+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * 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>
- */
-
-#include <linux/interrupt.h>
-#include <linux/slab.h>
-#include <linux/completion.h>
-#include <linux/spinlock.h>
-#include <linux/module.h>
-#include <linux/mod_devicetable.h>
-#include <linux/workqueue.h>
-#include <linux/of_address.h>
-#include <linux/of_irq.h>
-#include <linux/platform_device.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 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 const 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) {
- 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 void 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;
-}
-
-static struct platform_driver pmi_of_platform_driver = {
- .probe = pmi_of_probe,
- .remove = pmi_of_remove,
- .driver = {
- .name = "pmi",
- .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");
projects / nvme.git / commitdiff