1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * ACPI PCI Hot Plug Controller Driver
4  *
5  * Copyright (C) 1995,2001 Compaq Computer Corporation
6  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
7  * Copyright (C) 2001 IBM Corp.
8  * Copyright (C) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com)
9  * Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com)
10  * Copyright (C) 2002,2003 NEC Corporation
11  * Copyright (C) 2003-2005 Matthew Wilcox (willy@infradead.org)
12  * Copyright (C) 2003-2005 Hewlett Packard
13  *
14  * All rights reserved.
15  *
16  * Send feedback to <kristen.c.accardi@intel.com>
17  *
18  */
19 
20 #define pr_fmt(fmt) "acpiphp: " fmt
21 
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 
26 #include <linux/kernel.h>
27 #include <linux/pci.h>
28 #include <linux/pci-acpi.h>
29 #include <linux/pci_hotplug.h>
30 #include <linux/slab.h>
31 #include <linux/smp.h>
32 #include "acpiphp.h"
33 
34 /* name size which is used for entries in pcihpfs */
35 #define SLOT_NAME_SIZE  21              /* {_SUN} */
36 
37 bool acpiphp_disabled;
38 
39 /* local variables */
40 static struct acpiphp_attention_info *attention_info;
41 
42 #define DRIVER_VERSION	"0.5"
43 #define DRIVER_AUTHOR	"Greg Kroah-Hartman <gregkh@us.ibm.com>, Takayoshi Kochi <t-kochi@bq.jp.nec.com>, Matthew Wilcox <willy@infradead.org>"
44 #define DRIVER_DESC	"ACPI Hot Plug PCI Controller Driver"
45 
46 MODULE_AUTHOR(DRIVER_AUTHOR);
47 MODULE_DESCRIPTION(DRIVER_DESC);
48 MODULE_PARM_DESC(disable, "disable acpiphp driver");
49 module_param_named(disable, acpiphp_disabled, bool, 0444);
50 
51 static int enable_slot(struct hotplug_slot *slot);
52 static int disable_slot(struct hotplug_slot *slot);
53 static int set_attention_status(struct hotplug_slot *slot, u8 value);
54 static int get_power_status(struct hotplug_slot *slot, u8 *value);
55 static int get_attention_status(struct hotplug_slot *slot, u8 *value);
56 static int get_latch_status(struct hotplug_slot *slot, u8 *value);
57 static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
58 
59 static const struct hotplug_slot_ops acpi_hotplug_slot_ops = {
60 	.enable_slot		= enable_slot,
61 	.disable_slot		= disable_slot,
62 	.set_attention_status	= set_attention_status,
63 	.get_power_status	= get_power_status,
64 	.get_attention_status	= get_attention_status,
65 	.get_latch_status	= get_latch_status,
66 	.get_adapter_status	= get_adapter_status,
67 };
68 
69 /**
70  * acpiphp_register_attention - set attention LED callback
71  * @info: must be completely filled with LED callbacks
72  *
73  * Description: This is used to register a hardware specific ACPI
74  * driver that manipulates the attention LED.  All the fields in
75  * info must be set.
76  */
77 int acpiphp_register_attention(struct acpiphp_attention_info *info)
78 {
79 	int retval = -EINVAL;
80 
81 	if (info && info->owner && info->set_attn &&
82 			info->get_attn && !attention_info) {
83 		retval = 0;
84 		attention_info = info;
85 	}
86 	return retval;
87 }
88 EXPORT_SYMBOL_GPL(acpiphp_register_attention);
89 
90 
91 /**
92  * acpiphp_unregister_attention - unset attention LED callback
93  * @info: must match the pointer used to register
94  *
95  * Description: This is used to un-register a hardware specific acpi
96  * driver that manipulates the attention LED.  The pointer to the
97  * info struct must be the same as the one used to set it.
98  */
99 int acpiphp_unregister_attention(struct acpiphp_attention_info *info)
100 {
101 	int retval = -EINVAL;
102 
103 	if (info && attention_info == info) {
104 		attention_info = NULL;
105 		retval = 0;
106 	}
107 	return retval;
108 }
109 EXPORT_SYMBOL_GPL(acpiphp_unregister_attention);
110 
111 
112 /**
113  * enable_slot - power on and enable a slot
114  * @hotplug_slot: slot to enable
115  *
116  * Actual tasks are done in acpiphp_enable_slot()
117  */
118 static int enable_slot(struct hotplug_slot *hotplug_slot)
119 {
120 	struct slot *slot = to_slot(hotplug_slot);
121 
122 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
123 
124 	/* enable the specified slot */
125 	return acpiphp_enable_slot(slot->acpi_slot);
126 }
127 
128 
129 /**
130  * disable_slot - disable and power off a slot
131  * @hotplug_slot: slot to disable
132  *
133  * Actual tasks are done in acpiphp_disable_slot()
134  */
135 static int disable_slot(struct hotplug_slot *hotplug_slot)
136 {
137 	struct slot *slot = to_slot(hotplug_slot);
138 
139 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
140 
141 	/* disable the specified slot */
142 	return acpiphp_disable_slot(slot->acpi_slot);
143 }
144 
145 
146 /**
147  * set_attention_status - set attention LED
148  * @hotplug_slot: slot to set attention LED on
149  * @status: value to set attention LED to (0 or 1)
150  *
151  * attention status LED, so we use a callback that
152  * was registered with us.  This allows hardware specific
153  * ACPI implementations to blink the light for us.
154  */
155 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
156 {
157 	int retval = -ENODEV;
158 
159 	pr_debug("%s - physical_slot = %s\n", __func__,
160 		hotplug_slot_name(hotplug_slot));
161 
162 	if (attention_info && try_module_get(attention_info->owner)) {
163 		retval = attention_info->set_attn(hotplug_slot, status);
164 		module_put(attention_info->owner);
165 	} else
166 		attention_info = NULL;
167 	return retval;
168 }
169 
170 
171 /**
172  * get_power_status - get power status of a slot
173  * @hotplug_slot: slot to get status
174  * @value: pointer to store status
175  *
176  * Some platforms may not implement _STA method properly.
177  * In that case, the value returned may not be reliable.
178  */
179 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
180 {
181 	struct slot *slot = to_slot(hotplug_slot);
182 
183 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
184 
185 	*value = acpiphp_get_power_status(slot->acpi_slot);
186 
187 	return 0;
188 }
189 
190 
191 /**
192  * get_attention_status - get attention LED status
193  * @hotplug_slot: slot to get status from
194  * @value: returns with value of attention LED
195  *
196  * ACPI doesn't have known method to determine the state
197  * of the attention status LED, so we use a callback that
198  * was registered with us.  This allows hardware specific
199  * ACPI implementations to determine its state.
200  */
201 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
202 {
203 	int retval = -EINVAL;
204 
205 	pr_debug("%s - physical_slot = %s\n", __func__,
206 		hotplug_slot_name(hotplug_slot));
207 
208 	if (attention_info && try_module_get(attention_info->owner)) {
209 		retval = attention_info->get_attn(hotplug_slot, value);
210 		module_put(attention_info->owner);
211 	} else
212 		attention_info = NULL;
213 	return retval;
214 }
215 
216 
217 /**
218  * get_latch_status - get latch status of a slot
219  * @hotplug_slot: slot to get status
220  * @value: pointer to store status
221  *
222  * ACPI doesn't provide any formal means to access latch status.
223  * Instead, we fake latch status from _STA.
224  */
225 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
226 {
227 	struct slot *slot = to_slot(hotplug_slot);
228 
229 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
230 
231 	*value = acpiphp_get_latch_status(slot->acpi_slot);
232 
233 	return 0;
234 }
235 
236 
237 /**
238  * get_adapter_status - get adapter status of a slot
239  * @hotplug_slot: slot to get status
240  * @value: pointer to store status
241  *
242  * ACPI doesn't provide any formal means to access adapter status.
243  * Instead, we fake adapter status from _STA.
244  */
245 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
246 {
247 	struct slot *slot = to_slot(hotplug_slot);
248 
249 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
250 
251 	*value = acpiphp_get_adapter_status(slot->acpi_slot);
252 
253 	return 0;
254 }
255 
256 /* callback routine to initialize 'struct slot' for each slot */
257 int acpiphp_register_hotplug_slot(struct acpiphp_slot *acpiphp_slot,
258 				  unsigned int sun)
259 {
260 	struct slot *slot;
261 	int retval = -ENOMEM;
262 	char name[SLOT_NAME_SIZE];
263 
264 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
265 	if (!slot)
266 		goto error;
267 
268 	slot->hotplug_slot.ops = &acpi_hotplug_slot_ops;
269 
270 	slot->acpi_slot = acpiphp_slot;
271 
272 	acpiphp_slot->slot = slot;
273 	slot->sun = sun;
274 	snprintf(name, SLOT_NAME_SIZE, "%u", sun);
275 
276 	retval = pci_hp_register(&slot->hotplug_slot, acpiphp_slot->bus,
277 				 acpiphp_slot->device, name);
278 	if (retval == -EBUSY)
279 		goto error_slot;
280 	if (retval) {
281 		pr_err("pci_hp_register failed with error %d\n", retval);
282 		goto error_slot;
283 	}
284 
285 	pr_info("Slot [%s] registered\n", slot_name(slot));
286 
287 	return 0;
288 error_slot:
289 	kfree(slot);
290 error:
291 	return retval;
292 }
293 
294 
295 void acpiphp_unregister_hotplug_slot(struct acpiphp_slot *acpiphp_slot)
296 {
297 	struct slot *slot = acpiphp_slot->slot;
298 
299 	pr_info("Slot [%s] unregistered\n", slot_name(slot));
300 
301 	pci_hp_deregister(&slot->hotplug_slot);
302 	kfree(slot);
303 }
304 
305 
306 void __init acpiphp_init(void)
307 {
308 	pr_info(DRIVER_DESC " version: " DRIVER_VERSION "%s\n",
309 		acpiphp_disabled ? ", disabled by user; please report a bug"
310 				 : "");
311 }
312