xref: /openbmc/linux/drivers/acpi/acpi_lpss.c (revision f7af616c)
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)
190 		uid = simple_strtol(uid_str, NULL, 10);
191 
192 	/* Detect I2C bus shared with PUNIT and ignore its d3 status */
193 	status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
194 	if (ACPI_SUCCESS(status) && shared_host && uid)
195 		pmc_atom_d3_mask &= ~(BIT_LPSS2_F1_I2C1 << (uid - 1));
196 
197 	lpss_deassert_reset(pdata);
198 
199 	if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
200 		pdata->fixed_clk_rate = 133000000;
201 
202 	writel(0, pdata->mmio_base + LPSS_I2C_ENABLE);
203 }
204 
205 /* BSW PWM used for backlight control by the i915 driver */
206 static struct pwm_lookup bsw_pwm_lookup[] = {
207 	PWM_LOOKUP_WITH_MODULE("80862288:00", 0, "0000:00:02.0",
208 			       "pwm_soc_backlight", 0, PWM_POLARITY_NORMAL,
209 			       "pwm-lpss-platform"),
210 };
211 
212 static void bsw_pwm_setup(struct lpss_private_data *pdata)
213 {
214 	struct acpi_device *adev = pdata->adev;
215 
216 	/* Only call pwm_add_table for the first PWM controller */
217 	if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
218 		return;
219 
220 	pwm_add_table(bsw_pwm_lookup, ARRAY_SIZE(bsw_pwm_lookup));
221 }
222 
223 static const struct lpss_device_desc lpt_dev_desc = {
224 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR
225 			| LPSS_SAVE_CTX,
226 	.prv_offset = 0x800,
227 };
228 
229 static const struct lpss_device_desc lpt_i2c_dev_desc = {
230 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR | LPSS_SAVE_CTX,
231 	.prv_offset = 0x800,
232 };
233 
234 static struct property_entry uart_properties[] = {
235 	PROPERTY_ENTRY_U32("reg-io-width", 4),
236 	PROPERTY_ENTRY_U32("reg-shift", 2),
237 	PROPERTY_ENTRY_BOOL("snps,uart-16550-compatible"),
238 	{ },
239 };
240 
241 static const struct lpss_device_desc lpt_uart_dev_desc = {
242 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR
243 			| LPSS_SAVE_CTX,
244 	.clk_con_id = "baudclk",
245 	.prv_offset = 0x800,
246 	.setup = lpss_uart_setup,
247 	.properties = uart_properties,
248 };
249 
250 static const struct lpss_device_desc lpt_sdio_dev_desc = {
251 	.flags = LPSS_LTR,
252 	.prv_offset = 0x1000,
253 	.prv_size_override = 0x1018,
254 };
255 
256 static const struct lpss_device_desc byt_pwm_dev_desc = {
257 	.flags = LPSS_SAVE_CTX,
258 	.prv_offset = 0x800,
259 	.setup = byt_pwm_setup,
260 };
261 
262 static const struct lpss_device_desc bsw_pwm_dev_desc = {
263 	.flags = LPSS_SAVE_CTX_ONCE | LPSS_NO_D3_DELAY,
264 	.prv_offset = 0x800,
265 	.setup = bsw_pwm_setup,
266 	.resume_from_noirq = true,
267 };
268 
269 static const struct lpss_device_desc byt_uart_dev_desc = {
270 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
271 	.clk_con_id = "baudclk",
272 	.prv_offset = 0x800,
273 	.setup = lpss_uart_setup,
274 	.properties = uart_properties,
275 };
276 
277 static const struct lpss_device_desc bsw_uart_dev_desc = {
278 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
279 			| LPSS_NO_D3_DELAY,
280 	.clk_con_id = "baudclk",
281 	.prv_offset = 0x800,
282 	.setup = lpss_uart_setup,
283 	.properties = uart_properties,
284 };
285 
286 static const struct lpss_device_desc byt_spi_dev_desc = {
287 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
288 	.prv_offset = 0x400,
289 };
290 
291 static const struct lpss_device_desc byt_sdio_dev_desc = {
292 	.flags = LPSS_CLK,
293 };
294 
295 static const struct lpss_device_desc byt_i2c_dev_desc = {
296 	.flags = LPSS_CLK | LPSS_SAVE_CTX,
297 	.prv_offset = 0x800,
298 	.setup = byt_i2c_setup,
299 	.resume_from_noirq = true,
300 };
301 
302 static const struct lpss_device_desc bsw_i2c_dev_desc = {
303 	.flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
304 	.prv_offset = 0x800,
305 	.setup = byt_i2c_setup,
306 	.resume_from_noirq = true,
307 };
308 
309 static const struct lpss_device_desc bsw_spi_dev_desc = {
310 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
311 			| LPSS_NO_D3_DELAY,
312 	.prv_offset = 0x400,
313 	.setup = lpss_deassert_reset,
314 };
315 
316 static const struct x86_cpu_id lpss_cpu_ids[] = {
317 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT,	NULL),
318 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT,	NULL),
319 	{}
320 };
321 
322 #else
323 
324 #define LPSS_ADDR(desc) (0UL)
325 
326 #endif /* CONFIG_X86_INTEL_LPSS */
327 
328 static const struct acpi_device_id acpi_lpss_device_ids[] = {
329 	/* Generic LPSS devices */
330 	{ "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
331 
332 	/* Lynxpoint LPSS devices */
333 	{ "INT33C0", LPSS_ADDR(lpt_dev_desc) },
334 	{ "INT33C1", LPSS_ADDR(lpt_dev_desc) },
335 	{ "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
336 	{ "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
337 	{ "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
338 	{ "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
339 	{ "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
340 	{ "INT33C7", },
341 
342 	/* BayTrail LPSS devices */
343 	{ "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
344 	{ "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
345 	{ "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
346 	{ "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
347 	{ "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
348 	{ "INT33B2", },
349 	{ "INT33FC", },
350 
351 	/* Braswell LPSS devices */
352 	{ "80862286", LPSS_ADDR(lpss_dma_desc) },
353 	{ "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
354 	{ "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
355 	{ "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
356 	{ "808622C0", LPSS_ADDR(lpss_dma_desc) },
357 	{ "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
358 
359 	/* Broadwell LPSS devices */
360 	{ "INT3430", LPSS_ADDR(lpt_dev_desc) },
361 	{ "INT3431", LPSS_ADDR(lpt_dev_desc) },
362 	{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
363 	{ "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
364 	{ "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
365 	{ "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
366 	{ "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
367 	{ "INT3437", },
368 
369 	/* Wildcat Point LPSS devices */
370 	{ "INT3438", LPSS_ADDR(lpt_dev_desc) },
371 
372 	{ }
373 };
374 
375 #ifdef CONFIG_X86_INTEL_LPSS
376 
377 static int is_memory(struct acpi_resource *res, void *not_used)
378 {
379 	struct resource r;
380 
381 	return !acpi_dev_resource_memory(res, &r);
382 }
383 
384 /* LPSS main clock device. */
385 static struct platform_device *lpss_clk_dev;
386 
387 static inline void lpt_register_clock_device(void)
388 {
389 	lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
390 }
391 
392 static int register_device_clock(struct acpi_device *adev,
393 				 struct lpss_private_data *pdata)
394 {
395 	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
396 	const char *devname = dev_name(&adev->dev);
397 	struct clk *clk;
398 	struct lpss_clk_data *clk_data;
399 	const char *parent, *clk_name;
400 	void __iomem *prv_base;
401 
402 	if (!lpss_clk_dev)
403 		lpt_register_clock_device();
404 
405 	clk_data = platform_get_drvdata(lpss_clk_dev);
406 	if (!clk_data)
407 		return -ENODEV;
408 	clk = clk_data->clk;
409 
410 	if (!pdata->mmio_base
411 	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
412 		return -ENODATA;
413 
414 	parent = clk_data->name;
415 	prv_base = pdata->mmio_base + dev_desc->prv_offset;
416 
417 	if (pdata->fixed_clk_rate) {
418 		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
419 					      pdata->fixed_clk_rate);
420 		goto out;
421 	}
422 
423 	if (dev_desc->flags & LPSS_CLK_GATE) {
424 		clk = clk_register_gate(NULL, devname, parent, 0,
425 					prv_base, 0, 0, NULL);
426 		parent = devname;
427 	}
428 
429 	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
430 		/* Prevent division by zero */
431 		if (!readl(prv_base))
432 			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
433 
434 		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
435 		if (!clk_name)
436 			return -ENOMEM;
437 		clk = clk_register_fractional_divider(NULL, clk_name, parent,
438 						      0, prv_base,
439 						      1, 15, 16, 15, 0, NULL);
440 		parent = clk_name;
441 
442 		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
443 		if (!clk_name) {
444 			kfree(parent);
445 			return -ENOMEM;
446 		}
447 		clk = clk_register_gate(NULL, clk_name, parent,
448 					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
449 					prv_base, 31, 0, NULL);
450 		kfree(parent);
451 		kfree(clk_name);
452 	}
453 out:
454 	if (IS_ERR(clk))
455 		return PTR_ERR(clk);
456 
457 	pdata->clk = clk;
458 	clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
459 	return 0;
460 }
461 
462 struct lpss_device_links {
463 	const char *supplier_hid;
464 	const char *supplier_uid;
465 	const char *consumer_hid;
466 	const char *consumer_uid;
467 	u32 flags;
468 	const struct dmi_system_id *dep_missing_ids;
469 };
470 
471 /* Please keep this list sorted alphabetically by vendor and model */
472 static const struct dmi_system_id i2c1_dep_missing_dmi_ids[] = {
473 	{
474 		.matches = {
475 			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
476 			DMI_MATCH(DMI_PRODUCT_NAME, "T200TA"),
477 		},
478 	},
479 	{}
480 };
481 
482 /*
483  * The _DEP method is used to identify dependencies but instead of creating
484  * device links for every handle in _DEP, only links in the following list are
485  * created. That is necessary because, in the general case, _DEP can refer to
486  * devices that might not have drivers, or that are on different buses, or where
487  * the supplier is not enumerated until after the consumer is probed.
488  */
489 static const struct lpss_device_links lpss_device_links[] = {
490 	/* CHT External sdcard slot controller depends on PMIC I2C ctrl */
491 	{"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME},
492 	/* CHT iGPU depends on PMIC I2C controller */
493 	{"808622C1", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
494 	/* BYT iGPU depends on the Embedded Controller I2C controller (UID 1) */
495 	{"80860F41", "1", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME,
496 	 i2c1_dep_missing_dmi_ids},
497 	/* BYT CR iGPU depends on PMIC I2C controller (UID 5 on CR) */
498 	{"80860F41", "5", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
499 	/* BYT iGPU depends on PMIC I2C controller (UID 7 on non CR) */
500 	{"80860F41", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
501 };
502 
503 static bool acpi_lpss_is_supplier(struct acpi_device *adev,
504 				  const struct lpss_device_links *link)
505 {
506 	return acpi_dev_hid_uid_match(adev, link->supplier_hid, link->supplier_uid);
507 }
508 
509 static bool acpi_lpss_is_consumer(struct acpi_device *adev,
510 				  const struct lpss_device_links *link)
511 {
512 	return acpi_dev_hid_uid_match(adev, link->consumer_hid, link->consumer_uid);
513 }
514 
515 struct hid_uid {
516 	const char *hid;
517 	const char *uid;
518 };
519 
520 static int match_hid_uid(struct device *dev, const void *data)
521 {
522 	struct acpi_device *adev = ACPI_COMPANION(dev);
523 	const struct hid_uid *id = data;
524 
525 	if (!adev)
526 		return 0;
527 
528 	return acpi_dev_hid_uid_match(adev, id->hid, id->uid);
529 }
530 
531 static struct device *acpi_lpss_find_device(const char *hid, const char *uid)
532 {
533 	struct device *dev;
534 
535 	struct hid_uid data = {
536 		.hid = hid,
537 		.uid = uid,
538 	};
539 
540 	dev = bus_find_device(&platform_bus_type, NULL, &data, match_hid_uid);
541 	if (dev)
542 		return dev;
543 
544 	return bus_find_device(&pci_bus_type, NULL, &data, match_hid_uid);
545 }
546 
547 static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle)
548 {
549 	struct acpi_handle_list dep_devices;
550 	acpi_status status;
551 	int i;
552 
553 	if (!acpi_has_method(adev->handle, "_DEP"))
554 		return false;
555 
556 	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
557 					 &dep_devices);
558 	if (ACPI_FAILURE(status)) {
559 		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
560 		return false;
561 	}
562 
563 	for (i = 0; i < dep_devices.count; i++) {
564 		if (dep_devices.handles[i] == handle)
565 			return true;
566 	}
567 
568 	return false;
569 }
570 
571 static void acpi_lpss_link_consumer(struct device *dev1,
572 				    const struct lpss_device_links *link)
573 {
574 	struct device *dev2;
575 
576 	dev2 = acpi_lpss_find_device(link->consumer_hid, link->consumer_uid);
577 	if (!dev2)
578 		return;
579 
580 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
581 	    || acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1)))
582 		device_link_add(dev2, dev1, link->flags);
583 
584 	put_device(dev2);
585 }
586 
587 static void acpi_lpss_link_supplier(struct device *dev1,
588 				    const struct lpss_device_links *link)
589 {
590 	struct device *dev2;
591 
592 	dev2 = acpi_lpss_find_device(link->supplier_hid, link->supplier_uid);
593 	if (!dev2)
594 		return;
595 
596 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
597 	    || acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2)))
598 		device_link_add(dev1, dev2, link->flags);
599 
600 	put_device(dev2);
601 }
602 
603 static void acpi_lpss_create_device_links(struct acpi_device *adev,
604 					  struct platform_device *pdev)
605 {
606 	int i;
607 
608 	for (i = 0; i < ARRAY_SIZE(lpss_device_links); i++) {
609 		const struct lpss_device_links *link = &lpss_device_links[i];
610 
611 		if (acpi_lpss_is_supplier(adev, link))
612 			acpi_lpss_link_consumer(&pdev->dev, link);
613 
614 		if (acpi_lpss_is_consumer(adev, link))
615 			acpi_lpss_link_supplier(&pdev->dev, link);
616 	}
617 }
618 
619 static int acpi_lpss_create_device(struct acpi_device *adev,
620 				   const struct acpi_device_id *id)
621 {
622 	const struct lpss_device_desc *dev_desc;
623 	struct lpss_private_data *pdata;
624 	struct resource_entry *rentry;
625 	struct list_head resource_list;
626 	struct platform_device *pdev;
627 	int ret;
628 
629 	dev_desc = (const struct lpss_device_desc *)id->driver_data;
630 	if (!dev_desc) {
631 		pdev = acpi_create_platform_device(adev, NULL);
632 		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
633 	}
634 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
635 	if (!pdata)
636 		return -ENOMEM;
637 
638 	INIT_LIST_HEAD(&resource_list);
639 	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
640 	if (ret < 0)
641 		goto err_out;
642 
643 	list_for_each_entry(rentry, &resource_list, node)
644 		if (resource_type(rentry->res) == IORESOURCE_MEM) {
645 			if (dev_desc->prv_size_override)
646 				pdata->mmio_size = dev_desc->prv_size_override;
647 			else
648 				pdata->mmio_size = resource_size(rentry->res);
649 			pdata->mmio_base = ioremap(rentry->res->start,
650 						   pdata->mmio_size);
651 			break;
652 		}
653 
654 	acpi_dev_free_resource_list(&resource_list);
655 
656 	if (!pdata->mmio_base) {
657 		/* Avoid acpi_bus_attach() instantiating a pdev for this dev. */
658 		adev->pnp.type.platform_id = 0;
659 		/* Skip the device, but continue the namespace scan. */
660 		ret = 0;
661 		goto err_out;
662 	}
663 
664 	pdata->adev = adev;
665 	pdata->dev_desc = dev_desc;
666 
667 	if (dev_desc->setup)
668 		dev_desc->setup(pdata);
669 
670 	if (dev_desc->flags & LPSS_CLK) {
671 		ret = register_device_clock(adev, pdata);
672 		if (ret) {
673 			/* Skip the device, but continue the namespace scan. */
674 			ret = 0;
675 			goto err_out;
676 		}
677 	}
678 
679 	/*
680 	 * This works around a known issue in ACPI tables where LPSS devices
681 	 * have _PS0 and _PS3 without _PSC (and no power resources), so
682 	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
683 	 */
684 	acpi_device_fix_up_power(adev);
685 
686 	adev->driver_data = pdata;
687 	pdev = acpi_create_platform_device(adev, dev_desc->properties);
688 	if (!IS_ERR_OR_NULL(pdev)) {
689 		acpi_lpss_create_device_links(adev, pdev);
690 		return 1;
691 	}
692 
693 	ret = PTR_ERR(pdev);
694 	adev->driver_data = NULL;
695 
696  err_out:
697 	kfree(pdata);
698 	return ret;
699 }
700 
701 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
702 {
703 	return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
704 }
705 
706 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
707 			     unsigned int reg)
708 {
709 	writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
710 }
711 
712 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
713 {
714 	struct acpi_device *adev;
715 	struct lpss_private_data *pdata;
716 	unsigned long flags;
717 	int ret;
718 
719 	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
720 	if (WARN_ON(ret))
721 		return ret;
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 
735  out:
736 	spin_unlock_irqrestore(&dev->power.lock, flags);
737 	return ret;
738 }
739 
740 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
741 			     char *buf)
742 {
743 	u32 ltr_value = 0;
744 	unsigned int reg;
745 	int ret;
746 
747 	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
748 	ret = lpss_reg_read(dev, reg, &ltr_value);
749 	if (ret)
750 		return ret;
751 
752 	return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
753 }
754 
755 static ssize_t lpss_ltr_mode_show(struct device *dev,
756 				  struct device_attribute *attr, char *buf)
757 {
758 	u32 ltr_mode = 0;
759 	char *outstr;
760 	int ret;
761 
762 	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
763 	if (ret)
764 		return ret;
765 
766 	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
767 	return sprintf(buf, "%s\n", outstr);
768 }
769 
770 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
771 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
772 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
773 
774 static struct attribute *lpss_attrs[] = {
775 	&dev_attr_auto_ltr.attr,
776 	&dev_attr_sw_ltr.attr,
777 	&dev_attr_ltr_mode.attr,
778 	NULL,
779 };
780 
781 static const struct attribute_group lpss_attr_group = {
782 	.attrs = lpss_attrs,
783 	.name = "lpss_ltr",
784 };
785 
786 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
787 {
788 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
789 	u32 ltr_mode, ltr_val;
790 
791 	ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
792 	if (val < 0) {
793 		if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
794 			ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
795 			__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
796 		}
797 		return;
798 	}
799 	ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
800 	if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
801 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
802 		val = LPSS_LTR_MAX_VAL;
803 	} else if (val > LPSS_LTR_MAX_VAL) {
804 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
805 		val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
806 	} else {
807 		ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
808 	}
809 	ltr_val |= val;
810 	__lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
811 	if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
812 		ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
813 		__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
814 	}
815 }
816 
817 #ifdef CONFIG_PM
818 /**
819  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
820  * @dev: LPSS device
821  * @pdata: pointer to the private data of the LPSS device
822  *
823  * Most LPSS devices have private registers which may loose their context when
824  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
825  * prv_reg_ctx array.
826  */
827 static void acpi_lpss_save_ctx(struct device *dev,
828 			       struct lpss_private_data *pdata)
829 {
830 	unsigned int i;
831 
832 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
833 		unsigned long offset = i * sizeof(u32);
834 
835 		pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
836 		dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
837 			pdata->prv_reg_ctx[i], offset);
838 	}
839 }
840 
841 /**
842  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
843  * @dev: LPSS device
844  * @pdata: pointer to the private data of the LPSS device
845  *
846  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
847  */
848 static void acpi_lpss_restore_ctx(struct device *dev,
849 				  struct lpss_private_data *pdata)
850 {
851 	unsigned int i;
852 
853 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
854 		unsigned long offset = i * sizeof(u32);
855 
856 		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
857 		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
858 			pdata->prv_reg_ctx[i], offset);
859 	}
860 }
861 
862 static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
863 {
864 	/*
865 	 * The following delay is needed or the subsequent write operations may
866 	 * fail. The LPSS devices are actually PCI devices and the PCI spec
867 	 * expects 10ms delay before the device can be accessed after D3 to D0
868 	 * transition. However some platforms like BSW does not need this delay.
869 	 */
870 	unsigned int delay = 10;	/* default 10ms delay */
871 
872 	if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
873 		delay = 0;
874 
875 	msleep(delay);
876 }
877 
878 static int acpi_lpss_activate(struct device *dev)
879 {
880 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
881 	int ret;
882 
883 	ret = acpi_dev_resume(dev);
884 	if (ret)
885 		return ret;
886 
887 	acpi_lpss_d3_to_d0_delay(pdata);
888 
889 	/*
890 	 * This is called only on ->probe() stage where a device is either in
891 	 * known state defined by BIOS or most likely powered off. Due to this
892 	 * we have to deassert reset line to be sure that ->probe() will
893 	 * recognize the device.
894 	 */
895 	if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE))
896 		lpss_deassert_reset(pdata);
897 
898 #ifdef CONFIG_PM
899 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX_ONCE)
900 		acpi_lpss_save_ctx(dev, pdata);
901 #endif
902 
903 	return 0;
904 }
905 
906 static void acpi_lpss_dismiss(struct device *dev)
907 {
908 	acpi_dev_suspend(dev, false);
909 }
910 
911 /* IOSF SB for LPSS island */
912 #define LPSS_IOSF_UNIT_LPIOEP		0xA0
913 #define LPSS_IOSF_UNIT_LPIO1		0xAB
914 #define LPSS_IOSF_UNIT_LPIO2		0xAC
915 
916 #define LPSS_IOSF_PMCSR			0x84
917 #define LPSS_PMCSR_D0			0
918 #define LPSS_PMCSR_D3hot		3
919 #define LPSS_PMCSR_Dx_MASK		GENMASK(1, 0)
920 
921 #define LPSS_IOSF_GPIODEF0		0x154
922 #define LPSS_GPIODEF0_DMA1_D3		BIT(2)
923 #define LPSS_GPIODEF0_DMA2_D3		BIT(3)
924 #define LPSS_GPIODEF0_DMA_D3_MASK	GENMASK(3, 2)
925 #define LPSS_GPIODEF0_DMA_LLP		BIT(13)
926 
927 static DEFINE_MUTEX(lpss_iosf_mutex);
928 static bool lpss_iosf_d3_entered = true;
929 
930 static void lpss_iosf_enter_d3_state(void)
931 {
932 	u32 value1 = 0;
933 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
934 	u32 value2 = LPSS_PMCSR_D3hot;
935 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
936 	/*
937 	 * PMC provides an information about actual status of the LPSS devices.
938 	 * Here we read the values related to LPSS power island, i.e. LPSS
939 	 * devices, excluding both LPSS DMA controllers, along with SCC domain.
940 	 */
941 	u32 func_dis, d3_sts_0, pmc_status;
942 	int ret;
943 
944 	ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
945 	if (ret)
946 		return;
947 
948 	mutex_lock(&lpss_iosf_mutex);
949 
950 	ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
951 	if (ret)
952 		goto exit;
953 
954 	/*
955 	 * Get the status of entire LPSS power island per device basis.
956 	 * Shutdown both LPSS DMA controllers if and only if all other devices
957 	 * are already in D3hot.
958 	 */
959 	pmc_status = (~(d3_sts_0 | func_dis)) & pmc_atom_d3_mask;
960 	if (pmc_status)
961 		goto exit;
962 
963 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
964 			LPSS_IOSF_PMCSR, value2, mask2);
965 
966 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
967 			LPSS_IOSF_PMCSR, value2, mask2);
968 
969 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
970 			LPSS_IOSF_GPIODEF0, value1, mask1);
971 
972 	lpss_iosf_d3_entered = true;
973 
974 exit:
975 	mutex_unlock(&lpss_iosf_mutex);
976 }
977 
978 static void lpss_iosf_exit_d3_state(void)
979 {
980 	u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3 |
981 		     LPSS_GPIODEF0_DMA_LLP;
982 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
983 	u32 value2 = LPSS_PMCSR_D0;
984 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
985 
986 	mutex_lock(&lpss_iosf_mutex);
987 
988 	if (!lpss_iosf_d3_entered)
989 		goto exit;
990 
991 	lpss_iosf_d3_entered = false;
992 
993 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
994 			LPSS_IOSF_GPIODEF0, value1, mask1);
995 
996 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
997 			LPSS_IOSF_PMCSR, value2, mask2);
998 
999 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
1000 			LPSS_IOSF_PMCSR, value2, mask2);
1001 
1002 exit:
1003 	mutex_unlock(&lpss_iosf_mutex);
1004 }
1005 
1006 static int acpi_lpss_suspend(struct device *dev, bool wakeup)
1007 {
1008 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1009 	int ret;
1010 
1011 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
1012 		acpi_lpss_save_ctx(dev, pdata);
1013 
1014 	ret = acpi_dev_suspend(dev, wakeup);
1015 
1016 	/*
1017 	 * This call must be last in the sequence, otherwise PMC will return
1018 	 * wrong status for devices being about to be powered off. See
1019 	 * lpss_iosf_enter_d3_state() for further information.
1020 	 */
1021 	if (acpi_target_system_state() == ACPI_STATE_S0 &&
1022 	    lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1023 		lpss_iosf_enter_d3_state();
1024 
1025 	return ret;
1026 }
1027 
1028 static int acpi_lpss_resume(struct device *dev)
1029 {
1030 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1031 	int ret;
1032 
1033 	/*
1034 	 * This call is kept first to be in symmetry with
1035 	 * acpi_lpss_runtime_suspend() one.
1036 	 */
1037 	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1038 		lpss_iosf_exit_d3_state();
1039 
1040 	ret = acpi_dev_resume(dev);
1041 	if (ret)
1042 		return ret;
1043 
1044 	acpi_lpss_d3_to_d0_delay(pdata);
1045 
1046 	if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE))
1047 		acpi_lpss_restore_ctx(dev, pdata);
1048 
1049 	return 0;
1050 }
1051 
1052 #ifdef CONFIG_PM_SLEEP
1053 static int acpi_lpss_do_suspend_late(struct device *dev)
1054 {
1055 	int ret;
1056 
1057 	if (dev_pm_skip_suspend(dev))
1058 		return 0;
1059 
1060 	ret = pm_generic_suspend_late(dev);
1061 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1062 }
1063 
1064 static int acpi_lpss_suspend_late(struct device *dev)
1065 {
1066 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1067 
1068 	if (pdata->dev_desc->resume_from_noirq)
1069 		return 0;
1070 
1071 	return acpi_lpss_do_suspend_late(dev);
1072 }
1073 
1074 static int acpi_lpss_suspend_noirq(struct device *dev)
1075 {
1076 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1077 	int ret;
1078 
1079 	if (pdata->dev_desc->resume_from_noirq) {
1080 		/*
1081 		 * The driver's ->suspend_late callback will be invoked by
1082 		 * acpi_lpss_do_suspend_late(), with the assumption that the
1083 		 * driver really wanted to run that code in ->suspend_noirq, but
1084 		 * it could not run after acpi_dev_suspend() and the driver
1085 		 * expected the latter to be called in the "late" phase.
1086 		 */
1087 		ret = acpi_lpss_do_suspend_late(dev);
1088 		if (ret)
1089 			return ret;
1090 	}
1091 
1092 	return acpi_subsys_suspend_noirq(dev);
1093 }
1094 
1095 static int acpi_lpss_do_resume_early(struct device *dev)
1096 {
1097 	int ret = acpi_lpss_resume(dev);
1098 
1099 	return ret ? ret : pm_generic_resume_early(dev);
1100 }
1101 
1102 static int acpi_lpss_resume_early(struct device *dev)
1103 {
1104 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1105 
1106 	if (pdata->dev_desc->resume_from_noirq)
1107 		return 0;
1108 
1109 	if (dev_pm_skip_resume(dev))
1110 		return 0;
1111 
1112 	return acpi_lpss_do_resume_early(dev);
1113 }
1114 
1115 static int acpi_lpss_resume_noirq(struct device *dev)
1116 {
1117 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1118 	int ret;
1119 
1120 	/* Follow acpi_subsys_resume_noirq(). */
1121 	if (dev_pm_skip_resume(dev))
1122 		return 0;
1123 
1124 	ret = pm_generic_resume_noirq(dev);
1125 	if (ret)
1126 		return ret;
1127 
1128 	if (!pdata->dev_desc->resume_from_noirq)
1129 		return 0;
1130 
1131 	/*
1132 	 * The driver's ->resume_early callback will be invoked by
1133 	 * acpi_lpss_do_resume_early(), with the assumption that the driver
1134 	 * really wanted to run that code in ->resume_noirq, but it could not
1135 	 * run before acpi_dev_resume() and the driver expected the latter to be
1136 	 * called in the "early" phase.
1137 	 */
1138 	return acpi_lpss_do_resume_early(dev);
1139 }
1140 
1141 static int acpi_lpss_do_restore_early(struct device *dev)
1142 {
1143 	int ret = acpi_lpss_resume(dev);
1144 
1145 	return ret ? ret : pm_generic_restore_early(dev);
1146 }
1147 
1148 static int acpi_lpss_restore_early(struct device *dev)
1149 {
1150 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1151 
1152 	if (pdata->dev_desc->resume_from_noirq)
1153 		return 0;
1154 
1155 	return acpi_lpss_do_restore_early(dev);
1156 }
1157 
1158 static int acpi_lpss_restore_noirq(struct device *dev)
1159 {
1160 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1161 	int ret;
1162 
1163 	ret = pm_generic_restore_noirq(dev);
1164 	if (ret)
1165 		return ret;
1166 
1167 	if (!pdata->dev_desc->resume_from_noirq)
1168 		return 0;
1169 
1170 	/* This is analogous to what happens in acpi_lpss_resume_noirq(). */
1171 	return acpi_lpss_do_restore_early(dev);
1172 }
1173 
1174 static int acpi_lpss_do_poweroff_late(struct device *dev)
1175 {
1176 	int ret = pm_generic_poweroff_late(dev);
1177 
1178 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1179 }
1180 
1181 static int acpi_lpss_poweroff_late(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 		return 0;
1190 
1191 	return acpi_lpss_do_poweroff_late(dev);
1192 }
1193 
1194 static int acpi_lpss_poweroff_noirq(struct device *dev)
1195 {
1196 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1197 
1198 	if (dev_pm_skip_suspend(dev))
1199 		return 0;
1200 
1201 	if (pdata->dev_desc->resume_from_noirq) {
1202 		/* This is analogous to the acpi_lpss_suspend_noirq() case. */
1203 		int ret = acpi_lpss_do_poweroff_late(dev);
1204 
1205 		if (ret)
1206 			return ret;
1207 	}
1208 
1209 	return pm_generic_poweroff_noirq(dev);
1210 }
1211 #endif /* CONFIG_PM_SLEEP */
1212 
1213 static int acpi_lpss_runtime_suspend(struct device *dev)
1214 {
1215 	int ret = pm_generic_runtime_suspend(dev);
1216 
1217 	return ret ? ret : acpi_lpss_suspend(dev, true);
1218 }
1219 
1220 static int acpi_lpss_runtime_resume(struct device *dev)
1221 {
1222 	int ret = acpi_lpss_resume(dev);
1223 
1224 	return ret ? ret : pm_generic_runtime_resume(dev);
1225 }
1226 #endif /* CONFIG_PM */
1227 
1228 static struct dev_pm_domain acpi_lpss_pm_domain = {
1229 #ifdef CONFIG_PM
1230 	.activate = acpi_lpss_activate,
1231 	.dismiss = acpi_lpss_dismiss,
1232 #endif
1233 	.ops = {
1234 #ifdef CONFIG_PM
1235 #ifdef CONFIG_PM_SLEEP
1236 		.prepare = acpi_subsys_prepare,
1237 		.complete = acpi_subsys_complete,
1238 		.suspend = acpi_subsys_suspend,
1239 		.suspend_late = acpi_lpss_suspend_late,
1240 		.suspend_noirq = acpi_lpss_suspend_noirq,
1241 		.resume_noirq = acpi_lpss_resume_noirq,
1242 		.resume_early = acpi_lpss_resume_early,
1243 		.freeze = acpi_subsys_freeze,
1244 		.poweroff = acpi_subsys_poweroff,
1245 		.poweroff_late = acpi_lpss_poweroff_late,
1246 		.poweroff_noirq = acpi_lpss_poweroff_noirq,
1247 		.restore_noirq = acpi_lpss_restore_noirq,
1248 		.restore_early = acpi_lpss_restore_early,
1249 #endif
1250 		.runtime_suspend = acpi_lpss_runtime_suspend,
1251 		.runtime_resume = acpi_lpss_runtime_resume,
1252 #endif
1253 	},
1254 };
1255 
1256 static int acpi_lpss_platform_notify(struct notifier_block *nb,
1257 				     unsigned long action, void *data)
1258 {
1259 	struct platform_device *pdev = to_platform_device(data);
1260 	struct lpss_private_data *pdata;
1261 	struct acpi_device *adev;
1262 	const struct acpi_device_id *id;
1263 
1264 	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
1265 	if (!id || !id->driver_data)
1266 		return 0;
1267 
1268 	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
1269 		return 0;
1270 
1271 	pdata = acpi_driver_data(adev);
1272 	if (!pdata)
1273 		return 0;
1274 
1275 	if (pdata->mmio_base &&
1276 	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
1277 		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
1278 		return 0;
1279 	}
1280 
1281 	switch (action) {
1282 	case BUS_NOTIFY_BIND_DRIVER:
1283 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1284 		break;
1285 	case BUS_NOTIFY_DRIVER_NOT_BOUND:
1286 	case BUS_NOTIFY_UNBOUND_DRIVER:
1287 		dev_pm_domain_set(&pdev->dev, NULL);
1288 		break;
1289 	case BUS_NOTIFY_ADD_DEVICE:
1290 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1291 		if (pdata->dev_desc->flags & LPSS_LTR)
1292 			return sysfs_create_group(&pdev->dev.kobj,
1293 						  &lpss_attr_group);
1294 		break;
1295 	case BUS_NOTIFY_DEL_DEVICE:
1296 		if (pdata->dev_desc->flags & LPSS_LTR)
1297 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
1298 		dev_pm_domain_set(&pdev->dev, NULL);
1299 		break;
1300 	default:
1301 		break;
1302 	}
1303 
1304 	return 0;
1305 }
1306 
1307 static struct notifier_block acpi_lpss_nb = {
1308 	.notifier_call = acpi_lpss_platform_notify,
1309 };
1310 
1311 static void acpi_lpss_bind(struct device *dev)
1312 {
1313 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1314 
1315 	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
1316 		return;
1317 
1318 	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
1319 		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
1320 	else
1321 		dev_err(dev, "MMIO size insufficient to access LTR\n");
1322 }
1323 
1324 static void acpi_lpss_unbind(struct device *dev)
1325 {
1326 	dev->power.set_latency_tolerance = NULL;
1327 }
1328 
1329 static struct acpi_scan_handler lpss_handler = {
1330 	.ids = acpi_lpss_device_ids,
1331 	.attach = acpi_lpss_create_device,
1332 	.bind = acpi_lpss_bind,
1333 	.unbind = acpi_lpss_unbind,
1334 };
1335 
1336 void __init acpi_lpss_init(void)
1337 {
1338 	const struct x86_cpu_id *id;
1339 	int ret;
1340 
1341 	ret = lpt_clk_init();
1342 	if (ret)
1343 		return;
1344 
1345 	id = x86_match_cpu(lpss_cpu_ids);
1346 	if (id)
1347 		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
1348 
1349 	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
1350 	acpi_scan_add_handler(&lpss_handler);
1351 }
1352 
1353 #else
1354 
1355 static struct acpi_scan_handler lpss_handler = {
1356 	.ids = acpi_lpss_device_ids,
1357 };
1358 
1359 void __init acpi_lpss_init(void)
1360 {
1361 	acpi_scan_add_handler(&lpss_handler);
1362 }
1363 
1364 #endif /* CONFIG_X86_INTEL_LPSS */
1365