xref: /openbmc/linux/drivers/acpi/acpi_lpss.c (revision 808643ea)
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-lpt", -1, NULL, 0);
389 }
390 
391 static int register_device_clock(struct acpi_device *adev,
392 				 struct lpss_private_data *pdata)
393 {
394 	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
395 	const char *devname = dev_name(&adev->dev);
396 	struct clk *clk;
397 	struct lpss_clk_data *clk_data;
398 	const char *parent, *clk_name;
399 	void __iomem *prv_base;
400 
401 	if (!lpss_clk_dev)
402 		lpt_register_clock_device();
403 
404 	clk_data = platform_get_drvdata(lpss_clk_dev);
405 	if (!clk_data)
406 		return -ENODEV;
407 	clk = clk_data->clk;
408 
409 	if (!pdata->mmio_base
410 	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
411 		return -ENODATA;
412 
413 	parent = clk_data->name;
414 	prv_base = pdata->mmio_base + dev_desc->prv_offset;
415 
416 	if (pdata->fixed_clk_rate) {
417 		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
418 					      pdata->fixed_clk_rate);
419 		goto out;
420 	}
421 
422 	if (dev_desc->flags & LPSS_CLK_GATE) {
423 		clk = clk_register_gate(NULL, devname, parent, 0,
424 					prv_base, 0, 0, NULL);
425 		parent = devname;
426 	}
427 
428 	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
429 		/* Prevent division by zero */
430 		if (!readl(prv_base))
431 			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
432 
433 		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
434 		if (!clk_name)
435 			return -ENOMEM;
436 		clk = clk_register_fractional_divider(NULL, clk_name, parent,
437 						      0, prv_base,
438 						      1, 15, 16, 15, 0, NULL);
439 		parent = clk_name;
440 
441 		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
442 		if (!clk_name) {
443 			kfree(parent);
444 			return -ENOMEM;
445 		}
446 		clk = clk_register_gate(NULL, clk_name, parent,
447 					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
448 					prv_base, 31, 0, NULL);
449 		kfree(parent);
450 		kfree(clk_name);
451 	}
452 out:
453 	if (IS_ERR(clk))
454 		return PTR_ERR(clk);
455 
456 	pdata->clk = clk;
457 	clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
458 	return 0;
459 }
460 
461 struct lpss_device_links {
462 	const char *supplier_hid;
463 	const char *supplier_uid;
464 	const char *consumer_hid;
465 	const char *consumer_uid;
466 	u32 flags;
467 	const struct dmi_system_id *dep_missing_ids;
468 };
469 
470 /* Please keep this list sorted alphabetically by vendor and model */
471 static const struct dmi_system_id i2c1_dep_missing_dmi_ids[] = {
472 	{
473 		.matches = {
474 			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
475 			DMI_MATCH(DMI_PRODUCT_NAME, "T200TA"),
476 		},
477 	},
478 	{}
479 };
480 
481 /*
482  * The _DEP method is used to identify dependencies but instead of creating
483  * device links for every handle in _DEP, only links in the following list are
484  * created. That is necessary because, in the general case, _DEP can refer to
485  * devices that might not have drivers, or that are on different buses, or where
486  * the supplier is not enumerated until after the consumer is probed.
487  */
488 static const struct lpss_device_links lpss_device_links[] = {
489 	/* CHT External sdcard slot controller depends on PMIC I2C ctrl */
490 	{"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME},
491 	/* CHT iGPU depends on PMIC I2C controller */
492 	{"808622C1", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
493 	/* BYT iGPU depends on the Embedded Controller I2C controller (UID 1) */
494 	{"80860F41", "1", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME,
495 	 i2c1_dep_missing_dmi_ids},
496 	/* BYT CR iGPU depends on PMIC I2C controller (UID 5 on CR) */
497 	{"80860F41", "5", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
498 	/* BYT iGPU depends on PMIC I2C controller (UID 7 on non CR) */
499 	{"80860F41", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
500 };
501 
502 static bool acpi_lpss_is_supplier(struct acpi_device *adev,
503 				  const struct lpss_device_links *link)
504 {
505 	return acpi_dev_hid_uid_match(adev, link->supplier_hid, link->supplier_uid);
506 }
507 
508 static bool acpi_lpss_is_consumer(struct acpi_device *adev,
509 				  const struct lpss_device_links *link)
510 {
511 	return acpi_dev_hid_uid_match(adev, link->consumer_hid, link->consumer_uid);
512 }
513 
514 struct hid_uid {
515 	const char *hid;
516 	const char *uid;
517 };
518 
519 static int match_hid_uid(struct device *dev, const void *data)
520 {
521 	struct acpi_device *adev = ACPI_COMPANION(dev);
522 	const struct hid_uid *id = data;
523 
524 	if (!adev)
525 		return 0;
526 
527 	return acpi_dev_hid_uid_match(adev, id->hid, id->uid);
528 }
529 
530 static struct device *acpi_lpss_find_device(const char *hid, const char *uid)
531 {
532 	struct device *dev;
533 
534 	struct hid_uid data = {
535 		.hid = hid,
536 		.uid = uid,
537 	};
538 
539 	dev = bus_find_device(&platform_bus_type, NULL, &data, match_hid_uid);
540 	if (dev)
541 		return dev;
542 
543 	return bus_find_device(&pci_bus_type, NULL, &data, match_hid_uid);
544 }
545 
546 static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle)
547 {
548 	struct acpi_handle_list dep_devices;
549 	acpi_status status;
550 	int i;
551 
552 	if (!acpi_has_method(adev->handle, "_DEP"))
553 		return false;
554 
555 	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
556 					 &dep_devices);
557 	if (ACPI_FAILURE(status)) {
558 		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
559 		return false;
560 	}
561 
562 	for (i = 0; i < dep_devices.count; i++) {
563 		if (dep_devices.handles[i] == handle)
564 			return true;
565 	}
566 
567 	return false;
568 }
569 
570 static void acpi_lpss_link_consumer(struct device *dev1,
571 				    const struct lpss_device_links *link)
572 {
573 	struct device *dev2;
574 
575 	dev2 = acpi_lpss_find_device(link->consumer_hid, link->consumer_uid);
576 	if (!dev2)
577 		return;
578 
579 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
580 	    || acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1)))
581 		device_link_add(dev2, dev1, link->flags);
582 
583 	put_device(dev2);
584 }
585 
586 static void acpi_lpss_link_supplier(struct device *dev1,
587 				    const struct lpss_device_links *link)
588 {
589 	struct device *dev2;
590 
591 	dev2 = acpi_lpss_find_device(link->supplier_hid, link->supplier_uid);
592 	if (!dev2)
593 		return;
594 
595 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
596 	    || acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2)))
597 		device_link_add(dev1, dev2, link->flags);
598 
599 	put_device(dev2);
600 }
601 
602 static void acpi_lpss_create_device_links(struct acpi_device *adev,
603 					  struct platform_device *pdev)
604 {
605 	int i;
606 
607 	for (i = 0; i < ARRAY_SIZE(lpss_device_links); i++) {
608 		const struct lpss_device_links *link = &lpss_device_links[i];
609 
610 		if (acpi_lpss_is_supplier(adev, link))
611 			acpi_lpss_link_consumer(&pdev->dev, link);
612 
613 		if (acpi_lpss_is_consumer(adev, link))
614 			acpi_lpss_link_supplier(&pdev->dev, link);
615 	}
616 }
617 
618 static int acpi_lpss_create_device(struct acpi_device *adev,
619 				   const struct acpi_device_id *id)
620 {
621 	const struct lpss_device_desc *dev_desc;
622 	struct lpss_private_data *pdata;
623 	struct resource_entry *rentry;
624 	struct list_head resource_list;
625 	struct platform_device *pdev;
626 	int ret;
627 
628 	dev_desc = (const struct lpss_device_desc *)id->driver_data;
629 	if (!dev_desc) {
630 		pdev = acpi_create_platform_device(adev, NULL);
631 		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
632 	}
633 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
634 	if (!pdata)
635 		return -ENOMEM;
636 
637 	INIT_LIST_HEAD(&resource_list);
638 	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
639 	if (ret < 0)
640 		goto err_out;
641 
642 	list_for_each_entry(rentry, &resource_list, node)
643 		if (resource_type(rentry->res) == IORESOURCE_MEM) {
644 			if (dev_desc->prv_size_override)
645 				pdata->mmio_size = dev_desc->prv_size_override;
646 			else
647 				pdata->mmio_size = resource_size(rentry->res);
648 			pdata->mmio_base = ioremap(rentry->res->start,
649 						   pdata->mmio_size);
650 			break;
651 		}
652 
653 	acpi_dev_free_resource_list(&resource_list);
654 
655 	if (!pdata->mmio_base) {
656 		/* Avoid acpi_bus_attach() instantiating a pdev for this dev. */
657 		adev->pnp.type.platform_id = 0;
658 		/* Skip the device, but continue the namespace scan. */
659 		ret = 0;
660 		goto err_out;
661 	}
662 
663 	pdata->adev = adev;
664 	pdata->dev_desc = dev_desc;
665 
666 	if (dev_desc->setup)
667 		dev_desc->setup(pdata);
668 
669 	if (dev_desc->flags & LPSS_CLK) {
670 		ret = register_device_clock(adev, pdata);
671 		if (ret) {
672 			/* Skip the device, but continue the namespace scan. */
673 			ret = 0;
674 			goto err_out;
675 		}
676 	}
677 
678 	/*
679 	 * This works around a known issue in ACPI tables where LPSS devices
680 	 * have _PS0 and _PS3 without _PSC (and no power resources), so
681 	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
682 	 */
683 	acpi_device_fix_up_power(adev);
684 
685 	adev->driver_data = pdata;
686 	pdev = acpi_create_platform_device(adev, dev_desc->properties);
687 	if (!IS_ERR_OR_NULL(pdev)) {
688 		acpi_lpss_create_device_links(adev, pdev);
689 		return 1;
690 	}
691 
692 	ret = PTR_ERR(pdev);
693 	adev->driver_data = NULL;
694 
695  err_out:
696 	kfree(pdata);
697 	return ret;
698 }
699 
700 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
701 {
702 	return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
703 }
704 
705 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
706 			     unsigned int reg)
707 {
708 	writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
709 }
710 
711 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
712 {
713 	struct acpi_device *adev;
714 	struct lpss_private_data *pdata;
715 	unsigned long flags;
716 	int ret;
717 
718 	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
719 	if (WARN_ON(ret))
720 		return ret;
721 
722 	spin_lock_irqsave(&dev->power.lock, flags);
723 	if (pm_runtime_suspended(dev)) {
724 		ret = -EAGAIN;
725 		goto out;
726 	}
727 	pdata = acpi_driver_data(adev);
728 	if (WARN_ON(!pdata || !pdata->mmio_base)) {
729 		ret = -ENODEV;
730 		goto out;
731 	}
732 	*val = __lpss_reg_read(pdata, reg);
733 
734  out:
735 	spin_unlock_irqrestore(&dev->power.lock, flags);
736 	return ret;
737 }
738 
739 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
740 			     char *buf)
741 {
742 	u32 ltr_value = 0;
743 	unsigned int reg;
744 	int ret;
745 
746 	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
747 	ret = lpss_reg_read(dev, reg, &ltr_value);
748 	if (ret)
749 		return ret;
750 
751 	return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
752 }
753 
754 static ssize_t lpss_ltr_mode_show(struct device *dev,
755 				  struct device_attribute *attr, char *buf)
756 {
757 	u32 ltr_mode = 0;
758 	char *outstr;
759 	int ret;
760 
761 	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
762 	if (ret)
763 		return ret;
764 
765 	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
766 	return sprintf(buf, "%s\n", outstr);
767 }
768 
769 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
770 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
771 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
772 
773 static struct attribute *lpss_attrs[] = {
774 	&dev_attr_auto_ltr.attr,
775 	&dev_attr_sw_ltr.attr,
776 	&dev_attr_ltr_mode.attr,
777 	NULL,
778 };
779 
780 static const struct attribute_group lpss_attr_group = {
781 	.attrs = lpss_attrs,
782 	.name = "lpss_ltr",
783 };
784 
785 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
786 {
787 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
788 	u32 ltr_mode, ltr_val;
789 
790 	ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
791 	if (val < 0) {
792 		if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
793 			ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
794 			__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
795 		}
796 		return;
797 	}
798 	ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
799 	if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
800 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
801 		val = LPSS_LTR_MAX_VAL;
802 	} else if (val > LPSS_LTR_MAX_VAL) {
803 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
804 		val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
805 	} else {
806 		ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
807 	}
808 	ltr_val |= val;
809 	__lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
810 	if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
811 		ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
812 		__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
813 	}
814 }
815 
816 #ifdef CONFIG_PM
817 /**
818  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
819  * @dev: LPSS device
820  * @pdata: pointer to the private data of the LPSS device
821  *
822  * Most LPSS devices have private registers which may loose their context when
823  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
824  * prv_reg_ctx array.
825  */
826 static void acpi_lpss_save_ctx(struct device *dev,
827 			       struct lpss_private_data *pdata)
828 {
829 	unsigned int i;
830 
831 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
832 		unsigned long offset = i * sizeof(u32);
833 
834 		pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
835 		dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
836 			pdata->prv_reg_ctx[i], offset);
837 	}
838 }
839 
840 /**
841  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
842  * @dev: LPSS device
843  * @pdata: pointer to the private data of the LPSS device
844  *
845  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
846  */
847 static void acpi_lpss_restore_ctx(struct device *dev,
848 				  struct lpss_private_data *pdata)
849 {
850 	unsigned int i;
851 
852 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
853 		unsigned long offset = i * sizeof(u32);
854 
855 		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
856 		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
857 			pdata->prv_reg_ctx[i], offset);
858 	}
859 }
860 
861 static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
862 {
863 	/*
864 	 * The following delay is needed or the subsequent write operations may
865 	 * fail. The LPSS devices are actually PCI devices and the PCI spec
866 	 * expects 10ms delay before the device can be accessed after D3 to D0
867 	 * transition. However some platforms like BSW does not need this delay.
868 	 */
869 	unsigned int delay = 10;	/* default 10ms delay */
870 
871 	if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
872 		delay = 0;
873 
874 	msleep(delay);
875 }
876 
877 static int acpi_lpss_activate(struct device *dev)
878 {
879 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
880 	int ret;
881 
882 	ret = acpi_dev_resume(dev);
883 	if (ret)
884 		return ret;
885 
886 	acpi_lpss_d3_to_d0_delay(pdata);
887 
888 	/*
889 	 * This is called only on ->probe() stage where a device is either in
890 	 * known state defined by BIOS or most likely powered off. Due to this
891 	 * we have to deassert reset line to be sure that ->probe() will
892 	 * recognize the device.
893 	 */
894 	if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE))
895 		lpss_deassert_reset(pdata);
896 
897 #ifdef CONFIG_PM
898 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX_ONCE)
899 		acpi_lpss_save_ctx(dev, pdata);
900 #endif
901 
902 	return 0;
903 }
904 
905 static void acpi_lpss_dismiss(struct device *dev)
906 {
907 	acpi_dev_suspend(dev, false);
908 }
909 
910 /* IOSF SB for LPSS island */
911 #define LPSS_IOSF_UNIT_LPIOEP		0xA0
912 #define LPSS_IOSF_UNIT_LPIO1		0xAB
913 #define LPSS_IOSF_UNIT_LPIO2		0xAC
914 
915 #define LPSS_IOSF_PMCSR			0x84
916 #define LPSS_PMCSR_D0			0
917 #define LPSS_PMCSR_D3hot		3
918 #define LPSS_PMCSR_Dx_MASK		GENMASK(1, 0)
919 
920 #define LPSS_IOSF_GPIODEF0		0x154
921 #define LPSS_GPIODEF0_DMA1_D3		BIT(2)
922 #define LPSS_GPIODEF0_DMA2_D3		BIT(3)
923 #define LPSS_GPIODEF0_DMA_D3_MASK	GENMASK(3, 2)
924 #define LPSS_GPIODEF0_DMA_LLP		BIT(13)
925 
926 static DEFINE_MUTEX(lpss_iosf_mutex);
927 static bool lpss_iosf_d3_entered = true;
928 
929 static void lpss_iosf_enter_d3_state(void)
930 {
931 	u32 value1 = 0;
932 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
933 	u32 value2 = LPSS_PMCSR_D3hot;
934 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
935 	/*
936 	 * PMC provides an information about actual status of the LPSS devices.
937 	 * Here we read the values related to LPSS power island, i.e. LPSS
938 	 * devices, excluding both LPSS DMA controllers, along with SCC domain.
939 	 */
940 	u32 func_dis, d3_sts_0, pmc_status;
941 	int ret;
942 
943 	ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
944 	if (ret)
945 		return;
946 
947 	mutex_lock(&lpss_iosf_mutex);
948 
949 	ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
950 	if (ret)
951 		goto exit;
952 
953 	/*
954 	 * Get the status of entire LPSS power island per device basis.
955 	 * Shutdown both LPSS DMA controllers if and only if all other devices
956 	 * are already in D3hot.
957 	 */
958 	pmc_status = (~(d3_sts_0 | func_dis)) & pmc_atom_d3_mask;
959 	if (pmc_status)
960 		goto exit;
961 
962 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
963 			LPSS_IOSF_PMCSR, value2, mask2);
964 
965 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
966 			LPSS_IOSF_PMCSR, value2, mask2);
967 
968 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
969 			LPSS_IOSF_GPIODEF0, value1, mask1);
970 
971 	lpss_iosf_d3_entered = true;
972 
973 exit:
974 	mutex_unlock(&lpss_iosf_mutex);
975 }
976 
977 static void lpss_iosf_exit_d3_state(void)
978 {
979 	u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3 |
980 		     LPSS_GPIODEF0_DMA_LLP;
981 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
982 	u32 value2 = LPSS_PMCSR_D0;
983 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
984 
985 	mutex_lock(&lpss_iosf_mutex);
986 
987 	if (!lpss_iosf_d3_entered)
988 		goto exit;
989 
990 	lpss_iosf_d3_entered = false;
991 
992 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
993 			LPSS_IOSF_GPIODEF0, value1, mask1);
994 
995 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
996 			LPSS_IOSF_PMCSR, value2, mask2);
997 
998 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
999 			LPSS_IOSF_PMCSR, value2, mask2);
1000 
1001 exit:
1002 	mutex_unlock(&lpss_iosf_mutex);
1003 }
1004 
1005 static int acpi_lpss_suspend(struct device *dev, bool wakeup)
1006 {
1007 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1008 	int ret;
1009 
1010 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
1011 		acpi_lpss_save_ctx(dev, pdata);
1012 
1013 	ret = acpi_dev_suspend(dev, wakeup);
1014 
1015 	/*
1016 	 * This call must be last in the sequence, otherwise PMC will return
1017 	 * wrong status for devices being about to be powered off. See
1018 	 * lpss_iosf_enter_d3_state() for further information.
1019 	 */
1020 	if (acpi_target_system_state() == ACPI_STATE_S0 &&
1021 	    lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1022 		lpss_iosf_enter_d3_state();
1023 
1024 	return ret;
1025 }
1026 
1027 static int acpi_lpss_resume(struct device *dev)
1028 {
1029 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1030 	int ret;
1031 
1032 	/*
1033 	 * This call is kept first to be in symmetry with
1034 	 * acpi_lpss_runtime_suspend() one.
1035 	 */
1036 	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1037 		lpss_iosf_exit_d3_state();
1038 
1039 	ret = acpi_dev_resume(dev);
1040 	if (ret)
1041 		return ret;
1042 
1043 	acpi_lpss_d3_to_d0_delay(pdata);
1044 
1045 	if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE))
1046 		acpi_lpss_restore_ctx(dev, pdata);
1047 
1048 	return 0;
1049 }
1050 
1051 #ifdef CONFIG_PM_SLEEP
1052 static int acpi_lpss_do_suspend_late(struct device *dev)
1053 {
1054 	int ret;
1055 
1056 	if (dev_pm_skip_suspend(dev))
1057 		return 0;
1058 
1059 	ret = pm_generic_suspend_late(dev);
1060 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1061 }
1062 
1063 static int acpi_lpss_suspend_late(struct device *dev)
1064 {
1065 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1066 
1067 	if (pdata->dev_desc->resume_from_noirq)
1068 		return 0;
1069 
1070 	return acpi_lpss_do_suspend_late(dev);
1071 }
1072 
1073 static int acpi_lpss_suspend_noirq(struct device *dev)
1074 {
1075 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1076 	int ret;
1077 
1078 	if (pdata->dev_desc->resume_from_noirq) {
1079 		/*
1080 		 * The driver's ->suspend_late callback will be invoked by
1081 		 * acpi_lpss_do_suspend_late(), with the assumption that the
1082 		 * driver really wanted to run that code in ->suspend_noirq, but
1083 		 * it could not run after acpi_dev_suspend() and the driver
1084 		 * expected the latter to be called in the "late" phase.
1085 		 */
1086 		ret = acpi_lpss_do_suspend_late(dev);
1087 		if (ret)
1088 			return ret;
1089 	}
1090 
1091 	return acpi_subsys_suspend_noirq(dev);
1092 }
1093 
1094 static int acpi_lpss_do_resume_early(struct device *dev)
1095 {
1096 	int ret = acpi_lpss_resume(dev);
1097 
1098 	return ret ? ret : pm_generic_resume_early(dev);
1099 }
1100 
1101 static int acpi_lpss_resume_early(struct device *dev)
1102 {
1103 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1104 
1105 	if (pdata->dev_desc->resume_from_noirq)
1106 		return 0;
1107 
1108 	if (dev_pm_skip_resume(dev))
1109 		return 0;
1110 
1111 	return acpi_lpss_do_resume_early(dev);
1112 }
1113 
1114 static int acpi_lpss_resume_noirq(struct device *dev)
1115 {
1116 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1117 	int ret;
1118 
1119 	/* Follow acpi_subsys_resume_noirq(). */
1120 	if (dev_pm_skip_resume(dev))
1121 		return 0;
1122 
1123 	ret = pm_generic_resume_noirq(dev);
1124 	if (ret)
1125 		return ret;
1126 
1127 	if (!pdata->dev_desc->resume_from_noirq)
1128 		return 0;
1129 
1130 	/*
1131 	 * The driver's ->resume_early callback will be invoked by
1132 	 * acpi_lpss_do_resume_early(), with the assumption that the driver
1133 	 * really wanted to run that code in ->resume_noirq, but it could not
1134 	 * run before acpi_dev_resume() and the driver expected the latter to be
1135 	 * called in the "early" phase.
1136 	 */
1137 	return acpi_lpss_do_resume_early(dev);
1138 }
1139 
1140 static int acpi_lpss_do_restore_early(struct device *dev)
1141 {
1142 	int ret = acpi_lpss_resume(dev);
1143 
1144 	return ret ? ret : pm_generic_restore_early(dev);
1145 }
1146 
1147 static int acpi_lpss_restore_early(struct device *dev)
1148 {
1149 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1150 
1151 	if (pdata->dev_desc->resume_from_noirq)
1152 		return 0;
1153 
1154 	return acpi_lpss_do_restore_early(dev);
1155 }
1156 
1157 static int acpi_lpss_restore_noirq(struct device *dev)
1158 {
1159 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1160 	int ret;
1161 
1162 	ret = pm_generic_restore_noirq(dev);
1163 	if (ret)
1164 		return ret;
1165 
1166 	if (!pdata->dev_desc->resume_from_noirq)
1167 		return 0;
1168 
1169 	/* This is analogous to what happens in acpi_lpss_resume_noirq(). */
1170 	return acpi_lpss_do_restore_early(dev);
1171 }
1172 
1173 static int acpi_lpss_do_poweroff_late(struct device *dev)
1174 {
1175 	int ret = pm_generic_poweroff_late(dev);
1176 
1177 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1178 }
1179 
1180 static int acpi_lpss_poweroff_late(struct device *dev)
1181 {
1182 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1183 
1184 	if (dev_pm_skip_suspend(dev))
1185 		return 0;
1186 
1187 	if (pdata->dev_desc->resume_from_noirq)
1188 		return 0;
1189 
1190 	return acpi_lpss_do_poweroff_late(dev);
1191 }
1192 
1193 static int acpi_lpss_poweroff_noirq(struct device *dev)
1194 {
1195 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1196 
1197 	if (dev_pm_skip_suspend(dev))
1198 		return 0;
1199 
1200 	if (pdata->dev_desc->resume_from_noirq) {
1201 		/* This is analogous to the acpi_lpss_suspend_noirq() case. */
1202 		int ret = acpi_lpss_do_poweroff_late(dev);
1203 
1204 		if (ret)
1205 			return ret;
1206 	}
1207 
1208 	return pm_generic_poweroff_noirq(dev);
1209 }
1210 #endif /* CONFIG_PM_SLEEP */
1211 
1212 static int acpi_lpss_runtime_suspend(struct device *dev)
1213 {
1214 	int ret = pm_generic_runtime_suspend(dev);
1215 
1216 	return ret ? ret : acpi_lpss_suspend(dev, true);
1217 }
1218 
1219 static int acpi_lpss_runtime_resume(struct device *dev)
1220 {
1221 	int ret = acpi_lpss_resume(dev);
1222 
1223 	return ret ? ret : pm_generic_runtime_resume(dev);
1224 }
1225 #endif /* CONFIG_PM */
1226 
1227 static struct dev_pm_domain acpi_lpss_pm_domain = {
1228 #ifdef CONFIG_PM
1229 	.activate = acpi_lpss_activate,
1230 	.dismiss = acpi_lpss_dismiss,
1231 #endif
1232 	.ops = {
1233 #ifdef CONFIG_PM
1234 #ifdef CONFIG_PM_SLEEP
1235 		.prepare = acpi_subsys_prepare,
1236 		.complete = acpi_subsys_complete,
1237 		.suspend = acpi_subsys_suspend,
1238 		.suspend_late = acpi_lpss_suspend_late,
1239 		.suspend_noirq = acpi_lpss_suspend_noirq,
1240 		.resume_noirq = acpi_lpss_resume_noirq,
1241 		.resume_early = acpi_lpss_resume_early,
1242 		.freeze = acpi_subsys_freeze,
1243 		.poweroff = acpi_subsys_poweroff,
1244 		.poweroff_late = acpi_lpss_poweroff_late,
1245 		.poweroff_noirq = acpi_lpss_poweroff_noirq,
1246 		.restore_noirq = acpi_lpss_restore_noirq,
1247 		.restore_early = acpi_lpss_restore_early,
1248 #endif
1249 		.runtime_suspend = acpi_lpss_runtime_suspend,
1250 		.runtime_resume = acpi_lpss_runtime_resume,
1251 #endif
1252 	},
1253 };
1254 
1255 static int acpi_lpss_platform_notify(struct notifier_block *nb,
1256 				     unsigned long action, void *data)
1257 {
1258 	struct platform_device *pdev = to_platform_device(data);
1259 	struct lpss_private_data *pdata;
1260 	struct acpi_device *adev;
1261 	const struct acpi_device_id *id;
1262 
1263 	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
1264 	if (!id || !id->driver_data)
1265 		return 0;
1266 
1267 	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
1268 		return 0;
1269 
1270 	pdata = acpi_driver_data(adev);
1271 	if (!pdata)
1272 		return 0;
1273 
1274 	if (pdata->mmio_base &&
1275 	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
1276 		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
1277 		return 0;
1278 	}
1279 
1280 	switch (action) {
1281 	case BUS_NOTIFY_BIND_DRIVER:
1282 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1283 		break;
1284 	case BUS_NOTIFY_DRIVER_NOT_BOUND:
1285 	case BUS_NOTIFY_UNBOUND_DRIVER:
1286 		dev_pm_domain_set(&pdev->dev, NULL);
1287 		break;
1288 	case BUS_NOTIFY_ADD_DEVICE:
1289 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1290 		if (pdata->dev_desc->flags & LPSS_LTR)
1291 			return sysfs_create_group(&pdev->dev.kobj,
1292 						  &lpss_attr_group);
1293 		break;
1294 	case BUS_NOTIFY_DEL_DEVICE:
1295 		if (pdata->dev_desc->flags & LPSS_LTR)
1296 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
1297 		dev_pm_domain_set(&pdev->dev, NULL);
1298 		break;
1299 	default:
1300 		break;
1301 	}
1302 
1303 	return 0;
1304 }
1305 
1306 static struct notifier_block acpi_lpss_nb = {
1307 	.notifier_call = acpi_lpss_platform_notify,
1308 };
1309 
1310 static void acpi_lpss_bind(struct device *dev)
1311 {
1312 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1313 
1314 	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
1315 		return;
1316 
1317 	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
1318 		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
1319 	else
1320 		dev_err(dev, "MMIO size insufficient to access LTR\n");
1321 }
1322 
1323 static void acpi_lpss_unbind(struct device *dev)
1324 {
1325 	dev->power.set_latency_tolerance = NULL;
1326 }
1327 
1328 static struct acpi_scan_handler lpss_handler = {
1329 	.ids = acpi_lpss_device_ids,
1330 	.attach = acpi_lpss_create_device,
1331 	.bind = acpi_lpss_bind,
1332 	.unbind = acpi_lpss_unbind,
1333 };
1334 
1335 void __init acpi_lpss_init(void)
1336 {
1337 	const struct x86_cpu_id *id;
1338 	int ret;
1339 
1340 	ret = lpt_clk_init();
1341 	if (ret)
1342 		return;
1343 
1344 	id = x86_match_cpu(lpss_cpu_ids);
1345 	if (id)
1346 		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
1347 
1348 	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
1349 	acpi_scan_add_handler(&lpss_handler);
1350 }
1351 
1352 #else
1353 
1354 static struct acpi_scan_handler lpss_handler = {
1355 	.ids = acpi_lpss_device_ids,
1356 };
1357 
1358 void __init acpi_lpss_init(void)
1359 {
1360 	acpi_scan_add_handler(&lpss_handler);
1361 }
1362 
1363 #endif /* CONFIG_X86_INTEL_LPSS */
1364