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