| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C) 2015 ST Microelectronics |
| * |
| * Author: Lee Jones <lee.jones@linaro.org> |
| */ |
| |
| #include <linux/debugfs.h> |
| #include <linux/err.h> |
| #include <linux/fs.h> |
| #include <linux/io.h> |
| #include <linux/kernel.h> |
| #include <linux/mailbox_client.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/of.h> |
| #include <linux/platform_device.h> |
| #include <linux/poll.h> |
| #include <linux/slab.h> |
| #include <linux/uaccess.h> |
| #include <linux/sched/signal.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 bool mbox_data_ready; |
| |
| 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; |
| struct mutex mutex; |
| wait_queue_head_t waitq; |
| struct fasync_struct *async_queue; |
| struct dentry *root_debugfs_dir; |
| }; |
| |
| 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 int mbox_test_message_fasync(int fd, struct file *filp, int on) |
| { |
| struct mbox_test_device *tdev = filp->private_data; |
| |
| return fasync_helper(fd, filp, on, &tdev->async_queue); |
| } |
| |
| 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; |
| char *message; |
| 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; |
| } |
| |
| message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL); |
| if (!message) |
| return -ENOMEM; |
| |
| mutex_lock(&tdev->mutex); |
| |
| tdev->message = message; |
| 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); |
| tdev->signal = NULL; |
| |
| mutex_unlock(&tdev->mutex); |
| |
| return ret < 0 ? ret : count; |
| } |
| |
| static bool mbox_test_message_data_ready(struct mbox_test_device *tdev) |
| { |
| bool data_ready; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&tdev->lock, flags); |
| data_ready = mbox_data_ready; |
| spin_unlock_irqrestore(&tdev->lock, flags); |
| |
| return data_ready; |
| } |
| |
| 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; |
| |
| DECLARE_WAITQUEUE(wait, current); |
| |
| 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 kfree_err; |
| } |
| |
| add_wait_queue(&tdev->waitq, &wait); |
| |
| do { |
| __set_current_state(TASK_INTERRUPTIBLE); |
| |
| if (mbox_test_message_data_ready(tdev)) |
| break; |
| |
| if (filp->f_flags & O_NONBLOCK) { |
| ret = -EAGAIN; |
| goto waitq_err; |
| } |
| |
| if (signal_pending(current)) { |
| ret = -ERESTARTSYS; |
| goto waitq_err; |
| } |
| schedule(); |
| |
| } while (1); |
| |
| 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); |
| mbox_data_ready = false; |
| |
| spin_unlock_irqrestore(&tdev->lock, flags); |
| |
| ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN); |
| waitq_err: |
| __set_current_state(TASK_RUNNING); |
| remove_wait_queue(&tdev->waitq, &wait); |
| kfree_err: |
| kfree(touser); |
| return ret; |
| } |
| |
| static __poll_t |
| mbox_test_message_poll(struct file *filp, struct poll_table_struct *wait) |
| { |
| struct mbox_test_device *tdev = filp->private_data; |
| |
| poll_wait(filp, &tdev->waitq, wait); |
| |
| if (mbox_test_message_data_ready(tdev)) |
| return EPOLLIN | EPOLLRDNORM; |
| return 0; |
| } |
| |
| static const struct file_operations mbox_test_message_ops = { |
| .write = mbox_test_message_write, |
| .read = mbox_test_message_read, |
| .fasync = mbox_test_message_fasync, |
| .poll = mbox_test_message_poll, |
| .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; |
| |
| tdev->root_debugfs_dir = debugfs_create_dir(dev_name(&pdev->dev), NULL); |
| if (!tdev->root_debugfs_dir) { |
| dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n"); |
| return -EINVAL; |
| } |
| |
| debugfs_create_file("message", 0600, tdev->root_debugfs_dir, |
| tdev, &mbox_test_message_ops); |
| |
| debugfs_create_file("signal", 0200, tdev->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); |
| } |
| mbox_data_ready = true; |
| spin_unlock_irqrestore(&tdev->lock, flags); |
| |
| wake_up_interruptible(&tdev->waitq); |
| |
| kill_fasync(&tdev->async_queue, SIGIO, POLL_IN); |
| } |
| |
| 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; |
| resource_size_t size; |
| 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 (PTR_ERR(tdev->tx_mmio) == -EBUSY) { |
| /* if reserved area in SRAM, try just ioremap */ |
| size = resource_size(res); |
| tdev->tx_mmio = devm_ioremap(&pdev->dev, res->start, size); |
| } else 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 (PTR_ERR(tdev->rx_mmio) == -EBUSY) { |
| size = resource_size(res); |
| tdev->rx_mmio = devm_ioremap(&pdev->dev, res->start, size); |
| } else 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); |
| mutex_init(&tdev->mutex); |
| |
| 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; |
| |
| init_waitqueue_head(&tdev->waitq); |
| 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(tdev->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" }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, mbox_test_match); |
| |
| 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"); |