source: mainline/kernel/genarch/src/drivers/z8530/z8530.c@ 411b6a6

/*
 * Copyright (c) 2009 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       Zilog 8530 serial controller driver.
 */

#include <genarch/drivers/z8530/z8530.h>
#include <console/chardev.h>
#include <ddi/irq.h>
#include <arch/asm.h>
#include <mm/slab.h>

static inline void z8530_write(ioport8_t *ctl, uint8_t reg, uint8_t val)
{
        /*
         * Registers 8-15 will automatically issue the Point High
         * command as their bit 3 is 1.
         */
        pio_write_8(ctl, reg);  /* select register */
        pio_write_8(ctl, val);  /* write value */
}

static inline uint8_t z8530_read(ioport8_t *ctl, uint8_t reg) 
{
        /*
         * Registers 8-15 will automatically issue the Point High
         * command as their bit 3 is 1.
         */
        pio_write_8(ctl, reg);  /* select register */
        return pio_read_8(ctl);
}

/** Initialize z8530. */
bool
z8530_init(z8530_t *dev, devno_t devno, inr_t inr, cir_t cir, void *cir_arg,
    chardev_t *devout)
{
        z8530_instance_t *instance;

        instance = malloc(sizeof(z8530_instance_t), FRAME_ATOMIC);
        if (!instance)
                return false;

        instance->devno = devno;
        instance->z8530 = dev;
        instance->devout = devout;

        irq_initialize(&instance->irq);
        instance->irq.devno = devno;
        instance->irq.inr = inr;
        instance->irq.claim = z8530_claim;
        instance->irq.handler = z8530_irq_handler;
        instance->irq.instance = instance;
        instance->irq.cir = cir;
        instance->irq.cir_arg = cir_arg;
        irq_register(&instance->irq);

        (void) z8530_read(&dev->ctl_a, RR8);

        /*
         * Clear any pending TX interrupts or we never manage
         * to set FHC UART interrupt state to idle.
         */
        z8530_write(&dev->ctl_a, WR0, WR0_TX_IP_RST);

        /* interrupt on all characters */
        z8530_write(&dev->ctl_a, WR1, WR1_IARCSC);

        /* 8 bits per character and enable receiver */
        z8530_write(&dev->ctl_a, WR3, WR3_RX8BITSCH | WR3_RX_ENABLE);
        
        /* Master Interrupt Enable. */
        z8530_write(&dev->ctl_a, WR9, WR9_MIE);

        return true;
}

irq_ownership_t z8530_claim(irq_t *irq)
{
        z8530_instance_t *instance = irq->instance;
        z8530_t *dev = instance->z8530;

        if (z8530_read(&dev->ctl_a, RR0) & RR0_RCA)
                return IRQ_ACCEPT;
        else
                return IRQ_DECLINE;
}

void z8530_irq_handler(irq_t *irq)
{
        z8530_instance_t *instance = irq->instance;
        z8530_t *dev = instance->z8530;
        uint8_t x;

        if (z8530_read(&dev->ctl_a, RR0) & RR0_RCA) {
                x = z8530_read(&dev->ctl_a, RR8);
                if (instance->devout)
                        chardev_push_character(instance->devout, x);
        }
}

/** @}
 */