Re: [PATCH] tty: Add MOXA NPort Real TTY Driver
From: Greg Kroah-Hartman
Date: Tue Jul 14 2020 - 03:36:16 EST
On Tue, Jul 14, 2020 at 06:24:42AM +0000, Johnson CH Chen (éæå) wrote:
> This driver supports tty functions for all of MOXA's NPort series
> with v5.0. Using this driver, host part can use tty to connect NPort
> device server by ethernet.
>
> The following Moxa products are supported:
> * CN2600 Series
> * CN2500 Series
> * NPort DE Series
> * NPort 5000A-M12 Series
> * NPort 5100 Series
> * NPort 5200 Series
> * NPort 5400 Series
> * NPort 5600 Desktop Series
> * NPort 5600 Rackmount Series
> * NPort Wireless Series
> * NPort IA5000 Series
> * NPort 6000 Series
> * NPort S8000 Series
> * NPort S8455I Series
> * NPort S9000 Series
> * NE-4100 Series
> * MiiNePort Series
>
> Signed-off-by: Johnson Chen <johnsonch.chen@xxxxxxxx>
> Signed-off-by: Jason Chen <jason.chen@xxxxxxxx>
> Signed-off-by: Danny Lin <danny.lin@xxxxxxxx>
> Signed-off-by: Victor Yu <victor.yu@xxxxxxxx>
> ---
> drivers/tty/Kconfig | 11 +
> drivers/tty/Makefile | 1 +
> drivers/tty/npreal2.c | 3042 +++++++++++++++++++++++++++++++++++++++++
> drivers/tty/npreal2.h | 140 ++
> 4 files changed, 3194 insertions(+)
> create mode 100644 drivers/tty/npreal2.c
> create mode 100644 drivers/tty/npreal2.h
>
> diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
> index 93fd984eb2f5..79b545269b71 100644
> --- a/drivers/tty/Kconfig
> +++ b/drivers/tty/Kconfig
> @@ -259,6 +259,17 @@ config MOXA_SMARTIO
> This driver can also be built as a module. The module will be called
> mxser. If you want to do that, say M here.
>
> +config MOXA_NPORT_REAL_TTY
> + tristate "Moxa NPort Real TTY support v5.0"
> + help
> + Say Y here if you have a Moxa NPort serial device server.
> +
> + The purpose of this driver is to map NPort serial port to host tty
> + port. Using this driver, you can use NPort serial port as local tty port.
> +
> + This driver can also be built as a module. The module will be called
> + npreal2 by setting M.
> +
> config SYNCLINK
> tristate "Microgate SyncLink card support"
> depends on SERIAL_NONSTANDARD && PCI && ISA_DMA_API
> diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
> index 020b1cd9294f..6d07985d6962 100644
> --- a/drivers/tty/Makefile
> +++ b/drivers/tty/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_CYCLADES) += cyclades.o
> obj-$(CONFIG_ISI) += isicom.o
> obj-$(CONFIG_MOXA_INTELLIO) += moxa.o
> obj-$(CONFIG_MOXA_SMARTIO) += mxser.o
> +obj-$(CONFIG_MOXA_NPORT_REAL_TTY) += npreal2.o
> obj-$(CONFIG_NOZOMI) += nozomi.o
> obj-$(CONFIG_NULL_TTY) += ttynull.o
> obj-$(CONFIG_ROCKETPORT) += rocket.o
> diff --git a/drivers/tty/npreal2.c b/drivers/tty/npreal2.c
> new file mode 100644
> index 000000000000..65c773420755
> --- /dev/null
> +++ b/drivers/tty/npreal2.c
> @@ -0,0 +1,3042 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * npreal2.c -- MOXA NPort Server family Real TTY driver.
> + *
> + * Copyright (c) 1999-2020 Moxa Technologies (support@xxxxxxxx)
> + *
> + * Supports the following Moxa Product:
> + * CN2600 Series
> + * CN2500 Series
> + * NPort DE Series
> + * NPort 5000A-M12 Series
> + * NPort 5100 Series
> + * NPort 5200 Series
> + * NPort 5400 Series
> + * NPort 5600 Desktop Series
> + * NPort 5600 Rackmount Series
> + * NPort Wireless Series
> + * NPort IA5000 Series
> + * NPort 6000 Series
> + * NPort S8000 Series
> + * NPort S8455I Series
> + * NPort S9000 Series
> + * NE-4100 Series
> + * MiiNePort Series
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/errno.h>
> +#include <linux/fcntl.h>
> +#include <linux/version.h>
> +#include <linux/init.h>
> +#include <linux/ioport.h>
> +#include <linux/interrupt.h>
> +#include <linux/major.h>
> +#include <linux/mm.h>
> +#include <linux/module.h>
> +#include <linux/ptrace.h>
> +#include <linux/poll.h>
> +#include <linux/proc_fs.h>
> +#include <linux/uaccess.h>
> +#include <linux/serial.h>
> +#include <linux/serial_reg.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/signal.h>
> +#include <linux/sched.h>
> +#include <linux/tty.h>
> +#include <linux/tty_flip.h>
> +#include <linux/timer.h>
> +#include "npreal2.h"
> +
> +static int ttymajor = NPREALMAJOR;
> +static int verbose = 1;
> +
> +MODULE_AUTHOR("<support@xxxxxxxx>");
> +MODULE_DESCRIPTION("MOXA Async/NPort Server Family Real TTY Driver");
> +module_param(ttymajor, int, 0);
> +module_param(verbose, int, 0644);
> +MODULE_VERSION(NPREAL_VERSION);
> +MODULE_LICENSE("GPL");
> +
> +struct server_setting_struct {
> + int32_t server_type;
> + int32_t disable_fifo;
> +};
> +
> +struct npreal_struct {
> + struct tty_port ttyPort;
> + struct work_struct tqueue;
> + struct work_struct process_flip_tqueue;
> + struct ktermios normal_termios;
> + struct ktermios callout_termios;
> + /* kernel counters for the 4 input interrupts */
> + struct async_icount icount;
> + struct semaphore rx_semaphore;
> + struct nd_struct *net_node;
> + struct tty_struct *tty;
> + struct pid *session;
> + struct pid *pgrp;
> + wait_queue_head_t open_wait;
> + wait_queue_head_t close_wait;
> + wait_queue_head_t delta_msr_wait;
> + unsigned long baud_base;
> + unsigned long event;
> + unsigned short closing_wait;
> + int port;
> + int flags;
> + int type; /* UART type */
> + int xmit_fifo_size;
> + int custom_divisor;
> + int x_char; /* xon/xoff character */
> + int close_delay;
> + int modem_control; /* Modem control register */
> + int modem_status; /* Line status */
> + int count; /* # of fd on device */
> + int xmit_head;
> + int xmit_tail;
> + int xmit_cnt;
> + unsigned char *xmit_buf;
> +
> + /*
> + * We use spin_lock_irqsave instead of semaphonre here.
> + * Reason: When we use pppd to dialout via Real TTY driver,
> + * some driver functions, such as npreal_write(), would be
> + * invoked under interrpute mode which causes warning in
> + * down/up tx_semaphore.
> + */
> + spinlock_t tx_lock;
> +};
> +
> +struct nd_struct {
> + struct semaphore cmd_semaphore;
> + struct proc_dir_entry *node_entry;
> + struct npreal_struct *tty_node;
> + struct semaphore semaphore;
> + wait_queue_head_t initialize_wait;
> + wait_queue_head_t select_in_wait;
> + wait_queue_head_t select_out_wait;
> + wait_queue_head_t select_ex_wait;
> + wait_queue_head_t cmd_rsp_wait;
> + int32_t server_type;
> + int do_session_recovery_len;
> + int cmd_rsp_flag;
> + int tx_ready;
> + int rx_ready;
> + int cmd_ready;
> + int wait_oqueue_responsed;
> + int oqueue;
> + int rsp_length;
> + unsigned long flag;
> + unsigned char cmd_buffer[84];
> + unsigned char rsp_buffer[84];
You seem to have two "static" buffers here, for your device, that you
semi-randomly write to all over the place, but I can't find any locking
or coordination between things that prevents multiple commands from not
just overwritting each other.
Also, how does the data get sent to the hardware at all? I see
cmd_buffer[] being written to, but what reads from it and how does the
hardware get the data?
What am I missing here?
thanks,
greg k-h