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/mutex.h> 20 21 #include <linux/iio/iio.h> 22 #include <linux/iio/buffer.h> 23 #include <linux/iio/kfifo_buf.h> 24 25 #define ACPI_ALS_CLASS "als" 26 #define ACPI_ALS_DEVICE_NAME "acpi-als" 27 #define ACPI_ALS_NOTIFY_ILLUMINANCE 0x80 28 29 ACPI_MODULE_NAME("acpi-als"); 30 31 /* 32 * So far, there's only one channel in here, but the specification for 33 * ACPI0008 says there can be more to what the block can report. Like 34 * chromaticity and such. We are ready for incoming additions! 35 */ 36 static const struct iio_chan_spec acpi_als_channels[] = { 37 { 38 .type = IIO_LIGHT, 39 .scan_type = { 40 .sign = 's', 41 .realbits = 32, 42 .storagebits = 32, 43 }, 44 /* _RAW is here for backward ABI compatibility */ 45 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 46 BIT(IIO_CHAN_INFO_PROCESSED), 47 }, 48 }; 49 50 /* 51 * The event buffer contains timestamp and all the data from 52 * the ACPI0008 block. There are multiple, but so far we only 53 * support _ALI (illuminance). Once someone adds new channels 54 * to acpi_als_channels[], the evt_buffer below will grow 55 * automatically. 56 */ 57 #define ACPI_ALS_EVT_NR_SOURCES ARRAY_SIZE(acpi_als_channels) 58 #define ACPI_ALS_EVT_BUFFER_SIZE \ 59 (sizeof(s64) + (ACPI_ALS_EVT_NR_SOURCES * sizeof(s32))) 60 61 struct acpi_als { 62 struct acpi_device *device; 63 struct mutex lock; 64 65 s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE]; 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_EXCEPTION((AE_INFO, status, "Error reading ALS %s", prop)); 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 s32 *buffer = als->evt_buffer; 108 s64 time_ns = iio_get_time_ns(indio_dev); 109 s32 val; 110 int ret; 111 112 mutex_lock(&als->lock); 113 114 memset(buffer, 0, ACPI_ALS_EVT_BUFFER_SIZE); 115 116 switch (event) { 117 case ACPI_ALS_NOTIFY_ILLUMINANCE: 118 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val); 119 if (ret < 0) 120 goto out; 121 *buffer++ = val; 122 break; 123 default: 124 /* Unhandled event */ 125 dev_dbg(&device->dev, "Unhandled ACPI ALS event (%08x)!\n", 126 event); 127 goto out; 128 } 129 130 iio_push_to_buffers_with_timestamp(indio_dev, als->evt_buffer, time_ns); 131 132 out: 133 mutex_unlock(&als->lock); 134 } 135 136 static int acpi_als_read_raw(struct iio_dev *indio_dev, 137 struct iio_chan_spec const *chan, int *val, 138 int *val2, long mask) 139 { 140 struct acpi_als *als = iio_priv(indio_dev); 141 s32 temp_val; 142 int ret; 143 144 if ((mask != IIO_CHAN_INFO_PROCESSED) && (mask != IIO_CHAN_INFO_RAW)) 145 return -EINVAL; 146 147 /* we support only illumination (_ALI) so far. */ 148 if (chan->type != IIO_LIGHT) 149 return -EINVAL; 150 151 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &temp_val); 152 if (ret < 0) 153 return ret; 154 155 *val = temp_val; 156 157 return IIO_VAL_INT; 158 } 159 160 static const struct iio_info acpi_als_info = { 161 .read_raw = acpi_als_read_raw, 162 }; 163 164 static int acpi_als_add(struct acpi_device *device) 165 { 166 struct acpi_als *als; 167 struct iio_dev *indio_dev; 168 struct iio_buffer *buffer; 169 170 indio_dev = devm_iio_device_alloc(&device->dev, sizeof(*als)); 171 if (!indio_dev) 172 return -ENOMEM; 173 174 als = iio_priv(indio_dev); 175 176 device->driver_data = indio_dev; 177 als->device = device; 178 mutex_init(&als->lock); 179 180 indio_dev->name = ACPI_ALS_DEVICE_NAME; 181 indio_dev->info = &acpi_als_info; 182 indio_dev->modes = INDIO_BUFFER_SOFTWARE; 183 indio_dev->channels = acpi_als_channels; 184 indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels); 185 186 buffer = devm_iio_kfifo_allocate(&device->dev); 187 if (!buffer) 188 return -ENOMEM; 189 190 iio_device_attach_buffer(indio_dev, buffer); 191 192 return devm_iio_device_register(&device->dev, indio_dev); 193 } 194 195 static const struct acpi_device_id acpi_als_device_ids[] = { 196 {"ACPI0008", 0}, 197 {}, 198 }; 199 200 MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids); 201 202 static struct acpi_driver acpi_als_driver = { 203 .name = "acpi_als", 204 .class = ACPI_ALS_CLASS, 205 .ids = acpi_als_device_ids, 206 .ops = { 207 .add = acpi_als_add, 208 .notify = acpi_als_notify, 209 }, 210 }; 211 212 module_acpi_driver(acpi_als_driver); 213 214 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); 215 MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>"); 216 MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); 217 MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver"); 218 MODULE_LICENSE("GPL"); 219