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_LICENSE("GPL");
49 MODULE_PARM_DESC(disable, "disable acpiphp driver");
50 module_param_named(disable, acpiphp_disabled, bool, 0444);
51 
52 static int enable_slot(struct hotplug_slot *slot);
53 static int disable_slot(struct hotplug_slot *slot);
54 static int set_attention_status(struct hotplug_slot *slot, u8 value);
55 static int get_power_status(struct hotplug_slot *slot, u8 *value);
56 static int get_attention_status(struct hotplug_slot *slot, u8 *value);
57 static int get_latch_status(struct hotplug_slot *slot, u8 *value);
58 static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
59 
60 static const struct hotplug_slot_ops acpi_hotplug_slot_ops = {
61 	.enable_slot		= enable_slot,
62 	.disable_slot		= disable_slot,
63 	.set_attention_status	= set_attention_status,
64 	.get_power_status	= get_power_status,
65 	.get_attention_status	= get_attention_status,
66 	.get_latch_status	= get_latch_status,
67 	.get_adapter_status	= get_adapter_status,
68 };
69 
70 /**
71  * acpiphp_register_attention - set attention LED callback
72  * @info: must be completely filled with LED callbacks
73  *
74  * Description: This is used to register a hardware specific ACPI
75  * driver that manipulates the attention LED.  All the fields in
76  * info must be set.
77  */
78 int acpiphp_register_attention(struct acpiphp_attention_info *info)
79 {
80 	int retval = -EINVAL;
81 
82 	if (info && info->owner && info->set_attn &&
83 			info->get_attn && !attention_info) {
84 		retval = 0;
85 		attention_info = info;
86 	}
87 	return retval;
88 }
89 EXPORT_SYMBOL_GPL(acpiphp_register_attention);
90 
91 
92 /**
93  * acpiphp_unregister_attention - unset attention LED callback
94  * @info: must match the pointer used to register
95  *
96  * Description: This is used to un-register a hardware specific acpi
97  * driver that manipulates the attention LED.  The pointer to the
98  * info struct must be the same as the one used to set it.
99  */
100 int acpiphp_unregister_attention(struct acpiphp_attention_info *info)
101 {
102 	int retval = -EINVAL;
103 
104 	if (info && attention_info == info) {
105 		attention_info = NULL;
106 		retval = 0;
107 	}
108 	return retval;
109 }
110 EXPORT_SYMBOL_GPL(acpiphp_unregister_attention);
111 
112 
113 /**
114  * enable_slot - power on and enable a slot
115  * @hotplug_slot: slot to enable
116  *
117  * Actual tasks are done in acpiphp_enable_slot()
118  */
119 static int enable_slot(struct hotplug_slot *hotplug_slot)
120 {
121 	struct slot *slot = to_slot(hotplug_slot);
122 
123 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
124 
125 	/* enable the specified slot */
126 	return acpiphp_enable_slot(slot->acpi_slot);
127 }
128 
129 
130 /**
131  * disable_slot - disable and power off a slot
132  * @hotplug_slot: slot to disable
133  *
134  * Actual tasks are done in acpiphp_disable_slot()
135  */
136 static int disable_slot(struct hotplug_slot *hotplug_slot)
137 {
138 	struct slot *slot = to_slot(hotplug_slot);
139 
140 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
141 
142 	/* disable the specified slot */
143 	return acpiphp_disable_slot(slot->acpi_slot);
144 }
145 
146 
147 /**
148  * set_attention_status - set attention LED
149  * @hotplug_slot: slot to set attention LED on
150  * @status: value to set attention LED to (0 or 1)
151  *
152  * attention status LED, so we use a callback that
153  * was registered with us.  This allows hardware specific
154  * ACPI implementations to blink the light for us.
155  */
156 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
157 {
158 	int retval = -ENODEV;
159 
160 	pr_debug("%s - physical_slot = %s\n", __func__,
161 		hotplug_slot_name(hotplug_slot));
162 
163 	if (attention_info && try_module_get(attention_info->owner)) {
164 		retval = attention_info->set_attn(hotplug_slot, status);
165 		module_put(attention_info->owner);
166 	} else
167 		attention_info = NULL;
168 	return retval;
169 }
170 
171 
172 /**
173  * get_power_status - get power status of a slot
174  * @hotplug_slot: slot to get status
175  * @value: pointer to store status
176  *
177  * Some platforms may not implement _STA method properly.
178  * In that case, the value returned may not be reliable.
179  */
180 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
181 {
182 	struct slot *slot = to_slot(hotplug_slot);
183 
184 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
185 
186 	*value = acpiphp_get_power_status(slot->acpi_slot);
187 
188 	return 0;
189 }
190 
191 
192 /**
193  * get_attention_status - get attention LED status
194  * @hotplug_slot: slot to get status from
195  * @value: returns with value of attention LED
196  *
197  * ACPI doesn't have known method to determine the state
198  * of the attention status LED, so we use a callback that
199  * was registered with us.  This allows hardware specific
200  * ACPI implementations to determine its state.
201  */
202 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
203 {
204 	int retval = -EINVAL;
205 
206 	pr_debug("%s - physical_slot = %s\n", __func__,
207 		hotplug_slot_name(hotplug_slot));
208 
209 	if (attention_info && try_module_get(attention_info->owner)) {
210 		retval = attention_info->get_attn(hotplug_slot, value);
211 		module_put(attention_info->owner);
212 	} else
213 		attention_info = NULL;
214 	return retval;
215 }
216 
217 
218 /**
219  * get_latch_status - get latch status of a slot
220  * @hotplug_slot: slot to get status
221  * @value: pointer to store status
222  *
223  * ACPI doesn't provide any formal means to access latch status.
224  * Instead, we fake latch status from _STA.
225  */
226 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
227 {
228 	struct slot *slot = to_slot(hotplug_slot);
229 
230 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
231 
232 	*value = acpiphp_get_latch_status(slot->acpi_slot);
233 
234 	return 0;
235 }
236 
237 
238 /**
239  * get_adapter_status - get adapter status of a slot
240  * @hotplug_slot: slot to get status
241  * @value: pointer to store status
242  *
243  * ACPI doesn't provide any formal means to access adapter status.
244  * Instead, we fake adapter status from _STA.
245  */
246 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
247 {
248 	struct slot *slot = to_slot(hotplug_slot);
249 
250 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
251 
252 	*value = acpiphp_get_adapter_status(slot->acpi_slot);
253 
254 	return 0;
255 }
256 
257 /* callback routine to initialize 'struct slot' for each slot */
258 int acpiphp_register_hotplug_slot(struct acpiphp_slot *acpiphp_slot,
259 				  unsigned int sun)
260 {
261 	struct slot *slot;
262 	int retval = -ENOMEM;
263 	char name[SLOT_NAME_SIZE];
264 
265 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
266 	if (!slot)
267 		goto error;
268 
269 	slot->hotplug_slot.ops = &acpi_hotplug_slot_ops;
270 
271 	slot->acpi_slot = acpiphp_slot;
272 
273 	acpiphp_slot->slot = slot;
274 	slot->sun = sun;
275 	snprintf(name, SLOT_NAME_SIZE, "%u", sun);
276 
277 	retval = pci_hp_register(&slot->hotplug_slot, acpiphp_slot->bus,
278 				 acpiphp_slot->device, name);
279 	if (retval == -EBUSY)
280 		goto error_slot;
281 	if (retval) {
282 		pr_err("pci_hp_register failed with error %d\n", retval);
283 		goto error_slot;
284 	}
285 
286 	pr_info("Slot [%s] registered\n", slot_name(slot));
287 
288 	return 0;
289 error_slot:
290 	kfree(slot);
291 error:
292 	return retval;
293 }
294 
295 
296 void acpiphp_unregister_hotplug_slot(struct acpiphp_slot *acpiphp_slot)
297 {
298 	struct slot *slot = acpiphp_slot->slot;
299 
300 	pr_info("Slot [%s] unregistered\n", slot_name(slot));
301 
302 	pci_hp_deregister(&slot->hotplug_slot);
303 	kfree(slot);
304 }
305 
306 
307 void __init acpiphp_init(void)
308 {
309 	pr_info(DRIVER_DESC " version: " DRIVER_VERSION "%s\n",
310 		acpiphp_disabled ? ", disabled by user; please report a bug"
311 				 : "");
312 }
313