blob: a5282011d39e6b2f4bb0a31008cc4729cc3ce60c [file] [log] [blame]
/*
* pmi driver
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
*
* PMI (Platform Management Interrupt) is a way to communicate
* with the BMC (Baseboard Management Controller) via interrupts.
* Unlike IPMI it is bidirectional and has a low latency.
*
* Author: Christian Krafft <krafft@de.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <asm/of_device.h>
#include <asm/of_platform.h>
#include <asm/io.h>
#include <asm/pmi.h>
struct pmi_data {
struct list_head handler;
spinlock_t handler_spinlock;
spinlock_t pmi_spinlock;
struct mutex msg_mutex;
pmi_message_t msg;
struct completion *completion;
struct of_device *dev;
int irq;
u8 __iomem *pmi_reg;
struct work_struct work;
};
static void __iomem *of_iomap(struct device_node *np)
{
struct resource res;
if (of_address_to_resource(np, 0, &res))
return NULL;
pr_debug("Resource start: 0x%lx\n", res.start);
pr_debug("Resource end: 0x%lx\n", res.end);
return ioremap(res.start, 1 + res.end - res.start);
}
static int pmi_irq_handler(int irq, void *dev_id)
{
struct pmi_data *data;
u8 type;
int rc;
data = dev_id;
spin_lock(&data->pmi_spinlock);
type = ioread8(data->pmi_reg + PMI_READ_TYPE);
pr_debug("pmi: got message of type %d\n", type);
if (type & PMI_ACK && !data->completion) {
printk(KERN_WARNING "pmi: got unexpected ACK message.\n");
rc = -EIO;
goto unlock;
}
if (data->completion && !(type & PMI_ACK)) {
printk(KERN_WARNING "pmi: expected ACK, but got %d\n", type);
rc = -EIO;
goto unlock;
}
data->msg.type = type;
data->msg.data0 = ioread8(data->pmi_reg + PMI_READ_DATA0);
data->msg.data1 = ioread8(data->pmi_reg + PMI_READ_DATA1);
data->msg.data2 = ioread8(data->pmi_reg + PMI_READ_DATA2);
rc = 0;
unlock:
spin_unlock(&data->pmi_spinlock);
if (rc == -EIO) {
rc = IRQ_HANDLED;
goto out;
}
if (data->msg.type & PMI_ACK) {
complete(data->completion);
rc = IRQ_HANDLED;
goto out;
}
schedule_work(&data->work);
rc = IRQ_HANDLED;
out:
return rc;
}
static struct of_device_id pmi_match[] = {
{ .type = "ibm,pmi", .name = "ibm,pmi" },
{},
};
MODULE_DEVICE_TABLE(of, pmi_match);
static void pmi_notify_handlers(struct work_struct *work)
{
struct pmi_data *data;
struct pmi_handler *handler;
data = container_of(work, struct pmi_data, work);
spin_lock(&data->handler_spinlock);
list_for_each_entry(handler, &data->handler, node) {
pr_debug(KERN_INFO "pmi: notifying handler %p\n", handler);
if (handler->type == data->msg.type)
handler->handle_pmi_message(data->dev, data->msg);
}
spin_unlock(&data->handler_spinlock);
}
static int pmi_of_probe(struct of_device *dev,
const struct of_device_id *match)
{
struct device_node *np = dev->node;
struct pmi_data *data;
int rc;
data = kzalloc(sizeof(struct pmi_data), GFP_KERNEL);
if (!data) {
printk(KERN_ERR "pmi: could not allocate memory.\n");
rc = -ENOMEM;
goto out;
}
data->pmi_reg = of_iomap(np);
if (!data->pmi_reg) {
printk(KERN_ERR "pmi: invalid register address.\n");
rc = -EFAULT;
goto error_cleanup_data;
}
INIT_LIST_HEAD(&data->handler);
mutex_init(&data->msg_mutex);
spin_lock_init(&data->pmi_spinlock);
spin_lock_init(&data->handler_spinlock);
INIT_WORK(&data->work, pmi_notify_handlers);
dev->dev.driver_data = data;
data->dev = dev;
data->irq = irq_of_parse_and_map(np, 0);
if (data->irq == NO_IRQ) {
printk(KERN_ERR "pmi: invalid interrupt.\n");
rc = -EFAULT;
goto error_cleanup_iomap;
}
rc = request_irq(data->irq, pmi_irq_handler, 0, "pmi", data);
if (rc) {
printk(KERN_ERR "pmi: can't request IRQ %d: returned %d\n",
data->irq, rc);
goto error_cleanup_iomap;
}
printk(KERN_INFO "pmi: found pmi device at addr %p.\n", data->pmi_reg);
goto out;
error_cleanup_iomap:
iounmap(data->pmi_reg);
error_cleanup_data:
kfree(data);
out:
return rc;
}
static int pmi_of_remove(struct of_device *dev)
{
struct pmi_data *data;
struct pmi_handler *handler, *tmp;
data = dev->dev.driver_data;
free_irq(data->irq, data);
iounmap(data->pmi_reg);
spin_lock(&data->handler_spinlock);
list_for_each_entry_safe(handler, tmp, &data->handler, node)
list_del(&handler->node);
spin_unlock(&data->handler_spinlock);
kfree(dev->dev.driver_data);
return 0;
}
static struct of_platform_driver pmi_of_platform_driver = {
.name = "pmi",
.match_table = pmi_match,
.probe = pmi_of_probe,
.remove = pmi_of_remove
};
static int __init pmi_module_init(void)
{
return of_register_platform_driver(&pmi_of_platform_driver);
}
module_init(pmi_module_init);
static void __exit pmi_module_exit(void)
{
of_unregister_platform_driver(&pmi_of_platform_driver);
}
module_exit(pmi_module_exit);
void pmi_send_message(struct of_device *device, pmi_message_t msg)
{
struct pmi_data *data;
unsigned long flags;
DECLARE_COMPLETION_ONSTACK(completion);
data = device->dev.driver_data;
mutex_lock(&data->msg_mutex);
data->msg = msg;
pr_debug("pmi_send_message: msg is %08x\n", *(u32*)&msg);
data->completion = &completion;
spin_lock_irqsave(&data->pmi_spinlock, flags);
iowrite8(msg.data0, data->pmi_reg + PMI_WRITE_DATA0);
iowrite8(msg.data1, data->pmi_reg + PMI_WRITE_DATA1);
iowrite8(msg.data2, data->pmi_reg + PMI_WRITE_DATA2);
iowrite8(msg.type, data->pmi_reg + PMI_WRITE_TYPE);
spin_unlock_irqrestore(&data->pmi_spinlock, flags);
pr_debug("pmi_send_message: wait for completion\n");
wait_for_completion_interruptible_timeout(data->completion,
PMI_TIMEOUT);
data->completion = NULL;
mutex_unlock(&data->msg_mutex);
}
EXPORT_SYMBOL_GPL(pmi_send_message);
void pmi_register_handler(struct of_device *device,
struct pmi_handler *handler)
{
struct pmi_data *data;
data = device->dev.driver_data;
spin_lock(&data->handler_spinlock);
list_add_tail(&handler->node, &data->handler);
spin_unlock(&data->handler_spinlock);
}
EXPORT_SYMBOL_GPL(pmi_register_handler);
void pmi_unregister_handler(struct of_device *device,
struct pmi_handler *handler)
{
struct pmi_data *data;
pr_debug("pmi: unregistering handler %p\n", handler);
data = device->dev.driver_data;
spin_lock(&data->handler_spinlock);
list_del(&handler->node);
spin_unlock(&data->handler_spinlock);
}
EXPORT_SYMBOL_GPL(pmi_unregister_handler);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
MODULE_DESCRIPTION("IBM Platform Management Interrupt driver");