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/mfd/cros_ec.h>
18 #include <linux/mfd/cros_ec_commands.h>
19 #include <linux/module.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 = IIO_VAL_INT;
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 			if (cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
54 						     (s16 *)&data) < 0) {
55 				ret = -EIO;
56 				break;
57 			}
58 			*val = data;
59 		} else {
60 			ret = -EINVAL;
61 		}
62 		break;
63 	case IIO_CHAN_INFO_PROCESSED:
64 		if (chan->type == IIO_LIGHT) {
65 			if (cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
66 						     (s16 *)&data) < 0) {
67 				ret = -EIO;
68 				break;
69 			}
70 			/*
71 			 * The data coming from the light sensor is
72 			 * pre-processed and represents the ambient light
73 			 * illuminance reading expressed in lux.
74 			 */
75 			*val = data;
76 			ret = IIO_VAL_INT;
77 		} else {
78 			ret = -EINVAL;
79 		}
80 		break;
81 	case IIO_CHAN_INFO_CALIBBIAS:
82 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
83 		st->core.param.sensor_offset.flags = 0;
84 
85 		if (cros_ec_motion_send_host_cmd(&st->core, 0)) {
86 			ret = -EIO;
87 			break;
88 		}
89 
90 		/* Save values */
91 		st->core.calib[0] = st->core.resp->sensor_offset.offset[0];
92 
93 		*val = st->core.calib[idx];
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 		if (cros_ec_motion_send_host_cmd(&st->core, 0)) {
105 			ret = -EIO;
106 			break;
107 		}
108 
109 		val64 = st->core.resp->sensor_range.ret;
110 		*val = val64 >> 16;
111 		*val2 = (val64 & 0xffff) * 100;
112 		ret = IIO_VAL_INT_PLUS_MICRO;
113 		break;
114 	default:
115 		ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
116 						mask);
117 		break;
118 	}
119 
120 	mutex_unlock(&st->core.cmd_lock);
121 
122 	return ret;
123 }
124 
125 static int cros_ec_light_prox_write(struct iio_dev *indio_dev,
126 			       struct iio_chan_spec const *chan,
127 			       int val, int val2, long mask)
128 {
129 	struct cros_ec_light_prox_state *st = iio_priv(indio_dev);
130 	int ret = 0;
131 	int idx = chan->scan_index;
132 
133 	mutex_lock(&st->core.cmd_lock);
134 
135 	switch (mask) {
136 	case IIO_CHAN_INFO_CALIBBIAS:
137 		st->core.calib[idx] = val;
138 		/* Send to EC for each axis, even if not complete */
139 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
140 		st->core.param.sensor_offset.flags = MOTION_SENSE_SET_OFFSET;
141 		st->core.param.sensor_offset.offset[0] = st->core.calib[0];
142 		st->core.param.sensor_offset.temp =
143 					EC_MOTION_SENSE_INVALID_CALIB_TEMP;
144 		if (cros_ec_motion_send_host_cmd(&st->core, 0))
145 			ret = -EIO;
146 		break;
147 	case IIO_CHAN_INFO_CALIBSCALE:
148 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
149 		st->core.param.sensor_range.data = (val << 16) | (val2 / 100);
150 		if (cros_ec_motion_send_host_cmd(&st->core, 0))
151 			ret = -EIO;
152 		break;
153 	default:
154 		ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
155 						 mask);
156 		break;
157 	}
158 
159 	mutex_unlock(&st->core.cmd_lock);
160 
161 	return ret;
162 }
163 
164 static const struct iio_info cros_ec_light_prox_info = {
165 	.read_raw = &cros_ec_light_prox_read,
166 	.write_raw = &cros_ec_light_prox_write,
167 };
168 
169 static int cros_ec_light_prox_probe(struct platform_device *pdev)
170 {
171 	struct device *dev = &pdev->dev;
172 	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
173 	struct iio_dev *indio_dev;
174 	struct cros_ec_light_prox_state *state;
175 	struct iio_chan_spec *channel;
176 	int ret;
177 
178 	if (!ec_dev || !ec_dev->ec_dev) {
179 		dev_warn(dev, "No CROS EC device found.\n");
180 		return -EINVAL;
181 	}
182 
183 	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
184 	if (!indio_dev)
185 		return -ENOMEM;
186 
187 	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
188 	if (ret)
189 		return ret;
190 
191 	indio_dev->info = &cros_ec_light_prox_info;
192 	state = iio_priv(indio_dev);
193 	state->core.type = state->core.resp->info.type;
194 	state->core.loc = state->core.resp->info.location;
195 	channel = state->channels;
196 
197 	/* Common part */
198 	channel->info_mask_shared_by_all =
199 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
200 		BIT(IIO_CHAN_INFO_FREQUENCY);
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 	state->core.calib[0] = 0;
209 
210 	/* Sensor specific */
211 	switch (state->core.type) {
212 	case MOTIONSENSE_TYPE_LIGHT:
213 		channel->type = IIO_LIGHT;
214 		channel->info_mask_separate =
215 			BIT(IIO_CHAN_INFO_PROCESSED) |
216 			BIT(IIO_CHAN_INFO_CALIBBIAS) |
217 			BIT(IIO_CHAN_INFO_CALIBSCALE);
218 		break;
219 	case MOTIONSENSE_TYPE_PROX:
220 		channel->type = IIO_PROXIMITY;
221 		channel->info_mask_separate =
222 			BIT(IIO_CHAN_INFO_RAW) |
223 			BIT(IIO_CHAN_INFO_CALIBBIAS) |
224 			BIT(IIO_CHAN_INFO_CALIBSCALE);
225 		break;
226 	default:
227 		dev_warn(dev, "Unknown motion sensor\n");
228 		return -EINVAL;
229 	}
230 
231 	/* Timestamp */
232 	channel++;
233 	channel->type = IIO_TIMESTAMP;
234 	channel->channel = -1;
235 	channel->scan_index = 1;
236 	channel->scan_type.sign = 's';
237 	channel->scan_type.realbits = 64;
238 	channel->scan_type.storagebits = 64;
239 
240 	indio_dev->channels = state->channels;
241 
242 	indio_dev->num_channels = CROS_EC_LIGHT_PROX_MAX_CHANNELS;
243 
244 	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
245 
246 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
247 					      cros_ec_sensors_capture, NULL);
248 	if (ret)
249 		return ret;
250 
251 	return devm_iio_device_register(dev, indio_dev);
252 }
253 
254 static const struct platform_device_id cros_ec_light_prox_ids[] = {
255 	{
256 		.name = "cros-ec-prox",
257 	},
258 	{
259 		.name = "cros-ec-light",
260 	},
261 	{ /* sentinel */ }
262 };
263 MODULE_DEVICE_TABLE(platform, cros_ec_light_prox_ids);
264 
265 static struct platform_driver cros_ec_light_prox_platform_driver = {
266 	.driver = {
267 		.name	= "cros-ec-light-prox",
268 		.pm	= &cros_ec_sensors_pm_ops,
269 	},
270 	.probe		= cros_ec_light_prox_probe,
271 	.id_table	= cros_ec_light_prox_ids,
272 };
273 module_platform_driver(cros_ec_light_prox_platform_driver);
274 
275 MODULE_DESCRIPTION("ChromeOS EC light/proximity sensors driver");
276 MODULE_LICENSE("GPL v2");
277