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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> | |
5a0e3ad6 | 28 | #include <linux/slab.h> |
0e826643 CK |
29 | #include <linux/completion.h> |
30 | #include <linux/spinlock.h> | |
31 | #include <linux/workqueue.h> | |
eb8f2763 JL |
32 | #include <linux/of_device.h> |
33 | #include <linux/of_platform.h> | |
0e826643 | 34 | |
0e826643 CK |
35 | #include <asm/io.h> |
36 | #include <asm/pmi.h> | |
6bf05fd7 | 37 | #include <asm/prom.h> |
0e826643 CK |
38 | |
39 | struct pmi_data { | |
40 | struct list_head handler; | |
41 | spinlock_t handler_spinlock; | |
42 | spinlock_t pmi_spinlock; | |
43 | struct mutex msg_mutex; | |
44 | pmi_message_t msg; | |
45 | struct completion *completion; | |
46 | struct of_device *dev; | |
47 | int irq; | |
48 | u8 __iomem *pmi_reg; | |
49 | struct work_struct work; | |
50 | }; | |
51 | ||
813f9072 | 52 | static struct pmi_data *data; |
0e826643 | 53 | |
fb247449 | 54 | static irqreturn_t pmi_irq_handler(int irq, void *dev_id) |
0e826643 | 55 | { |
0e826643 CK |
56 | u8 type; |
57 | int rc; | |
58 | ||
0e826643 CK |
59 | spin_lock(&data->pmi_spinlock); |
60 | ||
61 | type = ioread8(data->pmi_reg + PMI_READ_TYPE); | |
62 | pr_debug("pmi: got message of type %d\n", type); | |
63 | ||
64 | if (type & PMI_ACK && !data->completion) { | |
65 | printk(KERN_WARNING "pmi: got unexpected ACK message.\n"); | |
66 | rc = -EIO; | |
67 | goto unlock; | |
68 | } | |
69 | ||
70 | if (data->completion && !(type & PMI_ACK)) { | |
71 | printk(KERN_WARNING "pmi: expected ACK, but got %d\n", type); | |
72 | rc = -EIO; | |
73 | goto unlock; | |
74 | } | |
75 | ||
76 | data->msg.type = type; | |
77 | data->msg.data0 = ioread8(data->pmi_reg + PMI_READ_DATA0); | |
78 | data->msg.data1 = ioread8(data->pmi_reg + PMI_READ_DATA1); | |
79 | data->msg.data2 = ioread8(data->pmi_reg + PMI_READ_DATA2); | |
80 | rc = 0; | |
81 | unlock: | |
82 | spin_unlock(&data->pmi_spinlock); | |
83 | ||
84 | if (rc == -EIO) { | |
85 | rc = IRQ_HANDLED; | |
86 | goto out; | |
87 | } | |
88 | ||
89 | if (data->msg.type & PMI_ACK) { | |
90 | complete(data->completion); | |
91 | rc = IRQ_HANDLED; | |
92 | goto out; | |
93 | } | |
94 | ||
95 | schedule_work(&data->work); | |
96 | ||
97 | rc = IRQ_HANDLED; | |
98 | out: | |
99 | return rc; | |
100 | } | |
101 | ||
102 | ||
103 | static struct of_device_id pmi_match[] = { | |
104 | { .type = "ibm,pmi", .name = "ibm,pmi" }, | |
4a065f94 | 105 | { .type = "ibm,pmi" }, |
0e826643 CK |
106 | {}, |
107 | }; | |
108 | ||
109 | MODULE_DEVICE_TABLE(of, pmi_match); | |
110 | ||
111 | static void pmi_notify_handlers(struct work_struct *work) | |
112 | { | |
0e826643 CK |
113 | struct pmi_handler *handler; |
114 | ||
0e826643 CK |
115 | spin_lock(&data->handler_spinlock); |
116 | list_for_each_entry(handler, &data->handler, node) { | |
117 | pr_debug(KERN_INFO "pmi: notifying handler %p\n", handler); | |
118 | if (handler->type == data->msg.type) | |
813f9072 | 119 | handler->handle_pmi_message(data->msg); |
0e826643 CK |
120 | } |
121 | spin_unlock(&data->handler_spinlock); | |
122 | } | |
123 | ||
124 | static int pmi_of_probe(struct of_device *dev, | |
125 | const struct of_device_id *match) | |
126 | { | |
61c7a080 | 127 | struct device_node *np = dev->dev.of_node; |
0e826643 CK |
128 | int rc; |
129 | ||
813f9072 CK |
130 | if (data) { |
131 | printk(KERN_ERR "pmi: driver has already been initialized.\n"); | |
132 | rc = -EBUSY; | |
133 | goto out; | |
134 | } | |
135 | ||
0e826643 CK |
136 | data = kzalloc(sizeof(struct pmi_data), GFP_KERNEL); |
137 | if (!data) { | |
138 | printk(KERN_ERR "pmi: could not allocate memory.\n"); | |
139 | rc = -ENOMEM; | |
140 | goto out; | |
141 | } | |
142 | ||
6bf05fd7 | 143 | data->pmi_reg = of_iomap(np, 0); |
0e826643 CK |
144 | if (!data->pmi_reg) { |
145 | printk(KERN_ERR "pmi: invalid register address.\n"); | |
146 | rc = -EFAULT; | |
147 | goto error_cleanup_data; | |
148 | } | |
149 | ||
150 | INIT_LIST_HEAD(&data->handler); | |
151 | ||
152 | mutex_init(&data->msg_mutex); | |
153 | spin_lock_init(&data->pmi_spinlock); | |
154 | spin_lock_init(&data->handler_spinlock); | |
155 | ||
156 | INIT_WORK(&data->work, pmi_notify_handlers); | |
157 | ||
0e826643 CK |
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 | ||
813f9072 | 167 | rc = request_irq(data->irq, pmi_irq_handler, 0, "pmi", NULL); |
0e826643 CK |
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 | { | |
0e826643 CK |
190 | struct pmi_handler *handler, *tmp; |
191 | ||
813f9072 | 192 | free_irq(data->irq, NULL); |
0e826643 CK |
193 | iounmap(data->pmi_reg); |
194 | ||
195 | spin_lock(&data->handler_spinlock); | |
196 | ||
197 | list_for_each_entry_safe(handler, tmp, &data->handler, node) | |
198 | list_del(&handler->node); | |
199 | ||
200 | spin_unlock(&data->handler_spinlock); | |
201 | ||
813f9072 CK |
202 | kfree(data); |
203 | data = NULL; | |
0e826643 CK |
204 | |
205 | return 0; | |
206 | } | |
207 | ||
208 | static struct of_platform_driver pmi_of_platform_driver = { | |
0e826643 | 209 | .probe = pmi_of_probe, |
84dd4676 | 210 | .remove = pmi_of_remove, |
4018294b GL |
211 | .driver = { |
212 | .name = "pmi", | |
213 | .owner = THIS_MODULE, | |
214 | .of_match_table = pmi_match, | |
84dd4676 | 215 | }, |
0e826643 CK |
216 | }; |
217 | ||
218 | static int __init pmi_module_init(void) | |
219 | { | |
220 | return of_register_platform_driver(&pmi_of_platform_driver); | |
221 | } | |
222 | module_init(pmi_module_init); | |
223 | ||
224 | static void __exit pmi_module_exit(void) | |
225 | { | |
226 | of_unregister_platform_driver(&pmi_of_platform_driver); | |
227 | } | |
228 | module_exit(pmi_module_exit); | |
229 | ||
813f9072 | 230 | int pmi_send_message(pmi_message_t msg) |
0e826643 | 231 | { |
0e826643 CK |
232 | unsigned long flags; |
233 | DECLARE_COMPLETION_ONSTACK(completion); | |
234 | ||
813f9072 CK |
235 | if (!data) |
236 | return -ENODEV; | |
0e826643 CK |
237 | |
238 | mutex_lock(&data->msg_mutex); | |
239 | ||
240 | data->msg = msg; | |
241 | pr_debug("pmi_send_message: msg is %08x\n", *(u32*)&msg); | |
242 | ||
243 | data->completion = &completion; | |
244 | ||
245 | spin_lock_irqsave(&data->pmi_spinlock, flags); | |
246 | iowrite8(msg.data0, data->pmi_reg + PMI_WRITE_DATA0); | |
247 | iowrite8(msg.data1, data->pmi_reg + PMI_WRITE_DATA1); | |
248 | iowrite8(msg.data2, data->pmi_reg + PMI_WRITE_DATA2); | |
249 | iowrite8(msg.type, data->pmi_reg + PMI_WRITE_TYPE); | |
250 | spin_unlock_irqrestore(&data->pmi_spinlock, flags); | |
251 | ||
252 | pr_debug("pmi_send_message: wait for completion\n"); | |
253 | ||
254 | wait_for_completion_interruptible_timeout(data->completion, | |
255 | PMI_TIMEOUT); | |
256 | ||
257 | data->completion = NULL; | |
258 | ||
259 | mutex_unlock(&data->msg_mutex); | |
813f9072 CK |
260 | |
261 | return 0; | |
0e826643 CK |
262 | } |
263 | EXPORT_SYMBOL_GPL(pmi_send_message); | |
264 | ||
813f9072 | 265 | int pmi_register_handler(struct pmi_handler *handler) |
0e826643 | 266 | { |
79baf4a6 | 267 | if (!data) |
813f9072 | 268 | return -ENODEV; |
79baf4a6 | 269 | |
0e826643 CK |
270 | spin_lock(&data->handler_spinlock); |
271 | list_add_tail(&handler->node, &data->handler); | |
272 | spin_unlock(&data->handler_spinlock); | |
813f9072 CK |
273 | |
274 | return 0; | |
0e826643 CK |
275 | } |
276 | EXPORT_SYMBOL_GPL(pmi_register_handler); | |
277 | ||
813f9072 | 278 | void pmi_unregister_handler(struct pmi_handler *handler) |
0e826643 | 279 | { |
79baf4a6 CK |
280 | if (!data) |
281 | return; | |
0e826643 | 282 | |
79baf4a6 | 283 | pr_debug("pmi: unregistering handler %p\n", handler); |
0e826643 CK |
284 | |
285 | spin_lock(&data->handler_spinlock); | |
286 | list_del(&handler->node); | |
287 | spin_unlock(&data->handler_spinlock); | |
288 | } | |
289 | EXPORT_SYMBOL_GPL(pmi_unregister_handler); | |
290 | ||
291 | MODULE_LICENSE("GPL"); | |
292 | MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>"); | |
293 | MODULE_DESCRIPTION("IBM Platform Management Interrupt driver"); |