1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * cros_ec_baro - Driver for barometer sensor behind 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/slab.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
23 /*
24 * One channel for pressure, the other for timestamp.
25 */
26 #define CROS_EC_BARO_MAX_CHANNELS (1 + 1)
27
28 /* State data for ec_sensors iio driver. */
29 struct cros_ec_baro_state {
30 /* Shared by all sensors */
31 struct cros_ec_sensors_core_state core;
32
33 struct iio_chan_spec channels[CROS_EC_BARO_MAX_CHANNELS];
34 };
35
cros_ec_baro_read(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)36 static int cros_ec_baro_read(struct iio_dev *indio_dev,
37 struct iio_chan_spec const *chan,
38 int *val, int *val2, long mask)
39 {
40 struct cros_ec_baro_state *st = iio_priv(indio_dev);
41 u16 data = 0;
42 int ret;
43 int idx = chan->scan_index;
44
45 mutex_lock(&st->core.cmd_lock);
46
47 switch (mask) {
48 case IIO_CHAN_INFO_RAW:
49 ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
50 (s16 *)&data);
51 if (ret)
52 break;
53
54 *val = data;
55 ret = IIO_VAL_INT;
56 break;
57 case IIO_CHAN_INFO_SCALE:
58 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
59 st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;
60
61 ret = cros_ec_motion_send_host_cmd(&st->core, 0);
62 if (ret)
63 break;
64
65 *val = st->core.resp->sensor_range.ret;
66
67 /* scale * in_pressure_raw --> kPa */
68 *val2 = 10 << CROS_EC_SENSOR_BITS;
69 ret = IIO_VAL_FRACTIONAL;
70 break;
71 default:
72 ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
73 mask);
74 break;
75 }
76
77 mutex_unlock(&st->core.cmd_lock);
78
79 return ret;
80 }
81
cros_ec_baro_write(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)82 static int cros_ec_baro_write(struct iio_dev *indio_dev,
83 struct iio_chan_spec const *chan,
84 int val, int val2, long mask)
85 {
86 struct cros_ec_baro_state *st = iio_priv(indio_dev);
87 int ret = 0;
88
89 mutex_lock(&st->core.cmd_lock);
90
91 switch (mask) {
92 case IIO_CHAN_INFO_SCALE:
93 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
94 st->core.param.sensor_range.data = val;
95
96 /* Always roundup, so caller gets at least what it asks for. */
97 st->core.param.sensor_range.roundup = 1;
98
99 ret = cros_ec_motion_send_host_cmd(&st->core, 0);
100 if (ret == 0) {
101 st->core.range_updated = true;
102 st->core.curr_range = val;
103 }
104 break;
105 default:
106 ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
107 mask);
108 break;
109 }
110
111 mutex_unlock(&st->core.cmd_lock);
112
113 return ret;
114 }
115
116 static const struct iio_info cros_ec_baro_info = {
117 .read_raw = &cros_ec_baro_read,
118 .write_raw = &cros_ec_baro_write,
119 .read_avail = &cros_ec_sensors_core_read_avail,
120 };
121
cros_ec_baro_probe(struct platform_device * pdev)122 static int cros_ec_baro_probe(struct platform_device *pdev)
123 {
124 struct device *dev = &pdev->dev;
125 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
126 struct iio_dev *indio_dev;
127 struct cros_ec_baro_state *state;
128 struct iio_chan_spec *channel;
129 int ret;
130
131 if (!ec_dev || !ec_dev->ec_dev) {
132 dev_warn(dev, "No CROS EC device found.\n");
133 return -EINVAL;
134 }
135
136 indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
137 if (!indio_dev)
138 return -ENOMEM;
139
140 ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
141 cros_ec_sensors_capture,
142 cros_ec_sensors_push_data);
143 if (ret)
144 return ret;
145
146 indio_dev->info = &cros_ec_baro_info;
147 state = iio_priv(indio_dev);
148 state->core.type = state->core.resp->info.type;
149 state->core.loc = state->core.resp->info.location;
150 channel = state->channels;
151 /* Common part */
152 channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
153 channel->info_mask_shared_by_all =
154 BIT(IIO_CHAN_INFO_SCALE) |
155 BIT(IIO_CHAN_INFO_SAMP_FREQ);
156 channel->info_mask_shared_by_all_available =
157 BIT(IIO_CHAN_INFO_SAMP_FREQ);
158 channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
159 channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
160 channel->scan_type.shift = 0;
161 channel->scan_index = 0;
162 channel->ext_info = cros_ec_sensors_ext_info;
163 channel->scan_type.sign = 'u';
164
165 /* Sensor specific */
166 switch (state->core.type) {
167 case MOTIONSENSE_TYPE_BARO:
168 channel->type = IIO_PRESSURE;
169 break;
170 default:
171 dev_warn(dev, "Unknown motion sensor\n");
172 return -EINVAL;
173 }
174
175 /* Timestamp */
176 channel++;
177 channel->type = IIO_TIMESTAMP;
178 channel->channel = -1;
179 channel->scan_index = 1;
180 channel->scan_type.sign = 's';
181 channel->scan_type.realbits = 64;
182 channel->scan_type.storagebits = 64;
183
184 indio_dev->channels = state->channels;
185 indio_dev->num_channels = CROS_EC_BARO_MAX_CHANNELS;
186
187 state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
188
189 return devm_iio_device_register(dev, indio_dev);
190 }
191
192 static const struct platform_device_id cros_ec_baro_ids[] = {
193 {
194 .name = "cros-ec-baro",
195 },
196 { /* sentinel */ }
197 };
198 MODULE_DEVICE_TABLE(platform, cros_ec_baro_ids);
199
200 static struct platform_driver cros_ec_baro_platform_driver = {
201 .driver = {
202 .name = "cros-ec-baro",
203 .pm = &cros_ec_sensors_pm_ops,
204 },
205 .probe = cros_ec_baro_probe,
206 .id_table = cros_ec_baro_ids,
207 };
208 module_platform_driver(cros_ec_baro_platform_driver);
209
210 MODULE_DESCRIPTION("ChromeOS EC barometer sensor driver");
211 MODULE_LICENSE("GPL v2");
212