613 lines
15 KiB
C
613 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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** mux.c:
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** serial driver for the Mux console found in some PA-RISC servers.
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**
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** (c) Copyright 2002 Ryan Bradetich
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** (c) Copyright 2002 Hewlett-Packard Company
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**
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** This Driver currently only supports the console (port 0) on the MUX.
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** Additional work will be needed on this driver to enable the full
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** functionality of the MUX.
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**
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*/
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#include <linux/module.h>
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#include <linux/ioport.h>
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#include <linux/init.h>
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#include <linux/serial.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#include <linux/console.h>
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#include <linux/delay.h> /* for udelay */
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#include <linux/device.h>
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#include <asm/io.h>
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#include <asm/irq.h>
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#include <asm/parisc-device.h>
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#if defined(CONFIG_SERIAL_MUX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
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#include <linux/sysrq.h>
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#define SUPPORT_SYSRQ
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#endif
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#include <linux/serial_core.h>
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#define MUX_OFFSET 0x800
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#define MUX_LINE_OFFSET 0x80
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#define MUX_FIFO_SIZE 255
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#define MUX_POLL_DELAY (30 * HZ / 1000)
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#define IO_DATA_REG_OFFSET 0x3c
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#define IO_DCOUNT_REG_OFFSET 0x40
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#define MUX_EOFIFO(status) ((status & 0xF000) == 0xF000)
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#define MUX_STATUS(status) ((status & 0xF000) == 0x8000)
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#define MUX_BREAK(status) ((status & 0xF000) == 0x2000)
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#define MUX_NR 256
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static unsigned int port_cnt __read_mostly;
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struct mux_port {
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struct uart_port port;
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int enabled;
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};
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static struct mux_port mux_ports[MUX_NR];
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static struct uart_driver mux_driver = {
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.owner = THIS_MODULE,
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.driver_name = "ttyB",
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.dev_name = "ttyB",
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.major = MUX_MAJOR,
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.minor = 0,
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.nr = MUX_NR,
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};
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static struct timer_list mux_timer;
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#define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + IO_DATA_REG_OFFSET)
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#define UART_GET_FIFO_CNT(p) __raw_readl((p)->membase + IO_DCOUNT_REG_OFFSET)
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/**
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* get_mux_port_count - Get the number of available ports on the Mux.
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* @dev: The parisc device.
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*
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* This function is used to determine the number of ports the Mux
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* supports. The IODC data reports the number of ports the Mux
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* can support, but there are cases where not all the Mux ports
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* are connected. This function can override the IODC and
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* return the true port count.
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*/
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static int __init get_mux_port_count(struct parisc_device *dev)
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{
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int status;
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u8 iodc_data[32];
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unsigned long bytecnt;
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/* If this is the built-in Mux for the K-Class (Eole CAP/MUX),
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* we only need to allocate resources for 1 port since the
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* other 7 ports are not connected.
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*/
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if(dev->id.hversion == 0x15)
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return 1;
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status = pdc_iodc_read(&bytecnt, dev->hpa.start, 0, iodc_data, 32);
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BUG_ON(status != PDC_OK);
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/* Return the number of ports specified in the iodc data. */
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return ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8;
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}
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/**
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* mux_tx_empty - Check if the transmitter fifo is empty.
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* @port: Ptr to the uart_port.
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*
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* This function test if the transmitter fifo for the port
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* described by 'port' is empty. If it is empty, this function
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* should return TIOCSER_TEMT, otherwise return 0.
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*/
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static unsigned int mux_tx_empty(struct uart_port *port)
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{
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return UART_GET_FIFO_CNT(port) ? 0 : TIOCSER_TEMT;
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}
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/**
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* mux_set_mctrl - Set the current state of the modem control inputs.
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* @ports: Ptr to the uart_port.
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* @mctrl: Modem control bits.
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*
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* The Serial MUX does not support CTS, DCD or DSR so this function
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* is ignored.
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*/
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static void mux_set_mctrl(struct uart_port *port, unsigned int mctrl)
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{
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}
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/**
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* mux_get_mctrl - Returns the current state of modem control inputs.
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* @port: Ptr to the uart_port.
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*
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* The Serial MUX does not support CTS, DCD or DSR so these lines are
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* treated as permanently active.
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*/
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static unsigned int mux_get_mctrl(struct uart_port *port)
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{
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return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
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}
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/**
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* mux_stop_tx - Stop transmitting characters.
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* @port: Ptr to the uart_port.
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*
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* The Serial MUX does not support this function.
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*/
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static void mux_stop_tx(struct uart_port *port)
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{
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}
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/**
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* mux_start_tx - Start transmitting characters.
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* @port: Ptr to the uart_port.
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*
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* The Serial Mux does not support this function.
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*/
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static void mux_start_tx(struct uart_port *port)
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{
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}
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/**
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* mux_stop_rx - Stop receiving characters.
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* @port: Ptr to the uart_port.
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*
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* The Serial Mux does not support this function.
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*/
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static void mux_stop_rx(struct uart_port *port)
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{
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}
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/**
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* mux_break_ctl - Control the transmitssion of a break signal.
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* @port: Ptr to the uart_port.
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* @break_state: Raise/Lower the break signal.
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*
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* The Serial Mux does not support this function.
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*/
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static void mux_break_ctl(struct uart_port *port, int break_state)
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{
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}
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/**
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* mux_write - Write chars to the mux fifo.
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* @port: Ptr to the uart_port.
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*
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* This function writes all the data from the uart buffer to
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* the mux fifo.
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*/
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static void mux_write(struct uart_port *port)
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{
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int count;
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struct circ_buf *xmit = &port->state->xmit;
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if(port->x_char) {
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UART_PUT_CHAR(port, port->x_char);
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port->icount.tx++;
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port->x_char = 0;
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return;
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}
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if(uart_circ_empty(xmit) || uart_tx_stopped(port)) {
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mux_stop_tx(port);
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return;
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}
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count = (port->fifosize) - UART_GET_FIFO_CNT(port);
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do {
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UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
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xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
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port->icount.tx++;
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if(uart_circ_empty(xmit))
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break;
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} while(--count > 0);
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while(UART_GET_FIFO_CNT(port))
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udelay(1);
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if(uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
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uart_write_wakeup(port);
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if (uart_circ_empty(xmit))
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mux_stop_tx(port);
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}
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/**
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* mux_read - Read chars from the mux fifo.
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* @port: Ptr to the uart_port.
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*
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* This reads all available data from the mux's fifo and pushes
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* the data to the tty layer.
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*/
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static void mux_read(struct uart_port *port)
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{
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struct tty_port *tport = &port->state->port;
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int data;
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__u32 start_count = port->icount.rx;
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while(1) {
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data = __raw_readl(port->membase + IO_DATA_REG_OFFSET);
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if (MUX_STATUS(data))
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continue;
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if (MUX_EOFIFO(data))
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break;
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port->icount.rx++;
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if (MUX_BREAK(data)) {
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port->icount.brk++;
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if(uart_handle_break(port))
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continue;
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}
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if (uart_handle_sysrq_char(port, data & 0xffu))
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continue;
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tty_insert_flip_char(tport, data & 0xFF, TTY_NORMAL);
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}
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if (start_count != port->icount.rx)
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tty_flip_buffer_push(tport);
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}
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/**
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* mux_startup - Initialize the port.
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* @port: Ptr to the uart_port.
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*
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* Grab any resources needed for this port and start the
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* mux timer.
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*/
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static int mux_startup(struct uart_port *port)
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{
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mux_ports[port->line].enabled = 1;
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return 0;
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}
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/**
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* mux_shutdown - Disable the port.
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* @port: Ptr to the uart_port.
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*
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* Release any resources needed for the port.
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*/
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static void mux_shutdown(struct uart_port *port)
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{
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mux_ports[port->line].enabled = 0;
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}
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/**
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* mux_set_termios - Chane port parameters.
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* @port: Ptr to the uart_port.
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* @termios: new termios settings.
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* @old: old termios settings.
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*
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* The Serial Mux does not support this function.
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*/
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static void
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mux_set_termios(struct uart_port *port, struct ktermios *termios,
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struct ktermios *old)
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{
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}
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/**
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* mux_type - Describe the port.
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* @port: Ptr to the uart_port.
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*
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* Return a pointer to a string constant describing the
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* specified port.
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*/
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static const char *mux_type(struct uart_port *port)
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{
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return "Mux";
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}
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/**
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* mux_release_port - Release memory and IO regions.
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* @port: Ptr to the uart_port.
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*
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* Release any memory and IO region resources currently in use by
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* the port.
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*/
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static void mux_release_port(struct uart_port *port)
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{
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}
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/**
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* mux_request_port - Request memory and IO regions.
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* @port: Ptr to the uart_port.
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*
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* Request any memory and IO region resources required by the port.
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* If any fail, no resources should be registered when this function
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* returns, and it should return -EBUSY on failure.
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*/
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static int mux_request_port(struct uart_port *port)
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{
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return 0;
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}
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/**
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* mux_config_port - Perform port autoconfiguration.
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* @port: Ptr to the uart_port.
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* @type: Bitmask of required configurations.
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*
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* Perform any autoconfiguration steps for the port. This function is
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* called if the UPF_BOOT_AUTOCONF flag is specified for the port.
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* [Note: This is required for now because of a bug in the Serial core.
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* rmk has already submitted a patch to linus, should be available for
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* 2.5.47.]
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*/
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static void mux_config_port(struct uart_port *port, int type)
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{
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port->type = PORT_MUX;
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}
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/**
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* mux_verify_port - Verify the port information.
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* @port: Ptr to the uart_port.
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* @ser: Ptr to the serial information.
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*
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* Verify the new serial port information contained within serinfo is
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* suitable for this port type.
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*/
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static int mux_verify_port(struct uart_port *port, struct serial_struct *ser)
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{
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if(port->membase == NULL)
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return -EINVAL;
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return 0;
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}
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/**
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* mux_drv_poll - Mux poll function.
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* @unused: Unused variable
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*
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* This function periodically polls the Serial MUX to check for new data.
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*/
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static void mux_poll(struct timer_list *unused)
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{
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int i;
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for(i = 0; i < port_cnt; ++i) {
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if(!mux_ports[i].enabled)
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continue;
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mux_read(&mux_ports[i].port);
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mux_write(&mux_ports[i].port);
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}
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mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
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}
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#ifdef CONFIG_SERIAL_MUX_CONSOLE
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static void mux_console_write(struct console *co, const char *s, unsigned count)
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{
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/* Wait until the FIFO drains. */
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while(UART_GET_FIFO_CNT(&mux_ports[0].port))
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udelay(1);
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while(count--) {
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if(*s == '\n') {
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UART_PUT_CHAR(&mux_ports[0].port, '\r');
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}
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UART_PUT_CHAR(&mux_ports[0].port, *s++);
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}
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}
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static int mux_console_setup(struct console *co, char *options)
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{
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return 0;
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}
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static struct console mux_console = {
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.name = "ttyB",
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.write = mux_console_write,
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.device = uart_console_device,
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.setup = mux_console_setup,
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.flags = CON_ENABLED | CON_PRINTBUFFER,
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.index = 0,
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.data = &mux_driver,
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};
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#define MUX_CONSOLE &mux_console
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#else
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#define MUX_CONSOLE NULL
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#endif
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static const struct uart_ops mux_pops = {
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.tx_empty = mux_tx_empty,
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.set_mctrl = mux_set_mctrl,
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.get_mctrl = mux_get_mctrl,
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.stop_tx = mux_stop_tx,
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.start_tx = mux_start_tx,
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.stop_rx = mux_stop_rx,
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.break_ctl = mux_break_ctl,
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.startup = mux_startup,
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.shutdown = mux_shutdown,
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.set_termios = mux_set_termios,
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.type = mux_type,
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.release_port = mux_release_port,
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.request_port = mux_request_port,
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.config_port = mux_config_port,
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.verify_port = mux_verify_port,
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};
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/**
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* mux_probe - Determine if the Serial Mux should claim this device.
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* @dev: The parisc device.
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*
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* Deterimine if the Serial Mux should claim this chip (return 0)
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* or not (return 1).
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*/
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static int __init mux_probe(struct parisc_device *dev)
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{
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int i, status;
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int port_count = get_mux_port_count(dev);
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printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.6\n", port_count);
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dev_set_drvdata(&dev->dev, (void *)(long)port_count);
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request_mem_region(dev->hpa.start + MUX_OFFSET,
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port_count * MUX_LINE_OFFSET, "Mux");
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if(!port_cnt) {
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mux_driver.cons = MUX_CONSOLE;
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status = uart_register_driver(&mux_driver);
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if(status) {
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printk(KERN_ERR "Serial mux: Unable to register driver.\n");
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return 1;
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}
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}
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for(i = 0; i < port_count; ++i, ++port_cnt) {
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struct uart_port *port = &mux_ports[port_cnt].port;
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port->iobase = 0;
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port->mapbase = dev->hpa.start + MUX_OFFSET +
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(i * MUX_LINE_OFFSET);
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port->membase = ioremap_nocache(port->mapbase, MUX_LINE_OFFSET);
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port->iotype = UPIO_MEM;
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port->type = PORT_MUX;
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port->irq = 0;
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port->uartclk = 0;
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port->fifosize = MUX_FIFO_SIZE;
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port->ops = &mux_pops;
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port->flags = UPF_BOOT_AUTOCONF;
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port->line = port_cnt;
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/* The port->timeout needs to match what is present in
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* uart_wait_until_sent in serial_core.c. Otherwise
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* the time spent in msleep_interruptable will be very
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* long, causing the appearance of a console hang.
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*/
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port->timeout = HZ / 50;
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spin_lock_init(&port->lock);
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status = uart_add_one_port(&mux_driver, port);
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BUG_ON(status);
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}
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return 0;
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}
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static int __exit mux_remove(struct parisc_device *dev)
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{
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int i, j;
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int port_count = (long)dev_get_drvdata(&dev->dev);
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/* Find Port 0 for this card in the mux_ports list. */
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for(i = 0; i < port_cnt; ++i) {
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if(mux_ports[i].port.mapbase == dev->hpa.start + MUX_OFFSET)
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break;
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}
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BUG_ON(i + port_count > port_cnt);
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/* Release the resources associated with each port on the device. */
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for(j = 0; j < port_count; ++j, ++i) {
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struct uart_port *port = &mux_ports[i].port;
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uart_remove_one_port(&mux_driver, port);
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if(port->membase)
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iounmap(port->membase);
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}
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release_mem_region(dev->hpa.start + MUX_OFFSET, port_count * MUX_LINE_OFFSET);
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return 0;
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}
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/* Hack. This idea was taken from the 8250_gsc.c on how to properly order
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* the serial port detection in the proper order. The idea is we always
|
|
* want the builtin mux to be detected before addin mux cards, so we
|
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* specifically probe for the builtin mux cards first.
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|
*
|
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* This table only contains the parisc_device_id of known builtin mux
|
|
* devices. All other mux cards will be detected by the generic mux_tbl.
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*/
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static const struct parisc_device_id builtin_mux_tbl[] __initconst = {
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{ HPHW_A_DIRECT, HVERSION_REV_ANY_ID, 0x15, 0x0000D }, /* All K-class */
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|
{ HPHW_A_DIRECT, HVERSION_REV_ANY_ID, 0x44, 0x0000D }, /* E35, E45, and E55 */
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|
{ 0, }
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|
};
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|
|
|
static const struct parisc_device_id mux_tbl[] __initconst = {
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|
{ HPHW_A_DIRECT, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0000D },
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|
{ 0, }
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|
};
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|
|
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MODULE_DEVICE_TABLE(parisc, builtin_mux_tbl);
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|
MODULE_DEVICE_TABLE(parisc, mux_tbl);
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|
|
|
static struct parisc_driver builtin_serial_mux_driver __refdata = {
|
|
.name = "builtin_serial_mux",
|
|
.id_table = builtin_mux_tbl,
|
|
.probe = mux_probe,
|
|
.remove = __exit_p(mux_remove),
|
|
};
|
|
|
|
static struct parisc_driver serial_mux_driver __refdata = {
|
|
.name = "serial_mux",
|
|
.id_table = mux_tbl,
|
|
.probe = mux_probe,
|
|
.remove = __exit_p(mux_remove),
|
|
};
|
|
|
|
/**
|
|
* mux_init - Serial MUX initialization procedure.
|
|
*
|
|
* Register the Serial MUX driver.
|
|
*/
|
|
static int __init mux_init(void)
|
|
{
|
|
register_parisc_driver(&builtin_serial_mux_driver);
|
|
register_parisc_driver(&serial_mux_driver);
|
|
|
|
if(port_cnt > 0) {
|
|
/* Start the Mux timer */
|
|
timer_setup(&mux_timer, mux_poll, 0);
|
|
mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
|
|
|
|
#ifdef CONFIG_SERIAL_MUX_CONSOLE
|
|
register_console(&mux_console);
|
|
#endif
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* mux_exit - Serial MUX cleanup procedure.
|
|
*
|
|
* Unregister the Serial MUX driver from the tty layer.
|
|
*/
|
|
static void __exit mux_exit(void)
|
|
{
|
|
/* Delete the Mux timer. */
|
|
if(port_cnt > 0) {
|
|
del_timer_sync(&mux_timer);
|
|
#ifdef CONFIG_SERIAL_MUX_CONSOLE
|
|
unregister_console(&mux_console);
|
|
#endif
|
|
}
|
|
|
|
unregister_parisc_driver(&builtin_serial_mux_driver);
|
|
unregister_parisc_driver(&serial_mux_driver);
|
|
uart_unregister_driver(&mux_driver);
|
|
}
|
|
|
|
module_init(mux_init);
|
|
module_exit(mux_exit);
|
|
|
|
MODULE_AUTHOR("Ryan Bradetich");
|
|
MODULE_DESCRIPTION("Serial MUX driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_CHARDEV_MAJOR(MUX_MAJOR);
|