xref: /linux/drivers/platform/x86/x86-android-tablets/core.c (revision dc850faa28ee0ac18e5e192526cdfa1da0b9d951)
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 
25 static struct platform_device *x86_android_tablet_device;
26 
27 int x86_android_tablet_get_gpiod(const char *chip, int pin, const char *con_id,
28 				 bool active_low, enum gpiod_flags dflags,
29 				 struct gpio_desc **desc)
30 {
31 	struct gpiod_lookup_table *lookup;
32 	struct gpio_desc *gpiod;
33 
34 	lookup = kzalloc(struct_size(lookup, table, 2), GFP_KERNEL);
35 	if (!lookup)
36 		return -ENOMEM;
37 
38 	lookup->dev_id = KBUILD_MODNAME;
39 	lookup->table[0].key = chip;
40 	lookup->table[0].chip_hwnum = pin;
41 	lookup->table[0].con_id = con_id;
42 	lookup->table[0].flags = active_low ? GPIO_ACTIVE_LOW : GPIO_ACTIVE_HIGH;
43 
44 	gpiod_add_lookup_table(lookup);
45 	gpiod = devm_gpiod_get(&x86_android_tablet_device->dev, con_id, dflags);
46 	gpiod_remove_lookup_table(lookup);
47 	kfree(lookup);
48 
49 	if (IS_ERR(gpiod)) {
50 		pr_err("error %ld getting GPIO %s %d\n", PTR_ERR(gpiod), chip, pin);
51 		return PTR_ERR(gpiod);
52 	}
53 
54 	if (desc)
55 		*desc = gpiod;
56 
57 	return 0;
58 }
59 
60 int x86_acpi_irq_helper_get(const struct x86_acpi_irq_data *data)
61 {
62 	struct irq_fwspec fwspec = { };
63 	struct irq_domain *domain;
64 	struct acpi_device *adev;
65 	struct gpio_desc *gpiod;
66 	unsigned int irq_type;
67 	acpi_handle handle;
68 	acpi_status status;
69 	int irq, ret;
70 
71 	switch (data->type) {
72 	case X86_ACPI_IRQ_TYPE_APIC:
73 		/*
74 		 * The DSDT may already reference the GSI in a device skipped by
75 		 * acpi_quirk_skip_i2c_client_enumeration(). Unregister the GSI
76 		 * to avoid EBUSY errors in this case.
77 		 */
78 		acpi_unregister_gsi(data->index);
79 		irq = acpi_register_gsi(NULL, data->index, data->trigger, data->polarity);
80 		if (irq < 0)
81 			pr_err("error %d getting APIC IRQ %d\n", irq, data->index);
82 
83 		return irq;
84 	case X86_ACPI_IRQ_TYPE_GPIOINT:
85 		/* Like acpi_dev_gpio_irq_get(), but without parsing ACPI resources */
86 		ret = x86_android_tablet_get_gpiod(data->chip, data->index, data->con_id,
87 						   false, GPIOD_ASIS, &gpiod);
88 		if (ret)
89 			return ret;
90 
91 		irq = gpiod_to_irq(gpiod);
92 		if (irq < 0) {
93 			pr_err("error %d getting IRQ %s %d\n", irq, data->chip, data->index);
94 			return irq;
95 		}
96 
97 		irq_type = acpi_dev_get_irq_type(data->trigger, data->polarity);
98 		if (irq_type != IRQ_TYPE_NONE && irq_type != irq_get_trigger_type(irq))
99 			irq_set_irq_type(irq, irq_type);
100 
101 		return irq;
102 	case X86_ACPI_IRQ_TYPE_PMIC:
103 		status = acpi_get_handle(NULL, data->chip, &handle);
104 		if (ACPI_FAILURE(status)) {
105 			pr_err("error could not get %s handle\n", data->chip);
106 			return -ENODEV;
107 		}
108 
109 		adev = acpi_fetch_acpi_dev(handle);
110 		if (!adev) {
111 			pr_err("error could not get %s adev\n", data->chip);
112 			return -ENODEV;
113 		}
114 
115 		fwspec.fwnode = acpi_fwnode_handle(adev);
116 		domain = irq_find_matching_fwspec(&fwspec, data->domain);
117 		if (!domain) {
118 			pr_err("error could not find IRQ domain for %s\n", data->chip);
119 			return -ENODEV;
120 		}
121 
122 		return irq_create_mapping(domain, data->index);
123 	default:
124 		return 0;
125 	}
126 }
127 
128 static int i2c_client_count;
129 static int pdev_count;
130 static int serdev_count;
131 static struct i2c_client **i2c_clients;
132 static struct platform_device **pdevs;
133 static struct serdev_device **serdevs;
134 static struct gpio_keys_button *buttons;
135 static struct gpiod_lookup_table * const *gpiod_lookup_tables;
136 static const struct software_node *bat_swnode;
137 static void (*exit_handler)(void);
138 
139 static __init int x86_instantiate_i2c_client(const struct x86_dev_info *dev_info,
140 					     int idx)
141 {
142 	const struct x86_i2c_client_info *client_info = &dev_info->i2c_client_info[idx];
143 	struct i2c_board_info board_info = client_info->board_info;
144 	struct i2c_adapter *adap;
145 	acpi_handle handle;
146 	acpi_status status;
147 
148 	board_info.irq = x86_acpi_irq_helper_get(&client_info->irq_data);
149 	if (board_info.irq < 0)
150 		return board_info.irq;
151 
152 	status = acpi_get_handle(NULL, client_info->adapter_path, &handle);
153 	if (ACPI_FAILURE(status)) {
154 		pr_err("Error could not get %s handle\n", client_info->adapter_path);
155 		return -ENODEV;
156 	}
157 
158 	adap = i2c_acpi_find_adapter_by_handle(handle);
159 	if (!adap) {
160 		pr_err("error could not get %s adapter\n", client_info->adapter_path);
161 		return -ENODEV;
162 	}
163 
164 	i2c_clients[idx] = i2c_new_client_device(adap, &board_info);
165 	put_device(&adap->dev);
166 	if (IS_ERR(i2c_clients[idx]))
167 		return dev_err_probe(&adap->dev, PTR_ERR(i2c_clients[idx]),
168 				      "creating I2C-client %d\n", idx);
169 
170 	return 0;
171 }
172 
173 static __init int x86_instantiate_serdev(const struct x86_serdev_info *info, int idx)
174 {
175 	struct acpi_device *ctrl_adev, *serdev_adev;
176 	struct serdev_device *serdev;
177 	struct device *ctrl_dev;
178 	int ret = -ENODEV;
179 
180 	ctrl_adev = acpi_dev_get_first_match_dev(info->ctrl_hid, info->ctrl_uid, -1);
181 	if (!ctrl_adev) {
182 		pr_err("error could not get %s/%s ctrl adev\n",
183 		       info->ctrl_hid, info->ctrl_uid);
184 		return -ENODEV;
185 	}
186 
187 	serdev_adev = acpi_dev_get_first_match_dev(info->serdev_hid, NULL, -1);
188 	if (!serdev_adev) {
189 		pr_err("error could not get %s serdev adev\n", info->serdev_hid);
190 		goto put_ctrl_adev;
191 	}
192 
193 	/* get_first_physical_node() returns a weak ref, no need to put() it */
194 	ctrl_dev = acpi_get_first_physical_node(ctrl_adev);
195 	if (!ctrl_dev)	{
196 		pr_err("error could not get %s/%s ctrl physical dev\n",
197 		       info->ctrl_hid, info->ctrl_uid);
198 		goto put_serdev_adev;
199 	}
200 
201 	/* ctrl_dev now points to the controller's parent, get the controller */
202 	ctrl_dev = device_find_child_by_name(ctrl_dev, info->ctrl_devname);
203 	if (!ctrl_dev) {
204 		pr_err("error could not get %s/%s %s ctrl dev\n",
205 		       info->ctrl_hid, info->ctrl_uid, info->ctrl_devname);
206 		goto put_serdev_adev;
207 	}
208 
209 	serdev = serdev_device_alloc(to_serdev_controller(ctrl_dev));
210 	if (!serdev) {
211 		ret = -ENOMEM;
212 		goto put_serdev_adev;
213 	}
214 
215 	ACPI_COMPANION_SET(&serdev->dev, serdev_adev);
216 	acpi_device_set_enumerated(serdev_adev);
217 
218 	ret = serdev_device_add(serdev);
219 	if (ret) {
220 		dev_err(&serdev->dev, "error %d adding serdev\n", ret);
221 		serdev_device_put(serdev);
222 		goto put_serdev_adev;
223 	}
224 
225 	serdevs[idx] = serdev;
226 
227 put_serdev_adev:
228 	acpi_dev_put(serdev_adev);
229 put_ctrl_adev:
230 	acpi_dev_put(ctrl_adev);
231 	return ret;
232 }
233 
234 static void x86_android_tablet_remove(struct platform_device *pdev)
235 {
236 	int i;
237 
238 	for (i = 0; i < serdev_count; i++) {
239 		if (serdevs[i])
240 			serdev_device_remove(serdevs[i]);
241 	}
242 
243 	kfree(serdevs);
244 
245 	for (i = 0; i < pdev_count; i++)
246 		platform_device_unregister(pdevs[i]);
247 
248 	kfree(pdevs);
249 	kfree(buttons);
250 
251 	for (i = 0; i < i2c_client_count; i++)
252 		i2c_unregister_device(i2c_clients[i]);
253 
254 	kfree(i2c_clients);
255 
256 	if (exit_handler)
257 		exit_handler();
258 
259 	for (i = 0; gpiod_lookup_tables && gpiod_lookup_tables[i]; i++)
260 		gpiod_remove_lookup_table(gpiod_lookup_tables[i]);
261 
262 	software_node_unregister(bat_swnode);
263 }
264 
265 static __init int x86_android_tablet_probe(struct platform_device *pdev)
266 {
267 	const struct x86_dev_info *dev_info;
268 	const struct dmi_system_id *id;
269 	int i, ret = 0;
270 
271 	id = dmi_first_match(x86_android_tablet_ids);
272 	if (!id)
273 		return -ENODEV;
274 
275 	dev_info = id->driver_data;
276 	/* Allow x86_android_tablet_device use before probe() exits */
277 	x86_android_tablet_device = pdev;
278 
279 	/*
280 	 * Since this runs from module_init() it cannot use -EPROBE_DEFER,
281 	 * instead pre-load any modules which are listed as requirements.
282 	 */
283 	for (i = 0; dev_info->modules && dev_info->modules[i]; i++)
284 		request_module(dev_info->modules[i]);
285 
286 	bat_swnode = dev_info->bat_swnode;
287 	if (bat_swnode) {
288 		ret = software_node_register(bat_swnode);
289 		if (ret)
290 			return ret;
291 	}
292 
293 	gpiod_lookup_tables = dev_info->gpiod_lookup_tables;
294 	for (i = 0; gpiod_lookup_tables && gpiod_lookup_tables[i]; i++)
295 		gpiod_add_lookup_table(gpiod_lookup_tables[i]);
296 
297 	if (dev_info->init) {
298 		ret = dev_info->init();
299 		if (ret < 0) {
300 			x86_android_tablet_remove(pdev);
301 			return ret;
302 		}
303 		exit_handler = dev_info->exit;
304 	}
305 
306 	i2c_clients = kcalloc(dev_info->i2c_client_count, sizeof(*i2c_clients), GFP_KERNEL);
307 	if (!i2c_clients) {
308 		x86_android_tablet_remove(pdev);
309 		return -ENOMEM;
310 	}
311 
312 	i2c_client_count = dev_info->i2c_client_count;
313 	for (i = 0; i < i2c_client_count; i++) {
314 		ret = x86_instantiate_i2c_client(dev_info, i);
315 		if (ret < 0) {
316 			x86_android_tablet_remove(pdev);
317 			return ret;
318 		}
319 	}
320 
321 	/* + 1 to make space for (optional) gpio_keys_button pdev */
322 	pdevs = kcalloc(dev_info->pdev_count + 1, sizeof(*pdevs), GFP_KERNEL);
323 	if (!pdevs) {
324 		x86_android_tablet_remove(pdev);
325 		return -ENOMEM;
326 	}
327 
328 	pdev_count = dev_info->pdev_count;
329 	for (i = 0; i < pdev_count; i++) {
330 		pdevs[i] = platform_device_register_full(&dev_info->pdev_info[i]);
331 		if (IS_ERR(pdevs[i])) {
332 			x86_android_tablet_remove(pdev);
333 			return PTR_ERR(pdevs[i]);
334 		}
335 	}
336 
337 	serdevs = kcalloc(dev_info->serdev_count, sizeof(*serdevs), GFP_KERNEL);
338 	if (!serdevs) {
339 		x86_android_tablet_remove(pdev);
340 		return -ENOMEM;
341 	}
342 
343 	serdev_count = dev_info->serdev_count;
344 	for (i = 0; i < serdev_count; i++) {
345 		ret = x86_instantiate_serdev(&dev_info->serdev_info[i], i);
346 		if (ret < 0) {
347 			x86_android_tablet_remove(pdev);
348 			return ret;
349 		}
350 	}
351 
352 	if (dev_info->gpio_button_count) {
353 		struct gpio_keys_platform_data pdata = { };
354 		struct gpio_desc *gpiod;
355 
356 		buttons = kcalloc(dev_info->gpio_button_count, sizeof(*buttons), GFP_KERNEL);
357 		if (!buttons) {
358 			x86_android_tablet_remove(pdev);
359 			return -ENOMEM;
360 		}
361 
362 		for (i = 0; i < dev_info->gpio_button_count; i++) {
363 			ret = x86_android_tablet_get_gpiod(dev_info->gpio_button[i].chip,
364 							   dev_info->gpio_button[i].pin,
365 							   dev_info->gpio_button[i].button.desc,
366 							   false, GPIOD_IN, &gpiod);
367 			if (ret < 0) {
368 				x86_android_tablet_remove(pdev);
369 				return ret;
370 			}
371 
372 			buttons[i] = dev_info->gpio_button[i].button;
373 			buttons[i].gpio = desc_to_gpio(gpiod);
374 			/* Release gpiod so that gpio-keys can request it */
375 			devm_gpiod_put(&x86_android_tablet_device->dev, gpiod);
376 		}
377 
378 		pdata.buttons = buttons;
379 		pdata.nbuttons = dev_info->gpio_button_count;
380 
381 		pdevs[pdev_count] = platform_device_register_data(&pdev->dev, "gpio-keys",
382 								  PLATFORM_DEVID_AUTO,
383 								  &pdata, sizeof(pdata));
384 		if (IS_ERR(pdevs[pdev_count])) {
385 			x86_android_tablet_remove(pdev);
386 			return PTR_ERR(pdevs[pdev_count]);
387 		}
388 		pdev_count++;
389 	}
390 
391 	return 0;
392 }
393 
394 static struct platform_driver x86_android_tablet_driver = {
395 	.driver = {
396 		.name = KBUILD_MODNAME,
397 	},
398 	.remove_new = x86_android_tablet_remove,
399 };
400 
401 static int __init x86_android_tablet_init(void)
402 {
403 	x86_android_tablet_device = platform_create_bundle(&x86_android_tablet_driver,
404 						   x86_android_tablet_probe,
405 						   NULL, 0, NULL, 0);
406 
407 	return PTR_ERR_OR_ZERO(x86_android_tablet_device);
408 }
409 module_init(x86_android_tablet_init);
410 
411 static void __exit x86_android_tablet_exit(void)
412 {
413 	platform_device_unregister(x86_android_tablet_device);
414 	platform_driver_unregister(&x86_android_tablet_driver);
415 }
416 module_exit(x86_android_tablet_exit);
417 
418 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
419 MODULE_DESCRIPTION("X86 Android tablets DSDT fixups driver");
420 MODULE_LICENSE("GPL");
421