4 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
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.
10 * Author: Christian Krafft <krafft@de.ibm.com>
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)
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.
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.
27 #include <linux/interrupt.h>
28 #include <linux/completion.h>
29 #include <linux/spinlock.h>
30 #include <linux/workqueue.h>
32 #include <asm/of_device.h>
33 #include <asm/of_platform.h>
39 struct list_head handler;
40 spinlock_t handler_spinlock;
41 spinlock_t pmi_spinlock;
42 struct mutex msg_mutex;
44 struct completion *completion;
45 struct of_device *dev;
48 struct work_struct work;
53 static void __iomem *of_iomap(struct device_node *np)
57 if (of_address_to_resource(np, 0, &res))
60 pr_debug("Resource start: 0x%lx\n", res.start);
61 pr_debug("Resource end: 0x%lx\n", res.end);
63 return ioremap(res.start, 1 + res.end - res.start);
67 static int pmi_irq_handler(int irq, void *dev_id)
69 struct pmi_data *data;
75 spin_lock(&data->pmi_spinlock);
77 type = ioread8(data->pmi_reg + PMI_READ_TYPE);
78 pr_debug("pmi: got message of type %d\n", type);
80 if (type & PMI_ACK && !data->completion) {
81 printk(KERN_WARNING "pmi: got unexpected ACK message.\n");
86 if (data->completion && !(type & PMI_ACK)) {
87 printk(KERN_WARNING "pmi: expected ACK, but got %d\n", type);
92 data->msg.type = type;
93 data->msg.data0 = ioread8(data->pmi_reg + PMI_READ_DATA0);
94 data->msg.data1 = ioread8(data->pmi_reg + PMI_READ_DATA1);
95 data->msg.data2 = ioread8(data->pmi_reg + PMI_READ_DATA2);
98 spin_unlock(&data->pmi_spinlock);
105 if (data->msg.type & PMI_ACK) {
106 complete(data->completion);
111 schedule_work(&data->work);
119 static struct of_device_id pmi_match[] = {
120 { .type = "ibm,pmi", .name = "ibm,pmi" },
121 { .type = "ibm,pmi" },
125 MODULE_DEVICE_TABLE(of, pmi_match);
127 static void pmi_notify_handlers(struct work_struct *work)
129 struct pmi_data *data;
130 struct pmi_handler *handler;
132 data = container_of(work, struct pmi_data, work);
134 spin_lock(&data->handler_spinlock);
135 list_for_each_entry(handler, &data->handler, node) {
136 pr_debug(KERN_INFO "pmi: notifying handler %p\n", handler);
137 if (handler->type == data->msg.type)
138 handler->handle_pmi_message(data->dev, data->msg);
140 spin_unlock(&data->handler_spinlock);
143 static int pmi_of_probe(struct of_device *dev,
144 const struct of_device_id *match)
146 struct device_node *np = dev->node;
147 struct pmi_data *data;
150 data = kzalloc(sizeof(struct pmi_data), GFP_KERNEL);
152 printk(KERN_ERR "pmi: could not allocate memory.\n");
157 data->pmi_reg = of_iomap(np);
158 if (!data->pmi_reg) {
159 printk(KERN_ERR "pmi: invalid register address.\n");
161 goto error_cleanup_data;
164 INIT_LIST_HEAD(&data->handler);
166 mutex_init(&data->msg_mutex);
167 spin_lock_init(&data->pmi_spinlock);
168 spin_lock_init(&data->handler_spinlock);
170 INIT_WORK(&data->work, pmi_notify_handlers);
172 dev->dev.driver_data = data;
175 data->irq = irq_of_parse_and_map(np, 0);
176 if (data->irq == NO_IRQ) {
177 printk(KERN_ERR "pmi: invalid interrupt.\n");
179 goto error_cleanup_iomap;
182 rc = request_irq(data->irq, pmi_irq_handler, 0, "pmi", data);
184 printk(KERN_ERR "pmi: can't request IRQ %d: returned %d\n",
186 goto error_cleanup_iomap;
189 printk(KERN_INFO "pmi: found pmi device at addr %p.\n", data->pmi_reg);
194 iounmap(data->pmi_reg);
203 static int pmi_of_remove(struct of_device *dev)
205 struct pmi_data *data;
206 struct pmi_handler *handler, *tmp;
208 data = dev->dev.driver_data;
210 free_irq(data->irq, data);
211 iounmap(data->pmi_reg);
213 spin_lock(&data->handler_spinlock);
215 list_for_each_entry_safe(handler, tmp, &data->handler, node)
216 list_del(&handler->node);
218 spin_unlock(&data->handler_spinlock);
220 kfree(dev->dev.driver_data);
225 static struct of_platform_driver pmi_of_platform_driver = {
227 .match_table = pmi_match,
228 .probe = pmi_of_probe,
229 .remove = pmi_of_remove
232 static int __init pmi_module_init(void)
234 return of_register_platform_driver(&pmi_of_platform_driver);
236 module_init(pmi_module_init);
238 static void __exit pmi_module_exit(void)
240 of_unregister_platform_driver(&pmi_of_platform_driver);
242 module_exit(pmi_module_exit);
244 void pmi_send_message(struct of_device *device, pmi_message_t msg)
246 struct pmi_data *data;
248 DECLARE_COMPLETION_ONSTACK(completion);
250 data = device->dev.driver_data;
252 mutex_lock(&data->msg_mutex);
255 pr_debug("pmi_send_message: msg is %08x\n", *(u32*)&msg);
257 data->completion = &completion;
259 spin_lock_irqsave(&data->pmi_spinlock, flags);
260 iowrite8(msg.data0, data->pmi_reg + PMI_WRITE_DATA0);
261 iowrite8(msg.data1, data->pmi_reg + PMI_WRITE_DATA1);
262 iowrite8(msg.data2, data->pmi_reg + PMI_WRITE_DATA2);
263 iowrite8(msg.type, data->pmi_reg + PMI_WRITE_TYPE);
264 spin_unlock_irqrestore(&data->pmi_spinlock, flags);
266 pr_debug("pmi_send_message: wait for completion\n");
268 wait_for_completion_interruptible_timeout(data->completion,
271 data->completion = NULL;
273 mutex_unlock(&data->msg_mutex);
275 EXPORT_SYMBOL_GPL(pmi_send_message);
277 void pmi_register_handler(struct of_device *device,
278 struct pmi_handler *handler)
280 struct pmi_data *data;
281 data = device->dev.driver_data;
286 spin_lock(&data->handler_spinlock);
287 list_add_tail(&handler->node, &data->handler);
288 spin_unlock(&data->handler_spinlock);
290 EXPORT_SYMBOL_GPL(pmi_register_handler);
292 void pmi_unregister_handler(struct of_device *device,
293 struct pmi_handler *handler)
295 struct pmi_data *data;
296 data = device->dev.driver_data;
301 pr_debug("pmi: unregistering handler %p\n", handler);
303 spin_lock(&data->handler_spinlock);
304 list_del(&handler->node);
305 spin_unlock(&data->handler_spinlock);
307 EXPORT_SYMBOL_GPL(pmi_unregister_handler);
309 MODULE_LICENSE("GPL");
310 MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
311 MODULE_DESCRIPTION("IBM Platform Management Interrupt driver");