#include #include #include #include #include #include #include #include #include #include #include #include #include // #define ENABLE_DEBUG ENABLE_DEBUG MODULE_LICENSE("GPL"); MODULE_AUTHOR("Markus Koch"); MODULE_DESCRIPTION("LW-35 I/O Controller Driver"); MODULE_VERSION("0.1"); static int debug_level = 0; module_param(debug_level, int, 0); MODULE_PARM_DESC(debug_level, "Debug level"); /* Only for chrdev... man they really suck! */ static struct serdev_device *static_serdev = NULL; static DECLARE_WAIT_QUEUE_HEAD(wq); static struct of_device_id lw35ioc_dt_ids[] = { { .compatible = "brother,lw35", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, lw35ioc_dt_ids); /* Chardev */ #define DEVICE_NAME "lw35" #define CLASS_NAME "lw35ioc" /* Only used for initialization, not for actualy keycode mapping */ static int keycode_map[] = { KEY_A, KEY_B, KEY_C, KEY_D, KEY_E, KEY_F, KEY_G, KEY_H, KEY_I, KEY_J, KEY_K, KEY_L, KEY_M, KEY_N, KEY_O, KEY_P, KEY_Q, KEY_R, KEY_S, KEY_T, KEY_U, KEY_V, KEY_W, KEY_X, KEY_Y, KEY_Z, KEY_0, KEY_1, KEY_2, KEY_3, KEY_4, KEY_5, KEY_6, KEY_7, KEY_8, KEY_9, KEY_F1, KEY_F2, KEY_F3, KEY_F4, KEY_F5, KEY_F6, KEY_F7, KEY_F8, KEY_F9, KEY_F10, KEY_F11, KEY_F12, KEY_UP, KEY_DOWN, KEY_RIGHT, KEY_LEFT, KEY_PAGEUP, KEY_PAGEDOWN, KEY_102ND, KEY_INSERT, KEY_HOME, KEY_END, KEY_PRINT, KEY_CAPSLOCK, KEY_LEFTCTRL, KEY_LEFTSHIFT, KEY_LEFTALT, KEY_TAB, KEY_MINUS, KEY_COMMA, KEY_SEMICOLON, KEY_RIGHTBRACE, KEY_LEFTBRACE, KEY_GRAVE, KEY_SPACE, KEY_EQUAL, KEY_DOT, KEY_SLASH, KEY_APOSTROPHE, KEY_BACKSLASH, KEY_DELETE, KEY_ESC, KEY_ENTER, KEY_BACKSPACE, KEY_SYSRQ }; enum lw35ioc_state {PASSIVE = 0, PROG_KBD, PROG_PRI, BYPASS, ACTIVE, STATE_COUNT}; enum lw35ioc_packet_state {SYNC, TYPE, KEYBOARD, PRINTER}; struct lw35ioc_packet { enum lw35ioc_packet_state state; }; struct lw35ioc_chardev { int major_number; struct class* class; struct device* device; int open_count; }; #define UART_BUF_SIZE 256 struct lw35ioc_priv { struct serdev_device *serdev; struct input_dev *input_dev; struct gpio_desc *gpio_rst; /* GPIO to reset both AVRs */ struct lw35ioc_chardev chardev; char uart_buf_rx[UART_BUF_SIZE]; char *uart_buf_rx_rd; char *uart_buf_rx_wr; enum lw35ioc_state state; struct lw35ioc_packet packet; }; static int lw35ioc_process_buf(struct serdev_device *serdev, const unsigned char *data, size_t count) { struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); unsigned char c; int ev; int i; #ifdef ENABLE_DEBUG dev_info(&serdev->dev, "IRQ.\n"); #endif for (i = 0; i < count; ++i) { c = data[i]; #ifdef ENABLE_DEBUG dev_info(&serdev->dev, " RX [%d]: %02x\n", priv->packet.state, c); #endif switch (priv->packet.state) { case SYNC: if (c == 0xFF) priv->packet.state = TYPE; break; case TYPE: if (c == 0x55) priv->packet.state = KEYBOARD; else if (c == 0xAA) priv->packet.state = PRINTER; else priv->packet.state = SYNC; break; case KEYBOARD: if (c > 127) { c -= 128; ev = 1; } else { ev = 0; } input_report_key(priv->input_dev, c, ev); input_sync(priv->input_dev); priv->packet.state = SYNC; break; case PRINTER: dev_info(&serdev->dev, "Printer not yet implemented.\n"); priv->packet.state = SYNC; break; } } return i; } static int lw35ioc_receive_buf(struct serdev_device *serdev, const unsigned char *data, size_t count) { struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); int i; if (priv->state == ACTIVE) return lw35ioc_process_buf(serdev, data, count); for (i = 0; i < count; ++i) { #ifdef ENABLE_DEBUG dev_info(&serdev->dev, " RX [PSV]: %02x\n", data[i]); #endif *(priv->uart_buf_rx_wr) = data[i]; if (priv->uart_buf_rx_wr == priv->uart_buf_rx + UART_BUF_SIZE - 1) priv->uart_buf_rx_wr = priv->uart_buf_rx; else priv->uart_buf_rx_wr++; if (priv->uart_buf_rx_rd == priv->uart_buf_rx_wr) { dev_err(&serdev->dev, "UART RX buffer overflow.\n"); } } wake_up_interruptible(&wq); return count; /* Pretend we read all data */ } static void lw35ioc_write_wakeup(struct serdev_device *serdev) { // schedule work here } static struct serdev_device_ops lw35ioc_serdev_ops = { .receive_buf = lw35ioc_receive_buf, .write_wakeup = lw35ioc_write_wakeup, }; static void lw35ioc_set_hw_reset(struct serdev_device *serdev, int reset_active) { struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); gpiod_set_value(priv->gpio_rst, !!reset_active); } static void lw35ioc_reset_ioc_hw(struct serdev_device *serdev) { dev_info(&serdev->dev, "Resetting IOC...\n"); lw35ioc_set_hw_reset(serdev, 1); usleep_range(90000, 100000); lw35ioc_set_hw_reset(serdev, 0); usleep_range(90000, 100000); } /* Chardev */ static int lw35ioc_chardev_open(struct inode *inodep, struct file *filep) { struct serdev_device *serdev = static_serdev; struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); filep->private_data = serdev; if (!priv->chardev.open_count) { dev_info(&serdev->dev, "Opened chardev.\n"); if (priv->state != ACTIVE && priv->state != PASSIVE) { lw35ioc_reset_ioc_hw(serdev); switch (priv->state) { case PROG_KBD: serdev_device_write(serdev, "X", 1, 0); dev_info(&serdev->dev, "Put ioc into programming mode: keyboard.\n"); break; case PROG_PRI: serdev_device_write(serdev, "Y", 1, 0); dev_info(&serdev->dev, "Put ioc into programming mode: printer.\n"); break; case BYPASS: serdev_device_write(serdev, "XX", 2, 0); dev_info(&serdev->dev, "Put ioc into bypass mode.\n"); break; default: /* For other modes, we just wait for the reset to be over */ usleep_range(1000000, 1010000); break; } } } else { dev_err(&serdev->dev, "Rejected. Device may only be opened once.\n"); //return -EBUSY; } priv->chardev.open_count++; return 0; } static ssize_t lw35ioc_chardev_read(struct file *filep, char *buffer, size_t len, loff_t *offset) { struct serdev_device *serdev = filep->private_data; struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); int error_count; int available; available = priv->uart_buf_rx_wr - priv->uart_buf_rx_rd; if (available < 0) available = 1; if (!available) { /* Wait for data to become available */ wait_event_interruptible(wq, priv->uart_buf_rx_rd != priv->uart_buf_rx_wr); available = priv->uart_buf_rx_wr - priv->uart_buf_rx_rd; if (available < 0) available = 1; if (!available) return -EAGAIN; } if (available < len) len = available; error_count = copy_to_user(buffer, priv->uart_buf_rx_rd, len); len -= error_count; priv->uart_buf_rx_rd += len; if (priv->uart_buf_rx_rd >= priv->uart_buf_rx + UART_BUF_SIZE) { priv->uart_buf_rx_rd -= UART_BUF_SIZE; } if (error_count == 0) { return len; } else { dev_err(&serdev->dev, "Failed to read %d characters to chardev.\n", error_count); return -EFAULT; } } char msg[256]; // TODO static ssize_t lw35ioc_chardev_write(struct file *filep, const char *buffer, size_t len, loff_t *offset) { struct serdev_device *serdev = filep->private_data; struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); if (len > 256) { len = 256; } copy_from_user(msg, buffer, len); serdev_device_write_buf(serdev, msg, len); return len; } static int lw35ioc_chardev_release(struct inode *inodep, struct file *filep){ struct serdev_device *serdev = filep->private_data; struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); priv->chardev.open_count--; dev_info(&serdev->dev, "Device successfully closed\n"); return 0; } #define IOCTL_SET_MODE 42 static long lw35ioc_chardev_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) { struct serdev_device *serdev = filep->private_data; struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); switch (cmd) { case IOCTL_SET_MODE: if (arg >= STATE_COUNT || arg < 0) { dev_err(&serdev->dev, "Invalid driver mode: %lu", arg); return -1; } priv->state = arg; dev_info(&serdev->dev, "Switched driver mode to: %lu. Will be applied with next open().\n", arg); break; default: dev_info(&serdev->dev, "Ignoring IOCTL %u(%lu)\n", cmd, arg); break; } return 0; } __poll_t poll(struct file *filep, struct poll_table_struct *ptab) { struct serdev_device *serdev = filep->private_data; struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); poll_wait(filep, &wq, ptab); if (priv->uart_buf_rx_wr != priv->uart_buf_rx_rd) return EPOLLIN | EPOLLRDNORM; return 0; } static struct file_operations fops = { .open = lw35ioc_chardev_open, .read = lw35ioc_chardev_read, .write = lw35ioc_chardev_write, .release = lw35ioc_chardev_release, .unlocked_ioctl = lw35ioc_chardev_ioctl, .poll = poll, }; static int lw35ioc_cdev_init(struct serdev_device *serdev) { struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); priv->chardev.open_count = 0; // Try to dynamically allocate a major number for the device priv->chardev.major_number = register_chrdev(0, DEVICE_NAME, &fops); if (priv->chardev.major_number < 0) { dev_err(&serdev->dev, "Failed to register a major number\n"); return priv->chardev.major_number; } dev_info(&serdev->dev, "Registered correctly with major number %d\n", priv->chardev.major_number); // Register the device class priv->chardev.class = class_create(THIS_MODULE, CLASS_NAME); if (IS_ERR(priv->chardev.class)) { unregister_chrdev(priv->chardev.major_number, DEVICE_NAME); dev_err(&serdev->dev, "Failed to register device class\n"); return PTR_ERR(priv->chardev.class); } dev_info(&serdev->dev, "Device class registered correctly\n"); // Register the device driver priv->chardev.device = device_create(priv->chardev.class, NULL, MKDEV(priv->chardev.major_number, 0), NULL, DEVICE_NAME); if (IS_ERR(priv->chardev.device)) { class_destroy(priv->chardev.class); unregister_chrdev(priv->chardev.major_number, DEVICE_NAME); dev_err(&serdev->dev, "Failed to create the device\n"); return PTR_ERR(priv->chardev.device); } dev_err(&serdev->dev, "Device class created correctly\n"); return 0; } static int lw35ioc_probe(struct serdev_device *serdev) { struct lw35ioc_priv *priv = NULL; int ret = 0; int i; u32 speed = 19200; struct input_dev *input_dev; printk(KERN_INFO "lw35ioc: probe\n"); if (static_serdev) { printk(KERN_ERR "lw35ioc: Can only be loaded once.\n"); goto fail_multicheck; } /* Allocate memory */ priv = devm_kzalloc(&serdev->dev, sizeof(struct lw35ioc_priv), GFP_KERNEL); if (!priv) { printk(KERN_ERR "lw35ioc: Not enough memory.\n"); return -ENOMEM; } priv->state = PASSIVE; priv->uart_buf_rx_rd = priv->uart_buf_rx; priv->uart_buf_rx_wr = priv->uart_buf_rx; priv->serdev = serdev; static_serdev = serdev; priv->packet.state = SYNC; serdev_device_set_drvdata(serdev, priv); serdev_device_set_client_ops(serdev, &lw35ioc_serdev_ops); /* Register input device */ input_dev = devm_input_allocate_device(&serdev->dev); if (!input_dev) { dev_err(&serdev->dev, "Unable to allocate input device.\n"); return -ENOMEM; } priv->input_dev = input_dev; input_dev->name = "lw35ioc"; input_dev->phys = "lw35ioc/input1"; input_set_capability(input_dev, EV_MSC, MSC_SCAN); __set_bit(EV_KEY, input_dev->evbit); __set_bit(EV_REP, input_dev->evbit); for (i = 0; i < ARRAY_SIZE(keycode_map); i++) __set_bit(keycode_map[i], input_dev->keybit); ret = input_register_device(input_dev); if (ret) { dev_err(&serdev->dev, "Unable to register input device.\n"); goto fail_input; } ret = serdev_device_open(serdev); if (ret) { dev_err(&serdev->dev, "Unable to open device.\n"); goto fail_serdev; } speed = serdev_device_set_baudrate(serdev, speed); dev_info(&serdev->dev, "Using baudrate: %u\n", speed); /* Register GPIO */ priv->gpio_rst = gpiod_get_index(&serdev->dev, "rst", 0, GPIOD_OUT_HIGH); /* Register character device */ ret = lw35ioc_cdev_init(serdev); if (ret) { dev_err(&serdev->dev, "Unable to initialize character device.\n"); goto fail_gpio; } if (IS_ERR(priv->gpio_rst)) { dev_err(&serdev->dev, "Unable to get reset GPIO.\n"); ret = -ENODEV; /* TODO */ goto fail_gpio; } lw35ioc_reset_ioc_hw(serdev); dev_info(&serdev->dev, "Loaded driver.\n"); return 0; fail_gpio: fail_serdev: input_unregister_device(input_dev); fail_input: devm_kfree(&serdev->dev, input_dev); fail_multicheck: return ret; } static void lw35ioc_remove(struct serdev_device *serdev) { struct lw35ioc_priv *priv = serdev_device_get_drvdata(serdev); device_destroy(priv->chardev.class, MKDEV(priv->chardev.major_number, 0)); class_unregister(priv->chardev.class); class_destroy(priv->chardev.class); unregister_chrdev(priv->chardev.major_number, DEVICE_NAME); lw35ioc_set_hw_reset(serdev, 1); gpiod_put(priv->gpio_rst); serdev_device_close(priv->serdev); input_unregister_device(priv->input_dev); dev_info(&serdev->dev, "remove\n"); return; } static struct serdev_device_driver lw35ioc_driver = { .probe = lw35ioc_probe, .remove = lw35ioc_remove, .driver = { .name = "lw35ioc", .owner = THIS_MODULE, .of_match_table = of_match_ptr(lw35ioc_dt_ids), }, }; module_serdev_device_driver(lw35ioc_driver);