xref: /linux/drivers/platform/x86/x86-android-tablets/core.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * DMI based code to deal with broken DSDTs on X86 tablets which ship with
4  * Android as (part of) the factory image. The factory kernels shipped on these
5  * devices typically have a bunch of things hardcoded, rather than specified
6  * in their DSDT.
7  *
8  * Copyright (C) 2021-2023 Hans de Goede <hdegoede@redhat.com>
9  */
10 
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/acpi.h>
14 #include <linux/dmi.h>
15 #include <linux/gpio/consumer.h>
16 #include <linux/gpio/machine.h>
17 #include <linux/irq.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/serdev.h>
21 #include <linux/string.h>
22 
23 #include "x86-android-tablets.h"
24 #include "../serdev_helpers.h"
25 
26 static struct platform_device *x86_android_tablet_device;
27 
28 /*
29  * This helper allows getting a GPIO descriptor *before* the actual device
30  * consuming it has been instantiated. This function MUST only be used to
31  * handle this special case such as, e.g.:
32  *
33  * 1. Getting an IRQ from a GPIO for i2c_board_info.irq which is passed to
34  * i2c_client_new() to instantiate i2c_client-s; or
35  * 2. Calling desc_to_gpio() to get an old style GPIO number for gpio-keys
36  * platform_data which still uses old style GPIO numbers.
37  *
38  * Since the consuming device has not been instantiated yet a dynamic lookup
39  * is generated using the special x86_android_tablet device for dev_id.
40  *
41  * For normal GPIO lookups a standard static struct gpiod_lookup_table MUST be used.
42  */
43 int x86_android_tablet_get_gpiod(const char *chip, int pin, const char *con_id,
44 				 bool active_low, enum gpiod_flags dflags,
45 				 struct gpio_desc **desc)
46 {
47 	struct gpiod_lookup_table *lookup;
48 	struct gpio_desc *gpiod;
49 
50 	lookup = kzalloc(struct_size(lookup, table, 2), GFP_KERNEL);
51 	if (!lookup)
52 		return -ENOMEM;
53 
54 	lookup->dev_id = KBUILD_MODNAME;
55 	lookup->table[0] =
56 		GPIO_LOOKUP(chip, pin, con_id, active_low ? GPIO_ACTIVE_LOW : GPIO_ACTIVE_HIGH);
57 
58 	gpiod_add_lookup_table(lookup);
59 	gpiod = devm_gpiod_get(&x86_android_tablet_device->dev, con_id, dflags);
60 	gpiod_remove_lookup_table(lookup);
61 	kfree(lookup);
62 
63 	if (IS_ERR(gpiod)) {
64 		pr_err("error %ld getting GPIO %s %d\n", PTR_ERR(gpiod), chip, pin);
65 		return PTR_ERR(gpiod);
66 	}
67 
68 	if (desc)
69 		*desc = gpiod;
70 
71 	return 0;
72 }
73 
74 int x86_acpi_irq_helper_get(const struct x86_acpi_irq_data *data)
75 {
76 	struct irq_fwspec fwspec = { };
77 	struct irq_domain *domain;
78 	struct acpi_device *adev;
79 	struct gpio_desc *gpiod;
80 	unsigned int irq_type;
81 	acpi_handle handle;
82 	acpi_status status;
83 	int irq, ret;
84 
85 	switch (data->type) {
86 	case X86_ACPI_IRQ_TYPE_APIC:
87 		/*
88 		 * The DSDT may already reference the GSI in a device skipped by
89 		 * acpi_quirk_skip_i2c_client_enumeration(). Unregister the GSI
90 		 * to avoid -EBUSY errors in this case.
91 		 */
92 		acpi_unregister_gsi(data->index);
93 		irq = acpi_register_gsi(NULL, data->index, data->trigger, data->polarity);
94 		if (irq < 0)
95 			pr_err("error %d getting APIC IRQ %d\n", irq, data->index);
96 
97 		return irq;
98 	case X86_ACPI_IRQ_TYPE_GPIOINT:
99 		/* Like acpi_dev_gpio_irq_get(), but without parsing ACPI resources */
100 		ret = x86_android_tablet_get_gpiod(data->chip, data->index, data->con_id,
101 						   false, GPIOD_ASIS, &gpiod);
102 		if (ret)
103 			return ret;
104 
105 		irq = gpiod_to_irq(gpiod);
106 		if (irq < 0) {
107 			pr_err("error %d getting IRQ %s %d\n", irq, data->chip, data->index);
108 			return irq;
109 		}
110 
111 		irq_type = acpi_dev_get_irq_type(data->trigger, data->polarity);
112 		if (irq_type != IRQ_TYPE_NONE && irq_type != irq_get_trigger_type(irq))
113 			irq_set_irq_type(irq, irq_type);
114 
115 		if (data->free_gpio)
116 			devm_gpiod_put(&x86_android_tablet_device->dev, gpiod);
117 
118 		return irq;
119 	case X86_ACPI_IRQ_TYPE_PMIC:
120 		status = acpi_get_handle(NULL, data->chip, &handle);
121 		if (ACPI_FAILURE(status)) {
122 			pr_err("error could not get %s handle\n", data->chip);
123 			return -ENODEV;
124 		}
125 
126 		adev = acpi_fetch_acpi_dev(handle);
127 		if (!adev) {
128 			pr_err("error could not get %s adev\n", data->chip);
129 			return -ENODEV;
130 		}
131 
132 		fwspec.fwnode = acpi_fwnode_handle(adev);
133 		domain = irq_find_matching_fwspec(&fwspec, data->domain);
134 		if (!domain) {
135 			pr_err("error could not find IRQ domain for %s\n", data->chip);
136 			return -ENODEV;
137 		}
138 
139 		return irq_create_mapping(domain, data->index);
140 	default:
141 		return 0;
142 	}
143 }
144 
145 static int i2c_client_count;
146 static int spi_dev_count;
147 static int pdev_count;
148 static int serdev_count;
149 static struct i2c_client **i2c_clients;
150 static struct spi_device **spi_devs;
151 static struct platform_device **pdevs;
152 static struct serdev_device **serdevs;
153 static struct gpio_keys_button *buttons;
154 static struct gpiod_lookup_table * const *gpiod_lookup_tables;
155 static const struct software_node *bat_swnode;
156 static void (*exit_handler)(void);
157 
158 static __init int x86_instantiate_i2c_client(const struct x86_dev_info *dev_info,
159 					     int idx)
160 {
161 	const struct x86_i2c_client_info *client_info = &dev_info->i2c_client_info[idx];
162 	struct i2c_board_info board_info = client_info->board_info;
163 	struct i2c_adapter *adap;
164 	acpi_handle handle;
165 	acpi_status status;
166 
167 	board_info.irq = x86_acpi_irq_helper_get(&client_info->irq_data);
168 	if (board_info.irq < 0)
169 		return board_info.irq;
170 
171 	status = acpi_get_handle(NULL, client_info->adapter_path, &handle);
172 	if (ACPI_FAILURE(status)) {
173 		pr_err("Error could not get %s handle\n", client_info->adapter_path);
174 		return -ENODEV;
175 	}
176 
177 	adap = i2c_acpi_find_adapter_by_handle(handle);
178 	if (!adap) {
179 		pr_err("error could not get %s adapter\n", client_info->adapter_path);
180 		return -ENODEV;
181 	}
182 
183 	i2c_clients[idx] = i2c_new_client_device(adap, &board_info);
184 	put_device(&adap->dev);
185 	if (IS_ERR(i2c_clients[idx]))
186 		return dev_err_probe(&adap->dev, PTR_ERR(i2c_clients[idx]),
187 				      "creating I2C-client %d\n", idx);
188 
189 	return 0;
190 }
191 
192 static __init int x86_instantiate_spi_dev(const struct x86_dev_info *dev_info, int idx)
193 {
194 	const struct x86_spi_dev_info *spi_dev_info = &dev_info->spi_dev_info[idx];
195 	struct spi_board_info board_info = spi_dev_info->board_info;
196 	struct spi_controller *controller;
197 	struct acpi_device *adev;
198 	acpi_handle handle;
199 	acpi_status status;
200 
201 	board_info.irq = x86_acpi_irq_helper_get(&spi_dev_info->irq_data);
202 	if (board_info.irq < 0)
203 		return board_info.irq;
204 
205 	status = acpi_get_handle(NULL, spi_dev_info->ctrl_path, &handle);
206 	if (ACPI_FAILURE(status)) {
207 		pr_err("Error could not get %s handle\n", spi_dev_info->ctrl_path);
208 		return -ENODEV;
209 	}
210 
211 	adev = acpi_fetch_acpi_dev(handle);
212 	if (!adev) {
213 		pr_err("Error could not get adev for %s\n", spi_dev_info->ctrl_path);
214 		return -ENODEV;
215 	}
216 
217 	controller = acpi_spi_find_controller_by_adev(adev);
218 	if (!controller) {
219 		pr_err("Error could not get SPI controller for %s\n", spi_dev_info->ctrl_path);
220 		return -ENODEV;
221 	}
222 
223 	spi_devs[idx] = spi_new_device(controller, &board_info);
224 	put_device(&controller->dev);
225 	if (!spi_devs[idx])
226 		return dev_err_probe(&controller->dev, -ENOMEM,
227 				     "creating SPI-device %d\n", idx);
228 
229 	return 0;
230 }
231 
232 static __init int x86_instantiate_serdev(const struct x86_serdev_info *info, int idx)
233 {
234 	struct acpi_device *serdev_adev;
235 	struct serdev_device *serdev;
236 	struct device *ctrl_dev;
237 	int ret = -ENODEV;
238 
239 	ctrl_dev = get_serdev_controller(info->ctrl_hid, info->ctrl_uid, 0,
240 					 info->ctrl_devname);
241 	if (IS_ERR(ctrl_dev))
242 		return PTR_ERR(ctrl_dev);
243 
244 	serdev_adev = acpi_dev_get_first_match_dev(info->serdev_hid, NULL, -1);
245 	if (!serdev_adev) {
246 		pr_err("error could not get %s serdev adev\n", info->serdev_hid);
247 		goto put_ctrl_dev;
248 	}
249 
250 	serdev = serdev_device_alloc(to_serdev_controller(ctrl_dev));
251 	if (!serdev) {
252 		ret = -ENOMEM;
253 		goto put_serdev_adev;
254 	}
255 
256 	ACPI_COMPANION_SET(&serdev->dev, serdev_adev);
257 	acpi_device_set_enumerated(serdev_adev);
258 
259 	ret = serdev_device_add(serdev);
260 	if (ret) {
261 		dev_err(&serdev->dev, "error %d adding serdev\n", ret);
262 		serdev_device_put(serdev);
263 		goto put_serdev_adev;
264 	}
265 
266 	serdevs[idx] = serdev;
267 
268 put_serdev_adev:
269 	acpi_dev_put(serdev_adev);
270 put_ctrl_dev:
271 	put_device(ctrl_dev);
272 	return ret;
273 }
274 
275 static void x86_android_tablet_remove(struct platform_device *pdev)
276 {
277 	int i;
278 
279 	for (i = serdev_count - 1; i >= 0; i--) {
280 		if (serdevs[i])
281 			serdev_device_remove(serdevs[i]);
282 	}
283 
284 	kfree(serdevs);
285 
286 	for (i = pdev_count - 1; i >= 0; i--)
287 		platform_device_unregister(pdevs[i]);
288 
289 	kfree(pdevs);
290 	kfree(buttons);
291 
292 	for (i = spi_dev_count - 1; i >= 0; i--)
293 		spi_unregister_device(spi_devs[i]);
294 
295 	kfree(spi_devs);
296 
297 	for (i = i2c_client_count - 1; i >= 0; i--)
298 		i2c_unregister_device(i2c_clients[i]);
299 
300 	kfree(i2c_clients);
301 
302 	if (exit_handler)
303 		exit_handler();
304 
305 	for (i = 0; gpiod_lookup_tables && gpiod_lookup_tables[i]; i++)
306 		gpiod_remove_lookup_table(gpiod_lookup_tables[i]);
307 
308 	software_node_unregister(bat_swnode);
309 }
310 
311 static __init int x86_android_tablet_probe(struct platform_device *pdev)
312 {
313 	const struct x86_dev_info *dev_info;
314 	const struct dmi_system_id *id;
315 	int i, ret = 0;
316 
317 	id = dmi_first_match(x86_android_tablet_ids);
318 	if (!id)
319 		return -ENODEV;
320 
321 	dev_info = id->driver_data;
322 	/* Allow x86_android_tablet_device use before probe() exits */
323 	x86_android_tablet_device = pdev;
324 
325 	/*
326 	 * Since this runs from module_init() it cannot use -EPROBE_DEFER,
327 	 * instead pre-load any modules which are listed as requirements.
328 	 */
329 	for (i = 0; dev_info->modules && dev_info->modules[i]; i++)
330 		request_module(dev_info->modules[i]);
331 
332 	bat_swnode = dev_info->bat_swnode;
333 	if (bat_swnode) {
334 		ret = software_node_register(bat_swnode);
335 		if (ret)
336 			return ret;
337 	}
338 
339 	gpiod_lookup_tables = dev_info->gpiod_lookup_tables;
340 	for (i = 0; gpiod_lookup_tables && gpiod_lookup_tables[i]; i++)
341 		gpiod_add_lookup_table(gpiod_lookup_tables[i]);
342 
343 	if (dev_info->init) {
344 		ret = dev_info->init(&pdev->dev);
345 		if (ret < 0) {
346 			x86_android_tablet_remove(pdev);
347 			return ret;
348 		}
349 		exit_handler = dev_info->exit;
350 	}
351 
352 	i2c_clients = kcalloc(dev_info->i2c_client_count, sizeof(*i2c_clients), GFP_KERNEL);
353 	if (!i2c_clients) {
354 		x86_android_tablet_remove(pdev);
355 		return -ENOMEM;
356 	}
357 
358 	i2c_client_count = dev_info->i2c_client_count;
359 	for (i = 0; i < i2c_client_count; i++) {
360 		ret = x86_instantiate_i2c_client(dev_info, i);
361 		if (ret < 0) {
362 			x86_android_tablet_remove(pdev);
363 			return ret;
364 		}
365 	}
366 
367 	spi_devs = kcalloc(dev_info->spi_dev_count, sizeof(*spi_devs), GFP_KERNEL);
368 	if (!spi_devs) {
369 		x86_android_tablet_remove(pdev);
370 		return -ENOMEM;
371 	}
372 
373 	spi_dev_count = dev_info->spi_dev_count;
374 	for (i = 0; i < spi_dev_count; i++) {
375 		ret = x86_instantiate_spi_dev(dev_info, i);
376 		if (ret < 0) {
377 			x86_android_tablet_remove(pdev);
378 			return ret;
379 		}
380 	}
381 
382 	/* + 1 to make space for the (optional) gpio_keys_button platform device */
383 	pdevs = kcalloc(dev_info->pdev_count + 1, sizeof(*pdevs), GFP_KERNEL);
384 	if (!pdevs) {
385 		x86_android_tablet_remove(pdev);
386 		return -ENOMEM;
387 	}
388 
389 	pdev_count = dev_info->pdev_count;
390 	for (i = 0; i < pdev_count; i++) {
391 		pdevs[i] = platform_device_register_full(&dev_info->pdev_info[i]);
392 		if (IS_ERR(pdevs[i])) {
393 			ret = PTR_ERR(pdevs[i]);
394 			x86_android_tablet_remove(pdev);
395 			return ret;
396 		}
397 	}
398 
399 	serdevs = kcalloc(dev_info->serdev_count, sizeof(*serdevs), GFP_KERNEL);
400 	if (!serdevs) {
401 		x86_android_tablet_remove(pdev);
402 		return -ENOMEM;
403 	}
404 
405 	serdev_count = dev_info->serdev_count;
406 	for (i = 0; i < serdev_count; i++) {
407 		ret = x86_instantiate_serdev(&dev_info->serdev_info[i], i);
408 		if (ret < 0) {
409 			x86_android_tablet_remove(pdev);
410 			return ret;
411 		}
412 	}
413 
414 	if (dev_info->gpio_button_count) {
415 		struct gpio_keys_platform_data pdata = { };
416 		struct gpio_desc *gpiod;
417 
418 		buttons = kcalloc(dev_info->gpio_button_count, sizeof(*buttons), GFP_KERNEL);
419 		if (!buttons) {
420 			x86_android_tablet_remove(pdev);
421 			return -ENOMEM;
422 		}
423 
424 		for (i = 0; i < dev_info->gpio_button_count; i++) {
425 			ret = x86_android_tablet_get_gpiod(dev_info->gpio_button[i].chip,
426 							   dev_info->gpio_button[i].pin,
427 							   dev_info->gpio_button[i].button.desc,
428 							   false, GPIOD_IN, &gpiod);
429 			if (ret < 0) {
430 				x86_android_tablet_remove(pdev);
431 				return ret;
432 			}
433 
434 			buttons[i] = dev_info->gpio_button[i].button;
435 			buttons[i].gpio = desc_to_gpio(gpiod);
436 			/* Release GPIO descriptor so that gpio-keys can request it */
437 			devm_gpiod_put(&x86_android_tablet_device->dev, gpiod);
438 		}
439 
440 		pdata.buttons = buttons;
441 		pdata.nbuttons = dev_info->gpio_button_count;
442 
443 		pdevs[pdev_count] = platform_device_register_data(&pdev->dev, "gpio-keys",
444 								  PLATFORM_DEVID_AUTO,
445 								  &pdata, sizeof(pdata));
446 		if (IS_ERR(pdevs[pdev_count])) {
447 			ret = PTR_ERR(pdevs[pdev_count]);
448 			x86_android_tablet_remove(pdev);
449 			return ret;
450 		}
451 		pdev_count++;
452 	}
453 
454 	return 0;
455 }
456 
457 static struct platform_driver x86_android_tablet_driver = {
458 	.driver = {
459 		.name = KBUILD_MODNAME,
460 	},
461 	.remove_new = x86_android_tablet_remove,
462 };
463 
464 static int __init x86_android_tablet_init(void)
465 {
466 	x86_android_tablet_device = platform_create_bundle(&x86_android_tablet_driver,
467 						   x86_android_tablet_probe,
468 						   NULL, 0, NULL, 0);
469 
470 	return PTR_ERR_OR_ZERO(x86_android_tablet_device);
471 }
472 module_init(x86_android_tablet_init);
473 
474 static void __exit x86_android_tablet_exit(void)
475 {
476 	platform_device_unregister(x86_android_tablet_device);
477 	platform_driver_unregister(&x86_android_tablet_driver);
478 }
479 module_exit(x86_android_tablet_exit);
480 
481 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
482 MODULE_DESCRIPTION("X86 Android tablets DSDT fixups driver");
483 MODULE_LICENSE("GPL");
484