1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * cros_ec_light_prox - Driver for light and prox sensors behing CrosEC.
4  *
5  * Copyright (C) 2017 Google, Inc
6  */
7 
8 #include <linux/device.h>
9 #include <linux/iio/buffer.h>
10 #include <linux/iio/common/cros_ec_sensors_core.h>
11 #include <linux/iio/iio.h>
12 #include <linux/iio/kfifo_buf.h>
13 #include <linux/iio/trigger.h>
14 #include <linux/iio/triggered_buffer.h>
15 #include <linux/iio/trigger_consumer.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/platform_data/cros_ec_commands.h>
19 #include <linux/platform_data/cros_ec_proto.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 
23 /*
24  * We only represent one entry for light or proximity. EC is merging different
25  * light sensors to return the what the eye would see. For proximity, we
26  * currently support only one light source.
27  */
28 #define CROS_EC_LIGHT_PROX_MAX_CHANNELS (1 + 1)
29 
30 /* State data for ec_sensors iio driver. */
31 struct cros_ec_light_prox_state {
32 	/* Shared by all sensors */
33 	struct cros_ec_sensors_core_state core;
34 
35 	struct iio_chan_spec channels[CROS_EC_LIGHT_PROX_MAX_CHANNELS];
36 };
37 
38 static int cros_ec_light_prox_read(struct iio_dev *indio_dev,
39 				   struct iio_chan_spec const *chan,
40 				   int *val, int *val2, long mask)
41 {
42 	struct cros_ec_light_prox_state *st = iio_priv(indio_dev);
43 	u16 data = 0;
44 	s64 val64;
45 	int ret;
46 	int idx = chan->scan_index;
47 
48 	mutex_lock(&st->core.cmd_lock);
49 
50 	switch (mask) {
51 	case IIO_CHAN_INFO_RAW:
52 		if (chan->type == IIO_PROXIMITY) {
53 			ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
54 						     (s16 *)&data);
55 			if (ret)
56 				break;
57 			*val = data;
58 			ret = IIO_VAL_INT;
59 		} else {
60 			ret = -EINVAL;
61 		}
62 		break;
63 	case IIO_CHAN_INFO_PROCESSED:
64 		if (chan->type == IIO_LIGHT) {
65 			ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
66 						     (s16 *)&data);
67 			if (ret)
68 				break;
69 			/*
70 			 * The data coming from the light sensor is
71 			 * pre-processed and represents the ambient light
72 			 * illuminance reading expressed in lux.
73 			 */
74 			*val = data;
75 			ret = IIO_VAL_INT;
76 		} else {
77 			ret = -EINVAL;
78 		}
79 		break;
80 	case IIO_CHAN_INFO_CALIBBIAS:
81 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
82 		st->core.param.sensor_offset.flags = 0;
83 
84 		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
85 		if (ret)
86 			break;
87 
88 		/* Save values */
89 		st->core.calib[0].offset =
90 			st->core.resp->sensor_offset.offset[0];
91 
92 		*val = st->core.calib[idx].offset;
93 		ret = IIO_VAL_INT;
94 		break;
95 	case IIO_CHAN_INFO_CALIBSCALE:
96 		/*
97 		 * RANGE is used for calibration
98 		 * scale is a number x.y, where x is coded on 16 bits,
99 		 * y coded on 16 bits, between 0 and 9999.
100 		 */
101 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
102 		st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;
103 
104 		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
105 		if (ret)
106 			break;
107 
108 		val64 = st->core.resp->sensor_range.ret;
109 		*val = val64 >> 16;
110 		*val2 = (val64 & 0xffff) * 100;
111 		ret = IIO_VAL_INT_PLUS_MICRO;
112 		break;
113 	default:
114 		ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
115 						mask);
116 		break;
117 	}
118 
119 	mutex_unlock(&st->core.cmd_lock);
120 
121 	return ret;
122 }
123 
124 static int cros_ec_light_prox_write(struct iio_dev *indio_dev,
125 			       struct iio_chan_spec const *chan,
126 			       int val, int val2, long mask)
127 {
128 	struct cros_ec_light_prox_state *st = iio_priv(indio_dev);
129 	int ret;
130 	int idx = chan->scan_index;
131 
132 	mutex_lock(&st->core.cmd_lock);
133 
134 	switch (mask) {
135 	case IIO_CHAN_INFO_CALIBBIAS:
136 		st->core.calib[idx].offset = val;
137 		/* Send to EC for each axis, even if not complete */
138 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
139 		st->core.param.sensor_offset.flags = MOTION_SENSE_SET_OFFSET;
140 		st->core.param.sensor_offset.offset[0] =
141 			st->core.calib[0].offset;
142 		st->core.param.sensor_offset.temp =
143 					EC_MOTION_SENSE_INVALID_CALIB_TEMP;
144 		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
145 		break;
146 	case IIO_CHAN_INFO_CALIBSCALE:
147 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
148 		st->core.curr_range = (val << 16) | (val2 / 100);
149 		st->core.param.sensor_range.data = st->core.curr_range;
150 		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
151 		if (ret == 0)
152 			st->core.range_updated = true;
153 		break;
154 	default:
155 		ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
156 						 mask);
157 		break;
158 	}
159 
160 	mutex_unlock(&st->core.cmd_lock);
161 
162 	return ret;
163 }
164 
165 static const struct iio_info cros_ec_light_prox_info = {
166 	.read_raw = &cros_ec_light_prox_read,
167 	.write_raw = &cros_ec_light_prox_write,
168 	.read_avail = &cros_ec_sensors_core_read_avail,
169 };
170 
171 static int cros_ec_light_prox_probe(struct platform_device *pdev)
172 {
173 	struct device *dev = &pdev->dev;
174 	struct iio_dev *indio_dev;
175 	struct cros_ec_light_prox_state *state;
176 	struct iio_chan_spec *channel;
177 	int ret;
178 
179 	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
180 	if (!indio_dev)
181 		return -ENOMEM;
182 
183 	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
184 					cros_ec_sensors_capture,
185 					cros_ec_sensors_push_data,
186 					true);
187 	if (ret)
188 		return ret;
189 
190 	indio_dev->info = &cros_ec_light_prox_info;
191 	state = iio_priv(indio_dev);
192 	state->core.type = state->core.resp->info.type;
193 	state->core.loc = state->core.resp->info.location;
194 	channel = state->channels;
195 
196 	/* Common part */
197 	channel->info_mask_shared_by_all =
198 		BIT(IIO_CHAN_INFO_SAMP_FREQ);
199 	channel->info_mask_shared_by_all_available =
200 		BIT(IIO_CHAN_INFO_SAMP_FREQ);
201 	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
202 	channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
203 	channel->scan_type.shift = 0;
204 	channel->scan_index = 0;
205 	channel->ext_info = cros_ec_sensors_ext_info;
206 	channel->scan_type.sign = 'u';
207 
208 	/* Sensor specific */
209 	switch (state->core.type) {
210 	case MOTIONSENSE_TYPE_LIGHT:
211 		channel->type = IIO_LIGHT;
212 		channel->info_mask_separate =
213 			BIT(IIO_CHAN_INFO_PROCESSED) |
214 			BIT(IIO_CHAN_INFO_CALIBBIAS) |
215 			BIT(IIO_CHAN_INFO_CALIBSCALE);
216 		break;
217 	case MOTIONSENSE_TYPE_PROX:
218 		channel->type = IIO_PROXIMITY;
219 		channel->info_mask_separate =
220 			BIT(IIO_CHAN_INFO_RAW) |
221 			BIT(IIO_CHAN_INFO_CALIBBIAS) |
222 			BIT(IIO_CHAN_INFO_CALIBSCALE);
223 		break;
224 	default:
225 		dev_warn(dev, "Unknown motion sensor\n");
226 		return -EINVAL;
227 	}
228 
229 	/* Timestamp */
230 	channel++;
231 	channel->type = IIO_TIMESTAMP;
232 	channel->channel = -1;
233 	channel->scan_index = 1;
234 	channel->scan_type.sign = 's';
235 	channel->scan_type.realbits = 64;
236 	channel->scan_type.storagebits = 64;
237 
238 	indio_dev->channels = state->channels;
239 
240 	indio_dev->num_channels = CROS_EC_LIGHT_PROX_MAX_CHANNELS;
241 
242 	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
243 
244 	return devm_iio_device_register(dev, indio_dev);
245 }
246 
247 static const struct platform_device_id cros_ec_light_prox_ids[] = {
248 	{
249 		.name = "cros-ec-prox",
250 	},
251 	{
252 		.name = "cros-ec-light",
253 	},
254 	{ /* sentinel */ }
255 };
256 MODULE_DEVICE_TABLE(platform, cros_ec_light_prox_ids);
257 
258 static struct platform_driver cros_ec_light_prox_platform_driver = {
259 	.driver = {
260 		.name	= "cros-ec-light-prox",
261 		.pm	= &cros_ec_sensors_pm_ops,
262 	},
263 	.probe		= cros_ec_light_prox_probe,
264 	.id_table	= cros_ec_light_prox_ids,
265 };
266 module_platform_driver(cros_ec_light_prox_platform_driver);
267 
268 MODULE_DESCRIPTION("ChromeOS EC light/proximity sensors driver");
269 MODULE_LICENSE("GPL v2");
270