mailbox: Add generic mechanism for testing Mailbox Controllers (8ea4484d) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/mailbox/Kconfig

+7 −0

Original line number	Diff line number	Diff line
		@@ -78,4 +78,11 @@ config STI_MBOX
		Mailbox implementation for STMicroelectonics family chips with
		hardware for interprocessor communication.

		config MAILBOX_TEST
		tristate "Mailbox Test Client"
		depends on OF
		help
		Test client to help with testing new Controller driver
		implementations.

		endif

drivers/mailbox/Makefile

+2 −0

Original line number	Diff line number	Diff line
		@@ -2,6 +2,8 @@

		obj-$(CONFIG_MAILBOX) += mailbox.o

		obj-$(CONFIG_MAILBOX_TEST) += mailbox-test.o

		obj-$(CONFIG_ARM_MHU) += arm_mhu.o

		obj-$(CONFIG_PL320_MBOX) += pl320-ipc.o

drivers/mailbox/mailbox-test.c

0 → 100644

+361 −0

Original line number	Diff line number	Diff line
		/*
		* 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/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 *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;
		int ret;

		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 %d greater than max allowed %d\n",
		count, MBOX_MAX_SIG_LEN);
		return -EINVAL;
		}

		tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
		if (!tdev->signal)
		return -ENOMEM;

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

		return ret < 0 ? ret : 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 %d 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->mmio && tdev->signal) {
		print_hex_dump(KERN_INFO, "Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
		MBOX_BYTES_PER_LINE, 1, tdev->signal, MBOX_MAX_SIG_LEN, true);

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

		print_hex_dump(KERN_INFO, "Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
		MBOX_BYTES_PER_LINE, 1, tdev->message, MBOX_MAX_MSG_LEN, true);

		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, 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->mmio) {
		print_hex_dump(KERN_INFO, "Client: Received [MMIO]: ",
		DUMP_PREFIX_ADDRESS, MBOX_BYTES_PER_LINE, 1,
		tdev->mmio, MBOX_MAX_MSG_LEN, true);
		memcpy(tdev->rx_buffer, tdev->mmio, MBOX_MAX_MSG_LEN);

		} else if (message) {
		print_hex_dump(KERN_INFO, "Client: Received [API]: ",
		DUMP_PREFIX_ADDRESS, MBOX_BYTES_PER_LINE, 1,
		message, MBOX_MAX_MSG_LEN, true);
		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->mmio) {
		if (tdev->signal)
		memcpy(tdev->mmio, tdev->message, MBOX_MAX_MSG_LEN);
		else
		memcpy(tdev->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->mmio = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(tdev->mmio))
		tdev->mmio = NULL;

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

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

		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_sti_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");