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[linux-3.10.git] / drivers / acpi / acpi_lpss.c
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/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
23 #include "internal.h"
24
25 ACPI_MODULE_NAME("acpi_lpss");
26
27 #define LPSS_CLK_SIZE   0x04
28 #define LPSS_LTR_SIZE   0x18
29
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
35
36 struct lpss_device_desc {
37         bool clk_required;
38         const char *clkdev_name;
39         bool ltr_required;
40         unsigned int prv_offset;
41 };
42
43 static struct lpss_device_desc lpss_dma_desc = {
44         .clk_required = true,
45         .clkdev_name = "hclk",
46 };
47
48 struct lpss_private_data {
49         void __iomem *mmio_base;
50         resource_size_t mmio_size;
51         struct clk *clk;
52         const struct lpss_device_desc *dev_desc;
53 };
54
55 static struct lpss_device_desc lpt_dev_desc = {
56         .clk_required = true,
57         .prv_offset = 0x800,
58         .ltr_required = true,
59 };
60
61 static struct lpss_device_desc lpt_sdio_dev_desc = {
62         .prv_offset = 0x1000,
63         .ltr_required = true,
64 };
65
66 static const struct acpi_device_id acpi_lpss_device_ids[] = {
67         /* Generic LPSS devices */
68         { "INTL9C60", (unsigned long)&lpss_dma_desc },
69
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 },
78         { "INT33C7", },
79
80         { }
81 };
82
83 static int is_memory(struct acpi_resource *res, void *not_used)
84 {
85         struct resource r;
86         return !acpi_dev_resource_memory(res, &r);
87 }
88
89 /* LPSS main clock device. */
90 static struct platform_device *lpss_clk_dev;
91
92 static inline void lpt_register_clock_device(void)
93 {
94         lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
95 }
96
97 static int register_device_clock(struct acpi_device *adev,
98                                  struct lpss_private_data *pdata)
99 {
100         const struct lpss_device_desc *dev_desc = pdata->dev_desc;
101         struct lpss_clk_data *clk_data;
102
103         if (!lpss_clk_dev)
104                 lpt_register_clock_device();
105
106         clk_data = platform_get_drvdata(lpss_clk_dev);
107         if (!clk_data)
108                 return -ENODEV;
109
110         if (dev_desc->clkdev_name) {
111                 clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
112                                     dev_name(&adev->dev));
113                 return 0;
114         }
115
116         if (!pdata->mmio_base
117             || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
118                 return -ENODATA;
119
120         pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev),
121                                        clk_data->name, 0,
122                                        pdata->mmio_base + dev_desc->prv_offset,
123                                        0, 0, NULL);
124         if (IS_ERR(pdata->clk))
125                 return PTR_ERR(pdata->clk);
126
127         clk_register_clkdev(pdata->clk, NULL, dev_name(&adev->dev));
128         return 0;
129 }
130
131 static int acpi_lpss_create_device(struct acpi_device *adev,
132                                    const struct acpi_device_id *id)
133 {
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;
138         int ret;
139
140         dev_desc = (struct lpss_device_desc *)id->driver_data;
141         if (!dev_desc)
142                 return acpi_create_platform_device(adev, id);
143
144         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
145         if (!pdata)
146                 return -ENOMEM;
147
148         INIT_LIST_HEAD(&resource_list);
149         ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
150         if (ret < 0)
151                 goto err_out;
152
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,
157                                                    pdata->mmio_size);
158                         break;
159                 }
160
161         acpi_dev_free_resource_list(&resource_list);
162
163         pdata->dev_desc = dev_desc;
164
165         if (dev_desc->clk_required) {
166                 ret = register_device_clock(adev, pdata);
167                 if (ret) {
168                         /* Skip the device, but continue the namespace scan. */
169                         ret = 0;
170                         goto err_out;
171                 }
172         }
173
174         /*
175          * This works around a known issue in ACPI tables where LPSS devices
176          * have _PS0 and _PS3 without _PSC (and no power resources), so
177          * acpi_bus_init_power() will assume that the BIOS has put them into D0.
178          */
179         ret = acpi_device_fix_up_power(adev);
180         if (ret) {
181                 /* Skip the device, but continue the namespace scan. */
182                 ret = 0;
183                 goto err_out;
184         }
185
186         adev->driver_data = pdata;
187         ret = acpi_create_platform_device(adev, id);
188         if (ret > 0)
189                 return ret;
190
191         adev->driver_data = NULL;
192
193  err_out:
194         kfree(pdata);
195         return ret;
196 }
197
198 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
199 {
200         struct acpi_device *adev;
201         struct lpss_private_data *pdata;
202         unsigned long flags;
203         int ret;
204
205         ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
206         if (WARN_ON(ret))
207                 return ret;
208
209         spin_lock_irqsave(&dev->power.lock, flags);
210         if (pm_runtime_suspended(dev)) {
211                 ret = -EAGAIN;
212                 goto out;
213         }
214         pdata = acpi_driver_data(adev);
215         if (WARN_ON(!pdata || !pdata->mmio_base)) {
216                 ret = -ENODEV;
217                 goto out;
218         }
219         *val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
220
221  out:
222         spin_unlock_irqrestore(&dev->power.lock, flags);
223         return ret;
224 }
225
226 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
227                              char *buf)
228 {
229         u32 ltr_value = 0;
230         unsigned int reg;
231         int ret;
232
233         reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
234         ret = lpss_reg_read(dev, reg, &ltr_value);
235         if (ret)
236                 return ret;
237
238         return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
239 }
240
241 static ssize_t lpss_ltr_mode_show(struct device *dev,
242                                   struct device_attribute *attr, char *buf)
243 {
244         u32 ltr_mode = 0;
245         char *outstr;
246         int ret;
247
248         ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
249         if (ret)
250                 return ret;
251
252         outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
253         return sprintf(buf, "%s\n", outstr);
254 }
255
256 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
257 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
258 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
259
260 static struct attribute *lpss_attrs[] = {
261         &dev_attr_auto_ltr.attr,
262         &dev_attr_sw_ltr.attr,
263         &dev_attr_ltr_mode.attr,
264         NULL,
265 };
266
267 static struct attribute_group lpss_attr_group = {
268         .attrs = lpss_attrs,
269         .name = "lpss_ltr",
270 };
271
272 static int acpi_lpss_platform_notify(struct notifier_block *nb,
273                                      unsigned long action, void *data)
274 {
275         struct platform_device *pdev = to_platform_device(data);
276         struct lpss_private_data *pdata;
277         struct acpi_device *adev;
278         const struct acpi_device_id *id;
279         int ret = 0;
280
281         id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
282         if (!id || !id->driver_data)
283                 return 0;
284
285         if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
286                 return 0;
287
288         pdata = acpi_driver_data(adev);
289         if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
290                 return 0;
291
292         if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
293                 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
294                 return 0;
295         }
296
297         if (action == BUS_NOTIFY_ADD_DEVICE)
298                 ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
299         else if (action == BUS_NOTIFY_DEL_DEVICE)
300                 sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
301
302         return ret;
303 }
304
305 static struct notifier_block acpi_lpss_nb = {
306         .notifier_call = acpi_lpss_platform_notify,
307 };
308
309 static struct acpi_scan_handler lpss_handler = {
310         .ids = acpi_lpss_device_ids,
311         .attach = acpi_lpss_create_device,
312 };
313
314 void __init acpi_lpss_init(void)
315 {
316         if (!lpt_clk_init()) {
317                 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
318                 acpi_scan_add_handler(&lpss_handler);
319         }
320 }