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