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  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/pm_domain.h>
 22#include <linux/pm_runtime.h>
 23#include <linux/delay.h>
 24
 25#include "internal.h"
 26
 27ACPI_MODULE_NAME("acpi_lpss");
 28
 29#ifdef CONFIG_X86_INTEL_LPSS
 30
 31#include <asm/cpu_device_id.h>
 32#include <asm/intel-family.h>
 33#include <asm/iosf_mbi.h>
 34#include <asm/pmc_atom.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#define LPSS_NO_D3_DELAY		BIT(5)
 70
 71struct lpss_private_data;
 72
 73struct lpss_device_desc {
 74	unsigned int flags;
 75	const char *clk_con_id;
 76	unsigned int prv_offset;
 77	size_t prv_size_override;
 78	struct property_entry *properties;
 79	void (*setup)(struct lpss_private_data *pdata);
 80};
 81
 82static const struct lpss_device_desc lpss_dma_desc = {
 83	.flags = LPSS_CLK,
 84};
 85
 86struct lpss_private_data {
 87	void __iomem *mmio_base;
 88	resource_size_t mmio_size;
 89	unsigned int fixed_clk_rate;
 90	struct clk *clk;
 91	const struct lpss_device_desc *dev_desc;
 92	u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
 93};
 94
 95/* LPSS run time quirks */
 96static unsigned int lpss_quirks;
 97
 98/*
 99 * LPSS_QUIRK_ALWAYS_POWER_ON: override power state for LPSS DMA device.
100 *
101 * The LPSS DMA controller has neither _PS0 nor _PS3 method. Moreover
102 * it can be powered off automatically whenever the last LPSS device goes down.
103 * In case of no power any access to the DMA controller will hang the system.
104 * The behaviour is reproduced on some HP laptops based on Intel BayTrail as
105 * well as on ASuS T100TA transformer.
106 *
107 * This quirk overrides power state of entire LPSS island to keep DMA powered
108 * on whenever we have at least one other device in use.
109 */
110#define LPSS_QUIRK_ALWAYS_POWER_ON	BIT(0)
111
112/* UART Component Parameter Register */
113#define LPSS_UART_CPR			0xF4
114#define LPSS_UART_CPR_AFCE		BIT(4)
115
116static void lpss_uart_setup(struct lpss_private_data *pdata)
117{
118	unsigned int offset;
119	u32 val;
120
121	offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
122	val = readl(pdata->mmio_base + offset);
123	writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
124
125	val = readl(pdata->mmio_base + LPSS_UART_CPR);
126	if (!(val & LPSS_UART_CPR_AFCE)) {
127		offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
128		val = readl(pdata->mmio_base + offset);
129		val |= LPSS_GENERAL_UART_RTS_OVRD;
130		writel(val, pdata->mmio_base + offset);
131	}
132}
133
134static void lpss_deassert_reset(struct lpss_private_data *pdata)
135{
136	unsigned int offset;
137	u32 val;
138
139	offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
140	val = readl(pdata->mmio_base + offset);
141	val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
142	writel(val, pdata->mmio_base + offset);
143}
144
145#define LPSS_I2C_ENABLE			0x6c
146
147static void byt_i2c_setup(struct lpss_private_data *pdata)
148{
149	lpss_deassert_reset(pdata);
150
151	if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
152		pdata->fixed_clk_rate = 133000000;
153
154	writel(0, pdata->mmio_base + LPSS_I2C_ENABLE);
155}
156
157static const struct lpss_device_desc lpt_dev_desc = {
158	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
159	.prv_offset = 0x800,
160};
161
162static const struct lpss_device_desc lpt_i2c_dev_desc = {
163	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR,
164	.prv_offset = 0x800,
165};
166
167static struct property_entry uart_properties[] = {
168	PROPERTY_ENTRY_U32("reg-io-width", 4),
169	PROPERTY_ENTRY_U32("reg-shift", 2),
170	PROPERTY_ENTRY_BOOL("snps,uart-16550-compatible"),
171	{ },
172};
173
174static const struct lpss_device_desc lpt_uart_dev_desc = {
175	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
176	.clk_con_id = "baudclk",
177	.prv_offset = 0x800,
178	.setup = lpss_uart_setup,
179	.properties = uart_properties,
180};
181
182static const struct lpss_device_desc lpt_sdio_dev_desc = {
183	.flags = LPSS_LTR,
184	.prv_offset = 0x1000,
185	.prv_size_override = 0x1018,
186};
187
188static const struct lpss_device_desc byt_pwm_dev_desc = {
189	.flags = LPSS_SAVE_CTX,
190};
191
192static const struct lpss_device_desc bsw_pwm_dev_desc = {
193	.flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
194};
195
196static const struct lpss_device_desc byt_uart_dev_desc = {
197	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
198	.clk_con_id = "baudclk",
199	.prv_offset = 0x800,
200	.setup = lpss_uart_setup,
201	.properties = uart_properties,
202};
203
204static const struct lpss_device_desc bsw_uart_dev_desc = {
205	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
206			| LPSS_NO_D3_DELAY,
207	.clk_con_id = "baudclk",
208	.prv_offset = 0x800,
209	.setup = lpss_uart_setup,
210	.properties = uart_properties,
211};
212
213static const struct lpss_device_desc byt_spi_dev_desc = {
214	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
215	.prv_offset = 0x400,
216};
217
218static const struct lpss_device_desc byt_sdio_dev_desc = {
219	.flags = LPSS_CLK,
220};
221
222static const struct lpss_device_desc byt_i2c_dev_desc = {
223	.flags = LPSS_CLK | LPSS_SAVE_CTX,
224	.prv_offset = 0x800,
225	.setup = byt_i2c_setup,
226};
227
228static const struct lpss_device_desc bsw_i2c_dev_desc = {
229	.flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
230	.prv_offset = 0x800,
231	.setup = byt_i2c_setup,
232};
233
234static const struct lpss_device_desc bsw_spi_dev_desc = {
235	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
236			| LPSS_NO_D3_DELAY,
237	.prv_offset = 0x400,
238	.setup = lpss_deassert_reset,
239};
240
241#define ICPU(model)	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }
242
243static const struct x86_cpu_id lpss_cpu_ids[] = {
244	ICPU(INTEL_FAM6_ATOM_SILVERMONT1),	/* Valleyview, Bay Trail */
245	ICPU(INTEL_FAM6_ATOM_AIRMONT),	/* Braswell, Cherry Trail */
246	{}
247};
248
249#else
250
251#define LPSS_ADDR(desc) (0UL)
252
253#endif /* CONFIG_X86_INTEL_LPSS */
254
255static const struct acpi_device_id acpi_lpss_device_ids[] = {
256	/* Generic LPSS devices */
257	{ "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
258
259	/* Lynxpoint LPSS devices */
260	{ "INT33C0", LPSS_ADDR(lpt_dev_desc) },
261	{ "INT33C1", LPSS_ADDR(lpt_dev_desc) },
262	{ "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
263	{ "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
264	{ "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
265	{ "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
266	{ "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
267	{ "INT33C7", },
268
269	/* BayTrail LPSS devices */
270	{ "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
271	{ "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
272	{ "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
273	{ "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
274	{ "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
275	{ "INT33B2", },
276	{ "INT33FC", },
277
278	/* Braswell LPSS devices */
279	{ "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
280	{ "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
281	{ "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
282	{ "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
283
284	/* Broadwell LPSS devices */
285	{ "INT3430", LPSS_ADDR(lpt_dev_desc) },
286	{ "INT3431", LPSS_ADDR(lpt_dev_desc) },
287	{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
288	{ "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
289	{ "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
290	{ "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
291	{ "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
292	{ "INT3437", },
293
294	/* Wildcat Point LPSS devices */
295	{ "INT3438", LPSS_ADDR(lpt_dev_desc) },
296
297	{ }
298};
299
300#ifdef CONFIG_X86_INTEL_LPSS
301
302static int is_memory(struct acpi_resource *res, void *not_used)
303{
304	struct resource r;
305	return !acpi_dev_resource_memory(res, &r);
306}
307
308/* LPSS main clock device. */
309static struct platform_device *lpss_clk_dev;
310
311static inline void lpt_register_clock_device(void)
312{
313	lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
314}
315
316static int register_device_clock(struct acpi_device *adev,
317				 struct lpss_private_data *pdata)
318{
319	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
320	const char *devname = dev_name(&adev->dev);
321	struct clk *clk = ERR_PTR(-ENODEV);
322	struct lpss_clk_data *clk_data;
323	const char *parent, *clk_name;
324	void __iomem *prv_base;
325
326	if (!lpss_clk_dev)
327		lpt_register_clock_device();
328
329	clk_data = platform_get_drvdata(lpss_clk_dev);
330	if (!clk_data)
331		return -ENODEV;
332	clk = clk_data->clk;
333
334	if (!pdata->mmio_base
335	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
336		return -ENODATA;
337
338	parent = clk_data->name;
339	prv_base = pdata->mmio_base + dev_desc->prv_offset;
340
341	if (pdata->fixed_clk_rate) {
342		clk = clk_register_fixed_rate(NULL, devname, parent, 0,
343					      pdata->fixed_clk_rate);
344		goto out;
345	}
346
347	if (dev_desc->flags & LPSS_CLK_GATE) {
348		clk = clk_register_gate(NULL, devname, parent, 0,
349					prv_base, 0, 0, NULL);
350		parent = devname;
351	}
352
353	if (dev_desc->flags & LPSS_CLK_DIVIDER) {
354		/* Prevent division by zero */
355		if (!readl(prv_base))
356			writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
357
358		clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
359		if (!clk_name)
360			return -ENOMEM;
361		clk = clk_register_fractional_divider(NULL, clk_name, parent,
362						      0, prv_base,
363						      1, 15, 16, 15, 0, NULL);
364		parent = clk_name;
365
366		clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
367		if (!clk_name) {
368			kfree(parent);
369			return -ENOMEM;
370		}
371		clk = clk_register_gate(NULL, clk_name, parent,
372					CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
373					prv_base, 31, 0, NULL);
374		kfree(parent);
375		kfree(clk_name);
376	}
377out:
378	if (IS_ERR(clk))
379		return PTR_ERR(clk);
380
381	pdata->clk = clk;
382	clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
383	return 0;
384}
385
386static int acpi_lpss_create_device(struct acpi_device *adev,
387				   const struct acpi_device_id *id)
388{
389	const struct lpss_device_desc *dev_desc;
390	struct lpss_private_data *pdata;
391	struct resource_entry *rentry;
392	struct list_head resource_list;
393	struct platform_device *pdev;
394	int ret;
395
396	dev_desc = (const struct lpss_device_desc *)id->driver_data;
397	if (!dev_desc) {
398		pdev = acpi_create_platform_device(adev, NULL);
399		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
400	}
401	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
402	if (!pdata)
403		return -ENOMEM;
404
405	INIT_LIST_HEAD(&resource_list);
406	ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
407	if (ret < 0)
408		goto err_out;
409
410	list_for_each_entry(rentry, &resource_list, node)
411		if (resource_type(rentry->res) == IORESOURCE_MEM) {
412			if (dev_desc->prv_size_override)
413				pdata->mmio_size = dev_desc->prv_size_override;
414			else
415				pdata->mmio_size = resource_size(rentry->res);
416			pdata->mmio_base = ioremap(rentry->res->start,
417						   pdata->mmio_size);
418			break;
419		}
420
421	acpi_dev_free_resource_list(&resource_list);
422
423	if (!pdata->mmio_base) {
424		ret = -ENOMEM;
425		goto err_out;
426	}
427
428	pdata->dev_desc = dev_desc;
429
430	if (dev_desc->setup)
431		dev_desc->setup(pdata);
432
433	if (dev_desc->flags & LPSS_CLK) {
434		ret = register_device_clock(adev, pdata);
435		if (ret) {
436			/* Skip the device, but continue the namespace scan. */
437			ret = 0;
438			goto err_out;
439		}
440	}
441
442	/*
443	 * This works around a known issue in ACPI tables where LPSS devices
444	 * have _PS0 and _PS3 without _PSC (and no power resources), so
445	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
446	 */
447	ret = acpi_device_fix_up_power(adev);
448	if (ret) {
449		/* Skip the device, but continue the namespace scan. */
450		ret = 0;
451		goto err_out;
452	}
453
454	adev->driver_data = pdata;
455	pdev = acpi_create_platform_device(adev, dev_desc->properties);
456	if (!IS_ERR_OR_NULL(pdev)) {
457		return 1;
458	}
459
460	ret = PTR_ERR(pdev);
461	adev->driver_data = NULL;
462
463 err_out:
464	kfree(pdata);
465	return ret;
466}
467
468static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
469{
470	return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
471}
472
473static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
474			     unsigned int reg)
475{
476	writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
477}
478
479static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
480{
481	struct acpi_device *adev;
482	struct lpss_private_data *pdata;
483	unsigned long flags;
484	int ret;
485
486	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
487	if (WARN_ON(ret))
488		return ret;
489
490	spin_lock_irqsave(&dev->power.lock, flags);
491	if (pm_runtime_suspended(dev)) {
492		ret = -EAGAIN;
493		goto out;
494	}
495	pdata = acpi_driver_data(adev);
496	if (WARN_ON(!pdata || !pdata->mmio_base)) {
497		ret = -ENODEV;
498		goto out;
499	}
500	*val = __lpss_reg_read(pdata, reg);
501
502 out:
503	spin_unlock_irqrestore(&dev->power.lock, flags);
504	return ret;
505}
506
507static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
508			     char *buf)
509{
510	u32 ltr_value = 0;
511	unsigned int reg;
512	int ret;
513
514	reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
515	ret = lpss_reg_read(dev, reg, &ltr_value);
516	if (ret)
517		return ret;
518
519	return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
520}
521
522static ssize_t lpss_ltr_mode_show(struct device *dev,
523				  struct device_attribute *attr, char *buf)
524{
525	u32 ltr_mode = 0;
526	char *outstr;
527	int ret;
528
529	ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
530	if (ret)
531		return ret;
532
533	outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
534	return sprintf(buf, "%s\n", outstr);
535}
536
537static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
538static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
539static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
540
541static struct attribute *lpss_attrs[] = {
542	&dev_attr_auto_ltr.attr,
543	&dev_attr_sw_ltr.attr,
544	&dev_attr_ltr_mode.attr,
545	NULL,
546};
547
548static struct attribute_group lpss_attr_group = {
549	.attrs = lpss_attrs,
550	.name = "lpss_ltr",
551};
552
553static void acpi_lpss_set_ltr(struct device *dev, s32 val)
554{
555	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
556	u32 ltr_mode, ltr_val;
557
558	ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
559	if (val < 0) {
560		if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
561			ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
562			__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
563		}
564		return;
565	}
566	ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
567	if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
568		ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
569		val = LPSS_LTR_MAX_VAL;
570	} else if (val > LPSS_LTR_MAX_VAL) {
571		ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
572		val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
573	} else {
574		ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
575	}
576	ltr_val |= val;
577	__lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
578	if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
579		ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
580		__lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
581	}
582}
583
584#ifdef CONFIG_PM
585/**
586 * acpi_lpss_save_ctx() - Save the private registers of LPSS device
587 * @dev: LPSS device
588 * @pdata: pointer to the private data of the LPSS device
589 *
590 * Most LPSS devices have private registers which may loose their context when
591 * the device is powered down. acpi_lpss_save_ctx() saves those registers into
592 * prv_reg_ctx array.
593 */
594static void acpi_lpss_save_ctx(struct device *dev,
595			       struct lpss_private_data *pdata)
596{
597	unsigned int i;
598
599	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
600		unsigned long offset = i * sizeof(u32);
601
602		pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
603		dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
604			pdata->prv_reg_ctx[i], offset);
605	}
606}
607
608/**
609 * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
610 * @dev: LPSS device
611 * @pdata: pointer to the private data of the LPSS device
612 *
613 * Restores the registers that were previously stored with acpi_lpss_save_ctx().
614 */
615static void acpi_lpss_restore_ctx(struct device *dev,
616				  struct lpss_private_data *pdata)
617{
618	unsigned int i;
619
620	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
621		unsigned long offset = i * sizeof(u32);
622
623		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
624		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
625			pdata->prv_reg_ctx[i], offset);
626	}
627}
628
629static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
630{
631	/*
632	 * The following delay is needed or the subsequent write operations may
633	 * fail. The LPSS devices are actually PCI devices and the PCI spec
634	 * expects 10ms delay before the device can be accessed after D3 to D0
635	 * transition. However some platforms like BSW does not need this delay.
636	 */
637	unsigned int delay = 10;	/* default 10ms delay */
638
639	if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
640		delay = 0;
641
642	msleep(delay);
643}
644
645static int acpi_lpss_activate(struct device *dev)
646{
647	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
648	int ret;
649
650	ret = acpi_dev_runtime_resume(dev);
651	if (ret)
652		return ret;
653
654	acpi_lpss_d3_to_d0_delay(pdata);
655
656	/*
657	 * This is called only on ->probe() stage where a device is either in
658	 * known state defined by BIOS or most likely powered off. Due to this
659	 * we have to deassert reset line to be sure that ->probe() will
660	 * recognize the device.
661	 */
662	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
663		lpss_deassert_reset(pdata);
664
665	return 0;
666}
667
668static void acpi_lpss_dismiss(struct device *dev)
669{
670	acpi_dev_runtime_suspend(dev);
671}
672
673#ifdef CONFIG_PM_SLEEP
674static int acpi_lpss_suspend_late(struct device *dev)
675{
676	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
677	int ret;
678
679	ret = pm_generic_suspend_late(dev);
680	if (ret)
681		return ret;
682
683	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
684		acpi_lpss_save_ctx(dev, pdata);
685
686	return acpi_dev_suspend_late(dev);
687}
688
689static int acpi_lpss_resume_early(struct device *dev)
690{
691	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
692	int ret;
693
694	ret = acpi_dev_resume_early(dev);
695	if (ret)
696		return ret;
697
698	acpi_lpss_d3_to_d0_delay(pdata);
699
700	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
701		acpi_lpss_restore_ctx(dev, pdata);
702
703	return pm_generic_resume_early(dev);
704}
705#endif /* CONFIG_PM_SLEEP */
706
707/* IOSF SB for LPSS island */
708#define LPSS_IOSF_UNIT_LPIOEP		0xA0
709#define LPSS_IOSF_UNIT_LPIO1		0xAB
710#define LPSS_IOSF_UNIT_LPIO2		0xAC
711
712#define LPSS_IOSF_PMCSR			0x84
713#define LPSS_PMCSR_D0			0
714#define LPSS_PMCSR_D3hot		3
715#define LPSS_PMCSR_Dx_MASK		GENMASK(1, 0)
716
717#define LPSS_IOSF_GPIODEF0		0x154
718#define LPSS_GPIODEF0_DMA1_D3		BIT(2)
719#define LPSS_GPIODEF0_DMA2_D3		BIT(3)
720#define LPSS_GPIODEF0_DMA_D3_MASK	GENMASK(3, 2)
721#define LPSS_GPIODEF0_DMA_LLP		BIT(13)
722
723static DEFINE_MUTEX(lpss_iosf_mutex);
724
725static void lpss_iosf_enter_d3_state(void)
726{
727	u32 value1 = 0;
728	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
729	u32 value2 = LPSS_PMCSR_D3hot;
730	u32 mask2 = LPSS_PMCSR_Dx_MASK;
731	/*
732	 * PMC provides an information about actual status of the LPSS devices.
733	 * Here we read the values related to LPSS power island, i.e. LPSS
734	 * devices, excluding both LPSS DMA controllers, along with SCC domain.
735	 */
736	u32 func_dis, d3_sts_0, pmc_status, pmc_mask = 0xfe000ffe;
737	int ret;
738
739	ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
740	if (ret)
741		return;
742
743	mutex_lock(&lpss_iosf_mutex);
744
745	ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
746	if (ret)
747		goto exit;
748
749	/*
750	 * Get the status of entire LPSS power island per device basis.
751	 * Shutdown both LPSS DMA controllers if and only if all other devices
752	 * are already in D3hot.
753	 */
754	pmc_status = (~(d3_sts_0 | func_dis)) & pmc_mask;
755	if (pmc_status)
756		goto exit;
757
758	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
759			LPSS_IOSF_PMCSR, value2, mask2);
760
761	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
762			LPSS_IOSF_PMCSR, value2, mask2);
763
764	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
765			LPSS_IOSF_GPIODEF0, value1, mask1);
766exit:
767	mutex_unlock(&lpss_iosf_mutex);
768}
769
770static void lpss_iosf_exit_d3_state(void)
771{
772	u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3 |
773		     LPSS_GPIODEF0_DMA_LLP;
774	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
775	u32 value2 = LPSS_PMCSR_D0;
776	u32 mask2 = LPSS_PMCSR_Dx_MASK;
777
778	mutex_lock(&lpss_iosf_mutex);
779
780	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
781			LPSS_IOSF_GPIODEF0, value1, mask1);
782
783	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
784			LPSS_IOSF_PMCSR, value2, mask2);
785
786	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
787			LPSS_IOSF_PMCSR, value2, mask2);
788
789	mutex_unlock(&lpss_iosf_mutex);
790}
791
792static int acpi_lpss_runtime_suspend(struct device *dev)
793{
794	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
795	int ret;
796
797	ret = pm_generic_runtime_suspend(dev);
798	if (ret)
799		return ret;
800
801	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
802		acpi_lpss_save_ctx(dev, pdata);
803
804	ret = acpi_dev_runtime_suspend(dev);
805
806	/*
807	 * This call must be last in the sequence, otherwise PMC will return
808	 * wrong status for devices being about to be powered off. See
809	 * lpss_iosf_enter_d3_state() for further information.
810	 */
811	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
812		lpss_iosf_enter_d3_state();
813
814	return ret;
815}
816
817static int acpi_lpss_runtime_resume(struct device *dev)
818{
819	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
820	int ret;
821
822	/*
823	 * This call is kept first to be in symmetry with
824	 * acpi_lpss_runtime_suspend() one.
825	 */
826	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
827		lpss_iosf_exit_d3_state();
828
829	ret = acpi_dev_runtime_resume(dev);
830	if (ret)
831		return ret;
832
833	acpi_lpss_d3_to_d0_delay(pdata);
834
835	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
836		acpi_lpss_restore_ctx(dev, pdata);
837
838	return pm_generic_runtime_resume(dev);
839}
840#endif /* CONFIG_PM */
841
842static struct dev_pm_domain acpi_lpss_pm_domain = {
843#ifdef CONFIG_PM
844	.activate = acpi_lpss_activate,
845	.dismiss = acpi_lpss_dismiss,
846#endif
847	.ops = {
848#ifdef CONFIG_PM
849#ifdef CONFIG_PM_SLEEP
850		.prepare = acpi_subsys_prepare,
851		.complete = pm_complete_with_resume_check,
852		.suspend = acpi_subsys_suspend,
853		.suspend_late = acpi_lpss_suspend_late,
854		.resume_early = acpi_lpss_resume_early,
855		.freeze = acpi_subsys_freeze,
856		.poweroff = acpi_subsys_suspend,
857		.poweroff_late = acpi_lpss_suspend_late,
858		.restore_early = acpi_lpss_resume_early,
859#endif
860		.runtime_suspend = acpi_lpss_runtime_suspend,
861		.runtime_resume = acpi_lpss_runtime_resume,
862#endif
863	},
864};
865
866static int acpi_lpss_platform_notify(struct notifier_block *nb,
867				     unsigned long action, void *data)
868{
869	struct platform_device *pdev = to_platform_device(data);
870	struct lpss_private_data *pdata;
871	struct acpi_device *adev;
872	const struct acpi_device_id *id;
873
874	id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
875	if (!id || !id->driver_data)
876		return 0;
877
878	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
879		return 0;
880
881	pdata = acpi_driver_data(adev);
882	if (!pdata)
883		return 0;
884
885	if (pdata->mmio_base &&
886	    pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
887		dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
888		return 0;
889	}
890
891	switch (action) {
892	case BUS_NOTIFY_BIND_DRIVER:
893		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
894		break;
895	case BUS_NOTIFY_DRIVER_NOT_BOUND:
896	case BUS_NOTIFY_UNBOUND_DRIVER:
897		dev_pm_domain_set(&pdev->dev, NULL);
898		break;
899	case BUS_NOTIFY_ADD_DEVICE:
900		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
901		if (pdata->dev_desc->flags & LPSS_LTR)
902			return sysfs_create_group(&pdev->dev.kobj,
903						  &lpss_attr_group);
904		break;
905	case BUS_NOTIFY_DEL_DEVICE:
906		if (pdata->dev_desc->flags & LPSS_LTR)
907			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
908		dev_pm_domain_set(&pdev->dev, NULL);
909		break;
910	default:
911		break;
912	}
913
914	return 0;
915}
916
917static struct notifier_block acpi_lpss_nb = {
918	.notifier_call = acpi_lpss_platform_notify,
919};
920
921static void acpi_lpss_bind(struct device *dev)
922{
923	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
924
925	if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
926		return;
927
928	if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
929		dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
930	else
931		dev_err(dev, "MMIO size insufficient to access LTR\n");
932}
933
934static void acpi_lpss_unbind(struct device *dev)
935{
936	dev->power.set_latency_tolerance = NULL;
937}
938
939static struct acpi_scan_handler lpss_handler = {
940	.ids = acpi_lpss_device_ids,
941	.attach = acpi_lpss_create_device,
942	.bind = acpi_lpss_bind,
943	.unbind = acpi_lpss_unbind,
944};
945
946void __init acpi_lpss_init(void)
947{
948	const struct x86_cpu_id *id;
949	int ret;
950
951	ret = lpt_clk_init();
952	if (ret)
953		return;
954
955	id = x86_match_cpu(lpss_cpu_ids);
956	if (id)
957		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
958
959	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
960	acpi_scan_add_handler(&lpss_handler);
961}
962
963#else
964
965static struct acpi_scan_handler lpss_handler = {
966	.ids = acpi_lpss_device_ids,
967};
968
969void __init acpi_lpss_init(void)
970{
971	acpi_scan_add_handler(&lpss_handler);
972}
973
974#endif /* CONFIG_X86_INTEL_LPSS */