1 /* 2 * ACPI Ambient Light Sensor Driver 3 * 4 * Based on ALS driver: 5 * Copyright (C) 2009 Zhang Rui <rui.zhang@intel.com> 6 * 7 * Rework for IIO subsystem: 8 * Copyright (C) 2012-2013 Martin Liska <marxin.liska@gmail.com> 9 * 10 * Final cleanup and debugging: 11 * Copyright (C) 2013-2014 Marek Vasut <marex@denx.de> 12 * Copyright (C) 2015 Gabriele Mazzotta <gabriele.mzt@gmail.com> 13 * 14 * This program is free software; you can redistribute it and/or modify it 15 * under the terms of the GNU General Public License as published by the 16 * Free Software Foundation; either version 2 of the License, or (at your 17 * option) any later version. 18 * 19 * This program is distributed in the hope that it will be useful, but 20 * WITHOUT ANY WARRANTY; without even the implied warranty of 21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 22 * General Public License for more details. 23 * 24 * You should have received a copy of the GNU General Public License along 25 * with this program; if not, write to the Free Software Foundation, Inc., 26 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 27 */ 28 29 #include <linux/module.h> 30 #include <linux/acpi.h> 31 #include <linux/err.h> 32 #include <linux/mutex.h> 33 34 #include <linux/iio/iio.h> 35 #include <linux/iio/buffer.h> 36 #include <linux/iio/kfifo_buf.h> 37 38 #define ACPI_ALS_CLASS "als" 39 #define ACPI_ALS_DEVICE_NAME "acpi-als" 40 #define ACPI_ALS_NOTIFY_ILLUMINANCE 0x80 41 42 ACPI_MODULE_NAME("acpi-als"); 43 44 /* 45 * So far, there's only one channel in here, but the specification for 46 * ACPI0008 says there can be more to what the block can report. Like 47 * chromaticity and such. We are ready for incoming additions! 48 */ 49 static const struct iio_chan_spec acpi_als_channels[] = { 50 { 51 .type = IIO_LIGHT, 52 .scan_type = { 53 .sign = 's', 54 .realbits = 32, 55 .storagebits = 32, 56 }, 57 /* _RAW is here for backward ABI compatibility */ 58 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 59 BIT(IIO_CHAN_INFO_PROCESSED), 60 }, 61 }; 62 63 /* 64 * The event buffer contains timestamp and all the data from 65 * the ACPI0008 block. There are multiple, but so far we only 66 * support _ALI (illuminance). Once someone adds new channels 67 * to acpi_als_channels[], the evt_buffer below will grow 68 * automatically. 69 */ 70 #define ACPI_ALS_EVT_NR_SOURCES ARRAY_SIZE(acpi_als_channels) 71 #define ACPI_ALS_EVT_BUFFER_SIZE \ 72 (sizeof(s64) + (ACPI_ALS_EVT_NR_SOURCES * sizeof(s32))) 73 74 struct acpi_als { 75 struct acpi_device *device; 76 struct mutex lock; 77 78 s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE]; 79 }; 80 81 /* 82 * All types of properties the ACPI0008 block can report. The ALI, ALC, ALT 83 * and ALP can all be handled by acpi_als_read_value() below, while the ALR is 84 * special. 85 * 86 * The _ALR property returns tables that can be used to fine-tune the values 87 * reported by the other props based on the particular hardware type and it's 88 * location (it contains tables for "rainy", "bright inhouse lighting" etc.). 89 * 90 * So far, we support only ALI (illuminance). 91 */ 92 #define ACPI_ALS_ILLUMINANCE "_ALI" 93 #define ACPI_ALS_CHROMATICITY "_ALC" 94 #define ACPI_ALS_COLOR_TEMP "_ALT" 95 #define ACPI_ALS_POLLING "_ALP" 96 #define ACPI_ALS_TABLES "_ALR" 97 98 static int acpi_als_read_value(struct acpi_als *als, char *prop, s32 *val) 99 { 100 unsigned long long temp_val; 101 acpi_status status; 102 103 status = acpi_evaluate_integer(als->device->handle, prop, NULL, 104 &temp_val); 105 106 if (ACPI_FAILURE(status)) { 107 ACPI_EXCEPTION((AE_INFO, status, "Error reading ALS %s", prop)); 108 return -EIO; 109 } 110 111 *val = temp_val; 112 113 return 0; 114 } 115 116 static void acpi_als_notify(struct acpi_device *device, u32 event) 117 { 118 struct iio_dev *indio_dev = acpi_driver_data(device); 119 struct acpi_als *als = iio_priv(indio_dev); 120 s32 *buffer = als->evt_buffer; 121 s64 time_ns = iio_get_time_ns(indio_dev); 122 s32 val; 123 int ret; 124 125 mutex_lock(&als->lock); 126 127 memset(buffer, 0, ACPI_ALS_EVT_BUFFER_SIZE); 128 129 switch (event) { 130 case ACPI_ALS_NOTIFY_ILLUMINANCE: 131 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val); 132 if (ret < 0) 133 goto out; 134 *buffer++ = val; 135 break; 136 default: 137 /* Unhandled event */ 138 dev_dbg(&device->dev, "Unhandled ACPI ALS event (%08x)!\n", 139 event); 140 goto out; 141 } 142 143 iio_push_to_buffers_with_timestamp(indio_dev, als->evt_buffer, time_ns); 144 145 out: 146 mutex_unlock(&als->lock); 147 } 148 149 static int acpi_als_read_raw(struct iio_dev *indio_dev, 150 struct iio_chan_spec const *chan, int *val, 151 int *val2, long mask) 152 { 153 struct acpi_als *als = iio_priv(indio_dev); 154 s32 temp_val; 155 int ret; 156 157 if ((mask != IIO_CHAN_INFO_PROCESSED) && (mask != IIO_CHAN_INFO_RAW)) 158 return -EINVAL; 159 160 /* we support only illumination (_ALI) so far. */ 161 if (chan->type != IIO_LIGHT) 162 return -EINVAL; 163 164 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &temp_val); 165 if (ret < 0) 166 return ret; 167 168 *val = temp_val; 169 170 return IIO_VAL_INT; 171 } 172 173 static const struct iio_info acpi_als_info = { 174 .read_raw = acpi_als_read_raw, 175 }; 176 177 static int acpi_als_add(struct acpi_device *device) 178 { 179 struct acpi_als *als; 180 struct iio_dev *indio_dev; 181 struct iio_buffer *buffer; 182 183 indio_dev = devm_iio_device_alloc(&device->dev, sizeof(*als)); 184 if (!indio_dev) 185 return -ENOMEM; 186 187 als = iio_priv(indio_dev); 188 189 device->driver_data = indio_dev; 190 als->device = device; 191 mutex_init(&als->lock); 192 193 indio_dev->name = ACPI_ALS_DEVICE_NAME; 194 indio_dev->dev.parent = &device->dev; 195 indio_dev->info = &acpi_als_info; 196 indio_dev->modes = INDIO_BUFFER_SOFTWARE; 197 indio_dev->channels = acpi_als_channels; 198 indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels); 199 200 buffer = devm_iio_kfifo_allocate(&device->dev); 201 if (!buffer) 202 return -ENOMEM; 203 204 iio_device_attach_buffer(indio_dev, buffer); 205 206 return devm_iio_device_register(&device->dev, indio_dev); 207 } 208 209 static const struct acpi_device_id acpi_als_device_ids[] = { 210 {"ACPI0008", 0}, 211 {}, 212 }; 213 214 MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids); 215 216 static struct acpi_driver acpi_als_driver = { 217 .name = "acpi_als", 218 .class = ACPI_ALS_CLASS, 219 .ids = acpi_als_device_ids, 220 .ops = { 221 .add = acpi_als_add, 222 .notify = acpi_als_notify, 223 }, 224 }; 225 226 module_acpi_driver(acpi_als_driver); 227 228 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); 229 MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>"); 230 MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); 231 MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver"); 232 MODULE_LICENSE("GPL"); 233