xref: /openbmc/linux/drivers/acpi/acpi_lpss.c (revision b8265621)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ACPI support for Intel Lynxpoint LPSS.
4  *
5  * Copyright (C) 2013, Intel Corporation
6  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
7  *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
8  */
9 
10 #include <linux/acpi.h>
11 #include <linux/clkdev.h>
12 #include <linux/clk-provider.h>
13 #include <linux/dmi.h>
14 #include <linux/err.h>
15 #include <linux/io.h>
16 #include <linux/mutex.h>
17 #include <linux/pci.h>
18 #include <linux/platform_device.h>
19 #include <linux/platform_data/x86/clk-lpss.h>
20 #include <linux/platform_data/x86/pmc_atom.h>
21 #include <linux/pm_domain.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/pwm.h>
24 #include <linux/suspend.h>
25 #include <linux/delay.h>
26 
27 #include "internal.h"
28 
29 ACPI_MODULE_NAME("acpi_lpss");
30 
31 #ifdef CONFIG_X86_INTEL_LPSS
32 
33 #include <asm/cpu_device_id.h>
34 #include <asm/intel-family.h>
35 #include <asm/iosf_mbi.h>
36 
37 #define LPSS_ADDR(desc) ((unsigned long)&desc)
38 
39 #define LPSS_CLK_SIZE	0x04
40 #define LPSS_LTR_SIZE	0x18
41 
42 /* Offsets relative to LPSS_PRIVATE_OFFSET */
43 #define LPSS_CLK_DIVIDER_DEF_MASK	(BIT(1) | BIT(16))
44 #define LPSS_RESETS			0x04
45 #define LPSS_RESETS_RESET_FUNC		BIT(0)
46 #define LPSS_RESETS_RESET_APB		BIT(1)
47 #define LPSS_GENERAL			0x08
48 #define LPSS_GENERAL_LTR_MODE_SW	BIT(2)
49 #define LPSS_GENERAL_UART_RTS_OVRD	BIT(3)
50 #define LPSS_SW_LTR			0x10
51 #define LPSS_AUTO_LTR			0x14
52 #define LPSS_LTR_SNOOP_REQ		BIT(15)
53 #define LPSS_LTR_SNOOP_MASK		0x0000FFFF
54 #define LPSS_LTR_SNOOP_LAT_1US		0x800
55 #define LPSS_LTR_SNOOP_LAT_32US		0xC00
56 #define LPSS_LTR_SNOOP_LAT_SHIFT	5
57 #define LPSS_LTR_SNOOP_LAT_CUTOFF	3000
58 #define LPSS_LTR_MAX_VAL		0x3FF
59 #define LPSS_TX_INT			0x20
60 #define LPSS_TX_INT_MASK		BIT(1)
61 
62 #define LPSS_PRV_REG_COUNT		9
63 
64 /* LPSS Flags */
65 #define LPSS_CLK			BIT(0)
66 #define LPSS_CLK_GATE			BIT(1)
67 #define LPSS_CLK_DIVIDER		BIT(2)
68 #define LPSS_LTR			BIT(3)
69 #define LPSS_SAVE_CTX			BIT(4)
70 #define LPSS_NO_D3_DELAY		BIT(5)
71 
72 struct lpss_private_data;
73 
74 struct lpss_device_desc {
75 	unsigned int flags;
76 	const char *clk_con_id;
77 	unsigned int prv_offset;
78 	size_t prv_size_override;
79 	struct property_entry *properties;
80 	void (*setup)(struct lpss_private_data *pdata);
81 	bool resume_from_noirq;
82 };
83 
84 static const struct lpss_device_desc lpss_dma_desc = {
85 	.flags = LPSS_CLK,
86 };
87 
88 struct lpss_private_data {
89 	struct acpi_device *adev;
90 	void __iomem *mmio_base;
91 	resource_size_t mmio_size;
92 	unsigned int fixed_clk_rate;
93 	struct clk *clk;
94 	const struct lpss_device_desc *dev_desc;
95 	u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
96 };
97 
98 /* Devices which need to be in D3 before lpss_iosf_enter_d3_state() proceeds */
99 static u32 pmc_atom_d3_mask = 0xfe000ffe;
100 
101 /* LPSS run time quirks */
102 static unsigned int lpss_quirks;
103 
104 /*
105  * LPSS_QUIRK_ALWAYS_POWER_ON: override power state for LPSS DMA device.
106  *
107  * The LPSS DMA controller has neither _PS0 nor _PS3 method. Moreover
108  * it can be powered off automatically whenever the last LPSS device goes down.
109  * In case of no power any access to the DMA controller will hang the system.
110  * The behaviour is reproduced on some HP laptops based on Intel BayTrail as
111  * well as on ASuS T100TA transformer.
112  *
113  * This quirk overrides power state of entire LPSS island to keep DMA powered
114  * on whenever we have at least one other device in use.
115  */
116 #define LPSS_QUIRK_ALWAYS_POWER_ON	BIT(0)
117 
118 /* UART Component Parameter Register */
119 #define LPSS_UART_CPR			0xF4
120 #define LPSS_UART_CPR_AFCE		BIT(4)
121 
122 static void lpss_uart_setup(struct lpss_private_data *pdata)
123 {
124 	unsigned int offset;
125 	u32 val;
126 
127 	offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
128 	val = readl(pdata->mmio_base + offset);
129 	writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
130 
131 	val = readl(pdata->mmio_base + LPSS_UART_CPR);
132 	if (!(val & LPSS_UART_CPR_AFCE)) {
133 		offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
134 		val = readl(pdata->mmio_base + offset);
135 		val |= LPSS_GENERAL_UART_RTS_OVRD;
136 		writel(val, pdata->mmio_base + offset);
137 	}
138 }
139 
140 static void lpss_deassert_reset(struct lpss_private_data *pdata)
141 {
142 	unsigned int offset;
143 	u32 val;
144 
145 	offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
146 	val = readl(pdata->mmio_base + offset);
147 	val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
148 	writel(val, pdata->mmio_base + offset);
149 }
150 
151 /*
152  * BYT PWM used for backlight control by the i915 driver on systems without
153  * the Crystal Cove PMIC.
154  */
155 static struct pwm_lookup byt_pwm_lookup[] = {
156 	PWM_LOOKUP_WITH_MODULE("80860F09:00", 0, "0000:00:02.0",
157 			       "pwm_soc_backlight", 0, PWM_POLARITY_NORMAL,
158 			       "pwm-lpss-platform"),
159 };
160 
161 static void byt_pwm_setup(struct lpss_private_data *pdata)
162 {
163 	struct acpi_device *adev = pdata->adev;
164 
165 	/* Only call pwm_add_table for the first PWM controller */
166 	if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
167 		return;
168 
169 	pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup));
170 }
171 
172 #define LPSS_I2C_ENABLE			0x6c
173 
174 static void byt_i2c_setup(struct lpss_private_data *pdata)
175 {
176 	const char *uid_str = acpi_device_uid(pdata->adev);
177 	acpi_handle handle = pdata->adev->handle;
178 	unsigned long long shared_host = 0;
179 	acpi_status status;
180 	long uid = 0;
181 
182 	/* Expected to always be true, but better safe then sorry */
183 	if (uid_str)
184 		uid = simple_strtol(uid_str, NULL, 10);
185 
186 	/* Detect I2C bus shared with PUNIT and ignore its d3 status */
187 	status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
188 	if (ACPI_SUCCESS(status) && shared_host && uid)
189 		pmc_atom_d3_mask &= ~(BIT_LPSS2_F1_I2C1 << (uid - 1));
190 
191 	lpss_deassert_reset(pdata);
192 
193 	if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
194 		pdata->fixed_clk_rate = 133000000;
195 
196 	writel(0, pdata->mmio_base + LPSS_I2C_ENABLE);
197 }
198 
199 /* BSW PWM used for backlight control by the i915 driver */
200 static struct pwm_lookup bsw_pwm_lookup[] = {
201 	PWM_LOOKUP_WITH_MODULE("80862288:00", 0, "0000:00:02.0",
202 			       "pwm_soc_backlight", 0, PWM_POLARITY_NORMAL,
203 			       "pwm-lpss-platform"),
204 };
205 
206 static void bsw_pwm_setup(struct lpss_private_data *pdata)
207 {
208 	struct acpi_device *adev = pdata->adev;
209 
210 	/* Only call pwm_add_table for the first PWM controller */
211 	if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
212 		return;
213 
214 	pwm_add_table(bsw_pwm_lookup, ARRAY_SIZE(bsw_pwm_lookup));
215 }
216 
217 static const struct lpss_device_desc lpt_dev_desc = {
218 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR
219 			| LPSS_SAVE_CTX,
220 	.prv_offset = 0x800,
221 };
222 
223 static const struct lpss_device_desc lpt_i2c_dev_desc = {
224 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR | LPSS_SAVE_CTX,
225 	.prv_offset = 0x800,
226 };
227 
228 static struct property_entry uart_properties[] = {
229 	PROPERTY_ENTRY_U32("reg-io-width", 4),
230 	PROPERTY_ENTRY_U32("reg-shift", 2),
231 	PROPERTY_ENTRY_BOOL("snps,uart-16550-compatible"),
232 	{ },
233 };
234 
235 static const struct lpss_device_desc lpt_uart_dev_desc = {
236 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR
237 			| LPSS_SAVE_CTX,
238 	.clk_con_id = "baudclk",
239 	.prv_offset = 0x800,
240 	.setup = lpss_uart_setup,
241 	.properties = uart_properties,
242 };
243 
244 static const struct lpss_device_desc lpt_sdio_dev_desc = {
245 	.flags = LPSS_LTR,
246 	.prv_offset = 0x1000,
247 	.prv_size_override = 0x1018,
248 };
249 
250 static const struct lpss_device_desc byt_pwm_dev_desc = {
251 	.flags = LPSS_SAVE_CTX,
252 	.prv_offset = 0x800,
253 	.setup = byt_pwm_setup,
254 };
255 
256 static const struct lpss_device_desc bsw_pwm_dev_desc = {
257 	.flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
258 	.prv_offset = 0x800,
259 	.setup = bsw_pwm_setup,
260 };
261 
262 static const struct lpss_device_desc byt_uart_dev_desc = {
263 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
264 	.clk_con_id = "baudclk",
265 	.prv_offset = 0x800,
266 	.setup = lpss_uart_setup,
267 	.properties = uart_properties,
268 };
269 
270 static const struct lpss_device_desc bsw_uart_dev_desc = {
271 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
272 			| LPSS_NO_D3_DELAY,
273 	.clk_con_id = "baudclk",
274 	.prv_offset = 0x800,
275 	.setup = lpss_uart_setup,
276 	.properties = uart_properties,
277 };
278 
279 static const struct lpss_device_desc byt_spi_dev_desc = {
280 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
281 	.prv_offset = 0x400,
282 };
283 
284 static const struct lpss_device_desc byt_sdio_dev_desc = {
285 	.flags = LPSS_CLK,
286 };
287 
288 static const struct lpss_device_desc byt_i2c_dev_desc = {
289 	.flags = LPSS_CLK | LPSS_SAVE_CTX,
290 	.prv_offset = 0x800,
291 	.setup = byt_i2c_setup,
292 	.resume_from_noirq = true,
293 };
294 
295 static const struct lpss_device_desc bsw_i2c_dev_desc = {
296 	.flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
297 	.prv_offset = 0x800,
298 	.setup = byt_i2c_setup,
299 	.resume_from_noirq = true,
300 };
301 
302 static const struct lpss_device_desc bsw_spi_dev_desc = {
303 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
304 			| LPSS_NO_D3_DELAY,
305 	.prv_offset = 0x400,
306 	.setup = lpss_deassert_reset,
307 };
308 
309 static const struct x86_cpu_id lpss_cpu_ids[] = {
310 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT,	NULL),
311 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT,	NULL),
312 	{}
313 };
314 
315 #else
316 
317 #define LPSS_ADDR(desc) (0UL)
318 
319 #endif /* CONFIG_X86_INTEL_LPSS */
320 
321 static const struct acpi_device_id acpi_lpss_device_ids[] = {
322 	/* Generic LPSS devices */
323 	{ "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
324 
325 	/* Lynxpoint LPSS devices */
326 	{ "INT33C0", LPSS_ADDR(lpt_dev_desc) },
327 	{ "INT33C1", LPSS_ADDR(lpt_dev_desc) },
328 	{ "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
329 	{ "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
330 	{ "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
331 	{ "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
332 	{ "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
333 	{ "INT33C7", },
334 
335 	/* BayTrail LPSS devices */
336 	{ "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
337 	{ "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
338 	{ "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
339 	{ "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
340 	{ "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
341 	{ "INT33B2", },
342 	{ "INT33FC", },
343 
344 	/* Braswell LPSS devices */
345 	{ "80862286", LPSS_ADDR(lpss_dma_desc) },
346 	{ "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
347 	{ "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
348 	{ "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
349 	{ "808622C0", LPSS_ADDR(lpss_dma_desc) },
350 	{ "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
351 
352 	/* Broadwell LPSS devices */
353 	{ "INT3430", LPSS_ADDR(lpt_dev_desc) },
354 	{ "INT3431", LPSS_ADDR(lpt_dev_desc) },
355 	{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
356 	{ "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
357 	{ "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
358 	{ "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
359 	{ "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
360 	{ "INT3437", },
361 
362 	/* Wildcat Point LPSS devices */
363 	{ "INT3438", LPSS_ADDR(lpt_dev_desc) },
364 
365 	{ }
366 };
367 
368 #ifdef CONFIG_X86_INTEL_LPSS
369 
370 static int is_memory(struct acpi_resource *res, void *not_used)
371 {
372 	struct resource r;
373 	return !acpi_dev_resource_memory(res, &r);
374 }
375 
376 /* LPSS main clock device. */
377 static struct platform_device *lpss_clk_dev;
378 
379 static inline void lpt_register_clock_device(void)
380 {
381 	lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
382 }
383 
384 static int register_device_clock(struct acpi_device *adev,
385 				 struct lpss_private_data *pdata)
386 {
387 	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
388 	const char *devname = dev_name(&adev->dev);
389 	struct clk *clk;
390 	struct lpss_clk_data *clk_data;
391 	const char *parent, *clk_name;
392 	void __iomem *prv_base;
393 
394 	if (!lpss_clk_dev)
395 		lpt_register_clock_device();
396 
397 	clk_data = platform_get_drvdata(lpss_clk_dev);
398 	if (!clk_data)
399 		return -ENODEV;
400 	clk = clk_data->clk;
401 
402 	if (!pdata->mmio_base
403 	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
404 		return -ENODATA;
405 
406 	parent = clk_data->name;
407 	prv_base = pdata->mmio_base + dev_desc->prv_offset;
408 
409 	if (pdata->fixed_clk_rate) {
410 		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
411 					      pdata->fixed_clk_rate);
412 		goto out;
413 	}
414 
415 	if (dev_desc->flags & LPSS_CLK_GATE) {
416 		clk = clk_register_gate(NULL, devname, parent, 0,
417 					prv_base, 0, 0, NULL);
418 		parent = devname;
419 	}
420 
421 	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
422 		/* Prevent division by zero */
423 		if (!readl(prv_base))
424 			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
425 
426 		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
427 		if (!clk_name)
428 			return -ENOMEM;
429 		clk = clk_register_fractional_divider(NULL, clk_name, parent,
430 						      0, prv_base,
431 						      1, 15, 16, 15, 0, NULL);
432 		parent = clk_name;
433 
434 		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
435 		if (!clk_name) {
436 			kfree(parent);
437 			return -ENOMEM;
438 		}
439 		clk = clk_register_gate(NULL, clk_name, parent,
440 					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
441 					prv_base, 31, 0, NULL);
442 		kfree(parent);
443 		kfree(clk_name);
444 	}
445 out:
446 	if (IS_ERR(clk))
447 		return PTR_ERR(clk);
448 
449 	pdata->clk = clk;
450 	clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
451 	return 0;
452 }
453 
454 struct lpss_device_links {
455 	const char *supplier_hid;
456 	const char *supplier_uid;
457 	const char *consumer_hid;
458 	const char *consumer_uid;
459 	u32 flags;
460 	const struct dmi_system_id *dep_missing_ids;
461 };
462 
463 /* Please keep this list sorted alphabetically by vendor and model */
464 static const struct dmi_system_id i2c1_dep_missing_dmi_ids[] = {
465 	{
466 		.matches = {
467 			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
468 			DMI_MATCH(DMI_PRODUCT_NAME, "T200TA"),
469 		},
470 	},
471 	{}
472 };
473 
474 /*
475  * The _DEP method is used to identify dependencies but instead of creating
476  * device links for every handle in _DEP, only links in the following list are
477  * created. That is necessary because, in the general case, _DEP can refer to
478  * devices that might not have drivers, or that are on different buses, or where
479  * the supplier is not enumerated until after the consumer is probed.
480  */
481 static const struct lpss_device_links lpss_device_links[] = {
482 	/* CHT External sdcard slot controller depends on PMIC I2C ctrl */
483 	{"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME},
484 	/* CHT iGPU depends on PMIC I2C controller */
485 	{"808622C1", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
486 	/* BYT iGPU depends on the Embedded Controller I2C controller (UID 1) */
487 	{"80860F41", "1", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME,
488 	 i2c1_dep_missing_dmi_ids},
489 	/* BYT CR iGPU depends on PMIC I2C controller (UID 5 on CR) */
490 	{"80860F41", "5", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
491 	/* BYT iGPU depends on PMIC I2C controller (UID 7 on non CR) */
492 	{"80860F41", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
493 };
494 
495 static bool acpi_lpss_is_supplier(struct acpi_device *adev,
496 				  const struct lpss_device_links *link)
497 {
498 	return acpi_dev_hid_uid_match(adev, link->supplier_hid, link->supplier_uid);
499 }
500 
501 static bool acpi_lpss_is_consumer(struct acpi_device *adev,
502 				  const struct lpss_device_links *link)
503 {
504 	return acpi_dev_hid_uid_match(adev, link->consumer_hid, link->consumer_uid);
505 }
506 
507 struct hid_uid {
508 	const char *hid;
509 	const char *uid;
510 };
511 
512 static int match_hid_uid(struct device *dev, const void *data)
513 {
514 	struct acpi_device *adev = ACPI_COMPANION(dev);
515 	const struct hid_uid *id = data;
516 
517 	if (!adev)
518 		return 0;
519 
520 	return acpi_dev_hid_uid_match(adev, id->hid, id->uid);
521 }
522 
523 static struct device *acpi_lpss_find_device(const char *hid, const char *uid)
524 {
525 	struct device *dev;
526 
527 	struct hid_uid data = {
528 		.hid = hid,
529 		.uid = uid,
530 	};
531 
532 	dev = bus_find_device(&platform_bus_type, NULL, &data, match_hid_uid);
533 	if (dev)
534 		return dev;
535 
536 	return bus_find_device(&pci_bus_type, NULL, &data, match_hid_uid);
537 }
538 
539 static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle)
540 {
541 	struct acpi_handle_list dep_devices;
542 	acpi_status status;
543 	int i;
544 
545 	if (!acpi_has_method(adev->handle, "_DEP"))
546 		return false;
547 
548 	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
549 					 &dep_devices);
550 	if (ACPI_FAILURE(status)) {
551 		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
552 		return false;
553 	}
554 
555 	for (i = 0; i < dep_devices.count; i++) {
556 		if (dep_devices.handles[i] == handle)
557 			return true;
558 	}
559 
560 	return false;
561 }
562 
563 static void acpi_lpss_link_consumer(struct device *dev1,
564 				    const struct lpss_device_links *link)
565 {
566 	struct device *dev2;
567 
568 	dev2 = acpi_lpss_find_device(link->consumer_hid, link->consumer_uid);
569 	if (!dev2)
570 		return;
571 
572 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
573 	    || acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1)))
574 		device_link_add(dev2, dev1, link->flags);
575 
576 	put_device(dev2);
577 }
578 
579 static void acpi_lpss_link_supplier(struct device *dev1,
580 				    const struct lpss_device_links *link)
581 {
582 	struct device *dev2;
583 
584 	dev2 = acpi_lpss_find_device(link->supplier_hid, link->supplier_uid);
585 	if (!dev2)
586 		return;
587 
588 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
589 	    || 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_skip_suspend(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 		/*
1068 		 * The driver's ->suspend_late callback will be invoked by
1069 		 * acpi_lpss_do_suspend_late(), with the assumption that the
1070 		 * driver really wanted to run that code in ->suspend_noirq, but
1071 		 * it could not run after acpi_dev_suspend() and the driver
1072 		 * expected the latter to be called in the "late" phase.
1073 		 */
1074 		ret = acpi_lpss_do_suspend_late(dev);
1075 		if (ret)
1076 			return ret;
1077 	}
1078 
1079 	return acpi_subsys_suspend_noirq(dev);
1080 }
1081 
1082 static int acpi_lpss_do_resume_early(struct device *dev)
1083 {
1084 	int ret = acpi_lpss_resume(dev);
1085 
1086 	return ret ? ret : pm_generic_resume_early(dev);
1087 }
1088 
1089 static int acpi_lpss_resume_early(struct device *dev)
1090 {
1091 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1092 
1093 	if (pdata->dev_desc->resume_from_noirq)
1094 		return 0;
1095 
1096 	if (dev_pm_skip_resume(dev))
1097 		return 0;
1098 
1099 	return acpi_lpss_do_resume_early(dev);
1100 }
1101 
1102 static int acpi_lpss_resume_noirq(struct device *dev)
1103 {
1104 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1105 	int ret;
1106 
1107 	/* Follow acpi_subsys_resume_noirq(). */
1108 	if (dev_pm_skip_resume(dev))
1109 		return 0;
1110 
1111 	ret = pm_generic_resume_noirq(dev);
1112 	if (ret)
1113 		return ret;
1114 
1115 	if (!pdata->dev_desc->resume_from_noirq)
1116 		return 0;
1117 
1118 	/*
1119 	 * The driver's ->resume_early callback will be invoked by
1120 	 * acpi_lpss_do_resume_early(), with the assumption that the driver
1121 	 * really wanted to run that code in ->resume_noirq, but it could not
1122 	 * run before acpi_dev_resume() and the driver expected the latter to be
1123 	 * called in the "early" phase.
1124 	 */
1125 	return acpi_lpss_do_resume_early(dev);
1126 }
1127 
1128 static int acpi_lpss_do_restore_early(struct device *dev)
1129 {
1130 	int ret = acpi_lpss_resume(dev);
1131 
1132 	return ret ? ret : pm_generic_restore_early(dev);
1133 }
1134 
1135 static int acpi_lpss_restore_early(struct device *dev)
1136 {
1137 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1138 
1139 	if (pdata->dev_desc->resume_from_noirq)
1140 		return 0;
1141 
1142 	return acpi_lpss_do_restore_early(dev);
1143 }
1144 
1145 static int acpi_lpss_restore_noirq(struct device *dev)
1146 {
1147 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1148 	int ret;
1149 
1150 	ret = pm_generic_restore_noirq(dev);
1151 	if (ret)
1152 		return ret;
1153 
1154 	if (!pdata->dev_desc->resume_from_noirq)
1155 		return 0;
1156 
1157 	/* This is analogous to what happens in acpi_lpss_resume_noirq(). */
1158 	return acpi_lpss_do_restore_early(dev);
1159 }
1160 
1161 static int acpi_lpss_do_poweroff_late(struct device *dev)
1162 {
1163 	int ret = pm_generic_poweroff_late(dev);
1164 
1165 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1166 }
1167 
1168 static int acpi_lpss_poweroff_late(struct device *dev)
1169 {
1170 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1171 
1172 	if (dev_pm_skip_suspend(dev))
1173 		return 0;
1174 
1175 	if (pdata->dev_desc->resume_from_noirq)
1176 		return 0;
1177 
1178 	return acpi_lpss_do_poweroff_late(dev);
1179 }
1180 
1181 static int acpi_lpss_poweroff_noirq(struct device *dev)
1182 {
1183 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1184 
1185 	if (dev_pm_skip_suspend(dev))
1186 		return 0;
1187 
1188 	if (pdata->dev_desc->resume_from_noirq) {
1189 		/* This is analogous to the acpi_lpss_suspend_noirq() case. */
1190 		int ret = acpi_lpss_do_poweroff_late(dev);
1191 		if (ret)
1192 			return ret;
1193 	}
1194 
1195 	return pm_generic_poweroff_noirq(dev);
1196 }
1197 #endif /* CONFIG_PM_SLEEP */
1198 
1199 static int acpi_lpss_runtime_suspend(struct device *dev)
1200 {
1201 	int ret = pm_generic_runtime_suspend(dev);
1202 
1203 	return ret ? ret : acpi_lpss_suspend(dev, true);
1204 }
1205 
1206 static int acpi_lpss_runtime_resume(struct device *dev)
1207 {
1208 	int ret = acpi_lpss_resume(dev);
1209 
1210 	return ret ? ret : pm_generic_runtime_resume(dev);
1211 }
1212 #endif /* CONFIG_PM */
1213 
1214 static struct dev_pm_domain acpi_lpss_pm_domain = {
1215 #ifdef CONFIG_PM
1216 	.activate = acpi_lpss_activate,
1217 	.dismiss = acpi_lpss_dismiss,
1218 #endif
1219 	.ops = {
1220 #ifdef CONFIG_PM
1221 #ifdef CONFIG_PM_SLEEP
1222 		.prepare = acpi_subsys_prepare,
1223 		.complete = acpi_subsys_complete,
1224 		.suspend = acpi_subsys_suspend,
1225 		.suspend_late = acpi_lpss_suspend_late,
1226 		.suspend_noirq = acpi_lpss_suspend_noirq,
1227 		.resume_noirq = acpi_lpss_resume_noirq,
1228 		.resume_early = acpi_lpss_resume_early,
1229 		.freeze = acpi_subsys_freeze,
1230 		.poweroff = acpi_subsys_poweroff,
1231 		.poweroff_late = acpi_lpss_poweroff_late,
1232 		.poweroff_noirq = acpi_lpss_poweroff_noirq,
1233 		.restore_noirq = acpi_lpss_restore_noirq,
1234 		.restore_early = acpi_lpss_restore_early,
1235 #endif
1236 		.runtime_suspend = acpi_lpss_runtime_suspend,
1237 		.runtime_resume = acpi_lpss_runtime_resume,
1238 #endif
1239 	},
1240 };
1241 
1242 static int acpi_lpss_platform_notify(struct notifier_block *nb,
1243 				     unsigned long action, void *data)
1244 {
1245 	struct platform_device *pdev = to_platform_device(data);
1246 	struct lpss_private_data *pdata;
1247 	struct acpi_device *adev;
1248 	const struct acpi_device_id *id;
1249 
1250 	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
1251 	if (!id || !id->driver_data)
1252 		return 0;
1253 
1254 	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
1255 		return 0;
1256 
1257 	pdata = acpi_driver_data(adev);
1258 	if (!pdata)
1259 		return 0;
1260 
1261 	if (pdata->mmio_base &&
1262 	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
1263 		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
1264 		return 0;
1265 	}
1266 
1267 	switch (action) {
1268 	case BUS_NOTIFY_BIND_DRIVER:
1269 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1270 		break;
1271 	case BUS_NOTIFY_DRIVER_NOT_BOUND:
1272 	case BUS_NOTIFY_UNBOUND_DRIVER:
1273 		dev_pm_domain_set(&pdev->dev, NULL);
1274 		break;
1275 	case BUS_NOTIFY_ADD_DEVICE:
1276 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1277 		if (pdata->dev_desc->flags & LPSS_LTR)
1278 			return sysfs_create_group(&pdev->dev.kobj,
1279 						  &lpss_attr_group);
1280 		break;
1281 	case BUS_NOTIFY_DEL_DEVICE:
1282 		if (pdata->dev_desc->flags & LPSS_LTR)
1283 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
1284 		dev_pm_domain_set(&pdev->dev, NULL);
1285 		break;
1286 	default:
1287 		break;
1288 	}
1289 
1290 	return 0;
1291 }
1292 
1293 static struct notifier_block acpi_lpss_nb = {
1294 	.notifier_call = acpi_lpss_platform_notify,
1295 };
1296 
1297 static void acpi_lpss_bind(struct device *dev)
1298 {
1299 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1300 
1301 	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
1302 		return;
1303 
1304 	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
1305 		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
1306 	else
1307 		dev_err(dev, "MMIO size insufficient to access LTR\n");
1308 }
1309 
1310 static void acpi_lpss_unbind(struct device *dev)
1311 {
1312 	dev->power.set_latency_tolerance = NULL;
1313 }
1314 
1315 static struct acpi_scan_handler lpss_handler = {
1316 	.ids = acpi_lpss_device_ids,
1317 	.attach = acpi_lpss_create_device,
1318 	.bind = acpi_lpss_bind,
1319 	.unbind = acpi_lpss_unbind,
1320 };
1321 
1322 void __init acpi_lpss_init(void)
1323 {
1324 	const struct x86_cpu_id *id;
1325 	int ret;
1326 
1327 	ret = lpt_clk_init();
1328 	if (ret)
1329 		return;
1330 
1331 	id = x86_match_cpu(lpss_cpu_ids);
1332 	if (id)
1333 		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
1334 
1335 	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
1336 	acpi_scan_add_handler(&lpss_handler);
1337 }
1338 
1339 #else
1340 
1341 static struct acpi_scan_handler lpss_handler = {
1342 	.ids = acpi_lpss_device_ids,
1343 };
1344 
1345 void __init acpi_lpss_init(void)
1346 {
1347 	acpi_scan_add_handler(&lpss_handler);
1348 }
1349 
1350 #endif /* CONFIG_X86_INTEL_LPSS */
1351