[linux-block.git] / arch / powerpc / sysdev / pmi.c

// 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");
Commit	Line	Data
de6cc651	1	// SPDX-License-Identifier: GPL-2.0-or-later
0e826643 CK	2	/*
	3	* pmi driver
	4	*
	5	* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
	6	*
	7	* PMI (Platform Management Interrupt) is a way to communicate
	8	* with the BMC (Baseboard Management Controller) via interrupts.
	9	* Unlike IPMI it is bidirectional and has a low latency.
	10	*
	11	* Author: Christian Krafft <krafft@de.ibm.com>
0e826643 CK	12	*/
	13
	14	#include <linux/interrupt.h>
5a0e3ad6	15	#include <linux/slab.h>
0e826643 CK	16	#include <linux/completion.h>
0e826643 CK	17	#include <linux/spinlock.h>
7dfe293c	18	#include <linux/module.h>
0e826643	19	#include <linux/workqueue.h>
e6f6390a	20	#include <linux/of_address.h>
eb8f2763	21	#include <linux/of_device.h>
e6f6390a	22	#include <linux/of_irq.h>
eb8f2763	23	#include <linux/of_platform.h>
0e826643	24
0e826643 CK	25	#include <asm/io.h>
0e826643 CK	26	#include <asm/pmi.h>
0e826643 CK	27
	28	struct pmi_data {
	29	struct list_head handler;
	30	spinlock_t handler_spinlock;
	31	spinlock_t pmi_spinlock;
	32	struct mutex msg_mutex;
	33	pmi_message_t msg;
	34	struct completion *completion;
a454dc50	35	struct platform_device *dev;
0e826643 CK	36	int irq;
	37	u8 __iomem *pmi_reg;
	38	struct work_struct work;
	39	};
	40
813f9072	41	static struct pmi_data *data;
0e826643	42
fb247449	43	static irqreturn_t pmi_irq_handler(int irq, void *dev_id)
0e826643	44	{
0e826643 CK	45	u8 type;
	46	int rc;
	47
0e826643 CK	48	spin_lock(&data->pmi_spinlock);
	49
	50	type = ioread8(data->pmi_reg + PMI_READ_TYPE);
	51	pr_debug("pmi: got message of type %d\n", type);
	52
	53	if (type & PMI_ACK && !data->completion) {
	54	printk(KERN_WARNING "pmi: got unexpected ACK message.\n");
	55	rc = -EIO;
	56	goto unlock;
	57	}
	58
	59	if (data->completion && !(type & PMI_ACK)) {
	60	printk(KERN_WARNING "pmi: expected ACK, but got %d\n", type);
	61	rc = -EIO;
	62	goto unlock;
	63	}
	64
	65	data->msg.type = type;
	66	data->msg.data0 = ioread8(data->pmi_reg + PMI_READ_DATA0);
	67	data->msg.data1 = ioread8(data->pmi_reg + PMI_READ_DATA1);
	68	data->msg.data2 = ioread8(data->pmi_reg + PMI_READ_DATA2);
	69	rc = 0;
	70	unlock:
	71	spin_unlock(&data->pmi_spinlock);
	72
	73	if (rc == -EIO) {
	74	rc = IRQ_HANDLED;
	75	goto out;
	76	}
	77
	78	if (data->msg.type & PMI_ACK) {
	79	complete(data->completion);
	80	rc = IRQ_HANDLED;
	81	goto out;
	82	}
	83
	84	schedule_work(&data->work);
	85
	86	rc = IRQ_HANDLED;
	87	out:
	88	return rc;
	89	}
	90
	91
ce6d73c9	92	static const struct of_device_id pmi_match[] = {
0e826643	93	{ .type = "ibm,pmi", .name = "ibm,pmi" },
4a065f94	94	{ .type = "ibm,pmi" },
0e826643 CK	95	{},
	96	};
	97
	98	MODULE_DEVICE_TABLE(of, pmi_match);
	99
	100	static void pmi_notify_handlers(struct work_struct *work)
	101	{
0e826643 CK	102	struct pmi_handler *handler;
0e826643 CK	103
0e826643 CK	104	spin_lock(&data->handler_spinlock);
0e826643 CK	105	list_for_each_entry(handler, &data->handler, node) {
689fd14a	106	pr_debug("pmi: notifying handler %p\n", handler);
0e826643	107	if (handler->type == data->msg.type)
813f9072	108	handler->handle_pmi_message(data->msg);
0e826643 CK	109	}
	110	spin_unlock(&data->handler_spinlock);
	111	}
	112
00006124	113	static int pmi_of_probe(struct platform_device *dev)
0e826643	114	{
61c7a080	115	struct device_node *np = dev->dev.of_node;
0e826643 CK	116	int rc;
0e826643 CK	117
813f9072 CK	118	if (data) {
	119	printk(KERN_ERR "pmi: driver has already been initialized.\n");
	120	rc = -EBUSY;
	121	goto out;
	122	}
	123
0e826643 CK	124	data = kzalloc(sizeof(struct pmi_data), GFP_KERNEL);
	125	if (!data) {
	126	printk(KERN_ERR "pmi: could not allocate memory.\n");
	127	rc = -ENOMEM;
	128	goto out;
	129	}
	130
6bf05fd7	131	data->pmi_reg = of_iomap(np, 0);
0e826643 CK	132	if (!data->pmi_reg) {
	133	printk(KERN_ERR "pmi: invalid register address.\n");
	134	rc = -EFAULT;
	135	goto error_cleanup_data;
	136	}
	137
	138	INIT_LIST_HEAD(&data->handler);
	139
	140	mutex_init(&data->msg_mutex);
	141	spin_lock_init(&data->pmi_spinlock);
	142	spin_lock_init(&data->handler_spinlock);
	143
	144	INIT_WORK(&data->work, pmi_notify_handlers);
	145
0e826643 CK	146	data->dev = dev;
	147
	148	data->irq = irq_of_parse_and_map(np, 0);
ef24ba70	149	if (!data->irq) {
0e826643 CK	150	printk(KERN_ERR "pmi: invalid interrupt.\n");
	151	rc = -EFAULT;
	152	goto error_cleanup_iomap;
	153	}
	154
813f9072	155	rc = request_irq(data->irq, pmi_irq_handler, 0, "pmi", NULL);
0e826643 CK	156	if (rc) {
	157	printk(KERN_ERR "pmi: can't request IRQ %d: returned %d\n",
	158	data->irq, rc);
	159	goto error_cleanup_iomap;
	160	}
	161
	162	printk(KERN_INFO "pmi: found pmi device at addr %p.\n", data->pmi_reg);
	163
	164	goto out;
	165
	166	error_cleanup_iomap:
	167	iounmap(data->pmi_reg);
	168
	169	error_cleanup_data:
	170	kfree(data);
	171
	172	out:
	173	return rc;
	174	}
	175
a454dc50	176	static int pmi_of_remove(struct platform_device *dev)
0e826643	177	{
0e826643 CK	178	struct pmi_handler handler, tmp;
0e826643 CK	179
813f9072	180	free_irq(data->irq, NULL);
0e826643 CK	181	iounmap(data->pmi_reg);
	182
	183	spin_lock(&data->handler_spinlock);
	184
	185	list_for_each_entry_safe(handler, tmp, &data->handler, node)
	186	list_del(&handler->node);
	187
	188	spin_unlock(&data->handler_spinlock);
	189
813f9072 CK	190	kfree(data);
813f9072 CK	191	data = NULL;
0e826643 CK	192
	193	return 0;
	194	}
	195
00006124	196	static struct platform_driver pmi_of_platform_driver = {
0e826643	197	.probe = pmi_of_probe,
84dd4676	198	.remove = pmi_of_remove,
4018294b GL	199	.driver = {
4018294b GL	200	.name = "pmi",
4018294b	201	.of_match_table = pmi_match,
84dd4676	202	},
0e826643	203	};
40c935ae	204	module_platform_driver(pmi_of_platform_driver);
0e826643	205
813f9072	206	int pmi_send_message(pmi_message_t msg)
0e826643	207	{
0e826643 CK	208	unsigned long flags;
	209	DECLARE_COMPLETION_ONSTACK(completion);
	210
813f9072 CK	211	if (!data)
813f9072 CK	212	return -ENODEV;
0e826643 CK	213
	214	mutex_lock(&data->msg_mutex);
	215
	216	data->msg = msg;
	217	pr_debug("pmi_send_message: msg is %08x\n", (u32)&msg);
	218
	219	data->completion = &completion;
	220
	221	spin_lock_irqsave(&data->pmi_spinlock, flags);
	222	iowrite8(msg.data0, data->pmi_reg + PMI_WRITE_DATA0);
	223	iowrite8(msg.data1, data->pmi_reg + PMI_WRITE_DATA1);
	224	iowrite8(msg.data2, data->pmi_reg + PMI_WRITE_DATA2);
	225	iowrite8(msg.type, data->pmi_reg + PMI_WRITE_TYPE);
	226	spin_unlock_irqrestore(&data->pmi_spinlock, flags);
	227
	228	pr_debug("pmi_send_message: wait for completion\n");
	229
	230	wait_for_completion_interruptible_timeout(data->completion,
	231	PMI_TIMEOUT);
	232
	233	data->completion = NULL;
	234
	235	mutex_unlock(&data->msg_mutex);
813f9072 CK	236
813f9072 CK	237	return 0;
0e826643 CK	238	}
	239	EXPORT_SYMBOL_GPL(pmi_send_message);
	240
813f9072	241	int pmi_register_handler(struct pmi_handler *handler)
0e826643	242	{
79baf4a6	243	if (!data)
813f9072	244	return -ENODEV;
79baf4a6	245
0e826643 CK	246	spin_lock(&data->handler_spinlock);
	247	list_add_tail(&handler->node, &data->handler);
	248	spin_unlock(&data->handler_spinlock);
813f9072 CK	249
813f9072 CK	250	return 0;
0e826643 CK	251	}
	252	EXPORT_SYMBOL_GPL(pmi_register_handler);
	253
813f9072	254	void pmi_unregister_handler(struct pmi_handler *handler)
0e826643	255	{
79baf4a6 CK	256	if (!data)
79baf4a6 CK	257	return;
0e826643	258
79baf4a6	259	pr_debug("pmi: unregistering handler %p\n", handler);
0e826643 CK	260
	261	spin_lock(&data->handler_spinlock);
	262	list_del(&handler->node);
	263	spin_unlock(&data->handler_spinlock);
	264	}
	265	EXPORT_SYMBOL_GPL(pmi_unregister_handler);
	266
	267	MODULE_LICENSE("GPL");
	268	MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
	269	MODULE_DESCRIPTION("IBM Platform Management Interrupt driver");