// SPDX-License-Identifier: GPL-2.0
/*
 *      linux/arch/alpha/kernel/sys_jensen.c
 *
 *      Copyright (C) 1995 Linus Torvalds
 *      Copyright (C) 1998, 1999 Richard Henderson
 *
 * Code supporting the Jensen.
 */
#define __EXTERN_INLINE
#include <asm/io.h>
#include <asm/jensen.h>
#undef  __EXTERN_INLINE

#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/init.h>

#include <asm/ptrace.h>

#include <asm/dma.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>

#include "proto.h"
#include "irq_impl.h"
#include "pci_impl.h"
#include "machvec_impl.h"


/*
 * Jensen is special: the vector is 0x8X0 for EISA interrupt X, and
 * 0x9X0 for the local motherboard interrupts.
 *
 * Note especially that those local interrupts CANNOT be masked,
 * which causes much of the pain below...
 *
 *      0x660 - NMI
 *
 *      0x800 - IRQ0  interval timer (not used, as we use the RTC timer)
 *      0x810 - IRQ1  line printer (duh..)
 *      0x860 - IRQ6  floppy disk
 *
 *      0x900 - COM1
 *      0x920 - COM2
 *      0x980 - keyboard
 *      0x990 - mouse
 *
 * PCI-based systems are more sane: they don't have the local
 * interrupts at all, and have only normal PCI interrupts from
 * devices.  Happily it's easy enough to do a sane mapping from the
 * Jensen.
 * 
 * Note that this means that we may have to do a hardware
 * "local_op" to a different interrupt than we report to the rest of the
 * world.
 */

static void
jensen_local_enable(struct irq_data *d)
{
        /* the parport is really hw IRQ 1, silly Jensen.  */
        if (d->irq == 7)
                i8259a_enable_irq(d);
}

static void
jensen_local_disable(struct irq_data *d)
{
        /* the parport is really hw IRQ 1, silly Jensen.  */
        if (d->irq == 7)
                i8259a_disable_irq(d);
}

static void
jensen_local_mask_ack(struct irq_data *d)
{
        /* the parport is really hw IRQ 1, silly Jensen.  */
        if (d->irq == 7)
                i8259a_mask_and_ack_irq(d);
}

static struct irq_chip jensen_local_irq_type = {
        .name           = "LOCAL",
        .irq_unmask     = jensen_local_enable,
        .irq_mask       = jensen_local_disable,
        .irq_mask_ack   = jensen_local_mask_ack,
};

static void 
jensen_device_interrupt(unsigned long vector)
{
        int irq;

        switch (vector) {
        case 0x660:
                printk("Whee.. NMI received. Probable hardware error\n");
                printk("61=%02x, 461=%02x\n", inb(0x61), inb(0x461));
                return;

        /* local device interrupts: */
        case 0x900: irq = 4; break;             /* com1 -> irq 4 */
        case 0x920: irq = 3; break;             /* com2 -> irq 3 */
        case 0x980: irq = 1; break;             /* kbd -> irq 1 */
        case 0x990: irq = 9; break;             /* mouse -> irq 9 */

        default:
                if (vector > 0x900) {
                        printk("Unknown local interrupt %lx\n", vector);
                        return;
                }

                irq = (vector - 0x800) >> 4;
                if (irq == 1)
                        irq = 7;
                break;
        }

        /* If there is no handler yet... */
        if (!irq_has_action(irq)) {
            /* If it is a local interrupt that cannot be masked... */
            if (vector >= 0x900)
            {
                /* Clear keyboard/mouse state */
                inb(0x64);
                inb(0x60);
                /* Reset serial ports */
                inb(0x3fa);
                inb(0x2fa);
                outb(0x0c, 0x3fc);
                outb(0x0c, 0x2fc);
                /* Clear NMI */
                outb(0,0x61);
                outb(0,0x461);
            }
        }

#if 0
        /* A useful bit of code to find out if an interrupt is going wild.  */
        {
          static unsigned int last_msg = 0, last_cc = 0;
          static int last_irq = -1, count = 0;
          unsigned int cc;

          __asm __volatile("rpcc %0" : "=r"(cc));
          ++count;
#define JENSEN_CYCLES_PER_SEC   (150000000)
          if (cc - last_msg > ((JENSEN_CYCLES_PER_SEC) * 3) ||
              irq != last_irq) {
                printk(KERN_CRIT " irq %d count %d cc %u @ %lx\n",
                       irq, count, cc-last_cc, get_irq_regs()->pc);
                count = 0;
                last_msg = cc;
                last_irq = irq;
          }
          last_cc = cc;
        }
#endif

        handle_irq(irq);
}

static void __init
jensen_init_irq(void)
{
        init_i8259a_irqs();

        irq_set_chip_and_handler(1, &jensen_local_irq_type, handle_level_irq);
        irq_set_chip_and_handler(4, &jensen_local_irq_type, handle_level_irq);
        irq_set_chip_and_handler(3, &jensen_local_irq_type, handle_level_irq);
        irq_set_chip_and_handler(7, &jensen_local_irq_type, handle_level_irq);
        irq_set_chip_and_handler(9, &jensen_local_irq_type, handle_level_irq);

        common_init_isa_dma();
}

static void __init
jensen_init_arch(void)
{
        struct pci_controller *hose;
#ifdef CONFIG_PCI
        static struct pci_dev fake_isa_bridge = { .dma_mask = 0xffffffffUL, };

        isa_bridge = &fake_isa_bridge;
#endif

        /* Create a hose so that we can report i/o base addresses to
           userland.  */

        pci_isa_hose = hose = alloc_pci_controller();
        hose->io_space = &ioport_resource;
        hose->mem_space = &iomem_resource;
        hose->index = 0;

        hose->sparse_mem_base = EISA_MEM - IDENT_ADDR;
        hose->dense_mem_base = 0;
        hose->sparse_io_base = EISA_IO - IDENT_ADDR;
        hose->dense_io_base = 0;

        hose->sg_isa = hose->sg_pci = NULL;
        __direct_map_base = 0;
        __direct_map_size = 0xffffffff;
}

static void
jensen_machine_check(unsigned long vector, unsigned long la)
{
        printk(KERN_CRIT "Machine check\n");
}

/*
 * The System Vector
 */

struct alpha_machine_vector jensen_mv __initmv = {
        .vector_name            = "Jensen",
        DO_EV4_MMU,
        IO_LITE(JENSEN,jensen),
        .machine_check          = jensen_machine_check,
        .max_isa_dma_address    = ALPHA_MAX_ISA_DMA_ADDRESS,
        .rtc_port               = 0x170,

        .nr_irqs                = 16,
        .device_interrupt       = jensen_device_interrupt,

        .init_arch              = jensen_init_arch,
        .init_irq               = jensen_init_irq,
        .init_rtc               = common_init_rtc,
        .init_pci               = NULL,
        .kill_arch              = NULL,
};
ALIAS_MV(jensen)