xref: /openbmc/linux/drivers/acpi/acpi_lpss.c (revision ee8ec048)
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 #ifdef CONFIG_X86_INTEL_LPSS
30 
31 #include <asm/cpu_device_id.h>
32 #include <asm/intel-family.h>
33 #include <asm/iosf_mbi.h>
34 
35 #define LPSS_ADDR(desc) ((unsigned long)&desc)
36 
37 #define LPSS_CLK_SIZE	0x04
38 #define LPSS_LTR_SIZE	0x18
39 
40 /* Offsets relative to LPSS_PRIVATE_OFFSET */
41 #define LPSS_CLK_DIVIDER_DEF_MASK	(BIT(1) | BIT(16))
42 #define LPSS_RESETS			0x04
43 #define LPSS_RESETS_RESET_FUNC		BIT(0)
44 #define LPSS_RESETS_RESET_APB		BIT(1)
45 #define LPSS_GENERAL			0x08
46 #define LPSS_GENERAL_LTR_MODE_SW	BIT(2)
47 #define LPSS_GENERAL_UART_RTS_OVRD	BIT(3)
48 #define LPSS_SW_LTR			0x10
49 #define LPSS_AUTO_LTR			0x14
50 #define LPSS_LTR_SNOOP_REQ		BIT(15)
51 #define LPSS_LTR_SNOOP_MASK		0x0000FFFF
52 #define LPSS_LTR_SNOOP_LAT_1US		0x800
53 #define LPSS_LTR_SNOOP_LAT_32US		0xC00
54 #define LPSS_LTR_SNOOP_LAT_SHIFT	5
55 #define LPSS_LTR_SNOOP_LAT_CUTOFF	3000
56 #define LPSS_LTR_MAX_VAL		0x3FF
57 #define LPSS_TX_INT			0x20
58 #define LPSS_TX_INT_MASK		BIT(1)
59 
60 #define LPSS_PRV_REG_COUNT		9
61 
62 /* LPSS Flags */
63 #define LPSS_CLK			BIT(0)
64 #define LPSS_CLK_GATE			BIT(1)
65 #define LPSS_CLK_DIVIDER		BIT(2)
66 #define LPSS_LTR			BIT(3)
67 #define LPSS_SAVE_CTX			BIT(4)
68 /*
69  * For some devices the DSDT AML code for another device turns off the device
70  * before our suspend handler runs, causing us to read/save all 1-s (0xffffffff)
71  * as ctx register values.
72  * Luckily these devices always use the same ctx register values, so we can
73  * work around this by saving the ctx registers once on activation.
74  */
75 #define LPSS_SAVE_CTX_ONCE		BIT(5)
76 #define LPSS_NO_D3_DELAY		BIT(6)
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_soc_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 	pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup));
176 }
177 
178 #define LPSS_I2C_ENABLE			0x6c
179 
180 static void byt_i2c_setup(struct lpss_private_data *pdata)
181 {
182 	const char *uid_str = acpi_device_uid(pdata->adev);
183 	acpi_handle handle = pdata->adev->handle;
184 	unsigned long long shared_host = 0;
185 	acpi_status status;
186 	long uid = 0;
187 
188 	/* Expected to always be true, but better safe then sorry */
189 	if (uid_str && !kstrtol(uid_str, 10, &uid) && uid) {
190 		/* Detect I2C bus shared with PUNIT and ignore its d3 status */
191 		status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
192 		if (ACPI_SUCCESS(status) && shared_host)
193 			pmc_atom_d3_mask &= ~(BIT_LPSS2_F1_I2C1 << (uid - 1));
194 	}
195 
196 	lpss_deassert_reset(pdata);
197 
198 	if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
199 		pdata->fixed_clk_rate = 133000000;
200 
201 	writel(0, pdata->mmio_base + LPSS_I2C_ENABLE);
202 }
203 
204 /* BSW PWM used for backlight control by the i915 driver */
205 static struct pwm_lookup bsw_pwm_lookup[] = {
206 	PWM_LOOKUP_WITH_MODULE("80862288:00", 0, "0000:00:02.0",
207 			       "pwm_soc_backlight", 0, PWM_POLARITY_NORMAL,
208 			       "pwm-lpss-platform"),
209 };
210 
211 static void bsw_pwm_setup(struct lpss_private_data *pdata)
212 {
213 	struct acpi_device *adev = pdata->adev;
214 
215 	/* Only call pwm_add_table for the first PWM controller */
216 	if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
217 		return;
218 
219 	pwm_add_table(bsw_pwm_lookup, ARRAY_SIZE(bsw_pwm_lookup));
220 }
221 
222 static const struct lpss_device_desc lpt_dev_desc = {
223 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR
224 			| LPSS_SAVE_CTX,
225 	.prv_offset = 0x800,
226 };
227 
228 static const struct lpss_device_desc lpt_i2c_dev_desc = {
229 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR | LPSS_SAVE_CTX,
230 	.prv_offset = 0x800,
231 };
232 
233 static struct property_entry uart_properties[] = {
234 	PROPERTY_ENTRY_U32("reg-io-width", 4),
235 	PROPERTY_ENTRY_U32("reg-shift", 2),
236 	PROPERTY_ENTRY_BOOL("snps,uart-16550-compatible"),
237 	{ },
238 };
239 
240 static const struct lpss_device_desc lpt_uart_dev_desc = {
241 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR
242 			| LPSS_SAVE_CTX,
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_ONCE | LPSS_NO_D3_DELAY,
263 	.prv_offset = 0x800,
264 	.setup = bsw_pwm_setup,
265 	.resume_from_noirq = true,
266 };
267 
268 static const struct lpss_device_desc byt_uart_dev_desc = {
269 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
270 	.clk_con_id = "baudclk",
271 	.prv_offset = 0x800,
272 	.setup = lpss_uart_setup,
273 	.properties = uart_properties,
274 };
275 
276 static const struct lpss_device_desc bsw_uart_dev_desc = {
277 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
278 			| LPSS_NO_D3_DELAY,
279 	.clk_con_id = "baudclk",
280 	.prv_offset = 0x800,
281 	.setup = lpss_uart_setup,
282 	.properties = uart_properties,
283 };
284 
285 static const struct lpss_device_desc byt_spi_dev_desc = {
286 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
287 	.prv_offset = 0x400,
288 };
289 
290 static const struct lpss_device_desc byt_sdio_dev_desc = {
291 	.flags = LPSS_CLK,
292 };
293 
294 static const struct lpss_device_desc byt_i2c_dev_desc = {
295 	.flags = LPSS_CLK | LPSS_SAVE_CTX,
296 	.prv_offset = 0x800,
297 	.setup = byt_i2c_setup,
298 	.resume_from_noirq = true,
299 };
300 
301 static const struct lpss_device_desc bsw_i2c_dev_desc = {
302 	.flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
303 	.prv_offset = 0x800,
304 	.setup = byt_i2c_setup,
305 	.resume_from_noirq = true,
306 };
307 
308 static const struct lpss_device_desc bsw_spi_dev_desc = {
309 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
310 			| LPSS_NO_D3_DELAY,
311 	.prv_offset = 0x400,
312 	.setup = lpss_deassert_reset,
313 };
314 
315 static const struct x86_cpu_id lpss_cpu_ids[] = {
316 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT,	NULL),
317 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT,	NULL),
318 	{}
319 };
320 
321 #else
322 
323 #define LPSS_ADDR(desc) (0UL)
324 
325 #endif /* CONFIG_X86_INTEL_LPSS */
326 
327 static const struct acpi_device_id acpi_lpss_device_ids[] = {
328 	/* Generic LPSS devices */
329 	{ "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
330 
331 	/* Lynxpoint LPSS devices */
332 	{ "INT33C0", LPSS_ADDR(lpt_dev_desc) },
333 	{ "INT33C1", LPSS_ADDR(lpt_dev_desc) },
334 	{ "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
335 	{ "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
336 	{ "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
337 	{ "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
338 	{ "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
339 	{ "INT33C7", },
340 
341 	/* BayTrail LPSS devices */
342 	{ "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
343 	{ "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
344 	{ "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
345 	{ "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
346 	{ "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
347 	{ "INT33B2", },
348 	{ "INT33FC", },
349 
350 	/* Braswell LPSS devices */
351 	{ "80862286", LPSS_ADDR(lpss_dma_desc) },
352 	{ "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
353 	{ "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
354 	{ "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
355 	{ "808622C0", LPSS_ADDR(lpss_dma_desc) },
356 	{ "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
357 
358 	/* Broadwell LPSS devices */
359 	{ "INT3430", LPSS_ADDR(lpt_dev_desc) },
360 	{ "INT3431", LPSS_ADDR(lpt_dev_desc) },
361 	{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
362 	{ "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
363 	{ "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
364 	{ "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
365 	{ "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
366 	{ "INT3437", },
367 
368 	/* Wildcat Point LPSS devices */
369 	{ "INT3438", LPSS_ADDR(lpt_dev_desc) },
370 
371 	{ }
372 };
373 
374 #ifdef CONFIG_X86_INTEL_LPSS
375 
376 static int is_memory(struct acpi_resource *res, void *not_used)
377 {
378 	struct resource r;
379 
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-lpss-atom",
389 						       PLATFORM_DEVID_NONE,
390 						       NULL, 0);
391 }
392 
393 static int register_device_clock(struct acpi_device *adev,
394 				 struct lpss_private_data *pdata)
395 {
396 	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
397 	const char *devname = dev_name(&adev->dev);
398 	struct clk *clk;
399 	struct lpss_clk_data *clk_data;
400 	const char *parent, *clk_name;
401 	void __iomem *prv_base;
402 
403 	if (!lpss_clk_dev)
404 		lpt_register_clock_device();
405 
406 	clk_data = platform_get_drvdata(lpss_clk_dev);
407 	if (!clk_data)
408 		return -ENODEV;
409 	clk = clk_data->clk;
410 
411 	if (!pdata->mmio_base
412 	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
413 		return -ENODATA;
414 
415 	parent = clk_data->name;
416 	prv_base = pdata->mmio_base + dev_desc->prv_offset;
417 
418 	if (pdata->fixed_clk_rate) {
419 		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
420 					      pdata->fixed_clk_rate);
421 		goto out;
422 	}
423 
424 	if (dev_desc->flags & LPSS_CLK_GATE) {
425 		clk = clk_register_gate(NULL, devname, parent, 0,
426 					prv_base, 0, 0, NULL);
427 		parent = devname;
428 	}
429 
430 	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
431 		/* Prevent division by zero */
432 		if (!readl(prv_base))
433 			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
434 
435 		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
436 		if (!clk_name)
437 			return -ENOMEM;
438 		clk = clk_register_fractional_divider(NULL, clk_name, parent,
439 						      CLK_FRAC_DIVIDER_POWER_OF_TWO_PS,
440 						      prv_base, 1, 15, 16, 15, 0, NULL);
441 		parent = clk_name;
442 
443 		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
444 		if (!clk_name) {
445 			kfree(parent);
446 			return -ENOMEM;
447 		}
448 		clk = clk_register_gate(NULL, clk_name, parent,
449 					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
450 					prv_base, 31, 0, NULL);
451 		kfree(parent);
452 		kfree(clk_name);
453 	}
454 out:
455 	if (IS_ERR(clk))
456 		return PTR_ERR(clk);
457 
458 	pdata->clk = clk;
459 	clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
460 	return 0;
461 }
462 
463 struct lpss_device_links {
464 	const char *supplier_hid;
465 	const char *supplier_uid;
466 	const char *consumer_hid;
467 	const char *consumer_uid;
468 	u32 flags;
469 	const struct dmi_system_id *dep_missing_ids;
470 };
471 
472 /* Please keep this list sorted alphabetically by vendor and model */
473 static const struct dmi_system_id i2c1_dep_missing_dmi_ids[] = {
474 	{
475 		.matches = {
476 			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
477 			DMI_MATCH(DMI_PRODUCT_NAME, "T200TA"),
478 		},
479 	},
480 	{}
481 };
482 
483 /*
484  * The _DEP method is used to identify dependencies but instead of creating
485  * device links for every handle in _DEP, only links in the following list are
486  * created. That is necessary because, in the general case, _DEP can refer to
487  * devices that might not have drivers, or that are on different buses, or where
488  * the supplier is not enumerated until after the consumer is probed.
489  */
490 static const struct lpss_device_links lpss_device_links[] = {
491 	/* CHT External sdcard slot controller depends on PMIC I2C ctrl */
492 	{"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME},
493 	/* CHT iGPU depends on PMIC I2C controller */
494 	{"808622C1", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
495 	/* BYT iGPU depends on the Embedded Controller I2C controller (UID 1) */
496 	{"80860F41", "1", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME,
497 	 i2c1_dep_missing_dmi_ids},
498 	/* BYT CR iGPU depends on PMIC I2C controller (UID 5 on CR) */
499 	{"80860F41", "5", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
500 	/* BYT iGPU depends on PMIC I2C controller (UID 7 on non CR) */
501 	{"80860F41", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
502 };
503 
504 static bool acpi_lpss_is_supplier(struct acpi_device *adev,
505 				  const struct lpss_device_links *link)
506 {
507 	return acpi_dev_hid_uid_match(adev, link->supplier_hid, link->supplier_uid);
508 }
509 
510 static bool acpi_lpss_is_consumer(struct acpi_device *adev,
511 				  const struct lpss_device_links *link)
512 {
513 	return acpi_dev_hid_uid_match(adev, link->consumer_hid, link->consumer_uid);
514 }
515 
516 struct hid_uid {
517 	const char *hid;
518 	const char *uid;
519 };
520 
521 static int match_hid_uid(struct device *dev, const void *data)
522 {
523 	struct acpi_device *adev = ACPI_COMPANION(dev);
524 	const struct hid_uid *id = data;
525 
526 	if (!adev)
527 		return 0;
528 
529 	return acpi_dev_hid_uid_match(adev, id->hid, id->uid);
530 }
531 
532 static struct device *acpi_lpss_find_device(const char *hid, const char *uid)
533 {
534 	struct device *dev;
535 
536 	struct hid_uid data = {
537 		.hid = hid,
538 		.uid = uid,
539 	};
540 
541 	dev = bus_find_device(&platform_bus_type, NULL, &data, match_hid_uid);
542 	if (dev)
543 		return dev;
544 
545 	return bus_find_device(&pci_bus_type, NULL, &data, match_hid_uid);
546 }
547 
548 static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle)
549 {
550 	struct acpi_handle_list dep_devices;
551 	acpi_status status;
552 	int i;
553 
554 	if (!acpi_has_method(adev->handle, "_DEP"))
555 		return false;
556 
557 	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
558 					 &dep_devices);
559 	if (ACPI_FAILURE(status)) {
560 		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
561 		return false;
562 	}
563 
564 	for (i = 0; i < dep_devices.count; i++) {
565 		if (dep_devices.handles[i] == handle)
566 			return true;
567 	}
568 
569 	return false;
570 }
571 
572 static void acpi_lpss_link_consumer(struct device *dev1,
573 				    const struct lpss_device_links *link)
574 {
575 	struct device *dev2;
576 
577 	dev2 = acpi_lpss_find_device(link->consumer_hid, link->consumer_uid);
578 	if (!dev2)
579 		return;
580 
581 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
582 	    || acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1)))
583 		device_link_add(dev2, dev1, link->flags);
584 
585 	put_device(dev2);
586 }
587 
588 static void acpi_lpss_link_supplier(struct device *dev1,
589 				    const struct lpss_device_links *link)
590 {
591 	struct device *dev2;
592 
593 	dev2 = acpi_lpss_find_device(link->supplier_hid, link->supplier_uid);
594 	if (!dev2)
595 		return;
596 
597 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
598 	    || acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2)))
599 		device_link_add(dev1, dev2, link->flags);
600 
601 	put_device(dev2);
602 }
603 
604 static void acpi_lpss_create_device_links(struct acpi_device *adev,
605 					  struct platform_device *pdev)
606 {
607 	int i;
608 
609 	for (i = 0; i < ARRAY_SIZE(lpss_device_links); i++) {
610 		const struct lpss_device_links *link = &lpss_device_links[i];
611 
612 		if (acpi_lpss_is_supplier(adev, link))
613 			acpi_lpss_link_consumer(&pdev->dev, link);
614 
615 		if (acpi_lpss_is_consumer(adev, link))
616 			acpi_lpss_link_supplier(&pdev->dev, link);
617 	}
618 }
619 
620 static int acpi_lpss_create_device(struct acpi_device *adev,
621 				   const struct acpi_device_id *id)
622 {
623 	const struct lpss_device_desc *dev_desc;
624 	struct lpss_private_data *pdata;
625 	struct resource_entry *rentry;
626 	struct list_head resource_list;
627 	struct platform_device *pdev;
628 	int ret;
629 
630 	dev_desc = (const struct lpss_device_desc *)id->driver_data;
631 	if (!dev_desc) {
632 		pdev = acpi_create_platform_device(adev, NULL);
633 		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
634 	}
635 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
636 	if (!pdata)
637 		return -ENOMEM;
638 
639 	INIT_LIST_HEAD(&resource_list);
640 	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
641 	if (ret < 0)
642 		goto err_out;
643 
644 	list_for_each_entry(rentry, &resource_list, node)
645 		if (resource_type(rentry->res) == IORESOURCE_MEM) {
646 			if (dev_desc->prv_size_override)
647 				pdata->mmio_size = dev_desc->prv_size_override;
648 			else
649 				pdata->mmio_size = resource_size(rentry->res);
650 			pdata->mmio_base = ioremap(rentry->res->start,
651 						   pdata->mmio_size);
652 			break;
653 		}
654 
655 	acpi_dev_free_resource_list(&resource_list);
656 
657 	if (!pdata->mmio_base) {
658 		/* Avoid acpi_bus_attach() instantiating a pdev for this dev. */
659 		adev->pnp.type.platform_id = 0;
660 		/* Skip the device, but continue the namespace scan. */
661 		ret = 0;
662 		goto err_out;
663 	}
664 
665 	pdata->adev = adev;
666 	pdata->dev_desc = dev_desc;
667 
668 	if (dev_desc->setup)
669 		dev_desc->setup(pdata);
670 
671 	if (dev_desc->flags & LPSS_CLK) {
672 		ret = register_device_clock(adev, pdata);
673 		if (ret) {
674 			/* Skip the device, but continue the namespace scan. */
675 			ret = 0;
676 			goto err_out;
677 		}
678 	}
679 
680 	/*
681 	 * This works around a known issue in ACPI tables where LPSS devices
682 	 * have _PS0 and _PS3 without _PSC (and no power resources), so
683 	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
684 	 */
685 	acpi_device_fix_up_power(adev);
686 
687 	adev->driver_data = pdata;
688 	pdev = acpi_create_platform_device(adev, dev_desc->properties);
689 	if (!IS_ERR_OR_NULL(pdev)) {
690 		acpi_lpss_create_device_links(adev, pdev);
691 		return 1;
692 	}
693 
694 	ret = PTR_ERR(pdev);
695 	adev->driver_data = NULL;
696 
697  err_out:
698 	kfree(pdata);
699 	return ret;
700 }
701 
702 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
703 {
704 	return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
705 }
706 
707 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
708 			     unsigned int reg)
709 {
710 	writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
711 }
712 
713 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
714 {
715 	struct acpi_device *adev = ACPI_COMPANION(dev);
716 	struct lpss_private_data *pdata;
717 	unsigned long flags;
718 	int ret;
719 
720 	if (WARN_ON(!adev))
721 		return -ENODEV;
722 
723 	spin_lock_irqsave(&dev->power.lock, flags);
724 	if (pm_runtime_suspended(dev)) {
725 		ret = -EAGAIN;
726 		goto out;
727 	}
728 	pdata = acpi_driver_data(adev);
729 	if (WARN_ON(!pdata || !pdata->mmio_base)) {
730 		ret = -ENODEV;
731 		goto out;
732 	}
733 	*val = __lpss_reg_read(pdata, reg);
734 	ret = 0;
735 
736  out:
737 	spin_unlock_irqrestore(&dev->power.lock, flags);
738 	return ret;
739 }
740 
741 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
742 			     char *buf)
743 {
744 	u32 ltr_value = 0;
745 	unsigned int reg;
746 	int ret;
747 
748 	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
749 	ret = lpss_reg_read(dev, reg, &ltr_value);
750 	if (ret)
751 		return ret;
752 
753 	return sysfs_emit(buf, "%08x\n", ltr_value);
754 }
755 
756 static ssize_t lpss_ltr_mode_show(struct device *dev,
757 				  struct device_attribute *attr, char *buf)
758 {
759 	u32 ltr_mode = 0;
760 	char *outstr;
761 	int ret;
762 
763 	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
764 	if (ret)
765 		return ret;
766 
767 	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
768 	return sprintf(buf, "%s\n", outstr);
769 }
770 
771 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
772 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
773 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
774 
775 static struct attribute *lpss_attrs[] = {
776 	&dev_attr_auto_ltr.attr,
777 	&dev_attr_sw_ltr.attr,
778 	&dev_attr_ltr_mode.attr,
779 	NULL,
780 };
781 
782 static const struct attribute_group lpss_attr_group = {
783 	.attrs = lpss_attrs,
784 	.name = "lpss_ltr",
785 };
786 
787 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
788 {
789 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
790 	u32 ltr_mode, ltr_val;
791 
792 	ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
793 	if (val < 0) {
794 		if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
795 			ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
796 			__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
797 		}
798 		return;
799 	}
800 	ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
801 	if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
802 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
803 		val = LPSS_LTR_MAX_VAL;
804 	} else if (val > LPSS_LTR_MAX_VAL) {
805 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
806 		val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
807 	} else {
808 		ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
809 	}
810 	ltr_val |= val;
811 	__lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
812 	if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
813 		ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
814 		__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
815 	}
816 }
817 
818 #ifdef CONFIG_PM
819 /**
820  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
821  * @dev: LPSS device
822  * @pdata: pointer to the private data of the LPSS device
823  *
824  * Most LPSS devices have private registers which may loose their context when
825  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
826  * prv_reg_ctx array.
827  */
828 static void acpi_lpss_save_ctx(struct device *dev,
829 			       struct lpss_private_data *pdata)
830 {
831 	unsigned int i;
832 
833 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
834 		unsigned long offset = i * sizeof(u32);
835 
836 		pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
837 		dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
838 			pdata->prv_reg_ctx[i], offset);
839 	}
840 }
841 
842 /**
843  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
844  * @dev: LPSS device
845  * @pdata: pointer to the private data of the LPSS device
846  *
847  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
848  */
849 static void acpi_lpss_restore_ctx(struct device *dev,
850 				  struct lpss_private_data *pdata)
851 {
852 	unsigned int i;
853 
854 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
855 		unsigned long offset = i * sizeof(u32);
856 
857 		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
858 		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
859 			pdata->prv_reg_ctx[i], offset);
860 	}
861 }
862 
863 static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
864 {
865 	/*
866 	 * The following delay is needed or the subsequent write operations may
867 	 * fail. The LPSS devices are actually PCI devices and the PCI spec
868 	 * expects 10ms delay before the device can be accessed after D3 to D0
869 	 * transition. However some platforms like BSW does not need this delay.
870 	 */
871 	unsigned int delay = 10;	/* default 10ms delay */
872 
873 	if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
874 		delay = 0;
875 
876 	msleep(delay);
877 }
878 
879 static int acpi_lpss_activate(struct device *dev)
880 {
881 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
882 	int ret;
883 
884 	ret = acpi_dev_resume(dev);
885 	if (ret)
886 		return ret;
887 
888 	acpi_lpss_d3_to_d0_delay(pdata);
889 
890 	/*
891 	 * This is called only on ->probe() stage where a device is either in
892 	 * known state defined by BIOS or most likely powered off. Due to this
893 	 * we have to deassert reset line to be sure that ->probe() will
894 	 * recognize the device.
895 	 */
896 	if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE))
897 		lpss_deassert_reset(pdata);
898 
899 #ifdef CONFIG_PM
900 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX_ONCE)
901 		acpi_lpss_save_ctx(dev, pdata);
902 #endif
903 
904 	return 0;
905 }
906 
907 static void acpi_lpss_dismiss(struct device *dev)
908 {
909 	acpi_dev_suspend(dev, false);
910 }
911 
912 /* IOSF SB for LPSS island */
913 #define LPSS_IOSF_UNIT_LPIOEP		0xA0
914 #define LPSS_IOSF_UNIT_LPIO1		0xAB
915 #define LPSS_IOSF_UNIT_LPIO2		0xAC
916 
917 #define LPSS_IOSF_PMCSR			0x84
918 #define LPSS_PMCSR_D0			0
919 #define LPSS_PMCSR_D3hot		3
920 #define LPSS_PMCSR_Dx_MASK		GENMASK(1, 0)
921 
922 #define LPSS_IOSF_GPIODEF0		0x154
923 #define LPSS_GPIODEF0_DMA1_D3		BIT(2)
924 #define LPSS_GPIODEF0_DMA2_D3		BIT(3)
925 #define LPSS_GPIODEF0_DMA_D3_MASK	GENMASK(3, 2)
926 #define LPSS_GPIODEF0_DMA_LLP		BIT(13)
927 
928 static DEFINE_MUTEX(lpss_iosf_mutex);
929 static bool lpss_iosf_d3_entered = true;
930 
931 static void lpss_iosf_enter_d3_state(void)
932 {
933 	u32 value1 = 0;
934 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
935 	u32 value2 = LPSS_PMCSR_D3hot;
936 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
937 	/*
938 	 * PMC provides an information about actual status of the LPSS devices.
939 	 * Here we read the values related to LPSS power island, i.e. LPSS
940 	 * devices, excluding both LPSS DMA controllers, along with SCC domain.
941 	 */
942 	u32 func_dis, d3_sts_0, pmc_status;
943 	int ret;
944 
945 	ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
946 	if (ret)
947 		return;
948 
949 	mutex_lock(&lpss_iosf_mutex);
950 
951 	ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
952 	if (ret)
953 		goto exit;
954 
955 	/*
956 	 * Get the status of entire LPSS power island per device basis.
957 	 * Shutdown both LPSS DMA controllers if and only if all other devices
958 	 * are already in D3hot.
959 	 */
960 	pmc_status = (~(d3_sts_0 | func_dis)) & pmc_atom_d3_mask;
961 	if (pmc_status)
962 		goto exit;
963 
964 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
965 			LPSS_IOSF_PMCSR, value2, mask2);
966 
967 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
968 			LPSS_IOSF_PMCSR, value2, mask2);
969 
970 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
971 			LPSS_IOSF_GPIODEF0, value1, mask1);
972 
973 	lpss_iosf_d3_entered = true;
974 
975 exit:
976 	mutex_unlock(&lpss_iosf_mutex);
977 }
978 
979 static void lpss_iosf_exit_d3_state(void)
980 {
981 	u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3 |
982 		     LPSS_GPIODEF0_DMA_LLP;
983 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
984 	u32 value2 = LPSS_PMCSR_D0;
985 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
986 
987 	mutex_lock(&lpss_iosf_mutex);
988 
989 	if (!lpss_iosf_d3_entered)
990 		goto exit;
991 
992 	lpss_iosf_d3_entered = false;
993 
994 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
995 			LPSS_IOSF_GPIODEF0, value1, mask1);
996 
997 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
998 			LPSS_IOSF_PMCSR, value2, mask2);
999 
1000 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
1001 			LPSS_IOSF_PMCSR, value2, mask2);
1002 
1003 exit:
1004 	mutex_unlock(&lpss_iosf_mutex);
1005 }
1006 
1007 static int acpi_lpss_suspend(struct device *dev, bool wakeup)
1008 {
1009 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1010 	int ret;
1011 
1012 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
1013 		acpi_lpss_save_ctx(dev, pdata);
1014 
1015 	ret = acpi_dev_suspend(dev, wakeup);
1016 
1017 	/*
1018 	 * This call must be last in the sequence, otherwise PMC will return
1019 	 * wrong status for devices being about to be powered off. See
1020 	 * lpss_iosf_enter_d3_state() for further information.
1021 	 */
1022 	if (acpi_target_system_state() == ACPI_STATE_S0 &&
1023 	    lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1024 		lpss_iosf_enter_d3_state();
1025 
1026 	return ret;
1027 }
1028 
1029 static int acpi_lpss_resume(struct device *dev)
1030 {
1031 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1032 	int ret;
1033 
1034 	/*
1035 	 * This call is kept first to be in symmetry with
1036 	 * acpi_lpss_runtime_suspend() one.
1037 	 */
1038 	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1039 		lpss_iosf_exit_d3_state();
1040 
1041 	ret = acpi_dev_resume(dev);
1042 	if (ret)
1043 		return ret;
1044 
1045 	acpi_lpss_d3_to_d0_delay(pdata);
1046 
1047 	if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE))
1048 		acpi_lpss_restore_ctx(dev, pdata);
1049 
1050 	return 0;
1051 }
1052 
1053 #ifdef CONFIG_PM_SLEEP
1054 static int acpi_lpss_do_suspend_late(struct device *dev)
1055 {
1056 	int ret;
1057 
1058 	if (dev_pm_skip_suspend(dev))
1059 		return 0;
1060 
1061 	ret = pm_generic_suspend_late(dev);
1062 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1063 }
1064 
1065 static int acpi_lpss_suspend_late(struct device *dev)
1066 {
1067 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1068 
1069 	if (pdata->dev_desc->resume_from_noirq)
1070 		return 0;
1071 
1072 	return acpi_lpss_do_suspend_late(dev);
1073 }
1074 
1075 static int acpi_lpss_suspend_noirq(struct device *dev)
1076 {
1077 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1078 	int ret;
1079 
1080 	if (pdata->dev_desc->resume_from_noirq) {
1081 		/*
1082 		 * The driver's ->suspend_late callback will be invoked by
1083 		 * acpi_lpss_do_suspend_late(), with the assumption that the
1084 		 * driver really wanted to run that code in ->suspend_noirq, but
1085 		 * it could not run after acpi_dev_suspend() and the driver
1086 		 * expected the latter to be called in the "late" phase.
1087 		 */
1088 		ret = acpi_lpss_do_suspend_late(dev);
1089 		if (ret)
1090 			return ret;
1091 	}
1092 
1093 	return acpi_subsys_suspend_noirq(dev);
1094 }
1095 
1096 static int acpi_lpss_do_resume_early(struct device *dev)
1097 {
1098 	int ret = acpi_lpss_resume(dev);
1099 
1100 	return ret ? ret : pm_generic_resume_early(dev);
1101 }
1102 
1103 static int acpi_lpss_resume_early(struct device *dev)
1104 {
1105 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1106 
1107 	if (pdata->dev_desc->resume_from_noirq)
1108 		return 0;
1109 
1110 	if (dev_pm_skip_resume(dev))
1111 		return 0;
1112 
1113 	return acpi_lpss_do_resume_early(dev);
1114 }
1115 
1116 static int acpi_lpss_resume_noirq(struct device *dev)
1117 {
1118 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1119 	int ret;
1120 
1121 	/* Follow acpi_subsys_resume_noirq(). */
1122 	if (dev_pm_skip_resume(dev))
1123 		return 0;
1124 
1125 	ret = pm_generic_resume_noirq(dev);
1126 	if (ret)
1127 		return ret;
1128 
1129 	if (!pdata->dev_desc->resume_from_noirq)
1130 		return 0;
1131 
1132 	/*
1133 	 * The driver's ->resume_early callback will be invoked by
1134 	 * acpi_lpss_do_resume_early(), with the assumption that the driver
1135 	 * really wanted to run that code in ->resume_noirq, but it could not
1136 	 * run before acpi_dev_resume() and the driver expected the latter to be
1137 	 * called in the "early" phase.
1138 	 */
1139 	return acpi_lpss_do_resume_early(dev);
1140 }
1141 
1142 static int acpi_lpss_do_restore_early(struct device *dev)
1143 {
1144 	int ret = acpi_lpss_resume(dev);
1145 
1146 	return ret ? ret : pm_generic_restore_early(dev);
1147 }
1148 
1149 static int acpi_lpss_restore_early(struct device *dev)
1150 {
1151 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1152 
1153 	if (pdata->dev_desc->resume_from_noirq)
1154 		return 0;
1155 
1156 	return acpi_lpss_do_restore_early(dev);
1157 }
1158 
1159 static int acpi_lpss_restore_noirq(struct device *dev)
1160 {
1161 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1162 	int ret;
1163 
1164 	ret = pm_generic_restore_noirq(dev);
1165 	if (ret)
1166 		return ret;
1167 
1168 	if (!pdata->dev_desc->resume_from_noirq)
1169 		return 0;
1170 
1171 	/* This is analogous to what happens in acpi_lpss_resume_noirq(). */
1172 	return acpi_lpss_do_restore_early(dev);
1173 }
1174 
1175 static int acpi_lpss_do_poweroff_late(struct device *dev)
1176 {
1177 	int ret = pm_generic_poweroff_late(dev);
1178 
1179 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1180 }
1181 
1182 static int acpi_lpss_poweroff_late(struct device *dev)
1183 {
1184 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1185 
1186 	if (dev_pm_skip_suspend(dev))
1187 		return 0;
1188 
1189 	if (pdata->dev_desc->resume_from_noirq)
1190 		return 0;
1191 
1192 	return acpi_lpss_do_poweroff_late(dev);
1193 }
1194 
1195 static int acpi_lpss_poweroff_noirq(struct device *dev)
1196 {
1197 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1198 
1199 	if (dev_pm_skip_suspend(dev))
1200 		return 0;
1201 
1202 	if (pdata->dev_desc->resume_from_noirq) {
1203 		/* This is analogous to the acpi_lpss_suspend_noirq() case. */
1204 		int ret = acpi_lpss_do_poweroff_late(dev);
1205 
1206 		if (ret)
1207 			return ret;
1208 	}
1209 
1210 	return pm_generic_poweroff_noirq(dev);
1211 }
1212 #endif /* CONFIG_PM_SLEEP */
1213 
1214 static int acpi_lpss_runtime_suspend(struct device *dev)
1215 {
1216 	int ret = pm_generic_runtime_suspend(dev);
1217 
1218 	return ret ? ret : acpi_lpss_suspend(dev, true);
1219 }
1220 
1221 static int acpi_lpss_runtime_resume(struct device *dev)
1222 {
1223 	int ret = acpi_lpss_resume(dev);
1224 
1225 	return ret ? ret : pm_generic_runtime_resume(dev);
1226 }
1227 #endif /* CONFIG_PM */
1228 
1229 static struct dev_pm_domain acpi_lpss_pm_domain = {
1230 #ifdef CONFIG_PM
1231 	.activate = acpi_lpss_activate,
1232 	.dismiss = acpi_lpss_dismiss,
1233 #endif
1234 	.ops = {
1235 #ifdef CONFIG_PM
1236 #ifdef CONFIG_PM_SLEEP
1237 		.prepare = acpi_subsys_prepare,
1238 		.complete = acpi_subsys_complete,
1239 		.suspend = acpi_subsys_suspend,
1240 		.suspend_late = acpi_lpss_suspend_late,
1241 		.suspend_noirq = acpi_lpss_suspend_noirq,
1242 		.resume_noirq = acpi_lpss_resume_noirq,
1243 		.resume_early = acpi_lpss_resume_early,
1244 		.freeze = acpi_subsys_freeze,
1245 		.poweroff = acpi_subsys_poweroff,
1246 		.poweroff_late = acpi_lpss_poweroff_late,
1247 		.poweroff_noirq = acpi_lpss_poweroff_noirq,
1248 		.restore_noirq = acpi_lpss_restore_noirq,
1249 		.restore_early = acpi_lpss_restore_early,
1250 #endif
1251 		.runtime_suspend = acpi_lpss_runtime_suspend,
1252 		.runtime_resume = acpi_lpss_runtime_resume,
1253 #endif
1254 	},
1255 };
1256 
1257 static int acpi_lpss_platform_notify(struct notifier_block *nb,
1258 				     unsigned long action, void *data)
1259 {
1260 	struct platform_device *pdev = to_platform_device(data);
1261 	struct lpss_private_data *pdata;
1262 	struct acpi_device *adev;
1263 	const struct acpi_device_id *id;
1264 
1265 	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
1266 	if (!id || !id->driver_data)
1267 		return 0;
1268 
1269 	adev = ACPI_COMPANION(&pdev->dev);
1270 	if (!adev)
1271 		return 0;
1272 
1273 	pdata = acpi_driver_data(adev);
1274 	if (!pdata)
1275 		return 0;
1276 
1277 	if (pdata->mmio_base &&
1278 	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
1279 		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
1280 		return 0;
1281 	}
1282 
1283 	switch (action) {
1284 	case BUS_NOTIFY_BIND_DRIVER:
1285 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1286 		break;
1287 	case BUS_NOTIFY_DRIVER_NOT_BOUND:
1288 	case BUS_NOTIFY_UNBOUND_DRIVER:
1289 		dev_pm_domain_set(&pdev->dev, NULL);
1290 		break;
1291 	case BUS_NOTIFY_ADD_DEVICE:
1292 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1293 		if (pdata->dev_desc->flags & LPSS_LTR)
1294 			return sysfs_create_group(&pdev->dev.kobj,
1295 						  &lpss_attr_group);
1296 		break;
1297 	case BUS_NOTIFY_DEL_DEVICE:
1298 		if (pdata->dev_desc->flags & LPSS_LTR)
1299 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
1300 		dev_pm_domain_set(&pdev->dev, NULL);
1301 		break;
1302 	default:
1303 		break;
1304 	}
1305 
1306 	return 0;
1307 }
1308 
1309 static struct notifier_block acpi_lpss_nb = {
1310 	.notifier_call = acpi_lpss_platform_notify,
1311 };
1312 
1313 static void acpi_lpss_bind(struct device *dev)
1314 {
1315 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1316 
1317 	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
1318 		return;
1319 
1320 	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
1321 		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
1322 	else
1323 		dev_err(dev, "MMIO size insufficient to access LTR\n");
1324 }
1325 
1326 static void acpi_lpss_unbind(struct device *dev)
1327 {
1328 	dev->power.set_latency_tolerance = NULL;
1329 }
1330 
1331 static struct acpi_scan_handler lpss_handler = {
1332 	.ids = acpi_lpss_device_ids,
1333 	.attach = acpi_lpss_create_device,
1334 	.bind = acpi_lpss_bind,
1335 	.unbind = acpi_lpss_unbind,
1336 };
1337 
1338 void __init acpi_lpss_init(void)
1339 {
1340 	const struct x86_cpu_id *id;
1341 	int ret;
1342 
1343 	ret = lpss_atom_clk_init();
1344 	if (ret)
1345 		return;
1346 
1347 	id = x86_match_cpu(lpss_cpu_ids);
1348 	if (id)
1349 		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
1350 
1351 	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
1352 	acpi_scan_add_handler(&lpss_handler);
1353 }
1354 
1355 #else
1356 
1357 static struct acpi_scan_handler lpss_handler = {
1358 	.ids = acpi_lpss_device_ids,
1359 };
1360 
1361 void __init acpi_lpss_init(void)
1362 {
1363 	acpi_scan_add_handler(&lpss_handler);
1364 }
1365 
1366 #endif /* CONFIG_X86_INTEL_LPSS */
1367