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f58b082a RW |
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> | |
2e0f8822 | 21 | #include <linux/pm_runtime.h> |
f58b082a RW |
22 | |
23 | #include "internal.h" | |
24 | ||
25 | ACPI_MODULE_NAME("acpi_lpss"); | |
26 | ||
f58b082a | 27 | #define LPSS_CLK_SIZE 0x04 |
2e0f8822 RW |
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 | |
f58b082a RW |
35 | |
36 | struct lpss_device_desc { | |
37 | bool clk_required; | |
b59cc200 | 38 | const char *clkdev_name; |
2e0f8822 RW |
39 | bool ltr_required; |
40 | unsigned int prv_offset; | |
f58b082a RW |
41 | }; |
42 | ||
b59cc200 RW |
43 | static struct lpss_device_desc lpss_dma_desc = { |
44 | .clk_required = true, | |
45 | .clkdev_name = "hclk", | |
46 | }; | |
47 | ||
f58b082a RW |
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, | |
2e0f8822 RW |
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, | |
f58b082a RW |
64 | }; |
65 | ||
66 | static const struct acpi_device_id acpi_lpss_device_ids[] = { | |
b59cc200 RW |
67 | /* Generic LPSS devices */ |
68 | { "INTL9C60", (unsigned long)&lpss_dma_desc }, | |
69 | ||
f58b082a RW |
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 }, | |
2e0f8822 | 77 | { "INT33C6", (unsigned long)&lpt_sdio_dev_desc }, |
f58b082a RW |
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; | |
b59cc200 | 101 | struct lpss_clk_data *clk_data; |
f58b082a RW |
102 | |
103 | if (!lpss_clk_dev) | |
104 | lpt_register_clock_device(); | |
105 | ||
b59cc200 RW |
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 | |
2e0f8822 | 117 | || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE) |
f58b082a RW |
118 | return -ENODATA; |
119 | ||
120 | pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev), | |
b59cc200 | 121 | clk_data->name, 0, |
2e0f8822 | 122 | pdata->mmio_base + dev_desc->prv_offset, |
f58b082a RW |
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 | pdata->dev_desc = dev_desc; | |
159 | break; | |
160 | } | |
161 | ||
162 | acpi_dev_free_resource_list(&resource_list); | |
163 | ||
164 | if (dev_desc->clk_required) { | |
165 | ret = register_device_clock(adev, pdata); | |
166 | if (ret) { | |
b9e95fc6 RW |
167 | /* Skip the device, but continue the namespace scan. */ |
168 | ret = 0; | |
169 | goto err_out; | |
f58b082a RW |
170 | } |
171 | } | |
172 | ||
b9e95fc6 RW |
173 | /* |
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. | |
177 | */ | |
178 | ret = acpi_device_fix_up_power(adev); | |
179 | if (ret) { | |
180 | /* Skip the device, but continue the namespace scan. */ | |
181 | ret = 0; | |
182 | goto err_out; | |
183 | } | |
184 | ||
f58b082a RW |
185 | adev->driver_data = pdata; |
186 | ret = acpi_create_platform_device(adev, id); | |
187 | if (ret > 0) | |
188 | return ret; | |
189 | ||
190 | adev->driver_data = NULL; | |
191 | ||
192 | err_out: | |
193 | kfree(pdata); | |
194 | return ret; | |
195 | } | |
196 | ||
2e0f8822 RW |
197 | static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val) |
198 | { | |
199 | struct acpi_device *adev; | |
200 | struct lpss_private_data *pdata; | |
201 | unsigned long flags; | |
202 | int ret; | |
203 | ||
204 | ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev); | |
205 | if (WARN_ON(ret)) | |
206 | return ret; | |
207 | ||
208 | spin_lock_irqsave(&dev->power.lock, flags); | |
209 | if (pm_runtime_suspended(dev)) { | |
210 | ret = -EAGAIN; | |
211 | goto out; | |
212 | } | |
213 | pdata = acpi_driver_data(adev); | |
214 | if (WARN_ON(!pdata || !pdata->mmio_base)) { | |
215 | ret = -ENODEV; | |
216 | goto out; | |
217 | } | |
218 | *val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg); | |
219 | ||
220 | out: | |
221 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
222 | return ret; | |
223 | } | |
224 | ||
225 | static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr, | |
226 | char *buf) | |
227 | { | |
228 | u32 ltr_value = 0; | |
229 | unsigned int reg; | |
230 | int ret; | |
231 | ||
232 | reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR; | |
233 | ret = lpss_reg_read(dev, reg, <r_value); | |
234 | if (ret) | |
235 | return ret; | |
236 | ||
237 | return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value); | |
238 | } | |
239 | ||
240 | static ssize_t lpss_ltr_mode_show(struct device *dev, | |
241 | struct device_attribute *attr, char *buf) | |
242 | { | |
243 | u32 ltr_mode = 0; | |
244 | char *outstr; | |
245 | int ret; | |
246 | ||
247 | ret = lpss_reg_read(dev, LPSS_GENERAL, <r_mode); | |
248 | if (ret) | |
249 | return ret; | |
250 | ||
251 | outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto"; | |
252 | return sprintf(buf, "%s\n", outstr); | |
253 | } | |
254 | ||
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); | |
258 | ||
259 | static struct attribute *lpss_attrs[] = { | |
260 | &dev_attr_auto_ltr.attr, | |
261 | &dev_attr_sw_ltr.attr, | |
262 | &dev_attr_ltr_mode.attr, | |
263 | NULL, | |
264 | }; | |
265 | ||
266 | static struct attribute_group lpss_attr_group = { | |
267 | .attrs = lpss_attrs, | |
268 | .name = "lpss_ltr", | |
269 | }; | |
270 | ||
271 | static int acpi_lpss_platform_notify(struct notifier_block *nb, | |
272 | unsigned long action, void *data) | |
273 | { | |
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; | |
278 | int ret = 0; | |
279 | ||
280 | id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev); | |
281 | if (!id || !id->driver_data) | |
282 | return 0; | |
283 | ||
284 | if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev)) | |
285 | return 0; | |
286 | ||
287 | pdata = acpi_driver_data(adev); | |
288 | if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required) | |
289 | return 0; | |
290 | ||
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"); | |
293 | return 0; | |
294 | } | |
295 | ||
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); | |
300 | ||
301 | return ret; | |
302 | } | |
303 | ||
304 | static struct notifier_block acpi_lpss_nb = { | |
305 | .notifier_call = acpi_lpss_platform_notify, | |
306 | }; | |
307 | ||
f58b082a RW |
308 | static struct acpi_scan_handler lpss_handler = { |
309 | .ids = acpi_lpss_device_ids, | |
310 | .attach = acpi_lpss_create_device, | |
311 | }; | |
312 | ||
313 | void __init acpi_lpss_init(void) | |
314 | { | |
2e0f8822 RW |
315 | if (!lpt_clk_init()) { |
316 | bus_register_notifier(&platform_bus_type, &acpi_lpss_nb); | |
f58b082a | 317 | acpi_scan_add_handler(&lpss_handler); |
2e0f8822 | 318 | } |
f58b082a | 319 | } |