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/mod_devicetable.h>
24  #include <linux/module.h>
25  #include <linux/platform_data/cros_ec_commands.h>
26  #include <linux/platform_device.h>
27  #include <linux/slab.h>
28  
29  #define DRV_NAME "cros-ec-lid-angle"
30  
31  /*
32   * One channel for the lid angle, the other for timestamp.
33   */
34  static const struct iio_chan_spec cros_ec_lid_angle_channels[] = {
35  	{
36  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
37  		.scan_type.realbits = CROS_EC_SENSOR_BITS,
38  		.scan_type.storagebits = CROS_EC_SENSOR_BITS,
39  		.scan_type.sign = 'u',
40  		.type = IIO_ANGL
41  	},
42  	IIO_CHAN_SOFT_TIMESTAMP(1)
43  };
44  
45  /* State data for ec_sensors iio driver. */
46  struct cros_ec_lid_angle_state {
47  	/* Shared by all sensors */
48  	struct cros_ec_sensors_core_state core;
49  };
50  
cros_ec_sensors_read_lid_angle(struct iio_dev * indio_dev,unsigned long scan_mask,s16 * data)51  static int cros_ec_sensors_read_lid_angle(struct iio_dev *indio_dev,
52  					  unsigned long scan_mask, s16 *data)
53  {
54  	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
55  	int ret;
56  
57  	st->param.cmd = MOTIONSENSE_CMD_LID_ANGLE;
58  	ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->lid_angle));
59  	if (ret) {
60  		dev_warn(&indio_dev->dev, "Unable to read lid angle\n");
61  		return ret;
62  	}
63  
64  	*data = st->resp->lid_angle.value;
65  	return 0;
66  }
67  
cros_ec_lid_angle_read(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)68  static int cros_ec_lid_angle_read(struct iio_dev *indio_dev,
69  				    struct iio_chan_spec const *chan,
70  				    int *val, int *val2, long mask)
71  {
72  	struct cros_ec_lid_angle_state *st = iio_priv(indio_dev);
73  	s16 data;
74  	int ret;
75  
76  	mutex_lock(&st->core.cmd_lock);
77  	ret = cros_ec_sensors_read_lid_angle(indio_dev, 1, &data);
78  	if (ret == 0) {
79  		*val = data;
80  		ret = IIO_VAL_INT;
81  	}
82  	mutex_unlock(&st->core.cmd_lock);
83  	return ret;
84  }
85  
86  static const struct iio_info cros_ec_lid_angle_info = {
87  	.read_raw = &cros_ec_lid_angle_read,
88  };
89  
cros_ec_lid_angle_probe(struct platform_device * pdev)90  static int cros_ec_lid_angle_probe(struct platform_device *pdev)
91  {
92  	struct device *dev = &pdev->dev;
93  	struct iio_dev *indio_dev;
94  	struct cros_ec_lid_angle_state *state;
95  	int ret;
96  
97  	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
98  	if (!indio_dev)
99  		return -ENOMEM;
100  
101  	ret = cros_ec_sensors_core_init(pdev, indio_dev, false, NULL);
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 cros_ec_sensors_core_register(dev, indio_dev, NULL);
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