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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
feca56ff GM |
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> | |
feca56ff GM |
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 | }, | |
fa34e6dd GM |
44 | /* _RAW is here for backward ABI compatibility */ |
45 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | | |
46 | BIT(IIO_CHAN_INFO_PROCESSED), | |
feca56ff GM |
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 | */ | |
23633314 HK |
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))) | |
feca56ff GM |
60 | |
61 | struct acpi_als { | |
62 | struct acpi_device *device; | |
63 | struct mutex lock; | |
64 | ||
23633314 | 65 | s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE]; |
feca56ff GM |
66 | }; |
67 | ||
68 | /* | |
69 | * All types of properties the ACPI0008 block can report. The ALI, ALC, ALT | |
23633314 | 70 | * and ALP can all be handled by acpi_als_read_value() below, while the ALR is |
feca56ff GM |
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 | ||
23633314 | 85 | static int acpi_als_read_value(struct acpi_als *als, char *prop, s32 *val) |
feca56ff GM |
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; | |
bc2b7dab | 108 | s64 time_ns = iio_get_time_ns(indio_dev); |
feca56ff GM |
109 | s32 val; |
110 | int ret; | |
111 | ||
112 | mutex_lock(&als->lock); | |
113 | ||
23633314 | 114 | memset(buffer, 0, ACPI_ALS_EVT_BUFFER_SIZE); |
feca56ff GM |
115 | |
116 | switch (event) { | |
117 | case ACPI_ALS_NOTIFY_ILLUMINANCE: | |
23633314 | 118 | ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val); |
feca56ff GM |
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 | ||
fa34e6dd | 144 | if ((mask != IIO_CHAN_INFO_PROCESSED) && (mask != IIO_CHAN_INFO_RAW)) |
feca56ff GM |
145 | return -EINVAL; |
146 | ||
147 | /* we support only illumination (_ALI) so far. */ | |
148 | if (chan->type != IIO_LIGHT) | |
149 | return -EINVAL; | |
150 | ||
23633314 | 151 | ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &temp_val); |
feca56ff GM |
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 = { | |
feca56ff GM |
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->dev.parent = &device->dev; | |
182 | indio_dev->info = &acpi_als_info; | |
183 | indio_dev->modes = INDIO_BUFFER_SOFTWARE; | |
184 | indio_dev->channels = acpi_als_channels; | |
185 | indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels); | |
186 | ||
187 | buffer = devm_iio_kfifo_allocate(&device->dev); | |
188 | if (!buffer) | |
189 | return -ENOMEM; | |
190 | ||
191 | iio_device_attach_buffer(indio_dev, buffer); | |
192 | ||
193 | return devm_iio_device_register(&device->dev, indio_dev); | |
194 | } | |
195 | ||
196 | static const struct acpi_device_id acpi_als_device_ids[] = { | |
197 | {"ACPI0008", 0}, | |
198 | {}, | |
199 | }; | |
200 | ||
201 | MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids); | |
202 | ||
203 | static struct acpi_driver acpi_als_driver = { | |
204 | .name = "acpi_als", | |
205 | .class = ACPI_ALS_CLASS, | |
206 | .ids = acpi_als_device_ids, | |
207 | .ops = { | |
208 | .add = acpi_als_add, | |
209 | .notify = acpi_als_notify, | |
210 | }, | |
211 | }; | |
212 | ||
213 | module_acpi_driver(acpi_als_driver); | |
214 | ||
215 | MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); | |
216 | MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>"); | |
217 | MODULE_AUTHOR("Marek Vasut <marex@denx.de>"); | |
218 | MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver"); | |
219 | MODULE_LICENSE("GPL"); |