xref: /openbmc/linux/drivers/acpi/acpi_lpss.c (revision ff6defa6)
1 /*
2  * ACPI support for Intel Lynxpoint LPSS.
3  *
4  * Copyright (C) 2013, 2014, 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/clk.h>
15 #include <linux/clkdev.h>
16 #include <linux/clk-provider.h>
17 #include <linux/err.h>
18 #include <linux/io.h>
19 #include <linux/platform_device.h>
20 #include <linux/platform_data/clk-lpss.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/delay.h>
23 
24 #include "internal.h"
25 
26 ACPI_MODULE_NAME("acpi_lpss");
27 
28 #ifdef CONFIG_X86_INTEL_LPSS
29 
30 #define LPSS_ADDR(desc) ((unsigned long)&desc)
31 
32 #define LPSS_CLK_SIZE	0x04
33 #define LPSS_LTR_SIZE	0x18
34 
35 /* Offsets relative to LPSS_PRIVATE_OFFSET */
36 #define LPSS_CLK_DIVIDER_DEF_MASK	(BIT(1) | BIT(16))
37 #define LPSS_RESETS			0x04
38 #define LPSS_RESETS_RESET_FUNC		BIT(0)
39 #define LPSS_RESETS_RESET_APB		BIT(1)
40 #define LPSS_GENERAL			0x08
41 #define LPSS_GENERAL_LTR_MODE_SW	BIT(2)
42 #define LPSS_GENERAL_UART_RTS_OVRD	BIT(3)
43 #define LPSS_SW_LTR			0x10
44 #define LPSS_AUTO_LTR			0x14
45 #define LPSS_LTR_SNOOP_REQ		BIT(15)
46 #define LPSS_LTR_SNOOP_MASK		0x0000FFFF
47 #define LPSS_LTR_SNOOP_LAT_1US		0x800
48 #define LPSS_LTR_SNOOP_LAT_32US		0xC00
49 #define LPSS_LTR_SNOOP_LAT_SHIFT	5
50 #define LPSS_LTR_SNOOP_LAT_CUTOFF	3000
51 #define LPSS_LTR_MAX_VAL		0x3FF
52 #define LPSS_TX_INT			0x20
53 #define LPSS_TX_INT_MASK		BIT(1)
54 
55 #define LPSS_PRV_REG_COUNT		9
56 
57 /* LPSS Flags */
58 #define LPSS_CLK			BIT(0)
59 #define LPSS_CLK_GATE			BIT(1)
60 #define LPSS_CLK_DIVIDER		BIT(2)
61 #define LPSS_LTR			BIT(3)
62 #define LPSS_SAVE_CTX			BIT(4)
63 #define LPSS_DEV_PROXY			BIT(5)
64 #define LPSS_PROXY_REQ			BIT(6)
65 
66 struct lpss_private_data;
67 
68 struct lpss_device_desc {
69 	unsigned int flags;
70 	unsigned int prv_offset;
71 	size_t prv_size_override;
72 	void (*setup)(struct lpss_private_data *pdata);
73 };
74 
75 static struct device *proxy_device;
76 
77 static struct lpss_device_desc lpss_dma_desc = {
78 	.flags = LPSS_CLK | LPSS_PROXY_REQ,
79 };
80 
81 struct lpss_private_data {
82 	void __iomem *mmio_base;
83 	resource_size_t mmio_size;
84 	unsigned int fixed_clk_rate;
85 	struct clk *clk;
86 	const struct lpss_device_desc *dev_desc;
87 	u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
88 };
89 
90 /* UART Component Parameter Register */
91 #define LPSS_UART_CPR			0xF4
92 #define LPSS_UART_CPR_AFCE		BIT(4)
93 
94 static void lpss_uart_setup(struct lpss_private_data *pdata)
95 {
96 	unsigned int offset;
97 	u32 val;
98 
99 	offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
100 	val = readl(pdata->mmio_base + offset);
101 	writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
102 
103 	val = readl(pdata->mmio_base + LPSS_UART_CPR);
104 	if (!(val & LPSS_UART_CPR_AFCE)) {
105 		offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
106 		val = readl(pdata->mmio_base + offset);
107 		val |= LPSS_GENERAL_UART_RTS_OVRD;
108 		writel(val, pdata->mmio_base + offset);
109 	}
110 }
111 
112 static void byt_i2c_setup(struct lpss_private_data *pdata)
113 {
114 	unsigned int offset;
115 	u32 val;
116 
117 	offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
118 	val = readl(pdata->mmio_base + offset);
119 	val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
120 	writel(val, pdata->mmio_base + offset);
121 
122 	if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
123 		pdata->fixed_clk_rate = 133000000;
124 }
125 
126 static struct lpss_device_desc lpt_dev_desc = {
127 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
128 	.prv_offset = 0x800,
129 };
130 
131 static struct lpss_device_desc lpt_i2c_dev_desc = {
132 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR,
133 	.prv_offset = 0x800,
134 };
135 
136 static struct lpss_device_desc lpt_uart_dev_desc = {
137 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
138 	.prv_offset = 0x800,
139 	.setup = lpss_uart_setup,
140 };
141 
142 static struct lpss_device_desc lpt_sdio_dev_desc = {
143 	.flags = LPSS_LTR,
144 	.prv_offset = 0x1000,
145 	.prv_size_override = 0x1018,
146 };
147 
148 static struct lpss_device_desc byt_pwm_dev_desc = {
149 	.flags = LPSS_SAVE_CTX,
150 };
151 
152 static struct lpss_device_desc byt_uart_dev_desc = {
153 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX |
154 		 LPSS_DEV_PROXY,
155 	.prv_offset = 0x800,
156 	.setup = lpss_uart_setup,
157 };
158 
159 static struct lpss_device_desc byt_spi_dev_desc = {
160 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX |
161 		 LPSS_DEV_PROXY,
162 	.prv_offset = 0x400,
163 };
164 
165 static struct lpss_device_desc byt_sdio_dev_desc = {
166 	.flags = LPSS_CLK | LPSS_DEV_PROXY,
167 };
168 
169 static struct lpss_device_desc byt_i2c_dev_desc = {
170 	.flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_DEV_PROXY,
171 	.prv_offset = 0x800,
172 	.setup = byt_i2c_setup,
173 };
174 
175 #else
176 
177 #define LPSS_ADDR(desc) (0UL)
178 
179 #endif /* CONFIG_X86_INTEL_LPSS */
180 
181 static const struct acpi_device_id acpi_lpss_device_ids[] = {
182 	/* Generic LPSS devices */
183 	{ "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
184 
185 	/* Lynxpoint LPSS devices */
186 	{ "INT33C0", LPSS_ADDR(lpt_dev_desc) },
187 	{ "INT33C1", LPSS_ADDR(lpt_dev_desc) },
188 	{ "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
189 	{ "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
190 	{ "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
191 	{ "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
192 	{ "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
193 	{ "INT33C7", },
194 
195 	/* BayTrail LPSS devices */
196 	{ "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
197 	{ "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
198 	{ "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
199 	{ "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
200 	{ "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
201 	{ "INT33B2", },
202 	{ "INT33FC", },
203 
204 	/* Braswell LPSS devices */
205 	{ "80862288", LPSS_ADDR(byt_pwm_dev_desc) },
206 	{ "8086228A", LPSS_ADDR(byt_uart_dev_desc) },
207 	{ "8086228E", LPSS_ADDR(byt_spi_dev_desc) },
208 	{ "808622C1", LPSS_ADDR(byt_i2c_dev_desc) },
209 
210 	{ "INT3430", LPSS_ADDR(lpt_dev_desc) },
211 	{ "INT3431", LPSS_ADDR(lpt_dev_desc) },
212 	{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
213 	{ "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
214 	{ "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
215 	{ "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
216 	{ "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
217 	{ "INT3437", },
218 
219 	/* Wildcat Point LPSS devices */
220 	{ "INT3438", LPSS_ADDR(lpt_dev_desc) },
221 
222 	{ }
223 };
224 
225 #ifdef CONFIG_X86_INTEL_LPSS
226 
227 static int is_memory(struct acpi_resource *res, void *not_used)
228 {
229 	struct resource r;
230 	return !acpi_dev_resource_memory(res, &r);
231 }
232 
233 /* LPSS main clock device. */
234 static struct platform_device *lpss_clk_dev;
235 
236 static inline void lpt_register_clock_device(void)
237 {
238 	lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
239 }
240 
241 static int register_device_clock(struct acpi_device *adev,
242 				 struct lpss_private_data *pdata)
243 {
244 	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
245 	const char *devname = dev_name(&adev->dev);
246 	struct clk *clk = ERR_PTR(-ENODEV);
247 	struct lpss_clk_data *clk_data;
248 	const char *parent, *clk_name;
249 	void __iomem *prv_base;
250 
251 	if (!lpss_clk_dev)
252 		lpt_register_clock_device();
253 
254 	clk_data = platform_get_drvdata(lpss_clk_dev);
255 	if (!clk_data)
256 		return -ENODEV;
257 	clk = clk_data->clk;
258 
259 	if (!pdata->mmio_base
260 	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
261 		return -ENODATA;
262 
263 	parent = clk_data->name;
264 	prv_base = pdata->mmio_base + dev_desc->prv_offset;
265 
266 	if (pdata->fixed_clk_rate) {
267 		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
268 					      pdata->fixed_clk_rate);
269 		goto out;
270 	}
271 
272 	if (dev_desc->flags & LPSS_CLK_GATE) {
273 		clk = clk_register_gate(NULL, devname, parent, 0,
274 					prv_base, 0, 0, NULL);
275 		parent = devname;
276 	}
277 
278 	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
279 		/* Prevent division by zero */
280 		if (!readl(prv_base))
281 			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
282 
283 		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
284 		if (!clk_name)
285 			return -ENOMEM;
286 		clk = clk_register_fractional_divider(NULL, clk_name, parent,
287 						      0, prv_base,
288 						      1, 15, 16, 15, 0, NULL);
289 		parent = clk_name;
290 
291 		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
292 		if (!clk_name) {
293 			kfree(parent);
294 			return -ENOMEM;
295 		}
296 		clk = clk_register_gate(NULL, clk_name, parent,
297 					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
298 					prv_base, 31, 0, NULL);
299 		kfree(parent);
300 		kfree(clk_name);
301 	}
302 out:
303 	if (IS_ERR(clk))
304 		return PTR_ERR(clk);
305 
306 	pdata->clk = clk;
307 	clk_register_clkdev(clk, NULL, devname);
308 	return 0;
309 }
310 
311 static int acpi_lpss_create_device(struct acpi_device *adev,
312 				   const struct acpi_device_id *id)
313 {
314 	struct lpss_device_desc *dev_desc;
315 	struct lpss_private_data *pdata;
316 	struct resource_list_entry *rentry;
317 	struct list_head resource_list;
318 	struct platform_device *pdev;
319 	int ret;
320 
321 	dev_desc = (struct lpss_device_desc *)id->driver_data;
322 	if (!dev_desc) {
323 		pdev = acpi_create_platform_device(adev);
324 		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
325 	}
326 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
327 	if (!pdata)
328 		return -ENOMEM;
329 
330 	INIT_LIST_HEAD(&resource_list);
331 	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
332 	if (ret < 0)
333 		goto err_out;
334 
335 	list_for_each_entry(rentry, &resource_list, node)
336 		if (resource_type(&rentry->res) == IORESOURCE_MEM) {
337 			if (dev_desc->prv_size_override)
338 				pdata->mmio_size = dev_desc->prv_size_override;
339 			else
340 				pdata->mmio_size = resource_size(&rentry->res);
341 			pdata->mmio_base = ioremap(rentry->res.start,
342 						   pdata->mmio_size);
343 			break;
344 		}
345 
346 	acpi_dev_free_resource_list(&resource_list);
347 
348 	pdata->dev_desc = dev_desc;
349 
350 	if (dev_desc->setup)
351 		dev_desc->setup(pdata);
352 
353 	if (dev_desc->flags & LPSS_CLK) {
354 		ret = register_device_clock(adev, pdata);
355 		if (ret) {
356 			/* Skip the device, but continue the namespace scan. */
357 			ret = 0;
358 			goto err_out;
359 		}
360 	}
361 
362 	/*
363 	 * This works around a known issue in ACPI tables where LPSS devices
364 	 * have _PS0 and _PS3 without _PSC (and no power resources), so
365 	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
366 	 */
367 	ret = acpi_device_fix_up_power(adev);
368 	if (ret) {
369 		/* Skip the device, but continue the namespace scan. */
370 		ret = 0;
371 		goto err_out;
372 	}
373 
374 	adev->driver_data = pdata;
375 	pdev = acpi_create_platform_device(adev);
376 	if (!IS_ERR_OR_NULL(pdev)) {
377 		if (!proxy_device && dev_desc->flags & LPSS_DEV_PROXY)
378 			proxy_device = &pdev->dev;
379 		return 1;
380 	}
381 
382 	ret = PTR_ERR(pdev);
383 	adev->driver_data = NULL;
384 
385  err_out:
386 	kfree(pdata);
387 	return ret;
388 }
389 
390 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
391 {
392 	return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
393 }
394 
395 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
396 			     unsigned int reg)
397 {
398 	writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
399 }
400 
401 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
402 {
403 	struct acpi_device *adev;
404 	struct lpss_private_data *pdata;
405 	unsigned long flags;
406 	int ret;
407 
408 	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
409 	if (WARN_ON(ret))
410 		return ret;
411 
412 	spin_lock_irqsave(&dev->power.lock, flags);
413 	if (pm_runtime_suspended(dev)) {
414 		ret = -EAGAIN;
415 		goto out;
416 	}
417 	pdata = acpi_driver_data(adev);
418 	if (WARN_ON(!pdata || !pdata->mmio_base)) {
419 		ret = -ENODEV;
420 		goto out;
421 	}
422 	*val = __lpss_reg_read(pdata, reg);
423 
424  out:
425 	spin_unlock_irqrestore(&dev->power.lock, flags);
426 	return ret;
427 }
428 
429 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
430 			     char *buf)
431 {
432 	u32 ltr_value = 0;
433 	unsigned int reg;
434 	int ret;
435 
436 	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
437 	ret = lpss_reg_read(dev, reg, &ltr_value);
438 	if (ret)
439 		return ret;
440 
441 	return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
442 }
443 
444 static ssize_t lpss_ltr_mode_show(struct device *dev,
445 				  struct device_attribute *attr, char *buf)
446 {
447 	u32 ltr_mode = 0;
448 	char *outstr;
449 	int ret;
450 
451 	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
452 	if (ret)
453 		return ret;
454 
455 	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
456 	return sprintf(buf, "%s\n", outstr);
457 }
458 
459 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
460 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
461 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
462 
463 static struct attribute *lpss_attrs[] = {
464 	&dev_attr_auto_ltr.attr,
465 	&dev_attr_sw_ltr.attr,
466 	&dev_attr_ltr_mode.attr,
467 	NULL,
468 };
469 
470 static struct attribute_group lpss_attr_group = {
471 	.attrs = lpss_attrs,
472 	.name = "lpss_ltr",
473 };
474 
475 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
476 {
477 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
478 	u32 ltr_mode, ltr_val;
479 
480 	ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
481 	if (val < 0) {
482 		if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
483 			ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
484 			__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
485 		}
486 		return;
487 	}
488 	ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
489 	if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
490 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
491 		val = LPSS_LTR_MAX_VAL;
492 	} else if (val > LPSS_LTR_MAX_VAL) {
493 		ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
494 		val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
495 	} else {
496 		ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
497 	}
498 	ltr_val |= val;
499 	__lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
500 	if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
501 		ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
502 		__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
503 	}
504 }
505 
506 #ifdef CONFIG_PM
507 /**
508  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
509  * @dev: LPSS device
510  * @pdata: pointer to the private data of the LPSS device
511  *
512  * Most LPSS devices have private registers which may loose their context when
513  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
514  * prv_reg_ctx array.
515  */
516 static void acpi_lpss_save_ctx(struct device *dev,
517 			       struct lpss_private_data *pdata)
518 {
519 	unsigned int i;
520 
521 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
522 		unsigned long offset = i * sizeof(u32);
523 
524 		pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
525 		dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
526 			pdata->prv_reg_ctx[i], offset);
527 	}
528 }
529 
530 /**
531  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
532  * @dev: LPSS device
533  * @pdata: pointer to the private data of the LPSS device
534  *
535  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
536  */
537 static void acpi_lpss_restore_ctx(struct device *dev,
538 				  struct lpss_private_data *pdata)
539 {
540 	unsigned int i;
541 
542 	/*
543 	 * The following delay is needed or the subsequent write operations may
544 	 * fail. The LPSS devices are actually PCI devices and the PCI spec
545 	 * expects 10ms delay before the device can be accessed after D3 to D0
546 	 * transition.
547 	 */
548 	msleep(10);
549 
550 	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
551 		unsigned long offset = i * sizeof(u32);
552 
553 		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
554 		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
555 			pdata->prv_reg_ctx[i], offset);
556 	}
557 }
558 
559 #ifdef CONFIG_PM_SLEEP
560 static int acpi_lpss_suspend_late(struct device *dev)
561 {
562 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
563 	int ret;
564 
565 	ret = pm_generic_suspend_late(dev);
566 	if (ret)
567 		return ret;
568 
569 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
570 		acpi_lpss_save_ctx(dev, pdata);
571 
572 	return acpi_dev_suspend_late(dev);
573 }
574 
575 static int acpi_lpss_resume_early(struct device *dev)
576 {
577 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
578 	int ret;
579 
580 	ret = acpi_dev_resume_early(dev);
581 	if (ret)
582 		return ret;
583 
584 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
585 		acpi_lpss_restore_ctx(dev, pdata);
586 
587 	return pm_generic_resume_early(dev);
588 }
589 #endif /* CONFIG_PM_SLEEP */
590 
591 static int acpi_lpss_runtime_suspend(struct device *dev)
592 {
593 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
594 	int ret;
595 
596 	ret = pm_generic_runtime_suspend(dev);
597 	if (ret)
598 		return ret;
599 
600 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
601 		acpi_lpss_save_ctx(dev, pdata);
602 
603 	ret = acpi_dev_runtime_suspend(dev);
604 	if (ret)
605 		return ret;
606 
607 	if (pdata->dev_desc->flags & LPSS_PROXY_REQ && proxy_device)
608 		return pm_runtime_put_sync_suspend(proxy_device);
609 
610 	return 0;
611 }
612 
613 static int acpi_lpss_runtime_resume(struct device *dev)
614 {
615 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
616 	int ret;
617 
618 	if (pdata->dev_desc->flags & LPSS_PROXY_REQ && proxy_device) {
619 		ret = pm_runtime_get_sync(proxy_device);
620 		if (ret)
621 			return ret;
622 	}
623 
624 	ret = acpi_dev_runtime_resume(dev);
625 	if (ret)
626 		return ret;
627 
628 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
629 		acpi_lpss_restore_ctx(dev, pdata);
630 
631 	return pm_generic_runtime_resume(dev);
632 }
633 #endif /* CONFIG_PM */
634 
635 static struct dev_pm_domain acpi_lpss_pm_domain = {
636 	.ops = {
637 #ifdef CONFIG_PM
638 #ifdef CONFIG_PM_SLEEP
639 		.prepare = acpi_subsys_prepare,
640 		.complete = acpi_subsys_complete,
641 		.suspend = acpi_subsys_suspend,
642 		.suspend_late = acpi_lpss_suspend_late,
643 		.resume_early = acpi_lpss_resume_early,
644 		.freeze = acpi_subsys_freeze,
645 		.poweroff = acpi_subsys_suspend,
646 		.poweroff_late = acpi_lpss_suspend_late,
647 		.restore_early = acpi_lpss_resume_early,
648 #endif
649 		.runtime_suspend = acpi_lpss_runtime_suspend,
650 		.runtime_resume = acpi_lpss_runtime_resume,
651 #endif
652 	},
653 };
654 
655 static int acpi_lpss_platform_notify(struct notifier_block *nb,
656 				     unsigned long action, void *data)
657 {
658 	struct platform_device *pdev = to_platform_device(data);
659 	struct lpss_private_data *pdata;
660 	struct acpi_device *adev;
661 	const struct acpi_device_id *id;
662 
663 	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
664 	if (!id || !id->driver_data)
665 		return 0;
666 
667 	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
668 		return 0;
669 
670 	pdata = acpi_driver_data(adev);
671 	if (!pdata)
672 		return 0;
673 
674 	if (pdata->mmio_base &&
675 	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
676 		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
677 		return 0;
678 	}
679 
680 	switch (action) {
681 	case BUS_NOTIFY_ADD_DEVICE:
682 		pdev->dev.pm_domain = &acpi_lpss_pm_domain;
683 		if (pdata->dev_desc->flags & LPSS_LTR)
684 			return sysfs_create_group(&pdev->dev.kobj,
685 						  &lpss_attr_group);
686 		break;
687 	case BUS_NOTIFY_DEL_DEVICE:
688 		if (pdata->dev_desc->flags & LPSS_LTR)
689 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
690 		pdev->dev.pm_domain = NULL;
691 		break;
692 	default:
693 		break;
694 	}
695 
696 	return 0;
697 }
698 
699 static struct notifier_block acpi_lpss_nb = {
700 	.notifier_call = acpi_lpss_platform_notify,
701 };
702 
703 static void acpi_lpss_bind(struct device *dev)
704 {
705 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
706 
707 	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
708 		return;
709 
710 	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
711 		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
712 	else
713 		dev_err(dev, "MMIO size insufficient to access LTR\n");
714 }
715 
716 static void acpi_lpss_unbind(struct device *dev)
717 {
718 	dev->power.set_latency_tolerance = NULL;
719 }
720 
721 static struct acpi_scan_handler lpss_handler = {
722 	.ids = acpi_lpss_device_ids,
723 	.attach = acpi_lpss_create_device,
724 	.bind = acpi_lpss_bind,
725 	.unbind = acpi_lpss_unbind,
726 };
727 
728 void __init acpi_lpss_init(void)
729 {
730 	if (!lpt_clk_init()) {
731 		bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
732 		acpi_scan_add_handler(&lpss_handler);
733 	}
734 }
735 
736 #else
737 
738 static struct acpi_scan_handler lpss_handler = {
739 	.ids = acpi_lpss_device_ids,
740 };
741 
742 void __init acpi_lpss_init(void)
743 {
744 	acpi_scan_add_handler(&lpss_handler);
745 }
746 
747 #endif /* CONFIG_X86_INTEL_LPSS */
748