Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * 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 = {

        .match_table    = pmi_match,

        .probe          = pmi_of_probe,

        .remove         = pmi_of_remove,

        .driver         = {

                .name   = "pmi",

        },

};

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");