+++ /dev/null
-/*
- * Serial Port driver for a NWP uart device
- *
- * Copyright (C) 2008 IBM Corp., Benjamin Krill <ben@codiert.org>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- */
-#include <linux/init.h>
-#include <linux/export.h>
-#include <linux/console.h>
-#include <linux/serial.h>
-#include <linux/serial_reg.h>
-#include <linux/serial_core.h>
-#include <linux/tty.h>
-#include <linux/tty_flip.h>
-#include <linux/irqreturn.h>
-#include <linux/mutex.h>
-#include <linux/of_platform.h>
-#include <linux/of_device.h>
-#include <linux/nwpserial.h>
-#include <linux/delay.h>
-#include <asm/prom.h>
-#include <asm/dcr.h>
-
-#define NWPSERIAL_NR 2
-
-#define NWPSERIAL_STATUS_RXVALID 0x1
-#define NWPSERIAL_STATUS_TXFULL 0x2
-
-struct nwpserial_port {
- struct uart_port port;
- dcr_host_t dcr_host;
- unsigned int ier;
- unsigned int mcr;
-};
-
-static DEFINE_MUTEX(nwpserial_mutex);
-static struct nwpserial_port nwpserial_ports[NWPSERIAL_NR];
-
-static void wait_for_bits(struct nwpserial_port *up, int bits)
-{
- unsigned int status, tmout = 10000;
-
- /* Wait up to 10ms for the character(s) to be sent. */
- do {
- status = dcr_read(up->dcr_host, UART_LSR);
-
- if (--tmout == 0)
- break;
- udelay(1);
- } while ((status & bits) != bits);
-}
-
-#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL_CONSOLE
-static void nwpserial_console_putchar(struct uart_port *port, int c)
-{
- struct nwpserial_port *up;
- up = container_of(port, struct nwpserial_port, port);
- /* check if tx buffer is full */
- wait_for_bits(up, UART_LSR_THRE);
- dcr_write(up->dcr_host, UART_TX, c);
- up->port.icount.tx++;
-}
-
-static void
-nwpserial_console_write(struct console *co, const char *s, unsigned int count)
-{
- struct nwpserial_port *up = &nwpserial_ports[co->index];
- unsigned long flags;
- int locked = 1;
-
- if (oops_in_progress)
- locked = spin_trylock_irqsave(&up->port.lock, flags);
- else
- spin_lock_irqsave(&up->port.lock, flags);
-
- /* save and disable interrupt */
- up->ier = dcr_read(up->dcr_host, UART_IER);
- dcr_write(up->dcr_host, UART_IER, up->ier & ~UART_IER_RDI);
-
- uart_console_write(&up->port, s, count, nwpserial_console_putchar);
-
- /* wait for transmitter to become empty */
- while ((dcr_read(up->dcr_host, UART_LSR) & UART_LSR_THRE) == 0)
- cpu_relax();
-
- /* restore interrupt state */
- dcr_write(up->dcr_host, UART_IER, up->ier);
-
- if (locked)
- spin_unlock_irqrestore(&up->port.lock, flags);
-}
-
-static struct uart_driver nwpserial_reg;
-static struct console nwpserial_console = {
- .name = "ttySQ",
- .write = nwpserial_console_write,
- .device = uart_console_device,
- .flags = CON_PRINTBUFFER,
- .index = -1,
- .data = &nwpserial_reg,
-};
-#define NWPSERIAL_CONSOLE (&nwpserial_console)
-#else
-#define NWPSERIAL_CONSOLE NULL
-#endif /* CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL_CONSOLE */
-
-/**************************************************************************/
-
-static int nwpserial_request_port(struct uart_port *port)
-{
- return 0;
-}
-
-static void nwpserial_release_port(struct uart_port *port)
-{
- /* N/A */
-}
-
-static void nwpserial_config_port(struct uart_port *port, int flags)
-{
- port->type = PORT_NWPSERIAL;
-}
-
-static irqreturn_t nwpserial_interrupt(int irq, void *dev_id)
-{
- struct nwpserial_port *up = dev_id;
- struct tty_port *port = &up->port.state->port;
- irqreturn_t ret;
- unsigned int iir;
- unsigned char ch;
-
- spin_lock(&up->port.lock);
-
- /* check if the uart was the interrupt source. */
- iir = dcr_read(up->dcr_host, UART_IIR);
- if (!iir) {
- ret = IRQ_NONE;
- goto out;
- }
-
- do {
- up->port.icount.rx++;
- ch = dcr_read(up->dcr_host, UART_RX);
- if (up->port.ignore_status_mask != NWPSERIAL_STATUS_RXVALID)
- tty_insert_flip_char(port, ch, TTY_NORMAL);
- } while (dcr_read(up->dcr_host, UART_LSR) & UART_LSR_DR);
-
- spin_unlock(&up->port.lock);
- tty_flip_buffer_push(port);
- spin_lock(&up->port.lock);
-
- ret = IRQ_HANDLED;
-
- /* clear interrupt */
- dcr_write(up->dcr_host, UART_IIR, 1);
-out:
- spin_unlock(&up->port.lock);
- return ret;
-}
-
-static int nwpserial_startup(struct uart_port *port)
-{
- struct nwpserial_port *up;
- int err;
-
- up = container_of(port, struct nwpserial_port, port);
-
- /* disable flow control by default */
- up->mcr = dcr_read(up->dcr_host, UART_MCR) & ~UART_MCR_AFE;
- dcr_write(up->dcr_host, UART_MCR, up->mcr);
-
- /* register interrupt handler */
- err = request_irq(up->port.irq, nwpserial_interrupt,
- IRQF_SHARED, "nwpserial", up);
- if (err)
- return err;
-
- /* enable interrupts */
- up->ier = UART_IER_RDI;
- dcr_write(up->dcr_host, UART_IER, up->ier);
-
- /* enable receiving */
- up->port.ignore_status_mask &= ~NWPSERIAL_STATUS_RXVALID;
-
- return 0;
-}
-
-static void nwpserial_shutdown(struct uart_port *port)
-{
- struct nwpserial_port *up;
- up = container_of(port, struct nwpserial_port, port);
-
- /* disable receiving */
- up->port.ignore_status_mask |= NWPSERIAL_STATUS_RXVALID;
-
- /* disable interrupts from this port */
- up->ier = 0;
- dcr_write(up->dcr_host, UART_IER, up->ier);
-
- /* free irq */
- free_irq(up->port.irq, up);
-}
-
-static int nwpserial_verify_port(struct uart_port *port,
- struct serial_struct *ser)
-{
- return -EINVAL;
-}
-
-static const char *nwpserial_type(struct uart_port *port)
-{
- return port->type == PORT_NWPSERIAL ? "nwpserial" : NULL;
-}
-
-static void nwpserial_set_termios(struct uart_port *port,
- struct ktermios *termios, struct ktermios *old)
-{
- struct nwpserial_port *up;
- up = container_of(port, struct nwpserial_port, port);
-
- up->port.read_status_mask = NWPSERIAL_STATUS_RXVALID
- | NWPSERIAL_STATUS_TXFULL;
-
- up->port.ignore_status_mask = 0;
- /* ignore all characters if CREAD is not set */
- if ((termios->c_cflag & CREAD) == 0)
- up->port.ignore_status_mask |= NWPSERIAL_STATUS_RXVALID;
-
- /* Copy back the old hardware settings */
- if (old)
- tty_termios_copy_hw(termios, old);
-}
-
-static void nwpserial_break_ctl(struct uart_port *port, int ctl)
-{
- /* N/A */
-}
-
-static void nwpserial_stop_rx(struct uart_port *port)
-{
- struct nwpserial_port *up;
- up = container_of(port, struct nwpserial_port, port);
- /* don't forward any more data (like !CREAD) */
- up->port.ignore_status_mask = NWPSERIAL_STATUS_RXVALID;
-}
-
-static void nwpserial_putchar(struct nwpserial_port *up, unsigned char c)
-{
- /* check if tx buffer is full */
- wait_for_bits(up, UART_LSR_THRE);
- dcr_write(up->dcr_host, UART_TX, c);
- up->port.icount.tx++;
-}
-
-static void nwpserial_start_tx(struct uart_port *port)
-{
- struct nwpserial_port *up;
- struct circ_buf *xmit;
- up = container_of(port, struct nwpserial_port, port);
- xmit = &up->port.state->xmit;
-
- if (port->x_char) {
- nwpserial_putchar(up, up->port.x_char);
- port->x_char = 0;
- }
-
- while (!(uart_circ_empty(xmit) || uart_tx_stopped(&up->port))) {
- nwpserial_putchar(up, xmit->buf[xmit->tail]);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
- }
-}
-
-static unsigned int nwpserial_get_mctrl(struct uart_port *port)
-{
- return 0;
-}
-
-static void nwpserial_set_mctrl(struct uart_port *port, unsigned int mctrl)
-{
- /* N/A */
-}
-
-static void nwpserial_stop_tx(struct uart_port *port)
-{
- /* N/A */
-}
-
-static unsigned int nwpserial_tx_empty(struct uart_port *port)
-{
- struct nwpserial_port *up;
- unsigned long flags;
- int ret;
- up = container_of(port, struct nwpserial_port, port);
-
- spin_lock_irqsave(&up->port.lock, flags);
- ret = dcr_read(up->dcr_host, UART_LSR);
- spin_unlock_irqrestore(&up->port.lock, flags);
-
- return ret & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
-}
-
-static struct uart_ops nwpserial_pops = {
- .tx_empty = nwpserial_tx_empty,
- .set_mctrl = nwpserial_set_mctrl,
- .get_mctrl = nwpserial_get_mctrl,
- .stop_tx = nwpserial_stop_tx,
- .start_tx = nwpserial_start_tx,
- .stop_rx = nwpserial_stop_rx,
- .break_ctl = nwpserial_break_ctl,
- .startup = nwpserial_startup,
- .shutdown = nwpserial_shutdown,
- .set_termios = nwpserial_set_termios,
- .type = nwpserial_type,
- .release_port = nwpserial_release_port,
- .request_port = nwpserial_request_port,
- .config_port = nwpserial_config_port,
- .verify_port = nwpserial_verify_port,
-};
-
-static struct uart_driver nwpserial_reg = {
- .owner = THIS_MODULE,
- .driver_name = "nwpserial",
- .dev_name = "ttySQ",
- .major = TTY_MAJOR,
- .minor = 68,
- .nr = NWPSERIAL_NR,
- .cons = NWPSERIAL_CONSOLE,
-};
-
-int nwpserial_register_port(struct uart_port *port)
-{
- struct nwpserial_port *up = NULL;
- int ret = -1;
- int i;
- static int first = 1;
- int dcr_len;
- int dcr_base;
- struct device_node *dn;
-
- mutex_lock(&nwpserial_mutex);
-
- dn = port->dev->of_node;
- if (dn == NULL)
- goto out;
-
- /* get dcr base. */
- dcr_base = dcr_resource_start(dn, 0);
-
- /* find matching entry */
- for (i = 0; i < NWPSERIAL_NR; i++)
- if (nwpserial_ports[i].port.iobase == dcr_base) {
- up = &nwpserial_ports[i];
- break;
- }
-
- /* we didn't find a mtching entry, search for a free port */
- if (up == NULL)
- for (i = 0; i < NWPSERIAL_NR; i++)
- if (nwpserial_ports[i].port.type == PORT_UNKNOWN &&
- nwpserial_ports[i].port.iobase == 0) {
- up = &nwpserial_ports[i];
- break;
- }
-
- if (up == NULL) {
- ret = -EBUSY;
- goto out;
- }
-
- if (first)
- uart_register_driver(&nwpserial_reg);
- first = 0;
-
- up->port.membase = port->membase;
- up->port.irq = port->irq;
- up->port.uartclk = port->uartclk;
- up->port.fifosize = port->fifosize;
- up->port.regshift = port->regshift;
- up->port.iotype = port->iotype;
- up->port.flags = port->flags;
- up->port.mapbase = port->mapbase;
- up->port.private_data = port->private_data;
-
- if (port->dev)
- up->port.dev = port->dev;
-
- if (up->port.iobase != dcr_base) {
- up->port.ops = &nwpserial_pops;
- up->port.fifosize = 16;
-
- spin_lock_init(&up->port.lock);
-
- up->port.iobase = dcr_base;
- dcr_len = dcr_resource_len(dn, 0);
-
- up->dcr_host = dcr_map(dn, dcr_base, dcr_len);
- if (!DCR_MAP_OK(up->dcr_host)) {
- printk(KERN_ERR "Cannot map DCR resources for NWPSERIAL");
- goto out;
- }
- }
-
- ret = uart_add_one_port(&nwpserial_reg, &up->port);
- if (ret == 0)
- ret = up->port.line;
-
-out:
- mutex_unlock(&nwpserial_mutex);
-
- return ret;
-}
-EXPORT_SYMBOL(nwpserial_register_port);
-
-void nwpserial_unregister_port(int line)
-{
- struct nwpserial_port *up = &nwpserial_ports[line];
- mutex_lock(&nwpserial_mutex);
- uart_remove_one_port(&nwpserial_reg, &up->port);
-
- up->port.type = PORT_UNKNOWN;
-
- mutex_unlock(&nwpserial_mutex);
-}
-EXPORT_SYMBOL(nwpserial_unregister_port);
-
-#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL_CONSOLE
-static int __init nwpserial_console_init(void)
-{
- struct nwpserial_port *up = NULL;
- struct device_node *dn;
- const char *name;
- int dcr_base;
- int dcr_len;
- int i;
-
- /* search for a free port */
- for (i = 0; i < NWPSERIAL_NR; i++)
- if (nwpserial_ports[i].port.type == PORT_UNKNOWN) {
- up = &nwpserial_ports[i];
- break;
- }
-
- if (up == NULL)
- return -1;
-
- name = of_get_property(of_chosen, "linux,stdout-path", NULL);
- if (name == NULL)
- return -1;
-
- dn = of_find_node_by_path(name);
- if (!dn)
- return -1;
-
- spin_lock_init(&up->port.lock);
- up->port.ops = &nwpserial_pops;
- up->port.type = PORT_NWPSERIAL;
- up->port.fifosize = 16;
-
- dcr_base = dcr_resource_start(dn, 0);
- dcr_len = dcr_resource_len(dn, 0);
- up->port.iobase = dcr_base;
-
- up->dcr_host = dcr_map(dn, dcr_base, dcr_len);
- if (!DCR_MAP_OK(up->dcr_host)) {
- printk("Cannot map DCR resources for SERIAL");
- return -1;
- }
- register_console(&nwpserial_console);
- return 0;
-}
-console_initcall(nwpserial_console_init);
-#endif /* CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL_CONSOLE */
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