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0e826643 CK |
1 | /* |
2 | * pmi driver | |
3 | * | |
4 | * (C) Copyright IBM Deutschland Entwicklung GmbH 2005 | |
5 | * | |
6 | * PMI (Platform Management Interrupt) is a way to communicate | |
7 | * with the BMC (Baseboard Management Controller) via interrupts. | |
8 | * Unlike IPMI it is bidirectional and has a low latency. | |
9 | * | |
10 | * Author: Christian Krafft <krafft@de.ibm.com> | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2, or (at your option) | |
15 | * any later version. | |
16 | * | |
17 | * This program is distributed in the hope that it will be useful, | |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | * GNU General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License | |
23 | * along with this program; if not, write to the Free Software | |
24 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
25 | */ | |
26 | ||
27 | #include <linux/interrupt.h> | |
28 | #include <linux/completion.h> | |
29 | #include <linux/spinlock.h> | |
30 | #include <linux/workqueue.h> | |
eb8f2763 JL |
31 | #include <linux/of_device.h> |
32 | #include <linux/of_platform.h> | |
0e826643 | 33 | |
0e826643 CK |
34 | #include <asm/io.h> |
35 | #include <asm/pmi.h> | |
6bf05fd7 | 36 | #include <asm/prom.h> |
0e826643 CK |
37 | |
38 | struct pmi_data { | |
39 | struct list_head handler; | |
40 | spinlock_t handler_spinlock; | |
41 | spinlock_t pmi_spinlock; | |
42 | struct mutex msg_mutex; | |
43 | pmi_message_t msg; | |
44 | struct completion *completion; | |
45 | struct of_device *dev; | |
46 | int irq; | |
47 | u8 __iomem *pmi_reg; | |
48 | struct work_struct work; | |
49 | }; | |
50 | ||
813f9072 | 51 | static struct pmi_data *data; |
0e826643 | 52 | |
0e826643 CK |
53 | static int pmi_irq_handler(int irq, void *dev_id) |
54 | { | |
0e826643 CK |
55 | u8 type; |
56 | int rc; | |
57 | ||
0e826643 CK |
58 | spin_lock(&data->pmi_spinlock); |
59 | ||
60 | type = ioread8(data->pmi_reg + PMI_READ_TYPE); | |
61 | pr_debug("pmi: got message of type %d\n", type); | |
62 | ||
63 | if (type & PMI_ACK && !data->completion) { | |
64 | printk(KERN_WARNING "pmi: got unexpected ACK message.\n"); | |
65 | rc = -EIO; | |
66 | goto unlock; | |
67 | } | |
68 | ||
69 | if (data->completion && !(type & PMI_ACK)) { | |
70 | printk(KERN_WARNING "pmi: expected ACK, but got %d\n", type); | |
71 | rc = -EIO; | |
72 | goto unlock; | |
73 | } | |
74 | ||
75 | data->msg.type = type; | |
76 | data->msg.data0 = ioread8(data->pmi_reg + PMI_READ_DATA0); | |
77 | data->msg.data1 = ioread8(data->pmi_reg + PMI_READ_DATA1); | |
78 | data->msg.data2 = ioread8(data->pmi_reg + PMI_READ_DATA2); | |
79 | rc = 0; | |
80 | unlock: | |
81 | spin_unlock(&data->pmi_spinlock); | |
82 | ||
83 | if (rc == -EIO) { | |
84 | rc = IRQ_HANDLED; | |
85 | goto out; | |
86 | } | |
87 | ||
88 | if (data->msg.type & PMI_ACK) { | |
89 | complete(data->completion); | |
90 | rc = IRQ_HANDLED; | |
91 | goto out; | |
92 | } | |
93 | ||
94 | schedule_work(&data->work); | |
95 | ||
96 | rc = IRQ_HANDLED; | |
97 | out: | |
98 | return rc; | |
99 | } | |
100 | ||
101 | ||
102 | static struct of_device_id pmi_match[] = { | |
103 | { .type = "ibm,pmi", .name = "ibm,pmi" }, | |
4a065f94 | 104 | { .type = "ibm,pmi" }, |
0e826643 CK |
105 | {}, |
106 | }; | |
107 | ||
108 | MODULE_DEVICE_TABLE(of, pmi_match); | |
109 | ||
110 | static void pmi_notify_handlers(struct work_struct *work) | |
111 | { | |
0e826643 CK |
112 | struct pmi_handler *handler; |
113 | ||
0e826643 CK |
114 | spin_lock(&data->handler_spinlock); |
115 | list_for_each_entry(handler, &data->handler, node) { | |
116 | pr_debug(KERN_INFO "pmi: notifying handler %p\n", handler); | |
117 | if (handler->type == data->msg.type) | |
813f9072 | 118 | handler->handle_pmi_message(data->msg); |
0e826643 CK |
119 | } |
120 | spin_unlock(&data->handler_spinlock); | |
121 | } | |
122 | ||
123 | static int pmi_of_probe(struct of_device *dev, | |
124 | const struct of_device_id *match) | |
125 | { | |
126 | struct device_node *np = dev->node; | |
0e826643 CK |
127 | int rc; |
128 | ||
813f9072 CK |
129 | if (data) { |
130 | printk(KERN_ERR "pmi: driver has already been initialized.\n"); | |
131 | rc = -EBUSY; | |
132 | goto out; | |
133 | } | |
134 | ||
0e826643 CK |
135 | data = kzalloc(sizeof(struct pmi_data), GFP_KERNEL); |
136 | if (!data) { | |
137 | printk(KERN_ERR "pmi: could not allocate memory.\n"); | |
138 | rc = -ENOMEM; | |
139 | goto out; | |
140 | } | |
141 | ||
6bf05fd7 | 142 | data->pmi_reg = of_iomap(np, 0); |
0e826643 CK |
143 | if (!data->pmi_reg) { |
144 | printk(KERN_ERR "pmi: invalid register address.\n"); | |
145 | rc = -EFAULT; | |
146 | goto error_cleanup_data; | |
147 | } | |
148 | ||
149 | INIT_LIST_HEAD(&data->handler); | |
150 | ||
151 | mutex_init(&data->msg_mutex); | |
152 | spin_lock_init(&data->pmi_spinlock); | |
153 | spin_lock_init(&data->handler_spinlock); | |
154 | ||
155 | INIT_WORK(&data->work, pmi_notify_handlers); | |
156 | ||
0e826643 CK |
157 | data->dev = dev; |
158 | ||
159 | data->irq = irq_of_parse_and_map(np, 0); | |
160 | if (data->irq == NO_IRQ) { | |
161 | printk(KERN_ERR "pmi: invalid interrupt.\n"); | |
162 | rc = -EFAULT; | |
163 | goto error_cleanup_iomap; | |
164 | } | |
165 | ||
813f9072 | 166 | rc = request_irq(data->irq, pmi_irq_handler, 0, "pmi", NULL); |
0e826643 CK |
167 | if (rc) { |
168 | printk(KERN_ERR "pmi: can't request IRQ %d: returned %d\n", | |
169 | data->irq, rc); | |
170 | goto error_cleanup_iomap; | |
171 | } | |
172 | ||
173 | printk(KERN_INFO "pmi: found pmi device at addr %p.\n", data->pmi_reg); | |
174 | ||
175 | goto out; | |
176 | ||
177 | error_cleanup_iomap: | |
178 | iounmap(data->pmi_reg); | |
179 | ||
180 | error_cleanup_data: | |
181 | kfree(data); | |
182 | ||
183 | out: | |
184 | return rc; | |
185 | } | |
186 | ||
187 | static int pmi_of_remove(struct of_device *dev) | |
188 | { | |
0e826643 CK |
189 | struct pmi_handler *handler, *tmp; |
190 | ||
813f9072 | 191 | free_irq(data->irq, NULL); |
0e826643 CK |
192 | iounmap(data->pmi_reg); |
193 | ||
194 | spin_lock(&data->handler_spinlock); | |
195 | ||
196 | list_for_each_entry_safe(handler, tmp, &data->handler, node) | |
197 | list_del(&handler->node); | |
198 | ||
199 | spin_unlock(&data->handler_spinlock); | |
200 | ||
813f9072 CK |
201 | kfree(data); |
202 | data = NULL; | |
0e826643 CK |
203 | |
204 | return 0; | |
205 | } | |
206 | ||
207 | static struct of_platform_driver pmi_of_platform_driver = { | |
0e826643 CK |
208 | .match_table = pmi_match, |
209 | .probe = pmi_of_probe, | |
84dd4676 SR |
210 | .remove = pmi_of_remove, |
211 | .driver = { | |
212 | .name = "pmi", | |
213 | }, | |
0e826643 CK |
214 | }; |
215 | ||
216 | static int __init pmi_module_init(void) | |
217 | { | |
218 | return of_register_platform_driver(&pmi_of_platform_driver); | |
219 | } | |
220 | module_init(pmi_module_init); | |
221 | ||
222 | static void __exit pmi_module_exit(void) | |
223 | { | |
224 | of_unregister_platform_driver(&pmi_of_platform_driver); | |
225 | } | |
226 | module_exit(pmi_module_exit); | |
227 | ||
813f9072 | 228 | int pmi_send_message(pmi_message_t msg) |
0e826643 | 229 | { |
0e826643 CK |
230 | unsigned long flags; |
231 | DECLARE_COMPLETION_ONSTACK(completion); | |
232 | ||
813f9072 CK |
233 | if (!data) |
234 | return -ENODEV; | |
0e826643 CK |
235 | |
236 | mutex_lock(&data->msg_mutex); | |
237 | ||
238 | data->msg = msg; | |
239 | pr_debug("pmi_send_message: msg is %08x\n", *(u32*)&msg); | |
240 | ||
241 | data->completion = &completion; | |
242 | ||
243 | spin_lock_irqsave(&data->pmi_spinlock, flags); | |
244 | iowrite8(msg.data0, data->pmi_reg + PMI_WRITE_DATA0); | |
245 | iowrite8(msg.data1, data->pmi_reg + PMI_WRITE_DATA1); | |
246 | iowrite8(msg.data2, data->pmi_reg + PMI_WRITE_DATA2); | |
247 | iowrite8(msg.type, data->pmi_reg + PMI_WRITE_TYPE); | |
248 | spin_unlock_irqrestore(&data->pmi_spinlock, flags); | |
249 | ||
250 | pr_debug("pmi_send_message: wait for completion\n"); | |
251 | ||
252 | wait_for_completion_interruptible_timeout(data->completion, | |
253 | PMI_TIMEOUT); | |
254 | ||
255 | data->completion = NULL; | |
256 | ||
257 | mutex_unlock(&data->msg_mutex); | |
813f9072 CK |
258 | |
259 | return 0; | |
0e826643 CK |
260 | } |
261 | EXPORT_SYMBOL_GPL(pmi_send_message); | |
262 | ||
813f9072 | 263 | int pmi_register_handler(struct pmi_handler *handler) |
0e826643 | 264 | { |
79baf4a6 | 265 | if (!data) |
813f9072 | 266 | return -ENODEV; |
79baf4a6 | 267 | |
0e826643 CK |
268 | spin_lock(&data->handler_spinlock); |
269 | list_add_tail(&handler->node, &data->handler); | |
270 | spin_unlock(&data->handler_spinlock); | |
813f9072 CK |
271 | |
272 | return 0; | |
0e826643 CK |
273 | } |
274 | EXPORT_SYMBOL_GPL(pmi_register_handler); | |
275 | ||
813f9072 | 276 | void pmi_unregister_handler(struct pmi_handler *handler) |
0e826643 | 277 | { |
79baf4a6 CK |
278 | if (!data) |
279 | return; | |
0e826643 | 280 | |
79baf4a6 | 281 | pr_debug("pmi: unregistering handler %p\n", handler); |
0e826643 CK |
282 | |
283 | spin_lock(&data->handler_spinlock); | |
284 | list_del(&handler->node); | |
285 | spin_unlock(&data->handler_spinlock); | |
286 | } | |
287 | EXPORT_SYMBOL_GPL(pmi_unregister_handler); | |
288 | ||
289 | MODULE_LICENSE("GPL"); | |
290 | MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>"); | |
291 | MODULE_DESCRIPTION("IBM Platform Management Interrupt driver"); |