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 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 58 }, 59 }; 60 61 /* 62 * The event buffer contains timestamp and all the data from 63 * the ACPI0008 block. There are multiple, but so far we only 64 * support _ALI (illuminance). Once someone adds new channels 65 * to acpi_als_channels[], the evt_buffer below will grow 66 * automatically. 67 */ 68 #define EVT_NR_SOURCES ARRAY_SIZE(acpi_als_channels) 69 #define EVT_BUFFER_SIZE \ 70 (sizeof(s64) + (EVT_NR_SOURCES * sizeof(s32))) 71 72 struct acpi_als { 73 struct acpi_device *device; 74 struct mutex lock; 75 76 s32 evt_buffer[EVT_BUFFER_SIZE]; 77 }; 78 79 /* 80 * All types of properties the ACPI0008 block can report. The ALI, ALC, ALT 81 * and ALP can all be handled by als_read_value() below, while the ALR is 82 * special. 83 * 84 * The _ALR property returns tables that can be used to fine-tune the values 85 * reported by the other props based on the particular hardware type and it's 86 * location (it contains tables for "rainy", "bright inhouse lighting" etc.). 87 * 88 * So far, we support only ALI (illuminance). 89 */ 90 #define ACPI_ALS_ILLUMINANCE "_ALI" 91 #define ACPI_ALS_CHROMATICITY "_ALC" 92 #define ACPI_ALS_COLOR_TEMP "_ALT" 93 #define ACPI_ALS_POLLING "_ALP" 94 #define ACPI_ALS_TABLES "_ALR" 95 96 static int als_read_value(struct acpi_als *als, char *prop, s32 *val) 97 { 98 unsigned long long temp_val; 99 acpi_status status; 100 101 status = acpi_evaluate_integer(als->device->handle, prop, NULL, 102 &temp_val); 103 104 if (ACPI_FAILURE(status)) { 105 ACPI_EXCEPTION((AE_INFO, status, "Error reading ALS %s", prop)); 106 return -EIO; 107 } 108 109 *val = temp_val; 110 111 return 0; 112 } 113 114 static void acpi_als_notify(struct acpi_device *device, u32 event) 115 { 116 struct iio_dev *indio_dev = acpi_driver_data(device); 117 struct acpi_als *als = iio_priv(indio_dev); 118 s32 *buffer = als->evt_buffer; 119 s64 time_ns = iio_get_time_ns(); 120 s32 val; 121 int ret; 122 123 mutex_lock(&als->lock); 124 125 memset(buffer, 0, EVT_BUFFER_SIZE); 126 127 switch (event) { 128 case ACPI_ALS_NOTIFY_ILLUMINANCE: 129 ret = als_read_value(als, ACPI_ALS_ILLUMINANCE, &val); 130 if (ret < 0) 131 goto out; 132 *buffer++ = val; 133 break; 134 default: 135 /* Unhandled event */ 136 dev_dbg(&device->dev, "Unhandled ACPI ALS event (%08x)!\n", 137 event); 138 goto out; 139 } 140 141 iio_push_to_buffers_with_timestamp(indio_dev, als->evt_buffer, time_ns); 142 143 out: 144 mutex_unlock(&als->lock); 145 } 146 147 static int acpi_als_read_raw(struct iio_dev *indio_dev, 148 struct iio_chan_spec const *chan, int *val, 149 int *val2, long mask) 150 { 151 struct acpi_als *als = iio_priv(indio_dev); 152 s32 temp_val; 153 int ret; 154 155 if (mask != IIO_CHAN_INFO_RAW) 156 return -EINVAL; 157 158 /* we support only illumination (_ALI) so far. */ 159 if (chan->type != IIO_LIGHT) 160 return -EINVAL; 161 162 ret = als_read_value(als, ACPI_ALS_ILLUMINANCE, &temp_val); 163 if (ret < 0) 164 return ret; 165 166 *val = temp_val; 167 168 return IIO_VAL_INT; 169 } 170 171 static const struct iio_info acpi_als_info = { 172 .driver_module = THIS_MODULE, 173 .read_raw = acpi_als_read_raw, 174 }; 175 176 static int acpi_als_add(struct acpi_device *device) 177 { 178 struct acpi_als *als; 179 struct iio_dev *indio_dev; 180 struct iio_buffer *buffer; 181 182 indio_dev = devm_iio_device_alloc(&device->dev, sizeof(*als)); 183 if (!indio_dev) 184 return -ENOMEM; 185 186 als = iio_priv(indio_dev); 187 188 device->driver_data = indio_dev; 189 als->device = device; 190 mutex_init(&als->lock); 191 192 indio_dev->name = ACPI_ALS_DEVICE_NAME; 193 indio_dev->dev.parent = &device->dev; 194 indio_dev->info = &acpi_als_info; 195 indio_dev->modes = INDIO_BUFFER_SOFTWARE; 196 indio_dev->channels = acpi_als_channels; 197 indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels); 198 199 buffer = devm_iio_kfifo_allocate(&device->dev); 200 if (!buffer) 201 return -ENOMEM; 202 203 iio_device_attach_buffer(indio_dev, buffer); 204 205 return devm_iio_device_register(&device->dev, indio_dev); 206 } 207 208 static const struct acpi_device_id acpi_als_device_ids[] = { 209 {"ACPI0008", 0}, 210 {}, 211 }; 212 213 MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids); 214 215 static struct acpi_driver acpi_als_driver = { 216 .name = "acpi_als", 217 .class = ACPI_ALS_CLASS, 218 .ids = acpi_als_device_ids, 219 .ops = { 220 .add = acpi_als_add, 221 .notify = acpi_als_notify, 222 }, 223 }; 224 225 module_acpi_driver(acpi_als_driver); 226 227 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); 228 MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>"); 229 MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); 230 MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver"); 231 MODULE_LICENSE("GPL"); 232