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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> | |
7dfe293c | 31 | #include <linux/module.h> |
0e826643 | 32 | #include <linux/workqueue.h> |
eb8f2763 JL |
33 | #include <linux/of_device.h> |
34 | #include <linux/of_platform.h> | |
0e826643 | 35 | |
0e826643 CK |
36 | #include <asm/io.h> |
37 | #include <asm/pmi.h> | |
6bf05fd7 | 38 | #include <asm/prom.h> |
0e826643 CK |
39 | |
40 | struct pmi_data { | |
41 | struct list_head handler; | |
42 | spinlock_t handler_spinlock; | |
43 | spinlock_t pmi_spinlock; | |
44 | struct mutex msg_mutex; | |
45 | pmi_message_t msg; | |
46 | struct completion *completion; | |
a454dc50 | 47 | struct platform_device *dev; |
0e826643 CK |
48 | int irq; |
49 | u8 __iomem *pmi_reg; | |
50 | struct work_struct work; | |
51 | }; | |
52 | ||
813f9072 | 53 | static struct pmi_data *data; |
0e826643 | 54 | |
fb247449 | 55 | static irqreturn_t pmi_irq_handler(int irq, void *dev_id) |
0e826643 | 56 | { |
0e826643 CK |
57 | u8 type; |
58 | int rc; | |
59 | ||
0e826643 CK |
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 | { | |
0e826643 CK |
114 | struct pmi_handler *handler; |
115 | ||
0e826643 CK |
116 | spin_lock(&data->handler_spinlock); |
117 | list_for_each_entry(handler, &data->handler, node) { | |
689fd14a | 118 | pr_debug("pmi: notifying handler %p\n", handler); |
0e826643 | 119 | if (handler->type == data->msg.type) |
813f9072 | 120 | handler->handle_pmi_message(data->msg); |
0e826643 CK |
121 | } |
122 | spin_unlock(&data->handler_spinlock); | |
123 | } | |
124 | ||
00006124 | 125 | static int pmi_of_probe(struct platform_device *dev) |
0e826643 | 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 | ||
a454dc50 | 188 | static int pmi_of_remove(struct platform_device *dev) |
0e826643 | 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 | ||
00006124 | 208 | static struct 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 | { | |
00006124 | 220 | return platform_driver_register(&pmi_of_platform_driver); |
0e826643 CK |
221 | } |
222 | module_init(pmi_module_init); | |
223 | ||
224 | static void __exit pmi_module_exit(void) | |
225 | { | |
00006124 | 226 | platform_driver_unregister(&pmi_of_platform_driver); |
0e826643 CK |
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"); |