1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Sensor HUB driver that discovers sensors behind a ChromeOS Embedded
4 * Controller.
5 *
6 * Copyright 2019 Google LLC
7 */
8
9#include <linux/init.h>
10#include <linux/device.h>
11#include <linux/delay.h>
12#include <linux/mod_devicetable.h>
13#include <linux/module.h>
14#include <linux/platform_data/cros_ec_commands.h>
15#include <linux/platform_data/cros_ec_proto.h>
16#include <linux/platform_data/cros_ec_sensorhub.h>
17#include <linux/platform_device.h>
18#include <linux/slab.h>
19#include <linux/types.h>
20
21#define DRV_NAME "cros-ec-sensorhub"
22#define CROS_EC_CMD_INFO_RETRIES 50
23
24static void cros_ec_sensorhub_free_sensor(void *arg)
25{
26 struct platform_device *pdev = arg;
27
28 platform_device_unregister(pdev);
29}
30
31static int cros_ec_sensorhub_allocate_sensor(struct device *parent,
32 char *sensor_name,
33 int sensor_num)
34{
35 struct cros_ec_sensor_platform sensor_platforms = {
36 .sensor_num = sensor_num,
37 };
38 struct platform_device *pdev;
39
40 pdev = platform_device_register_data(parent, name: sensor_name,
41 PLATFORM_DEVID_AUTO,
42 data: &sensor_platforms,
43 size: sizeof(sensor_platforms));
44 if (IS_ERR(ptr: pdev))
45 return PTR_ERR(ptr: pdev);
46
47 return devm_add_action_or_reset(parent,
48 cros_ec_sensorhub_free_sensor,
49 pdev);
50}
51
52static int cros_ec_sensorhub_register(struct device *dev,
53 struct cros_ec_sensorhub *sensorhub)
54{
55 int sensor_type[MOTIONSENSE_TYPE_MAX] = { 0 };
56 struct cros_ec_command *msg = sensorhub->msg;
57 struct cros_ec_dev *ec = sensorhub->ec;
58 int ret, i, retries;
59 char *name;
60
61
62 msg->version = 1;
63 msg->insize = sizeof(struct ec_response_motion_sense);
64 msg->outsize = sizeof(struct ec_params_motion_sense);
65
66 for (i = 0; i < sensorhub->sensor_num; i++) {
67 sensorhub->params->cmd = MOTIONSENSE_CMD_INFO;
68 sensorhub->params->info.sensor_num = i;
69
70 retries = CROS_EC_CMD_INFO_RETRIES;
71 do {
72 ret = cros_ec_cmd_xfer_status(ec_dev: ec->ec_dev, msg);
73 if (ret == -EBUSY) {
74 /* The EC is still busy initializing sensors. */
75 usleep_range(min: 5000, max: 6000);
76 retries--;
77 }
78 } while (ret == -EBUSY && retries);
79
80 if (ret < 0) {
81 dev_err(dev, "no info for EC sensor %d : %d/%d\n",
82 i, ret, msg->result);
83 continue;
84 }
85 if (retries < CROS_EC_CMD_INFO_RETRIES) {
86 dev_warn(dev, "%d retries needed to bring up sensor %d\n",
87 CROS_EC_CMD_INFO_RETRIES - retries, i);
88 }
89
90 switch (sensorhub->resp->info.type) {
91 case MOTIONSENSE_TYPE_ACCEL:
92 name = "cros-ec-accel";
93 break;
94 case MOTIONSENSE_TYPE_BARO:
95 name = "cros-ec-baro";
96 break;
97 case MOTIONSENSE_TYPE_GYRO:
98 name = "cros-ec-gyro";
99 break;
100 case MOTIONSENSE_TYPE_MAG:
101 name = "cros-ec-mag";
102 break;
103 case MOTIONSENSE_TYPE_PROX:
104 name = "cros-ec-prox";
105 break;
106 case MOTIONSENSE_TYPE_LIGHT:
107 name = "cros-ec-light";
108 break;
109 case MOTIONSENSE_TYPE_ACTIVITY:
110 name = "cros-ec-activity";
111 break;
112 default:
113 dev_warn(dev, "unknown type %d\n",
114 sensorhub->resp->info.type);
115 continue;
116 }
117
118 ret = cros_ec_sensorhub_allocate_sensor(parent: dev, sensor_name: name, sensor_num: i);
119 if (ret)
120 return ret;
121
122 sensor_type[sensorhub->resp->info.type]++;
123 }
124
125 if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
126 ec->has_kb_wake_angle = true;
127
128 if (cros_ec_check_features(ec,
129 feature: EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
130 ret = cros_ec_sensorhub_allocate_sensor(parent: dev,
131 sensor_name: "cros-ec-lid-angle",
132 sensor_num: 0);
133 if (ret)
134 return ret;
135 }
136
137 return 0;
138}
139
140static int cros_ec_sensorhub_probe(struct platform_device *pdev)
141{
142 struct device *dev = &pdev->dev;
143 struct cros_ec_dev *ec = dev_get_drvdata(dev: dev->parent);
144 struct cros_ec_sensorhub *data;
145 struct cros_ec_command *msg;
146 int ret, i, sensor_num;
147
148 msg = devm_kzalloc(dev, size: sizeof(struct cros_ec_command) +
149 max((u16)sizeof(struct ec_params_motion_sense),
150 ec->ec_dev->max_response), GFP_KERNEL);
151 if (!msg)
152 return -ENOMEM;
153
154 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
155
156 data = devm_kzalloc(dev, size: sizeof(struct cros_ec_sensorhub), GFP_KERNEL);
157 if (!data)
158 return -ENOMEM;
159
160 mutex_init(&data->cmd_lock);
161
162 data->dev = dev;
163 data->ec = ec;
164 data->msg = msg;
165 data->params = (struct ec_params_motion_sense *)msg->data;
166 data->resp = (struct ec_response_motion_sense *)msg->data;
167
168 dev_set_drvdata(dev, data);
169
170 /* Check whether this EC is a sensor hub. */
171 if (cros_ec_check_features(ec, feature: EC_FEATURE_MOTION_SENSE)) {
172 sensor_num = cros_ec_get_sensor_count(ec);
173 if (sensor_num < 0) {
174 dev_err(dev,
175 "Unable to retrieve sensor information (err:%d)\n",
176 sensor_num);
177 return sensor_num;
178 }
179 if (sensor_num == 0) {
180 dev_err(dev, "Zero sensors reported.\n");
181 return -EINVAL;
182 }
183 data->sensor_num = sensor_num;
184
185 /*
186 * Prepare the ring handler before enumering the
187 * sensors.
188 */
189 if (cros_ec_check_features(ec, feature: EC_FEATURE_MOTION_SENSE_FIFO)) {
190 ret = cros_ec_sensorhub_ring_allocate(sensorhub: data);
191 if (ret)
192 return ret;
193 }
194
195 /* Enumerate the sensors.*/
196 ret = cros_ec_sensorhub_register(dev, sensorhub: data);
197 if (ret)
198 return ret;
199
200 /*
201 * When the EC does not have a FIFO, the sensors will query
202 * their data themselves via sysfs or a software trigger.
203 */
204 if (cros_ec_check_features(ec, feature: EC_FEATURE_MOTION_SENSE_FIFO)) {
205 ret = cros_ec_sensorhub_ring_add(sensorhub: data);
206 if (ret)
207 return ret;
208 /*
209 * The msg and its data is not under the control of the
210 * ring handler.
211 */
212 return devm_add_action_or_reset(dev,
213 cros_ec_sensorhub_ring_remove,
214 data);
215 }
216
217 } else {
218 /*
219 * If the device has sensors but does not claim to
220 * be a sensor hub, we are in legacy mode.
221 */
222 data->sensor_num = 2;
223 for (i = 0; i < data->sensor_num; i++) {
224 ret = cros_ec_sensorhub_allocate_sensor(parent: dev,
225 sensor_name: "cros-ec-accel-legacy", sensor_num: i);
226 if (ret)
227 return ret;
228 }
229 }
230
231
232 return 0;
233}
234
235#ifdef CONFIG_PM_SLEEP
236/*
237 * When the EC is suspending, we must stop sending interrupt,
238 * we may use the same interrupt line for waking up the device.
239 * Tell the EC to stop sending non-interrupt event on the iio ring.
240 */
241static int cros_ec_sensorhub_suspend(struct device *dev)
242{
243 struct cros_ec_sensorhub *sensorhub = dev_get_drvdata(dev);
244 struct cros_ec_dev *ec = sensorhub->ec;
245
246 if (cros_ec_check_features(ec, feature: EC_FEATURE_MOTION_SENSE_FIFO))
247 return cros_ec_sensorhub_ring_fifo_enable(sensorhub, on: false);
248 return 0;
249}
250
251static int cros_ec_sensorhub_resume(struct device *dev)
252{
253 struct cros_ec_sensorhub *sensorhub = dev_get_drvdata(dev);
254 struct cros_ec_dev *ec = sensorhub->ec;
255
256 if (cros_ec_check_features(ec, feature: EC_FEATURE_MOTION_SENSE_FIFO))
257 return cros_ec_sensorhub_ring_fifo_enable(sensorhub, on: true);
258 return 0;
259}
260#endif
261
262static SIMPLE_DEV_PM_OPS(cros_ec_sensorhub_pm_ops,
263 cros_ec_sensorhub_suspend,
264 cros_ec_sensorhub_resume);
265
266static const struct platform_device_id cros_ec_sensorhub_id[] = {
267 { DRV_NAME, 0 },
268 {}
269};
270MODULE_DEVICE_TABLE(platform, cros_ec_sensorhub_id);
271
272static struct platform_driver cros_ec_sensorhub_driver = {
273 .driver = {
274 .name = DRV_NAME,
275 .pm = &cros_ec_sensorhub_pm_ops,
276 },
277 .probe = cros_ec_sensorhub_probe,
278 .id_table = cros_ec_sensorhub_id,
279};
280
281module_platform_driver(cros_ec_sensorhub_driver);
282
283MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
284MODULE_DESCRIPTION("ChromeOS EC MEMS Sensor Hub Driver");
285MODULE_LICENSE("GPL");
286

source code of linux/drivers/platform/chrome/cros_ec_sensorhub.c