xref: /linux/drivers/iio/light/cros_ec_light_prox.c (revision 9fb29c734f9e98adc1f2f3c4629fe487cb93f2dd)
1 /*
2  * cros_ec_light_prox - Driver for light and prox sensors behing CrosEC.
3  *
4  * Copyright (C) 2017 Google, Inc
5  *
6  * This software is licensed under the terms of the GNU General Public
7  * License version 2, as published by the Free Software Foundation, and
8  * may be copied, distributed, and modified under those terms.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/delay.h>
17 #include <linux/device.h>
18 #include <linux/iio/buffer.h>
19 #include <linux/iio/common/cros_ec_sensors_core.h>
20 #include <linux/iio/iio.h>
21 #include <linux/iio/kfifo_buf.h>
22 #include <linux/iio/trigger.h>
23 #include <linux/iio/triggered_buffer.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include <linux/kernel.h>
26 #include <linux/mfd/cros_ec.h>
27 #include <linux/mfd/cros_ec_commands.h>
28 #include <linux/module.h>
29 #include <linux/platform_device.h>
30 #include <linux/slab.h>
31 #include <linux/sysfs.h>
32 
33 /*
34  * We only represent one entry for light or proximity. EC is merging different
35  * light sensors to return the what the eye would see. For proximity, we
36  * currently support only one light source.
37  */
38 #define CROS_EC_LIGHT_PROX_MAX_CHANNELS (1 + 1)
39 
40 /* State data for ec_sensors iio driver. */
41 struct cros_ec_light_prox_state {
42 	/* Shared by all sensors */
43 	struct cros_ec_sensors_core_state core;
44 
45 	struct iio_chan_spec channels[CROS_EC_LIGHT_PROX_MAX_CHANNELS];
46 };
47 
48 static int cros_ec_light_prox_read(struct iio_dev *indio_dev,
49 				   struct iio_chan_spec const *chan,
50 				   int *val, int *val2, long mask)
51 {
52 	struct cros_ec_light_prox_state *st = iio_priv(indio_dev);
53 	u16 data = 0;
54 	s64 val64;
55 	int ret = IIO_VAL_INT;
56 	int idx = chan->scan_index;
57 
58 	mutex_lock(&st->core.cmd_lock);
59 
60 	switch (mask) {
61 	case IIO_CHAN_INFO_RAW:
62 		if (chan->type == IIO_PROXIMITY) {
63 			if (cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
64 						     (s16 *)&data) < 0) {
65 				ret = -EIO;
66 				break;
67 			}
68 			*val = data;
69 		} else {
70 			ret = -EINVAL;
71 		}
72 		break;
73 	case IIO_CHAN_INFO_PROCESSED:
74 		if (chan->type == IIO_LIGHT) {
75 			if (cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
76 						     (s16 *)&data) < 0) {
77 				ret = -EIO;
78 				break;
79 			}
80 			/*
81 			 * The data coming from the light sensor is
82 			 * pre-processed and represents the ambient light
83 			 * illuminance reading expressed in lux.
84 			 */
85 			*val = data;
86 			ret = IIO_VAL_INT;
87 		} else {
88 			ret = -EINVAL;
89 		}
90 		break;
91 	case IIO_CHAN_INFO_CALIBBIAS:
92 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
93 		st->core.param.sensor_offset.flags = 0;
94 
95 		if (cros_ec_motion_send_host_cmd(&st->core, 0)) {
96 			ret = -EIO;
97 			break;
98 		}
99 
100 		/* Save values */
101 		st->core.calib[0] = st->core.resp->sensor_offset.offset[0];
102 
103 		*val = st->core.calib[idx];
104 		break;
105 	case IIO_CHAN_INFO_CALIBSCALE:
106 		/*
107 		 * RANGE is used for calibration
108 		 * scale is a number x.y, where x is coded on 16 bits,
109 		 * y coded on 16 bits, between 0 and 9999.
110 		 */
111 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
112 		st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;
113 
114 		if (cros_ec_motion_send_host_cmd(&st->core, 0)) {
115 			ret = -EIO;
116 			break;
117 		}
118 
119 		val64 = st->core.resp->sensor_range.ret;
120 		*val = val64 >> 16;
121 		*val2 = (val64 & 0xffff) * 100;
122 		ret = IIO_VAL_INT_PLUS_MICRO;
123 		break;
124 	default:
125 		ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
126 						mask);
127 		break;
128 	}
129 
130 	mutex_unlock(&st->core.cmd_lock);
131 
132 	return ret;
133 }
134 
135 static int cros_ec_light_prox_write(struct iio_dev *indio_dev,
136 			       struct iio_chan_spec const *chan,
137 			       int val, int val2, long mask)
138 {
139 	struct cros_ec_light_prox_state *st = iio_priv(indio_dev);
140 	int ret = 0;
141 	int idx = chan->scan_index;
142 
143 	mutex_lock(&st->core.cmd_lock);
144 
145 	switch (mask) {
146 	case IIO_CHAN_INFO_CALIBBIAS:
147 		st->core.calib[idx] = val;
148 		/* Send to EC for each axis, even if not complete */
149 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
150 		st->core.param.sensor_offset.flags = MOTION_SENSE_SET_OFFSET;
151 		st->core.param.sensor_offset.offset[0] = st->core.calib[0];
152 		st->core.param.sensor_offset.temp =
153 					EC_MOTION_SENSE_INVALID_CALIB_TEMP;
154 		if (cros_ec_motion_send_host_cmd(&st->core, 0))
155 			ret = -EIO;
156 		break;
157 	case IIO_CHAN_INFO_CALIBSCALE:
158 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
159 		st->core.param.sensor_range.data = (val << 16) | (val2 / 100);
160 		if (cros_ec_motion_send_host_cmd(&st->core, 0))
161 			ret = -EIO;
162 		break;
163 	default:
164 		ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
165 						 mask);
166 		break;
167 	}
168 
169 	mutex_unlock(&st->core.cmd_lock);
170 
171 	return ret;
172 }
173 
174 static const struct iio_info cros_ec_light_prox_info = {
175 	.read_raw = &cros_ec_light_prox_read,
176 	.write_raw = &cros_ec_light_prox_write,
177 };
178 
179 static int cros_ec_light_prox_probe(struct platform_device *pdev)
180 {
181 	struct device *dev = &pdev->dev;
182 	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
183 	struct iio_dev *indio_dev;
184 	struct cros_ec_light_prox_state *state;
185 	struct iio_chan_spec *channel;
186 	int ret;
187 
188 	if (!ec_dev || !ec_dev->ec_dev) {
189 		dev_warn(dev, "No CROS EC device found.\n");
190 		return -EINVAL;
191 	}
192 
193 	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
194 	if (!indio_dev)
195 		return -ENOMEM;
196 
197 	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
198 	if (ret)
199 		return ret;
200 
201 	indio_dev->info = &cros_ec_light_prox_info;
202 	state = iio_priv(indio_dev);
203 	state->core.type = state->core.resp->info.type;
204 	state->core.loc = state->core.resp->info.location;
205 	channel = state->channels;
206 
207 	/* Common part */
208 	channel->info_mask_shared_by_all =
209 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
210 		BIT(IIO_CHAN_INFO_FREQUENCY);
211 	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
212 	channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
213 	channel->scan_type.shift = 0;
214 	channel->scan_index = 0;
215 	channel->ext_info = cros_ec_sensors_ext_info;
216 	channel->scan_type.sign = 'u';
217 
218 	state->core.calib[0] = 0;
219 
220 	/* Sensor specific */
221 	switch (state->core.type) {
222 	case MOTIONSENSE_TYPE_LIGHT:
223 		channel->type = IIO_LIGHT;
224 		channel->info_mask_separate =
225 			BIT(IIO_CHAN_INFO_PROCESSED) |
226 			BIT(IIO_CHAN_INFO_CALIBBIAS) |
227 			BIT(IIO_CHAN_INFO_CALIBSCALE);
228 		break;
229 	case MOTIONSENSE_TYPE_PROX:
230 		channel->type = IIO_PROXIMITY;
231 		channel->info_mask_separate =
232 			BIT(IIO_CHAN_INFO_RAW) |
233 			BIT(IIO_CHAN_INFO_CALIBBIAS) |
234 			BIT(IIO_CHAN_INFO_CALIBSCALE);
235 		break;
236 	default:
237 		dev_warn(dev, "Unknown motion sensor\n");
238 		return -EINVAL;
239 	}
240 
241 	/* Timestamp */
242 	channel++;
243 	channel->type = IIO_TIMESTAMP;
244 	channel->channel = -1;
245 	channel->scan_index = 1;
246 	channel->scan_type.sign = 's';
247 	channel->scan_type.realbits = 64;
248 	channel->scan_type.storagebits = 64;
249 
250 	indio_dev->channels = state->channels;
251 
252 	indio_dev->num_channels = CROS_EC_LIGHT_PROX_MAX_CHANNELS;
253 
254 	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
255 
256 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
257 					      cros_ec_sensors_capture, NULL);
258 	if (ret)
259 		return ret;
260 
261 	return devm_iio_device_register(dev, indio_dev);
262 }
263 
264 static const struct platform_device_id cros_ec_light_prox_ids[] = {
265 	{
266 		.name = "cros-ec-prox",
267 	},
268 	{
269 		.name = "cros-ec-light",
270 	},
271 	{ /* sentinel */ }
272 };
273 MODULE_DEVICE_TABLE(platform, cros_ec_light_prox_ids);
274 
275 static struct platform_driver cros_ec_light_prox_platform_driver = {
276 	.driver = {
277 		.name	= "cros-ec-light-prox",
278 		.pm	= &cros_ec_sensors_pm_ops,
279 	},
280 	.probe		= cros_ec_light_prox_probe,
281 	.id_table	= cros_ec_light_prox_ids,
282 };
283 module_platform_driver(cros_ec_light_prox_platform_driver);
284 
285 MODULE_DESCRIPTION("ChromeOS EC light/proximity sensors driver");
286 MODULE_LICENSE("GPL v2");
287