cros_ec_dev.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * ChromeOS Embedded Controller
  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_gpio_cells[] = {
 78	{ .name = "cros-ec-gpio", },
 79};
 80
 81static const struct mfd_cell cros_ec_rtc_cells[] = {
 82	{ .name = "cros-ec-rtc", },
 83};
 84
 85static const struct mfd_cell cros_ec_sensorhub_cells[] = {
 86	{ .name = "cros-ec-sensorhub", },
 87};
 88
 89static const struct mfd_cell cros_usbpd_charger_cells[] = {
 90	{ .name = "cros-usbpd-charger", },
 91	{ .name = "cros-usbpd-logger", },
 92};
 93
 94static const struct mfd_cell cros_usbpd_notify_cells[] = {
 95	{ .name = "cros-usbpd-notify", },
 96};
 97
 98static const struct mfd_cell cros_ec_wdt_cells[] = {
 99	{ .name = "cros-ec-wdt", }
100};
101
102static const struct mfd_cell cros_ec_led_cells[] = {
103	{ .name = "cros-ec-led", },
104};
105
106static const struct mfd_cell cros_ec_keyboard_leds_cells[] = {
107	{ .name = "cros-keyboard-leds", },
108};
109
110static const struct mfd_cell cros_ec_ucsi_cells[] = {
111	{ .name = "cros_ec_ucsi", },
112};
113
114static const struct mfd_cell cros_ec_charge_control_cells[] = {
115	{ .name = "cros-charge-control", },
116};
117
118static const struct cros_feature_to_cells cros_subdevices[] = {
119	{
120		.id		= EC_FEATURE_CEC,
121		.mfd_cells	= cros_ec_cec_cells,
122		.num_cells	= ARRAY_SIZE(cros_ec_cec_cells),
123	},
124	{
125		.id		= EC_FEATURE_GPIO,
126		.mfd_cells	= cros_ec_gpio_cells,
127		.num_cells	= ARRAY_SIZE(cros_ec_gpio_cells),
128	},
129	{
130		.id		= EC_FEATURE_RTC,
131		.mfd_cells	= cros_ec_rtc_cells,
132		.num_cells	= ARRAY_SIZE(cros_ec_rtc_cells),
133	},
134	{
135		.id		= EC_FEATURE_UCSI_PPM,
136		.mfd_cells	= cros_ec_ucsi_cells,
137		.num_cells	= ARRAY_SIZE(cros_ec_ucsi_cells),
138	},
139	{
140		.id		= EC_FEATURE_HANG_DETECT,
141		.mfd_cells	= cros_ec_wdt_cells,
142		.num_cells	= ARRAY_SIZE(cros_ec_wdt_cells),
143	},
144	{
145		.id		= EC_FEATURE_LED,
146		.mfd_cells	= cros_ec_led_cells,
147		.num_cells	= ARRAY_SIZE(cros_ec_led_cells),
148	},
149	{
150		.id		= EC_FEATURE_PWM_KEYB,
151		.mfd_cells	= cros_ec_keyboard_leds_cells,
152		.num_cells	= ARRAY_SIZE(cros_ec_keyboard_leds_cells),
153	},
154	{
155		.id		= EC_FEATURE_CHARGER,
156		.mfd_cells	= cros_ec_charge_control_cells,
157		.num_cells	= ARRAY_SIZE(cros_ec_charge_control_cells),
158	},
159};
160
161static const struct mfd_cell cros_ec_platform_cells[] = {
162	{ .name = "cros-ec-chardev", },
163	{ .name = "cros-ec-debugfs", },
164	{ .name = "cros-ec-hwmon", },
165	{ .name = "cros-ec-sysfs", },
166};
167
168static const struct mfd_cell cros_ec_pchg_cells[] = {
169	{ .name = "cros-ec-pchg", },
170};
171
172static const struct mfd_cell cros_ec_lightbar_cells[] = {
173	{ .name = "cros-ec-lightbar", }
174};
175
176static const struct mfd_cell cros_ec_vbc_cells[] = {
177	{ .name = "cros-ec-vbc", }
178};
179
180static void cros_ec_class_release(struct device *dev)
181{
182	kfree(to_cros_ec_dev(dev));
183}
184
185static int ec_device_probe(struct platform_device *pdev)
186{
187	int retval = -ENOMEM;
188	struct device_node *node;
189	struct device *dev = &pdev->dev;
190	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
191	struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
192	struct ec_response_pchg_count pchg_count;
193	int i;
194
195	if (!ec)
196		return retval;
197
198	dev_set_drvdata(dev, ec);
199	ec->ec_dev = dev_get_drvdata(dev->parent);
200	ec->dev = dev;
201	ec->cmd_offset = ec_platform->cmd_offset;
202	ec->features.flags[0] = -1U; /* Not cached yet */
203	ec->features.flags[1] = -1U; /* Not cached yet */
204	device_initialize(&ec->class_dev);
205
206	for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
207		/*
208		 * Check whether this is actually a dedicated MCU rather
209		 * than an standard EC.
210		 */
211		if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
212			dev_info(dev, "CrOS %s MCU detected\n",
213				 cros_mcu_devices[i].desc);
214			/*
215			 * Help userspace differentiating ECs from other MCU,
216			 * regardless of the probing order.
217			 */
218			ec_platform->ec_name = cros_mcu_devices[i].name;
219			break;
220		}
221	}
222
223	/*
224	 * Add the class device
225	 */
226	ec->class_dev.class = &cros_class;
227	ec->class_dev.parent = dev;
228	ec->class_dev.release = cros_ec_class_release;
229
230	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
231	if (retval) {
232		dev_err(dev, "dev_set_name failed => %d\n", retval);
233		goto failed;
234	}
235
236	retval = device_add(&ec->class_dev);
237	if (retval)
238		goto failed;
239
240	/* check whether this EC is a sensor hub. */
241	if (cros_ec_get_sensor_count(ec) > 0) {
242		retval = mfd_add_hotplug_devices(ec->dev,
243				cros_ec_sensorhub_cells,
244				ARRAY_SIZE(cros_ec_sensorhub_cells));
245		if (retval)
246			dev_err(ec->dev, "failed to add %s subdevice: %d\n",
247				cros_ec_sensorhub_cells->name, retval);
248	}
249
250	/*
251	 * The following subdevices can be detected by sending the
252	 * EC_FEATURE_GET_CMD Embedded Controller device.
253	 */
254	for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
255		if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
256			retval = mfd_add_hotplug_devices(ec->dev,
257						cros_subdevices[i].mfd_cells,
258						cros_subdevices[i].num_cells);
259			if (retval)
260				dev_err(ec->dev,
261					"failed to add %s subdevice: %d\n",
262					cros_subdevices[i].mfd_cells->name,
263					retval);
264		}
265	}
266
267	/*
268	 * UCSI provides power supply information so we don't need to separately
269	 * load the cros_usbpd_charger driver.
270	 */
271	if (cros_ec_check_features(ec, EC_FEATURE_USB_PD) &&
272	    !cros_ec_check_features(ec, EC_FEATURE_UCSI_PPM)) {
273		retval = mfd_add_hotplug_devices(ec->dev,
274						 cros_usbpd_charger_cells,
275						 ARRAY_SIZE(cros_usbpd_charger_cells));
276
277		if (retval)
278			dev_warn(ec->dev, "failed to add usbpd-charger: %d\n",
279				 retval);
280	}
281
282	/*
283	 * Lightbar is a special case. Newer devices support autodetection,
284	 * but older ones do not.
285	 */
286	if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) ||
287	    dmi_match(DMI_PRODUCT_NAME, "Link")) {
288		retval = mfd_add_hotplug_devices(ec->dev,
289					cros_ec_lightbar_cells,
290					ARRAY_SIZE(cros_ec_lightbar_cells));
291		if (retval)
292			dev_warn(ec->dev, "failed to add lightbar: %d\n",
293				 retval);
294	}
295
296	/*
297	 * The PD notifier driver cell is separate since it only needs to be
298	 * explicitly added on platforms that don't have the PD notifier ACPI
299	 * device entry defined.
300	 */
301	if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) {
302		if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
303			retval = mfd_add_hotplug_devices(ec->dev,
304					cros_usbpd_notify_cells,
305					ARRAY_SIZE(cros_usbpd_notify_cells));
306			if (retval)
307				dev_err(ec->dev,
308					"failed to add PD notify devices: %d\n",
309					retval);
310		}
311	}
312
313	/*
314	 * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but
315	 * it can be detected by querying the number of peripheral chargers.
316	 */
317	retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0,
318			     &pchg_count, sizeof(pchg_count));
319	if (retval >= 0 && pchg_count.port_count) {
320		retval = mfd_add_hotplug_devices(ec->dev,
321					cros_ec_pchg_cells,
322					ARRAY_SIZE(cros_ec_pchg_cells));
323		if (retval)
324			dev_warn(ec->dev, "failed to add pchg: %d\n",
325				 retval);
326	}
327
328	/*
329	 * The following subdevices cannot be detected by sending the
330	 * EC_FEATURE_GET_CMD to the Embedded Controller device.
331	 */
332	retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
333					 ARRAY_SIZE(cros_ec_platform_cells));
334	if (retval)
335		dev_warn(ec->dev,
336			 "failed to add cros-ec platform devices: %d\n",
337			 retval);
338
339	/* Check whether this EC instance has a VBC NVRAM */
340	node = ec->ec_dev->dev->of_node;
341	if (of_property_read_bool(node, "google,has-vbc-nvram")) {
342		retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
343						ARRAY_SIZE(cros_ec_vbc_cells));
344		if (retval)
345			dev_warn(ec->dev, "failed to add VBC devices: %d\n",
346				 retval);
347	}
348
349	return 0;
350
351failed:
352	put_device(&ec->class_dev);
353	return retval;
354}
355
356static void ec_device_remove(struct platform_device *pdev)
357{
358	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
359
360	mfd_remove_devices(ec->dev);
361	device_unregister(&ec->class_dev);
362}
363
364static const struct platform_device_id cros_ec_id[] = {
365	{ DRV_NAME, 0 },
366	{ /* sentinel */ }
367};
368MODULE_DEVICE_TABLE(platform, cros_ec_id);
369
370static struct platform_driver cros_ec_dev_driver = {
371	.driver = {
372		.name = DRV_NAME,
373	},
374	.id_table = cros_ec_id,
375	.probe = ec_device_probe,
376	.remove = ec_device_remove,
377};
378
379static int __init cros_ec_dev_init(void)
380{
381	int ret;
382
383	ret = class_register(&cros_class);
384	if (ret) {
385		pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
386		return ret;
387	}
388
389	ret = platform_driver_register(&cros_ec_dev_driver);
390	if (ret) {
391		pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
392		class_unregister(&cros_class);
393	}
394	return ret;
395}
396
397static void __exit cros_ec_dev_exit(void)
398{
399	platform_driver_unregister(&cros_ec_dev_driver);
400	class_unregister(&cros_class);
401}
402
403module_init(cros_ec_dev_init);
404module_exit(cros_ec_dev_exit);
405
406MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
407MODULE_DESCRIPTION("ChromeOS Embedded Controller");
408MODULE_VERSION("1.0");
409MODULE_LICENSE("GPL");