xref: /openbmc/linux/drivers/acpi/acpi_lpss.c (revision 3e30a927)
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 #define ICPU(model)	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }
310 
311 static const struct x86_cpu_id lpss_cpu_ids[] = {
312 	ICPU(INTEL_FAM6_ATOM_SILVERMONT),	/* Valleyview, Bay Trail */
313 	ICPU(INTEL_FAM6_ATOM_AIRMONT),	/* Braswell, Cherry Trail */
314 	{}
315 };
316 
317 #else
318 
319 #define LPSS_ADDR(desc) (0UL)
320 
321 #endif /* CONFIG_X86_INTEL_LPSS */
322 
323 static const struct acpi_device_id acpi_lpss_device_ids[] = {
324 	/* Generic LPSS devices */
325 	{ "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
326 
327 	/* Lynxpoint LPSS devices */
328 	{ "INT33C0", LPSS_ADDR(lpt_dev_desc) },
329 	{ "INT33C1", LPSS_ADDR(lpt_dev_desc) },
330 	{ "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
331 	{ "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
332 	{ "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
333 	{ "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
334 	{ "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
335 	{ "INT33C7", },
336 
337 	/* BayTrail LPSS devices */
338 	{ "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
339 	{ "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
340 	{ "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
341 	{ "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
342 	{ "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
343 	{ "INT33B2", },
344 	{ "INT33FC", },
345 
346 	/* Braswell LPSS devices */
347 	{ "80862286", LPSS_ADDR(lpss_dma_desc) },
348 	{ "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
349 	{ "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
350 	{ "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
351 	{ "808622C0", LPSS_ADDR(lpss_dma_desc) },
352 	{ "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
353 
354 	/* Broadwell LPSS devices */
355 	{ "INT3430", LPSS_ADDR(lpt_dev_desc) },
356 	{ "INT3431", LPSS_ADDR(lpt_dev_desc) },
357 	{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
358 	{ "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
359 	{ "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
360 	{ "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
361 	{ "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
362 	{ "INT3437", },
363 
364 	/* Wildcat Point LPSS devices */
365 	{ "INT3438", LPSS_ADDR(lpt_dev_desc) },
366 
367 	{ }
368 };
369 
370 #ifdef CONFIG_X86_INTEL_LPSS
371 
372 static int is_memory(struct acpi_resource *res, void *not_used)
373 {
374 	struct resource r;
375 	return !acpi_dev_resource_memory(res, &r);
376 }
377 
378 /* LPSS main clock device. */
379 static struct platform_device *lpss_clk_dev;
380 
381 static inline void lpt_register_clock_device(void)
382 {
383 	lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
384 }
385 
386 static int register_device_clock(struct acpi_device *adev,
387 				 struct lpss_private_data *pdata)
388 {
389 	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
390 	const char *devname = dev_name(&adev->dev);
391 	struct clk *clk;
392 	struct lpss_clk_data *clk_data;
393 	const char *parent, *clk_name;
394 	void __iomem *prv_base;
395 
396 	if (!lpss_clk_dev)
397 		lpt_register_clock_device();
398 
399 	clk_data = platform_get_drvdata(lpss_clk_dev);
400 	if (!clk_data)
401 		return -ENODEV;
402 	clk = clk_data->clk;
403 
404 	if (!pdata->mmio_base
405 	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
406 		return -ENODATA;
407 
408 	parent = clk_data->name;
409 	prv_base = pdata->mmio_base + dev_desc->prv_offset;
410 
411 	if (pdata->fixed_clk_rate) {
412 		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
413 					      pdata->fixed_clk_rate);
414 		goto out;
415 	}
416 
417 	if (dev_desc->flags & LPSS_CLK_GATE) {
418 		clk = clk_register_gate(NULL, devname, parent, 0,
419 					prv_base, 0, 0, NULL);
420 		parent = devname;
421 	}
422 
423 	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
424 		/* Prevent division by zero */
425 		if (!readl(prv_base))
426 			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
427 
428 		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
429 		if (!clk_name)
430 			return -ENOMEM;
431 		clk = clk_register_fractional_divider(NULL, clk_name, parent,
432 						      0, prv_base,
433 						      1, 15, 16, 15, 0, NULL);
434 		parent = clk_name;
435 
436 		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
437 		if (!clk_name) {
438 			kfree(parent);
439 			return -ENOMEM;
440 		}
441 		clk = clk_register_gate(NULL, clk_name, parent,
442 					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
443 					prv_base, 31, 0, NULL);
444 		kfree(parent);
445 		kfree(clk_name);
446 	}
447 out:
448 	if (IS_ERR(clk))
449 		return PTR_ERR(clk);
450 
451 	pdata->clk = clk;
452 	clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
453 	return 0;
454 }
455 
456 struct lpss_device_links {
457 	const char *supplier_hid;
458 	const char *supplier_uid;
459 	const char *consumer_hid;
460 	const char *consumer_uid;
461 	u32 flags;
462 	const struct dmi_system_id *dep_missing_ids;
463 };
464 
465 /* Please keep this list sorted alphabetically by vendor and model */
466 static const struct dmi_system_id i2c1_dep_missing_dmi_ids[] = {
467 	{
468 		.matches = {
469 			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
470 			DMI_MATCH(DMI_PRODUCT_NAME, "T200TA"),
471 		},
472 	},
473 	{}
474 };
475 
476 /*
477  * The _DEP method is used to identify dependencies but instead of creating
478  * device links for every handle in _DEP, only links in the following list are
479  * created. That is necessary because, in the general case, _DEP can refer to
480  * devices that might not have drivers, or that are on different buses, or where
481  * the supplier is not enumerated until after the consumer is probed.
482  */
483 static const struct lpss_device_links lpss_device_links[] = {
484 	/* CHT External sdcard slot controller depends on PMIC I2C ctrl */
485 	{"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME},
486 	/* CHT iGPU depends on PMIC I2C controller */
487 	{"808622C1", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
488 	/* BYT iGPU depends on the Embedded Controller I2C controller (UID 1) */
489 	{"80860F41", "1", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME,
490 	 i2c1_dep_missing_dmi_ids},
491 	/* BYT CR iGPU depends on PMIC I2C controller (UID 5 on CR) */
492 	{"80860F41", "5", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
493 	/* BYT iGPU depends on PMIC I2C controller (UID 7 on non CR) */
494 	{"80860F41", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
495 };
496 
497 static bool acpi_lpss_is_supplier(struct acpi_device *adev,
498 				  const struct lpss_device_links *link)
499 {
500 	return acpi_dev_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 acpi_dev_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, const void *data)
515 {
516 	struct acpi_device *adev = ACPI_COMPANION(dev);
517 	const struct hid_uid *id = data;
518 
519 	if (!adev)
520 		return 0;
521 
522 	return acpi_dev_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 ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
575 	    || acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1)))
576 		device_link_add(dev2, dev1, link->flags);
577 
578 	put_device(dev2);
579 }
580 
581 static void acpi_lpss_link_supplier(struct device *dev1,
582 				    const struct lpss_device_links *link)
583 {
584 	struct device *dev2;
585 
586 	dev2 = acpi_lpss_find_device(link->supplier_hid, link->supplier_uid);
587 	if (!dev2)
588 		return;
589 
590 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
591 	    || acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2)))
592 		device_link_add(dev1, dev2, link->flags);
593 
594 	put_device(dev2);
595 }
596 
597 static void acpi_lpss_create_device_links(struct acpi_device *adev,
598 					  struct platform_device *pdev)
599 {
600 	int i;
601 
602 	for (i = 0; i < ARRAY_SIZE(lpss_device_links); i++) {
603 		const struct lpss_device_links *link = &lpss_device_links[i];
604 
605 		if (acpi_lpss_is_supplier(adev, link))
606 			acpi_lpss_link_consumer(&pdev->dev, link);
607 
608 		if (acpi_lpss_is_consumer(adev, link))
609 			acpi_lpss_link_supplier(&pdev->dev, link);
610 	}
611 }
612 
613 static int acpi_lpss_create_device(struct acpi_device *adev,
614 				   const struct acpi_device_id *id)
615 {
616 	const struct lpss_device_desc *dev_desc;
617 	struct lpss_private_data *pdata;
618 	struct resource_entry *rentry;
619 	struct list_head resource_list;
620 	struct platform_device *pdev;
621 	int ret;
622 
623 	dev_desc = (const struct lpss_device_desc *)id->driver_data;
624 	if (!dev_desc) {
625 		pdev = acpi_create_platform_device(adev, NULL);
626 		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
627 	}
628 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
629 	if (!pdata)
630 		return -ENOMEM;
631 
632 	INIT_LIST_HEAD(&resource_list);
633 	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
634 	if (ret < 0)
635 		goto err_out;
636 
637 	list_for_each_entry(rentry, &resource_list, node)
638 		if (resource_type(rentry->res) == IORESOURCE_MEM) {
639 			if (dev_desc->prv_size_override)
640 				pdata->mmio_size = dev_desc->prv_size_override;
641 			else
642 				pdata->mmio_size = resource_size(rentry->res);
643 			pdata->mmio_base = ioremap(rentry->res->start,
644 						   pdata->mmio_size);
645 			break;
646 		}
647 
648 	acpi_dev_free_resource_list(&resource_list);
649 
650 	if (!pdata->mmio_base) {
651 		/* Avoid acpi_bus_attach() instantiating a pdev for this dev. */
652 		adev->pnp.type.platform_id = 0;
653 		/* Skip the device, but continue the namespace scan. */
654 		ret = 0;
655 		goto err_out;
656 	}
657 
658 	pdata->adev = adev;
659 	pdata->dev_desc = dev_desc;
660 
661 	if (dev_desc->setup)
662 		dev_desc->setup(pdata);
663 
664 	if (dev_desc->flags & LPSS_CLK) {
665 		ret = register_device_clock(adev, pdata);
666 		if (ret) {
667 			/* Skip the device, but continue the namespace scan. */
668 			ret = 0;
669 			goto err_out;
670 		}
671 	}
672 
673 	/*
674 	 * This works around a known issue in ACPI tables where LPSS devices
675 	 * have _PS0 and _PS3 without _PSC (and no power resources), so
676 	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
677 	 */
678 	acpi_device_fix_up_power(adev);
679 
680 	adev->driver_data = pdata;
681 	pdev = acpi_create_platform_device(adev, dev_desc->properties);
682 	if (!IS_ERR_OR_NULL(pdev)) {
683 		acpi_lpss_create_device_links(adev, pdev);
684 		return 1;
685 	}
686 
687 	ret = PTR_ERR(pdev);
688 	adev->driver_data = NULL;
689 
690  err_out:
691 	kfree(pdata);
692 	return ret;
693 }
694 
695 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
696 {
697 	return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
698 }
699 
700 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
701 			     unsigned int reg)
702 {
703 	writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
704 }
705 
706 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
707 {
708 	struct acpi_device *adev;
709 	struct lpss_private_data *pdata;
710 	unsigned long flags;
711 	int ret;
712 
713 	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
714 	if (WARN_ON(ret))
715 		return ret;
716 
717 	spin_lock_irqsave(&dev->power.lock, flags);
718 	if (pm_runtime_suspended(dev)) {
719 		ret = -EAGAIN;
720 		goto out;
721 	}
722 	pdata = acpi_driver_data(adev);
723 	if (WARN_ON(!pdata || !pdata->mmio_base)) {
724 		ret = -ENODEV;
725 		goto out;
726 	}
727 	*val = __lpss_reg_read(pdata, reg);
728 
729  out:
730 	spin_unlock_irqrestore(&dev->power.lock, flags);
731 	return ret;
732 }
733 
734 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
735 			     char *buf)
736 {
737 	u32 ltr_value = 0;
738 	unsigned int reg;
739 	int ret;
740 
741 	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
742 	ret = lpss_reg_read(dev, reg, &ltr_value);
743 	if (ret)
744 		return ret;
745 
746 	return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
747 }
748 
749 static ssize_t lpss_ltr_mode_show(struct device *dev,
750 				  struct device_attribute *attr, char *buf)
751 {
752 	u32 ltr_mode = 0;
753 	char *outstr;
754 	int ret;
755 
756 	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
757 	if (ret)
758 		return ret;
759 
760 	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
761 	return sprintf(buf, "%s\n", outstr);
762 }
763 
764 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
765 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
766 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
767 
768 static struct attribute *lpss_attrs[] = {
769 	&dev_attr_auto_ltr.attr,
770 	&dev_attr_sw_ltr.attr,
771 	&dev_attr_ltr_mode.attr,
772 	NULL,
773 };
774 
775 static const struct attribute_group lpss_attr_group = {
776 	.attrs = lpss_attrs,
777 	.name = "lpss_ltr",
778 };
779 
780 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
781 {
782 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
783 	u32 ltr_mode, ltr_val;
784 
785 	ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
786 	if (val < 0) {
787 		if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
788 			ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
789 			__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
790 		}
791 		return;
792 	}
793 	ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
794 	if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
795 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
796 		val = LPSS_LTR_MAX_VAL;
797 	} else if (val > LPSS_LTR_MAX_VAL) {
798 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
799 		val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
800 	} else {
801 		ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
802 	}
803 	ltr_val |= val;
804 	__lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
805 	if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
806 		ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
807 		__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
808 	}
809 }
810 
811 #ifdef CONFIG_PM
812 /**
813  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
814  * @dev: LPSS device
815  * @pdata: pointer to the private data of the LPSS device
816  *
817  * Most LPSS devices have private registers which may loose their context when
818  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
819  * prv_reg_ctx array.
820  */
821 static void acpi_lpss_save_ctx(struct device *dev,
822 			       struct lpss_private_data *pdata)
823 {
824 	unsigned int i;
825 
826 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
827 		unsigned long offset = i * sizeof(u32);
828 
829 		pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
830 		dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
831 			pdata->prv_reg_ctx[i], offset);
832 	}
833 }
834 
835 /**
836  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
837  * @dev: LPSS device
838  * @pdata: pointer to the private data of the LPSS device
839  *
840  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
841  */
842 static void acpi_lpss_restore_ctx(struct device *dev,
843 				  struct lpss_private_data *pdata)
844 {
845 	unsigned int i;
846 
847 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
848 		unsigned long offset = i * sizeof(u32);
849 
850 		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
851 		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
852 			pdata->prv_reg_ctx[i], offset);
853 	}
854 }
855 
856 static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
857 {
858 	/*
859 	 * The following delay is needed or the subsequent write operations may
860 	 * fail. The LPSS devices are actually PCI devices and the PCI spec
861 	 * expects 10ms delay before the device can be accessed after D3 to D0
862 	 * transition. However some platforms like BSW does not need this delay.
863 	 */
864 	unsigned int delay = 10;	/* default 10ms delay */
865 
866 	if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
867 		delay = 0;
868 
869 	msleep(delay);
870 }
871 
872 static int acpi_lpss_activate(struct device *dev)
873 {
874 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
875 	int ret;
876 
877 	ret = acpi_dev_resume(dev);
878 	if (ret)
879 		return ret;
880 
881 	acpi_lpss_d3_to_d0_delay(pdata);
882 
883 	/*
884 	 * This is called only on ->probe() stage where a device is either in
885 	 * known state defined by BIOS or most likely powered off. Due to this
886 	 * we have to deassert reset line to be sure that ->probe() will
887 	 * recognize the device.
888 	 */
889 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
890 		lpss_deassert_reset(pdata);
891 
892 	return 0;
893 }
894 
895 static void acpi_lpss_dismiss(struct device *dev)
896 {
897 	acpi_dev_suspend(dev, false);
898 }
899 
900 /* IOSF SB for LPSS island */
901 #define LPSS_IOSF_UNIT_LPIOEP		0xA0
902 #define LPSS_IOSF_UNIT_LPIO1		0xAB
903 #define LPSS_IOSF_UNIT_LPIO2		0xAC
904 
905 #define LPSS_IOSF_PMCSR			0x84
906 #define LPSS_PMCSR_D0			0
907 #define LPSS_PMCSR_D3hot		3
908 #define LPSS_PMCSR_Dx_MASK		GENMASK(1, 0)
909 
910 #define LPSS_IOSF_GPIODEF0		0x154
911 #define LPSS_GPIODEF0_DMA1_D3		BIT(2)
912 #define LPSS_GPIODEF0_DMA2_D3		BIT(3)
913 #define LPSS_GPIODEF0_DMA_D3_MASK	GENMASK(3, 2)
914 #define LPSS_GPIODEF0_DMA_LLP		BIT(13)
915 
916 static DEFINE_MUTEX(lpss_iosf_mutex);
917 static bool lpss_iosf_d3_entered = true;
918 
919 static void lpss_iosf_enter_d3_state(void)
920 {
921 	u32 value1 = 0;
922 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
923 	u32 value2 = LPSS_PMCSR_D3hot;
924 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
925 	/*
926 	 * PMC provides an information about actual status of the LPSS devices.
927 	 * Here we read the values related to LPSS power island, i.e. LPSS
928 	 * devices, excluding both LPSS DMA controllers, along with SCC domain.
929 	 */
930 	u32 func_dis, d3_sts_0, pmc_status;
931 	int ret;
932 
933 	ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
934 	if (ret)
935 		return;
936 
937 	mutex_lock(&lpss_iosf_mutex);
938 
939 	ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
940 	if (ret)
941 		goto exit;
942 
943 	/*
944 	 * Get the status of entire LPSS power island per device basis.
945 	 * Shutdown both LPSS DMA controllers if and only if all other devices
946 	 * are already in D3hot.
947 	 */
948 	pmc_status = (~(d3_sts_0 | func_dis)) & pmc_atom_d3_mask;
949 	if (pmc_status)
950 		goto exit;
951 
952 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
953 			LPSS_IOSF_PMCSR, value2, mask2);
954 
955 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
956 			LPSS_IOSF_PMCSR, value2, mask2);
957 
958 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
959 			LPSS_IOSF_GPIODEF0, value1, mask1);
960 
961 	lpss_iosf_d3_entered = true;
962 
963 exit:
964 	mutex_unlock(&lpss_iosf_mutex);
965 }
966 
967 static void lpss_iosf_exit_d3_state(void)
968 {
969 	u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3 |
970 		     LPSS_GPIODEF0_DMA_LLP;
971 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
972 	u32 value2 = LPSS_PMCSR_D0;
973 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
974 
975 	mutex_lock(&lpss_iosf_mutex);
976 
977 	if (!lpss_iosf_d3_entered)
978 		goto exit;
979 
980 	lpss_iosf_d3_entered = false;
981 
982 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
983 			LPSS_IOSF_GPIODEF0, value1, mask1);
984 
985 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
986 			LPSS_IOSF_PMCSR, value2, mask2);
987 
988 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
989 			LPSS_IOSF_PMCSR, value2, mask2);
990 
991 exit:
992 	mutex_unlock(&lpss_iosf_mutex);
993 }
994 
995 static int acpi_lpss_suspend(struct device *dev, bool wakeup)
996 {
997 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
998 	int ret;
999 
1000 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
1001 		acpi_lpss_save_ctx(dev, pdata);
1002 
1003 	ret = acpi_dev_suspend(dev, wakeup);
1004 
1005 	/*
1006 	 * This call must be last in the sequence, otherwise PMC will return
1007 	 * wrong status for devices being about to be powered off. See
1008 	 * lpss_iosf_enter_d3_state() for further information.
1009 	 */
1010 	if (acpi_target_system_state() == ACPI_STATE_S0 &&
1011 	    lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1012 		lpss_iosf_enter_d3_state();
1013 
1014 	return ret;
1015 }
1016 
1017 static int acpi_lpss_resume(struct device *dev)
1018 {
1019 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1020 	int ret;
1021 
1022 	/*
1023 	 * This call is kept first to be in symmetry with
1024 	 * acpi_lpss_runtime_suspend() one.
1025 	 */
1026 	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1027 		lpss_iosf_exit_d3_state();
1028 
1029 	ret = acpi_dev_resume(dev);
1030 	if (ret)
1031 		return ret;
1032 
1033 	acpi_lpss_d3_to_d0_delay(pdata);
1034 
1035 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
1036 		acpi_lpss_restore_ctx(dev, pdata);
1037 
1038 	return 0;
1039 }
1040 
1041 #ifdef CONFIG_PM_SLEEP
1042 static int acpi_lpss_do_suspend_late(struct device *dev)
1043 {
1044 	int ret;
1045 
1046 	if (dev_pm_smart_suspend_and_suspended(dev))
1047 		return 0;
1048 
1049 	ret = pm_generic_suspend_late(dev);
1050 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1051 }
1052 
1053 static int acpi_lpss_suspend_late(struct device *dev)
1054 {
1055 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1056 
1057 	if (pdata->dev_desc->resume_from_noirq)
1058 		return 0;
1059 
1060 	return acpi_lpss_do_suspend_late(dev);
1061 }
1062 
1063 static int acpi_lpss_suspend_noirq(struct device *dev)
1064 {
1065 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1066 	int ret;
1067 
1068 	if (pdata->dev_desc->resume_from_noirq) {
1069 		/*
1070 		 * The driver's ->suspend_late callback will be invoked by
1071 		 * acpi_lpss_do_suspend_late(), with the assumption that the
1072 		 * driver really wanted to run that code in ->suspend_noirq, but
1073 		 * it could not run after acpi_dev_suspend() and the driver
1074 		 * expected the latter to be called in the "late" phase.
1075 		 */
1076 		ret = acpi_lpss_do_suspend_late(dev);
1077 		if (ret)
1078 			return ret;
1079 	}
1080 
1081 	return acpi_subsys_suspend_noirq(dev);
1082 }
1083 
1084 static int acpi_lpss_do_resume_early(struct device *dev)
1085 {
1086 	int ret = acpi_lpss_resume(dev);
1087 
1088 	return ret ? ret : pm_generic_resume_early(dev);
1089 }
1090 
1091 static int acpi_lpss_resume_early(struct device *dev)
1092 {
1093 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1094 
1095 	if (pdata->dev_desc->resume_from_noirq)
1096 		return 0;
1097 
1098 	return acpi_lpss_do_resume_early(dev);
1099 }
1100 
1101 static int acpi_lpss_resume_noirq(struct device *dev)
1102 {
1103 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1104 	int ret;
1105 
1106 	/* Follow acpi_subsys_resume_noirq(). */
1107 	if (dev_pm_may_skip_resume(dev))
1108 		return 0;
1109 
1110 	if (dev_pm_smart_suspend_and_suspended(dev))
1111 		pm_runtime_set_active(dev);
1112 
1113 	ret = pm_generic_resume_noirq(dev);
1114 	if (ret)
1115 		return ret;
1116 
1117 	if (!pdata->dev_desc->resume_from_noirq)
1118 		return 0;
1119 
1120 	/*
1121 	 * The driver's ->resume_early callback will be invoked by
1122 	 * acpi_lpss_do_resume_early(), with the assumption that the driver
1123 	 * really wanted to run that code in ->resume_noirq, but it could not
1124 	 * run before acpi_dev_resume() and the driver expected the latter to be
1125 	 * called in the "early" phase.
1126 	 */
1127 	return acpi_lpss_do_resume_early(dev);
1128 }
1129 
1130 static int acpi_lpss_do_restore_early(struct device *dev)
1131 {
1132 	int ret = acpi_lpss_resume(dev);
1133 
1134 	return ret ? ret : pm_generic_restore_early(dev);
1135 }
1136 
1137 static int acpi_lpss_restore_early(struct device *dev)
1138 {
1139 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1140 
1141 	if (pdata->dev_desc->resume_from_noirq)
1142 		return 0;
1143 
1144 	return acpi_lpss_do_restore_early(dev);
1145 }
1146 
1147 static int acpi_lpss_restore_noirq(struct device *dev)
1148 {
1149 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1150 	int ret;
1151 
1152 	ret = pm_generic_restore_noirq(dev);
1153 	if (ret)
1154 		return ret;
1155 
1156 	if (!pdata->dev_desc->resume_from_noirq)
1157 		return 0;
1158 
1159 	/* This is analogous to what happens in acpi_lpss_resume_noirq(). */
1160 	return acpi_lpss_do_restore_early(dev);
1161 }
1162 
1163 static int acpi_lpss_do_poweroff_late(struct device *dev)
1164 {
1165 	int ret = pm_generic_poweroff_late(dev);
1166 
1167 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1168 }
1169 
1170 static int acpi_lpss_poweroff_late(struct device *dev)
1171 {
1172 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1173 
1174 	if (dev_pm_smart_suspend_and_suspended(dev))
1175 		return 0;
1176 
1177 	if (pdata->dev_desc->resume_from_noirq)
1178 		return 0;
1179 
1180 	return acpi_lpss_do_poweroff_late(dev);
1181 }
1182 
1183 static int acpi_lpss_poweroff_noirq(struct device *dev)
1184 {
1185 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1186 
1187 	if (dev_pm_smart_suspend_and_suspended(dev))
1188 		return 0;
1189 
1190 	if (pdata->dev_desc->resume_from_noirq) {
1191 		/* This is analogous to the acpi_lpss_suspend_noirq() case. */
1192 		int ret = acpi_lpss_do_poweroff_late(dev);
1193 		if (ret)
1194 			return ret;
1195 	}
1196 
1197 	return pm_generic_poweroff_noirq(dev);
1198 }
1199 #endif /* CONFIG_PM_SLEEP */
1200 
1201 static int acpi_lpss_runtime_suspend(struct device *dev)
1202 {
1203 	int ret = pm_generic_runtime_suspend(dev);
1204 
1205 	return ret ? ret : acpi_lpss_suspend(dev, true);
1206 }
1207 
1208 static int acpi_lpss_runtime_resume(struct device *dev)
1209 {
1210 	int ret = acpi_lpss_resume(dev);
1211 
1212 	return ret ? ret : pm_generic_runtime_resume(dev);
1213 }
1214 #endif /* CONFIG_PM */
1215 
1216 static struct dev_pm_domain acpi_lpss_pm_domain = {
1217 #ifdef CONFIG_PM
1218 	.activate = acpi_lpss_activate,
1219 	.dismiss = acpi_lpss_dismiss,
1220 #endif
1221 	.ops = {
1222 #ifdef CONFIG_PM
1223 #ifdef CONFIG_PM_SLEEP
1224 		.prepare = acpi_subsys_prepare,
1225 		.complete = acpi_subsys_complete,
1226 		.suspend = acpi_subsys_suspend,
1227 		.suspend_late = acpi_lpss_suspend_late,
1228 		.suspend_noirq = acpi_lpss_suspend_noirq,
1229 		.resume_noirq = acpi_lpss_resume_noirq,
1230 		.resume_early = acpi_lpss_resume_early,
1231 		.freeze = acpi_subsys_freeze,
1232 		.poweroff = acpi_subsys_poweroff,
1233 		.poweroff_late = acpi_lpss_poweroff_late,
1234 		.poweroff_noirq = acpi_lpss_poweroff_noirq,
1235 		.restore_noirq = acpi_lpss_restore_noirq,
1236 		.restore_early = acpi_lpss_restore_early,
1237 #endif
1238 		.runtime_suspend = acpi_lpss_runtime_suspend,
1239 		.runtime_resume = acpi_lpss_runtime_resume,
1240 #endif
1241 	},
1242 };
1243 
1244 static int acpi_lpss_platform_notify(struct notifier_block *nb,
1245 				     unsigned long action, void *data)
1246 {
1247 	struct platform_device *pdev = to_platform_device(data);
1248 	struct lpss_private_data *pdata;
1249 	struct acpi_device *adev;
1250 	const struct acpi_device_id *id;
1251 
1252 	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
1253 	if (!id || !id->driver_data)
1254 		return 0;
1255 
1256 	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
1257 		return 0;
1258 
1259 	pdata = acpi_driver_data(adev);
1260 	if (!pdata)
1261 		return 0;
1262 
1263 	if (pdata->mmio_base &&
1264 	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
1265 		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
1266 		return 0;
1267 	}
1268 
1269 	switch (action) {
1270 	case BUS_NOTIFY_BIND_DRIVER:
1271 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1272 		break;
1273 	case BUS_NOTIFY_DRIVER_NOT_BOUND:
1274 	case BUS_NOTIFY_UNBOUND_DRIVER:
1275 		dev_pm_domain_set(&pdev->dev, NULL);
1276 		break;
1277 	case BUS_NOTIFY_ADD_DEVICE:
1278 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1279 		if (pdata->dev_desc->flags & LPSS_LTR)
1280 			return sysfs_create_group(&pdev->dev.kobj,
1281 						  &lpss_attr_group);
1282 		break;
1283 	case BUS_NOTIFY_DEL_DEVICE:
1284 		if (pdata->dev_desc->flags & LPSS_LTR)
1285 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
1286 		dev_pm_domain_set(&pdev->dev, NULL);
1287 		break;
1288 	default:
1289 		break;
1290 	}
1291 
1292 	return 0;
1293 }
1294 
1295 static struct notifier_block acpi_lpss_nb = {
1296 	.notifier_call = acpi_lpss_platform_notify,
1297 };
1298 
1299 static void acpi_lpss_bind(struct device *dev)
1300 {
1301 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1302 
1303 	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
1304 		return;
1305 
1306 	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
1307 		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
1308 	else
1309 		dev_err(dev, "MMIO size insufficient to access LTR\n");
1310 }
1311 
1312 static void acpi_lpss_unbind(struct device *dev)
1313 {
1314 	dev->power.set_latency_tolerance = NULL;
1315 }
1316 
1317 static struct acpi_scan_handler lpss_handler = {
1318 	.ids = acpi_lpss_device_ids,
1319 	.attach = acpi_lpss_create_device,
1320 	.bind = acpi_lpss_bind,
1321 	.unbind = acpi_lpss_unbind,
1322 };
1323 
1324 void __init acpi_lpss_init(void)
1325 {
1326 	const struct x86_cpu_id *id;
1327 	int ret;
1328 
1329 	ret = lpt_clk_init();
1330 	if (ret)
1331 		return;
1332 
1333 	id = x86_match_cpu(lpss_cpu_ids);
1334 	if (id)
1335 		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
1336 
1337 	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
1338 	acpi_scan_add_handler(&lpss_handler);
1339 }
1340 
1341 #else
1342 
1343 static struct acpi_scan_handler lpss_handler = {
1344 	.ids = acpi_lpss_device_ids,
1345 };
1346 
1347 void __init acpi_lpss_init(void)
1348 {
1349 	acpi_scan_add_handler(&lpss_handler);
1350 }
1351 
1352 #endif /* CONFIG_X86_INTEL_LPSS */
1353