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