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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; | |
38 | const char *clk_parent; | |
2e0f8822 RW |
39 | bool ltr_required; |
40 | unsigned int prv_offset; | |
f58b082a RW |
41 | }; |
42 | ||
43 | struct lpss_private_data { | |
44 | void __iomem *mmio_base; | |
45 | resource_size_t mmio_size; | |
46 | struct clk *clk; | |
47 | const struct lpss_device_desc *dev_desc; | |
48 | }; | |
49 | ||
50 | static struct lpss_device_desc lpt_dev_desc = { | |
51 | .clk_required = true, | |
52 | .clk_parent = "lpss_clk", | |
2e0f8822 RW |
53 | .prv_offset = 0x800, |
54 | .ltr_required = true, | |
55 | }; | |
56 | ||
57 | static struct lpss_device_desc lpt_sdio_dev_desc = { | |
58 | .prv_offset = 0x1000, | |
59 | .ltr_required = true, | |
f58b082a RW |
60 | }; |
61 | ||
62 | static const struct acpi_device_id acpi_lpss_device_ids[] = { | |
63 | /* Lynxpoint LPSS devices */ | |
64 | { "INT33C0", (unsigned long)&lpt_dev_desc }, | |
65 | { "INT33C1", (unsigned long)&lpt_dev_desc }, | |
66 | { "INT33C2", (unsigned long)&lpt_dev_desc }, | |
67 | { "INT33C3", (unsigned long)&lpt_dev_desc }, | |
68 | { "INT33C4", (unsigned long)&lpt_dev_desc }, | |
69 | { "INT33C5", (unsigned long)&lpt_dev_desc }, | |
2e0f8822 | 70 | { "INT33C6", (unsigned long)&lpt_sdio_dev_desc }, |
f58b082a RW |
71 | { "INT33C7", }, |
72 | ||
73 | { } | |
74 | }; | |
75 | ||
76 | static int is_memory(struct acpi_resource *res, void *not_used) | |
77 | { | |
78 | struct resource r; | |
79 | return !acpi_dev_resource_memory(res, &r); | |
80 | } | |
81 | ||
82 | /* LPSS main clock device. */ | |
83 | static struct platform_device *lpss_clk_dev; | |
84 | ||
85 | static inline void lpt_register_clock_device(void) | |
86 | { | |
87 | lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0); | |
88 | } | |
89 | ||
90 | static int register_device_clock(struct acpi_device *adev, | |
91 | struct lpss_private_data *pdata) | |
92 | { | |
93 | const struct lpss_device_desc *dev_desc = pdata->dev_desc; | |
94 | ||
95 | if (!lpss_clk_dev) | |
96 | lpt_register_clock_device(); | |
97 | ||
98 | if (!dev_desc->clk_parent || !pdata->mmio_base | |
2e0f8822 | 99 | || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE) |
f58b082a RW |
100 | return -ENODATA; |
101 | ||
102 | pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev), | |
103 | dev_desc->clk_parent, 0, | |
2e0f8822 | 104 | pdata->mmio_base + dev_desc->prv_offset, |
f58b082a RW |
105 | 0, 0, NULL); |
106 | if (IS_ERR(pdata->clk)) | |
107 | return PTR_ERR(pdata->clk); | |
108 | ||
109 | clk_register_clkdev(pdata->clk, NULL, dev_name(&adev->dev)); | |
110 | return 0; | |
111 | } | |
112 | ||
113 | static int acpi_lpss_create_device(struct acpi_device *adev, | |
114 | const struct acpi_device_id *id) | |
115 | { | |
116 | struct lpss_device_desc *dev_desc; | |
117 | struct lpss_private_data *pdata; | |
118 | struct resource_list_entry *rentry; | |
119 | struct list_head resource_list; | |
120 | int ret; | |
121 | ||
122 | dev_desc = (struct lpss_device_desc *)id->driver_data; | |
123 | if (!dev_desc) | |
124 | return acpi_create_platform_device(adev, id); | |
125 | ||
126 | pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); | |
127 | if (!pdata) | |
128 | return -ENOMEM; | |
129 | ||
130 | INIT_LIST_HEAD(&resource_list); | |
131 | ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL); | |
132 | if (ret < 0) | |
133 | goto err_out; | |
134 | ||
135 | list_for_each_entry(rentry, &resource_list, node) | |
136 | if (resource_type(&rentry->res) == IORESOURCE_MEM) { | |
137 | pdata->mmio_size = resource_size(&rentry->res); | |
138 | pdata->mmio_base = ioremap(rentry->res.start, | |
139 | pdata->mmio_size); | |
140 | pdata->dev_desc = dev_desc; | |
141 | break; | |
142 | } | |
143 | ||
144 | acpi_dev_free_resource_list(&resource_list); | |
145 | ||
146 | if (dev_desc->clk_required) { | |
147 | ret = register_device_clock(adev, pdata); | |
148 | if (ret) { | |
149 | /* | |
150 | * Skip the device, but don't terminate the namespace | |
151 | * scan. | |
152 | */ | |
cf8df962 AS |
153 | kfree(pdata); |
154 | return 0; | |
f58b082a RW |
155 | } |
156 | } | |
157 | ||
158 | adev->driver_data = pdata; | |
159 | ret = acpi_create_platform_device(adev, id); | |
160 | if (ret > 0) | |
161 | return ret; | |
162 | ||
163 | adev->driver_data = NULL; | |
164 | ||
165 | err_out: | |
166 | kfree(pdata); | |
167 | return ret; | |
168 | } | |
169 | ||
2e0f8822 RW |
170 | static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val) |
171 | { | |
172 | struct acpi_device *adev; | |
173 | struct lpss_private_data *pdata; | |
174 | unsigned long flags; | |
175 | int ret; | |
176 | ||
177 | ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev); | |
178 | if (WARN_ON(ret)) | |
179 | return ret; | |
180 | ||
181 | spin_lock_irqsave(&dev->power.lock, flags); | |
182 | if (pm_runtime_suspended(dev)) { | |
183 | ret = -EAGAIN; | |
184 | goto out; | |
185 | } | |
186 | pdata = acpi_driver_data(adev); | |
187 | if (WARN_ON(!pdata || !pdata->mmio_base)) { | |
188 | ret = -ENODEV; | |
189 | goto out; | |
190 | } | |
191 | *val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg); | |
192 | ||
193 | out: | |
194 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
195 | return ret; | |
196 | } | |
197 | ||
198 | static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr, | |
199 | char *buf) | |
200 | { | |
201 | u32 ltr_value = 0; | |
202 | unsigned int reg; | |
203 | int ret; | |
204 | ||
205 | reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR; | |
206 | ret = lpss_reg_read(dev, reg, <r_value); | |
207 | if (ret) | |
208 | return ret; | |
209 | ||
210 | return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value); | |
211 | } | |
212 | ||
213 | static ssize_t lpss_ltr_mode_show(struct device *dev, | |
214 | struct device_attribute *attr, char *buf) | |
215 | { | |
216 | u32 ltr_mode = 0; | |
217 | char *outstr; | |
218 | int ret; | |
219 | ||
220 | ret = lpss_reg_read(dev, LPSS_GENERAL, <r_mode); | |
221 | if (ret) | |
222 | return ret; | |
223 | ||
224 | outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto"; | |
225 | return sprintf(buf, "%s\n", outstr); | |
226 | } | |
227 | ||
228 | static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL); | |
229 | static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL); | |
230 | static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL); | |
231 | ||
232 | static struct attribute *lpss_attrs[] = { | |
233 | &dev_attr_auto_ltr.attr, | |
234 | &dev_attr_sw_ltr.attr, | |
235 | &dev_attr_ltr_mode.attr, | |
236 | NULL, | |
237 | }; | |
238 | ||
239 | static struct attribute_group lpss_attr_group = { | |
240 | .attrs = lpss_attrs, | |
241 | .name = "lpss_ltr", | |
242 | }; | |
243 | ||
244 | static int acpi_lpss_platform_notify(struct notifier_block *nb, | |
245 | unsigned long action, void *data) | |
246 | { | |
247 | struct platform_device *pdev = to_platform_device(data); | |
248 | struct lpss_private_data *pdata; | |
249 | struct acpi_device *adev; | |
250 | const struct acpi_device_id *id; | |
251 | int ret = 0; | |
252 | ||
253 | id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev); | |
254 | if (!id || !id->driver_data) | |
255 | return 0; | |
256 | ||
257 | if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev)) | |
258 | return 0; | |
259 | ||
260 | pdata = acpi_driver_data(adev); | |
261 | if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required) | |
262 | return 0; | |
263 | ||
264 | if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) { | |
265 | dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n"); | |
266 | return 0; | |
267 | } | |
268 | ||
269 | if (action == BUS_NOTIFY_ADD_DEVICE) | |
270 | ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group); | |
271 | else if (action == BUS_NOTIFY_DEL_DEVICE) | |
272 | sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group); | |
273 | ||
274 | return ret; | |
275 | } | |
276 | ||
277 | static struct notifier_block acpi_lpss_nb = { | |
278 | .notifier_call = acpi_lpss_platform_notify, | |
279 | }; | |
280 | ||
f58b082a RW |
281 | static struct acpi_scan_handler lpss_handler = { |
282 | .ids = acpi_lpss_device_ids, | |
283 | .attach = acpi_lpss_create_device, | |
284 | }; | |
285 | ||
286 | void __init acpi_lpss_init(void) | |
287 | { | |
2e0f8822 RW |
288 | if (!lpt_clk_init()) { |
289 | bus_register_notifier(&platform_bus_type, &acpi_lpss_nb); | |
f58b082a | 290 | acpi_scan_add_handler(&lpss_handler); |
2e0f8822 | 291 | } |
f58b082a | 292 | } |