1 // SPDX-License-Identifier: GPL-2.0
2
3 /*
4 * cros_ec_lid_angle - Driver for CrOS EC lid angle sensor.
5 *
6 * Copyright 2018 Google, Inc
7 *
8 * This driver uses the cros-ec interface to communicate with the Chrome OS
9 * EC about counter sensors. Counters are presented through
10 * iio sysfs.
11 */
12
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/iio/buffer.h>
16 #include <linux/iio/common/cros_ec_sensors_core.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/kfifo_buf.h>
19 #include <linux/iio/trigger.h>
20 #include <linux/iio/triggered_buffer.h>
21 #include <linux/iio/trigger_consumer.h>
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/platform_data/cros_ec_commands.h>
25 #include <linux/platform_device.h>
26 #include <linux/slab.h>
27
28 #define DRV_NAME "cros-ec-lid-angle"
29
30 /*
31 * One channel for the lid angle, the other for timestamp.
32 */
33 static const struct iio_chan_spec cros_ec_lid_angle_channels[] = {
34 {
35 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
36 .scan_type.realbits = CROS_EC_SENSOR_BITS,
37 .scan_type.storagebits = CROS_EC_SENSOR_BITS,
38 .scan_type.sign = 'u',
39 .type = IIO_ANGL
40 },
41 IIO_CHAN_SOFT_TIMESTAMP(1)
42 };
43
44 /* State data for ec_sensors iio driver. */
45 struct cros_ec_lid_angle_state {
46 /* Shared by all sensors */
47 struct cros_ec_sensors_core_state core;
48 };
49
cros_ec_sensors_read_lid_angle(struct iio_dev * indio_dev,unsigned long scan_mask,s16 * data)50 static int cros_ec_sensors_read_lid_angle(struct iio_dev *indio_dev,
51 unsigned long scan_mask, s16 *data)
52 {
53 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
54 int ret;
55
56 st->param.cmd = MOTIONSENSE_CMD_LID_ANGLE;
57 ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->lid_angle));
58 if (ret) {
59 dev_warn(&indio_dev->dev, "Unable to read lid angle\n");
60 return ret;
61 }
62
63 *data = st->resp->lid_angle.value;
64 return 0;
65 }
66
cros_ec_lid_angle_read(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)67 static int cros_ec_lid_angle_read(struct iio_dev *indio_dev,
68 struct iio_chan_spec const *chan,
69 int *val, int *val2, long mask)
70 {
71 struct cros_ec_lid_angle_state *st = iio_priv(indio_dev);
72 s16 data;
73 int ret;
74
75 mutex_lock(&st->core.cmd_lock);
76 ret = cros_ec_sensors_read_lid_angle(indio_dev, 1, &data);
77 if (ret == 0) {
78 *val = data;
79 ret = IIO_VAL_INT;
80 }
81 mutex_unlock(&st->core.cmd_lock);
82 return ret;
83 }
84
85 static const struct iio_info cros_ec_lid_angle_info = {
86 .read_raw = &cros_ec_lid_angle_read,
87 };
88
cros_ec_lid_angle_probe(struct platform_device * pdev)89 static int cros_ec_lid_angle_probe(struct platform_device *pdev)
90 {
91 struct device *dev = &pdev->dev;
92 struct iio_dev *indio_dev;
93 struct cros_ec_lid_angle_state *state;
94 int ret;
95
96 indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
97 if (!indio_dev)
98 return -ENOMEM;
99
100 ret = cros_ec_sensors_core_init(pdev, indio_dev, false, NULL,
101 NULL, false);
102 if (ret)
103 return ret;
104
105 indio_dev->info = &cros_ec_lid_angle_info;
106 state = iio_priv(indio_dev);
107 indio_dev->channels = cros_ec_lid_angle_channels;
108 indio_dev->num_channels = ARRAY_SIZE(cros_ec_lid_angle_channels);
109
110 state->core.read_ec_sensors_data = cros_ec_sensors_read_lid_angle;
111
112 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
113 cros_ec_sensors_capture, NULL);
114 if (ret)
115 return ret;
116
117 return devm_iio_device_register(dev, indio_dev);
118 }
119
120 static const struct platform_device_id cros_ec_lid_angle_ids[] = {
121 {
122 .name = DRV_NAME,
123 },
124 { /* sentinel */ }
125 };
126 MODULE_DEVICE_TABLE(platform, cros_ec_lid_angle_ids);
127
128 static struct platform_driver cros_ec_lid_angle_platform_driver = {
129 .driver = {
130 .name = DRV_NAME,
131 },
132 .probe = cros_ec_lid_angle_probe,
133 .id_table = cros_ec_lid_angle_ids,
134 };
135 module_platform_driver(cros_ec_lid_angle_platform_driver);
136
137 MODULE_DESCRIPTION("ChromeOS EC driver for reporting convertible lid angle.");
138 MODULE_LICENSE("GPL v2");
139