xref: /openbmc/linux/drivers/acpi/acpi_lpss.c (revision a9a08845)
1 /*
2  * ACPI support for Intel Lynxpoint LPSS.
3  *
4  * Copyright (C) 2013, Intel Corporation
5  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
6  *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/acpi.h>
14 #include <linux/clkdev.h>
15 #include <linux/clk-provider.h>
16 #include <linux/err.h>
17 #include <linux/io.h>
18 #include <linux/mutex.h>
19 #include <linux/platform_device.h>
20 #include <linux/platform_data/clk-lpss.h>
21 #include <linux/platform_data/x86/pmc_atom.h>
22 #include <linux/pm_domain.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/pwm.h>
25 #include <linux/delay.h>
26 
27 #include "internal.h"
28 
29 ACPI_MODULE_NAME("acpi_lpss");
30 
31 #ifdef CONFIG_X86_INTEL_LPSS
32 
33 #include <asm/cpu_device_id.h>
34 #include <asm/intel-family.h>
35 #include <asm/iosf_mbi.h>
36 
37 #define LPSS_ADDR(desc) ((unsigned long)&desc)
38 
39 #define LPSS_CLK_SIZE	0x04
40 #define LPSS_LTR_SIZE	0x18
41 
42 /* Offsets relative to LPSS_PRIVATE_OFFSET */
43 #define LPSS_CLK_DIVIDER_DEF_MASK	(BIT(1) | BIT(16))
44 #define LPSS_RESETS			0x04
45 #define LPSS_RESETS_RESET_FUNC		BIT(0)
46 #define LPSS_RESETS_RESET_APB		BIT(1)
47 #define LPSS_GENERAL			0x08
48 #define LPSS_GENERAL_LTR_MODE_SW	BIT(2)
49 #define LPSS_GENERAL_UART_RTS_OVRD	BIT(3)
50 #define LPSS_SW_LTR			0x10
51 #define LPSS_AUTO_LTR			0x14
52 #define LPSS_LTR_SNOOP_REQ		BIT(15)
53 #define LPSS_LTR_SNOOP_MASK		0x0000FFFF
54 #define LPSS_LTR_SNOOP_LAT_1US		0x800
55 #define LPSS_LTR_SNOOP_LAT_32US		0xC00
56 #define LPSS_LTR_SNOOP_LAT_SHIFT	5
57 #define LPSS_LTR_SNOOP_LAT_CUTOFF	3000
58 #define LPSS_LTR_MAX_VAL		0x3FF
59 #define LPSS_TX_INT			0x20
60 #define LPSS_TX_INT_MASK		BIT(1)
61 
62 #define LPSS_PRV_REG_COUNT		9
63 
64 /* LPSS Flags */
65 #define LPSS_CLK			BIT(0)
66 #define LPSS_CLK_GATE			BIT(1)
67 #define LPSS_CLK_DIVIDER		BIT(2)
68 #define LPSS_LTR			BIT(3)
69 #define LPSS_SAVE_CTX			BIT(4)
70 #define LPSS_NO_D3_DELAY		BIT(5)
71 
72 struct lpss_private_data;
73 
74 struct lpss_device_desc {
75 	unsigned int flags;
76 	const char *clk_con_id;
77 	unsigned int prv_offset;
78 	size_t prv_size_override;
79 	struct property_entry *properties;
80 	void (*setup)(struct lpss_private_data *pdata);
81 };
82 
83 static const struct lpss_device_desc lpss_dma_desc = {
84 	.flags = LPSS_CLK,
85 };
86 
87 struct lpss_private_data {
88 	struct acpi_device *adev;
89 	void __iomem *mmio_base;
90 	resource_size_t mmio_size;
91 	unsigned int fixed_clk_rate;
92 	struct clk *clk;
93 	const struct lpss_device_desc *dev_desc;
94 	u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
95 };
96 
97 /* LPSS run time quirks */
98 static unsigned int lpss_quirks;
99 
100 /*
101  * LPSS_QUIRK_ALWAYS_POWER_ON: override power state for LPSS DMA device.
102  *
103  * The LPSS DMA controller has neither _PS0 nor _PS3 method. Moreover
104  * it can be powered off automatically whenever the last LPSS device goes down.
105  * In case of no power any access to the DMA controller will hang the system.
106  * The behaviour is reproduced on some HP laptops based on Intel BayTrail as
107  * well as on ASuS T100TA transformer.
108  *
109  * This quirk overrides power state of entire LPSS island to keep DMA powered
110  * on whenever we have at least one other device in use.
111  */
112 #define LPSS_QUIRK_ALWAYS_POWER_ON	BIT(0)
113 
114 /* UART Component Parameter Register */
115 #define LPSS_UART_CPR			0xF4
116 #define LPSS_UART_CPR_AFCE		BIT(4)
117 
118 static void lpss_uart_setup(struct lpss_private_data *pdata)
119 {
120 	unsigned int offset;
121 	u32 val;
122 
123 	offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
124 	val = readl(pdata->mmio_base + offset);
125 	writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
126 
127 	val = readl(pdata->mmio_base + LPSS_UART_CPR);
128 	if (!(val & LPSS_UART_CPR_AFCE)) {
129 		offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
130 		val = readl(pdata->mmio_base + offset);
131 		val |= LPSS_GENERAL_UART_RTS_OVRD;
132 		writel(val, pdata->mmio_base + offset);
133 	}
134 }
135 
136 static void lpss_deassert_reset(struct lpss_private_data *pdata)
137 {
138 	unsigned int offset;
139 	u32 val;
140 
141 	offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
142 	val = readl(pdata->mmio_base + offset);
143 	val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
144 	writel(val, pdata->mmio_base + offset);
145 }
146 
147 /*
148  * BYT PWM used for backlight control by the i915 driver on systems without
149  * the Crystal Cove PMIC.
150  */
151 static struct pwm_lookup byt_pwm_lookup[] = {
152 	PWM_LOOKUP_WITH_MODULE("80860F09:00", 0, "0000:00:02.0",
153 			       "pwm_backlight", 0, PWM_POLARITY_NORMAL,
154 			       "pwm-lpss-platform"),
155 };
156 
157 static void byt_pwm_setup(struct lpss_private_data *pdata)
158 {
159 	struct acpi_device *adev = pdata->adev;
160 
161 	/* Only call pwm_add_table for the first PWM controller */
162 	if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
163 		return;
164 
165 	if (!acpi_dev_present("INT33FD", NULL, -1))
166 		pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup));
167 }
168 
169 #define LPSS_I2C_ENABLE			0x6c
170 
171 static void byt_i2c_setup(struct lpss_private_data *pdata)
172 {
173 	lpss_deassert_reset(pdata);
174 
175 	if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
176 		pdata->fixed_clk_rate = 133000000;
177 
178 	writel(0, pdata->mmio_base + LPSS_I2C_ENABLE);
179 }
180 
181 /* BSW PWM used for backlight control by the i915 driver */
182 static struct pwm_lookup bsw_pwm_lookup[] = {
183 	PWM_LOOKUP_WITH_MODULE("80862288:00", 0, "0000:00:02.0",
184 			       "pwm_backlight", 0, PWM_POLARITY_NORMAL,
185 			       "pwm-lpss-platform"),
186 };
187 
188 static void bsw_pwm_setup(struct lpss_private_data *pdata)
189 {
190 	struct acpi_device *adev = pdata->adev;
191 
192 	/* Only call pwm_add_table for the first PWM controller */
193 	if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
194 		return;
195 
196 	pwm_add_table(bsw_pwm_lookup, ARRAY_SIZE(bsw_pwm_lookup));
197 }
198 
199 static const struct lpss_device_desc lpt_dev_desc = {
200 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
201 	.prv_offset = 0x800,
202 };
203 
204 static const struct lpss_device_desc lpt_i2c_dev_desc = {
205 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR,
206 	.prv_offset = 0x800,
207 };
208 
209 static struct property_entry uart_properties[] = {
210 	PROPERTY_ENTRY_U32("reg-io-width", 4),
211 	PROPERTY_ENTRY_U32("reg-shift", 2),
212 	PROPERTY_ENTRY_BOOL("snps,uart-16550-compatible"),
213 	{ },
214 };
215 
216 static const struct lpss_device_desc lpt_uart_dev_desc = {
217 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
218 	.clk_con_id = "baudclk",
219 	.prv_offset = 0x800,
220 	.setup = lpss_uart_setup,
221 	.properties = uart_properties,
222 };
223 
224 static const struct lpss_device_desc lpt_sdio_dev_desc = {
225 	.flags = LPSS_LTR,
226 	.prv_offset = 0x1000,
227 	.prv_size_override = 0x1018,
228 };
229 
230 static const struct lpss_device_desc byt_pwm_dev_desc = {
231 	.flags = LPSS_SAVE_CTX,
232 	.setup = byt_pwm_setup,
233 };
234 
235 static const struct lpss_device_desc bsw_pwm_dev_desc = {
236 	.flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
237 	.setup = bsw_pwm_setup,
238 };
239 
240 static const struct lpss_device_desc byt_uart_dev_desc = {
241 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
242 	.clk_con_id = "baudclk",
243 	.prv_offset = 0x800,
244 	.setup = lpss_uart_setup,
245 	.properties = uart_properties,
246 };
247 
248 static const struct lpss_device_desc bsw_uart_dev_desc = {
249 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
250 			| LPSS_NO_D3_DELAY,
251 	.clk_con_id = "baudclk",
252 	.prv_offset = 0x800,
253 	.setup = lpss_uart_setup,
254 	.properties = uart_properties,
255 };
256 
257 static const struct lpss_device_desc byt_spi_dev_desc = {
258 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
259 	.prv_offset = 0x400,
260 };
261 
262 static const struct lpss_device_desc byt_sdio_dev_desc = {
263 	.flags = LPSS_CLK,
264 };
265 
266 static const struct lpss_device_desc byt_i2c_dev_desc = {
267 	.flags = LPSS_CLK | LPSS_SAVE_CTX,
268 	.prv_offset = 0x800,
269 	.setup = byt_i2c_setup,
270 };
271 
272 static const struct lpss_device_desc bsw_i2c_dev_desc = {
273 	.flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
274 	.prv_offset = 0x800,
275 	.setup = byt_i2c_setup,
276 };
277 
278 static const struct lpss_device_desc bsw_spi_dev_desc = {
279 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
280 			| LPSS_NO_D3_DELAY,
281 	.prv_offset = 0x400,
282 	.setup = lpss_deassert_reset,
283 };
284 
285 #define ICPU(model)	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }
286 
287 static const struct x86_cpu_id lpss_cpu_ids[] = {
288 	ICPU(INTEL_FAM6_ATOM_SILVERMONT1),	/* Valleyview, Bay Trail */
289 	ICPU(INTEL_FAM6_ATOM_AIRMONT),	/* Braswell, Cherry Trail */
290 	{}
291 };
292 
293 #else
294 
295 #define LPSS_ADDR(desc) (0UL)
296 
297 #endif /* CONFIG_X86_INTEL_LPSS */
298 
299 static const struct acpi_device_id acpi_lpss_device_ids[] = {
300 	/* Generic LPSS devices */
301 	{ "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
302 
303 	/* Lynxpoint LPSS devices */
304 	{ "INT33C0", LPSS_ADDR(lpt_dev_desc) },
305 	{ "INT33C1", LPSS_ADDR(lpt_dev_desc) },
306 	{ "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
307 	{ "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
308 	{ "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
309 	{ "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
310 	{ "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
311 	{ "INT33C7", },
312 
313 	/* BayTrail LPSS devices */
314 	{ "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
315 	{ "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
316 	{ "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
317 	{ "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
318 	{ "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
319 	{ "INT33B2", },
320 	{ "INT33FC", },
321 
322 	/* Braswell LPSS devices */
323 	{ "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
324 	{ "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
325 	{ "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
326 	{ "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
327 
328 	/* Broadwell LPSS devices */
329 	{ "INT3430", LPSS_ADDR(lpt_dev_desc) },
330 	{ "INT3431", LPSS_ADDR(lpt_dev_desc) },
331 	{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
332 	{ "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
333 	{ "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
334 	{ "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
335 	{ "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
336 	{ "INT3437", },
337 
338 	/* Wildcat Point LPSS devices */
339 	{ "INT3438", LPSS_ADDR(lpt_dev_desc) },
340 
341 	{ }
342 };
343 
344 #ifdef CONFIG_X86_INTEL_LPSS
345 
346 static int is_memory(struct acpi_resource *res, void *not_used)
347 {
348 	struct resource r;
349 	return !acpi_dev_resource_memory(res, &r);
350 }
351 
352 /* LPSS main clock device. */
353 static struct platform_device *lpss_clk_dev;
354 
355 static inline void lpt_register_clock_device(void)
356 {
357 	lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
358 }
359 
360 static int register_device_clock(struct acpi_device *adev,
361 				 struct lpss_private_data *pdata)
362 {
363 	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
364 	const char *devname = dev_name(&adev->dev);
365 	struct clk *clk;
366 	struct lpss_clk_data *clk_data;
367 	const char *parent, *clk_name;
368 	void __iomem *prv_base;
369 
370 	if (!lpss_clk_dev)
371 		lpt_register_clock_device();
372 
373 	clk_data = platform_get_drvdata(lpss_clk_dev);
374 	if (!clk_data)
375 		return -ENODEV;
376 	clk = clk_data->clk;
377 
378 	if (!pdata->mmio_base
379 	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
380 		return -ENODATA;
381 
382 	parent = clk_data->name;
383 	prv_base = pdata->mmio_base + dev_desc->prv_offset;
384 
385 	if (pdata->fixed_clk_rate) {
386 		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
387 					      pdata->fixed_clk_rate);
388 		goto out;
389 	}
390 
391 	if (dev_desc->flags & LPSS_CLK_GATE) {
392 		clk = clk_register_gate(NULL, devname, parent, 0,
393 					prv_base, 0, 0, NULL);
394 		parent = devname;
395 	}
396 
397 	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
398 		/* Prevent division by zero */
399 		if (!readl(prv_base))
400 			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
401 
402 		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
403 		if (!clk_name)
404 			return -ENOMEM;
405 		clk = clk_register_fractional_divider(NULL, clk_name, parent,
406 						      0, prv_base,
407 						      1, 15, 16, 15, 0, NULL);
408 		parent = clk_name;
409 
410 		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
411 		if (!clk_name) {
412 			kfree(parent);
413 			return -ENOMEM;
414 		}
415 		clk = clk_register_gate(NULL, clk_name, parent,
416 					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
417 					prv_base, 31, 0, NULL);
418 		kfree(parent);
419 		kfree(clk_name);
420 	}
421 out:
422 	if (IS_ERR(clk))
423 		return PTR_ERR(clk);
424 
425 	pdata->clk = clk;
426 	clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
427 	return 0;
428 }
429 
430 struct lpss_device_links {
431 	const char *supplier_hid;
432 	const char *supplier_uid;
433 	const char *consumer_hid;
434 	const char *consumer_uid;
435 	u32 flags;
436 };
437 
438 /*
439  * The _DEP method is used to identify dependencies but instead of creating
440  * device links for every handle in _DEP, only links in the following list are
441  * created. That is necessary because, in the general case, _DEP can refer to
442  * devices that might not have drivers, or that are on different buses, or where
443  * the supplier is not enumerated until after the consumer is probed.
444  */
445 static const struct lpss_device_links lpss_device_links[] = {
446 	{"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME},
447 };
448 
449 static bool hid_uid_match(const char *hid1, const char *uid1,
450 			  const char *hid2, const char *uid2)
451 {
452 	return !strcmp(hid1, hid2) && uid1 && uid2 && !strcmp(uid1, uid2);
453 }
454 
455 static bool acpi_lpss_is_supplier(struct acpi_device *adev,
456 				  const struct lpss_device_links *link)
457 {
458 	return hid_uid_match(acpi_device_hid(adev), acpi_device_uid(adev),
459 			     link->supplier_hid, link->supplier_uid);
460 }
461 
462 static bool acpi_lpss_is_consumer(struct acpi_device *adev,
463 				  const struct lpss_device_links *link)
464 {
465 	return hid_uid_match(acpi_device_hid(adev), acpi_device_uid(adev),
466 			     link->consumer_hid, link->consumer_uid);
467 }
468 
469 struct hid_uid {
470 	const char *hid;
471 	const char *uid;
472 };
473 
474 static int match_hid_uid(struct device *dev, void *data)
475 {
476 	struct acpi_device *adev = ACPI_COMPANION(dev);
477 	struct hid_uid *id = data;
478 
479 	if (!adev)
480 		return 0;
481 
482 	return hid_uid_match(acpi_device_hid(adev), acpi_device_uid(adev),
483 			     id->hid, id->uid);
484 }
485 
486 static struct device *acpi_lpss_find_device(const char *hid, const char *uid)
487 {
488 	struct hid_uid data = {
489 		.hid = hid,
490 		.uid = uid,
491 	};
492 
493 	return bus_find_device(&platform_bus_type, NULL, &data, match_hid_uid);
494 }
495 
496 static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle)
497 {
498 	struct acpi_handle_list dep_devices;
499 	acpi_status status;
500 	int i;
501 
502 	if (!acpi_has_method(adev->handle, "_DEP"))
503 		return false;
504 
505 	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
506 					 &dep_devices);
507 	if (ACPI_FAILURE(status)) {
508 		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
509 		return false;
510 	}
511 
512 	for (i = 0; i < dep_devices.count; i++) {
513 		if (dep_devices.handles[i] == handle)
514 			return true;
515 	}
516 
517 	return false;
518 }
519 
520 static void acpi_lpss_link_consumer(struct device *dev1,
521 				    const struct lpss_device_links *link)
522 {
523 	struct device *dev2;
524 
525 	dev2 = acpi_lpss_find_device(link->consumer_hid, link->consumer_uid);
526 	if (!dev2)
527 		return;
528 
529 	if (acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1)))
530 		device_link_add(dev2, dev1, link->flags);
531 
532 	put_device(dev2);
533 }
534 
535 static void acpi_lpss_link_supplier(struct device *dev1,
536 				    const struct lpss_device_links *link)
537 {
538 	struct device *dev2;
539 
540 	dev2 = acpi_lpss_find_device(link->supplier_hid, link->supplier_uid);
541 	if (!dev2)
542 		return;
543 
544 	if (acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2)))
545 		device_link_add(dev1, dev2, link->flags);
546 
547 	put_device(dev2);
548 }
549 
550 static void acpi_lpss_create_device_links(struct acpi_device *adev,
551 					  struct platform_device *pdev)
552 {
553 	int i;
554 
555 	for (i = 0; i < ARRAY_SIZE(lpss_device_links); i++) {
556 		const struct lpss_device_links *link = &lpss_device_links[i];
557 
558 		if (acpi_lpss_is_supplier(adev, link))
559 			acpi_lpss_link_consumer(&pdev->dev, link);
560 
561 		if (acpi_lpss_is_consumer(adev, link))
562 			acpi_lpss_link_supplier(&pdev->dev, link);
563 	}
564 }
565 
566 static int acpi_lpss_create_device(struct acpi_device *adev,
567 				   const struct acpi_device_id *id)
568 {
569 	const struct lpss_device_desc *dev_desc;
570 	struct lpss_private_data *pdata;
571 	struct resource_entry *rentry;
572 	struct list_head resource_list;
573 	struct platform_device *pdev;
574 	int ret;
575 
576 	dev_desc = (const struct lpss_device_desc *)id->driver_data;
577 	if (!dev_desc) {
578 		pdev = acpi_create_platform_device(adev, NULL);
579 		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
580 	}
581 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
582 	if (!pdata)
583 		return -ENOMEM;
584 
585 	INIT_LIST_HEAD(&resource_list);
586 	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
587 	if (ret < 0)
588 		goto err_out;
589 
590 	list_for_each_entry(rentry, &resource_list, node)
591 		if (resource_type(rentry->res) == IORESOURCE_MEM) {
592 			if (dev_desc->prv_size_override)
593 				pdata->mmio_size = dev_desc->prv_size_override;
594 			else
595 				pdata->mmio_size = resource_size(rentry->res);
596 			pdata->mmio_base = ioremap(rentry->res->start,
597 						   pdata->mmio_size);
598 			break;
599 		}
600 
601 	acpi_dev_free_resource_list(&resource_list);
602 
603 	if (!pdata->mmio_base) {
604 		/* Avoid acpi_bus_attach() instantiating a pdev for this dev. */
605 		adev->pnp.type.platform_id = 0;
606 		/* Skip the device, but continue the namespace scan. */
607 		ret = 0;
608 		goto err_out;
609 	}
610 
611 	pdata->adev = adev;
612 	pdata->dev_desc = dev_desc;
613 
614 	if (dev_desc->setup)
615 		dev_desc->setup(pdata);
616 
617 	if (dev_desc->flags & LPSS_CLK) {
618 		ret = register_device_clock(adev, pdata);
619 		if (ret) {
620 			/* Skip the device, but continue the namespace scan. */
621 			ret = 0;
622 			goto err_out;
623 		}
624 	}
625 
626 	/*
627 	 * This works around a known issue in ACPI tables where LPSS devices
628 	 * have _PS0 and _PS3 without _PSC (and no power resources), so
629 	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
630 	 */
631 	ret = acpi_device_fix_up_power(adev);
632 	if (ret) {
633 		/* Skip the device, but continue the namespace scan. */
634 		ret = 0;
635 		goto err_out;
636 	}
637 
638 	adev->driver_data = pdata;
639 	pdev = acpi_create_platform_device(adev, dev_desc->properties);
640 	if (!IS_ERR_OR_NULL(pdev)) {
641 		acpi_lpss_create_device_links(adev, pdev);
642 		return 1;
643 	}
644 
645 	ret = PTR_ERR(pdev);
646 	adev->driver_data = NULL;
647 
648  err_out:
649 	kfree(pdata);
650 	return ret;
651 }
652 
653 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
654 {
655 	return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
656 }
657 
658 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
659 			     unsigned int reg)
660 {
661 	writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
662 }
663 
664 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
665 {
666 	struct acpi_device *adev;
667 	struct lpss_private_data *pdata;
668 	unsigned long flags;
669 	int ret;
670 
671 	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
672 	if (WARN_ON(ret))
673 		return ret;
674 
675 	spin_lock_irqsave(&dev->power.lock, flags);
676 	if (pm_runtime_suspended(dev)) {
677 		ret = -EAGAIN;
678 		goto out;
679 	}
680 	pdata = acpi_driver_data(adev);
681 	if (WARN_ON(!pdata || !pdata->mmio_base)) {
682 		ret = -ENODEV;
683 		goto out;
684 	}
685 	*val = __lpss_reg_read(pdata, reg);
686 
687  out:
688 	spin_unlock_irqrestore(&dev->power.lock, flags);
689 	return ret;
690 }
691 
692 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
693 			     char *buf)
694 {
695 	u32 ltr_value = 0;
696 	unsigned int reg;
697 	int ret;
698 
699 	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
700 	ret = lpss_reg_read(dev, reg, &ltr_value);
701 	if (ret)
702 		return ret;
703 
704 	return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
705 }
706 
707 static ssize_t lpss_ltr_mode_show(struct device *dev,
708 				  struct device_attribute *attr, char *buf)
709 {
710 	u32 ltr_mode = 0;
711 	char *outstr;
712 	int ret;
713 
714 	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
715 	if (ret)
716 		return ret;
717 
718 	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
719 	return sprintf(buf, "%s\n", outstr);
720 }
721 
722 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
723 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
724 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
725 
726 static struct attribute *lpss_attrs[] = {
727 	&dev_attr_auto_ltr.attr,
728 	&dev_attr_sw_ltr.attr,
729 	&dev_attr_ltr_mode.attr,
730 	NULL,
731 };
732 
733 static const struct attribute_group lpss_attr_group = {
734 	.attrs = lpss_attrs,
735 	.name = "lpss_ltr",
736 };
737 
738 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
739 {
740 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
741 	u32 ltr_mode, ltr_val;
742 
743 	ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
744 	if (val < 0) {
745 		if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
746 			ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
747 			__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
748 		}
749 		return;
750 	}
751 	ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
752 	if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
753 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
754 		val = LPSS_LTR_MAX_VAL;
755 	} else if (val > LPSS_LTR_MAX_VAL) {
756 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
757 		val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
758 	} else {
759 		ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
760 	}
761 	ltr_val |= val;
762 	__lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
763 	if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
764 		ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
765 		__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
766 	}
767 }
768 
769 #ifdef CONFIG_PM
770 /**
771  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
772  * @dev: LPSS device
773  * @pdata: pointer to the private data of the LPSS device
774  *
775  * Most LPSS devices have private registers which may loose their context when
776  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
777  * prv_reg_ctx array.
778  */
779 static void acpi_lpss_save_ctx(struct device *dev,
780 			       struct lpss_private_data *pdata)
781 {
782 	unsigned int i;
783 
784 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
785 		unsigned long offset = i * sizeof(u32);
786 
787 		pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
788 		dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
789 			pdata->prv_reg_ctx[i], offset);
790 	}
791 }
792 
793 /**
794  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
795  * @dev: LPSS device
796  * @pdata: pointer to the private data of the LPSS device
797  *
798  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
799  */
800 static void acpi_lpss_restore_ctx(struct device *dev,
801 				  struct lpss_private_data *pdata)
802 {
803 	unsigned int i;
804 
805 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
806 		unsigned long offset = i * sizeof(u32);
807 
808 		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
809 		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
810 			pdata->prv_reg_ctx[i], offset);
811 	}
812 }
813 
814 static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
815 {
816 	/*
817 	 * The following delay is needed or the subsequent write operations may
818 	 * fail. The LPSS devices are actually PCI devices and the PCI spec
819 	 * expects 10ms delay before the device can be accessed after D3 to D0
820 	 * transition. However some platforms like BSW does not need this delay.
821 	 */
822 	unsigned int delay = 10;	/* default 10ms delay */
823 
824 	if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
825 		delay = 0;
826 
827 	msleep(delay);
828 }
829 
830 static int acpi_lpss_activate(struct device *dev)
831 {
832 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
833 	int ret;
834 
835 	ret = acpi_dev_resume(dev);
836 	if (ret)
837 		return ret;
838 
839 	acpi_lpss_d3_to_d0_delay(pdata);
840 
841 	/*
842 	 * This is called only on ->probe() stage where a device is either in
843 	 * known state defined by BIOS or most likely powered off. Due to this
844 	 * we have to deassert reset line to be sure that ->probe() will
845 	 * recognize the device.
846 	 */
847 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
848 		lpss_deassert_reset(pdata);
849 
850 	return 0;
851 }
852 
853 static void acpi_lpss_dismiss(struct device *dev)
854 {
855 	acpi_dev_suspend(dev, false);
856 }
857 
858 /* IOSF SB for LPSS island */
859 #define LPSS_IOSF_UNIT_LPIOEP		0xA0
860 #define LPSS_IOSF_UNIT_LPIO1		0xAB
861 #define LPSS_IOSF_UNIT_LPIO2		0xAC
862 
863 #define LPSS_IOSF_PMCSR			0x84
864 #define LPSS_PMCSR_D0			0
865 #define LPSS_PMCSR_D3hot		3
866 #define LPSS_PMCSR_Dx_MASK		GENMASK(1, 0)
867 
868 #define LPSS_IOSF_GPIODEF0		0x154
869 #define LPSS_GPIODEF0_DMA1_D3		BIT(2)
870 #define LPSS_GPIODEF0_DMA2_D3		BIT(3)
871 #define LPSS_GPIODEF0_DMA_D3_MASK	GENMASK(3, 2)
872 #define LPSS_GPIODEF0_DMA_LLP		BIT(13)
873 
874 static DEFINE_MUTEX(lpss_iosf_mutex);
875 
876 static void lpss_iosf_enter_d3_state(void)
877 {
878 	u32 value1 = 0;
879 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
880 	u32 value2 = LPSS_PMCSR_D3hot;
881 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
882 	/*
883 	 * PMC provides an information about actual status of the LPSS devices.
884 	 * Here we read the values related to LPSS power island, i.e. LPSS
885 	 * devices, excluding both LPSS DMA controllers, along with SCC domain.
886 	 */
887 	u32 func_dis, d3_sts_0, pmc_status, pmc_mask = 0xfe000ffe;
888 	int ret;
889 
890 	ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
891 	if (ret)
892 		return;
893 
894 	mutex_lock(&lpss_iosf_mutex);
895 
896 	ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
897 	if (ret)
898 		goto exit;
899 
900 	/*
901 	 * Get the status of entire LPSS power island per device basis.
902 	 * Shutdown both LPSS DMA controllers if and only if all other devices
903 	 * are already in D3hot.
904 	 */
905 	pmc_status = (~(d3_sts_0 | func_dis)) & pmc_mask;
906 	if (pmc_status)
907 		goto exit;
908 
909 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
910 			LPSS_IOSF_PMCSR, value2, mask2);
911 
912 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
913 			LPSS_IOSF_PMCSR, value2, mask2);
914 
915 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
916 			LPSS_IOSF_GPIODEF0, value1, mask1);
917 exit:
918 	mutex_unlock(&lpss_iosf_mutex);
919 }
920 
921 static void lpss_iosf_exit_d3_state(void)
922 {
923 	u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3 |
924 		     LPSS_GPIODEF0_DMA_LLP;
925 	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
926 	u32 value2 = LPSS_PMCSR_D0;
927 	u32 mask2 = LPSS_PMCSR_Dx_MASK;
928 
929 	mutex_lock(&lpss_iosf_mutex);
930 
931 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
932 			LPSS_IOSF_GPIODEF0, value1, mask1);
933 
934 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
935 			LPSS_IOSF_PMCSR, value2, mask2);
936 
937 	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
938 			LPSS_IOSF_PMCSR, value2, mask2);
939 
940 	mutex_unlock(&lpss_iosf_mutex);
941 }
942 
943 static int acpi_lpss_suspend(struct device *dev, bool wakeup)
944 {
945 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
946 	int ret;
947 
948 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
949 		acpi_lpss_save_ctx(dev, pdata);
950 
951 	ret = acpi_dev_suspend(dev, wakeup);
952 
953 	/*
954 	 * This call must be last in the sequence, otherwise PMC will return
955 	 * wrong status for devices being about to be powered off. See
956 	 * lpss_iosf_enter_d3_state() for further information.
957 	 */
958 	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
959 		lpss_iosf_enter_d3_state();
960 
961 	return ret;
962 }
963 
964 static int acpi_lpss_resume(struct device *dev)
965 {
966 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
967 	int ret;
968 
969 	/*
970 	 * This call is kept first to be in symmetry with
971 	 * acpi_lpss_runtime_suspend() one.
972 	 */
973 	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
974 		lpss_iosf_exit_d3_state();
975 
976 	ret = acpi_dev_resume(dev);
977 	if (ret)
978 		return ret;
979 
980 	acpi_lpss_d3_to_d0_delay(pdata);
981 
982 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
983 		acpi_lpss_restore_ctx(dev, pdata);
984 
985 	return 0;
986 }
987 
988 #ifdef CONFIG_PM_SLEEP
989 static int acpi_lpss_suspend_late(struct device *dev)
990 {
991 	int ret;
992 
993 	if (dev_pm_smart_suspend_and_suspended(dev))
994 		return 0;
995 
996 	ret = pm_generic_suspend_late(dev);
997 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
998 }
999 
1000 static int acpi_lpss_resume_early(struct device *dev)
1001 {
1002 	int ret = acpi_lpss_resume(dev);
1003 
1004 	return ret ? ret : pm_generic_resume_early(dev);
1005 }
1006 #endif /* CONFIG_PM_SLEEP */
1007 
1008 static int acpi_lpss_runtime_suspend(struct device *dev)
1009 {
1010 	int ret = pm_generic_runtime_suspend(dev);
1011 
1012 	return ret ? ret : acpi_lpss_suspend(dev, true);
1013 }
1014 
1015 static int acpi_lpss_runtime_resume(struct device *dev)
1016 {
1017 	int ret = acpi_lpss_resume(dev);
1018 
1019 	return ret ? ret : pm_generic_runtime_resume(dev);
1020 }
1021 #endif /* CONFIG_PM */
1022 
1023 static struct dev_pm_domain acpi_lpss_pm_domain = {
1024 #ifdef CONFIG_PM
1025 	.activate = acpi_lpss_activate,
1026 	.dismiss = acpi_lpss_dismiss,
1027 #endif
1028 	.ops = {
1029 #ifdef CONFIG_PM
1030 #ifdef CONFIG_PM_SLEEP
1031 		.prepare = acpi_subsys_prepare,
1032 		.complete = acpi_subsys_complete,
1033 		.suspend = acpi_subsys_suspend,
1034 		.suspend_late = acpi_lpss_suspend_late,
1035 		.suspend_noirq = acpi_subsys_suspend_noirq,
1036 		.resume_noirq = acpi_subsys_resume_noirq,
1037 		.resume_early = acpi_lpss_resume_early,
1038 		.freeze = acpi_subsys_freeze,
1039 		.freeze_late = acpi_subsys_freeze_late,
1040 		.freeze_noirq = acpi_subsys_freeze_noirq,
1041 		.thaw_noirq = acpi_subsys_thaw_noirq,
1042 		.poweroff = acpi_subsys_suspend,
1043 		.poweroff_late = acpi_lpss_suspend_late,
1044 		.poweroff_noirq = acpi_subsys_suspend_noirq,
1045 		.restore_noirq = acpi_subsys_resume_noirq,
1046 		.restore_early = acpi_lpss_resume_early,
1047 #endif
1048 		.runtime_suspend = acpi_lpss_runtime_suspend,
1049 		.runtime_resume = acpi_lpss_runtime_resume,
1050 #endif
1051 	},
1052 };
1053 
1054 static int acpi_lpss_platform_notify(struct notifier_block *nb,
1055 				     unsigned long action, void *data)
1056 {
1057 	struct platform_device *pdev = to_platform_device(data);
1058 	struct lpss_private_data *pdata;
1059 	struct acpi_device *adev;
1060 	const struct acpi_device_id *id;
1061 
1062 	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
1063 	if (!id || !id->driver_data)
1064 		return 0;
1065 
1066 	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
1067 		return 0;
1068 
1069 	pdata = acpi_driver_data(adev);
1070 	if (!pdata)
1071 		return 0;
1072 
1073 	if (pdata->mmio_base &&
1074 	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
1075 		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
1076 		return 0;
1077 	}
1078 
1079 	switch (action) {
1080 	case BUS_NOTIFY_BIND_DRIVER:
1081 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1082 		break;
1083 	case BUS_NOTIFY_DRIVER_NOT_BOUND:
1084 	case BUS_NOTIFY_UNBOUND_DRIVER:
1085 		dev_pm_domain_set(&pdev->dev, NULL);
1086 		break;
1087 	case BUS_NOTIFY_ADD_DEVICE:
1088 		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
1089 		if (pdata->dev_desc->flags & LPSS_LTR)
1090 			return sysfs_create_group(&pdev->dev.kobj,
1091 						  &lpss_attr_group);
1092 		break;
1093 	case BUS_NOTIFY_DEL_DEVICE:
1094 		if (pdata->dev_desc->flags & LPSS_LTR)
1095 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
1096 		dev_pm_domain_set(&pdev->dev, NULL);
1097 		break;
1098 	default:
1099 		break;
1100 	}
1101 
1102 	return 0;
1103 }
1104 
1105 static struct notifier_block acpi_lpss_nb = {
1106 	.notifier_call = acpi_lpss_platform_notify,
1107 };
1108 
1109 static void acpi_lpss_bind(struct device *dev)
1110 {
1111 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
1112 
1113 	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
1114 		return;
1115 
1116 	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
1117 		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
1118 	else
1119 		dev_err(dev, "MMIO size insufficient to access LTR\n");
1120 }
1121 
1122 static void acpi_lpss_unbind(struct device *dev)
1123 {
1124 	dev->power.set_latency_tolerance = NULL;
1125 }
1126 
1127 static struct acpi_scan_handler lpss_handler = {
1128 	.ids = acpi_lpss_device_ids,
1129 	.attach = acpi_lpss_create_device,
1130 	.bind = acpi_lpss_bind,
1131 	.unbind = acpi_lpss_unbind,
1132 };
1133 
1134 void __init acpi_lpss_init(void)
1135 {
1136 	const struct x86_cpu_id *id;
1137 	int ret;
1138 
1139 	ret = lpt_clk_init();
1140 	if (ret)
1141 		return;
1142 
1143 	id = x86_match_cpu(lpss_cpu_ids);
1144 	if (id)
1145 		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
1146 
1147 	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
1148 	acpi_scan_add_handler(&lpss_handler);
1149 }
1150 
1151 #else
1152 
1153 static struct acpi_scan_handler lpss_handler = {
1154 	.ids = acpi_lpss_device_ids,
1155 };
1156 
1157 void __init acpi_lpss_init(void)
1158 {
1159 	acpi_scan_add_handler(&lpss_handler);
1160 }
1161 
1162 #endif /* CONFIG_X86_INTEL_LPSS */
1163