diff options
Diffstat (limited to 'drivers/tty/serial/jsm/jsm_tty.c')
| -rw-r--r-- | drivers/tty/serial/jsm/jsm_tty.c | 823 |
1 files changed, 823 insertions, 0 deletions
diff --git a/drivers/tty/serial/jsm/jsm_tty.c b/drivers/tty/serial/jsm/jsm_tty.c new file mode 100644 index 000000000..8438454ca --- /dev/null +++ b/drivers/tty/serial/jsm/jsm_tty.c @@ -0,0 +1,823 @@ +// SPDX-License-Identifier: GPL-2.0+ +/************************************************************************ + * Copyright 2003 Digi International (www.digi.com) + * + * Copyright (C) 2004 IBM Corporation. All rights reserved. + * + * Contact Information: + * Scott H Kilau <Scott_Kilau@digi.com> + * Ananda Venkatarman <mansarov@us.ibm.com> + * Modifications: + * 01/19/06: changed jsm_input routine to use the dynamically allocated + * tty_buffer changes. Contributors: Scott Kilau and Ananda V. + ***********************************************************************/ +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/serial_reg.h> +#include <linux/delay.h> /* For udelay */ +#include <linux/pci.h> +#include <linux/slab.h> + +#include "jsm.h" + +static DECLARE_BITMAP(linemap, MAXLINES); + +static void jsm_carrier(struct jsm_channel *ch); + +static inline int jsm_get_mstat(struct jsm_channel *ch) +{ + unsigned char mstat; + int result; + + jsm_dbg(IOCTL, &ch->ch_bd->pci_dev, "start\n"); + + mstat = (ch->ch_mostat | ch->ch_mistat); + + result = 0; + + if (mstat & UART_MCR_DTR) + result |= TIOCM_DTR; + if (mstat & UART_MCR_RTS) + result |= TIOCM_RTS; + if (mstat & UART_MSR_CTS) + result |= TIOCM_CTS; + if (mstat & UART_MSR_DSR) + result |= TIOCM_DSR; + if (mstat & UART_MSR_RI) + result |= TIOCM_RI; + if (mstat & UART_MSR_DCD) + result |= TIOCM_CD; + + jsm_dbg(IOCTL, &ch->ch_bd->pci_dev, "finish\n"); + return result; +} + +static unsigned int jsm_tty_tx_empty(struct uart_port *port) +{ + return TIOCSER_TEMT; +} + +/* + * Return modem signals to ld. + */ +static unsigned int jsm_tty_get_mctrl(struct uart_port *port) +{ + int result; + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + + jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n"); + + result = jsm_get_mstat(channel); + + if (result < 0) + return -ENXIO; + + jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n"); + + return result; +} + +/* + * jsm_set_modem_info() + * + * Set modem signals, called by ld. + */ +static void jsm_tty_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + + jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n"); + + if (mctrl & TIOCM_RTS) + channel->ch_mostat |= UART_MCR_RTS; + else + channel->ch_mostat &= ~UART_MCR_RTS; + + if (mctrl & TIOCM_DTR) + channel->ch_mostat |= UART_MCR_DTR; + else + channel->ch_mostat &= ~UART_MCR_DTR; + + channel->ch_bd->bd_ops->assert_modem_signals(channel); + + jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n"); + udelay(10); +} + +/* + * jsm_tty_write() + * + * Take data from the user or kernel and send it out to the FEP. + * In here exists all the Transparent Print magic as well. + */ +static void jsm_tty_write(struct uart_port *port) +{ + struct jsm_channel *channel; + + channel = container_of(port, struct jsm_channel, uart_port); + channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel); +} + +static void jsm_tty_start_tx(struct uart_port *port) +{ + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + + jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n"); + + channel->ch_flags &= ~(CH_STOP); + jsm_tty_write(port); + + jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n"); +} + +static void jsm_tty_stop_tx(struct uart_port *port) +{ + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + + jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n"); + + channel->ch_flags |= (CH_STOP); + + jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n"); +} + +static void jsm_tty_send_xchar(struct uart_port *port, char ch) +{ + unsigned long lock_flags; + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + struct ktermios *termios; + + spin_lock_irqsave(&port->lock, lock_flags); + termios = &port->state->port.tty->termios; + if (ch == termios->c_cc[VSTART]) + channel->ch_bd->bd_ops->send_start_character(channel); + + if (ch == termios->c_cc[VSTOP]) + channel->ch_bd->bd_ops->send_stop_character(channel); + spin_unlock_irqrestore(&port->lock, lock_flags); +} + +static void jsm_tty_stop_rx(struct uart_port *port) +{ + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + + channel->ch_bd->bd_ops->disable_receiver(channel); +} + +static void jsm_tty_break(struct uart_port *port, int break_state) +{ + unsigned long lock_flags; + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + + spin_lock_irqsave(&port->lock, lock_flags); + if (break_state == -1) + channel->ch_bd->bd_ops->send_break(channel); + else + channel->ch_bd->bd_ops->clear_break(channel); + + spin_unlock_irqrestore(&port->lock, lock_flags); +} + +static int jsm_tty_open(struct uart_port *port) +{ + unsigned long lock_flags; + struct jsm_board *brd; + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + struct ktermios *termios; + + /* Get board pointer from our array of majors we have allocated */ + brd = channel->ch_bd; + + /* + * Allocate channel buffers for read/write/error. + * Set flag, so we don't get trounced on. + */ + channel->ch_flags |= (CH_OPENING); + + /* Drop locks, as malloc with GFP_KERNEL can sleep */ + + if (!channel->ch_rqueue) { + channel->ch_rqueue = kzalloc(RQUEUESIZE, GFP_KERNEL); + if (!channel->ch_rqueue) { + jsm_dbg(INIT, &channel->ch_bd->pci_dev, + "unable to allocate read queue buf\n"); + return -ENOMEM; + } + } + if (!channel->ch_equeue) { + channel->ch_equeue = kzalloc(EQUEUESIZE, GFP_KERNEL); + if (!channel->ch_equeue) { + jsm_dbg(INIT, &channel->ch_bd->pci_dev, + "unable to allocate error queue buf\n"); + return -ENOMEM; + } + } + + channel->ch_flags &= ~(CH_OPENING); + /* + * Initialize if neither terminal is open. + */ + jsm_dbg(OPEN, &channel->ch_bd->pci_dev, + "jsm_open: initializing channel in open...\n"); + + /* + * Flush input queues. + */ + channel->ch_r_head = channel->ch_r_tail = 0; + channel->ch_e_head = channel->ch_e_tail = 0; + + brd->bd_ops->flush_uart_write(channel); + brd->bd_ops->flush_uart_read(channel); + + channel->ch_flags = 0; + channel->ch_cached_lsr = 0; + channel->ch_stops_sent = 0; + + spin_lock_irqsave(&port->lock, lock_flags); + termios = &port->state->port.tty->termios; + channel->ch_c_cflag = termios->c_cflag; + channel->ch_c_iflag = termios->c_iflag; + channel->ch_c_oflag = termios->c_oflag; + channel->ch_c_lflag = termios->c_lflag; + channel->ch_startc = termios->c_cc[VSTART]; + channel->ch_stopc = termios->c_cc[VSTOP]; + + /* Tell UART to init itself */ + brd->bd_ops->uart_init(channel); + + /* + * Run param in case we changed anything + */ + brd->bd_ops->param(channel); + + jsm_carrier(channel); + + channel->ch_open_count++; + spin_unlock_irqrestore(&port->lock, lock_flags); + + jsm_dbg(OPEN, &channel->ch_bd->pci_dev, "finish\n"); + return 0; +} + +static void jsm_tty_close(struct uart_port *port) +{ + struct jsm_board *bd; + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + + jsm_dbg(CLOSE, &channel->ch_bd->pci_dev, "start\n"); + + bd = channel->ch_bd; + + channel->ch_flags &= ~(CH_STOPI); + + channel->ch_open_count--; + + /* + * If we have HUPCL set, lower DTR and RTS + */ + if (channel->ch_c_cflag & HUPCL) { + jsm_dbg(CLOSE, &channel->ch_bd->pci_dev, + "Close. HUPCL set, dropping DTR/RTS\n"); + + /* Drop RTS/DTR */ + channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS); + bd->bd_ops->assert_modem_signals(channel); + } + + /* Turn off UART interrupts for this port */ + channel->ch_bd->bd_ops->uart_off(channel); + + jsm_dbg(CLOSE, &channel->ch_bd->pci_dev, "finish\n"); +} + +static void jsm_tty_set_termios(struct uart_port *port, + struct ktermios *termios, + struct ktermios *old_termios) +{ + unsigned long lock_flags; + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + + spin_lock_irqsave(&port->lock, lock_flags); + channel->ch_c_cflag = termios->c_cflag; + channel->ch_c_iflag = termios->c_iflag; + channel->ch_c_oflag = termios->c_oflag; + channel->ch_c_lflag = termios->c_lflag; + channel->ch_startc = termios->c_cc[VSTART]; + channel->ch_stopc = termios->c_cc[VSTOP]; + + channel->ch_bd->bd_ops->param(channel); + jsm_carrier(channel); + spin_unlock_irqrestore(&port->lock, lock_flags); +} + +static const char *jsm_tty_type(struct uart_port *port) +{ + return "jsm"; +} + +static void jsm_tty_release_port(struct uart_port *port) +{ +} + +static int jsm_tty_request_port(struct uart_port *port) +{ + return 0; +} + +static void jsm_config_port(struct uart_port *port, int flags) +{ + port->type = PORT_JSM; +} + +static const struct uart_ops jsm_ops = { + .tx_empty = jsm_tty_tx_empty, + .set_mctrl = jsm_tty_set_mctrl, + .get_mctrl = jsm_tty_get_mctrl, + .stop_tx = jsm_tty_stop_tx, + .start_tx = jsm_tty_start_tx, + .send_xchar = jsm_tty_send_xchar, + .stop_rx = jsm_tty_stop_rx, + .break_ctl = jsm_tty_break, + .startup = jsm_tty_open, + .shutdown = jsm_tty_close, + .set_termios = jsm_tty_set_termios, + .type = jsm_tty_type, + .release_port = jsm_tty_release_port, + .request_port = jsm_tty_request_port, + .config_port = jsm_config_port, +}; + +/* + * jsm_tty_init() + * + * Init the tty subsystem. Called once per board after board has been + * downloaded and init'ed. + */ +int jsm_tty_init(struct jsm_board *brd) +{ + int i; + void __iomem *vaddr; + struct jsm_channel *ch; + + if (!brd) + return -ENXIO; + + jsm_dbg(INIT, &brd->pci_dev, "start\n"); + + /* + * Initialize board structure elements. + */ + + brd->nasync = brd->maxports; + + /* + * Allocate channel memory that might not have been allocated + * when the driver was first loaded. + */ + for (i = 0; i < brd->nasync; i++) { + if (!brd->channels[i]) { + + /* + * Okay to malloc with GFP_KERNEL, we are not at + * interrupt context, and there are no locks held. + */ + brd->channels[i] = kzalloc(sizeof(struct jsm_channel), GFP_KERNEL); + if (!brd->channels[i]) { + jsm_dbg(CORE, &brd->pci_dev, + "%s:%d Unable to allocate memory for channel struct\n", + __FILE__, __LINE__); + } + } + } + + ch = brd->channels[0]; + vaddr = brd->re_map_membase; + + /* Set up channel variables */ + for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) { + + if (!brd->channels[i]) + continue; + + spin_lock_init(&ch->ch_lock); + + if (brd->bd_uart_offset == 0x200) + ch->ch_neo_uart = vaddr + (brd->bd_uart_offset * i); + else + ch->ch_cls_uart = vaddr + (brd->bd_uart_offset * i); + + ch->ch_bd = brd; + ch->ch_portnum = i; + + /* .25 second delay */ + ch->ch_close_delay = 250; + + init_waitqueue_head(&ch->ch_flags_wait); + } + + jsm_dbg(INIT, &brd->pci_dev, "finish\n"); + return 0; +} + +int jsm_uart_port_init(struct jsm_board *brd) +{ + int i, rc; + unsigned int line; + + if (!brd) + return -ENXIO; + + jsm_dbg(INIT, &brd->pci_dev, "start\n"); + + /* + * Initialize board structure elements. + */ + + brd->nasync = brd->maxports; + + /* Set up channel variables */ + for (i = 0; i < brd->nasync; i++) { + + if (!brd->channels[i]) + continue; + + brd->channels[i]->uart_port.irq = brd->irq; + brd->channels[i]->uart_port.uartclk = 14745600; + brd->channels[i]->uart_port.type = PORT_JSM; + brd->channels[i]->uart_port.iotype = UPIO_MEM; + brd->channels[i]->uart_port.membase = brd->re_map_membase; + brd->channels[i]->uart_port.fifosize = 16; + brd->channels[i]->uart_port.ops = &jsm_ops; + line = find_first_zero_bit(linemap, MAXLINES); + if (line >= MAXLINES) { + printk(KERN_INFO "jsm: linemap is full, added device failed\n"); + continue; + } else + set_bit(line, linemap); + brd->channels[i]->uart_port.line = line; + rc = uart_add_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port); + if (rc) { + printk(KERN_INFO "jsm: Port %d failed. Aborting...\n", i); + return rc; + } else + printk(KERN_INFO "jsm: Port %d added\n", i); + } + + jsm_dbg(INIT, &brd->pci_dev, "finish\n"); + return 0; +} + +int jsm_remove_uart_port(struct jsm_board *brd) +{ + int i; + struct jsm_channel *ch; + + if (!brd) + return -ENXIO; + + jsm_dbg(INIT, &brd->pci_dev, "start\n"); + + /* + * Initialize board structure elements. + */ + + brd->nasync = brd->maxports; + + /* Set up channel variables */ + for (i = 0; i < brd->nasync; i++) { + + if (!brd->channels[i]) + continue; + + ch = brd->channels[i]; + + clear_bit(ch->uart_port.line, linemap); + uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port); + } + + jsm_dbg(INIT, &brd->pci_dev, "finish\n"); + return 0; +} + +void jsm_input(struct jsm_channel *ch) +{ + struct jsm_board *bd; + struct tty_struct *tp; + struct tty_port *port; + u32 rmask; + u16 head; + u16 tail; + int data_len; + unsigned long lock_flags; + int len = 0; + int s = 0; + int i = 0; + + jsm_dbg(READ, &ch->ch_bd->pci_dev, "start\n"); + + port = &ch->uart_port.state->port; + tp = port->tty; + + bd = ch->ch_bd; + if (!bd) + return; + + spin_lock_irqsave(&ch->ch_lock, lock_flags); + + /* + *Figure the number of characters in the buffer. + *Exit immediately if none. + */ + + rmask = RQUEUEMASK; + + head = ch->ch_r_head & rmask; + tail = ch->ch_r_tail & rmask; + + data_len = (head - tail) & rmask; + if (data_len == 0) { + spin_unlock_irqrestore(&ch->ch_lock, lock_flags); + return; + } + + jsm_dbg(READ, &ch->ch_bd->pci_dev, "start\n"); + + /* + *If the device is not open, or CREAD is off, flush + *input data and return immediately. + */ + if (!tp || !C_CREAD(tp)) { + + jsm_dbg(READ, &ch->ch_bd->pci_dev, + "input. dropping %d bytes on port %d...\n", + data_len, ch->ch_portnum); + ch->ch_r_head = tail; + + /* Force queue flow control to be released, if needed */ + jsm_check_queue_flow_control(ch); + + spin_unlock_irqrestore(&ch->ch_lock, lock_flags); + return; + } + + /* + * If we are throttled, simply don't read any data. + */ + if (ch->ch_flags & CH_STOPI) { + spin_unlock_irqrestore(&ch->ch_lock, lock_flags); + jsm_dbg(READ, &ch->ch_bd->pci_dev, + "Port %d throttled, not reading any data. head: %x tail: %x\n", + ch->ch_portnum, head, tail); + return; + } + + jsm_dbg(READ, &ch->ch_bd->pci_dev, "start 2\n"); + + len = tty_buffer_request_room(port, data_len); + + /* + * len now contains the most amount of data we can copy, + * bounded either by the flip buffer size or the amount + * of data the card actually has pending... + */ + while (len) { + s = ((head >= tail) ? head : RQUEUESIZE) - tail; + s = min(s, len); + + if (s <= 0) + break; + + /* + * If conditions are such that ld needs to see all + * UART errors, we will have to walk each character + * and error byte and send them to the buffer one at + * a time. + */ + + if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) { + for (i = 0; i < s; i++) { + /* + * Give the Linux ld the flags in the + * format it likes. + */ + if (*(ch->ch_equeue +tail +i) & UART_LSR_BI) + tty_insert_flip_char(port, *(ch->ch_rqueue +tail +i), TTY_BREAK); + else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE) + tty_insert_flip_char(port, *(ch->ch_rqueue +tail +i), TTY_PARITY); + else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE) + tty_insert_flip_char(port, *(ch->ch_rqueue +tail +i), TTY_FRAME); + else + tty_insert_flip_char(port, *(ch->ch_rqueue +tail +i), TTY_NORMAL); + } + } else { + tty_insert_flip_string(port, ch->ch_rqueue + tail, s); + } + tail += s; + len -= s; + /* Flip queue if needed */ + tail &= rmask; + } + + ch->ch_r_tail = tail & rmask; + ch->ch_e_tail = tail & rmask; + jsm_check_queue_flow_control(ch); + spin_unlock_irqrestore(&ch->ch_lock, lock_flags); + + /* Tell the tty layer its okay to "eat" the data now */ + tty_flip_buffer_push(port); + + jsm_dbg(IOCTL, &ch->ch_bd->pci_dev, "finish\n"); +} + +static void jsm_carrier(struct jsm_channel *ch) +{ + struct jsm_board *bd; + + int virt_carrier = 0; + int phys_carrier = 0; + + jsm_dbg(CARR, &ch->ch_bd->pci_dev, "start\n"); + + bd = ch->ch_bd; + if (!bd) + return; + + if (ch->ch_mistat & UART_MSR_DCD) { + jsm_dbg(CARR, &ch->ch_bd->pci_dev, "mistat: %x D_CD: %x\n", + ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD); + phys_carrier = 1; + } + + if (ch->ch_c_cflag & CLOCAL) + virt_carrier = 1; + + jsm_dbg(CARR, &ch->ch_bd->pci_dev, "DCD: physical: %d virt: %d\n", + phys_carrier, virt_carrier); + + /* + * Test for a VIRTUAL carrier transition to HIGH. + */ + if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) { + + /* + * When carrier rises, wake any threads waiting + * for carrier in the open routine. + */ + + jsm_dbg(CARR, &ch->ch_bd->pci_dev, "carrier: virt DCD rose\n"); + + if (waitqueue_active(&(ch->ch_flags_wait))) + wake_up_interruptible(&ch->ch_flags_wait); + } + + /* + * Test for a PHYSICAL carrier transition to HIGH. + */ + if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) { + + /* + * When carrier rises, wake any threads waiting + * for carrier in the open routine. + */ + + jsm_dbg(CARR, &ch->ch_bd->pci_dev, + "carrier: physical DCD rose\n"); + + if (waitqueue_active(&(ch->ch_flags_wait))) + wake_up_interruptible(&ch->ch_flags_wait); + } + + /* + * Test for a PHYSICAL transition to low, so long as we aren't + * currently ignoring physical transitions (which is what "virtual + * carrier" indicates). + * + * The transition of the virtual carrier to low really doesn't + * matter... it really only means "ignore carrier state", not + * "make pretend that carrier is there". + */ + if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0) + && (phys_carrier == 0)) { + /* + * When carrier drops: + * + * Drop carrier on all open units. + * + * Flush queues, waking up any task waiting in the + * line discipline. + * + * Send a hangup to the control terminal. + * + * Enable all select calls. + */ + if (waitqueue_active(&(ch->ch_flags_wait))) + wake_up_interruptible(&ch->ch_flags_wait); + } + + /* + * Make sure that our cached values reflect the current reality. + */ + if (virt_carrier == 1) + ch->ch_flags |= CH_FCAR; + else + ch->ch_flags &= ~CH_FCAR; + + if (phys_carrier == 1) + ch->ch_flags |= CH_CD; + else + ch->ch_flags &= ~CH_CD; +} + + +void jsm_check_queue_flow_control(struct jsm_channel *ch) +{ + struct board_ops *bd_ops = ch->ch_bd->bd_ops; + int qleft; + + /* Store how much space we have left in the queue */ + if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0) + qleft += RQUEUEMASK + 1; + + /* + * Check to see if we should enforce flow control on our queue because + * the ld (or user) isn't reading data out of our queue fast enuf. + * + * NOTE: This is done based on what the current flow control of the + * port is set for. + * + * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt. + * This will cause the UART's FIFO to back up, and force + * the RTS signal to be dropped. + * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to + * the other side, in hopes it will stop sending data to us. + * 3) NONE - Nothing we can do. We will simply drop any extra data + * that gets sent into us when the queue fills up. + */ + if (qleft < 256) { + /* HWFLOW */ + if (ch->ch_c_cflag & CRTSCTS) { + if (!(ch->ch_flags & CH_RECEIVER_OFF)) { + bd_ops->disable_receiver(ch); + ch->ch_flags |= (CH_RECEIVER_OFF); + jsm_dbg(READ, &ch->ch_bd->pci_dev, + "Internal queue hit hilevel mark (%d)! Turning off interrupts\n", + qleft); + } + } + /* SWFLOW */ + else if (ch->ch_c_iflag & IXOFF) { + if (ch->ch_stops_sent <= MAX_STOPS_SENT) { + bd_ops->send_stop_character(ch); + ch->ch_stops_sent++; + jsm_dbg(READ, &ch->ch_bd->pci_dev, + "Sending stop char! Times sent: %x\n", + ch->ch_stops_sent); + } + } + } + + /* + * Check to see if we should unenforce flow control because + * ld (or user) finally read enuf data out of our queue. + * + * NOTE: This is done based on what the current flow control of the + * port is set for. + * + * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt. + * This will cause the UART's FIFO to raise RTS back up, + * which will allow the other side to start sending data again. + * 2) SWFLOW (IXOFF) - Send a start character to + * the other side, so it will start sending data to us again. + * 3) NONE - Do nothing. Since we didn't do anything to turn off the + * other side, we don't need to do anything now. + */ + if (qleft > (RQUEUESIZE / 2)) { + /* HWFLOW */ + if (ch->ch_c_cflag & CRTSCTS) { + if (ch->ch_flags & CH_RECEIVER_OFF) { + bd_ops->enable_receiver(ch); + ch->ch_flags &= ~(CH_RECEIVER_OFF); + jsm_dbg(READ, &ch->ch_bd->pci_dev, + "Internal queue hit lowlevel mark (%d)! Turning on interrupts\n", + qleft); + } + } + /* SWFLOW */ + else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) { + ch->ch_stops_sent = 0; + bd_ops->send_start_character(ch); + jsm_dbg(READ, &ch->ch_bd->pci_dev, + "Sending start char!\n"); + } + } +} |