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/module.h>
19 #include <linux/platform_data/cros_ec_commands.h>
20 #include <linux/platform_data/cros_ec_proto.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23 
24 /*
25  * We only represent one entry for light or proximity. EC is merging different
26  * light sensors to return the what the eye would see. For proximity, we
27  * currently support only one light source.
28  */
29 #define CROS_EC_LIGHT_PROX_MAX_CHANNELS (1 + 1)
30 
31 /* State data for ec_sensors iio driver. */
32 struct cros_ec_light_prox_state {
33 	/* Shared by all sensors */
34 	struct cros_ec_sensors_core_state core;
35 
36 	struct iio_chan_spec channels[CROS_EC_LIGHT_PROX_MAX_CHANNELS];
37 };
38 
39 static int cros_ec_light_prox_read(struct iio_dev *indio_dev,
40 				   struct iio_chan_spec const *chan,
41 				   int *val, int *val2, long mask)
42 {
43 	struct cros_ec_light_prox_state *st = iio_priv(indio_dev);
44 	u16 data = 0;
45 	s64 val64;
46 	int ret;
47 	int idx = chan->scan_index;
48 
49 	mutex_lock(&st->core.cmd_lock);
50 
51 	switch (mask) {
52 	case IIO_CHAN_INFO_RAW:
53 		if (chan->type == IIO_PROXIMITY) {
54 			ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
55 						     (s16 *)&data);
56 			if (ret)
57 				break;
58 			*val = data;
59 			ret = IIO_VAL_INT;
60 		} else {
61 			ret = -EINVAL;
62 		}
63 		break;
64 	case IIO_CHAN_INFO_PROCESSED:
65 		if (chan->type == IIO_LIGHT) {
66 			ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
67 						     (s16 *)&data);
68 			if (ret)
69 				break;
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 		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
86 		if (ret)
87 			break;
88 
89 		/* Save values */
90 		st->core.calib[0].offset =
91 			st->core.resp->sensor_offset.offset[0];
92 
93 		*val = st->core.calib[idx].offset;
94 		ret = IIO_VAL_INT;
95 		break;
96 	case IIO_CHAN_INFO_CALIBSCALE:
97 		/*
98 		 * RANGE is used for calibration
99 		 * scale is a number x.y, where x is coded on 16 bits,
100 		 * y coded on 16 bits, between 0 and 9999.
101 		 */
102 		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
103 		st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;
104 
105 		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
106 		if (ret)
107 			break;
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;
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].offset = 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] =
142 			st->core.calib[0].offset;
143 		st->core.param.sensor_offset.temp =
144 					EC_MOTION_SENSE_INVALID_CALIB_TEMP;
145 		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
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 		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
151 		break;
152 	default:
153 		ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
154 						 mask);
155 		break;
156 	}
157 
158 	mutex_unlock(&st->core.cmd_lock);
159 
160 	return ret;
161 }
162 
163 static const struct iio_info cros_ec_light_prox_info = {
164 	.read_raw = &cros_ec_light_prox_read,
165 	.write_raw = &cros_ec_light_prox_write,
166 	.read_avail = &cros_ec_sensors_core_read_avail,
167 };
168 
169 static int cros_ec_light_prox_probe(struct platform_device *pdev)
170 {
171 	struct device *dev = &pdev->dev;
172 	struct iio_dev *indio_dev;
173 	struct cros_ec_light_prox_state *state;
174 	struct iio_chan_spec *channel;
175 	int ret;
176 
177 	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
178 	if (!indio_dev)
179 		return -ENOMEM;
180 
181 	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
182 	if (ret)
183 		return ret;
184 
185 	indio_dev->info = &cros_ec_light_prox_info;
186 	state = iio_priv(indio_dev);
187 	state->core.type = state->core.resp->info.type;
188 	state->core.loc = state->core.resp->info.location;
189 	channel = state->channels;
190 
191 	/* Common part */
192 	channel->info_mask_shared_by_all =
193 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
194 		BIT(IIO_CHAN_INFO_FREQUENCY);
195 	channel->info_mask_shared_by_all_available =
196 		BIT(IIO_CHAN_INFO_SAMP_FREQ);
197 	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
198 	channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
199 	channel->scan_type.shift = 0;
200 	channel->scan_index = 0;
201 	channel->ext_info = cros_ec_sensors_ext_info;
202 	channel->scan_type.sign = 'u';
203 
204 	/* Sensor specific */
205 	switch (state->core.type) {
206 	case MOTIONSENSE_TYPE_LIGHT:
207 		channel->type = IIO_LIGHT;
208 		channel->info_mask_separate =
209 			BIT(IIO_CHAN_INFO_PROCESSED) |
210 			BIT(IIO_CHAN_INFO_CALIBBIAS) |
211 			BIT(IIO_CHAN_INFO_CALIBSCALE);
212 		break;
213 	case MOTIONSENSE_TYPE_PROX:
214 		channel->type = IIO_PROXIMITY;
215 		channel->info_mask_separate =
216 			BIT(IIO_CHAN_INFO_RAW) |
217 			BIT(IIO_CHAN_INFO_CALIBBIAS) |
218 			BIT(IIO_CHAN_INFO_CALIBSCALE);
219 		break;
220 	default:
221 		dev_warn(dev, "Unknown motion sensor\n");
222 		return -EINVAL;
223 	}
224 
225 	/* Timestamp */
226 	channel++;
227 	channel->type = IIO_TIMESTAMP;
228 	channel->channel = -1;
229 	channel->scan_index = 1;
230 	channel->scan_type.sign = 's';
231 	channel->scan_type.realbits = 64;
232 	channel->scan_type.storagebits = 64;
233 
234 	indio_dev->channels = state->channels;
235 
236 	indio_dev->num_channels = CROS_EC_LIGHT_PROX_MAX_CHANNELS;
237 
238 	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
239 
240 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
241 					      cros_ec_sensors_capture, NULL);
242 	if (ret)
243 		return ret;
244 
245 	return devm_iio_device_register(dev, indio_dev);
246 }
247 
248 static const struct platform_device_id cros_ec_light_prox_ids[] = {
249 	{
250 		.name = "cros-ec-prox",
251 	},
252 	{
253 		.name = "cros-ec-light",
254 	},
255 	{ /* sentinel */ }
256 };
257 MODULE_DEVICE_TABLE(platform, cros_ec_light_prox_ids);
258 
259 static struct platform_driver cros_ec_light_prox_platform_driver = {
260 	.driver = {
261 		.name	= "cros-ec-light-prox",
262 		.pm	= &cros_ec_sensors_pm_ops,
263 	},
264 	.probe		= cros_ec_light_prox_probe,
265 	.id_table	= cros_ec_light_prox_ids,
266 };
267 module_platform_driver(cros_ec_light_prox_platform_driver);
268 
269 MODULE_DESCRIPTION("ChromeOS EC light/proximity sensors driver");
270 MODULE_LICENSE("GPL v2");
271