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>
25 ACPI_MODULE_NAME("acpi_lpss");
27 #define LPSS_CLK_SIZE 0x04
28 #define LPSS_LTR_SIZE 0x18
30 /* Offsets relative to LPSS_PRIVATE_OFFSET */
31 #define LPSS_GENERAL 0x08
32 #define LPSS_GENERAL_LTR_MODE_SW BIT(2)
33 #define LPSS_SW_LTR 0x10
34 #define LPSS_AUTO_LTR 0x14
36 struct lpss_device_desc {
38 const char *clkdev_name;
40 unsigned int prv_offset;
43 static struct lpss_device_desc lpss_dma_desc = {
45 .clkdev_name = "hclk",
48 struct lpss_private_data {
49 void __iomem *mmio_base;
50 resource_size_t mmio_size;
52 const struct lpss_device_desc *dev_desc;
55 static struct lpss_device_desc lpt_dev_desc = {
61 static struct lpss_device_desc lpt_sdio_dev_desc = {
66 static const struct acpi_device_id acpi_lpss_device_ids[] = {
67 /* Generic LPSS devices */
68 { "INTL9C60", (unsigned long)&lpss_dma_desc },
70 /* Lynxpoint LPSS devices */
71 { "INT33C0", (unsigned long)&lpt_dev_desc },
72 { "INT33C1", (unsigned long)&lpt_dev_desc },
73 { "INT33C2", (unsigned long)&lpt_dev_desc },
74 { "INT33C3", (unsigned long)&lpt_dev_desc },
75 { "INT33C4", (unsigned long)&lpt_dev_desc },
76 { "INT33C5", (unsigned long)&lpt_dev_desc },
77 { "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
83 static int is_memory(struct acpi_resource *res, void *not_used)
86 return !acpi_dev_resource_memory(res, &r);
89 /* LPSS main clock device. */
90 static struct platform_device *lpss_clk_dev;
92 static inline void lpt_register_clock_device(void)
94 lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
97 static int register_device_clock(struct acpi_device *adev,
98 struct lpss_private_data *pdata)
100 const struct lpss_device_desc *dev_desc = pdata->dev_desc;
101 struct lpss_clk_data *clk_data;
104 lpt_register_clock_device();
106 clk_data = platform_get_drvdata(lpss_clk_dev);
110 if (dev_desc->clkdev_name) {
111 clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
112 dev_name(&adev->dev));
116 if (!pdata->mmio_base
117 || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
120 pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev),
122 pdata->mmio_base + dev_desc->prv_offset,
124 if (IS_ERR(pdata->clk))
125 return PTR_ERR(pdata->clk);
127 clk_register_clkdev(pdata->clk, NULL, dev_name(&adev->dev));
131 static int acpi_lpss_create_device(struct acpi_device *adev,
132 const struct acpi_device_id *id)
134 struct lpss_device_desc *dev_desc;
135 struct lpss_private_data *pdata;
136 struct resource_list_entry *rentry;
137 struct list_head resource_list;
140 dev_desc = (struct lpss_device_desc *)id->driver_data;
142 return acpi_create_platform_device(adev, id);
144 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
148 INIT_LIST_HEAD(&resource_list);
149 ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
153 list_for_each_entry(rentry, &resource_list, node)
154 if (resource_type(&rentry->res) == IORESOURCE_MEM) {
155 pdata->mmio_size = resource_size(&rentry->res);
156 pdata->mmio_base = ioremap(rentry->res.start,
158 pdata->dev_desc = dev_desc;
162 acpi_dev_free_resource_list(&resource_list);
164 if (dev_desc->clk_required) {
165 ret = register_device_clock(adev, pdata);
167 /* Skip the device, but continue the namespace scan. */
174 * This works around a known issue in ACPI tables where LPSS devices
175 * have _PS0 and _PS3 without _PSC (and no power resources), so
176 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
178 ret = acpi_device_fix_up_power(adev);
180 /* Skip the device, but continue the namespace scan. */
185 adev->driver_data = pdata;
186 ret = acpi_create_platform_device(adev, id);
190 adev->driver_data = NULL;
197 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
199 struct acpi_device *adev;
200 struct lpss_private_data *pdata;
204 ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
208 spin_lock_irqsave(&dev->power.lock, flags);
209 if (pm_runtime_suspended(dev)) {
213 pdata = acpi_driver_data(adev);
214 if (WARN_ON(!pdata || !pdata->mmio_base)) {
218 *val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
221 spin_unlock_irqrestore(&dev->power.lock, flags);
225 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
232 reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
233 ret = lpss_reg_read(dev, reg, <r_value);
237 return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
240 static ssize_t lpss_ltr_mode_show(struct device *dev,
241 struct device_attribute *attr, char *buf)
247 ret = lpss_reg_read(dev, LPSS_GENERAL, <r_mode);
251 outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
252 return sprintf(buf, "%s\n", outstr);
255 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
256 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
257 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
259 static struct attribute *lpss_attrs[] = {
260 &dev_attr_auto_ltr.attr,
261 &dev_attr_sw_ltr.attr,
262 &dev_attr_ltr_mode.attr,
266 static struct attribute_group lpss_attr_group = {
271 static int acpi_lpss_platform_notify(struct notifier_block *nb,
272 unsigned long action, void *data)
274 struct platform_device *pdev = to_platform_device(data);
275 struct lpss_private_data *pdata;
276 struct acpi_device *adev;
277 const struct acpi_device_id *id;
280 id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
281 if (!id || !id->driver_data)
284 if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
287 pdata = acpi_driver_data(adev);
288 if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
291 if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
292 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
296 if (action == BUS_NOTIFY_ADD_DEVICE)
297 ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
298 else if (action == BUS_NOTIFY_DEL_DEVICE)
299 sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
304 static struct notifier_block acpi_lpss_nb = {
305 .notifier_call = acpi_lpss_platform_notify,
308 static struct acpi_scan_handler lpss_handler = {
309 .ids = acpi_lpss_device_ids,
310 .attach = acpi_lpss_create_device,
313 void __init acpi_lpss_init(void)
315 if (!lpt_clk_init()) {
316 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
317 acpi_scan_add_handler(&lpss_handler);