[mirror_ubuntu-artful-kernel.git] / drivers / mailbox / mailbox-test.c

/*
 * Copyright (C) 2015 ST Microelectronics
 *
 * Author: Lee Jones <lee.jones@linaro.org>
 *
 * 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 of the License, or
 * (at your option) any later version.
 */

#include <linux/debugfs.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/uaccess.h>

#define MBOX_MAX_SIG_LEN	8
#define MBOX_MAX_MSG_LEN	128
#define MBOX_BYTES_PER_LINE	16
#define MBOX_HEXDUMP_LINE_LEN	((MBOX_BYTES_PER_LINE * 4) + 2)
#define MBOX_HEXDUMP_MAX_LEN	(MBOX_HEXDUMP_LINE_LEN *		\
				 (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))

static struct dentry *root_debugfs_dir;

struct mbox_test_device {
	struct device		*dev;
	void __iomem		*tx_mmio;
	void __iomem		*rx_mmio;
	struct mbox_chan	*tx_channel;
	struct mbox_chan	*rx_channel;
	char			*rx_buffer;
	char			*signal;
	char			*message;
	spinlock_t		lock;
};

static ssize_t mbox_test_signal_write(struct file *filp,
				       const char __user *userbuf,
				       size_t count, loff_t *ppos)
{
	struct mbox_test_device *tdev = filp->private_data;

	if (!tdev->tx_channel) {
		dev_err(tdev->dev, "Channel cannot do Tx\n");
		return -EINVAL;
	}

	if (count > MBOX_MAX_SIG_LEN) {
		dev_err(tdev->dev,
			"Signal length %zd greater than max allowed %d\n",
			count, MBOX_MAX_SIG_LEN);
		return -EINVAL;
	}

	/* Only allocate memory if we need to */
	if (!tdev->signal) {
		tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
		if (!tdev->signal)
			return -ENOMEM;
	}

	if (copy_from_user(tdev->signal, userbuf, count)) {
		kfree(tdev->signal);
		tdev->signal = NULL;
		return -EFAULT;
	}

	return count;
}

static const struct file_operations mbox_test_signal_ops = {
	.write	= mbox_test_signal_write,
	.open	= simple_open,
	.llseek	= generic_file_llseek,
};

static ssize_t mbox_test_message_write(struct file *filp,
				       const char __user *userbuf,
				       size_t count, loff_t *ppos)
{
	struct mbox_test_device *tdev = filp->private_data;
	void *data;
	int ret;

	if (!tdev->tx_channel) {
		dev_err(tdev->dev, "Channel cannot do Tx\n");
		return -EINVAL;
	}

	if (count > MBOX_MAX_MSG_LEN) {
		dev_err(tdev->dev,
			"Message length %zd greater than max allowed %d\n",
			count, MBOX_MAX_MSG_LEN);
		return -EINVAL;
	}

	tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
	if (!tdev->message)
		return -ENOMEM;

	ret = copy_from_user(tdev->message, userbuf, count);
	if (ret) {
		ret = -EFAULT;
		goto out;
	}

	/*
	 * A separate signal is only of use if there is
	 * MMIO to subsequently pass the message through
	 */
	if (tdev->tx_mmio && tdev->signal) {
		print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
				     tdev->signal, MBOX_MAX_SIG_LEN);

		data = tdev->signal;
	} else
		data = tdev->message;

	print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
			     tdev->message, MBOX_MAX_MSG_LEN);

	ret = mbox_send_message(tdev->tx_channel, data);
	if (ret < 0)
		dev_err(tdev->dev, "Failed to send message via mailbox\n");

out:
	kfree(tdev->signal);
	kfree(tdev->message);

	return ret < 0 ? ret : count;
}

static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
				      size_t count, loff_t *ppos)
{
	struct mbox_test_device *tdev = filp->private_data;
	unsigned long flags;
	char *touser, *ptr;
	int l = 0;
	int ret;

	touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
	if (!touser)
		return -ENOMEM;

	if (!tdev->rx_channel) {
		ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
		ret = simple_read_from_buffer(userbuf, count, ppos,
					      touser, ret);
		goto out;
	}

	if (tdev->rx_buffer[0] == '\0') {
		ret = snprintf(touser, 9, "<EMPTY>\n");
		ret = simple_read_from_buffer(userbuf, count, ppos,
					      touser, ret);
		goto out;
	}

	spin_lock_irqsave(&tdev->lock, flags);

	ptr = tdev->rx_buffer;
	while (l < MBOX_HEXDUMP_MAX_LEN) {
		hex_dump_to_buffer(ptr,
				   MBOX_BYTES_PER_LINE,
				   MBOX_BYTES_PER_LINE, 1, touser + l,
				   MBOX_HEXDUMP_LINE_LEN, true);

		ptr += MBOX_BYTES_PER_LINE;
		l += MBOX_HEXDUMP_LINE_LEN;
		*(touser + (l - 1)) = '\n';
	}
	*(touser + l) = '\0';

	memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);

	spin_unlock_irqrestore(&tdev->lock, flags);

	ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
out:
	kfree(touser);
	return ret;
}

static const struct file_operations mbox_test_message_ops = {
	.write	= mbox_test_message_write,
	.read	= mbox_test_message_read,
	.open	= simple_open,
	.llseek	= generic_file_llseek,
};

static int mbox_test_add_debugfs(struct platform_device *pdev,
				 struct mbox_test_device *tdev)
{
	if (!debugfs_initialized())
		return 0;

	root_debugfs_dir = debugfs_create_dir("mailbox", NULL);
	if (!root_debugfs_dir) {
		dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
		return -EINVAL;
	}

	debugfs_create_file("message", 0600, root_debugfs_dir,
			    tdev, &mbox_test_message_ops);

	debugfs_create_file("signal", 0200, root_debugfs_dir,
			    tdev, &mbox_test_signal_ops);

	return 0;
}

static void mbox_test_receive_message(struct mbox_client *client, void *message)
{
	struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
	unsigned long flags;

	spin_lock_irqsave(&tdev->lock, flags);
	if (tdev->rx_mmio) {
		memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
		print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
				     tdev->rx_buffer, MBOX_MAX_MSG_LEN);
	} else if (message) {
		print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
				     message, MBOX_MAX_MSG_LEN);
		memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
	}
	spin_unlock_irqrestore(&tdev->lock, flags);
}

static void mbox_test_prepare_message(struct mbox_client *client, void *message)
{
	struct mbox_test_device *tdev = dev_get_drvdata(client->dev);

	if (tdev->tx_mmio) {
		if (tdev->signal)
			memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
		else
			memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
	}
}

static void mbox_test_message_sent(struct mbox_client *client,
				   void *message, int r)
{
	if (r)
		dev_warn(client->dev,
			 "Client: Message could not be sent: %d\n", r);
	else
		dev_info(client->dev,
			 "Client: Message sent\n");
}

static struct mbox_chan *
mbox_test_request_channel(struct platform_device *pdev, const char *name)
{
	struct mbox_client *client;
	struct mbox_chan *channel;

	client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
	if (!client)
		return ERR_PTR(-ENOMEM);

	client->dev		= &pdev->dev;
	client->rx_callback	= mbox_test_receive_message;
	client->tx_prepare	= mbox_test_prepare_message;
	client->tx_done		= mbox_test_message_sent;
	client->tx_block	= true;
	client->knows_txdone	= false;
	client->tx_tout		= 500;

	channel = mbox_request_channel_byname(client, name);
	if (IS_ERR(channel)) {
		dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
		return NULL;
	}

	return channel;
}

static int mbox_test_probe(struct platform_device *pdev)
{
	struct mbox_test_device *tdev;
	struct resource *res;
	int ret;

	tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
	if (!tdev)
		return -ENOMEM;

	/* It's okay for MMIO to be NULL */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	tdev->tx_mmio = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(tdev->tx_mmio))
		tdev->tx_mmio = NULL;

	/* If specified, second reg entry is Rx MMIO */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	tdev->rx_mmio = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(tdev->rx_mmio))
		tdev->rx_mmio = tdev->tx_mmio;

	tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
	tdev->rx_channel = mbox_test_request_channel(pdev, "rx");

	if (!tdev->tx_channel && !tdev->rx_channel)
		return -EPROBE_DEFER;

	/* If Rx is not specified but has Rx MMIO, then Rx = Tx */
	if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
		tdev->rx_channel = tdev->tx_channel;

	tdev->dev = &pdev->dev;
	platform_set_drvdata(pdev, tdev);

	spin_lock_init(&tdev->lock);

	if (tdev->rx_channel) {
		tdev->rx_buffer = devm_kzalloc(&pdev->dev,
					       MBOX_MAX_MSG_LEN, GFP_KERNEL);
		if (!tdev->rx_buffer)
			return -ENOMEM;
	}

	ret = mbox_test_add_debugfs(pdev, tdev);
	if (ret)
		return ret;

	dev_info(&pdev->dev, "Successfully registered\n");

	return 0;
}

static int mbox_test_remove(struct platform_device *pdev)
{
	struct mbox_test_device *tdev = platform_get_drvdata(pdev);

	debugfs_remove_recursive(root_debugfs_dir);

	if (tdev->tx_channel)
		mbox_free_channel(tdev->tx_channel);
	if (tdev->rx_channel)
		mbox_free_channel(tdev->rx_channel);

	return 0;
}

static const struct of_device_id mbox_test_match[] = {
	{ .compatible = "mailbox-test" },
	{},
};

static struct platform_driver mbox_test_driver = {
	.driver = {
		.name = "mailbox_test",
		.of_match_table = mbox_test_match,
	},
	.probe  = mbox_test_probe,
	.remove = mbox_test_remove,
};
module_platform_driver(mbox_test_driver);

MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
8ea4484d LJ	1	/*
	2	* Copyright (C) 2015 ST Microelectronics
	3	*
	4	* Author: Lee Jones <lee.jones@linaro.org>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*/
	11
	12	#include <linux/debugfs.h>
	13	#include <linux/err.h>
a133f8b6	14	#include <linux/io.h>
8ea4484d LJ	15	#include <linux/kernel.h>
	16	#include <linux/mailbox_client.h>
	17	#include <linux/module.h>
	18	#include <linux/of.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/slab.h>
	21	#include <linux/uaccess.h>
	22
	23	#define MBOX_MAX_SIG_LEN 8
	24	#define MBOX_MAX_MSG_LEN 128
	25	#define MBOX_BYTES_PER_LINE 16
6c03663f	26	#define MBOX_HEXDUMP_LINE_LEN ((MBOX_BYTES_PER_LINE * 4) + 2)
8ea4484d LJ	27	#define MBOX_HEXDUMP_MAX_LEN (MBOX_HEXDUMP_LINE_LEN * \
	28	(MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
	29
	30	static struct dentry *root_debugfs_dir;
	31
	32	struct mbox_test_device {
	33	struct device *dev;
2d74ffdc SH	34	void __iomem *tx_mmio;
2d74ffdc SH	35	void __iomem *rx_mmio;
8ea4484d LJ	36	struct mbox_chan *tx_channel;
	37	struct mbox_chan *rx_channel;
	38	char *rx_buffer;
	39	char *signal;
	40	char *message;
	41	spinlock_t lock;
	42	};
	43
	44	static ssize_t mbox_test_signal_write(struct file *filp,
	45	const char __user *userbuf,
	46	size_t count, loff_t *ppos)
	47	{
	48	struct mbox_test_device *tdev = filp->private_data;
8ea4484d LJ	49
	50	if (!tdev->tx_channel) {
	51	dev_err(tdev->dev, "Channel cannot do Tx\n");
	52	return -EINVAL;
	53	}
	54
	55	if (count > MBOX_MAX_SIG_LEN) {
	56	dev_err(tdev->dev,
6c03663f	57	"Signal length %zd greater than max allowed %d\n",
8ea4484d LJ	58	count, MBOX_MAX_SIG_LEN);
	59	return -EINVAL;
	60	}
	61
d1c2f87c LJ	62	/* Only allocate memory if we need to */
	63	if (!tdev->signal) {
	64	tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
	65	if (!tdev->signal)
	66	return -ENOMEM;
	67	}
8ea4484d	68
17f5f28f	69	if (copy_from_user(tdev->signal, userbuf, count)) {
8ea4484d	70	kfree(tdev->signal);
17f5f28f	71	tdev->signal = NULL;
8ea4484d LJ	72	return -EFAULT;
	73	}
	74
17f5f28f	75	return count;
8ea4484d LJ	76	}
	77
	78	static const struct file_operations mbox_test_signal_ops = {
	79	.write = mbox_test_signal_write,
	80	.open = simple_open,
	81	.llseek = generic_file_llseek,
	82	};
	83
	84	static ssize_t mbox_test_message_write(struct file *filp,
	85	const char __user *userbuf,
	86	size_t count, loff_t *ppos)
	87	{
	88	struct mbox_test_device *tdev = filp->private_data;
	89	void *data;
	90	int ret;
	91
	92	if (!tdev->tx_channel) {
	93	dev_err(tdev->dev, "Channel cannot do Tx\n");
	94	return -EINVAL;
	95	}
	96
	97	if (count > MBOX_MAX_MSG_LEN) {
	98	dev_err(tdev->dev,
6c03663f	99	"Message length %zd greater than max allowed %d\n",
8ea4484d LJ	100	count, MBOX_MAX_MSG_LEN);
	101	return -EINVAL;
	102	}
	103
	104	tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
	105	if (!tdev->message)
	106	return -ENOMEM;
	107
	108	ret = copy_from_user(tdev->message, userbuf, count);
	109	if (ret) {
	110	ret = -EFAULT;
	111	goto out;
	112	}
	113
	114	/*
	115	* A separate signal is only of use if there is
	116	* MMIO to subsequently pass the message through
	117	*/
2d74ffdc	118	if (tdev->tx_mmio && tdev->signal) {
27fa680f SH	119	print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
27fa680f SH	120	tdev->signal, MBOX_MAX_SIG_LEN);
8ea4484d LJ	121
	122	data = tdev->signal;
	123	} else
	124	data = tdev->message;
	125
27fa680f SH	126	print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
27fa680f SH	127	tdev->message, MBOX_MAX_MSG_LEN);
8ea4484d LJ	128
	129	ret = mbox_send_message(tdev->tx_channel, data);
	130	if (ret < 0)
	131	dev_err(tdev->dev, "Failed to send message via mailbox\n");
	132
	133	out:
	134	kfree(tdev->signal);
	135	kfree(tdev->message);
	136
	137	return ret < 0 ? ret : count;
	138	}
	139
	140	static ssize_t mbox_test_message_read(struct file filp, char __user userbuf,
	141	size_t count, loff_t *ppos)
	142	{
	143	struct mbox_test_device *tdev = filp->private_data;
	144	unsigned long flags;
	145	char touser, ptr;
	146	int l = 0;
	147	int ret;
	148
c3ac54a6	149	touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
8ea4484d LJ	150	if (!touser)
	151	return -ENOMEM;
	152
	153	if (!tdev->rx_channel) {
	154	ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
	155	ret = simple_read_from_buffer(userbuf, count, ppos,
	156	touser, ret);
	157	goto out;
	158	}
	159
	160	if (tdev->rx_buffer[0] == '\0') {
	161	ret = snprintf(touser, 9, "<EMPTY>\n");
	162	ret = simple_read_from_buffer(userbuf, count, ppos,
	163	touser, ret);
	164	goto out;
	165	}
	166
	167	spin_lock_irqsave(&tdev->lock, flags);
	168
	169	ptr = tdev->rx_buffer;
	170	while (l < MBOX_HEXDUMP_MAX_LEN) {
	171	hex_dump_to_buffer(ptr,
	172	MBOX_BYTES_PER_LINE,
	173	MBOX_BYTES_PER_LINE, 1, touser + l,
	174	MBOX_HEXDUMP_LINE_LEN, true);
	175
	176	ptr += MBOX_BYTES_PER_LINE;
	177	l += MBOX_HEXDUMP_LINE_LEN;
	178	*(touser + (l - 1)) = '\n';
	179	}
	180	*(touser + l) = '\0';
	181
	182	memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
	183
	184	spin_unlock_irqrestore(&tdev->lock, flags);
	185
	186	ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
	187	out:
	188	kfree(touser);
	189	return ret;
	190	}
	191
	192	static const struct file_operations mbox_test_message_ops = {
	193	.write = mbox_test_message_write,
	194	.read = mbox_test_message_read,
	195	.open = simple_open,
	196	.llseek = generic_file_llseek,
	197	};
	198
	199	static int mbox_test_add_debugfs(struct platform_device *pdev,
	200	struct mbox_test_device *tdev)
	201	{
	202	if (!debugfs_initialized())
	203	return 0;
	204
	205	root_debugfs_dir = debugfs_create_dir("mailbox", NULL);
	206	if (!root_debugfs_dir) {
	207	dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
	208	return -EINVAL;
	209	}
	210
	211	debugfs_create_file("message", 0600, root_debugfs_dir,
	212	tdev, &mbox_test_message_ops);
	213
214	debugfs_create_file("signal", 0200, root_debugfs_dir,
215	tdev, &mbox_test_signal_ops);
216
217	return 0;
218	}
219
220	static void mbox_test_receive_message(struct mbox_client client, void message)
221	{
222	struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
223	unsigned long flags;
224
225	spin_lock_irqsave(&tdev->lock, flags);
2d74ffdc SH	226	if (tdev->rx_mmio) {
2d74ffdc SH	227	memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
27fa680f SH	228	print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
27fa680f SH	229	tdev->rx_buffer, MBOX_MAX_MSG_LEN);
8ea4484d	230	} else if (message) {
27fa680f SH	231	print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
27fa680f SH	232	message, MBOX_MAX_MSG_LEN);
8ea4484d LJ	233	memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
	234	}
	235	spin_unlock_irqrestore(&tdev->lock, flags);
	236	}
	237
	238	static void mbox_test_prepare_message(struct mbox_client client, void message)
	239	{
	240	struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
	241
2d74ffdc	242	if (tdev->tx_mmio) {
8ea4484d	243	if (tdev->signal)
2d74ffdc	244	memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
8ea4484d	245	else
2d74ffdc	246	memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
8ea4484d LJ	247	}
	248	}
	249
	250	static void mbox_test_message_sent(struct mbox_client *client,
	251	void *message, int r)
	252	{
	253	if (r)
	254	dev_warn(client->dev,
	255	"Client: Message could not be sent: %d\n", r);
	256	else
	257	dev_info(client->dev,
	258	"Client: Message sent\n");
	259	}
	260
	261	static struct mbox_chan *
	262	mbox_test_request_channel(struct platform_device pdev, const char name)
	263	{
	264	struct mbox_client *client;
	265	struct mbox_chan *channel;
	266
	267	client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
	268	if (!client)
	269	return ERR_PTR(-ENOMEM);
	270
	271	client->dev = &pdev->dev;
	272	client->rx_callback = mbox_test_receive_message;
	273	client->tx_prepare = mbox_test_prepare_message;
	274	client->tx_done = mbox_test_message_sent;
	275	client->tx_block = true;
	276	client->knows_txdone = false;
	277	client->tx_tout = 500;
	278
	279	channel = mbox_request_channel_byname(client, name);
	280	if (IS_ERR(channel)) {
	281	dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
	282	return NULL;
	283	}
	284
	285	return channel;
	286	}
	287
	288	static int mbox_test_probe(struct platform_device *pdev)
	289	{
	290	struct mbox_test_device *tdev;
	291	struct resource *res;
	292	int ret;
	293
	294	tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
	295	if (!tdev)
	296	return -ENOMEM;
	297
	298	/* It's okay for MMIO to be NULL */
	299	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2d74ffdc SH	300	tdev->tx_mmio = devm_ioremap_resource(&pdev->dev, res);
	301	if (IS_ERR(tdev->tx_mmio))
	302	tdev->tx_mmio = NULL;
	303
	304	/* If specified, second reg entry is Rx MMIO */
	305	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	306	tdev->rx_mmio = devm_ioremap_resource(&pdev->dev, res);
	307	if (IS_ERR(tdev->rx_mmio))
	308	tdev->rx_mmio = tdev->tx_mmio;
8ea4484d LJ	309
	310	tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
	311	tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
	312
6c03663f	313	if (!tdev->tx_channel && !tdev->rx_channel)
8ea4484d LJ	314	return -EPROBE_DEFER;
8ea4484d LJ	315
2d74ffdc SH	316	/* If Rx is not specified but has Rx MMIO, then Rx = Tx */
	317	if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
	318	tdev->rx_channel = tdev->tx_channel;
	319
8ea4484d LJ	320	tdev->dev = &pdev->dev;
	321	platform_set_drvdata(pdev, tdev);
	322
	323	spin_lock_init(&tdev->lock);
	324
	325	if (tdev->rx_channel) {
	326	tdev->rx_buffer = devm_kzalloc(&pdev->dev,
	327	MBOX_MAX_MSG_LEN, GFP_KERNEL);
	328	if (!tdev->rx_buffer)
	329	return -ENOMEM;
	330	}
	331
	332	ret = mbox_test_add_debugfs(pdev, tdev);
	333	if (ret)
	334	return ret;
	335
	336	dev_info(&pdev->dev, "Successfully registered\n");
	337
	338	return 0;
	339	}
	340
	341	static int mbox_test_remove(struct platform_device *pdev)
	342	{
	343	struct mbox_test_device *tdev = platform_get_drvdata(pdev);
	344
	345	debugfs_remove_recursive(root_debugfs_dir);
	346
	347	if (tdev->tx_channel)
	348	mbox_free_channel(tdev->tx_channel);
	349	if (tdev->rx_channel)
	350	mbox_free_channel(tdev->rx_channel);
	351
	352	return 0;
	353	}
	354
	355	static const struct of_device_id mbox_test_match[] = {
c4280137	356	{ .compatible = "mailbox-test" },
8ea4484d LJ	357	{},
	358	};
	359
	360	static struct platform_driver mbox_test_driver = {
	361	.driver = {
adf06ba9	362	.name = "mailbox_test",
8ea4484d LJ	363	.of_match_table = mbox_test_match,
	364	},
	365	.probe = mbox_test_probe,
	366	.remove = mbox_test_remove,
	367	};
	368	module_platform_driver(mbox_test_driver);
	369
	370	MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
	371	MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
	372	MODULE_LICENSE("GPL v2");