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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> | |
31 | ||
32 | #include <asm/of_device.h> | |
33 | #include <asm/of_platform.h> | |
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 | ||
51 | ||
0e826643 CK |
52 | static int pmi_irq_handler(int irq, void *dev_id) |
53 | { | |
54 | struct pmi_data *data; | |
55 | u8 type; | |
56 | int rc; | |
57 | ||
58 | data = dev_id; | |
59 | ||
60 | spin_lock(&data->pmi_spinlock); | |
61 | ||
62 | type = ioread8(data->pmi_reg + PMI_READ_TYPE); | |
63 | pr_debug("pmi: got message of type %d\n", type); | |
64 | ||
65 | if (type & PMI_ACK && !data->completion) { | |
66 | printk(KERN_WARNING "pmi: got unexpected ACK message.\n"); | |
67 | rc = -EIO; | |
68 | goto unlock; | |
69 | } | |
70 | ||
71 | if (data->completion && !(type & PMI_ACK)) { | |
72 | printk(KERN_WARNING "pmi: expected ACK, but got %d\n", type); | |
73 | rc = -EIO; | |
74 | goto unlock; | |
75 | } | |
76 | ||
77 | data->msg.type = type; | |
78 | data->msg.data0 = ioread8(data->pmi_reg + PMI_READ_DATA0); | |
79 | data->msg.data1 = ioread8(data->pmi_reg + PMI_READ_DATA1); | |
80 | data->msg.data2 = ioread8(data->pmi_reg + PMI_READ_DATA2); | |
81 | rc = 0; | |
82 | unlock: | |
83 | spin_unlock(&data->pmi_spinlock); | |
84 | ||
85 | if (rc == -EIO) { | |
86 | rc = IRQ_HANDLED; | |
87 | goto out; | |
88 | } | |
89 | ||
90 | if (data->msg.type & PMI_ACK) { | |
91 | complete(data->completion); | |
92 | rc = IRQ_HANDLED; | |
93 | goto out; | |
94 | } | |
95 | ||
96 | schedule_work(&data->work); | |
97 | ||
98 | rc = IRQ_HANDLED; | |
99 | out: | |
100 | return rc; | |
101 | } | |
102 | ||
103 | ||
104 | static struct of_device_id pmi_match[] = { | |
105 | { .type = "ibm,pmi", .name = "ibm,pmi" }, | |
4a065f94 | 106 | { .type = "ibm,pmi" }, |
0e826643 CK |
107 | {}, |
108 | }; | |
109 | ||
110 | MODULE_DEVICE_TABLE(of, pmi_match); | |
111 | ||
112 | static void pmi_notify_handlers(struct work_struct *work) | |
113 | { | |
114 | struct pmi_data *data; | |
115 | struct pmi_handler *handler; | |
116 | ||
117 | data = container_of(work, struct pmi_data, work); | |
118 | ||
119 | spin_lock(&data->handler_spinlock); | |
120 | list_for_each_entry(handler, &data->handler, node) { | |
121 | pr_debug(KERN_INFO "pmi: notifying handler %p\n", handler); | |
122 | if (handler->type == data->msg.type) | |
123 | handler->handle_pmi_message(data->dev, data->msg); | |
124 | } | |
125 | spin_unlock(&data->handler_spinlock); | |
126 | } | |
127 | ||
128 | static int pmi_of_probe(struct of_device *dev, | |
129 | const struct of_device_id *match) | |
130 | { | |
131 | struct device_node *np = dev->node; | |
132 | struct pmi_data *data; | |
133 | int rc; | |
134 | ||
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 | ||
157 | dev->dev.driver_data = data; | |
158 | data->dev = dev; | |
159 | ||
160 | data->irq = irq_of_parse_and_map(np, 0); | |
161 | if (data->irq == NO_IRQ) { | |
162 | printk(KERN_ERR "pmi: invalid interrupt.\n"); | |
163 | rc = -EFAULT; | |
164 | goto error_cleanup_iomap; | |
165 | } | |
166 | ||
167 | rc = request_irq(data->irq, pmi_irq_handler, 0, "pmi", data); | |
168 | if (rc) { | |
169 | printk(KERN_ERR "pmi: can't request IRQ %d: returned %d\n", | |
170 | data->irq, rc); | |
171 | goto error_cleanup_iomap; | |
172 | } | |
173 | ||
174 | printk(KERN_INFO "pmi: found pmi device at addr %p.\n", data->pmi_reg); | |
175 | ||
176 | goto out; | |
177 | ||
178 | error_cleanup_iomap: | |
179 | iounmap(data->pmi_reg); | |
180 | ||
181 | error_cleanup_data: | |
182 | kfree(data); | |
183 | ||
184 | out: | |
185 | return rc; | |
186 | } | |
187 | ||
188 | static int pmi_of_remove(struct of_device *dev) | |
189 | { | |
190 | struct pmi_data *data; | |
191 | struct pmi_handler *handler, *tmp; | |
192 | ||
193 | data = dev->dev.driver_data; | |
194 | ||
195 | free_irq(data->irq, data); | |
196 | iounmap(data->pmi_reg); | |
197 | ||
198 | spin_lock(&data->handler_spinlock); | |
199 | ||
200 | list_for_each_entry_safe(handler, tmp, &data->handler, node) | |
201 | list_del(&handler->node); | |
202 | ||
203 | spin_unlock(&data->handler_spinlock); | |
204 | ||
205 | kfree(dev->dev.driver_data); | |
206 | ||
207 | return 0; | |
208 | } | |
209 | ||
210 | static struct of_platform_driver pmi_of_platform_driver = { | |
211 | .name = "pmi", | |
212 | .match_table = pmi_match, | |
213 | .probe = pmi_of_probe, | |
214 | .remove = pmi_of_remove | |
215 | }; | |
216 | ||
217 | static int __init pmi_module_init(void) | |
218 | { | |
219 | return of_register_platform_driver(&pmi_of_platform_driver); | |
220 | } | |
221 | module_init(pmi_module_init); | |
222 | ||
223 | static void __exit pmi_module_exit(void) | |
224 | { | |
225 | of_unregister_platform_driver(&pmi_of_platform_driver); | |
226 | } | |
227 | module_exit(pmi_module_exit); | |
228 | ||
229 | void pmi_send_message(struct of_device *device, pmi_message_t msg) | |
230 | { | |
231 | struct pmi_data *data; | |
232 | unsigned long flags; | |
233 | DECLARE_COMPLETION_ONSTACK(completion); | |
234 | ||
235 | data = device->dev.driver_data; | |
236 | ||
237 | mutex_lock(&data->msg_mutex); | |
238 | ||
239 | data->msg = msg; | |
240 | pr_debug("pmi_send_message: msg is %08x\n", *(u32*)&msg); | |
241 | ||
242 | data->completion = &completion; | |
243 | ||
244 | spin_lock_irqsave(&data->pmi_spinlock, flags); | |
245 | iowrite8(msg.data0, data->pmi_reg + PMI_WRITE_DATA0); | |
246 | iowrite8(msg.data1, data->pmi_reg + PMI_WRITE_DATA1); | |
247 | iowrite8(msg.data2, data->pmi_reg + PMI_WRITE_DATA2); | |
248 | iowrite8(msg.type, data->pmi_reg + PMI_WRITE_TYPE); | |
249 | spin_unlock_irqrestore(&data->pmi_spinlock, flags); | |
250 | ||
251 | pr_debug("pmi_send_message: wait for completion\n"); | |
252 | ||
253 | wait_for_completion_interruptible_timeout(data->completion, | |
254 | PMI_TIMEOUT); | |
255 | ||
256 | data->completion = NULL; | |
257 | ||
258 | mutex_unlock(&data->msg_mutex); | |
259 | } | |
260 | EXPORT_SYMBOL_GPL(pmi_send_message); | |
261 | ||
262 | void pmi_register_handler(struct of_device *device, | |
263 | struct pmi_handler *handler) | |
264 | { | |
265 | struct pmi_data *data; | |
266 | data = device->dev.driver_data; | |
267 | ||
79baf4a6 CK |
268 | if (!data) |
269 | return; | |
270 | ||
0e826643 CK |
271 | spin_lock(&data->handler_spinlock); |
272 | list_add_tail(&handler->node, &data->handler); | |
273 | spin_unlock(&data->handler_spinlock); | |
274 | } | |
275 | EXPORT_SYMBOL_GPL(pmi_register_handler); | |
276 | ||
277 | void pmi_unregister_handler(struct of_device *device, | |
278 | struct pmi_handler *handler) | |
279 | { | |
280 | struct pmi_data *data; | |
79baf4a6 | 281 | data = device->dev.driver_data; |
0e826643 | 282 | |
79baf4a6 CK |
283 | if (!data) |
284 | return; | |
0e826643 | 285 | |
79baf4a6 | 286 | pr_debug("pmi: unregistering handler %p\n", handler); |
0e826643 CK |
287 | |
288 | spin_lock(&data->handler_spinlock); | |
289 | list_del(&handler->node); | |
290 | spin_unlock(&data->handler_spinlock); | |
291 | } | |
292 | EXPORT_SYMBOL_GPL(pmi_unregister_handler); | |
293 | ||
294 | MODULE_LICENSE("GPL"); | |
295 | MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>"); | |
296 | MODULE_DESCRIPTION("IBM Platform Management Interrupt driver"); |