2 * ACPI support for Intel Lynxpoint LPSS.
4 * Copyright (C) 2013, Intel Corporation
5 * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
6 * Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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.
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>
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>
26 ACPI_MODULE_NAME("acpi_lpss");
28 #ifdef CONFIG_X86_INTEL_LPSS
30 #define LPSS_ADDR(desc) ((unsigned long)&desc)
32 #define LPSS_CLK_SIZE 0x04
33 #define LPSS_LTR_SIZE 0x18
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)
55 #define LPSS_PRV_REG_COUNT 9
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)
64 struct lpss_private_data;
66 struct lpss_device_desc {
68 const char *clk_con_id;
69 unsigned int prv_offset;
70 size_t prv_size_override;
71 void (*setup)(struct lpss_private_data *pdata);
74 static struct lpss_device_desc lpss_dma_desc = {
78 struct lpss_private_data {
79 void __iomem *mmio_base;
80 resource_size_t mmio_size;
81 unsigned int fixed_clk_rate;
83 const struct lpss_device_desc *dev_desc;
84 u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
87 /* UART Component Parameter Register */
88 #define LPSS_UART_CPR 0xF4
89 #define LPSS_UART_CPR_AFCE BIT(4)
91 static void lpss_uart_setup(struct lpss_private_data *pdata)
96 offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
97 val = readl(pdata->mmio_base + offset);
98 writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
100 val = readl(pdata->mmio_base + LPSS_UART_CPR);
101 if (!(val & LPSS_UART_CPR_AFCE)) {
102 offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
103 val = readl(pdata->mmio_base + offset);
104 val |= LPSS_GENERAL_UART_RTS_OVRD;
105 writel(val, pdata->mmio_base + offset);
109 static void lpss_deassert_reset(struct lpss_private_data *pdata)
114 offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
115 val = readl(pdata->mmio_base + offset);
116 val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
117 writel(val, pdata->mmio_base + offset);
120 #define LPSS_I2C_ENABLE 0x6c
122 static void byt_i2c_setup(struct lpss_private_data *pdata)
124 lpss_deassert_reset(pdata);
126 if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
127 pdata->fixed_clk_rate = 133000000;
129 writel(0, pdata->mmio_base + LPSS_I2C_ENABLE);
132 static const struct lpss_device_desc lpt_dev_desc = {
133 .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
137 static const struct lpss_device_desc lpt_i2c_dev_desc = {
138 .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR,
142 static const struct lpss_device_desc lpt_uart_dev_desc = {
143 .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
144 .clk_con_id = "baudclk",
146 .setup = lpss_uart_setup,
149 static const struct lpss_device_desc lpt_sdio_dev_desc = {
151 .prv_offset = 0x1000,
152 .prv_size_override = 0x1018,
155 static const struct lpss_device_desc byt_pwm_dev_desc = {
156 .flags = LPSS_SAVE_CTX,
159 static const struct lpss_device_desc byt_uart_dev_desc = {
160 .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
161 .clk_con_id = "baudclk",
163 .setup = lpss_uart_setup,
166 static const struct lpss_device_desc byt_spi_dev_desc = {
167 .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
171 static const struct lpss_device_desc byt_sdio_dev_desc = {
175 static const struct lpss_device_desc byt_i2c_dev_desc = {
176 .flags = LPSS_CLK | LPSS_SAVE_CTX,
178 .setup = byt_i2c_setup,
181 static struct lpss_device_desc bsw_spi_dev_desc = {
182 .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
184 .setup = lpss_deassert_reset,
189 #define LPSS_ADDR(desc) (0UL)
191 #endif /* CONFIG_X86_INTEL_LPSS */
193 static const struct acpi_device_id acpi_lpss_device_ids[] = {
194 /* Generic LPSS devices */
195 { "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
197 /* Lynxpoint LPSS devices */
198 { "INT33C0", LPSS_ADDR(lpt_dev_desc) },
199 { "INT33C1", LPSS_ADDR(lpt_dev_desc) },
200 { "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
201 { "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
202 { "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
203 { "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
204 { "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
207 /* BayTrail LPSS devices */
208 { "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
209 { "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
210 { "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
211 { "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
212 { "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
216 /* Braswell LPSS devices */
217 { "80862288", LPSS_ADDR(byt_pwm_dev_desc) },
218 { "8086228A", LPSS_ADDR(byt_uart_dev_desc) },
219 { "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
220 { "808622C1", LPSS_ADDR(byt_i2c_dev_desc) },
222 { "INT3430", LPSS_ADDR(lpt_dev_desc) },
223 { "INT3431", LPSS_ADDR(lpt_dev_desc) },
224 { "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
225 { "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
226 { "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
227 { "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
228 { "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
231 /* Wildcat Point LPSS devices */
232 { "INT3438", LPSS_ADDR(lpt_dev_desc) },
237 #ifdef CONFIG_X86_INTEL_LPSS
239 static int is_memory(struct acpi_resource *res, void *not_used)
242 return !acpi_dev_resource_memory(res, &r);
245 /* LPSS main clock device. */
246 static struct platform_device *lpss_clk_dev;
248 static inline void lpt_register_clock_device(void)
250 lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
253 static int register_device_clock(struct acpi_device *adev,
254 struct lpss_private_data *pdata)
256 const struct lpss_device_desc *dev_desc = pdata->dev_desc;
257 const char *devname = dev_name(&adev->dev);
258 struct clk *clk = ERR_PTR(-ENODEV);
259 struct lpss_clk_data *clk_data;
260 const char *parent, *clk_name;
261 void __iomem *prv_base;
264 lpt_register_clock_device();
266 clk_data = platform_get_drvdata(lpss_clk_dev);
271 if (!pdata->mmio_base
272 || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
275 parent = clk_data->name;
276 prv_base = pdata->mmio_base + dev_desc->prv_offset;
278 if (pdata->fixed_clk_rate) {
279 clk = clk_register_fixed_rate(NULL, devname, parent, 0,
280 pdata->fixed_clk_rate);
284 if (dev_desc->flags & LPSS_CLK_GATE) {
285 clk = clk_register_gate(NULL, devname, parent, 0,
286 prv_base, 0, 0, NULL);
290 if (dev_desc->flags & LPSS_CLK_DIVIDER) {
291 /* Prevent division by zero */
292 if (!readl(prv_base))
293 writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
295 clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
298 clk = clk_register_fractional_divider(NULL, clk_name, parent,
300 1, 15, 16, 15, 0, NULL);
303 clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
308 clk = clk_register_gate(NULL, clk_name, parent,
309 CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
310 prv_base, 31, 0, NULL);
319 clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
323 static int acpi_lpss_create_device(struct acpi_device *adev,
324 const struct acpi_device_id *id)
326 const struct lpss_device_desc *dev_desc;
327 struct lpss_private_data *pdata;
328 struct resource_entry *rentry;
329 struct list_head resource_list;
330 struct platform_device *pdev;
333 dev_desc = (const struct lpss_device_desc *)id->driver_data;
335 pdev = acpi_create_platform_device(adev);
336 return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
338 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
342 INIT_LIST_HEAD(&resource_list);
343 ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
347 list_for_each_entry(rentry, &resource_list, node)
348 if (resource_type(rentry->res) == IORESOURCE_MEM) {
349 if (dev_desc->prv_size_override)
350 pdata->mmio_size = dev_desc->prv_size_override;
352 pdata->mmio_size = resource_size(rentry->res);
353 pdata->mmio_base = ioremap(rentry->res->start,
358 acpi_dev_free_resource_list(&resource_list);
360 if (!pdata->mmio_base) {
365 pdata->dev_desc = dev_desc;
368 dev_desc->setup(pdata);
370 if (dev_desc->flags & LPSS_CLK) {
371 ret = register_device_clock(adev, pdata);
373 /* Skip the device, but continue the namespace scan. */
380 * This works around a known issue in ACPI tables where LPSS devices
381 * have _PS0 and _PS3 without _PSC (and no power resources), so
382 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
384 ret = acpi_device_fix_up_power(adev);
386 /* Skip the device, but continue the namespace scan. */
391 adev->driver_data = pdata;
392 pdev = acpi_create_platform_device(adev);
393 if (!IS_ERR_OR_NULL(pdev)) {
398 adev->driver_data = NULL;
405 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
407 return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
410 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
413 writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
416 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
418 struct acpi_device *adev;
419 struct lpss_private_data *pdata;
423 ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
427 spin_lock_irqsave(&dev->power.lock, flags);
428 if (pm_runtime_suspended(dev)) {
432 pdata = acpi_driver_data(adev);
433 if (WARN_ON(!pdata || !pdata->mmio_base)) {
437 *val = __lpss_reg_read(pdata, reg);
440 spin_unlock_irqrestore(&dev->power.lock, flags);
444 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
451 reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
452 ret = lpss_reg_read(dev, reg, <r_value);
456 return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
459 static ssize_t lpss_ltr_mode_show(struct device *dev,
460 struct device_attribute *attr, char *buf)
466 ret = lpss_reg_read(dev, LPSS_GENERAL, <r_mode);
470 outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
471 return sprintf(buf, "%s\n", outstr);
474 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
475 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
476 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
478 static struct attribute *lpss_attrs[] = {
479 &dev_attr_auto_ltr.attr,
480 &dev_attr_sw_ltr.attr,
481 &dev_attr_ltr_mode.attr,
485 static struct attribute_group lpss_attr_group = {
490 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
492 struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
493 u32 ltr_mode, ltr_val;
495 ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
497 if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
498 ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
499 __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
503 ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
504 if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
505 ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
506 val = LPSS_LTR_MAX_VAL;
507 } else if (val > LPSS_LTR_MAX_VAL) {
508 ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
509 val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
511 ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
514 __lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
515 if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
516 ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
517 __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
523 * acpi_lpss_save_ctx() - Save the private registers of LPSS device
525 * @pdata: pointer to the private data of the LPSS device
527 * Most LPSS devices have private registers which may loose their context when
528 * the device is powered down. acpi_lpss_save_ctx() saves those registers into
531 static void acpi_lpss_save_ctx(struct device *dev,
532 struct lpss_private_data *pdata)
536 for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
537 unsigned long offset = i * sizeof(u32);
539 pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
540 dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
541 pdata->prv_reg_ctx[i], offset);
546 * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
548 * @pdata: pointer to the private data of the LPSS device
550 * Restores the registers that were previously stored with acpi_lpss_save_ctx().
552 static void acpi_lpss_restore_ctx(struct device *dev,
553 struct lpss_private_data *pdata)
558 * The following delay is needed or the subsequent write operations may
559 * fail. The LPSS devices are actually PCI devices and the PCI spec
560 * expects 10ms delay before the device can be accessed after D3 to D0
565 for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
566 unsigned long offset = i * sizeof(u32);
568 __lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
569 dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
570 pdata->prv_reg_ctx[i], offset);
574 #ifdef CONFIG_PM_SLEEP
575 static int acpi_lpss_suspend_late(struct device *dev)
577 struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
580 ret = pm_generic_suspend_late(dev);
584 if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
585 acpi_lpss_save_ctx(dev, pdata);
587 return acpi_dev_suspend_late(dev);
590 static int acpi_lpss_resume_early(struct device *dev)
592 struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
595 ret = acpi_dev_resume_early(dev);
599 if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
600 acpi_lpss_restore_ctx(dev, pdata);
602 return pm_generic_resume_early(dev);
604 #endif /* CONFIG_PM_SLEEP */
606 static int acpi_lpss_runtime_suspend(struct device *dev)
608 struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
611 ret = pm_generic_runtime_suspend(dev);
615 if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
616 acpi_lpss_save_ctx(dev, pdata);
618 return acpi_dev_runtime_suspend(dev);
621 static int acpi_lpss_runtime_resume(struct device *dev)
623 struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
626 ret = acpi_dev_runtime_resume(dev);
630 if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
631 acpi_lpss_restore_ctx(dev, pdata);
633 return pm_generic_runtime_resume(dev);
635 #endif /* CONFIG_PM */
637 static struct dev_pm_domain acpi_lpss_pm_domain = {
640 #ifdef CONFIG_PM_SLEEP
641 .prepare = acpi_subsys_prepare,
642 .complete = acpi_subsys_complete,
643 .suspend = acpi_subsys_suspend,
644 .suspend_late = acpi_lpss_suspend_late,
645 .resume_early = acpi_lpss_resume_early,
646 .freeze = acpi_subsys_freeze,
647 .poweroff = acpi_subsys_suspend,
648 .poweroff_late = acpi_lpss_suspend_late,
649 .restore_early = acpi_lpss_resume_early,
651 .runtime_suspend = acpi_lpss_runtime_suspend,
652 .runtime_resume = acpi_lpss_runtime_resume,
657 static int acpi_lpss_platform_notify(struct notifier_block *nb,
658 unsigned long action, void *data)
660 struct platform_device *pdev = to_platform_device(data);
661 struct lpss_private_data *pdata;
662 struct acpi_device *adev;
663 const struct acpi_device_id *id;
665 id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
666 if (!id || !id->driver_data)
669 if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
672 pdata = acpi_driver_data(adev);
676 if (pdata->mmio_base &&
677 pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
678 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
683 case BUS_NOTIFY_ADD_DEVICE:
684 pdev->dev.pm_domain = &acpi_lpss_pm_domain;
685 if (pdata->dev_desc->flags & LPSS_LTR)
686 return sysfs_create_group(&pdev->dev.kobj,
689 case BUS_NOTIFY_DEL_DEVICE:
690 if (pdata->dev_desc->flags & LPSS_LTR)
691 sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
692 pdev->dev.pm_domain = NULL;
701 static struct notifier_block acpi_lpss_nb = {
702 .notifier_call = acpi_lpss_platform_notify,
705 static void acpi_lpss_bind(struct device *dev)
707 struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
709 if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
712 if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
713 dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
715 dev_err(dev, "MMIO size insufficient to access LTR\n");
718 static void acpi_lpss_unbind(struct device *dev)
720 dev->power.set_latency_tolerance = NULL;
723 static struct acpi_scan_handler lpss_handler = {
724 .ids = acpi_lpss_device_ids,
725 .attach = acpi_lpss_create_device,
726 .bind = acpi_lpss_bind,
727 .unbind = acpi_lpss_unbind,
730 void __init acpi_lpss_init(void)
732 if (!lpt_clk_init()) {
733 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
734 acpi_scan_add_handler(&lpss_handler);
740 static struct acpi_scan_handler lpss_handler = {
741 .ids = acpi_lpss_device_ids,
744 void __init acpi_lpss_init(void)
746 acpi_scan_add_handler(&lpss_handler);
749 #endif /* CONFIG_X86_INTEL_LPSS */