source: mainline/kernel/genarch/src/kbd/ns16550.c@ af75db9

/*
 * Copyright (c) 2001-2006 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup genarch 
 * @{
 */
/**
 * @file
 * @brief       NS 16550 serial port / keyboard driver.
 */

#include <genarch/kbd/ns16550.h>
#include <genarch/kbd/key.h>
#include <genarch/kbd/scanc.h>
#include <genarch/kbd/scanc_sun.h>
#include <arch/drivers/kbd.h>
#include <ddi/irq.h>
#include <ipc/irq.h>
#include <cpu.h>
#include <arch/asm.h>
#include <arch.h>
#include <console/chardev.h>
#include <console/console.h>
#include <interrupt.h>
#include <arch/interrupt.h>
#include <sysinfo/sysinfo.h>
#include <synch/spinlock.h>

#define LSR_DATA_READY  0x01

/** Structure representing the ns16550. */
static ns16550_t ns16550;

/** Structure for ns16550's IRQ. */
static irq_t ns16550_irq;

/*
 * These codes read from ns16550 data register are silently ignored.
 */
#define IGNORE_CODE     0x7f            /* all keys up */

static void ns16550_suspend(chardev_t *);
static void ns16550_resume(chardev_t *);

static chardev_operations_t ops = {
        .suspend = ns16550_suspend,
        .resume = ns16550_resume,
        .read = ns16550_key_read
};

void ns16550_interrupt(void);

/** Initialize keyboard and service interrupts using kernel routine */
void ns16550_grab(void)
{
        ipl_t ipl = interrupts_disable();

        ns16550_ier_write(&ns16550, IER_ERBFI);         /* enable receiver interrupt */
        
        while (ns16550_lsr_read(&ns16550) & LSR_DATA_READY)
                (void) ns16550_rbr_read(&ns16550);

        spinlock_lock(&ns16550_irq.lock);
        ns16550_irq.notif_cfg.notify = false;
        spinlock_unlock(&ns16550_irq.lock);
        interrupts_restore(ipl);
}

/** Resume the former interrupt vector */
void ns16550_release(void)
{
        ipl_t ipl = interrupts_disable();
        spinlock_lock(&ns16550_irq.lock);
        if (ns16550_irq.notif_cfg.answerbox)
                ns16550_irq.notif_cfg.notify = true;
        spinlock_unlock(&ns16550_irq.lock);
        interrupts_restore(ipl);
}

/** Initialize ns16550.
 *
 * @param devno         Device number.
 * @param port          Virtual/IO address of device's registers.
 * @param inr           Interrupt number.
 * @param cir           Clear interrupt function.
 * @param cir_arg       First argument to cir.
 */
void
ns16550_init(devno_t devno, ioport_t port, inr_t inr, cir_t cir, void *cir_arg)
{
        chardev_initialize("ns16550_kbd", &kbrd, &ops);
        stdin = &kbrd;
        
        ns16550.devno = devno;
        ns16550.io_port = port;
        
        irq_initialize(&ns16550_irq);
        ns16550_irq.devno = devno;
        ns16550_irq.inr = inr;
        ns16550_irq.claim = ns16550_claim;
        ns16550_irq.handler = ns16550_irq_handler;
        ns16550_irq.cir = cir;
        ns16550_irq.cir_arg = cir_arg;
        irq_register(&ns16550_irq);
        
        while ((ns16550_lsr_read(&ns16550) & LSR_DATA_READY)) 
                ns16550_rbr_read(&ns16550);
        
        sysinfo_set_item_val("kbd", NULL, true);
        sysinfo_set_item_val("kbd.type", NULL, KBD_NS16550);
        sysinfo_set_item_val("kbd.devno", NULL, devno);
        sysinfo_set_item_val("kbd.inr", NULL, inr);
        sysinfo_set_item_val("kbd.address.virtual", NULL, port);
        sysinfo_set_item_val("kbd.port", NULL, port);
        
#ifdef CONFIG_NS16550_INTERRUPT_DRIVEN
        /* Enable interrupts */
        ns16550_ier_write(&ns16550, IER_ERBFI);
        ns16550_mcr_write(&ns16550, MCR_OUT2);
#endif
        
        uint8_t c;
        // This switches rbr & ier to mode when accept baudrate constant
        c = ns16550_lcr_read(&ns16550);
        ns16550_lcr_write(&ns16550, 0x80 | c);
        ns16550_rbr_write(&ns16550, 0x0c);
        ns16550_ier_write(&ns16550, 0x00);
        ns16550_lcr_write(&ns16550, c);
        
        ns16550_grab();
}

/** Process ns16550 interrupt. */
void ns16550_interrupt(void)
{
        ns16550_poll();
}

/* Called from getc(). */
void ns16550_resume(chardev_t *d)
{
}

/* Called from getc(). */
void ns16550_suspend(chardev_t *d)
{
}


char ns16550_key_read(chardev_t *d)
{
        char ch;        

        while(!(ch = active_read_buff_read())) {
                uint8_t x;
                while (!(ns16550_lsr_read(&ns16550) & LSR_DATA_READY));
                
                x = ns16550_rbr_read(&ns16550);
                
                if (x != IGNORE_CODE) {
                        if (x & KEY_RELEASE)
                                key_released(x ^ KEY_RELEASE);
                        else
                                active_read_key_pressed(x);
                }
        }
        return ch;
}

/** Poll for key press and release events.
 *
 * This function can be used to implement keyboard polling.
 */
void ns16550_poll(void)
{
#ifndef CONFIG_NS16550_INTERRUPT_DRIVEN
        ipl_t ipl;

        ipl = interrupts_disable();
        spinlock_lock(&ns16550_irq.lock);

        if (ns16550_lsr_read(&ns16550) & LSR_DATA_READY) {
                if (ns16550_irq.notif_cfg.notify && ns16550_irq.notif_cfg.answerbox) {
                        /*
                         * Send IPC notification.
                         */
                        ipc_irq_send_notif(&ns16550_irq);
                        spinlock_unlock(&ns16550_irq.lock);
                        interrupts_restore(ipl);
                        return;
                }
        }

        spinlock_unlock(&ns16550_irq.lock);
        interrupts_restore(ipl);
#endif

        while (ns16550_lsr_read(&ns16550) & LSR_DATA_READY) {
                uint8_t x;
                
                x = ns16550_rbr_read(&ns16550);
                
                if (x != IGNORE_CODE) {
                        if (x & KEY_RELEASE)
                                key_released(x ^ KEY_RELEASE);
                        else
                                key_pressed(x);
                }
        }
}

irq_ownership_t ns16550_claim(void)
{
        return (ns16550_lsr_read(&ns16550) & LSR_DATA_READY);
}

void ns16550_irq_handler(irq_t *irq, void *arg, ...)
{
        if (irq->notif_cfg.notify && irq->notif_cfg.answerbox)
                ipc_irq_send_notif(irq);
        else
                ns16550_interrupt();
}

/** @}
 */