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Gabriele Mazzottafeca56f2015-05-02 14:30:57 +02001/*
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
42ACPI_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 */
49static 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 },
Gabriele Mazzottafa34e6d2016-01-12 16:21:39 +010057 /* _RAW is here for backward ABI compatibility */
58 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
59 BIT(IIO_CHAN_INFO_PROCESSED),
Gabriele Mazzottafeca56f2015-05-02 14:30:57 +020060 },
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 */
Hartmut Knaack23633312015-07-18 00:56:57 +020070#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)))
Gabriele Mazzottafeca56f2015-05-02 14:30:57 +020073
74struct acpi_als {
75 struct acpi_device *device;
76 struct mutex lock;
77
Hartmut Knaack23633312015-07-18 00:56:57 +020078 s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE];
Gabriele Mazzottafeca56f2015-05-02 14:30:57 +020079};
80
81/*
82 * All types of properties the ACPI0008 block can report. The ALI, ALC, ALT
Hartmut Knaack23633312015-07-18 00:56:57 +020083 * and ALP can all be handled by acpi_als_read_value() below, while the ALR is
Gabriele Mazzottafeca56f2015-05-02 14:30:57 +020084 * 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
Hartmut Knaack23633312015-07-18 00:56:57 +020098static int acpi_als_read_value(struct acpi_als *als, char *prop, s32 *val)
Gabriele Mazzottafeca56f2015-05-02 14:30:57 +020099{
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
116static 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();
122 s32 val;
123 int ret;
124
125 mutex_lock(&als->lock);
126
Hartmut Knaack23633312015-07-18 00:56:57 +0200127 memset(buffer, 0, ACPI_ALS_EVT_BUFFER_SIZE);
Gabriele Mazzottafeca56f2015-05-02 14:30:57 +0200128
129 switch (event) {
130 case ACPI_ALS_NOTIFY_ILLUMINANCE:
Hartmut Knaack23633312015-07-18 00:56:57 +0200131 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val);
Gabriele Mazzottafeca56f2015-05-02 14:30:57 +0200132 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
145out:
146 mutex_unlock(&als->lock);
147}
148
149static 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
Gabriele Mazzottafa34e6d2016-01-12 16:21:39 +0100157 if ((mask != IIO_CHAN_INFO_PROCESSED) && (mask != IIO_CHAN_INFO_RAW))
Gabriele Mazzottafeca56f2015-05-02 14:30:57 +0200158 return -EINVAL;
159
160 /* we support only illumination (_ALI) so far. */
161 if (chan->type != IIO_LIGHT)
162 return -EINVAL;
163
Hartmut Knaack23633312015-07-18 00:56:57 +0200164 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &temp_val);
Gabriele Mazzottafeca56f2015-05-02 14:30:57 +0200165 if (ret < 0)
166 return ret;
167
168 *val = temp_val;
169
170 return IIO_VAL_INT;
171}
172
173static const struct iio_info acpi_als_info = {
174 .driver_module = THIS_MODULE,
175 .read_raw = acpi_als_read_raw,
176};
177
178static int acpi_als_add(struct acpi_device *device)
179{
180 struct acpi_als *als;
181 struct iio_dev *indio_dev;
182 struct iio_buffer *buffer;
183
184 indio_dev = devm_iio_device_alloc(&device->dev, sizeof(*als));
185 if (!indio_dev)
186 return -ENOMEM;
187
188 als = iio_priv(indio_dev);
189
190 device->driver_data = indio_dev;
191 als->device = device;
192 mutex_init(&als->lock);
193
194 indio_dev->name = ACPI_ALS_DEVICE_NAME;
195 indio_dev->dev.parent = &device->dev;
196 indio_dev->info = &acpi_als_info;
197 indio_dev->modes = INDIO_BUFFER_SOFTWARE;
198 indio_dev->channels = acpi_als_channels;
199 indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels);
200
201 buffer = devm_iio_kfifo_allocate(&device->dev);
202 if (!buffer)
203 return -ENOMEM;
204
205 iio_device_attach_buffer(indio_dev, buffer);
206
207 return devm_iio_device_register(&device->dev, indio_dev);
208}
209
210static const struct acpi_device_id acpi_als_device_ids[] = {
211 {"ACPI0008", 0},
212 {},
213};
214
215MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids);
216
217static struct acpi_driver acpi_als_driver = {
218 .name = "acpi_als",
219 .class = ACPI_ALS_CLASS,
220 .ids = acpi_als_device_ids,
221 .ops = {
222 .add = acpi_als_add,
223 .notify = acpi_als_notify,
224 },
225};
226
227module_acpi_driver(acpi_als_driver);
228
229MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
230MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>");
231MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
232MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver");
233MODULE_LICENSE("GPL");