linux/arch/powerpc/sysdev/pmi.c
Christian Krafft 813f90728e [CELL] pmi: remove support for mutiple devices.
The pmi driver got simplified by removing support for multiple devices.
As there is no more than one pmi device per maschine, there is no need to
specify the device for listening and sending messages.

This way the caller (cbe_cpufreq) doesn't need to scan the device tree.
When registering the handler on a board without a pmi
interface, pmi.c will just return -ENODEV.

The patch that fixed the breakage of cell_defconfig has been
broken out of the earlier version of this patch. So this is
the version that applies cleanly on top of it.

Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
2007-07-20 21:41:34 +02:00

289 lines
6.5 KiB
C

/*
* 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>
#include <asm/prom.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 struct pmi_data *data;
static int pmi_irq_handler(int irq, void *dev_id)
{
u8 type;
int rc;
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" },
{ .type = "ibm,pmi" },
{},
};
MODULE_DEVICE_TABLE(of, pmi_match);
static void pmi_notify_handlers(struct work_struct *work)
{
struct pmi_handler *handler;
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->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;
int rc;
if (data) {
printk(KERN_ERR "pmi: driver has already been initialized.\n");
rc = -EBUSY;
goto out;
}
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, 0);
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);
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", NULL);
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_handler *handler, *tmp;
free_irq(data->irq, NULL);
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(data);
data = NULL;
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);
int pmi_send_message(pmi_message_t msg)
{
unsigned long flags;
DECLARE_COMPLETION_ONSTACK(completion);
if (!data)
return -ENODEV;
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);
return 0;
}
EXPORT_SYMBOL_GPL(pmi_send_message);
int pmi_register_handler(struct pmi_handler *handler)
{
if (!data)
return -ENODEV;
spin_lock(&data->handler_spinlock);
list_add_tail(&handler->node, &data->handler);
spin_unlock(&data->handler_spinlock);
return 0;
}
EXPORT_SYMBOL_GPL(pmi_register_handler);
void pmi_unregister_handler(struct pmi_handler *handler)
{
if (!data)
return;
pr_debug("pmi: unregistering handler %p\n", handler);
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");