xref: /openbmc/linux/drivers/acpi/acpi_lpss.c (revision 1ec7ccb4)
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/pxa2xx_ssp.h>
25 #include <linux/suspend.h>
26 #include <linux/delay.h>
27 
28 #include "internal.h"
29 
30 #ifdef CONFIG_X86_INTEL_LPSS
31 
32 #include <asm/cpu_device_id.h>
33 #include <asm/intel-family.h>
34 #include <asm/iosf_mbi.h>
35 
36 #define LPSS_ADDR(desc) ((unsigned long)&desc)
37 
38 #define LPSS_CLK_SIZE	0x04
39 #define LPSS_LTR_SIZE	0x18
40 
41 /* Offsets relative to LPSS_PRIVATE_OFFSET */
42 #define LPSS_CLK_DIVIDER_DEF_MASK	(BIT(1) | BIT(16))
43 #define LPSS_RESETS			0x04
44 #define LPSS_RESETS_RESET_FUNC		BIT(0)
45 #define LPSS_RESETS_RESET_APB		BIT(1)
46 #define LPSS_GENERAL			0x08
47 #define LPSS_GENERAL_LTR_MODE_SW	BIT(2)
48 #define LPSS_GENERAL_UART_RTS_OVRD	BIT(3)
49 #define LPSS_SW_LTR			0x10
50 #define LPSS_AUTO_LTR			0x14
51 #define LPSS_LTR_SNOOP_REQ		BIT(15)
52 #define LPSS_LTR_SNOOP_MASK		0x0000FFFF
53 #define LPSS_LTR_SNOOP_LAT_1US		0x800
54 #define LPSS_LTR_SNOOP_LAT_32US		0xC00
55 #define LPSS_LTR_SNOOP_LAT_SHIFT	5
56 #define LPSS_LTR_SNOOP_LAT_CUTOFF	3000
57 #define LPSS_LTR_MAX_VAL		0x3FF
58 #define LPSS_TX_INT			0x20
59 #define LPSS_TX_INT_MASK		BIT(1)
60 
61 #define LPSS_PRV_REG_COUNT		9
62 
63 /* LPSS Flags */
64 #define LPSS_CLK			BIT(0)
65 #define LPSS_CLK_GATE			BIT(1)
66 #define LPSS_CLK_DIVIDER		BIT(2)
67 #define LPSS_LTR			BIT(3)
68 #define LPSS_SAVE_CTX			BIT(4)
69 /*
70  * For some devices the DSDT AML code for another device turns off the device
71  * before our suspend handler runs, causing us to read/save all 1-s (0xffffffff)
72  * as ctx register values.
73  * Luckily these devices always use the same ctx register values, so we can
74  * work around this by saving the ctx registers once on activation.
75  */
76 #define LPSS_SAVE_CTX_ONCE		BIT(5)
77 #define LPSS_NO_D3_DELAY		BIT(6)
78 
79 struct lpss_private_data;
80 
81 struct lpss_device_desc {
82 	unsigned int flags;
83 	const char *clk_con_id;
84 	unsigned int prv_offset;
85 	size_t prv_size_override;
86 	const struct property_entry *properties;
87 	void (*setup)(struct lpss_private_data *pdata);
88 	bool resume_from_noirq;
89 };
90 
91 static const struct lpss_device_desc lpss_dma_desc = {
92 	.flags = LPSS_CLK,
93 };
94 
95 struct lpss_private_data {
96 	struct acpi_device *adev;
97 	void __iomem *mmio_base;
98 	resource_size_t mmio_size;
99 	unsigned int fixed_clk_rate;
100 	struct clk *clk;
101 	const struct lpss_device_desc *dev_desc;
102 	u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
103 };
104 
105 /* Devices which need to be in D3 before lpss_iosf_enter_d3_state() proceeds */
106 static u32 pmc_atom_d3_mask = 0xfe000ffe;
107 
108 /* LPSS run time quirks */
109 static unsigned int lpss_quirks;
110 
111 /*
112  * LPSS_QUIRK_ALWAYS_POWER_ON: override power state for LPSS DMA device.
113  *
114  * The LPSS DMA controller has neither _PS0 nor _PS3 method. Moreover
115  * it can be powered off automatically whenever the last LPSS device goes down.
116  * In case of no power any access to the DMA controller will hang the system.
117  * The behaviour is reproduced on some HP laptops based on Intel BayTrail as
118  * well as on ASuS T100TA transformer.
119  *
120  * This quirk overrides power state of entire LPSS island to keep DMA powered
121  * on whenever we have at least one other device in use.
122  */
123 #define LPSS_QUIRK_ALWAYS_POWER_ON	BIT(0)
124 
125 /* UART Component Parameter Register */
126 #define LPSS_UART_CPR			0xF4
127 #define LPSS_UART_CPR_AFCE		BIT(4)
128 
129 static void lpss_uart_setup(struct lpss_private_data *pdata)
130 {
131 	unsigned int offset;
132 	u32 val;
133 
134 	offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
135 	val = readl(pdata->mmio_base + offset);
136 	writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
137 
138 	val = readl(pdata->mmio_base + LPSS_UART_CPR);
139 	if (!(val & LPSS_UART_CPR_AFCE)) {
140 		offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
141 		val = readl(pdata->mmio_base + offset);
142 		val |= LPSS_GENERAL_UART_RTS_OVRD;
143 		writel(val, pdata->mmio_base + offset);
144 	}
145 }
146 
147 static void lpss_deassert_reset(struct lpss_private_data *pdata)
148 {
149 	unsigned int offset;
150 	u32 val;
151 
152 	offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
153 	val = readl(pdata->mmio_base + offset);
154 	val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
155 	writel(val, pdata->mmio_base + offset);
156 }
157 
158 /*
159  * BYT PWM used for backlight control by the i915 driver on systems without
160  * the Crystal Cove PMIC.
161  */
162 static struct pwm_lookup byt_pwm_lookup[] = {
163 	PWM_LOOKUP_WITH_MODULE("80860F09:00", 0, "0000:00:02.0",
164 			       "pwm_soc_backlight", 0, PWM_POLARITY_NORMAL,
165 			       "pwm-lpss-platform"),
166 };
167 
168 static void byt_pwm_setup(struct lpss_private_data *pdata)
169 {
170 	u64 uid;
171 
172 	/* Only call pwm_add_table for the first PWM controller */
173 	if (acpi_dev_uid_to_integer(pdata->adev, &uid) || uid != 1)
174 		return;
175 
176 	pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup));
177 }
178 
179 #define LPSS_I2C_ENABLE			0x6c
180 
181 static void byt_i2c_setup(struct lpss_private_data *pdata)
182 {
183 	acpi_handle handle = pdata->adev->handle;
184 	unsigned long long shared_host = 0;
185 	acpi_status status;
186 	u64 uid;
187 
188 	/* Expected to always be successfull, but better safe then sorry */
189 	if (!acpi_dev_uid_to_integer(pdata->adev, &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 /*
205  * BSW PWM1 is used for backlight control by the i915 driver
206  * BSW PWM2 is used for backlight control for fixed (etched into the glass)
207  * touch controls on some models. These touch-controls have specialized
208  * drivers which know they need the "pwm_soc_lpss_2" con-id.
209  */
210 static struct pwm_lookup bsw_pwm_lookup[] = {
211 	PWM_LOOKUP_WITH_MODULE("80862288:00", 0, "0000:00:02.0",
212 			       "pwm_soc_backlight", 0, PWM_POLARITY_NORMAL,
213 			       "pwm-lpss-platform"),
214 	PWM_LOOKUP_WITH_MODULE("80862289:00", 0, NULL,
215 			       "pwm_soc_lpss_2", 0, PWM_POLARITY_NORMAL,
216 			       "pwm-lpss-platform"),
217 };
218 
219 static void bsw_pwm_setup(struct lpss_private_data *pdata)
220 {
221 	u64 uid;
222 
223 	/* Only call pwm_add_table for the first PWM controller */
224 	if (acpi_dev_uid_to_integer(pdata->adev, &uid) || uid != 1)
225 		return;
226 
227 	pwm_add_table(bsw_pwm_lookup, ARRAY_SIZE(bsw_pwm_lookup));
228 }
229 
230 static const struct property_entry lpt_spi_properties[] = {
231 	PROPERTY_ENTRY_U32("intel,spi-pxa2xx-type", LPSS_LPT_SSP),
232 	{ }
233 };
234 
235 static const struct lpss_device_desc lpt_spi_dev_desc = {
236 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR
237 			| LPSS_SAVE_CTX,
238 	.prv_offset = 0x800,
239 	.properties = lpt_spi_properties,
240 };
241 
242 static const struct lpss_device_desc lpt_i2c_dev_desc = {
243 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR | LPSS_SAVE_CTX,
244 	.prv_offset = 0x800,
245 };
246 
247 static struct property_entry uart_properties[] = {
248 	PROPERTY_ENTRY_U32("reg-io-width", 4),
249 	PROPERTY_ENTRY_U32("reg-shift", 2),
250 	PROPERTY_ENTRY_BOOL("snps,uart-16550-compatible"),
251 	{ },
252 };
253 
254 static const struct lpss_device_desc lpt_uart_dev_desc = {
255 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR
256 			| LPSS_SAVE_CTX,
257 	.clk_con_id = "baudclk",
258 	.prv_offset = 0x800,
259 	.setup = lpss_uart_setup,
260 	.properties = uart_properties,
261 };
262 
263 static const struct lpss_device_desc lpt_sdio_dev_desc = {
264 	.flags = LPSS_LTR,
265 	.prv_offset = 0x1000,
266 	.prv_size_override = 0x1018,
267 };
268 
269 static const struct lpss_device_desc byt_pwm_dev_desc = {
270 	.flags = LPSS_SAVE_CTX,
271 	.prv_offset = 0x800,
272 	.setup = byt_pwm_setup,
273 };
274 
275 static const struct lpss_device_desc bsw_pwm_dev_desc = {
276 	.flags = LPSS_SAVE_CTX_ONCE | LPSS_NO_D3_DELAY,
277 	.prv_offset = 0x800,
278 	.setup = bsw_pwm_setup,
279 	.resume_from_noirq = true,
280 };
281 
282 static const struct lpss_device_desc bsw_pwm2_dev_desc = {
283 	.flags = LPSS_SAVE_CTX_ONCE | LPSS_NO_D3_DELAY,
284 	.prv_offset = 0x800,
285 	.resume_from_noirq = true,
286 };
287 
288 static const struct lpss_device_desc byt_uart_dev_desc = {
289 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
290 	.clk_con_id = "baudclk",
291 	.prv_offset = 0x800,
292 	.setup = lpss_uart_setup,
293 	.properties = uart_properties,
294 };
295 
296 static const struct lpss_device_desc bsw_uart_dev_desc = {
297 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
298 			| LPSS_NO_D3_DELAY,
299 	.clk_con_id = "baudclk",
300 	.prv_offset = 0x800,
301 	.setup = lpss_uart_setup,
302 	.properties = uart_properties,
303 };
304 
305 static const struct property_entry byt_spi_properties[] = {
306 	PROPERTY_ENTRY_U32("intel,spi-pxa2xx-type", LPSS_BYT_SSP),
307 	{ }
308 };
309 
310 static const struct lpss_device_desc byt_spi_dev_desc = {
311 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
312 	.prv_offset = 0x400,
313 	.properties = byt_spi_properties,
314 };
315 
316 static const struct lpss_device_desc byt_sdio_dev_desc = {
317 	.flags = LPSS_CLK,
318 };
319 
320 static const struct lpss_device_desc byt_i2c_dev_desc = {
321 	.flags = LPSS_CLK | LPSS_SAVE_CTX,
322 	.prv_offset = 0x800,
323 	.setup = byt_i2c_setup,
324 	.resume_from_noirq = true,
325 };
326 
327 static const struct lpss_device_desc bsw_i2c_dev_desc = {
328 	.flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
329 	.prv_offset = 0x800,
330 	.setup = byt_i2c_setup,
331 	.resume_from_noirq = true,
332 };
333 
334 static const struct property_entry bsw_spi_properties[] = {
335 	PROPERTY_ENTRY_U32("intel,spi-pxa2xx-type", LPSS_BSW_SSP),
336 	PROPERTY_ENTRY_U32("num-cs", 2),
337 	{ }
338 };
339 
340 static const struct lpss_device_desc bsw_spi_dev_desc = {
341 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
342 			| LPSS_NO_D3_DELAY,
343 	.prv_offset = 0x400,
344 	.setup = lpss_deassert_reset,
345 	.properties = bsw_spi_properties,
346 };
347 
348 static const struct x86_cpu_id lpss_cpu_ids[] = {
349 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT,	NULL),
350 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT,	NULL),
351 	{}
352 };
353 
354 #else
355 
356 #define LPSS_ADDR(desc) (0UL)
357 
358 #endif /* CONFIG_X86_INTEL_LPSS */
359 
360 static const struct acpi_device_id acpi_lpss_device_ids[] = {
361 	/* Generic LPSS devices */
362 	{ "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
363 
364 	/* Lynxpoint LPSS devices */
365 	{ "INT33C0", LPSS_ADDR(lpt_spi_dev_desc) },
366 	{ "INT33C1", LPSS_ADDR(lpt_spi_dev_desc) },
367 	{ "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
368 	{ "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
369 	{ "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
370 	{ "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
371 	{ "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
372 	{ "INT33C7", },
373 
374 	/* BayTrail LPSS devices */
375 	{ "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
376 	{ "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
377 	{ "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
378 	{ "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
379 	{ "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
380 	{ "INT33B2", },
381 	{ "INT33FC", },
382 
383 	/* Braswell LPSS devices */
384 	{ "80862286", LPSS_ADDR(lpss_dma_desc) },
385 	{ "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
386 	{ "80862289", LPSS_ADDR(bsw_pwm2_dev_desc) },
387 	{ "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
388 	{ "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
389 	{ "808622C0", LPSS_ADDR(lpss_dma_desc) },
390 	{ "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
391 
392 	/* Broadwell LPSS devices */
393 	{ "INT3430", LPSS_ADDR(lpt_spi_dev_desc) },
394 	{ "INT3431", LPSS_ADDR(lpt_spi_dev_desc) },
395 	{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
396 	{ "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
397 	{ "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
398 	{ "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
399 	{ "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
400 	{ "INT3437", },
401 
402 	/* Wildcat Point LPSS devices */
403 	{ "INT3438", LPSS_ADDR(lpt_spi_dev_desc) },
404 
405 	{ }
406 };
407 
408 #ifdef CONFIG_X86_INTEL_LPSS
409 
410 /* LPSS main clock device. */
411 static struct platform_device *lpss_clk_dev;
412 
413 static inline void lpt_register_clock_device(void)
414 {
415 	lpss_clk_dev = platform_device_register_simple("clk-lpss-atom",
416 						       PLATFORM_DEVID_NONE,
417 						       NULL, 0);
418 }
419 
420 static int register_device_clock(struct acpi_device *adev,
421 				 struct lpss_private_data *pdata)
422 {
423 	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
424 	const char *devname = dev_name(&adev->dev);
425 	struct clk *clk;
426 	struct lpss_clk_data *clk_data;
427 	const char *parent, *clk_name;
428 	void __iomem *prv_base;
429 
430 	if (!lpss_clk_dev)
431 		lpt_register_clock_device();
432 
433 	if (IS_ERR(lpss_clk_dev))
434 		return PTR_ERR(lpss_clk_dev);
435 
436 	clk_data = platform_get_drvdata(lpss_clk_dev);
437 	if (!clk_data)
438 		return -ENODEV;
439 	clk = clk_data->clk;
440 
441 	if (!pdata->mmio_base
442 	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
443 		return -ENODATA;
444 
445 	parent = clk_data->name;
446 	prv_base = pdata->mmio_base + dev_desc->prv_offset;
447 
448 	if (pdata->fixed_clk_rate) {
449 		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
450 					      pdata->fixed_clk_rate);
451 		goto out;
452 	}
453 
454 	if (dev_desc->flags & LPSS_CLK_GATE) {
455 		clk = clk_register_gate(NULL, devname, parent, 0,
456 					prv_base, 0, 0, NULL);
457 		parent = devname;
458 	}
459 
460 	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
461 		/* Prevent division by zero */
462 		if (!readl(prv_base))
463 			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
464 
465 		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
466 		if (!clk_name)
467 			return -ENOMEM;
468 		clk = clk_register_fractional_divider(NULL, clk_name, parent,
469 						      0, prv_base, 1, 15, 16, 15,
470 						      CLK_FRAC_DIVIDER_POWER_OF_TWO_PS,
471 						      NULL);
472 		parent = clk_name;
473 
474 		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
475 		if (!clk_name) {
476 			kfree(parent);
477 			return -ENOMEM;
478 		}
479 		clk = clk_register_gate(NULL, clk_name, parent,
480 					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
481 					prv_base, 31, 0, NULL);
482 		kfree(parent);
483 		kfree(clk_name);
484 	}
485 out:
486 	if (IS_ERR(clk))
487 		return PTR_ERR(clk);
488 
489 	pdata->clk = clk;
490 	clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
491 	return 0;
492 }
493 
494 struct lpss_device_links {
495 	const char *supplier_hid;
496 	const char *supplier_uid;
497 	const char *consumer_hid;
498 	const char *consumer_uid;
499 	u32 flags;
500 	const struct dmi_system_id *dep_missing_ids;
501 };
502 
503 /* Please keep this list sorted alphabetically by vendor and model */
504 static const struct dmi_system_id i2c1_dep_missing_dmi_ids[] = {
505 	{
506 		.matches = {
507 			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
508 			DMI_MATCH(DMI_PRODUCT_NAME, "T200TA"),
509 		},
510 	},
511 	{}
512 };
513 
514 /*
515  * The _DEP method is used to identify dependencies but instead of creating
516  * device links for every handle in _DEP, only links in the following list are
517  * created. That is necessary because, in the general case, _DEP can refer to
518  * devices that might not have drivers, or that are on different buses, or where
519  * the supplier is not enumerated until after the consumer is probed.
520  */
521 static const struct lpss_device_links lpss_device_links[] = {
522 	/* CHT External sdcard slot controller depends on PMIC I2C ctrl */
523 	{"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME},
524 	/* CHT iGPU depends on PMIC I2C controller */
525 	{"808622C1", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
526 	/* BYT iGPU depends on the Embedded Controller I2C controller (UID 1) */
527 	{"80860F41", "1", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME,
528 	 i2c1_dep_missing_dmi_ids},
529 	/* BYT CR iGPU depends on PMIC I2C controller (UID 5 on CR) */
530 	{"80860F41", "5", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
531 	/* BYT iGPU depends on PMIC I2C controller (UID 7 on non CR) */
532 	{"80860F41", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME},
533 };
534 
535 static bool acpi_lpss_is_supplier(struct acpi_device *adev,
536 				  const struct lpss_device_links *link)
537 {
538 	return acpi_dev_hid_uid_match(adev, link->supplier_hid, link->supplier_uid);
539 }
540 
541 static bool acpi_lpss_is_consumer(struct acpi_device *adev,
542 				  const struct lpss_device_links *link)
543 {
544 	return acpi_dev_hid_uid_match(adev, link->consumer_hid, link->consumer_uid);
545 }
546 
547 struct hid_uid {
548 	const char *hid;
549 	const char *uid;
550 };
551 
552 static int match_hid_uid(struct device *dev, const void *data)
553 {
554 	struct acpi_device *adev = ACPI_COMPANION(dev);
555 	const struct hid_uid *id = data;
556 
557 	if (!adev)
558 		return 0;
559 
560 	return acpi_dev_hid_uid_match(adev, id->hid, id->uid);
561 }
562 
563 static struct device *acpi_lpss_find_device(const char *hid, const char *uid)
564 {
565 	struct device *dev;
566 
567 	struct hid_uid data = {
568 		.hid = hid,
569 		.uid = uid,
570 	};
571 
572 	dev = bus_find_device(&platform_bus_type, NULL, &data, match_hid_uid);
573 	if (dev)
574 		return dev;
575 
576 	return bus_find_device(&pci_bus_type, NULL, &data, match_hid_uid);
577 }
578 
579 static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle)
580 {
581 	struct acpi_handle_list dep_devices;
582 	acpi_status status;
583 	int i;
584 
585 	if (!acpi_has_method(adev->handle, "_DEP"))
586 		return false;
587 
588 	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
589 					 &dep_devices);
590 	if (ACPI_FAILURE(status)) {
591 		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
592 		return false;
593 	}
594 
595 	for (i = 0; i < dep_devices.count; i++) {
596 		if (dep_devices.handles[i] == handle)
597 			return true;
598 	}
599 
600 	return false;
601 }
602 
603 static void acpi_lpss_link_consumer(struct device *dev1,
604 				    const struct lpss_device_links *link)
605 {
606 	struct device *dev2;
607 
608 	dev2 = acpi_lpss_find_device(link->consumer_hid, link->consumer_uid);
609 	if (!dev2)
610 		return;
611 
612 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
613 	    || acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1)))
614 		device_link_add(dev2, dev1, link->flags);
615 
616 	put_device(dev2);
617 }
618 
619 static void acpi_lpss_link_supplier(struct device *dev1,
620 				    const struct lpss_device_links *link)
621 {
622 	struct device *dev2;
623 
624 	dev2 = acpi_lpss_find_device(link->supplier_hid, link->supplier_uid);
625 	if (!dev2)
626 		return;
627 
628 	if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids))
629 	    || acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2)))
630 		device_link_add(dev1, dev2, link->flags);
631 
632 	put_device(dev2);
633 }
634 
635 static void acpi_lpss_create_device_links(struct acpi_device *adev,
636 					  struct platform_device *pdev)
637 {
638 	int i;
639 
640 	for (i = 0; i < ARRAY_SIZE(lpss_device_links); i++) {
641 		const struct lpss_device_links *link = &lpss_device_links[i];
642 
643 		if (acpi_lpss_is_supplier(adev, link))
644 			acpi_lpss_link_consumer(&pdev->dev, link);
645 
646 		if (acpi_lpss_is_consumer(adev, link))
647 			acpi_lpss_link_supplier(&pdev->dev, link);
648 	}
649 }
650 
651 static int acpi_lpss_create_device(struct acpi_device *adev,
652 				   const struct acpi_device_id *id)
653 {
654 	const struct lpss_device_desc *dev_desc;
655 	struct lpss_private_data *pdata;
656 	struct resource_entry *rentry;
657 	struct list_head resource_list;
658 	struct platform_device *pdev;
659 	int ret;
660 
661 	dev_desc = (const struct lpss_device_desc *)id->driver_data;
662 	if (!dev_desc) {
663 		pdev = acpi_create_platform_device(adev, NULL);
664 		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
665 	}
666 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
667 	if (!pdata)
668 		return -ENOMEM;
669 
670 	INIT_LIST_HEAD(&resource_list);
671 	ret = acpi_dev_get_memory_resources(adev, &resource_list);
672 	if (ret < 0)
673 		goto err_out;
674 
675 	rentry = list_first_entry_or_null(&resource_list, struct resource_entry, node);
676 	if (rentry) {
677 		if (dev_desc->prv_size_override)
678 			pdata->mmio_size = dev_desc->prv_size_override;
679 		else
680 			pdata->mmio_size = resource_size(rentry->res);
681 		pdata->mmio_base = ioremap(rentry->res->start, pdata->mmio_size);
682 	}
683 
684 	acpi_dev_free_resource_list(&resource_list);
685 
686 	if (!pdata->mmio_base) {
687 		/* Avoid acpi_bus_attach() instantiating a pdev for this dev. */
688 		adev->pnp.type.platform_id = 0;
689 		goto out_free;
690 	}
691 
692 	pdata->adev = adev;
693 	pdata->dev_desc = dev_desc;
694 
695 	if (dev_desc->setup)
696 		dev_desc->setup(pdata);
697 
698 	if (dev_desc->flags & LPSS_CLK) {
699 		ret = register_device_clock(adev, pdata);
700 		if (ret)
701 			goto out_free;
702 	}
703 
704 	/*
705 	 * This works around a known issue in ACPI tables where LPSS devices
706 	 * have _PS0 and _PS3 without _PSC (and no power resources), so
707 	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
708 	 */
709 	acpi_device_fix_up_power(adev);
710 
711 	adev->driver_data = pdata;
712 	pdev = acpi_create_platform_device(adev, dev_desc->properties);
713 	if (IS_ERR_OR_NULL(pdev)) {
714 		adev->driver_data = NULL;
715 		ret = PTR_ERR(pdev);
716 		goto err_out;
717 	}
718 
719 	acpi_lpss_create_device_links(adev, pdev);
720 	return 1;
721 
722 out_free:
723 	/* Skip the device, but continue the namespace scan */
724 	ret = 0;
725 err_out:
726 	kfree(pdata);
727 	return ret;
728 }
729 
730 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
731 {
732 	return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
733 }
734 
735 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
736 			     unsigned int reg)
737 {
738 	writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
739 }
740 
741 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
742 {
743 	struct acpi_device *adev = ACPI_COMPANION(dev);
744 	struct lpss_private_data *pdata;
745 	unsigned long flags;
746 	int ret;
747 
748 	if (WARN_ON(!adev))
749 		return -ENODEV;
750 
751 	spin_lock_irqsave(&dev->power.lock, flags);
752 	if (pm_runtime_suspended(dev)) {
753 		ret = -EAGAIN;
754 		goto out;
755 	}
756 	pdata = acpi_driver_data(adev);
757 	if (WARN_ON(!pdata || !pdata->mmio_base)) {
758 		ret = -ENODEV;
759 		goto out;
760 	}
761 	*val = __lpss_reg_read(pdata, reg);
762 	ret = 0;
763 
764  out:
765 	spin_unlock_irqrestore(&dev->power.lock, flags);
766 	return ret;
767 }
768 
769 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
770 			     char *buf)
771 {
772 	u32 ltr_value = 0;
773 	unsigned int reg;
774 	int ret;
775 
776 	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
777 	ret = lpss_reg_read(dev, reg, &ltr_value);
778 	if (ret)
779 		return ret;
780 
781 	return sysfs_emit(buf, "%08x\n", ltr_value);
782 }
783 
784 static ssize_t lpss_ltr_mode_show(struct device *dev,
785 				  struct device_attribute *attr, char *buf)
786 {
787 	u32 ltr_mode = 0;
788 	char *outstr;
789 	int ret;
790 
791 	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
792 	if (ret)
793 		return ret;
794 
795 	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
796 	return sprintf(buf, "%s\n", outstr);
797 }
798 
799 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
800 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
801 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
802 
803 static struct attribute *lpss_attrs[] = {
804 	&dev_attr_auto_ltr.attr,
805 	&dev_attr_sw_ltr.attr,
806 	&dev_attr_ltr_mode.attr,
807 	NULL,
808 };
809 
810 static const struct attribute_group lpss_attr_group = {
811 	.attrs = lpss_attrs,
812 	.name = "lpss_ltr",
813 };
814 
815 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
816 {
817 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
818 	u32 ltr_mode, ltr_val;
819 
820 	ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
821 	if (val < 0) {
822 		if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
823 			ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
824 			__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
825 		}
826 		return;
827 	}
828 	ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
829 	if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
830 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
831 		val = LPSS_LTR_MAX_VAL;
832 	} else if (val > LPSS_LTR_MAX_VAL) {
833 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
834 		val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
835 	} else {
836 		ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
837 	}
838 	ltr_val |= val;
839 	__lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
840 	if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
841 		ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
842 		__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
843 	}
844 }
845 
846 #ifdef CONFIG_PM
847 /**
848  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
849  * @dev: LPSS device
850  * @pdata: pointer to the private data of the LPSS device
851  *
852  * Most LPSS devices have private registers which may loose their context when
853  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
854  * prv_reg_ctx array.
855  */
856 static void acpi_lpss_save_ctx(struct device *dev,
857 			       struct lpss_private_data *pdata)
858 {
859 	unsigned int i;
860 
861 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
862 		unsigned long offset = i * sizeof(u32);
863 
864 		pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
865 		dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
866 			pdata->prv_reg_ctx[i], offset);
867 	}
868 }
869 
870 /**
871  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
872  * @dev: LPSS device
873  * @pdata: pointer to the private data of the LPSS device
874  *
875  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
876  */
877 static void acpi_lpss_restore_ctx(struct device *dev,
878 				  struct lpss_private_data *pdata)
879 {
880 	unsigned int i;
881 
882 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
883 		unsigned long offset = i * sizeof(u32);
884 
885 		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
886 		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
887 			pdata->prv_reg_ctx[i], offset);
888 	}
889 }
890 
891 static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
892 {
893 	/*
894 	 * The following delay is needed or the subsequent write operations may
895 	 * fail. The LPSS devices are actually PCI devices and the PCI spec
896 	 * expects 10ms delay before the device can be accessed after D3 to D0
897 	 * transition. However some platforms like BSW does not need this delay.
898 	 */
899 	unsigned int delay = 10;	/* default 10ms delay */
900 
901 	if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
902 		delay = 0;
903 
904 	msleep(delay);
905 }
906 
907 static int acpi_lpss_activate(struct device *dev)
908 {
909 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
910 	int ret;
911 
912 	ret = acpi_dev_resume(dev);
913 	if (ret)
914 		return ret;
915 
916 	acpi_lpss_d3_to_d0_delay(pdata);
917 
918 	/*
919 	 * This is called only on ->probe() stage where a device is either in
920 	 * known state defined by BIOS or most likely powered off. Due to this
921 	 * we have to deassert reset line to be sure that ->probe() will
922 	 * recognize the device.
923 	 */
924 	if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE))
925 		lpss_deassert_reset(pdata);
926 
927 #ifdef CONFIG_PM
928 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX_ONCE)
929 		acpi_lpss_save_ctx(dev, pdata);
930 #endif
931 
932 	return 0;
933 }
934 
935 static void acpi_lpss_dismiss(struct device *dev)
936 {
937 	acpi_dev_suspend(dev, false);
938 }
939 
940 /* IOSF SB for LPSS island */
941 #define LPSS_IOSF_UNIT_LPIOEP		0xA0
942 #define LPSS_IOSF_UNIT_LPIO1		0xAB
943 #define LPSS_IOSF_UNIT_LPIO2		0xAC
944 
945 #define LPSS_IOSF_PMCSR			0x84
946 #define LPSS_PMCSR_D0			0
947 #define LPSS_PMCSR_D3hot		3
948 #define LPSS_PMCSR_Dx_MASK		GENMASK(1, 0)
949 
950 #define LPSS_IOSF_GPIODEF0		0x154
951 #define LPSS_GPIODEF0_DMA1_D3		BIT(2)
952 #define LPSS_GPIODEF0_DMA2_D3		BIT(3)
953 #define LPSS_GPIODEF0_DMA_D3_MASK	GENMASK(3, 2)
954 #define LPSS_GPIODEF0_DMA_LLP		BIT(13)
955 
956 static DEFINE_MUTEX(lpss_iosf_mutex);
957 static bool lpss_iosf_d3_entered = true;
958 
959 static void lpss_iosf_enter_d3_state(void)
960 {
961 	u32 value1 = 0;
962 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
963 	u32 value2 = LPSS_PMCSR_D3hot;
964 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
965 	/*
966 	 * PMC provides an information about actual status of the LPSS devices.
967 	 * Here we read the values related to LPSS power island, i.e. LPSS
968 	 * devices, excluding both LPSS DMA controllers, along with SCC domain.
969 	 */
970 	u32 func_dis, d3_sts_0, pmc_status;
971 	int ret;
972 
973 	ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
974 	if (ret)
975 		return;
976 
977 	mutex_lock(&lpss_iosf_mutex);
978 
979 	ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
980 	if (ret)
981 		goto exit;
982 
983 	/*
984 	 * Get the status of entire LPSS power island per device basis.
985 	 * Shutdown both LPSS DMA controllers if and only if all other devices
986 	 * are already in D3hot.
987 	 */
988 	pmc_status = (~(d3_sts_0 | func_dis)) & pmc_atom_d3_mask;
989 	if (pmc_status)
990 		goto exit;
991 
992 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
993 			LPSS_IOSF_PMCSR, value2, mask2);
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_LPIOEP, MBI_CR_WRITE,
999 			LPSS_IOSF_GPIODEF0, value1, mask1);
1000 
1001 	lpss_iosf_d3_entered = true;
1002 
1003 exit:
1004 	mutex_unlock(&lpss_iosf_mutex);
1005 }
1006 
1007 static void lpss_iosf_exit_d3_state(void)
1008 {
1009 	u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3 |
1010 		     LPSS_GPIODEF0_DMA_LLP;
1011 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
1012 	u32 value2 = LPSS_PMCSR_D0;
1013 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
1014 
1015 	mutex_lock(&lpss_iosf_mutex);
1016 
1017 	if (!lpss_iosf_d3_entered)
1018 		goto exit;
1019 
1020 	lpss_iosf_d3_entered = false;
1021 
1022 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
1023 			LPSS_IOSF_GPIODEF0, value1, mask1);
1024 
1025 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
1026 			LPSS_IOSF_PMCSR, value2, mask2);
1027 
1028 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
1029 			LPSS_IOSF_PMCSR, value2, mask2);
1030 
1031 exit:
1032 	mutex_unlock(&lpss_iosf_mutex);
1033 }
1034 
1035 static int acpi_lpss_suspend(struct device *dev, bool wakeup)
1036 {
1037 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1038 	int ret;
1039 
1040 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
1041 		acpi_lpss_save_ctx(dev, pdata);
1042 
1043 	ret = acpi_dev_suspend(dev, wakeup);
1044 
1045 	/*
1046 	 * This call must be last in the sequence, otherwise PMC will return
1047 	 * wrong status for devices being about to be powered off. See
1048 	 * lpss_iosf_enter_d3_state() for further information.
1049 	 */
1050 	if (acpi_target_system_state() == ACPI_STATE_S0 &&
1051 	    lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1052 		lpss_iosf_enter_d3_state();
1053 
1054 	return ret;
1055 }
1056 
1057 static int acpi_lpss_resume(struct device *dev)
1058 {
1059 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1060 	int ret;
1061 
1062 	/*
1063 	 * This call is kept first to be in symmetry with
1064 	 * acpi_lpss_runtime_suspend() one.
1065 	 */
1066 	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
1067 		lpss_iosf_exit_d3_state();
1068 
1069 	ret = acpi_dev_resume(dev);
1070 	if (ret)
1071 		return ret;
1072 
1073 	acpi_lpss_d3_to_d0_delay(pdata);
1074 
1075 	if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE))
1076 		acpi_lpss_restore_ctx(dev, pdata);
1077 
1078 	return 0;
1079 }
1080 
1081 #ifdef CONFIG_PM_SLEEP
1082 static int acpi_lpss_do_suspend_late(struct device *dev)
1083 {
1084 	int ret;
1085 
1086 	if (dev_pm_skip_suspend(dev))
1087 		return 0;
1088 
1089 	ret = pm_generic_suspend_late(dev);
1090 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1091 }
1092 
1093 static int acpi_lpss_suspend_late(struct device *dev)
1094 {
1095 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1096 
1097 	if (pdata->dev_desc->resume_from_noirq)
1098 		return 0;
1099 
1100 	return acpi_lpss_do_suspend_late(dev);
1101 }
1102 
1103 static int acpi_lpss_suspend_noirq(struct device *dev)
1104 {
1105 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1106 	int ret;
1107 
1108 	if (pdata->dev_desc->resume_from_noirq) {
1109 		/*
1110 		 * The driver's ->suspend_late callback will be invoked by
1111 		 * acpi_lpss_do_suspend_late(), with the assumption that the
1112 		 * driver really wanted to run that code in ->suspend_noirq, but
1113 		 * it could not run after acpi_dev_suspend() and the driver
1114 		 * expected the latter to be called in the "late" phase.
1115 		 */
1116 		ret = acpi_lpss_do_suspend_late(dev);
1117 		if (ret)
1118 			return ret;
1119 	}
1120 
1121 	return acpi_subsys_suspend_noirq(dev);
1122 }
1123 
1124 static int acpi_lpss_do_resume_early(struct device *dev)
1125 {
1126 	int ret = acpi_lpss_resume(dev);
1127 
1128 	return ret ? ret : pm_generic_resume_early(dev);
1129 }
1130 
1131 static int acpi_lpss_resume_early(struct device *dev)
1132 {
1133 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1134 
1135 	if (pdata->dev_desc->resume_from_noirq)
1136 		return 0;
1137 
1138 	if (dev_pm_skip_resume(dev))
1139 		return 0;
1140 
1141 	return acpi_lpss_do_resume_early(dev);
1142 }
1143 
1144 static int acpi_lpss_resume_noirq(struct device *dev)
1145 {
1146 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1147 	int ret;
1148 
1149 	/* Follow acpi_subsys_resume_noirq(). */
1150 	if (dev_pm_skip_resume(dev))
1151 		return 0;
1152 
1153 	ret = pm_generic_resume_noirq(dev);
1154 	if (ret)
1155 		return ret;
1156 
1157 	if (!pdata->dev_desc->resume_from_noirq)
1158 		return 0;
1159 
1160 	/*
1161 	 * The driver's ->resume_early callback will be invoked by
1162 	 * acpi_lpss_do_resume_early(), with the assumption that the driver
1163 	 * really wanted to run that code in ->resume_noirq, but it could not
1164 	 * run before acpi_dev_resume() and the driver expected the latter to be
1165 	 * called in the "early" phase.
1166 	 */
1167 	return acpi_lpss_do_resume_early(dev);
1168 }
1169 
1170 static int acpi_lpss_do_restore_early(struct device *dev)
1171 {
1172 	int ret = acpi_lpss_resume(dev);
1173 
1174 	return ret ? ret : pm_generic_restore_early(dev);
1175 }
1176 
1177 static int acpi_lpss_restore_early(struct device *dev)
1178 {
1179 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1180 
1181 	if (pdata->dev_desc->resume_from_noirq)
1182 		return 0;
1183 
1184 	return acpi_lpss_do_restore_early(dev);
1185 }
1186 
1187 static int acpi_lpss_restore_noirq(struct device *dev)
1188 {
1189 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1190 	int ret;
1191 
1192 	ret = pm_generic_restore_noirq(dev);
1193 	if (ret)
1194 		return ret;
1195 
1196 	if (!pdata->dev_desc->resume_from_noirq)
1197 		return 0;
1198 
1199 	/* This is analogous to what happens in acpi_lpss_resume_noirq(). */
1200 	return acpi_lpss_do_restore_early(dev);
1201 }
1202 
1203 static int acpi_lpss_do_poweroff_late(struct device *dev)
1204 {
1205 	int ret = pm_generic_poweroff_late(dev);
1206 
1207 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
1208 }
1209 
1210 static int acpi_lpss_poweroff_late(struct device *dev)
1211 {
1212 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1213 
1214 	if (dev_pm_skip_suspend(dev))
1215 		return 0;
1216 
1217 	if (pdata->dev_desc->resume_from_noirq)
1218 		return 0;
1219 
1220 	return acpi_lpss_do_poweroff_late(dev);
1221 }
1222 
1223 static int acpi_lpss_poweroff_noirq(struct device *dev)
1224 {
1225 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1226 
1227 	if (dev_pm_skip_suspend(dev))
1228 		return 0;
1229 
1230 	if (pdata->dev_desc->resume_from_noirq) {
1231 		/* This is analogous to the acpi_lpss_suspend_noirq() case. */
1232 		int ret = acpi_lpss_do_poweroff_late(dev);
1233 
1234 		if (ret)
1235 			return ret;
1236 	}
1237 
1238 	return pm_generic_poweroff_noirq(dev);
1239 }
1240 #endif /* CONFIG_PM_SLEEP */
1241 
1242 static int acpi_lpss_runtime_suspend(struct device *dev)
1243 {
1244 	int ret = pm_generic_runtime_suspend(dev);
1245 
1246 	return ret ? ret : acpi_lpss_suspend(dev, true);
1247 }
1248 
1249 static int acpi_lpss_runtime_resume(struct device *dev)
1250 {
1251 	int ret = acpi_lpss_resume(dev);
1252 
1253 	return ret ? ret : pm_generic_runtime_resume(dev);
1254 }
1255 #endif /* CONFIG_PM */
1256 
1257 static struct dev_pm_domain acpi_lpss_pm_domain = {
1258 #ifdef CONFIG_PM
1259 	.activate = acpi_lpss_activate,
1260 	.dismiss = acpi_lpss_dismiss,
1261 #endif
1262 	.ops = {
1263 #ifdef CONFIG_PM
1264 #ifdef CONFIG_PM_SLEEP
1265 		.prepare = acpi_subsys_prepare,
1266 		.complete = acpi_subsys_complete,
1267 		.suspend = acpi_subsys_suspend,
1268 		.suspend_late = acpi_lpss_suspend_late,
1269 		.suspend_noirq = acpi_lpss_suspend_noirq,
1270 		.resume_noirq = acpi_lpss_resume_noirq,
1271 		.resume_early = acpi_lpss_resume_early,
1272 		.freeze = acpi_subsys_freeze,
1273 		.poweroff = acpi_subsys_poweroff,
1274 		.poweroff_late = acpi_lpss_poweroff_late,
1275 		.poweroff_noirq = acpi_lpss_poweroff_noirq,
1276 		.restore_noirq = acpi_lpss_restore_noirq,
1277 		.restore_early = acpi_lpss_restore_early,
1278 #endif
1279 		.runtime_suspend = acpi_lpss_runtime_suspend,
1280 		.runtime_resume = acpi_lpss_runtime_resume,
1281 #endif
1282 	},
1283 };
1284 
1285 static int acpi_lpss_platform_notify(struct notifier_block *nb,
1286 				     unsigned long action, void *data)
1287 {
1288 	struct platform_device *pdev = to_platform_device(data);
1289 	struct lpss_private_data *pdata;
1290 	struct acpi_device *adev;
1291 	const struct acpi_device_id *id;
1292 
1293 	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
1294 	if (!id || !id->driver_data)
1295 		return 0;
1296 
1297 	adev = ACPI_COMPANION(&pdev->dev);
1298 	if (!adev)
1299 		return 0;
1300 
1301 	pdata = acpi_driver_data(adev);
1302 	if (!pdata)
1303 		return 0;
1304 
1305 	if (pdata->mmio_base &&
1306 	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
1307 		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
1308 		return 0;
1309 	}
1310 
1311 	switch (action) {
1312 	case BUS_NOTIFY_BIND_DRIVER:
1313 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1314 		break;
1315 	case BUS_NOTIFY_DRIVER_NOT_BOUND:
1316 	case BUS_NOTIFY_UNBOUND_DRIVER:
1317 		dev_pm_domain_set(&pdev->dev, NULL);
1318 		break;
1319 	case BUS_NOTIFY_ADD_DEVICE:
1320 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1321 		if (pdata->dev_desc->flags & LPSS_LTR)
1322 			return sysfs_create_group(&pdev->dev.kobj,
1323 						  &lpss_attr_group);
1324 		break;
1325 	case BUS_NOTIFY_DEL_DEVICE:
1326 		if (pdata->dev_desc->flags & LPSS_LTR)
1327 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
1328 		dev_pm_domain_set(&pdev->dev, NULL);
1329 		break;
1330 	default:
1331 		break;
1332 	}
1333 
1334 	return 0;
1335 }
1336 
1337 static struct notifier_block acpi_lpss_nb = {
1338 	.notifier_call = acpi_lpss_platform_notify,
1339 };
1340 
1341 static void acpi_lpss_bind(struct device *dev)
1342 {
1343 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1344 
1345 	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
1346 		return;
1347 
1348 	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
1349 		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
1350 	else
1351 		dev_err(dev, "MMIO size insufficient to access LTR\n");
1352 }
1353 
1354 static void acpi_lpss_unbind(struct device *dev)
1355 {
1356 	dev->power.set_latency_tolerance = NULL;
1357 }
1358 
1359 static struct acpi_scan_handler lpss_handler = {
1360 	.ids = acpi_lpss_device_ids,
1361 	.attach = acpi_lpss_create_device,
1362 	.bind = acpi_lpss_bind,
1363 	.unbind = acpi_lpss_unbind,
1364 };
1365 
1366 void __init acpi_lpss_init(void)
1367 {
1368 	const struct x86_cpu_id *id;
1369 	int ret;
1370 
1371 	ret = lpss_atom_clk_init();
1372 	if (ret)
1373 		return;
1374 
1375 	id = x86_match_cpu(lpss_cpu_ids);
1376 	if (id)
1377 		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
1378 
1379 	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
1380 	acpi_scan_add_handler(&lpss_handler);
1381 }
1382 
1383 #else
1384 
1385 static struct acpi_scan_handler lpss_handler = {
1386 	.ids = acpi_lpss_device_ids,
1387 };
1388 
1389 void __init acpi_lpss_init(void)
1390 {
1391 	acpi_scan_add_handler(&lpss_handler);
1392 }
1393 
1394 #endif /* CONFIG_X86_INTEL_LPSS */
1395