/* * 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 * * 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 #include #include #include #include #include #include #include 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" }, { .type = "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; if (!data) return; 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; data = device->dev.driver_data; 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 "); MODULE_DESCRIPTION("IBM Platform Management Interrupt driver");