xref: /openbmc/linux/drivers/pci/pci-acpi.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
1 /*
2  * File:	pci-acpi.c
3  * Purpose:	Provide PCI support in ACPI
4  *
5  * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
6  * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
7  * Copyright (C) 2004 Intel Corp.
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/init.h>
12 #include <linux/pci.h>
13 #include <linux/module.h>
14 #include <acpi/acpi.h>
15 #include <acpi/acnamesp.h>
16 #include <acpi/acresrc.h>
17 #include <acpi/acpi_bus.h>
18 
19 #include <linux/pci-acpi.h>
20 #include "pci.h"
21 
22 struct acpi_osc_data {
23 	acpi_handle handle;
24 	u32 support_set;
25 	u32 control_set;
26 	int is_queried;
27 	u32 query_result;
28 	struct list_head sibiling;
29 };
30 static LIST_HEAD(acpi_osc_data_list);
31 
32 struct acpi_osc_args {
33 	u32 capbuf[3];
34 	u32 query_result;
35 };
36 
37 static struct acpi_osc_data *acpi_get_osc_data(acpi_handle handle)
38 {
39 	struct acpi_osc_data *data;
40 
41 	list_for_each_entry(data, &acpi_osc_data_list, sibiling) {
42 		if (data->handle == handle)
43 			return data;
44 	}
45 	data = kzalloc(sizeof(*data), GFP_KERNEL);
46 	if (!data)
47 		return NULL;
48 	INIT_LIST_HEAD(&data->sibiling);
49 	data->handle = handle;
50 	list_add_tail(&data->sibiling, &acpi_osc_data_list);
51 	return data;
52 }
53 
54 static u8 OSC_UUID[16] = {0x5B, 0x4D, 0xDB, 0x33, 0xF7, 0x1F, 0x1C, 0x40,
55 			  0x96, 0x57, 0x74, 0x41, 0xC0, 0x3D, 0xD7, 0x66};
56 
57 static acpi_status acpi_run_osc(acpi_handle handle,
58 				struct acpi_osc_args *osc_args)
59 {
60 	acpi_status status;
61 	struct acpi_object_list input;
62 	union acpi_object in_params[4];
63 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
64 	union acpi_object *out_obj;
65 	u32 osc_dw0, flags = osc_args->capbuf[OSC_QUERY_TYPE];
66 
67 	/* Setting up input parameters */
68 	input.count = 4;
69 	input.pointer = in_params;
70 	in_params[0].type 		= ACPI_TYPE_BUFFER;
71 	in_params[0].buffer.length 	= 16;
72 	in_params[0].buffer.pointer	= OSC_UUID;
73 	in_params[1].type 		= ACPI_TYPE_INTEGER;
74 	in_params[1].integer.value 	= 1;
75 	in_params[2].type 		= ACPI_TYPE_INTEGER;
76 	in_params[2].integer.value	= 3;
77 	in_params[3].type		= ACPI_TYPE_BUFFER;
78 	in_params[3].buffer.length 	= 12;
79 	in_params[3].buffer.pointer 	= (u8 *)osc_args->capbuf;
80 
81 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
82 	if (ACPI_FAILURE(status))
83 		return status;
84 
85 	out_obj = output.pointer;
86 	if (out_obj->type != ACPI_TYPE_BUFFER) {
87 		printk(KERN_DEBUG "Evaluate _OSC returns wrong type\n");
88 		status = AE_TYPE;
89 		goto out_kfree;
90 	}
91 	osc_dw0 = *((u32 *)out_obj->buffer.pointer);
92 	if (osc_dw0) {
93 		if (osc_dw0 & OSC_REQUEST_ERROR)
94 			printk(KERN_DEBUG "_OSC request fails\n");
95 		if (osc_dw0 & OSC_INVALID_UUID_ERROR)
96 			printk(KERN_DEBUG "_OSC invalid UUID\n");
97 		if (osc_dw0 & OSC_INVALID_REVISION_ERROR)
98 			printk(KERN_DEBUG "_OSC invalid revision\n");
99 		if (osc_dw0 & OSC_CAPABILITIES_MASK_ERROR) {
100 			if (flags & OSC_QUERY_ENABLE)
101 				goto out_success;
102 			printk(KERN_DEBUG "_OSC FW not grant req. control\n");
103 			status = AE_SUPPORT;
104 			goto out_kfree;
105 		}
106 		status = AE_ERROR;
107 		goto out_kfree;
108 	}
109 out_success:
110 	if (flags & OSC_QUERY_ENABLE)
111 		osc_args->query_result =
112 			*((u32 *)(out_obj->buffer.pointer + 8));
113 	status = AE_OK;
114 
115 out_kfree:
116 	kfree(output.pointer);
117 	return status;
118 }
119 
120 static acpi_status acpi_query_osc(acpi_handle handle,
121 				  u32 level, void *context, void **retval)
122 {
123 	acpi_status status;
124 	struct acpi_osc_data *osc_data;
125 	u32 flags = (unsigned long)context, support_set;
126 	acpi_handle tmp;
127 	struct acpi_osc_args osc_args;
128 
129 	status = acpi_get_handle(handle, "_OSC", &tmp);
130 	if (ACPI_FAILURE(status))
131 		return status;
132 
133 	osc_data = acpi_get_osc_data(handle);
134 	if (!osc_data) {
135 		printk(KERN_ERR "acpi osc data array is full\n");
136 		return AE_ERROR;
137 	}
138 
139 	/* do _OSC query for all possible controls */
140 	support_set = osc_data->support_set | (flags & OSC_SUPPORT_MASKS);
141 	osc_args.capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
142 	osc_args.capbuf[OSC_SUPPORT_TYPE] = support_set;
143 	osc_args.capbuf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;
144 
145 	status = acpi_run_osc(handle, &osc_args);
146 	if (ACPI_SUCCESS(status)) {
147 		osc_data->support_set = support_set;
148 		osc_data->query_result = osc_args.query_result;
149 		osc_data->is_queried = 1;
150 	}
151 
152 	return status;
153 }
154 
155 /**
156  * __pci_osc_support_set - register OS support to Firmware
157  * @flags: OS support bits
158  * @hid: hardware ID
159  *
160  * Update OS support fields and doing a _OSC Query to obtain an update
161  * from Firmware on supported control bits.
162  **/
163 acpi_status __pci_osc_support_set(u32 flags, const char *hid)
164 {
165 	if (!(flags & OSC_SUPPORT_MASKS))
166 		return AE_TYPE;
167 
168 	acpi_get_devices(hid, acpi_query_osc,
169 			 (void *)(unsigned long)flags, NULL);
170 	return AE_OK;
171 }
172 
173 /**
174  * pci_osc_control_set - commit requested control to Firmware
175  * @handle: acpi_handle for the target ACPI object
176  * @flags: driver's requested control bits
177  *
178  * Attempt to take control from Firmware on requested control bits.
179  **/
180 acpi_status pci_osc_control_set(acpi_handle handle, u32 flags)
181 {
182 	acpi_status status;
183 	u32 ctrlset, control_set;
184 	acpi_handle tmp;
185 	struct acpi_osc_data *osc_data;
186 	struct acpi_osc_args osc_args;
187 
188 	status = acpi_get_handle(handle, "_OSC", &tmp);
189 	if (ACPI_FAILURE(status))
190 		return status;
191 
192 	osc_data = acpi_get_osc_data(handle);
193 	if (!osc_data) {
194 		printk(KERN_ERR "acpi osc data array is full\n");
195 		return AE_ERROR;
196 	}
197 
198 	ctrlset = (flags & OSC_CONTROL_MASKS);
199 	if (!ctrlset)
200 		return AE_TYPE;
201 
202 	if (osc_data->is_queried &&
203 	    ((osc_data->query_result & ctrlset) != ctrlset))
204 		return AE_SUPPORT;
205 
206 	control_set = osc_data->control_set | ctrlset;
207 	osc_args.capbuf[OSC_QUERY_TYPE] = 0;
208 	osc_args.capbuf[OSC_SUPPORT_TYPE] = osc_data->support_set;
209 	osc_args.capbuf[OSC_CONTROL_TYPE] = control_set;
210 	status = acpi_run_osc(handle, &osc_args);
211 	if (ACPI_SUCCESS(status))
212 		osc_data->control_set = control_set;
213 
214 	return status;
215 }
216 EXPORT_SYMBOL(pci_osc_control_set);
217 
218 /*
219  * _SxD returns the D-state with the highest power
220  * (lowest D-state number) supported in the S-state "x".
221  *
222  * If the devices does not have a _PRW
223  * (Power Resources for Wake) supporting system wakeup from "x"
224  * then the OS is free to choose a lower power (higher number
225  * D-state) than the return value from _SxD.
226  *
227  * But if _PRW is enabled at S-state "x", the OS
228  * must not choose a power lower than _SxD --
229  * unless the device has an _SxW method specifying
230  * the lowest power (highest D-state number) the device
231  * may enter while still able to wake the system.
232  *
233  * ie. depending on global OS policy:
234  *
235  * if (_PRW at S-state x)
236  *	choose from highest power _SxD to lowest power _SxW
237  * else // no _PRW at S-state x
238  * 	choose highest power _SxD or any lower power
239  */
240 
241 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
242 {
243 	int acpi_state;
244 
245 	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
246 	if (acpi_state < 0)
247 		return PCI_POWER_ERROR;
248 
249 	switch (acpi_state) {
250 	case ACPI_STATE_D0:
251 		return PCI_D0;
252 	case ACPI_STATE_D1:
253 		return PCI_D1;
254 	case ACPI_STATE_D2:
255 		return PCI_D2;
256 	case ACPI_STATE_D3:
257 		return PCI_D3hot;
258 	}
259 	return PCI_POWER_ERROR;
260 }
261 
262 static bool acpi_pci_power_manageable(struct pci_dev *dev)
263 {
264 	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
265 
266 	return handle ? acpi_bus_power_manageable(handle) : false;
267 }
268 
269 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
270 {
271 	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
272 	acpi_handle tmp;
273 	static const u8 state_conv[] = {
274 		[PCI_D0] = ACPI_STATE_D0,
275 		[PCI_D1] = ACPI_STATE_D1,
276 		[PCI_D2] = ACPI_STATE_D2,
277 		[PCI_D3hot] = ACPI_STATE_D3,
278 		[PCI_D3cold] = ACPI_STATE_D3
279 	};
280 	int error = -EINVAL;
281 
282 	/* If the ACPI device has _EJ0, ignore the device */
283 	if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
284 		return -ENODEV;
285 
286 	switch (state) {
287 	case PCI_D0:
288 	case PCI_D1:
289 	case PCI_D2:
290 	case PCI_D3hot:
291 	case PCI_D3cold:
292 		error = acpi_bus_set_power(handle, state_conv[state]);
293 	}
294 
295 	if (!error)
296 		dev_printk(KERN_INFO, &dev->dev,
297 				"power state changed by ACPI to D%d\n", state);
298 
299 	return error;
300 }
301 
302 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
303 {
304 	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
305 
306 	return handle ? acpi_bus_can_wakeup(handle) : false;
307 }
308 
309 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
310 {
311 	int error = acpi_pm_device_sleep_wake(&dev->dev, enable);
312 
313 	if (!error)
314 		dev_printk(KERN_INFO, &dev->dev,
315 				"wake-up capability %s by ACPI\n",
316 				enable ? "enabled" : "disabled");
317 	return error;
318 }
319 
320 static struct pci_platform_pm_ops acpi_pci_platform_pm = {
321 	.is_manageable = acpi_pci_power_manageable,
322 	.set_state = acpi_pci_set_power_state,
323 	.choose_state = acpi_pci_choose_state,
324 	.can_wakeup = acpi_pci_can_wakeup,
325 	.sleep_wake = acpi_pci_sleep_wake,
326 };
327 
328 /* ACPI bus type */
329 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
330 {
331 	struct pci_dev * pci_dev;
332 	acpi_integer	addr;
333 
334 	pci_dev = to_pci_dev(dev);
335 	/* Please ref to ACPI spec for the syntax of _ADR */
336 	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
337 	*handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
338 	if (!*handle)
339 		return -ENODEV;
340 	return 0;
341 }
342 
343 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
344 {
345 	int num;
346 	unsigned int seg, bus;
347 
348 	/*
349 	 * The string should be the same as root bridge's name
350 	 * Please look at 'pci_scan_bus_parented'
351 	 */
352 	num = sscanf(dev->bus_id, "pci%04x:%02x", &seg, &bus);
353 	if (num != 2)
354 		return -ENODEV;
355 	*handle = acpi_get_pci_rootbridge_handle(seg, bus);
356 	if (!*handle)
357 		return -ENODEV;
358 	return 0;
359 }
360 
361 static struct acpi_bus_type acpi_pci_bus = {
362 	.bus = &pci_bus_type,
363 	.find_device = acpi_pci_find_device,
364 	.find_bridge = acpi_pci_find_root_bridge,
365 };
366 
367 static int __init acpi_pci_init(void)
368 {
369 	int ret;
370 
371 	if (acpi_gbl_FADT.boot_flags & BAF_MSI_NOT_SUPPORTED) {
372 		printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
373 		pci_no_msi();
374 	}
375 	ret = register_acpi_bus_type(&acpi_pci_bus);
376 	if (ret)
377 		return 0;
378 	pci_set_platform_pm(&acpi_pci_platform_pm);
379 	return 0;
380 }
381 arch_initcall(acpi_pci_init);
382