source: mainline/kernel/genarch/src/drivers/z8530/z8530.c@ f1fc83a

/*
 * 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>
#include <ddi/device.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);
}

static 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;
}

static void z8530_irq_handler(irq_t *irq)
{
        z8530_instance_t *instance = irq->instance;
        z8530_t *dev = instance->z8530;
        
        if (z8530_read(&dev->ctl_a, RR0) & RR0_RCA) {
                uint8_t data = z8530_read(&dev->ctl_a, RR8);
                indev_push_character(instance->kbrdin, data);
        }
}

/** Initialize z8530. */
z8530_instance_t *z8530_init(z8530_t *dev, inr_t inr, cir_t cir, void *cir_arg)
{
        z8530_instance_t *instance
            = malloc(sizeof(z8530_instance_t), FRAME_ATOMIC);
        if (instance) {
                instance->z8530 = dev;
                instance->kbrdin = NULL;
                
                irq_initialize(&instance->irq);
                instance->irq.devno = device_assign_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;
        }
        
        return instance;
}

void z8530_wire(z8530_instance_t *instance, indev_t *kbrdin)
{
        ASSERT(instance);
        ASSERT(kbrdin);
        
        instance->kbrdin = kbrdin;
        
        irq_register(&instance->irq);
        
        (void) z8530_read(&instance->z8530->ctl_a, RR8);
        
        /*
         * Clear any pending TX interrupts or we never manage
         * to set FHC UART interrupt state to idle.
         */
        z8530_write(&instance->z8530->ctl_a, WR0, WR0_TX_IP_RST);
        
        /* interrupt on all characters */
        z8530_write(&instance->z8530->ctl_a, WR1, WR1_IARCSC);
        
        /* 8 bits per character and enable receiver */
        z8530_write(&instance->z8530->ctl_a, WR3, WR3_RX8BITSCH | WR3_RX_ENABLE);
        
        /* Master Interrupt Enable. */
        z8530_write(&instance->z8530->ctl_a, WR9, WR9_MIE);
}

/** @}
 */