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 | |
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, scan_mask: 1 << idx, |
51 | data: (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: &st->core, opt_length: 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: &st->core, chan, val, val2, |
74 | mask); |
75 | break; |
76 | } |
77 | |
78 | mutex_unlock(lock: &st->core.cmd_lock); |
79 | |
80 | return ret; |
81 | } |
82 | |
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: &st->core, opt_length: 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: &st->core, chan, val, val2, |
108 | mask); |
109 | break; |
110 | } |
111 | |
112 | mutex_unlock(lock: &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 | |
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: 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(parent: dev, sizeof_priv: sizeof(*state)); |
138 | if (!indio_dev) |
139 | return -ENOMEM; |
140 | |
141 | ret = cros_ec_sensors_core_init(pdev, indio_dev, physical_device: true, |
142 | trigger_capture: 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 | push_data: 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 | |