1 files changed, 269 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/pmi.c b/arch/powerpc/sysdev/pmi.c
new file mode 100644
index 000000000..9dabb50c3
--- /dev/null
+++ b/arch/powerpc/sysdev/pmi.c
@@ -0,0 +1,269 @@
+// 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/workqueue.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.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 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",
+		.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");