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
 21static void cros_ec_sensorhub_free_sensor(void *arg)
 22{
 23	struct platform_device *pdev = arg;
 24
 25	platform_device_unregister(pdev);
 26}
 27
 28static 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
 49static 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
124static 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 */
225static 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
235static 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
246static SIMPLE_DEV_PM_OPS(cros_ec_sensorhub_pm_ops,
247		cros_ec_sensorhub_suspend,
248		cros_ec_sensorhub_resume);
249
250static 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
258module_platform_driver(cros_ec_sensorhub_driver);
259
260MODULE_ALIAS("platform:" DRV_NAME);
261MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
262MODULE_DESCRIPTION("ChromeOS EC MEMS Sensor Hub Driver");
263MODULE_LICENSE("GPL");