1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Driver for cros-ec proximity sensor exposed through MKBP switch
4 *
5 * Copyright 2021 Google LLC.
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/mutex.h>
11 #include <linux/notifier.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15 #include <linux/types.h>
16
17 #include <linux/platform_data/cros_ec_commands.h>
18 #include <linux/platform_data/cros_ec_proto.h>
19
20 #include <linux/iio/events.h>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23
24 #include <asm/unaligned.h>
25
26 struct cros_ec_mkbp_proximity_data {
27 struct cros_ec_device *ec;
28 struct iio_dev *indio_dev;
29 struct mutex lock;
30 struct notifier_block notifier;
31 int last_proximity;
32 bool enabled;
33 };
34
35 static const struct iio_event_spec cros_ec_mkbp_proximity_events[] = {
36 {
37 .type = IIO_EV_TYPE_THRESH,
38 .dir = IIO_EV_DIR_EITHER,
39 .mask_separate = BIT(IIO_EV_INFO_ENABLE),
40 },
41 };
42
43 static const struct iio_chan_spec cros_ec_mkbp_proximity_chan_spec[] = {
44 {
45 .type = IIO_PROXIMITY,
46 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
47 .event_spec = cros_ec_mkbp_proximity_events,
48 .num_event_specs = ARRAY_SIZE(cros_ec_mkbp_proximity_events),
49 },
50 };
51
cros_ec_mkbp_proximity_parse_state(const void * data)52 static int cros_ec_mkbp_proximity_parse_state(const void *data)
53 {
54 u32 switches = get_unaligned_le32(data);
55
56 return !!(switches & BIT(EC_MKBP_FRONT_PROXIMITY));
57 }
58
cros_ec_mkbp_proximity_query(struct cros_ec_device * ec_dev,int * state)59 static int cros_ec_mkbp_proximity_query(struct cros_ec_device *ec_dev,
60 int *state)
61 {
62 struct {
63 struct cros_ec_command msg;
64 union {
65 struct ec_params_mkbp_info params;
66 u32 switches;
67 };
68 } __packed buf = { };
69 struct ec_params_mkbp_info *params = &buf.params;
70 struct cros_ec_command *msg = &buf.msg;
71 u32 *switches = &buf.switches;
72 size_t insize = sizeof(*switches);
73 int ret;
74
75 msg->command = EC_CMD_MKBP_INFO;
76 msg->version = 1;
77 msg->outsize = sizeof(*params);
78 msg->insize = insize;
79
80 params->info_type = EC_MKBP_INFO_CURRENT;
81 params->event_type = EC_MKBP_EVENT_SWITCH;
82
83 ret = cros_ec_cmd_xfer_status(ec_dev, msg);
84 if (ret < 0)
85 return ret;
86
87 if (ret != insize) {
88 dev_warn(ec_dev->dev, "wrong result size: %d != %zu\n", ret,
89 insize);
90 return -EPROTO;
91 }
92
93 *state = cros_ec_mkbp_proximity_parse_state(switches);
94 return IIO_VAL_INT;
95 }
96
cros_ec_mkbp_proximity_push_event(struct cros_ec_mkbp_proximity_data * data,int state)97 static void cros_ec_mkbp_proximity_push_event(struct cros_ec_mkbp_proximity_data *data, int state)
98 {
99 s64 timestamp;
100 u64 ev;
101 int dir;
102 struct iio_dev *indio_dev = data->indio_dev;
103 struct cros_ec_device *ec = data->ec;
104
105 mutex_lock(&data->lock);
106 if (state != data->last_proximity) {
107 if (data->enabled) {
108 timestamp = ktime_to_ns(ec->last_event_time);
109 if (iio_device_get_clock(indio_dev) != CLOCK_BOOTTIME)
110 timestamp = iio_get_time_ns(indio_dev);
111
112 dir = state ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
113 ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
114 IIO_EV_TYPE_THRESH, dir);
115 iio_push_event(indio_dev, ev, timestamp);
116 }
117 data->last_proximity = state;
118 }
119 mutex_unlock(&data->lock);
120 }
121
cros_ec_mkbp_proximity_notify(struct notifier_block * nb,unsigned long queued_during_suspend,void * _ec)122 static int cros_ec_mkbp_proximity_notify(struct notifier_block *nb,
123 unsigned long queued_during_suspend,
124 void *_ec)
125 {
126 struct cros_ec_mkbp_proximity_data *data;
127 struct cros_ec_device *ec = _ec;
128 u8 event_type = ec->event_data.event_type & EC_MKBP_EVENT_TYPE_MASK;
129 void *switches;
130 int state;
131
132 if (event_type == EC_MKBP_EVENT_SWITCH) {
133 data = container_of(nb, struct cros_ec_mkbp_proximity_data,
134 notifier);
135
136 switches = &ec->event_data.data.switches;
137 state = cros_ec_mkbp_proximity_parse_state(switches);
138 cros_ec_mkbp_proximity_push_event(data, state);
139 }
140
141 return NOTIFY_OK;
142 }
143
cros_ec_mkbp_proximity_read_raw(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,int * val,int * val2,long mask)144 static int cros_ec_mkbp_proximity_read_raw(struct iio_dev *indio_dev,
145 const struct iio_chan_spec *chan, int *val,
146 int *val2, long mask)
147 {
148 struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
149 struct cros_ec_device *ec = data->ec;
150
151 if (chan->type == IIO_PROXIMITY && mask == IIO_CHAN_INFO_RAW)
152 return cros_ec_mkbp_proximity_query(ec, val);
153
154 return -EINVAL;
155 }
156
cros_ec_mkbp_proximity_read_event_config(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir)157 static int cros_ec_mkbp_proximity_read_event_config(struct iio_dev *indio_dev,
158 const struct iio_chan_spec *chan,
159 enum iio_event_type type,
160 enum iio_event_direction dir)
161 {
162 struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
163
164 return data->enabled;
165 }
166
cros_ec_mkbp_proximity_write_event_config(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir,int state)167 static int cros_ec_mkbp_proximity_write_event_config(struct iio_dev *indio_dev,
168 const struct iio_chan_spec *chan,
169 enum iio_event_type type,
170 enum iio_event_direction dir, int state)
171 {
172 struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
173
174 mutex_lock(&data->lock);
175 data->enabled = state;
176 mutex_unlock(&data->lock);
177
178 return 0;
179 }
180
181 static const struct iio_info cros_ec_mkbp_proximity_info = {
182 .read_raw = cros_ec_mkbp_proximity_read_raw,
183 .read_event_config = cros_ec_mkbp_proximity_read_event_config,
184 .write_event_config = cros_ec_mkbp_proximity_write_event_config,
185 };
186
cros_ec_mkbp_proximity_resume(struct device * dev)187 static int cros_ec_mkbp_proximity_resume(struct device *dev)
188 {
189 struct cros_ec_mkbp_proximity_data *data = dev_get_drvdata(dev);
190 struct cros_ec_device *ec = data->ec;
191 int ret, state;
192
193 ret = cros_ec_mkbp_proximity_query(ec, &state);
194 if (ret < 0) {
195 dev_warn(dev, "failed to fetch proximity state on resume: %d\n",
196 ret);
197 } else {
198 cros_ec_mkbp_proximity_push_event(data, state);
199 }
200
201 return 0;
202 }
203
204 static DEFINE_SIMPLE_DEV_PM_OPS(cros_ec_mkbp_proximity_pm_ops, NULL,
205 cros_ec_mkbp_proximity_resume);
206
cros_ec_mkbp_proximity_probe(struct platform_device * pdev)207 static int cros_ec_mkbp_proximity_probe(struct platform_device *pdev)
208 {
209 struct device *dev = &pdev->dev;
210 struct cros_ec_device *ec = dev_get_drvdata(dev->parent);
211 struct iio_dev *indio_dev;
212 struct cros_ec_mkbp_proximity_data *data;
213 int ret;
214
215 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
216 if (!indio_dev)
217 return -ENOMEM;
218
219 data = iio_priv(indio_dev);
220 data->ec = ec;
221 data->indio_dev = indio_dev;
222 data->last_proximity = -1; /* Unknown to start */
223 mutex_init(&data->lock);
224 platform_set_drvdata(pdev, data);
225
226 indio_dev->name = dev->driver->name;
227 indio_dev->info = &cros_ec_mkbp_proximity_info;
228 indio_dev->modes = INDIO_DIRECT_MODE;
229 indio_dev->channels = cros_ec_mkbp_proximity_chan_spec;
230 indio_dev->num_channels = ARRAY_SIZE(cros_ec_mkbp_proximity_chan_spec);
231
232 ret = devm_iio_device_register(dev, indio_dev);
233 if (ret)
234 return ret;
235
236 data->notifier.notifier_call = cros_ec_mkbp_proximity_notify;
237 blocking_notifier_chain_register(&ec->event_notifier, &data->notifier);
238
239 return 0;
240 }
241
cros_ec_mkbp_proximity_remove(struct platform_device * pdev)242 static int cros_ec_mkbp_proximity_remove(struct platform_device *pdev)
243 {
244 struct cros_ec_mkbp_proximity_data *data = platform_get_drvdata(pdev);
245 struct cros_ec_device *ec = data->ec;
246
247 blocking_notifier_chain_unregister(&ec->event_notifier,
248 &data->notifier);
249
250 return 0;
251 }
252
253 static const struct of_device_id cros_ec_mkbp_proximity_of_match[] = {
254 { .compatible = "google,cros-ec-mkbp-proximity" },
255 {}
256 };
257 MODULE_DEVICE_TABLE(of, cros_ec_mkbp_proximity_of_match);
258
259 static struct platform_driver cros_ec_mkbp_proximity_driver = {
260 .driver = {
261 .name = "cros-ec-mkbp-proximity",
262 .of_match_table = cros_ec_mkbp_proximity_of_match,
263 .pm = pm_sleep_ptr(&cros_ec_mkbp_proximity_pm_ops),
264 },
265 .probe = cros_ec_mkbp_proximity_probe,
266 .remove = cros_ec_mkbp_proximity_remove,
267 };
268 module_platform_driver(cros_ec_mkbp_proximity_driver);
269
270 MODULE_LICENSE("GPL v2");
271 MODULE_DESCRIPTION("ChromeOS EC MKBP proximity sensor driver");
272