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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
46
47
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 },
57 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
58 },
59};
60
61
62
63
64
65
66
67
68#define ACPI_ALS_EVT_NR_SOURCES ARRAY_SIZE(acpi_als_channels)
69#define ACPI_ALS_EVT_BUFFER_SIZE \
70 (sizeof(s64) + (ACPI_ALS_EVT_NR_SOURCES * sizeof(s32)))
71
72struct acpi_als {
73 struct acpi_device *device;
74 struct mutex lock;
75
76 s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE];
77};
78
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88
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
96static int acpi_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
114static 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, ACPI_ALS_EVT_BUFFER_SIZE);
126
127 switch (event) {
128 case ACPI_ALS_NOTIFY_ILLUMINANCE:
129 ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val);
130 if (ret < 0)
131 goto out;
132 *buffer++ = val;
133 break;
134 default:
135
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
143out:
144 mutex_unlock(&als->lock);
145}
146
147static 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
159 if (chan->type != IIO_LIGHT)
160 return -EINVAL;
161
162 ret = acpi_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
171static const struct iio_info acpi_als_info = {
172 .driver_module = THIS_MODULE,
173 .read_raw = acpi_als_read_raw,
174};
175
176static 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
208static const struct acpi_device_id acpi_als_device_ids[] = {
209 {"ACPI0008", 0},
210 {},
211};
212
213MODULE_DEVICE_TABLE(acpi, acpi_als_device_ids);
214
215static 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
225module_acpi_driver(acpi_als_driver);
226
227MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
228MODULE_AUTHOR("Martin Liska <marxin.liska@gmail.com>");
229MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
230MODULE_DESCRIPTION("ACPI Ambient Light Sensor Driver");
231MODULE_LICENSE("GPL");
232
