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author | Greg Kroah-Hartman <gregkh@suse.de> | 2011-01-13 20:10:18 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-01-13 20:10:18 (GMT) |
commit | ab4382d27412e7e3e7c936e8d50d8888dfac3df8 (patch) | |
tree | 51d96dea2431140358784b6b426715f37f74fd53 /drivers/tty/serial/nwpserial.c | |
parent | 728674a7e466628df2aeec6d11a2ae1ef968fb67 (diff) | |
download | linux-fsl-qoriq-ab4382d27412e7e3e7c936e8d50d8888dfac3df8.tar.xz |
tty: move drivers/serial/ to drivers/tty/serial/
The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.
This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/tty/serial/nwpserial.c')
-rw-r--r-- | drivers/tty/serial/nwpserial.c | 477 |
1 files changed, 477 insertions, 0 deletions
diff --git a/drivers/tty/serial/nwpserial.c b/drivers/tty/serial/nwpserial.c new file mode 100644 index 0000000..de17367 --- /dev/null +++ b/drivers/tty/serial/nwpserial.c @@ -0,0 +1,477 @@ +/* + * 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/console.h> +#include <linux/serial.h> +#include <linux/serial_reg.h> +#include <linux/serial_core.h> +#include <linux/tty.h> +#include <linux/irqreturn.h> +#include <linux/mutex.h> +#include <linux/of_platform.h> +#include <linux/of_device.h> +#include <linux/nwpserial.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_struct *tty = up->port.state->port.tty; + 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(tty, ch, TTY_NORMAL); + } while (dcr_read(up->dcr_host, UART_LSR) & UART_LSR_DR); + + tty_flip_buffer_push(tty); + 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, port); +} + +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_enable_ms(struct uart_port *port) +{ + /* 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, + .enable_ms = nwpserial_enable_ms, + .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 */ |