xref: /openbmc/linux/drivers/acpi/acpi_lpss.c (revision c67e8ec0)
1 /*
2  * ACPI support for Intel Lynxpoint LPSS.
3  *
4  * Copyright (C) 2013, Intel Corporation
5  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
6  *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/acpi.h>
14 #include <linux/clkdev.h>
15 #include <linux/clk-provider.h>
16 #include <linux/err.h>
17 #include <linux/io.h>
18 #include <linux/mutex.h>
19 #include <linux/pci.h>
20 #include <linux/platform_device.h>
21 #include <linux/platform_data/clk-lpss.h>
22 #include <linux/platform_data/x86/pmc_atom.h>
23 #include <linux/pm_domain.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/pwm.h>
26 #include <linux/suspend.h>
27 #include <linux/delay.h>
28 
29 #include "internal.h"
30 
31 ACPI_MODULE_NAME("acpi_lpss");
32 
33 #ifdef CONFIG_X86_INTEL_LPSS
34 
35 #include <asm/cpu_device_id.h>
36 #include <asm/intel-family.h>
37 #include <asm/iosf_mbi.h>
38 
39 #define LPSS_ADDR(desc) ((unsigned long)&desc)
40 
41 #define LPSS_CLK_SIZE	0x04
42 #define LPSS_LTR_SIZE	0x18
43 
44 /* Offsets relative to LPSS_PRIVATE_OFFSET */
45 #define LPSS_CLK_DIVIDER_DEF_MASK	(BIT(1) | BIT(16))
46 #define LPSS_RESETS			0x04
47 #define LPSS_RESETS_RESET_FUNC		BIT(0)
48 #define LPSS_RESETS_RESET_APB		BIT(1)
49 #define LPSS_GENERAL			0x08
50 #define LPSS_GENERAL_LTR_MODE_SW	BIT(2)
51 #define LPSS_GENERAL_UART_RTS_OVRD	BIT(3)
52 #define LPSS_SW_LTR			0x10
53 #define LPSS_AUTO_LTR			0x14
54 #define LPSS_LTR_SNOOP_REQ		BIT(15)
55 #define LPSS_LTR_SNOOP_MASK		0x0000FFFF
56 #define LPSS_LTR_SNOOP_LAT_1US		0x800
57 #define LPSS_LTR_SNOOP_LAT_32US		0xC00
58 #define LPSS_LTR_SNOOP_LAT_SHIFT	5
59 #define LPSS_LTR_SNOOP_LAT_CUTOFF	3000
60 #define LPSS_LTR_MAX_VAL		0x3FF
61 #define LPSS_TX_INT			0x20
62 #define LPSS_TX_INT_MASK		BIT(1)
63 
64 #define LPSS_PRV_REG_COUNT		9
65 
66 /* LPSS Flags */
67 #define LPSS_CLK			BIT(0)
68 #define LPSS_CLK_GATE			BIT(1)
69 #define LPSS_CLK_DIVIDER		BIT(2)
70 #define LPSS_LTR			BIT(3)
71 #define LPSS_SAVE_CTX			BIT(4)
72 #define LPSS_NO_D3_DELAY		BIT(5)
73 
74 /* Crystal Cove PMIC shares same ACPI ID between different platforms */
75 #define BYT_CRC_HRV			2
76 #define CHT_CRC_HRV			3
77 
78 struct lpss_private_data;
79 
80 struct lpss_device_desc {
81 	unsigned int flags;
82 	const char *clk_con_id;
83 	unsigned int prv_offset;
84 	size_t prv_size_override;
85 	struct property_entry *properties;
86 	void (*setup)(struct lpss_private_data *pdata);
87 	bool resume_from_noirq;
88 };
89 
90 static const struct lpss_device_desc lpss_dma_desc = {
91 	.flags = LPSS_CLK,
92 };
93 
94 struct lpss_private_data {
95 	struct acpi_device *adev;
96 	void __iomem *mmio_base;
97 	resource_size_t mmio_size;
98 	unsigned int fixed_clk_rate;
99 	struct clk *clk;
100 	const struct lpss_device_desc *dev_desc;
101 	u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
102 };
103 
104 /* Devices which need to be in D3 before lpss_iosf_enter_d3_state() proceeds */
105 static u32 pmc_atom_d3_mask = 0xfe000ffe;
106 
107 /* LPSS run time quirks */
108 static unsigned int lpss_quirks;
109 
110 /*
111  * LPSS_QUIRK_ALWAYS_POWER_ON: override power state for LPSS DMA device.
112  *
113  * The LPSS DMA controller has neither _PS0 nor _PS3 method. Moreover
114  * it can be powered off automatically whenever the last LPSS device goes down.
115  * In case of no power any access to the DMA controller will hang the system.
116  * The behaviour is reproduced on some HP laptops based on Intel BayTrail as
117  * well as on ASuS T100TA transformer.
118  *
119  * This quirk overrides power state of entire LPSS island to keep DMA powered
120  * on whenever we have at least one other device in use.
121  */
122 #define LPSS_QUIRK_ALWAYS_POWER_ON	BIT(0)
123 
124 /* UART Component Parameter Register */
125 #define LPSS_UART_CPR			0xF4
126 #define LPSS_UART_CPR_AFCE		BIT(4)
127 
128 static void lpss_uart_setup(struct lpss_private_data *pdata)
129 {
130 	unsigned int offset;
131 	u32 val;
132 
133 	offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
134 	val = readl(pdata->mmio_base + offset);
135 	writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
136 
137 	val = readl(pdata->mmio_base + LPSS_UART_CPR);
138 	if (!(val & LPSS_UART_CPR_AFCE)) {
139 		offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
140 		val = readl(pdata->mmio_base + offset);
141 		val |= LPSS_GENERAL_UART_RTS_OVRD;
142 		writel(val, pdata->mmio_base + offset);
143 	}
144 }
145 
146 static void lpss_deassert_reset(struct lpss_private_data *pdata)
147 {
148 	unsigned int offset;
149 	u32 val;
150 
151 	offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
152 	val = readl(pdata->mmio_base + offset);
153 	val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
154 	writel(val, pdata->mmio_base + offset);
155 }
156 
157 /*
158  * BYT PWM used for backlight control by the i915 driver on systems without
159  * the Crystal Cove PMIC.
160  */
161 static struct pwm_lookup byt_pwm_lookup[] = {
162 	PWM_LOOKUP_WITH_MODULE("80860F09:00", 0, "0000:00:02.0",
163 			       "pwm_backlight", 0, PWM_POLARITY_NORMAL,
164 			       "pwm-lpss-platform"),
165 };
166 
167 static void byt_pwm_setup(struct lpss_private_data *pdata)
168 {
169 	struct acpi_device *adev = pdata->adev;
170 
171 	/* Only call pwm_add_table for the first PWM controller */
172 	if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
173 		return;
174 
175 	if (!acpi_dev_present("INT33FD", NULL, BYT_CRC_HRV))
176 		pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup));
177 }
178 
179 #define LPSS_I2C_ENABLE			0x6c
180 
181 static void byt_i2c_setup(struct lpss_private_data *pdata)
182 {
183 	const char *uid_str = acpi_device_uid(pdata->adev);
184 	acpi_handle handle = pdata->adev->handle;
185 	unsigned long long shared_host = 0;
186 	acpi_status status;
187 	long uid = 0;
188 
189 	/* Expected to always be true, but better safe then sorry */
190 	if (uid_str)
191 		uid = simple_strtol(uid_str, NULL, 10);
192 
193 	/* Detect I2C bus shared with PUNIT and ignore its d3 status */
194 	status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
195 	if (ACPI_SUCCESS(status) && shared_host && uid)
196 		pmc_atom_d3_mask &= ~(BIT_LPSS2_F1_I2C1 << (uid - 1));
197 
198 	lpss_deassert_reset(pdata);
199 
200 	if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
201 		pdata->fixed_clk_rate = 133000000;
202 
203 	writel(0, pdata->mmio_base + LPSS_I2C_ENABLE);
204 }
205 
206 /* BSW PWM used for backlight control by the i915 driver */
207 static struct pwm_lookup bsw_pwm_lookup[] = {
208 	PWM_LOOKUP_WITH_MODULE("80862288:00", 0, "0000:00:02.0",
209 			       "pwm_backlight", 0, PWM_POLARITY_NORMAL,
210 			       "pwm-lpss-platform"),
211 };
212 
213 static void bsw_pwm_setup(struct lpss_private_data *pdata)
214 {
215 	struct acpi_device *adev = pdata->adev;
216 
217 	/* Only call pwm_add_table for the first PWM controller */
218 	if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
219 		return;
220 
221 	pwm_add_table(bsw_pwm_lookup, ARRAY_SIZE(bsw_pwm_lookup));
222 }
223 
224 static const struct lpss_device_desc lpt_dev_desc = {
225 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
226 	.prv_offset = 0x800,
227 };
228 
229 static const struct lpss_device_desc lpt_i2c_dev_desc = {
230 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR,
231 	.prv_offset = 0x800,
232 };
233 
234 static struct property_entry uart_properties[] = {
235 	PROPERTY_ENTRY_U32("reg-io-width", 4),
236 	PROPERTY_ENTRY_U32("reg-shift", 2),
237 	PROPERTY_ENTRY_BOOL("snps,uart-16550-compatible"),
238 	{ },
239 };
240 
241 static const struct lpss_device_desc lpt_uart_dev_desc = {
242 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
243 	.clk_con_id = "baudclk",
244 	.prv_offset = 0x800,
245 	.setup = lpss_uart_setup,
246 	.properties = uart_properties,
247 };
248 
249 static const struct lpss_device_desc lpt_sdio_dev_desc = {
250 	.flags = LPSS_LTR,
251 	.prv_offset = 0x1000,
252 	.prv_size_override = 0x1018,
253 };
254 
255 static const struct lpss_device_desc byt_pwm_dev_desc = {
256 	.flags = LPSS_SAVE_CTX,
257 	.prv_offset = 0x800,
258 	.setup = byt_pwm_setup,
259 };
260 
261 static const struct lpss_device_desc bsw_pwm_dev_desc = {
262 	.flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
263 	.prv_offset = 0x800,
264 	.setup = bsw_pwm_setup,
265 };
266 
267 static const struct lpss_device_desc byt_uart_dev_desc = {
268 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
269 	.clk_con_id = "baudclk",
270 	.prv_offset = 0x800,
271 	.setup = lpss_uart_setup,
272 	.properties = uart_properties,
273 };
274 
275 static const struct lpss_device_desc bsw_uart_dev_desc = {
276 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
277 			| LPSS_NO_D3_DELAY,
278 	.clk_con_id = "baudclk",
279 	.prv_offset = 0x800,
280 	.setup = lpss_uart_setup,
281 	.properties = uart_properties,
282 };
283 
284 static const struct lpss_device_desc byt_spi_dev_desc = {
285 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
286 	.prv_offset = 0x400,
287 };
288 
289 static const struct lpss_device_desc byt_sdio_dev_desc = {
290 	.flags = LPSS_CLK,
291 };
292 
293 static const struct lpss_device_desc byt_i2c_dev_desc = {
294 	.flags = LPSS_CLK | LPSS_SAVE_CTX,
295 	.prv_offset = 0x800,
296 	.setup = byt_i2c_setup,
297 	.resume_from_noirq = true,
298 };
299 
300 static const struct lpss_device_desc bsw_i2c_dev_desc = {
301 	.flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
302 	.prv_offset = 0x800,
303 	.setup = byt_i2c_setup,
304 	.resume_from_noirq = true,
305 };
306 
307 static const struct lpss_device_desc bsw_spi_dev_desc = {
308 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
309 			| LPSS_NO_D3_DELAY,
310 	.prv_offset = 0x400,
311 	.setup = lpss_deassert_reset,
312 };
313 
314 #define ICPU(model)	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }
315 
316 static const struct x86_cpu_id lpss_cpu_ids[] = {
317 	ICPU(INTEL_FAM6_ATOM_SILVERMONT),	/* Valleyview, Bay Trail */
318 	ICPU(INTEL_FAM6_ATOM_AIRMONT),	/* Braswell, Cherry Trail */
319 	{}
320 };
321 
322 #else
323 
324 #define LPSS_ADDR(desc) (0UL)
325 
326 #endif /* CONFIG_X86_INTEL_LPSS */
327 
328 static const struct acpi_device_id acpi_lpss_device_ids[] = {
329 	/* Generic LPSS devices */
330 	{ "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
331 
332 	/* Lynxpoint LPSS devices */
333 	{ "INT33C0", LPSS_ADDR(lpt_dev_desc) },
334 	{ "INT33C1", LPSS_ADDR(lpt_dev_desc) },
335 	{ "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
336 	{ "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
337 	{ "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
338 	{ "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
339 	{ "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
340 	{ "INT33C7", },
341 
342 	/* BayTrail LPSS devices */
343 	{ "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
344 	{ "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
345 	{ "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
346 	{ "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
347 	{ "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
348 	{ "INT33B2", },
349 	{ "INT33FC", },
350 
351 	/* Braswell LPSS devices */
352 	{ "80862286", LPSS_ADDR(lpss_dma_desc) },
353 	{ "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
354 	{ "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
355 	{ "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
356 	{ "808622C0", LPSS_ADDR(lpss_dma_desc) },
357 	{ "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
358 
359 	/* Broadwell LPSS devices */
360 	{ "INT3430", LPSS_ADDR(lpt_dev_desc) },
361 	{ "INT3431", LPSS_ADDR(lpt_dev_desc) },
362 	{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
363 	{ "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
364 	{ "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
365 	{ "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
366 	{ "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
367 	{ "INT3437", },
368 
369 	/* Wildcat Point LPSS devices */
370 	{ "INT3438", LPSS_ADDR(lpt_dev_desc) },
371 
372 	{ }
373 };
374 
375 #ifdef CONFIG_X86_INTEL_LPSS
376 
377 static int is_memory(struct acpi_resource *res, void *not_used)
378 {
379 	struct resource r;
380 	return !acpi_dev_resource_memory(res, &r);
381 }
382 
383 /* LPSS main clock device. */
384 static struct platform_device *lpss_clk_dev;
385 
386 static inline void lpt_register_clock_device(void)
387 {
388 	lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
389 }
390 
391 static int register_device_clock(struct acpi_device *adev,
392 				 struct lpss_private_data *pdata)
393 {
394 	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
395 	const char *devname = dev_name(&adev->dev);
396 	struct clk *clk;
397 	struct lpss_clk_data *clk_data;
398 	const char *parent, *clk_name;
399 	void __iomem *prv_base;
400 
401 	if (!lpss_clk_dev)
402 		lpt_register_clock_device();
403 
404 	clk_data = platform_get_drvdata(lpss_clk_dev);
405 	if (!clk_data)
406 		return -ENODEV;
407 	clk = clk_data->clk;
408 
409 	if (!pdata->mmio_base
410 	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
411 		return -ENODATA;
412 
413 	parent = clk_data->name;
414 	prv_base = pdata->mmio_base + dev_desc->prv_offset;
415 
416 	if (pdata->fixed_clk_rate) {
417 		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
418 					      pdata->fixed_clk_rate);
419 		goto out;
420 	}
421 
422 	if (dev_desc->flags & LPSS_CLK_GATE) {
423 		clk = clk_register_gate(NULL, devname, parent, 0,
424 					prv_base, 0, 0, NULL);
425 		parent = devname;
426 	}
427 
428 	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
429 		/* Prevent division by zero */
430 		if (!readl(prv_base))
431 			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
432 
433 		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
434 		if (!clk_name)
435 			return -ENOMEM;
436 		clk = clk_register_fractional_divider(NULL, clk_name, parent,
437 						      0, prv_base,
438 						      1, 15, 16, 15, 0, NULL);
439 		parent = clk_name;
440 
441 		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
442 		if (!clk_name) {
443 			kfree(parent);
444 			return -ENOMEM;
445 		}
446 		clk = clk_register_gate(NULL, clk_name, parent,
447 					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
448 					prv_base, 31, 0, NULL);
449 		kfree(parent);
450 		kfree(clk_name);
451 	}
452 out:
453 	if (IS_ERR(clk))
454 		return PTR_ERR(clk);
455 
456 	pdata->clk = clk;
457 	clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
458 	return 0;
459 }
460 
461 struct lpss_device_links {
462 	const char *supplier_hid;
463 	const char *supplier_uid;
464 	const char *consumer_hid;
465 	const char *consumer_uid;
466 	u32 flags;
467 };
468 
469 /*
470  * The _DEP method is used to identify dependencies but instead of creating
471  * device links for every handle in _DEP, only links in the following list are
472  * created. That is necessary because, in the general case, _DEP can refer to
473  * devices that might not have drivers, or that are on different buses, or where
474  * the supplier is not enumerated until after the consumer is probed.
475  */
476 static const struct lpss_device_links lpss_device_links[] = {
477 	{"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME},
478 	{"808622C1", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
479 	{"80860F41", "5", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
480 };
481 
482 static bool hid_uid_match(struct acpi_device *adev,
483 			  const char *hid2, const char *uid2)
484 {
485 	const char *hid1 = acpi_device_hid(adev);
486 	const char *uid1 = acpi_device_uid(adev);
487 
488 	if (strcmp(hid1, hid2))
489 		return false;
490 
491 	if (!uid2)
492 		return true;
493 
494 	return uid1 && !strcmp(uid1, uid2);
495 }
496 
497 static bool acpi_lpss_is_supplier(struct acpi_device *adev,
498 				  const struct lpss_device_links *link)
499 {
500 	return hid_uid_match(adev, link->supplier_hid, link->supplier_uid);
501 }
502 
503 static bool acpi_lpss_is_consumer(struct acpi_device *adev,
504 				  const struct lpss_device_links *link)
505 {
506 	return hid_uid_match(adev, link->consumer_hid, link->consumer_uid);
507 }
508 
509 struct hid_uid {
510 	const char *hid;
511 	const char *uid;
512 };
513 
514 static int match_hid_uid(struct device *dev, void *data)
515 {
516 	struct acpi_device *adev = ACPI_COMPANION(dev);
517 	struct hid_uid *id = data;
518 
519 	if (!adev)
520 		return 0;
521 
522 	return hid_uid_match(adev, id->hid, id->uid);
523 }
524 
525 static struct device *acpi_lpss_find_device(const char *hid, const char *uid)
526 {
527 	struct device *dev;
528 
529 	struct hid_uid data = {
530 		.hid = hid,
531 		.uid = uid,
532 	};
533 
534 	dev = bus_find_device(&platform_bus_type, NULL, &data, match_hid_uid);
535 	if (dev)
536 		return dev;
537 
538 	return bus_find_device(&pci_bus_type, NULL, &data, match_hid_uid);
539 }
540 
541 static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle)
542 {
543 	struct acpi_handle_list dep_devices;
544 	acpi_status status;
545 	int i;
546 
547 	if (!acpi_has_method(adev->handle, "_DEP"))
548 		return false;
549 
550 	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
551 					 &dep_devices);
552 	if (ACPI_FAILURE(status)) {
553 		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
554 		return false;
555 	}
556 
557 	for (i = 0; i < dep_devices.count; i++) {
558 		if (dep_devices.handles[i] == handle)
559 			return true;
560 	}
561 
562 	return false;
563 }
564 
565 static void acpi_lpss_link_consumer(struct device *dev1,
566 				    const struct lpss_device_links *link)
567 {
568 	struct device *dev2;
569 
570 	dev2 = acpi_lpss_find_device(link->consumer_hid, link->consumer_uid);
571 	if (!dev2)
572 		return;
573 
574 	if (acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1)))
575 		device_link_add(dev2, dev1, link->flags);
576 
577 	put_device(dev2);
578 }
579 
580 static void acpi_lpss_link_supplier(struct device *dev1,
581 				    const struct lpss_device_links *link)
582 {
583 	struct device *dev2;
584 
585 	dev2 = acpi_lpss_find_device(link->supplier_hid, link->supplier_uid);
586 	if (!dev2)
587 		return;
588 
589 	if (acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2)))
590 		device_link_add(dev1, dev2, link->flags);
591 
592 	put_device(dev2);
593 }
594 
595 static void acpi_lpss_create_device_links(struct acpi_device *adev,
596 					  struct platform_device *pdev)
597 {
598 	int i;
599 
600 	for (i = 0; i < ARRAY_SIZE(lpss_device_links); i++) {
601 		const struct lpss_device_links *link = &lpss_device_links[i];
602 
603 		if (acpi_lpss_is_supplier(adev, link))
604 			acpi_lpss_link_consumer(&pdev->dev, link);
605 
606 		if (acpi_lpss_is_consumer(adev, link))
607 			acpi_lpss_link_supplier(&pdev->dev, link);
608 	}
609 }
610 
611 static int acpi_lpss_create_device(struct acpi_device *adev,
612 				   const struct acpi_device_id *id)
613 {
614 	const struct lpss_device_desc *dev_desc;
615 	struct lpss_private_data *pdata;
616 	struct resource_entry *rentry;
617 	struct list_head resource_list;
618 	struct platform_device *pdev;
619 	int ret;
620 
621 	dev_desc = (const struct lpss_device_desc *)id->driver_data;
622 	if (!dev_desc) {
623 		pdev = acpi_create_platform_device(adev, NULL);
624 		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
625 	}
626 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
627 	if (!pdata)
628 		return -ENOMEM;
629 
630 	INIT_LIST_HEAD(&resource_list);
631 	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
632 	if (ret < 0)
633 		goto err_out;
634 
635 	list_for_each_entry(rentry, &resource_list, node)
636 		if (resource_type(rentry->res) == IORESOURCE_MEM) {
637 			if (dev_desc->prv_size_override)
638 				pdata->mmio_size = dev_desc->prv_size_override;
639 			else
640 				pdata->mmio_size = resource_size(rentry->res);
641 			pdata->mmio_base = ioremap(rentry->res->start,
642 						   pdata->mmio_size);
643 			break;
644 		}
645 
646 	acpi_dev_free_resource_list(&resource_list);
647 
648 	if (!pdata->mmio_base) {
649 		/* Avoid acpi_bus_attach() instantiating a pdev for this dev. */
650 		adev->pnp.type.platform_id = 0;
651 		/* Skip the device, but continue the namespace scan. */
652 		ret = 0;
653 		goto err_out;
654 	}
655 
656 	pdata->adev = adev;
657 	pdata->dev_desc = dev_desc;
658 
659 	if (dev_desc->setup)
660 		dev_desc->setup(pdata);
661 
662 	if (dev_desc->flags & LPSS_CLK) {
663 		ret = register_device_clock(adev, pdata);
664 		if (ret) {
665 			/* Skip the device, but continue the namespace scan. */
666 			ret = 0;
667 			goto err_out;
668 		}
669 	}
670 
671 	/*
672 	 * This works around a known issue in ACPI tables where LPSS devices
673 	 * have _PS0 and _PS3 without _PSC (and no power resources), so
674 	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
675 	 */
676 	acpi_device_fix_up_power(adev);
677 
678 	adev->driver_data = pdata;
679 	pdev = acpi_create_platform_device(adev, dev_desc->properties);
680 	if (!IS_ERR_OR_NULL(pdev)) {
681 		acpi_lpss_create_device_links(adev, pdev);
682 		return 1;
683 	}
684 
685 	ret = PTR_ERR(pdev);
686 	adev->driver_data = NULL;
687 
688  err_out:
689 	kfree(pdata);
690 	return ret;
691 }
692 
693 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
694 {
695 	return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
696 }
697 
698 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
699 			     unsigned int reg)
700 {
701 	writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
702 }
703 
704 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
705 {
706 	struct acpi_device *adev;
707 	struct lpss_private_data *pdata;
708 	unsigned long flags;
709 	int ret;
710 
711 	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
712 	if (WARN_ON(ret))
713 		return ret;
714 
715 	spin_lock_irqsave(&dev->power.lock, flags);
716 	if (pm_runtime_suspended(dev)) {
717 		ret = -EAGAIN;
718 		goto out;
719 	}
720 	pdata = acpi_driver_data(adev);
721 	if (WARN_ON(!pdata || !pdata->mmio_base)) {
722 		ret = -ENODEV;
723 		goto out;
724 	}
725 	*val = __lpss_reg_read(pdata, reg);
726 
727  out:
728 	spin_unlock_irqrestore(&dev->power.lock, flags);
729 	return ret;
730 }
731 
732 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
733 			     char *buf)
734 {
735 	u32 ltr_value = 0;
736 	unsigned int reg;
737 	int ret;
738 
739 	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
740 	ret = lpss_reg_read(dev, reg, &ltr_value);
741 	if (ret)
742 		return ret;
743 
744 	return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
745 }
746 
747 static ssize_t lpss_ltr_mode_show(struct device *dev,
748 				  struct device_attribute *attr, char *buf)
749 {
750 	u32 ltr_mode = 0;
751 	char *outstr;
752 	int ret;
753 
754 	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
755 	if (ret)
756 		return ret;
757 
758 	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
759 	return sprintf(buf, "%s\n", outstr);
760 }
761 
762 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
763 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
764 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
765 
766 static struct attribute *lpss_attrs[] = {
767 	&dev_attr_auto_ltr.attr,
768 	&dev_attr_sw_ltr.attr,
769 	&dev_attr_ltr_mode.attr,
770 	NULL,
771 };
772 
773 static const struct attribute_group lpss_attr_group = {
774 	.attrs = lpss_attrs,
775 	.name = "lpss_ltr",
776 };
777 
778 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
779 {
780 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
781 	u32 ltr_mode, ltr_val;
782 
783 	ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
784 	if (val < 0) {
785 		if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
786 			ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
787 			__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
788 		}
789 		return;
790 	}
791 	ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
792 	if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
793 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
794 		val = LPSS_LTR_MAX_VAL;
795 	} else if (val > LPSS_LTR_MAX_VAL) {
796 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
797 		val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
798 	} else {
799 		ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
800 	}
801 	ltr_val |= val;
802 	__lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
803 	if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
804 		ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
805 		__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
806 	}
807 }
808 
809 #ifdef CONFIG_PM
810 /**
811  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
812  * @dev: LPSS device
813  * @pdata: pointer to the private data of the LPSS device
814  *
815  * Most LPSS devices have private registers which may loose their context when
816  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
817  * prv_reg_ctx array.
818  */
819 static void acpi_lpss_save_ctx(struct device *dev,
820 			       struct lpss_private_data *pdata)
821 {
822 	unsigned int i;
823 
824 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
825 		unsigned long offset = i * sizeof(u32);
826 
827 		pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
828 		dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
829 			pdata->prv_reg_ctx[i], offset);
830 	}
831 }
832 
833 /**
834  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
835  * @dev: LPSS device
836  * @pdata: pointer to the private data of the LPSS device
837  *
838  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
839  */
840 static void acpi_lpss_restore_ctx(struct device *dev,
841 				  struct lpss_private_data *pdata)
842 {
843 	unsigned int i;
844 
845 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
846 		unsigned long offset = i * sizeof(u32);
847 
848 		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
849 		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
850 			pdata->prv_reg_ctx[i], offset);
851 	}
852 }
853 
854 static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
855 {
856 	/*
857 	 * The following delay is needed or the subsequent write operations may
858 	 * fail. The LPSS devices are actually PCI devices and the PCI spec
859 	 * expects 10ms delay before the device can be accessed after D3 to D0
860 	 * transition. However some platforms like BSW does not need this delay.
861 	 */
862 	unsigned int delay = 10;	/* default 10ms delay */
863 
864 	if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
865 		delay = 0;
866 
867 	msleep(delay);
868 }
869 
870 static int acpi_lpss_activate(struct device *dev)
871 {
872 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
873 	int ret;
874 
875 	ret = acpi_dev_resume(dev);
876 	if (ret)
877 		return ret;
878 
879 	acpi_lpss_d3_to_d0_delay(pdata);
880 
881 	/*
882 	 * This is called only on ->probe() stage where a device is either in
883 	 * known state defined by BIOS or most likely powered off. Due to this
884 	 * we have to deassert reset line to be sure that ->probe() will
885 	 * recognize the device.
886 	 */
887 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
888 		lpss_deassert_reset(pdata);
889 
890 	return 0;
891 }
892 
893 static void acpi_lpss_dismiss(struct device *dev)
894 {
895 	acpi_dev_suspend(dev, false);
896 }
897 
898 /* IOSF SB for LPSS island */
899 #define LPSS_IOSF_UNIT_LPIOEP		0xA0
900 #define LPSS_IOSF_UNIT_LPIO1		0xAB
901 #define LPSS_IOSF_UNIT_LPIO2		0xAC
902 
903 #define LPSS_IOSF_PMCSR			0x84
904 #define LPSS_PMCSR_D0			0
905 #define LPSS_PMCSR_D3hot		3
906 #define LPSS_PMCSR_Dx_MASK		GENMASK(1, 0)
907 
908 #define LPSS_IOSF_GPIODEF0		0x154
909 #define LPSS_GPIODEF0_DMA1_D3		BIT(2)
910 #define LPSS_GPIODEF0_DMA2_D3		BIT(3)
911 #define LPSS_GPIODEF0_DMA_D3_MASK	GENMASK(3, 2)
912 #define LPSS_GPIODEF0_DMA_LLP		BIT(13)
913 
914 static DEFINE_MUTEX(lpss_iosf_mutex);
915 static bool lpss_iosf_d3_entered = true;
916 
917 static void lpss_iosf_enter_d3_state(void)
918 {
919 	u32 value1 = 0;
920 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
921 	u32 value2 = LPSS_PMCSR_D3hot;
922 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
923 	/*
924 	 * PMC provides an information about actual status of the LPSS devices.
925 	 * Here we read the values related to LPSS power island, i.e. LPSS
926 	 * devices, excluding both LPSS DMA controllers, along with SCC domain.
927 	 */
928 	u32 func_dis, d3_sts_0, pmc_status;
929 	int ret;
930 
931 	ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
932 	if (ret)
933 		return;
934 
935 	mutex_lock(&lpss_iosf_mutex);
936 
937 	ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
938 	if (ret)
939 		goto exit;
940 
941 	/*
942 	 * Get the status of entire LPSS power island per device basis.
943 	 * Shutdown both LPSS DMA controllers if and only if all other devices
944 	 * are already in D3hot.
945 	 */
946 	pmc_status = (~(d3_sts_0 | func_dis)) & pmc_atom_d3_mask;
947 	if (pmc_status)
948 		goto exit;
949 
950 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
951 			LPSS_IOSF_PMCSR, value2, mask2);
952 
953 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
954 			LPSS_IOSF_PMCSR, value2, mask2);
955 
956 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
957 			LPSS_IOSF_GPIODEF0, value1, mask1);
958 
959 	lpss_iosf_d3_entered = true;
960 
961 exit:
962 	mutex_unlock(&lpss_iosf_mutex);
963 }
964 
965 static void lpss_iosf_exit_d3_state(void)
966 {
967 	u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3 |
968 		     LPSS_GPIODEF0_DMA_LLP;
969 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
970 	u32 value2 = LPSS_PMCSR_D0;
971 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
972 
973 	mutex_lock(&lpss_iosf_mutex);
974 
975 	if (!lpss_iosf_d3_entered)
976 		goto exit;
977 
978 	lpss_iosf_d3_entered = false;
979 
980 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
981 			LPSS_IOSF_GPIODEF0, value1, mask1);
982 
983 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
984 			LPSS_IOSF_PMCSR, value2, mask2);
985 
986 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
987 			LPSS_IOSF_PMCSR, value2, mask2);
988 
989 exit:
990 	mutex_unlock(&lpss_iosf_mutex);
991 }
992 
993 static int acpi_lpss_suspend(struct device *dev, bool wakeup)
994 {
995 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
996 	int ret;
997 
998 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
999 		acpi_lpss_save_ctx(dev, pdata);
1000 
1001 	ret = acpi_dev_suspend(dev, wakeup);
1002 
1003 	/*
1004 	 * This call must be last in the sequence, otherwise PMC will return
1005 	 * wrong status for devices being about to be powered off. See
1006 	 * lpss_iosf_enter_d3_state() for further information.
1007 	 */
1008 	if (acpi_target_system_state() == ACPI_STATE_S0 &&
1009 	    lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1010 		lpss_iosf_enter_d3_state();
1011 
1012 	return ret;
1013 }
1014 
1015 static int acpi_lpss_resume(struct device *dev)
1016 {
1017 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1018 	int ret;
1019 
1020 	/*
1021 	 * This call is kept first to be in symmetry with
1022 	 * acpi_lpss_runtime_suspend() one.
1023 	 */
1024 	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1025 		lpss_iosf_exit_d3_state();
1026 
1027 	ret = acpi_dev_resume(dev);
1028 	if (ret)
1029 		return ret;
1030 
1031 	acpi_lpss_d3_to_d0_delay(pdata);
1032 
1033 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
1034 		acpi_lpss_restore_ctx(dev, pdata);
1035 
1036 	return 0;
1037 }
1038 
1039 #ifdef CONFIG_PM_SLEEP
1040 static int acpi_lpss_do_suspend_late(struct device *dev)
1041 {
1042 	int ret;
1043 
1044 	if (dev_pm_smart_suspend_and_suspended(dev))
1045 		return 0;
1046 
1047 	ret = pm_generic_suspend_late(dev);
1048 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1049 }
1050 
1051 static int acpi_lpss_suspend_late(struct device *dev)
1052 {
1053 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1054 
1055 	if (pdata->dev_desc->resume_from_noirq)
1056 		return 0;
1057 
1058 	return acpi_lpss_do_suspend_late(dev);
1059 }
1060 
1061 static int acpi_lpss_suspend_noirq(struct device *dev)
1062 {
1063 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1064 	int ret;
1065 
1066 	if (pdata->dev_desc->resume_from_noirq) {
1067 		ret = acpi_lpss_do_suspend_late(dev);
1068 		if (ret)
1069 			return ret;
1070 	}
1071 
1072 	return acpi_subsys_suspend_noirq(dev);
1073 }
1074 
1075 static int acpi_lpss_do_resume_early(struct device *dev)
1076 {
1077 	int ret = acpi_lpss_resume(dev);
1078 
1079 	return ret ? ret : pm_generic_resume_early(dev);
1080 }
1081 
1082 static int acpi_lpss_resume_early(struct device *dev)
1083 {
1084 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1085 
1086 	if (pdata->dev_desc->resume_from_noirq)
1087 		return 0;
1088 
1089 	return acpi_lpss_do_resume_early(dev);
1090 }
1091 
1092 static int acpi_lpss_resume_noirq(struct device *dev)
1093 {
1094 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1095 	int ret;
1096 
1097 	ret = acpi_subsys_resume_noirq(dev);
1098 	if (ret)
1099 		return ret;
1100 
1101 	if (!dev_pm_may_skip_resume(dev) && pdata->dev_desc->resume_from_noirq)
1102 		ret = acpi_lpss_do_resume_early(dev);
1103 
1104 	return ret;
1105 }
1106 
1107 #endif /* CONFIG_PM_SLEEP */
1108 
1109 static int acpi_lpss_runtime_suspend(struct device *dev)
1110 {
1111 	int ret = pm_generic_runtime_suspend(dev);
1112 
1113 	return ret ? ret : acpi_lpss_suspend(dev, true);
1114 }
1115 
1116 static int acpi_lpss_runtime_resume(struct device *dev)
1117 {
1118 	int ret = acpi_lpss_resume(dev);
1119 
1120 	return ret ? ret : pm_generic_runtime_resume(dev);
1121 }
1122 #endif /* CONFIG_PM */
1123 
1124 static struct dev_pm_domain acpi_lpss_pm_domain = {
1125 #ifdef CONFIG_PM
1126 	.activate = acpi_lpss_activate,
1127 	.dismiss = acpi_lpss_dismiss,
1128 #endif
1129 	.ops = {
1130 #ifdef CONFIG_PM
1131 #ifdef CONFIG_PM_SLEEP
1132 		.prepare = acpi_subsys_prepare,
1133 		.complete = acpi_subsys_complete,
1134 		.suspend = acpi_subsys_suspend,
1135 		.suspend_late = acpi_lpss_suspend_late,
1136 		.suspend_noirq = acpi_lpss_suspend_noirq,
1137 		.resume_noirq = acpi_lpss_resume_noirq,
1138 		.resume_early = acpi_lpss_resume_early,
1139 		.freeze = acpi_subsys_freeze,
1140 		.freeze_late = acpi_subsys_freeze_late,
1141 		.freeze_noirq = acpi_subsys_freeze_noirq,
1142 		.thaw_noirq = acpi_subsys_thaw_noirq,
1143 		.poweroff = acpi_subsys_suspend,
1144 		.poweroff_late = acpi_lpss_suspend_late,
1145 		.poweroff_noirq = acpi_subsys_suspend_noirq,
1146 		.restore_noirq = acpi_subsys_resume_noirq,
1147 		.restore_early = acpi_lpss_resume_early,
1148 #endif
1149 		.runtime_suspend = acpi_lpss_runtime_suspend,
1150 		.runtime_resume = acpi_lpss_runtime_resume,
1151 #endif
1152 	},
1153 };
1154 
1155 static int acpi_lpss_platform_notify(struct notifier_block *nb,
1156 				     unsigned long action, void *data)
1157 {
1158 	struct platform_device *pdev = to_platform_device(data);
1159 	struct lpss_private_data *pdata;
1160 	struct acpi_device *adev;
1161 	const struct acpi_device_id *id;
1162 
1163 	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
1164 	if (!id || !id->driver_data)
1165 		return 0;
1166 
1167 	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
1168 		return 0;
1169 
1170 	pdata = acpi_driver_data(adev);
1171 	if (!pdata)
1172 		return 0;
1173 
1174 	if (pdata->mmio_base &&
1175 	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
1176 		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
1177 		return 0;
1178 	}
1179 
1180 	switch (action) {
1181 	case BUS_NOTIFY_BIND_DRIVER:
1182 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1183 		break;
1184 	case BUS_NOTIFY_DRIVER_NOT_BOUND:
1185 	case BUS_NOTIFY_UNBOUND_DRIVER:
1186 		dev_pm_domain_set(&pdev->dev, NULL);
1187 		break;
1188 	case BUS_NOTIFY_ADD_DEVICE:
1189 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1190 		if (pdata->dev_desc->flags & LPSS_LTR)
1191 			return sysfs_create_group(&pdev->dev.kobj,
1192 						  &lpss_attr_group);
1193 		break;
1194 	case BUS_NOTIFY_DEL_DEVICE:
1195 		if (pdata->dev_desc->flags & LPSS_LTR)
1196 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
1197 		dev_pm_domain_set(&pdev->dev, NULL);
1198 		break;
1199 	default:
1200 		break;
1201 	}
1202 
1203 	return 0;
1204 }
1205 
1206 static struct notifier_block acpi_lpss_nb = {
1207 	.notifier_call = acpi_lpss_platform_notify,
1208 };
1209 
1210 static void acpi_lpss_bind(struct device *dev)
1211 {
1212 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1213 
1214 	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
1215 		return;
1216 
1217 	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
1218 		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
1219 	else
1220 		dev_err(dev, "MMIO size insufficient to access LTR\n");
1221 }
1222 
1223 static void acpi_lpss_unbind(struct device *dev)
1224 {
1225 	dev->power.set_latency_tolerance = NULL;
1226 }
1227 
1228 static struct acpi_scan_handler lpss_handler = {
1229 	.ids = acpi_lpss_device_ids,
1230 	.attach = acpi_lpss_create_device,
1231 	.bind = acpi_lpss_bind,
1232 	.unbind = acpi_lpss_unbind,
1233 };
1234 
1235 void __init acpi_lpss_init(void)
1236 {
1237 	const struct x86_cpu_id *id;
1238 	int ret;
1239 
1240 	ret = lpt_clk_init();
1241 	if (ret)
1242 		return;
1243 
1244 	id = x86_match_cpu(lpss_cpu_ids);
1245 	if (id)
1246 		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
1247 
1248 	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
1249 	acpi_scan_add_handler(&lpss_handler);
1250 }
1251 
1252 #else
1253 
1254 static struct acpi_scan_handler lpss_handler = {
1255 	.ids = acpi_lpss_device_ids,
1256 };
1257 
1258 void __init acpi_lpss_init(void)
1259 {
1260 	acpi_scan_add_handler(&lpss_handler);
1261 }
1262 
1263 #endif /* CONFIG_X86_INTEL_LPSS */
1264