// SPDX-License-Identifier: GPL-2.0
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/*
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* UART driver for the Greybus "generic" UART module.
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*
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* Copyright 2014 Google Inc.
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* Copyright 2014 Linaro Ltd.
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*
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* Heavily based on drivers/usb/class/cdc-acm.c and
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* drivers/usb/serial/usb-serial.c.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/sched/signal.h>
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#include <linux/wait.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/mutex.h>
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#include <linux/tty.h>
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#include <linux/serial.h>
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#include <linux/tty_driver.h>
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#include <linux/tty_flip.h>
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#include <linux/idr.h>
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#include <linux/fs.h>
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#include <linux/kdev_t.h>
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#include <linux/kfifo.h>
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#include <linux/workqueue.h>
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#include <linux/completion.h>
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#include <linux/greybus.h>
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#include "gbphy.h"
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#define GB_NUM_MINORS 16 /* 16 is more than enough */
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#define GB_NAME "ttyGB"
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#define GB_UART_WRITE_FIFO_SIZE PAGE_SIZE
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#define GB_UART_WRITE_ROOM_MARGIN 1 /* leave some space in fifo */
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#define GB_UART_FIRMWARE_CREDITS 4096
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#define GB_UART_CREDIT_WAIT_TIMEOUT_MSEC 10000
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struct gb_tty {
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struct gbphy_device *gbphy_dev;
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struct tty_port port;
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void *buffer;
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size_t buffer_payload_max;
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struct gb_connection *connection;
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u16 cport_id;
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unsigned int minor;
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unsigned char clocal;
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bool disconnected;
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spinlock_t read_lock;
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spinlock_t write_lock;
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struct async_icount iocount;
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struct async_icount oldcount;
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wait_queue_head_t wioctl;
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struct mutex mutex;
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u8 ctrlin; /* input control lines */
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u8 ctrlout; /* output control lines */
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struct gb_uart_set_line_coding_request line_coding;
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struct work_struct tx_work;
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struct kfifo write_fifo;
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bool close_pending;
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unsigned int credits;
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struct completion credits_complete;
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};
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static struct tty_driver *gb_tty_driver;
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static DEFINE_IDR(tty_minors);
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static DEFINE_MUTEX(table_lock);
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static int gb_uart_receive_data_handler(struct gb_operation *op)
|
{
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struct gb_connection *connection = op->connection;
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struct gb_tty *gb_tty = gb_connection_get_data(connection);
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struct tty_port *port = &gb_tty->port;
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struct gb_message *request = op->request;
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struct gb_uart_recv_data_request *receive_data;
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u16 recv_data_size;
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int count;
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unsigned long tty_flags = TTY_NORMAL;
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if (request->payload_size < sizeof(*receive_data)) {
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dev_err(&gb_tty->gbphy_dev->dev,
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"short receive-data request received (%zu < %zu)\n",
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request->payload_size, sizeof(*receive_data));
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return -EINVAL;
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}
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receive_data = op->request->payload;
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recv_data_size = le16_to_cpu(receive_data->size);
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if (recv_data_size != request->payload_size - sizeof(*receive_data)) {
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dev_err(&gb_tty->gbphy_dev->dev,
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"malformed receive-data request received (%u != %zu)\n",
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recv_data_size,
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request->payload_size - sizeof(*receive_data));
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return -EINVAL;
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}
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if (!recv_data_size)
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return -EINVAL;
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if (receive_data->flags) {
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if (receive_data->flags & GB_UART_RECV_FLAG_BREAK)
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tty_flags = TTY_BREAK;
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else if (receive_data->flags & GB_UART_RECV_FLAG_PARITY)
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tty_flags = TTY_PARITY;
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else if (receive_data->flags & GB_UART_RECV_FLAG_FRAMING)
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tty_flags = TTY_FRAME;
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/* overrun is special, not associated with a char */
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if (receive_data->flags & GB_UART_RECV_FLAG_OVERRUN)
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tty_insert_flip_char(port, 0, TTY_OVERRUN);
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}
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count = tty_insert_flip_string_fixed_flag(port, receive_data->data,
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tty_flags, recv_data_size);
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if (count != recv_data_size) {
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dev_err(&gb_tty->gbphy_dev->dev,
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"UART: RX 0x%08x bytes only wrote 0x%08x\n",
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recv_data_size, count);
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}
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if (count)
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tty_flip_buffer_push(port);
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return 0;
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}
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static int gb_uart_serial_state_handler(struct gb_operation *op)
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{
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struct gb_connection *connection = op->connection;
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struct gb_tty *gb_tty = gb_connection_get_data(connection);
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struct gb_message *request = op->request;
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struct gb_uart_serial_state_request *serial_state;
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if (request->payload_size < sizeof(*serial_state)) {
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dev_err(&gb_tty->gbphy_dev->dev,
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"short serial-state event received (%zu < %zu)\n",
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request->payload_size, sizeof(*serial_state));
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return -EINVAL;
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}
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serial_state = request->payload;
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gb_tty->ctrlin = serial_state->control;
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return 0;
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}
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static int gb_uart_receive_credits_handler(struct gb_operation *op)
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{
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struct gb_connection *connection = op->connection;
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struct gb_tty *gb_tty = gb_connection_get_data(connection);
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struct gb_message *request = op->request;
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struct gb_uart_receive_credits_request *credit_request;
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unsigned long flags;
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unsigned int incoming_credits;
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int ret = 0;
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if (request->payload_size < sizeof(*credit_request)) {
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dev_err(&gb_tty->gbphy_dev->dev,
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"short receive_credits event received (%zu < %zu)\n",
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request->payload_size,
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sizeof(*credit_request));
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return -EINVAL;
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}
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credit_request = request->payload;
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incoming_credits = le16_to_cpu(credit_request->count);
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spin_lock_irqsave(&gb_tty->write_lock, flags);
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gb_tty->credits += incoming_credits;
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if (gb_tty->credits > GB_UART_FIRMWARE_CREDITS) {
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gb_tty->credits -= incoming_credits;
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ret = -EINVAL;
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}
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spin_unlock_irqrestore(&gb_tty->write_lock, flags);
|
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if (ret) {
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dev_err(&gb_tty->gbphy_dev->dev,
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"invalid number of incoming credits: %d\n",
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incoming_credits);
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return ret;
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}
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if (!gb_tty->close_pending)
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schedule_work(&gb_tty->tx_work);
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/*
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* the port the tty layer may be waiting for credits
|
*/
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tty_port_tty_wakeup(&gb_tty->port);
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if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS)
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complete(&gb_tty->credits_complete);
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return ret;
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}
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static int gb_uart_request_handler(struct gb_operation *op)
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{
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struct gb_connection *connection = op->connection;
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struct gb_tty *gb_tty = gb_connection_get_data(connection);
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int type = op->type;
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int ret;
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switch (type) {
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case GB_UART_TYPE_RECEIVE_DATA:
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ret = gb_uart_receive_data_handler(op);
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break;
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case GB_UART_TYPE_SERIAL_STATE:
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ret = gb_uart_serial_state_handler(op);
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break;
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case GB_UART_TYPE_RECEIVE_CREDITS:
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ret = gb_uart_receive_credits_handler(op);
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break;
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default:
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dev_err(&gb_tty->gbphy_dev->dev,
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"unsupported unsolicited request: 0x%02x\n", type);
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ret = -EINVAL;
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}
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return ret;
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}
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static void gb_uart_tx_write_work(struct work_struct *work)
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{
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struct gb_uart_send_data_request *request;
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struct gb_tty *gb_tty;
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unsigned long flags;
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unsigned int send_size;
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int ret;
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gb_tty = container_of(work, struct gb_tty, tx_work);
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request = gb_tty->buffer;
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|
while (1) {
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if (gb_tty->close_pending)
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break;
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spin_lock_irqsave(&gb_tty->write_lock, flags);
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send_size = gb_tty->buffer_payload_max;
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if (send_size > gb_tty->credits)
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send_size = gb_tty->credits;
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send_size = kfifo_out_peek(&gb_tty->write_fifo,
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&request->data[0],
|
send_size);
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if (!send_size) {
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spin_unlock_irqrestore(&gb_tty->write_lock, flags);
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break;
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}
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gb_tty->credits -= send_size;
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spin_unlock_irqrestore(&gb_tty->write_lock, flags);
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request->size = cpu_to_le16(send_size);
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ret = gb_operation_sync(gb_tty->connection,
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GB_UART_TYPE_SEND_DATA,
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request, sizeof(*request) + send_size,
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NULL, 0);
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if (ret) {
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dev_err(&gb_tty->gbphy_dev->dev,
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"send data error: %d\n", ret);
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spin_lock_irqsave(&gb_tty->write_lock, flags);
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gb_tty->credits += send_size;
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spin_unlock_irqrestore(&gb_tty->write_lock, flags);
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if (!gb_tty->close_pending)
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schedule_work(work);
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return;
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}
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spin_lock_irqsave(&gb_tty->write_lock, flags);
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ret = kfifo_out(&gb_tty->write_fifo, &request->data[0],
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send_size);
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spin_unlock_irqrestore(&gb_tty->write_lock, flags);
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tty_port_tty_wakeup(&gb_tty->port);
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}
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}
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static int send_line_coding(struct gb_tty *tty)
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{
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return gb_operation_sync(tty->connection, GB_UART_TYPE_SET_LINE_CODING,
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&tty->line_coding, sizeof(tty->line_coding),
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NULL, 0);
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}
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static int send_control(struct gb_tty *gb_tty, u8 control)
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{
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struct gb_uart_set_control_line_state_request request;
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request.control = control;
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return gb_operation_sync(gb_tty->connection,
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GB_UART_TYPE_SET_CONTROL_LINE_STATE,
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&request, sizeof(request), NULL, 0);
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}
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static int send_break(struct gb_tty *gb_tty, u8 state)
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{
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struct gb_uart_set_break_request request;
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if ((state != 0) && (state != 1)) {
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dev_err(&gb_tty->gbphy_dev->dev,
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"invalid break state of %d\n", state);
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return -EINVAL;
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}
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request.state = state;
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return gb_operation_sync(gb_tty->connection, GB_UART_TYPE_SEND_BREAK,
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&request, sizeof(request), NULL, 0);
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}
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static int gb_uart_wait_for_all_credits(struct gb_tty *gb_tty)
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{
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int ret;
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if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS)
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return 0;
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ret = wait_for_completion_timeout(&gb_tty->credits_complete,
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msecs_to_jiffies(GB_UART_CREDIT_WAIT_TIMEOUT_MSEC));
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if (!ret) {
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dev_err(&gb_tty->gbphy_dev->dev,
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"time out waiting for credits\n");
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return -ETIMEDOUT;
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}
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return 0;
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}
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static int gb_uart_flush(struct gb_tty *gb_tty, u8 flags)
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{
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struct gb_uart_serial_flush_request request;
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request.flags = flags;
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return gb_operation_sync(gb_tty->connection, GB_UART_TYPE_FLUSH_FIFOS,
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&request, sizeof(request), NULL, 0);
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}
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static struct gb_tty *get_gb_by_minor(unsigned int minor)
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{
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struct gb_tty *gb_tty;
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mutex_lock(&table_lock);
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gb_tty = idr_find(&tty_minors, minor);
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if (gb_tty) {
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mutex_lock(&gb_tty->mutex);
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if (gb_tty->disconnected) {
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mutex_unlock(&gb_tty->mutex);
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gb_tty = NULL;
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} else {
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tty_port_get(&gb_tty->port);
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mutex_unlock(&gb_tty->mutex);
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}
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}
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mutex_unlock(&table_lock);
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return gb_tty;
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}
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static int alloc_minor(struct gb_tty *gb_tty)
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{
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int minor;
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mutex_lock(&table_lock);
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minor = idr_alloc(&tty_minors, gb_tty, 0, GB_NUM_MINORS, GFP_KERNEL);
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mutex_unlock(&table_lock);
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if (minor >= 0)
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gb_tty->minor = minor;
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return minor;
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}
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static void release_minor(struct gb_tty *gb_tty)
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{
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int minor = gb_tty->minor;
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gb_tty->minor = 0; /* Maybe should use an invalid value instead */
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mutex_lock(&table_lock);
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idr_remove(&tty_minors, minor);
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mutex_unlock(&table_lock);
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}
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static int gb_tty_install(struct tty_driver *driver, struct tty_struct *tty)
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{
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struct gb_tty *gb_tty;
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int retval;
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gb_tty = get_gb_by_minor(tty->index);
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if (!gb_tty)
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return -ENODEV;
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retval = tty_standard_install(driver, tty);
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if (retval)
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goto error;
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tty->driver_data = gb_tty;
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return 0;
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error:
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tty_port_put(&gb_tty->port);
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return retval;
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}
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static int gb_tty_open(struct tty_struct *tty, struct file *file)
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{
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struct gb_tty *gb_tty = tty->driver_data;
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return tty_port_open(&gb_tty->port, tty, file);
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}
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static void gb_tty_close(struct tty_struct *tty, struct file *file)
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{
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struct gb_tty *gb_tty = tty->driver_data;
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tty_port_close(&gb_tty->port, tty, file);
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}
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static void gb_tty_cleanup(struct tty_struct *tty)
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{
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struct gb_tty *gb_tty = tty->driver_data;
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tty_port_put(&gb_tty->port);
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}
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static void gb_tty_hangup(struct tty_struct *tty)
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{
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struct gb_tty *gb_tty = tty->driver_data;
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tty_port_hangup(&gb_tty->port);
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}
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static int gb_tty_write(struct tty_struct *tty, const unsigned char *buf,
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int count)
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{
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struct gb_tty *gb_tty = tty->driver_data;
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count = kfifo_in_spinlocked(&gb_tty->write_fifo, buf, count,
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&gb_tty->write_lock);
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if (count && !gb_tty->close_pending)
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schedule_work(&gb_tty->tx_work);
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return count;
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}
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static int gb_tty_write_room(struct tty_struct *tty)
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{
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struct gb_tty *gb_tty = tty->driver_data;
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unsigned long flags;
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int room;
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spin_lock_irqsave(&gb_tty->write_lock, flags);
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room = kfifo_avail(&gb_tty->write_fifo);
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spin_unlock_irqrestore(&gb_tty->write_lock, flags);
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room -= GB_UART_WRITE_ROOM_MARGIN;
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if (room < 0)
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return 0;
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return room;
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}
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static int gb_tty_chars_in_buffer(struct tty_struct *tty)
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{
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struct gb_tty *gb_tty = tty->driver_data;
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unsigned long flags;
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int chars;
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spin_lock_irqsave(&gb_tty->write_lock, flags);
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chars = kfifo_len(&gb_tty->write_fifo);
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if (gb_tty->credits < GB_UART_FIRMWARE_CREDITS)
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chars += GB_UART_FIRMWARE_CREDITS - gb_tty->credits;
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spin_unlock_irqrestore(&gb_tty->write_lock, flags);
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return chars;
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}
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static int gb_tty_break_ctl(struct tty_struct *tty, int state)
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{
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struct gb_tty *gb_tty = tty->driver_data;
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return send_break(gb_tty, state ? 1 : 0);
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}
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static void gb_tty_set_termios(struct tty_struct *tty,
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struct ktermios *termios_old)
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{
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struct gb_uart_set_line_coding_request newline;
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struct gb_tty *gb_tty = tty->driver_data;
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struct ktermios *termios = &tty->termios;
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u8 newctrl = gb_tty->ctrlout;
|
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newline.rate = cpu_to_le32(tty_get_baud_rate(tty));
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newline.format = termios->c_cflag & CSTOPB ?
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GB_SERIAL_2_STOP_BITS : GB_SERIAL_1_STOP_BITS;
|
newline.parity = termios->c_cflag & PARENB ?
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(termios->c_cflag & PARODD ? 1 : 2) +
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(termios->c_cflag & CMSPAR ? 2 : 0) : 0;
|
|
switch (termios->c_cflag & CSIZE) {
|
case CS5:
|
newline.data_bits = 5;
|
break;
|
case CS6:
|
newline.data_bits = 6;
|
break;
|
case CS7:
|
newline.data_bits = 7;
|
break;
|
case CS8:
|
default:
|
newline.data_bits = 8;
|
break;
|
}
|
|
/* FIXME: needs to clear unsupported bits in the termios */
|
gb_tty->clocal = ((termios->c_cflag & CLOCAL) != 0);
|
|
if (C_BAUD(tty) == B0) {
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newline.rate = gb_tty->line_coding.rate;
|
newctrl &= ~(GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
|
} else if (termios_old && (termios_old->c_cflag & CBAUD) == B0) {
|
newctrl |= (GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
|
}
|
|
if (newctrl != gb_tty->ctrlout) {
|
gb_tty->ctrlout = newctrl;
|
send_control(gb_tty, newctrl);
|
}
|
|
if (C_CRTSCTS(tty) && C_BAUD(tty) != B0)
|
newline.flow_control = GB_SERIAL_AUTO_RTSCTS_EN;
|
else
|
newline.flow_control = 0;
|
|
if (memcmp(&gb_tty->line_coding, &newline, sizeof(newline))) {
|
memcpy(&gb_tty->line_coding, &newline, sizeof(newline));
|
send_line_coding(gb_tty);
|
}
|
}
|
|
static int gb_tty_tiocmget(struct tty_struct *tty)
|
{
|
struct gb_tty *gb_tty = tty->driver_data;
|
|
return (gb_tty->ctrlout & GB_UART_CTRL_DTR ? TIOCM_DTR : 0) |
|
(gb_tty->ctrlout & GB_UART_CTRL_RTS ? TIOCM_RTS : 0) |
|
(gb_tty->ctrlin & GB_UART_CTRL_DSR ? TIOCM_DSR : 0) |
|
(gb_tty->ctrlin & GB_UART_CTRL_RI ? TIOCM_RI : 0) |
|
(gb_tty->ctrlin & GB_UART_CTRL_DCD ? TIOCM_CD : 0) |
|
TIOCM_CTS;
|
}
|
|
static int gb_tty_tiocmset(struct tty_struct *tty, unsigned int set,
|
unsigned int clear)
|
{
|
struct gb_tty *gb_tty = tty->driver_data;
|
u8 newctrl = gb_tty->ctrlout;
|
|
set = (set & TIOCM_DTR ? GB_UART_CTRL_DTR : 0) |
|
(set & TIOCM_RTS ? GB_UART_CTRL_RTS : 0);
|
clear = (clear & TIOCM_DTR ? GB_UART_CTRL_DTR : 0) |
|
(clear & TIOCM_RTS ? GB_UART_CTRL_RTS : 0);
|
|
newctrl = (newctrl & ~clear) | set;
|
if (gb_tty->ctrlout == newctrl)
|
return 0;
|
|
gb_tty->ctrlout = newctrl;
|
return send_control(gb_tty, newctrl);
|
}
|
|
static void gb_tty_throttle(struct tty_struct *tty)
|
{
|
struct gb_tty *gb_tty = tty->driver_data;
|
unsigned char stop_char;
|
int retval;
|
|
if (I_IXOFF(tty)) {
|
stop_char = STOP_CHAR(tty);
|
retval = gb_tty_write(tty, &stop_char, 1);
|
if (retval <= 0)
|
return;
|
}
|
|
if (tty->termios.c_cflag & CRTSCTS) {
|
gb_tty->ctrlout &= ~GB_UART_CTRL_RTS;
|
retval = send_control(gb_tty, gb_tty->ctrlout);
|
}
|
}
|
|
static void gb_tty_unthrottle(struct tty_struct *tty)
|
{
|
struct gb_tty *gb_tty = tty->driver_data;
|
unsigned char start_char;
|
int retval;
|
|
if (I_IXOFF(tty)) {
|
start_char = START_CHAR(tty);
|
retval = gb_tty_write(tty, &start_char, 1);
|
if (retval <= 0)
|
return;
|
}
|
|
if (tty->termios.c_cflag & CRTSCTS) {
|
gb_tty->ctrlout |= GB_UART_CTRL_RTS;
|
retval = send_control(gb_tty, gb_tty->ctrlout);
|
}
|
}
|
|
static int get_serial_info(struct tty_struct *tty,
|
struct serial_struct *ss)
|
{
|
struct gb_tty *gb_tty = tty->driver_data;
|
|
ss->type = PORT_16550A;
|
ss->line = gb_tty->minor;
|
ss->xmit_fifo_size = 16;
|
ss->baud_base = 9600;
|
ss->close_delay = jiffies_to_msecs(gb_tty->port.close_delay) / 10;
|
ss->closing_wait =
|
gb_tty->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
|
ASYNC_CLOSING_WAIT_NONE :
|
jiffies_to_msecs(gb_tty->port.closing_wait) / 10;
|
|
return 0;
|
}
|
|
static int set_serial_info(struct tty_struct *tty,
|
struct serial_struct *ss)
|
{
|
struct gb_tty *gb_tty = tty->driver_data;
|
unsigned int closing_wait;
|
unsigned int close_delay;
|
int retval = 0;
|
|
close_delay = msecs_to_jiffies(ss->close_delay * 10);
|
closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
|
ASYNC_CLOSING_WAIT_NONE :
|
msecs_to_jiffies(ss->closing_wait * 10);
|
|
mutex_lock(&gb_tty->port.mutex);
|
if (!capable(CAP_SYS_ADMIN)) {
|
if ((close_delay != gb_tty->port.close_delay) ||
|
(closing_wait != gb_tty->port.closing_wait))
|
retval = -EPERM;
|
} else {
|
gb_tty->port.close_delay = close_delay;
|
gb_tty->port.closing_wait = closing_wait;
|
}
|
mutex_unlock(&gb_tty->port.mutex);
|
return retval;
|
}
|
|
static int wait_serial_change(struct gb_tty *gb_tty, unsigned long arg)
|
{
|
int retval = 0;
|
DECLARE_WAITQUEUE(wait, current);
|
struct async_icount old;
|
struct async_icount new;
|
|
if (!(arg & (TIOCM_DSR | TIOCM_RI | TIOCM_CD)))
|
return -EINVAL;
|
|
do {
|
spin_lock_irq(&gb_tty->read_lock);
|
old = gb_tty->oldcount;
|
new = gb_tty->iocount;
|
gb_tty->oldcount = new;
|
spin_unlock_irq(&gb_tty->read_lock);
|
|
if ((arg & TIOCM_DSR) && (old.dsr != new.dsr))
|
break;
|
if ((arg & TIOCM_CD) && (old.dcd != new.dcd))
|
break;
|
if ((arg & TIOCM_RI) && (old.rng != new.rng))
|
break;
|
|
add_wait_queue(&gb_tty->wioctl, &wait);
|
set_current_state(TASK_INTERRUPTIBLE);
|
schedule();
|
remove_wait_queue(&gb_tty->wioctl, &wait);
|
if (gb_tty->disconnected) {
|
if (arg & TIOCM_CD)
|
break;
|
retval = -ENODEV;
|
} else if (signal_pending(current)) {
|
retval = -ERESTARTSYS;
|
}
|
} while (!retval);
|
|
return retval;
|
}
|
|
static int gb_tty_get_icount(struct tty_struct *tty,
|
struct serial_icounter_struct *icount)
|
{
|
struct gb_tty *gb_tty = tty->driver_data;
|
|
icount->dsr = gb_tty->iocount.dsr;
|
icount->rng = gb_tty->iocount.rng;
|
icount->dcd = gb_tty->iocount.dcd;
|
icount->frame = gb_tty->iocount.frame;
|
icount->overrun = gb_tty->iocount.overrun;
|
icount->parity = gb_tty->iocount.parity;
|
icount->brk = gb_tty->iocount.brk;
|
|
return 0;
|
}
|
|
static int gb_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
|
unsigned long arg)
|
{
|
struct gb_tty *gb_tty = tty->driver_data;
|
|
switch (cmd) {
|
case TIOCMIWAIT:
|
return wait_serial_change(gb_tty, arg);
|
}
|
|
return -ENOIOCTLCMD;
|
}
|
|
static void gb_tty_dtr_rts(struct tty_port *port, int on)
|
{
|
struct gb_tty *gb_tty;
|
u8 newctrl;
|
|
gb_tty = container_of(port, struct gb_tty, port);
|
newctrl = gb_tty->ctrlout;
|
|
if (on)
|
newctrl |= (GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
|
else
|
newctrl &= ~(GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
|
|
gb_tty->ctrlout = newctrl;
|
send_control(gb_tty, newctrl);
|
}
|
|
static int gb_tty_port_activate(struct tty_port *port,
|
struct tty_struct *tty)
|
{
|
struct gb_tty *gb_tty;
|
|
gb_tty = container_of(port, struct gb_tty, port);
|
|
return gbphy_runtime_get_sync(gb_tty->gbphy_dev);
|
}
|
|
static void gb_tty_port_shutdown(struct tty_port *port)
|
{
|
struct gb_tty *gb_tty;
|
unsigned long flags;
|
int ret;
|
|
gb_tty = container_of(port, struct gb_tty, port);
|
|
gb_tty->close_pending = true;
|
|
cancel_work_sync(&gb_tty->tx_work);
|
|
spin_lock_irqsave(&gb_tty->write_lock, flags);
|
kfifo_reset_out(&gb_tty->write_fifo);
|
spin_unlock_irqrestore(&gb_tty->write_lock, flags);
|
|
if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS)
|
goto out;
|
|
ret = gb_uart_flush(gb_tty, GB_SERIAL_FLAG_FLUSH_TRANSMITTER);
|
if (ret) {
|
dev_err(&gb_tty->gbphy_dev->dev,
|
"error flushing transmitter: %d\n", ret);
|
}
|
|
gb_uart_wait_for_all_credits(gb_tty);
|
|
out:
|
gb_tty->close_pending = false;
|
|
gbphy_runtime_put_autosuspend(gb_tty->gbphy_dev);
|
}
|
|
static void gb_tty_port_destruct(struct tty_port *port)
|
{
|
struct gb_tty *gb_tty = container_of(port, struct gb_tty, port);
|
|
if (gb_tty->minor != GB_NUM_MINORS)
|
release_minor(gb_tty);
|
kfifo_free(&gb_tty->write_fifo);
|
kfree(gb_tty->buffer);
|
kfree(gb_tty);
|
}
|
|
static const struct tty_operations gb_ops = {
|
.install = gb_tty_install,
|
.open = gb_tty_open,
|
.close = gb_tty_close,
|
.cleanup = gb_tty_cleanup,
|
.hangup = gb_tty_hangup,
|
.write = gb_tty_write,
|
.write_room = gb_tty_write_room,
|
.ioctl = gb_tty_ioctl,
|
.throttle = gb_tty_throttle,
|
.unthrottle = gb_tty_unthrottle,
|
.chars_in_buffer = gb_tty_chars_in_buffer,
|
.break_ctl = gb_tty_break_ctl,
|
.set_termios = gb_tty_set_termios,
|
.tiocmget = gb_tty_tiocmget,
|
.tiocmset = gb_tty_tiocmset,
|
.get_icount = gb_tty_get_icount,
|
.set_serial = set_serial_info,
|
.get_serial = get_serial_info,
|
};
|
|
static const struct tty_port_operations gb_port_ops = {
|
.dtr_rts = gb_tty_dtr_rts,
|
.activate = gb_tty_port_activate,
|
.shutdown = gb_tty_port_shutdown,
|
.destruct = gb_tty_port_destruct,
|
};
|
|
static int gb_uart_probe(struct gbphy_device *gbphy_dev,
|
const struct gbphy_device_id *id)
|
{
|
struct gb_connection *connection;
|
size_t max_payload;
|
struct gb_tty *gb_tty;
|
struct device *tty_dev;
|
int retval;
|
int minor;
|
|
connection = gb_connection_create(gbphy_dev->bundle,
|
le16_to_cpu(gbphy_dev->cport_desc->id),
|
gb_uart_request_handler);
|
if (IS_ERR(connection))
|
return PTR_ERR(connection);
|
|
max_payload = gb_operation_get_payload_size_max(connection);
|
if (max_payload < sizeof(struct gb_uart_send_data_request)) {
|
retval = -EINVAL;
|
goto exit_connection_destroy;
|
}
|
|
gb_tty = kzalloc(sizeof(*gb_tty), GFP_KERNEL);
|
if (!gb_tty) {
|
retval = -ENOMEM;
|
goto exit_connection_destroy;
|
}
|
|
tty_port_init(&gb_tty->port);
|
gb_tty->port.ops = &gb_port_ops;
|
gb_tty->minor = GB_NUM_MINORS;
|
|
gb_tty->buffer_payload_max = max_payload -
|
sizeof(struct gb_uart_send_data_request);
|
|
gb_tty->buffer = kzalloc(gb_tty->buffer_payload_max, GFP_KERNEL);
|
if (!gb_tty->buffer) {
|
retval = -ENOMEM;
|
goto exit_put_port;
|
}
|
|
INIT_WORK(&gb_tty->tx_work, gb_uart_tx_write_work);
|
|
retval = kfifo_alloc(&gb_tty->write_fifo, GB_UART_WRITE_FIFO_SIZE,
|
GFP_KERNEL);
|
if (retval)
|
goto exit_put_port;
|
|
gb_tty->credits = GB_UART_FIRMWARE_CREDITS;
|
init_completion(&gb_tty->credits_complete);
|
|
minor = alloc_minor(gb_tty);
|
if (minor < 0) {
|
if (minor == -ENOSPC) {
|
dev_err(&gbphy_dev->dev,
|
"no more free minor numbers\n");
|
retval = -ENODEV;
|
} else {
|
retval = minor;
|
}
|
goto exit_put_port;
|
}
|
|
gb_tty->minor = minor;
|
spin_lock_init(&gb_tty->write_lock);
|
spin_lock_init(&gb_tty->read_lock);
|
init_waitqueue_head(&gb_tty->wioctl);
|
mutex_init(&gb_tty->mutex);
|
|
gb_tty->connection = connection;
|
gb_tty->gbphy_dev = gbphy_dev;
|
gb_connection_set_data(connection, gb_tty);
|
gb_gbphy_set_data(gbphy_dev, gb_tty);
|
|
retval = gb_connection_enable_tx(connection);
|
if (retval)
|
goto exit_put_port;
|
|
send_control(gb_tty, gb_tty->ctrlout);
|
|
/* initialize the uart to be 9600n81 */
|
gb_tty->line_coding.rate = cpu_to_le32(9600);
|
gb_tty->line_coding.format = GB_SERIAL_1_STOP_BITS;
|
gb_tty->line_coding.parity = GB_SERIAL_NO_PARITY;
|
gb_tty->line_coding.data_bits = 8;
|
send_line_coding(gb_tty);
|
|
retval = gb_connection_enable(connection);
|
if (retval)
|
goto exit_connection_disable;
|
|
tty_dev = tty_port_register_device(&gb_tty->port, gb_tty_driver, minor,
|
&gbphy_dev->dev);
|
if (IS_ERR(tty_dev)) {
|
retval = PTR_ERR(tty_dev);
|
goto exit_connection_disable;
|
}
|
|
gbphy_runtime_put_autosuspend(gbphy_dev);
|
return 0;
|
|
exit_connection_disable:
|
gb_connection_disable(connection);
|
exit_put_port:
|
tty_port_put(&gb_tty->port);
|
exit_connection_destroy:
|
gb_connection_destroy(connection);
|
|
return retval;
|
}
|
|
static void gb_uart_remove(struct gbphy_device *gbphy_dev)
|
{
|
struct gb_tty *gb_tty = gb_gbphy_get_data(gbphy_dev);
|
struct gb_connection *connection = gb_tty->connection;
|
struct tty_struct *tty;
|
int ret;
|
|
ret = gbphy_runtime_get_sync(gbphy_dev);
|
if (ret)
|
gbphy_runtime_get_noresume(gbphy_dev);
|
|
mutex_lock(&gb_tty->mutex);
|
gb_tty->disconnected = true;
|
|
wake_up_all(&gb_tty->wioctl);
|
mutex_unlock(&gb_tty->mutex);
|
|
tty = tty_port_tty_get(&gb_tty->port);
|
if (tty) {
|
tty_vhangup(tty);
|
tty_kref_put(tty);
|
}
|
|
gb_connection_disable_rx(connection);
|
tty_unregister_device(gb_tty_driver, gb_tty->minor);
|
|
gb_connection_disable(connection);
|
gb_connection_destroy(connection);
|
|
tty_port_put(&gb_tty->port);
|
}
|
|
static int gb_tty_init(void)
|
{
|
int retval = 0;
|
|
gb_tty_driver = tty_alloc_driver(GB_NUM_MINORS, 0);
|
if (IS_ERR(gb_tty_driver)) {
|
pr_err("Can not allocate tty driver\n");
|
retval = -ENOMEM;
|
goto fail_unregister_dev;
|
}
|
|
gb_tty_driver->driver_name = "gb";
|
gb_tty_driver->name = GB_NAME;
|
gb_tty_driver->major = 0;
|
gb_tty_driver->minor_start = 0;
|
gb_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
|
gb_tty_driver->subtype = SERIAL_TYPE_NORMAL;
|
gb_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
|
gb_tty_driver->init_termios = tty_std_termios;
|
gb_tty_driver->init_termios.c_cflag = B9600 | CS8 |
|
CREAD | HUPCL | CLOCAL;
|
tty_set_operations(gb_tty_driver, &gb_ops);
|
|
retval = tty_register_driver(gb_tty_driver);
|
if (retval) {
|
pr_err("Can not register tty driver: %d\n", retval);
|
goto fail_put_gb_tty;
|
}
|
|
return 0;
|
|
fail_put_gb_tty:
|
put_tty_driver(gb_tty_driver);
|
fail_unregister_dev:
|
return retval;
|
}
|
|
static void gb_tty_exit(void)
|
{
|
tty_unregister_driver(gb_tty_driver);
|
put_tty_driver(gb_tty_driver);
|
idr_destroy(&tty_minors);
|
}
|
|
static const struct gbphy_device_id gb_uart_id_table[] = {
|
{ GBPHY_PROTOCOL(GREYBUS_PROTOCOL_UART) },
|
{ },
|
};
|
MODULE_DEVICE_TABLE(gbphy, gb_uart_id_table);
|
|
static struct gbphy_driver uart_driver = {
|
.name = "uart",
|
.probe = gb_uart_probe,
|
.remove = gb_uart_remove,
|
.id_table = gb_uart_id_table,
|
};
|
|
static int gb_uart_driver_init(void)
|
{
|
int ret;
|
|
ret = gb_tty_init();
|
if (ret)
|
return ret;
|
|
ret = gb_gbphy_register(&uart_driver);
|
if (ret) {
|
gb_tty_exit();
|
return ret;
|
}
|
|
return 0;
|
}
|
module_init(gb_uart_driver_init);
|
|
static void gb_uart_driver_exit(void)
|
{
|
gb_gbphy_deregister(&uart_driver);
|
gb_tty_exit();
|
}
|
|
module_exit(gb_uart_driver_exit);
|
MODULE_LICENSE("GPL v2");
|
