xref: /linux/drivers/mfd/cros_ec_dev.c (revision 80739fd00c7ea1315d362ce889bef499452913ef)
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 
22 static 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  */
32 struct 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  */
44 struct cros_feature_to_cells {
45 	unsigned int id;
46 	const struct mfd_cell *mfd_cells;
47 	unsigned int num_cells;
48 };
49 
50 static 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 
73 static const struct mfd_cell cros_ec_cec_cells[] = {
74 	{ .name = "cros-ec-cec", },
75 };
76 
77 static const struct mfd_cell cros_ec_gpio_cells[] = {
78 	{ .name = "cros-ec-gpio", },
79 };
80 
81 static const struct mfd_cell cros_ec_rtc_cells[] = {
82 	{ .name = "cros-ec-rtc", },
83 };
84 
85 static const struct mfd_cell cros_ec_sensorhub_cells[] = {
86 	{ .name = "cros-ec-sensorhub", },
87 };
88 
89 static const struct mfd_cell cros_usbpd_charger_cells[] = {
90 	{ .name = "cros-charge-control", },
91 	{ .name = "cros-usbpd-charger", },
92 	{ .name = "cros-usbpd-logger", },
93 };
94 
95 static const struct mfd_cell cros_usbpd_notify_cells[] = {
96 	{ .name = "cros-usbpd-notify", },
97 };
98 
99 static const struct mfd_cell cros_ec_wdt_cells[] = {
100 	{ .name = "cros-ec-wdt", }
101 };
102 
103 static const struct mfd_cell cros_ec_led_cells[] = {
104 	{ .name = "cros-ec-led", },
105 };
106 
107 static const struct mfd_cell cros_ec_keyboard_leds_cells[] = {
108 	{ .name = "cros-keyboard-leds", },
109 };
110 
111 static const struct mfd_cell cros_ec_ucsi_cells[] = {
112 	{ .name = "cros_ec_ucsi", },
113 };
114 
115 static const struct cros_feature_to_cells cros_subdevices[] = {
116 	{
117 		.id		= EC_FEATURE_CEC,
118 		.mfd_cells	= cros_ec_cec_cells,
119 		.num_cells	= ARRAY_SIZE(cros_ec_cec_cells),
120 	},
121 	{
122 		.id		= EC_FEATURE_GPIO,
123 		.mfd_cells	= cros_ec_gpio_cells,
124 		.num_cells	= ARRAY_SIZE(cros_ec_gpio_cells),
125 	},
126 	{
127 		.id		= EC_FEATURE_RTC,
128 		.mfd_cells	= cros_ec_rtc_cells,
129 		.num_cells	= ARRAY_SIZE(cros_ec_rtc_cells),
130 	},
131 	{
132 		.id		= EC_FEATURE_UCSI_PPM,
133 		.mfd_cells	= cros_ec_ucsi_cells,
134 		.num_cells	= ARRAY_SIZE(cros_ec_ucsi_cells),
135 	},
136 	{
137 		.id		= EC_FEATURE_HANG_DETECT,
138 		.mfd_cells	= cros_ec_wdt_cells,
139 		.num_cells	= ARRAY_SIZE(cros_ec_wdt_cells),
140 	},
141 	{
142 		.id		= EC_FEATURE_LED,
143 		.mfd_cells	= cros_ec_led_cells,
144 		.num_cells	= ARRAY_SIZE(cros_ec_led_cells),
145 	},
146 	{
147 		.id		= EC_FEATURE_PWM_KEYB,
148 		.mfd_cells	= cros_ec_keyboard_leds_cells,
149 		.num_cells	= ARRAY_SIZE(cros_ec_keyboard_leds_cells),
150 	},
151 };
152 
153 static const struct mfd_cell cros_ec_platform_cells[] = {
154 	{ .name = "cros-ec-chardev", },
155 	{ .name = "cros-ec-debugfs", },
156 	{ .name = "cros-ec-hwmon", },
157 	{ .name = "cros-ec-sysfs", },
158 };
159 
160 static const struct mfd_cell cros_ec_pchg_cells[] = {
161 	{ .name = "cros-ec-pchg", },
162 };
163 
164 static const struct mfd_cell cros_ec_lightbar_cells[] = {
165 	{ .name = "cros-ec-lightbar", }
166 };
167 
168 static const struct mfd_cell cros_ec_vbc_cells[] = {
169 	{ .name = "cros-ec-vbc", }
170 };
171 
cros_ec_class_release(struct device * dev)172 static void cros_ec_class_release(struct device *dev)
173 {
174 	kfree(to_cros_ec_dev(dev));
175 }
176 
ec_device_probe(struct platform_device * pdev)177 static int ec_device_probe(struct platform_device *pdev)
178 {
179 	int retval = -ENOMEM;
180 	struct device_node *node;
181 	struct device *dev = &pdev->dev;
182 	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
183 	struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
184 	struct ec_response_pchg_count pchg_count;
185 	int i;
186 
187 	if (!ec)
188 		return retval;
189 
190 	dev_set_drvdata(dev, ec);
191 	ec->ec_dev = dev_get_drvdata(dev->parent);
192 	ec->dev = dev;
193 	ec->cmd_offset = ec_platform->cmd_offset;
194 	ec->features.flags[0] = -1U; /* Not cached yet */
195 	ec->features.flags[1] = -1U; /* Not cached yet */
196 	device_initialize(&ec->class_dev);
197 
198 	for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
199 		/*
200 		 * Check whether this is actually a dedicated MCU rather
201 		 * than an standard EC.
202 		 */
203 		if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
204 			dev_info(dev, "CrOS %s MCU detected\n",
205 				 cros_mcu_devices[i].desc);
206 			/*
207 			 * Help userspace differentiating ECs from other MCU,
208 			 * regardless of the probing order.
209 			 */
210 			ec_platform->ec_name = cros_mcu_devices[i].name;
211 			break;
212 		}
213 	}
214 
215 	/*
216 	 * Add the class device
217 	 */
218 	ec->class_dev.class = &cros_class;
219 	ec->class_dev.parent = dev;
220 	ec->class_dev.release = cros_ec_class_release;
221 
222 	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
223 	if (retval) {
224 		dev_err(dev, "dev_set_name failed => %d\n", retval);
225 		goto failed;
226 	}
227 
228 	retval = device_add(&ec->class_dev);
229 	if (retval)
230 		goto failed;
231 
232 	/* check whether this EC is a sensor hub. */
233 	if (cros_ec_get_sensor_count(ec) > 0) {
234 		retval = mfd_add_hotplug_devices(ec->dev,
235 				cros_ec_sensorhub_cells,
236 				ARRAY_SIZE(cros_ec_sensorhub_cells));
237 		if (retval)
238 			dev_err(ec->dev, "failed to add %s subdevice: %d\n",
239 				cros_ec_sensorhub_cells->name, retval);
240 	}
241 
242 	/*
243 	 * The following subdevices can be detected by sending the
244 	 * EC_FEATURE_GET_CMD Embedded Controller device.
245 	 */
246 	for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
247 		if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
248 			retval = mfd_add_hotplug_devices(ec->dev,
249 						cros_subdevices[i].mfd_cells,
250 						cros_subdevices[i].num_cells);
251 			if (retval)
252 				dev_err(ec->dev,
253 					"failed to add %s subdevice: %d\n",
254 					cros_subdevices[i].mfd_cells->name,
255 					retval);
256 		}
257 	}
258 
259 	/*
260 	 * UCSI provides power supply information so we don't need to separately
261 	 * load the cros_usbpd_charger driver.
262 	 */
263 	if (cros_ec_check_features(ec, EC_FEATURE_USB_PD) &&
264 	    !cros_ec_check_features(ec, EC_FEATURE_UCSI_PPM)) {
265 		retval = mfd_add_hotplug_devices(ec->dev,
266 						 cros_usbpd_charger_cells,
267 						 ARRAY_SIZE(cros_usbpd_charger_cells));
268 
269 		if (retval)
270 			dev_warn(ec->dev, "failed to add usbpd-charger: %d\n",
271 				 retval);
272 	}
273 
274 	/*
275 	 * Lightbar is a special case. Newer devices support autodetection,
276 	 * but older ones do not.
277 	 */
278 	if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) ||
279 	    dmi_match(DMI_PRODUCT_NAME, "Link")) {
280 		retval = mfd_add_hotplug_devices(ec->dev,
281 					cros_ec_lightbar_cells,
282 					ARRAY_SIZE(cros_ec_lightbar_cells));
283 		if (retval)
284 			dev_warn(ec->dev, "failed to add lightbar: %d\n",
285 				 retval);
286 	}
287 
288 	/*
289 	 * The PD notifier driver cell is separate since it only needs to be
290 	 * explicitly added on platforms that don't have the PD notifier ACPI
291 	 * device entry defined.
292 	 */
293 	if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) {
294 		if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
295 			retval = mfd_add_hotplug_devices(ec->dev,
296 					cros_usbpd_notify_cells,
297 					ARRAY_SIZE(cros_usbpd_notify_cells));
298 			if (retval)
299 				dev_err(ec->dev,
300 					"failed to add PD notify devices: %d\n",
301 					retval);
302 		}
303 	}
304 
305 	/*
306 	 * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but
307 	 * it can be detected by querying the number of peripheral chargers.
308 	 */
309 	retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0,
310 			     &pchg_count, sizeof(pchg_count));
311 	if (retval >= 0 && pchg_count.port_count) {
312 		retval = mfd_add_hotplug_devices(ec->dev,
313 					cros_ec_pchg_cells,
314 					ARRAY_SIZE(cros_ec_pchg_cells));
315 		if (retval)
316 			dev_warn(ec->dev, "failed to add pchg: %d\n",
317 				 retval);
318 	}
319 
320 	/*
321 	 * The following subdevices cannot be detected by sending the
322 	 * EC_FEATURE_GET_CMD to the Embedded Controller device.
323 	 */
324 	retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
325 					 ARRAY_SIZE(cros_ec_platform_cells));
326 	if (retval)
327 		dev_warn(ec->dev,
328 			 "failed to add cros-ec platform devices: %d\n",
329 			 retval);
330 
331 	/* Check whether this EC instance has a VBC NVRAM */
332 	node = ec->ec_dev->dev->of_node;
333 	if (of_property_read_bool(node, "google,has-vbc-nvram")) {
334 		retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
335 						ARRAY_SIZE(cros_ec_vbc_cells));
336 		if (retval)
337 			dev_warn(ec->dev, "failed to add VBC devices: %d\n",
338 				 retval);
339 	}
340 
341 	return 0;
342 
343 failed:
344 	put_device(&ec->class_dev);
345 	return retval;
346 }
347 
ec_device_remove(struct platform_device * pdev)348 static void ec_device_remove(struct platform_device *pdev)
349 {
350 	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
351 
352 	mfd_remove_devices(ec->dev);
353 	device_unregister(&ec->class_dev);
354 }
355 
356 static const struct platform_device_id cros_ec_id[] = {
357 	{ DRV_NAME, 0 },
358 	{ /* sentinel */ }
359 };
360 MODULE_DEVICE_TABLE(platform, cros_ec_id);
361 
362 static struct platform_driver cros_ec_dev_driver = {
363 	.driver = {
364 		.name = DRV_NAME,
365 	},
366 	.id_table = cros_ec_id,
367 	.probe = ec_device_probe,
368 	.remove = ec_device_remove,
369 };
370 
cros_ec_dev_init(void)371 static int __init cros_ec_dev_init(void)
372 {
373 	int ret;
374 
375 	ret = class_register(&cros_class);
376 	if (ret) {
377 		pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
378 		return ret;
379 	}
380 
381 	ret = platform_driver_register(&cros_ec_dev_driver);
382 	if (ret) {
383 		pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
384 		class_unregister(&cros_class);
385 	}
386 	return ret;
387 }
388 
cros_ec_dev_exit(void)389 static void __exit cros_ec_dev_exit(void)
390 {
391 	platform_driver_unregister(&cros_ec_dev_driver);
392 	class_unregister(&cros_class);
393 }
394 
395 module_init(cros_ec_dev_init);
396 module_exit(cros_ec_dev_exit);
397 
398 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
399 MODULE_DESCRIPTION("ChromeOS Embedded Controller");
400 MODULE_VERSION("1.0");
401 MODULE_LICENSE("GPL");
402