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