/* * 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/slab.h>#include <linux/completion.h>#include <linux/spinlock.h>#include <linux/module.h>#include <linux/workqueue.h>#include <linux/of_device.h>#include <linux/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 platform_device	*dev;	int			irq;	u8 __iomem		*pmi_reg;	struct work_struct	work;}; static struct pmi_data *data; static irqreturn_t 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("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 platform_device *dev){	struct device_node *np = dev->dev.of_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 platform_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 platform_driver pmi_of_platform_driver = {	.probe		= pmi_of_probe,	.remove		= pmi_of_remove,	.driver = {		.name = "pmi",		.owner = THIS_MODULE,		.of_match_table = pmi_match,	},};module_platform_driver(pmi_of_platform_driver); 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");