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