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v6.8
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
  4 *
  5 * Copyright (C) 2014 Google, Inc.
  6 */
  7
  8#include <linux/dmi.h>
  9#include <linux/kconfig.h>
 10#include <linux/mfd/core.h>
 
 11#include <linux/module.h>
 12#include <linux/mod_devicetable.h>
 13#include <linux/of.h>
 14#include <linux/platform_device.h>
 15#include <linux/platform_data/cros_ec_chardev.h>
 16#include <linux/platform_data/cros_ec_commands.h>
 17#include <linux/platform_data/cros_ec_proto.h>
 18#include <linux/slab.h>
 19
 20#define DRV_NAME "cros-ec-dev"
 21
 22static struct class cros_class = {
 
 23	.name           = "chromeos",
 24};
 25
 26/**
 27 * struct cros_feature_to_name - CrOS feature id to name/short description.
 28 * @id: The feature identifier.
 29 * @name: Device name associated with the feature id.
 30 * @desc: Short name that will be displayed.
 31 */
 32struct cros_feature_to_name {
 33	unsigned int id;
 34	const char *name;
 35	const char *desc;
 36};
 37
 38/**
 39 * struct cros_feature_to_cells - CrOS feature id to mfd cells association.
 40 * @id: The feature identifier.
 41 * @mfd_cells: Pointer to the array of mfd cells that needs to be added.
 42 * @num_cells: Number of mfd cells into the array.
 43 */
 44struct cros_feature_to_cells {
 45	unsigned int id;
 46	const struct mfd_cell *mfd_cells;
 47	unsigned int num_cells;
 48};
 49
 50static const struct cros_feature_to_name cros_mcu_devices[] = {
 51	{
 52		.id	= EC_FEATURE_FINGERPRINT,
 53		.name	= CROS_EC_DEV_FP_NAME,
 54		.desc	= "Fingerprint",
 55	},
 56	{
 57		.id	= EC_FEATURE_ISH,
 58		.name	= CROS_EC_DEV_ISH_NAME,
 59		.desc	= "Integrated Sensor Hub",
 60	},
 61	{
 62		.id	= EC_FEATURE_SCP,
 63		.name	= CROS_EC_DEV_SCP_NAME,
 64		.desc	= "System Control Processor",
 65	},
 66	{
 67		.id	= EC_FEATURE_TOUCHPAD,
 68		.name	= CROS_EC_DEV_TP_NAME,
 69		.desc	= "Touchpad",
 70	},
 71};
 72
 73static const struct mfd_cell cros_ec_cec_cells[] = {
 74	{ .name = "cros-ec-cec", },
 75};
 76
 77static const struct mfd_cell cros_ec_rtc_cells[] = {
 78	{ .name = "cros-ec-rtc", },
 79};
 80
 81static const struct mfd_cell cros_ec_sensorhub_cells[] = {
 82	{ .name = "cros-ec-sensorhub", },
 83};
 84
 85static const struct mfd_cell cros_usbpd_charger_cells[] = {
 86	{ .name = "cros-usbpd-charger", },
 87	{ .name = "cros-usbpd-logger", },
 88};
 89
 90static const struct mfd_cell cros_usbpd_notify_cells[] = {
 91	{ .name = "cros-usbpd-notify", },
 92};
 93
 94static const struct cros_feature_to_cells cros_subdevices[] = {
 95	{
 96		.id		= EC_FEATURE_CEC,
 97		.mfd_cells	= cros_ec_cec_cells,
 98		.num_cells	= ARRAY_SIZE(cros_ec_cec_cells),
 99	},
100	{
101		.id		= EC_FEATURE_RTC,
102		.mfd_cells	= cros_ec_rtc_cells,
103		.num_cells	= ARRAY_SIZE(cros_ec_rtc_cells),
104	},
105	{
106		.id		= EC_FEATURE_USB_PD,
107		.mfd_cells	= cros_usbpd_charger_cells,
108		.num_cells	= ARRAY_SIZE(cros_usbpd_charger_cells),
109	},
110};
111
112static const struct mfd_cell cros_ec_platform_cells[] = {
113	{ .name = "cros-ec-chardev", },
114	{ .name = "cros-ec-debugfs", },
 
115	{ .name = "cros-ec-sysfs", },
116};
117
118static const struct mfd_cell cros_ec_pchg_cells[] = {
119	{ .name = "cros-ec-pchg", },
120};
121
122static const struct mfd_cell cros_ec_lightbar_cells[] = {
123	{ .name = "cros-ec-lightbar", }
124};
125
126static const struct mfd_cell cros_ec_vbc_cells[] = {
127	{ .name = "cros-ec-vbc", }
128};
129
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
130static void cros_ec_class_release(struct device *dev)
131{
132	kfree(to_cros_ec_dev(dev));
133}
134
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
135static int ec_device_probe(struct platform_device *pdev)
136{
137	int retval = -ENOMEM;
138	struct device_node *node;
139	struct device *dev = &pdev->dev;
140	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
141	struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
142	struct ec_response_pchg_count pchg_count;
143	int i;
144
145	if (!ec)
146		return retval;
147
148	dev_set_drvdata(dev, ec);
149	ec->ec_dev = dev_get_drvdata(dev->parent);
150	ec->dev = dev;
151	ec->cmd_offset = ec_platform->cmd_offset;
152	ec->features.flags[0] = -1U; /* Not cached yet */
153	ec->features.flags[1] = -1U; /* Not cached yet */
154	device_initialize(&ec->class_dev);
155
156	for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
157		/*
158		 * Check whether this is actually a dedicated MCU rather
159		 * than an standard EC.
160		 */
161		if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
162			dev_info(dev, "CrOS %s MCU detected\n",
163				 cros_mcu_devices[i].desc);
164			/*
165			 * Help userspace differentiating ECs from other MCU,
166			 * regardless of the probing order.
167			 */
168			ec_platform->ec_name = cros_mcu_devices[i].name;
169			break;
170		}
171	}
172
173	/*
174	 * Add the class device
175	 */
176	ec->class_dev.class = &cros_class;
177	ec->class_dev.parent = dev;
178	ec->class_dev.release = cros_ec_class_release;
179
180	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
181	if (retval) {
182		dev_err(dev, "dev_set_name failed => %d\n", retval);
183		goto failed;
184	}
185
186	retval = device_add(&ec->class_dev);
187	if (retval)
188		goto failed;
189
190	/* check whether this EC is a sensor hub. */
191	if (cros_ec_get_sensor_count(ec) > 0) {
192		retval = mfd_add_hotplug_devices(ec->dev,
193				cros_ec_sensorhub_cells,
194				ARRAY_SIZE(cros_ec_sensorhub_cells));
195		if (retval)
196			dev_err(ec->dev, "failed to add %s subdevice: %d\n",
197				cros_ec_sensorhub_cells->name, retval);
198	}
199
200	/*
201	 * The following subdevices can be detected by sending the
202	 * EC_FEATURE_GET_CMD Embedded Controller device.
203	 */
204	for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
205		if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
206			retval = mfd_add_hotplug_devices(ec->dev,
207						cros_subdevices[i].mfd_cells,
208						cros_subdevices[i].num_cells);
209			if (retval)
210				dev_err(ec->dev,
211					"failed to add %s subdevice: %d\n",
212					cros_subdevices[i].mfd_cells->name,
213					retval);
214		}
215	}
216
217	/*
218	 * Lightbar is a special case. Newer devices support autodetection,
219	 * but older ones do not.
220	 */
221	if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) ||
222	    dmi_match(DMI_PRODUCT_NAME, "Link")) {
223		retval = mfd_add_hotplug_devices(ec->dev,
224					cros_ec_lightbar_cells,
225					ARRAY_SIZE(cros_ec_lightbar_cells));
226		if (retval)
227			dev_warn(ec->dev, "failed to add lightbar: %d\n",
228				 retval);
229	}
230
231	/*
232	 * The PD notifier driver cell is separate since it only needs to be
233	 * explicitly added on platforms that don't have the PD notifier ACPI
234	 * device entry defined.
235	 */
236	if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) {
237		if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
238			retval = mfd_add_hotplug_devices(ec->dev,
239					cros_usbpd_notify_cells,
240					ARRAY_SIZE(cros_usbpd_notify_cells));
241			if (retval)
242				dev_err(ec->dev,
243					"failed to add PD notify devices: %d\n",
244					retval);
245		}
246	}
247
248	/*
249	 * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but
250	 * it can be detected by querying the number of peripheral chargers.
251	 */
252	retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0,
253			     &pchg_count, sizeof(pchg_count));
254	if (retval >= 0 && pchg_count.port_count) {
255		retval = mfd_add_hotplug_devices(ec->dev,
256					cros_ec_pchg_cells,
257					ARRAY_SIZE(cros_ec_pchg_cells));
258		if (retval)
259			dev_warn(ec->dev, "failed to add pchg: %d\n",
260				 retval);
261	}
262
263	/*
264	 * The following subdevices cannot be detected by sending the
265	 * EC_FEATURE_GET_CMD to the Embedded Controller device.
266	 */
267	retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
268					 ARRAY_SIZE(cros_ec_platform_cells));
269	if (retval)
270		dev_warn(ec->dev,
271			 "failed to add cros-ec platform devices: %d\n",
272			 retval);
273
274	/* Check whether this EC instance has a VBC NVRAM */
275	node = ec->ec_dev->dev->of_node;
276	if (of_property_read_bool(node, "google,has-vbc-nvram")) {
277		retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
278						ARRAY_SIZE(cros_ec_vbc_cells));
279		if (retval)
280			dev_warn(ec->dev, "failed to add VBC devices: %d\n",
281				 retval);
282	}
283
284	return 0;
285
286failed:
287	put_device(&ec->class_dev);
288	return retval;
289}
290
291static void ec_device_remove(struct platform_device *pdev)
292{
293	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
294
295	mfd_remove_devices(ec->dev);
296	device_unregister(&ec->class_dev);
 
297}
298
299static const struct platform_device_id cros_ec_id[] = {
300	{ DRV_NAME, 0 },
301	{ /* sentinel */ }
302};
303MODULE_DEVICE_TABLE(platform, cros_ec_id);
304
305static struct platform_driver cros_ec_dev_driver = {
306	.driver = {
307		.name = DRV_NAME,
308	},
309	.id_table = cros_ec_id,
310	.probe = ec_device_probe,
311	.remove_new = ec_device_remove,
312};
313
314static int __init cros_ec_dev_init(void)
315{
316	int ret;
317
318	ret  = class_register(&cros_class);
319	if (ret) {
320		pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
321		return ret;
322	}
323
324	/* Register the driver */
325	ret = platform_driver_register(&cros_ec_dev_driver);
326	if (ret < 0) {
327		pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
328		goto failed_devreg;
329	}
330	return 0;
331
332failed_devreg:
333	class_unregister(&cros_class);
334	return ret;
335}
336
337static void __exit cros_ec_dev_exit(void)
338{
339	platform_driver_unregister(&cros_ec_dev_driver);
340	class_unregister(&cros_class);
341}
342
343module_init(cros_ec_dev_init);
344module_exit(cros_ec_dev_exit);
345
 
346MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
347MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
348MODULE_VERSION("1.0");
349MODULE_LICENSE("GPL");
v5.4
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
  4 *
  5 * Copyright (C) 2014 Google, Inc.
  6 */
  7
 
 
  8#include <linux/mfd/core.h>
  9#include <linux/mfd/cros_ec.h>
 10#include <linux/module.h>
 11#include <linux/mod_devicetable.h>
 12#include <linux/of_platform.h>
 13#include <linux/platform_device.h>
 14#include <linux/platform_data/cros_ec_chardev.h>
 15#include <linux/platform_data/cros_ec_commands.h>
 16#include <linux/platform_data/cros_ec_proto.h>
 17#include <linux/slab.h>
 18
 19#define DRV_NAME "cros-ec-dev"
 20
 21static struct class cros_class = {
 22	.owner          = THIS_MODULE,
 23	.name           = "chromeos",
 24};
 25
 26/**
 27 * cros_feature_to_name - CrOS feature id to name/short description.
 28 * @id: The feature identifier.
 29 * @name: Device name associated with the feature id.
 30 * @desc: Short name that will be displayed.
 31 */
 32struct cros_feature_to_name {
 33	unsigned int id;
 34	const char *name;
 35	const char *desc;
 36};
 37
 38/**
 39 * cros_feature_to_cells - CrOS feature id to mfd cells association.
 40 * @id: The feature identifier.
 41 * @mfd_cells: Pointer to the array of mfd cells that needs to be added.
 42 * @num_cells: Number of mfd cells into the array.
 43 */
 44struct cros_feature_to_cells {
 45	unsigned int id;
 46	const struct mfd_cell *mfd_cells;
 47	unsigned int num_cells;
 48};
 49
 50static const struct cros_feature_to_name cros_mcu_devices[] = {
 51	{
 52		.id	= EC_FEATURE_FINGERPRINT,
 53		.name	= CROS_EC_DEV_FP_NAME,
 54		.desc	= "Fingerprint",
 55	},
 56	{
 57		.id	= EC_FEATURE_ISH,
 58		.name	= CROS_EC_DEV_ISH_NAME,
 59		.desc	= "Integrated Sensor Hub",
 60	},
 61	{
 62		.id	= EC_FEATURE_SCP,
 63		.name	= CROS_EC_DEV_SCP_NAME,
 64		.desc	= "System Control Processor",
 65	},
 66	{
 67		.id	= EC_FEATURE_TOUCHPAD,
 68		.name	= CROS_EC_DEV_TP_NAME,
 69		.desc	= "Touchpad",
 70	},
 71};
 72
 73static const struct mfd_cell cros_ec_cec_cells[] = {
 74	{ .name = "cros-ec-cec", },
 75};
 76
 77static const struct mfd_cell cros_ec_rtc_cells[] = {
 78	{ .name = "cros-ec-rtc", },
 79};
 80
 
 
 
 
 81static const struct mfd_cell cros_usbpd_charger_cells[] = {
 82	{ .name = "cros-usbpd-charger", },
 83	{ .name = "cros-usbpd-logger", },
 84};
 85
 
 
 
 
 86static const struct cros_feature_to_cells cros_subdevices[] = {
 87	{
 88		.id		= EC_FEATURE_CEC,
 89		.mfd_cells	= cros_ec_cec_cells,
 90		.num_cells	= ARRAY_SIZE(cros_ec_cec_cells),
 91	},
 92	{
 93		.id		= EC_FEATURE_RTC,
 94		.mfd_cells	= cros_ec_rtc_cells,
 95		.num_cells	= ARRAY_SIZE(cros_ec_rtc_cells),
 96	},
 97	{
 98		.id		= EC_FEATURE_USB_PD,
 99		.mfd_cells	= cros_usbpd_charger_cells,
100		.num_cells	= ARRAY_SIZE(cros_usbpd_charger_cells),
101	},
102};
103
104static const struct mfd_cell cros_ec_platform_cells[] = {
105	{ .name = "cros-ec-chardev", },
106	{ .name = "cros-ec-debugfs", },
107	{ .name = "cros-ec-lightbar", },
108	{ .name = "cros-ec-sysfs", },
109};
110
 
 
 
 
 
 
 
 
111static const struct mfd_cell cros_ec_vbc_cells[] = {
112	{ .name = "cros-ec-vbc", }
113};
114
115static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
116{
117	struct cros_ec_command *msg;
118	int ret;
119
120	if (ec->features[0] == -1U && ec->features[1] == -1U) {
121		/* features bitmap not read yet */
122		msg = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
123		if (!msg)
124			return -ENOMEM;
125
126		msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
127		msg->insize = sizeof(ec->features);
128
129		ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
130		if (ret < 0) {
131			dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
132				 ret, msg->result);
133			memset(ec->features, 0, sizeof(ec->features));
134		} else {
135			memcpy(ec->features, msg->data, sizeof(ec->features));
136		}
137
138		dev_dbg(ec->dev, "EC features %08x %08x\n",
139			ec->features[0], ec->features[1]);
140
141		kfree(msg);
142	}
143
144	return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
145}
146
147static void cros_ec_class_release(struct device *dev)
148{
149	kfree(to_cros_ec_dev(dev));
150}
151
152static void cros_ec_sensors_register(struct cros_ec_dev *ec)
153{
154	/*
155	 * Issue a command to get the number of sensor reported.
156	 * Build an array of sensors driver and register them all.
157	 */
158	int ret, i, id, sensor_num;
159	struct mfd_cell *sensor_cells;
160	struct cros_ec_sensor_platform *sensor_platforms;
161	int sensor_type[MOTIONSENSE_TYPE_MAX];
162	struct ec_params_motion_sense *params;
163	struct ec_response_motion_sense *resp;
164	struct cros_ec_command *msg;
165
166	msg = kzalloc(sizeof(struct cros_ec_command) +
167		      max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
168	if (msg == NULL)
169		return;
170
171	msg->version = 2;
172	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
173	msg->outsize = sizeof(*params);
174	msg->insize = sizeof(*resp);
175
176	params = (struct ec_params_motion_sense *)msg->data;
177	params->cmd = MOTIONSENSE_CMD_DUMP;
178
179	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
180	if (ret < 0) {
181		dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n",
182			 ret, msg->result);
183		goto error;
184	}
185
186	resp = (struct ec_response_motion_sense *)msg->data;
187	sensor_num = resp->dump.sensor_count;
188	/*
189	 * Allocate 2 extra sensors if lid angle sensor and/or FIFO are needed.
190	 */
191	sensor_cells = kcalloc(sensor_num + 2, sizeof(struct mfd_cell),
192			       GFP_KERNEL);
193	if (sensor_cells == NULL)
194		goto error;
195
196	sensor_platforms = kcalloc(sensor_num,
197				   sizeof(struct cros_ec_sensor_platform),
198				   GFP_KERNEL);
199	if (sensor_platforms == NULL)
200		goto error_platforms;
201
202	memset(sensor_type, 0, sizeof(sensor_type));
203	id = 0;
204	for (i = 0; i < sensor_num; i++) {
205		params->cmd = MOTIONSENSE_CMD_INFO;
206		params->info.sensor_num = i;
207		ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
208		if (ret < 0) {
209			dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n",
210				 i, ret, msg->result);
211			continue;
212		}
213		switch (resp->info.type) {
214		case MOTIONSENSE_TYPE_ACCEL:
215			sensor_cells[id].name = "cros-ec-accel";
216			break;
217		case MOTIONSENSE_TYPE_BARO:
218			sensor_cells[id].name = "cros-ec-baro";
219			break;
220		case MOTIONSENSE_TYPE_GYRO:
221			sensor_cells[id].name = "cros-ec-gyro";
222			break;
223		case MOTIONSENSE_TYPE_MAG:
224			sensor_cells[id].name = "cros-ec-mag";
225			break;
226		case MOTIONSENSE_TYPE_PROX:
227			sensor_cells[id].name = "cros-ec-prox";
228			break;
229		case MOTIONSENSE_TYPE_LIGHT:
230			sensor_cells[id].name = "cros-ec-light";
231			break;
232		case MOTIONSENSE_TYPE_ACTIVITY:
233			sensor_cells[id].name = "cros-ec-activity";
234			break;
235		default:
236			dev_warn(ec->dev, "unknown type %d\n", resp->info.type);
237			continue;
238		}
239		sensor_platforms[id].sensor_num = i;
240		sensor_cells[id].id = sensor_type[resp->info.type];
241		sensor_cells[id].platform_data = &sensor_platforms[id];
242		sensor_cells[id].pdata_size =
243			sizeof(struct cros_ec_sensor_platform);
244
245		sensor_type[resp->info.type]++;
246		id++;
247	}
248
249	if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
250		ec->has_kb_wake_angle = true;
251
252	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
253		sensor_cells[id].name = "cros-ec-ring";
254		id++;
255	}
256	if (cros_ec_check_features(ec,
257				EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
258		sensor_cells[id].name = "cros-ec-lid-angle";
259		id++;
260	}
261
262	ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
263			      NULL, 0, NULL);
264	if (ret)
265		dev_err(ec->dev, "failed to add EC sensors\n");
266
267	kfree(sensor_platforms);
268error_platforms:
269	kfree(sensor_cells);
270error:
271	kfree(msg);
272}
273
274static struct cros_ec_sensor_platform sensor_platforms[] = {
275	{ .sensor_num = 0 },
276	{ .sensor_num = 1 }
277};
278
279static const struct mfd_cell cros_ec_accel_legacy_cells[] = {
280	{
281		.name = "cros-ec-accel-legacy",
282		.platform_data = &sensor_platforms[0],
283		.pdata_size = sizeof(struct cros_ec_sensor_platform),
284	},
285	{
286		.name = "cros-ec-accel-legacy",
287		.platform_data = &sensor_platforms[1],
288		.pdata_size = sizeof(struct cros_ec_sensor_platform),
289	}
290};
291
292static void cros_ec_accel_legacy_register(struct cros_ec_dev *ec)
293{
294	struct cros_ec_device *ec_dev = ec->ec_dev;
295	u8 status;
296	int ret;
297
298	/*
299	 * ECs that need legacy support are the main EC, directly connected to
300	 * the AP.
301	 */
302	if (ec->cmd_offset != 0)
303		return;
304
305	/*
306	 * Check if EC supports direct memory reads and if EC has
307	 * accelerometers.
308	 */
309	if (ec_dev->cmd_readmem) {
310		ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS, 1,
311					  &status);
312		if (ret < 0) {
313			dev_warn(ec->dev, "EC direct read error.\n");
314			return;
315		}
316
317		/* Check if EC has accelerometers. */
318		if (!(status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
319			dev_info(ec->dev, "EC does not have accelerometers.\n");
320			return;
321		}
322	}
323
324	/*
325	 * The device may still support accelerometers:
326	 * it would be an older ARM based device that do not suppor the
327	 * EC_CMD_GET_FEATURES command.
328	 *
329	 * Register 2 accelerometers, we will fail in the IIO driver if there
330	 * are no sensors.
331	 */
332	ret = mfd_add_hotplug_devices(ec->dev, cros_ec_accel_legacy_cells,
333				      ARRAY_SIZE(cros_ec_accel_legacy_cells));
334	if (ret)
335		dev_err(ec_dev->dev, "failed to add EC sensors\n");
336}
337
338static int ec_device_probe(struct platform_device *pdev)
339{
340	int retval = -ENOMEM;
341	struct device_node *node;
342	struct device *dev = &pdev->dev;
343	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
344	struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
 
345	int i;
346
347	if (!ec)
348		return retval;
349
350	dev_set_drvdata(dev, ec);
351	ec->ec_dev = dev_get_drvdata(dev->parent);
352	ec->dev = dev;
353	ec->cmd_offset = ec_platform->cmd_offset;
354	ec->features[0] = -1U; /* Not cached yet */
355	ec->features[1] = -1U; /* Not cached yet */
356	device_initialize(&ec->class_dev);
357
358	for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
359		/*
360		 * Check whether this is actually a dedicated MCU rather
361		 * than an standard EC.
362		 */
363		if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
364			dev_info(dev, "CrOS %s MCU detected\n",
365				 cros_mcu_devices[i].desc);
366			/*
367			 * Help userspace differentiating ECs from other MCU,
368			 * regardless of the probing order.
369			 */
370			ec_platform->ec_name = cros_mcu_devices[i].name;
371			break;
372		}
373	}
374
375	/*
376	 * Add the class device
377	 */
378	ec->class_dev.class = &cros_class;
379	ec->class_dev.parent = dev;
380	ec->class_dev.release = cros_ec_class_release;
381
382	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
383	if (retval) {
384		dev_err(dev, "dev_set_name failed => %d\n", retval);
385		goto failed;
386	}
387
388	retval = device_add(&ec->class_dev);
389	if (retval)
390		goto failed;
391
392	/* check whether this EC is a sensor hub. */
393	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
394		cros_ec_sensors_register(ec);
395	else
396		/* Workaroud for older EC firmware */
397		cros_ec_accel_legacy_register(ec);
 
 
 
398
399	/*
400	 * The following subdevices can be detected by sending the
401	 * EC_FEATURE_GET_CMD Embedded Controller device.
402	 */
403	for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
404		if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
405			retval = mfd_add_hotplug_devices(ec->dev,
406						cros_subdevices[i].mfd_cells,
407						cros_subdevices[i].num_cells);
408			if (retval)
409				dev_err(ec->dev,
410					"failed to add %s subdevice: %d\n",
411					cros_subdevices[i].mfd_cells->name,
412					retval);
413		}
414	}
415
416	/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
417	 * The following subdevices cannot be detected by sending the
418	 * EC_FEATURE_GET_CMD to the Embedded Controller device.
419	 */
420	retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
421					 ARRAY_SIZE(cros_ec_platform_cells));
422	if (retval)
423		dev_warn(ec->dev,
424			 "failed to add cros-ec platform devices: %d\n",
425			 retval);
426
427	/* Check whether this EC instance has a VBC NVRAM */
428	node = ec->ec_dev->dev->of_node;
429	if (of_property_read_bool(node, "google,has-vbc-nvram")) {
430		retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
431						ARRAY_SIZE(cros_ec_vbc_cells));
432		if (retval)
433			dev_warn(ec->dev, "failed to add VBC devices: %d\n",
434				 retval);
435	}
436
437	return 0;
438
439failed:
440	put_device(&ec->class_dev);
441	return retval;
442}
443
444static int ec_device_remove(struct platform_device *pdev)
445{
446	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
447
448	mfd_remove_devices(ec->dev);
449	device_unregister(&ec->class_dev);
450	return 0;
451}
452
453static const struct platform_device_id cros_ec_id[] = {
454	{ DRV_NAME, 0 },
455	{ /* sentinel */ }
456};
457MODULE_DEVICE_TABLE(platform, cros_ec_id);
458
459static struct platform_driver cros_ec_dev_driver = {
460	.driver = {
461		.name = DRV_NAME,
462	},
463	.id_table = cros_ec_id,
464	.probe = ec_device_probe,
465	.remove = ec_device_remove,
466};
467
468static int __init cros_ec_dev_init(void)
469{
470	int ret;
471
472	ret  = class_register(&cros_class);
473	if (ret) {
474		pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
475		return ret;
476	}
477
478	/* Register the driver */
479	ret = platform_driver_register(&cros_ec_dev_driver);
480	if (ret < 0) {
481		pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
482		goto failed_devreg;
483	}
484	return 0;
485
486failed_devreg:
487	class_unregister(&cros_class);
488	return ret;
489}
490
491static void __exit cros_ec_dev_exit(void)
492{
493	platform_driver_unregister(&cros_ec_dev_driver);
494	class_unregister(&cros_class);
495}
496
497module_init(cros_ec_dev_init);
498module_exit(cros_ec_dev_exit);
499
500MODULE_ALIAS("platform:" DRV_NAME);
501MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
502MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
503MODULE_VERSION("1.0");
504MODULE_LICENSE("GPL");