 mutex_lock(&als->lock); 154 155 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val); 156 if (ret < 0) 157 goto out; 158 scan.light = val; 159 160 /* 161 * When coming from own trigger via polls, set polling function 162 * timestamp here. Given ACPI notifier is already in a thread and call 163 * function directly, there is no need to set the timestamp in the 164 * notify function. 165 * 166 * If the timestamp was actually 0, the timestamp is set one more time. 167 */ 168 if (!pf->timestamp) 169 pf->timestamp = iio_get_time_ns(indio_dev); 170 171 iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan), pf->timestamp); 172 out: 173 mutex_unlock(&als->lock); 174 iio_trigger_notify_done(indio_dev->trig); 175 176 return IRQ_HANDLED; 177 } 178 179 static int acpi_als_probe(struct platform_device *pdev) 180 { 181 struct device *dev = &pdev->dev; 182 struct acpi_device *device; 183 struct iio_dev *indio_dev; 184 struct acpi_als *als; 185 int ret; 186 187 device = ACPI_COMPANION(dev); 188 if (!device) 189 return -ENODEV; 190 191 indio_dev = devm_iio_device_alloc(dev, sizeof(*als)); 192 if (!indio_dev) 193 return -ENOMEM; 194 195 als = iio_priv(indio_dev); 196 197 als->device = device; 198 mutex_init(&als->lock); 199 200 indio_dev->name = ACPI_ALS_DEVICE_NAME; 201 indio_dev->info = &acpi_als_info; 202 indio_dev->channels = acpi_als_channels; 203 indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels); 204 205 als->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name, 206 iio_device_id(indio_dev)); 207 if (!als->trig) 208 return -ENOMEM; 209 210 ret = devm_iio_trigger_register(dev, als->trig); 211 if (ret) 212 return ret; 213 /* 214 * Set hardware trigger by default to let events flow when 215 * BIOS support notification. 216 */ 217 indio_dev->trig = iio_trigger_get(als->trig); 218 219 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, 220 iio_pollfunc_store_time, 221 acpi_als_trigger_handler, 222 NULL); 223 if (ret) 224 return ret; 225 226 ret = devm_iio_device_register(dev, indio_dev); 227 if (ret) 228 return ret; 229 230 return acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY, 231 acpi_als_notify, indio_dev); 232 } 233 234 static void acpi_als_remove(struct platform_device *pdev) 235 { 236 acpi_dev_remove_notify_handler(ACPI_COMPANION(&pdev->dev), 237 ACPI_DEVICE_NOTIFY, acpi_als_notify); 238 } 239 240 static const struct acpi_device_id acpi_als_device_ids[] = { 241 {"ACPI0008", 0}, 242 { } 243 }; 244 245 MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids); 246 247 static struct platform_driver acpi_als_driver = { 248 .probe = acpi_als_probe, 249 .remove = acpi_als_remove, 250 .driver = { 251 .name = "acpi_als", 252 .acpi_match_table = acpi_als_device_ids, 253 }, 254 }; 255 module_platform_driver(acpi_als_driver); 256 257 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); 258 MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>"); 259 MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); 260 MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver"); 261 MODULE_LICENSE("GPL"); 262