// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/hil/hilkbd.c
 *
 *  Copyright (C) 1998 Philip Blundell <philb@gnu.org>
 *  Copyright (C) 1999 Matthew Wilcox <willy@infradead.org>
 *  Copyright (C) 1999-2007 Helge Deller <deller@gmx.de>
 *
 *  Very basic HP Human Interface Loop (HIL) driver.
 *  This driver handles the keyboard on HP300 (m68k) and on some
 *  HP700 (parisc) series machines.
 */

#include <linux/pci_ids.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/hil.h>
#include <linux/io.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <asm/irq.h>
#ifdef CONFIG_HP300
#include <asm/hwtest.h>
#endif


MODULE_AUTHOR("Philip Blundell, Matthew Wilcox, Helge Deller");
MODULE_DESCRIPTION("HIL keyboard driver (basic functionality)");
MODULE_LICENSE("GPL v2");


#if defined(CONFIG_PARISC)

 #include <asm/io.h>
 #include <asm/hardware.h>
 #include <asm/parisc-device.h>
 static unsigned long hil_base; /* HPA for the HIL device */
 static unsigned int hil_irq;
 #define HILBASE                hil_base /* HPPA (parisc) port address */
 #define HIL_DATA               0x800
 #define HIL_CMD                0x801
 #define HIL_IRQ                hil_irq
 #define hil_readb(p)           gsc_readb(p)
 #define hil_writeb(v,p)        gsc_writeb((v),(p))

#elif defined(CONFIG_HP300)

 #define HILBASE                0xf0428000UL /* HP300 (m68k) port address */
 #define HIL_DATA               0x1
 #define HIL_CMD                0x3
 #define HIL_IRQ                2
 #define hil_readb(p)           readb((const volatile void __iomem *)(p))
 #define hil_writeb(v, p)       writeb((v), (volatile void __iomem *)(p))

#else
#error "HIL is not supported on this platform"
#endif



/* HIL helper functions */

#define hil_busy()              (hil_readb(HILBASE + HIL_CMD) & HIL_BUSY)
#define hil_data_available()    (hil_readb(HILBASE + HIL_CMD) & HIL_DATA_RDY)
#define hil_status()            (hil_readb(HILBASE + HIL_CMD))
#define hil_command(x)          do { hil_writeb((x), HILBASE + HIL_CMD); } while (0)
#define hil_read_data()         (hil_readb(HILBASE + HIL_DATA))
#define hil_write_data(x)       do { hil_writeb((x), HILBASE + HIL_DATA); } while (0)

/* HIL constants */

#define HIL_BUSY                0x02
#define HIL_DATA_RDY            0x01

#define HIL_SETARD              0xA0            /* set auto-repeat delay */
#define HIL_SETARR              0xA2            /* set auto-repeat rate */
#define HIL_SETTONE             0xA3            /* set tone generator */
#define HIL_CNMT                0xB2            /* clear nmi */
#define HIL_INTON               0x5C            /* Turn on interrupts. */
#define HIL_INTOFF              0x5D            /* Turn off interrupts. */

#define HIL_READKBDSADR         0xF9
#define HIL_WRITEKBDSADR        0xE9

static unsigned int hphilkeyb_keycode[HIL_KEYCODES_SET1_TBLSIZE] __read_mostly =
        { HIL_KEYCODES_SET1 };

/* HIL structure */
static struct {
        struct input_dev *dev;

        unsigned int curdev;

        unsigned char s;
        unsigned char c;
        int valid;

        unsigned char data[16];
        unsigned int ptr;
        spinlock_t lock;

        void *dev_id;   /* native bus device */
} hil_dev;


static void poll_finished(void)
{
        int down;
        int key;
        unsigned char scode;

        switch (hil_dev.data[0]) {
        case 0x40:
                down = (hil_dev.data[1] & 1) == 0;
                scode = hil_dev.data[1] >> 1;
                key = hphilkeyb_keycode[scode];
                input_report_key(hil_dev.dev, key, down);
                break;
        }
        hil_dev.curdev = 0;
}


static inline void handle_status(unsigned char s, unsigned char c)
{
        if (c & 0x8) {
                /* End of block */
                if (c & 0x10)
                        poll_finished();
        } else {
                if (c & 0x10) {
                        if (hil_dev.curdev)
                                poll_finished();  /* just in case */
                        hil_dev.curdev = c & 7;
                        hil_dev.ptr = 0;
                }
        }
}


static inline void handle_data(unsigned char s, unsigned char c)
{
        if (hil_dev.curdev) {
                hil_dev.data[hil_dev.ptr++] = c;
                hil_dev.ptr &= 15;
        }
}


/* handle HIL interrupts */
static irqreturn_t hil_interrupt(int irq, void *handle)
{
        unsigned char s, c;

        s = hil_status();
        c = hil_read_data();

        switch (s >> 4) {
        case 0x5:
                handle_status(s, c);
                break;
        case 0x6:
                handle_data(s, c);
                break;
        case 0x4:
                hil_dev.s = s;
                hil_dev.c = c;
                mb();
                hil_dev.valid = 1;
                break;
        }
        return IRQ_HANDLED;
}


/* send a command to the HIL */
static void hil_do(unsigned char cmd, unsigned char *data, unsigned int len)
{
        guard(spinlock_irqsave)(&hil_dev.lock);

        while (hil_busy())
                /* wait */;
        hil_command(cmd);
        while (len--) {
                while (hil_busy())
                        /* wait */;
                hil_write_data(*(data++));
        }
}


/* initialize HIL */
static int hil_keyb_init(void)
{
        unsigned char c;
        unsigned int i, kbid;
        wait_queue_head_t hil_wait;
        int err;

        if (hil_dev.dev)
                return -ENODEV; /* already initialized */

        init_waitqueue_head(&hil_wait);
        spin_lock_init(&hil_dev.lock);

        hil_dev.dev = input_allocate_device();
        if (!hil_dev.dev)
                return -ENOMEM;

        err = request_irq(HIL_IRQ, hil_interrupt, 0, "hil", hil_dev.dev_id);
        if (err) {
                printk(KERN_ERR "HIL: Can't get IRQ\n");
                goto err1;
        }

        /* Turn on interrupts */
        hil_do(HIL_INTON, NULL, 0);

        /* Look for keyboards */
        hil_dev.valid = 0;      /* clear any pending data */
        hil_do(HIL_READKBDSADR, NULL, 0);

        wait_event_interruptible_timeout(hil_wait, hil_dev.valid, 3 * HZ);
        if (!hil_dev.valid)
                printk(KERN_WARNING "HIL: timed out, assuming no keyboard present\n");

        c = hil_dev.c;
        hil_dev.valid = 0;
        if (c == 0) {
                kbid = -1;
                printk(KERN_WARNING "HIL: no keyboard present\n");
        } else {
                kbid = ffz(~c);
                printk(KERN_INFO "HIL: keyboard found at id %d\n", kbid);
        }

        /* set it to raw mode */
        c = 0;
        hil_do(HIL_WRITEKBDSADR, &c, 1);

        for (i = 0; i < HIL_KEYCODES_SET1_TBLSIZE; i++)
                if (hphilkeyb_keycode[i] != KEY_RESERVED)
                        __set_bit(hphilkeyb_keycode[i], hil_dev.dev->keybit);

        hil_dev.dev->evbit[0]   = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
        hil_dev.dev->ledbit[0]  = BIT_MASK(LED_NUML) | BIT_MASK(LED_CAPSL) |
                BIT_MASK(LED_SCROLLL);
        hil_dev.dev->keycodemax = HIL_KEYCODES_SET1_TBLSIZE;
        hil_dev.dev->keycodesize= sizeof(hphilkeyb_keycode[0]);
        hil_dev.dev->keycode    = hphilkeyb_keycode;
        hil_dev.dev->name       = "HIL keyboard";
        hil_dev.dev->phys       = "hpkbd/input0";

        hil_dev.dev->id.bustype = BUS_HIL;
        hil_dev.dev->id.vendor  = PCI_VENDOR_ID_HP;
        hil_dev.dev->id.product = 0x0001;
        hil_dev.dev->id.version = 0x0010;

        err = input_register_device(hil_dev.dev);
        if (err) {
                printk(KERN_ERR "HIL: Can't register device\n");
                goto err2;
        }

        printk(KERN_INFO "input: %s, ID %d at 0x%08lx (irq %d) found and attached\n",
               hil_dev.dev->name, kbid, HILBASE, HIL_IRQ);

        return 0;

err2:
        hil_do(HIL_INTOFF, NULL, 0);
        free_irq(HIL_IRQ, hil_dev.dev_id);
err1:
        input_free_device(hil_dev.dev);
        hil_dev.dev = NULL;
        return err;
}

static void hil_keyb_exit(void)
{
        if (HIL_IRQ)
                free_irq(HIL_IRQ, hil_dev.dev_id);

        /* Turn off interrupts */
        hil_do(HIL_INTOFF, NULL, 0);

        input_unregister_device(hil_dev.dev);
        hil_dev.dev = NULL;
}

#if defined(CONFIG_PARISC)
static int __init hil_probe_chip(struct parisc_device *dev)
{
        /* Only allow one HIL keyboard */
        if (hil_dev.dev)
                return -ENODEV;

        if (!dev->irq) {
                printk(KERN_WARNING "HIL: IRQ not found for HIL bus at 0x%p\n",
                        (void *)dev->hpa.start);
                return -ENODEV;
        }

        hil_base = dev->hpa.start;
        hil_irq  = dev->irq;
        hil_dev.dev_id = dev;

        printk(KERN_INFO "Found HIL bus at 0x%08lx, IRQ %d\n", hil_base, hil_irq);

        return hil_keyb_init();
}

static void __exit hil_remove_chip(struct parisc_device *dev)
{
        hil_keyb_exit();
}

static const struct parisc_device_id hil_tbl[] __initconst = {
        { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00073 },
        { 0, }
};

#if 0
/* Disabled to avoid conflicts with the HP SDC HIL drivers */
MODULE_DEVICE_TABLE(parisc, hil_tbl);
#endif

static struct parisc_driver hil_driver __refdata = {
        .name           = "hil",
        .id_table       = hil_tbl,
        .probe          = hil_probe_chip,
        .remove         = __exit_p(hil_remove_chip),
};

static int __init hil_init(void)
{
        return register_parisc_driver(&hil_driver);
}

static void __exit hil_exit(void)
{
        unregister_parisc_driver(&hil_driver);
}

#else /* !CONFIG_PARISC */

static int __init hil_init(void)
{
        int error;

        /* Only allow one HIL keyboard */
        if (hil_dev.dev)
                return -EBUSY;

        if (!MACH_IS_HP300)
                return -ENODEV;

        if (!hwreg_present((void *)(HILBASE + HIL_DATA))) {
                printk(KERN_ERR "HIL: hardware register was not found\n");
                return -ENODEV;
        }

        if (!request_region(HILBASE + HIL_DATA, 2, "hil")) {
                printk(KERN_ERR "HIL: IOPORT region already used\n");
                return -EIO;
        }

        error = hil_keyb_init();
        if (error) {
                release_region(HILBASE + HIL_DATA, 2);
                return error;
        }

        return 0;
}

static void __exit hil_exit(void)
{
        hil_keyb_exit();
        release_region(HILBASE + HIL_DATA, 2);
}

#endif /* CONFIG_PARISC */

module_init(hil_init);
module_exit(hil_exit);