/*
 *      LASI PS/2 keyboard/psaux driver for HP-PARISC workstations
 *      
 *      (c) Copyright 1999 The Puffin Group Inc.
 *      by Alex deVries <adevries@thepuffingroup.com>
 *      Copyright 1999, 2000 Philipp Rumpf <prumpf@tux.org>
 *
 *      2000/10/26      Debacker Xavier (debackex@esiee.fr)
 *      implemented the psaux and controlled the mouse scancode based on pc_keyb.c
 *                      Marteau Thomas (marteaut@esiee.fr)
 *      fixed leds control
 *
 *      2001/12/17      Marteau Thomas (marteaut@esiee.fr)
 *      get nice initialisation procedure
 */

#include <linux/config.h>

#include <linux/types.h>
#include <linux/ptrace.h>       /* interrupt.h wants struct pt_regs defined */
#include <linux/interrupt.h>
#include <linux/sched.h>        /* for request_irq/free_irq */
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pc_keyb.h>
#include <linux/kbd_kern.h>

/* mouse includes */
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/spinlock.h>
#include <linux/smp_lock.h>
#include <linux/poll.h>

#include <asm/hardware.h>
#include <asm/keyboard.h>
#include <asm/gsc.h>
#include <asm/uaccess.h>

/* HP specific LASI PS/2 keyboard and psaux constants */
#define AUX_REPLY_ACK   0xFA    /* Command byte ACK. */
#define AUX_RESEND      0xFE    /* Sent by the keyb. Asking for resending the last command. */
#define AUX_RECONNECT   0xAA    /* scancode when ps2 device is plugged (back) in */

#define LASI_PSAUX_OFFSET 0x0100 /* offset from keyboard to psaux port */

#define LASI_ID         0x00    /* ID and reset port offsets */
#define LASI_RESET      0x00
#define LASI_RCVDATA    0x04    /* receive and transmit port offsets */
#define LASI_XMTDATA    0x04
#define LASI_CONTROL    0x08    /* see: control register bits */
#define LASI_STATUS     0x0C    /* see: status register bits */

/* control register bits */
#define LASI_CTRL_ENBL  0x01    /* enable interface */
#define LASI_CTRL_LPBXR 0x02    /* loopback operation */
#define LASI_CTRL_DIAG  0x20    /* directly control clock/data line */
#define LASI_CTRL_DATDIR 0x40   /* data line direct control */
#define LASI_CTRL_CLKDIR 0x80   /* clock line direct control */

/* status register bits */
#define LASI_STAT_RBNE  0x01
#define LASI_STAT_TBNE  0x02
#define LASI_STAT_TERR  0x04
#define LASI_STAT_PERR  0x08
#define LASI_STAT_CMPINTR 0x10
#define LASI_STAT_DATSHD 0x40
#define LASI_STAT_CLKSHD 0x80

static spinlock_t       kbd_controller_lock = SPIN_LOCK_UNLOCKED;
static unsigned long lasikbd_hpa;

static volatile int cmd_status;

static inline u8 read_input(unsigned long hpa)
{
        return gsc_readb(hpa+LASI_RCVDATA);
}

static inline u8 read_control(unsigned long hpa)
{
        return gsc_readb(hpa+LASI_CONTROL);
}

static inline void write_control(u8 val, unsigned long hpa)
{
        gsc_writeb(val, hpa+LASI_CONTROL);
}

static inline u8 read_status(unsigned long hpa)
{
        return gsc_readb(hpa+LASI_STATUS);
}

/* XXX should this grab the spinlock? */

static int write_output(u8 val, unsigned long hpa)
{
        int wait = 250;

        while (read_status(hpa) & LASI_STAT_TBNE) {
                if (!--wait) {
                        return 0;
                }
                mdelay(1);
        }
        gsc_writeb(val, hpa+LASI_XMTDATA);

        return 1;
}

/* XXX should this grab the spinlock? */

static u8 wait_input(unsigned long hpa)
{
        int wait = 250;

        while (!(read_status(hpa) & LASI_STAT_RBNE)) {
                if (!--wait) {
                        return 0;
                }
                mdelay(1);
        }
        return read_input(hpa);      
}

/* This function is the PA-RISC adaptation of i386 source */

static inline int aux_write_ack(u8 val)
{
      return write_output(val, lasikbd_hpa+LASI_PSAUX_OFFSET);
}

/* This is wrong, should do something like the pc driver, which sends
 * the command up to 3 times at 1 second intervals, checking once
 * per millisecond for an acknowledge.
 */

static void lasikbd_leds(unsigned char leds)
{
        int loop = 1000;

        if (!lasikbd_hpa)
                return;

        cmd_status=2;
        while (cmd_status!=0 && --loop > 0) {
                write_output(KBD_CMD_SET_LEDS, lasikbd_hpa);
                mdelay(5); 
        }
   
        cmd_status=2;
        while (cmd_status!=0 && --loop > 0) {
                write_output(leds, lasikbd_hpa);
                mdelay(5);
        }

        cmd_status=2;
        while (cmd_status!=0 && --loop > 0) {
           write_output(KBD_CMD_ENABLE, lasikbd_hpa);   
           mdelay(5);
        }
        if (loop <= 0)
                printk("lasikbd_leds: timeout\n");
}

#if 0
/* this might become useful again at some point.  not now  -prumpf */
int lasi_ps2_test(void *hpa)
{
        u8 control,c;
        int i, ret = 0;

        control = read_control(hpa);
        write_control(control | LASI_CTRL_LPBXR | LASI_CTRL_ENBL, hpa);

        for (i=0; i<256; i++) {
                write_output(i, hpa);

                while (!(read_status(hpa) & LASI_STAT_RBNE))
                    /* just wait */;
                    
                c = read_input(hpa);
                if (c != i)
                        ret--;
        }

        write_control(control, hpa);

        return ret;
}
#endif 

static int init_keyb(unsigned long hpa)
{
        int res = 0;
        unsigned long flags;

        spin_lock_irqsave(&kbd_controller_lock, flags);

        if (write_output(KBD_CMD_SET_LEDS, hpa) &&
                        wait_input(hpa) == AUX_REPLY_ACK &&
                        write_output(0, hpa) &&
                        wait_input(hpa) == AUX_REPLY_ACK &&
                        write_output(KBD_CMD_ENABLE, hpa) &&
                        wait_input(hpa) == AUX_REPLY_ACK)
                res = 1;

        spin_unlock_irqrestore(&kbd_controller_lock, flags);

        return res;
}


static void __init lasi_ps2_reset(unsigned long hpa)
{
        u8 control;

        /* reset the interface */
        gsc_writeb(0xff, hpa+LASI_RESET);
        gsc_writeb(0x0 , hpa+LASI_RESET);               

        /* enable it */
        control = read_control(hpa);
        write_control(control | LASI_CTRL_ENBL, hpa);
}

/* Greatly inspired by pc_keyb.c */

/*
 * Wait for keyboard controller input buffer to drain.
 *
 * Don't use 'jiffies' so that we don't depend on
 * interrupts..
 *
 * Quote from PS/2 System Reference Manual:
 *
 * "Address hex 0060 and address hex 0064 should be written only when
 * the input-buffer-full bit and output-buffer-full bit in the
 * Controller Status register are set 0."
 */
#ifdef CONFIG_PSMOUSE

static struct aux_queue *queue;
static unsigned char    mouse_reply_expected;
static int              aux_count;

static int fasync_aux(int fd, struct file *filp, int on)
{
        int retval;
        
        retval = fasync_helper(fd, filp, on, &queue->fasync);
        if (retval < 0)
                return retval;
        
        return 0;
}



static inline void handle_mouse_scancode(unsigned char scancode)
{
        if (mouse_reply_expected) {
                if (scancode == AUX_REPLY_ACK) {
                        mouse_reply_expected--;
                        return;
                }
                mouse_reply_expected = 0;
        }
        else if (scancode == AUX_RECONNECT) {
                queue->head = queue->tail = 0;  /* Flush input queue */
                return;
        }

        add_mouse_randomness(scancode);
        if (aux_count) {
                int head = queue->head;
                                
                queue->buf[head] = scancode;
                head = (head + 1) & (AUX_BUF_SIZE-1);
                
                if (head != queue->tail) {
                        queue->head = head;
                        kill_fasync(&queue->fasync, SIGIO, POLL_IN);
                        wake_up_interruptible(&queue->proc_list);
                }
        }
}

static inline int queue_empty(void)
{
        return queue->head == queue->tail;
}

static unsigned char get_from_queue(void)
{
        unsigned char result;
        unsigned long flags;

        spin_lock_irqsave(&kbd_controller_lock, flags);
        result = queue->buf[queue->tail];
        queue->tail = (queue->tail + 1) & (AUX_BUF_SIZE-1);
        spin_unlock_irqrestore(&kbd_controller_lock, flags);

        return result;
}


/*
 * Write to the aux device.
 */

static ssize_t write_aux(struct file * file, const char * buffer,
                         size_t count, loff_t *ppos)
{
        ssize_t retval = 0;

        if (count) {
                ssize_t written = 0;

                if (count > 32)
                        count = 32; /* Limit to 32 bytes. */
                do {
                        char c;
                        get_user(c, buffer++);
                        written++;
                } while (--count);
                retval = -EIO;
                if (written) {
                        retval = written;
                        file->f_dentry->d_inode->i_mtime = CURRENT_TIME;
                }
        }

        return retval;
}



static ssize_t read_aux(struct file * file, char * buffer,
                        size_t count, loff_t *ppos)
{
        DECLARE_WAITQUEUE(wait, current);
        ssize_t i = count;
        unsigned char c;

        if (queue_empty()) {
                if (file->f_flags & O_NONBLOCK)
                        return -EAGAIN;
                add_wait_queue(&queue->proc_list, &wait);
repeat:
                set_current_state(TASK_INTERRUPTIBLE);
                if (queue_empty() && !signal_pending(current)) {
                        schedule();
                        goto repeat;
                }
                current->state = TASK_RUNNING;
                remove_wait_queue(&queue->proc_list, &wait);
        }
        while (i > 0 && !queue_empty()) {
                c = get_from_queue();
                put_user(c, buffer++);
                i--;
        }
        if (count-i) {
                file->f_dentry->d_inode->i_atime = CURRENT_TIME;
                return count-i;
        }
        if (signal_pending(current))
                return -ERESTARTSYS;
        return 0;
}


static int open_aux(struct inode * inode, struct file * file)
{
        if (aux_count++) 
                return 0;

        queue->head = queue->tail = 0;  /* Flush input queue */
        aux_count = 1;
        aux_write_ack(AUX_ENABLE_DEV);  /* Enable aux device */
        
        return 0;
}


/* No kernel lock held - fine */
static unsigned int aux_poll(struct file *file, poll_table * wait)
{

        poll_wait(file, &queue->proc_list, wait);
        if (!queue_empty())
                return POLLIN | POLLRDNORM;
        return 0;
}


static int release_aux(struct inode * inode, struct file * file)
{
        lock_kernel();
        fasync_aux(-1, file, 0);
        if (--aux_count) {
                unlock_kernel();
                return 0;
        }
        unlock_kernel();
        return 0;
}

static struct file_operations psaux_fops = {
        read:           read_aux,
        write:          write_aux,
        poll:           aux_poll,
        open:           open_aux,
        release:        release_aux,
        fasync:         fasync_aux,
};

static struct miscdevice psaux_mouse = {
        minor:          PSMOUSE_MINOR,
        name:           "psaux",
        fops:           &psaux_fops,
};

#endif /* CONFIG_PSMOUSE */


/* This function is looking at the PS2 controller and empty the two buffers */

static u8 handle_lasikbd_event(unsigned long hpa)
{
        u8 status_keyb,status_mouse,scancode,id;
        extern void handle_at_scancode(int); /* in drivers/char/keyb_at.c */
        
        /* Mask to get the base address of the PS/2 controller */
        id = gsc_readb(hpa+LASI_ID) & 0x0f;
        
        if (id==1) 
                hpa -= LASI_PSAUX_OFFSET; 
        
        status_keyb = read_status(hpa);
        status_mouse = read_status(hpa+LASI_PSAUX_OFFSET);

        while ((status_keyb|status_mouse) & LASI_STAT_RBNE){
           
                while (status_keyb & LASI_STAT_RBNE) {
              
                scancode = read_input(hpa);

                /* XXX don't know if this is a valid fix, but filtering
                 * 0xfa avoids 'unknown scancode' errors on, eg, capslock
                 * on some keyboards.
                 */
                      
                if (scancode == AUX_REPLY_ACK) 
                        cmd_status=0;
                        
                else if (scancode == AUX_RESEND)
                        cmd_status=1;
                else 
                        handle_at_scancode(scancode); 
              
                status_keyb =read_status(hpa);
                }
           
#ifdef CONFIG_PSMOUSE
                while (status_mouse & LASI_STAT_RBNE) {
                        scancode = read_input(hpa+LASI_PSAUX_OFFSET);
                        handle_mouse_scancode(scancode);
                        status_mouse = read_status(hpa+LASI_PSAUX_OFFSET);
                }
                status_mouse = read_status(hpa+LASI_PSAUX_OFFSET);
#endif /* CONFIG_PSMOUSE */
                status_keyb = read_status(hpa);
        }

        tasklet_schedule(&keyboard_tasklet);
        return (status_keyb|status_mouse);
}
        
extern struct pt_regs *kbd_pt_regs;

static void lasikbd_interrupt(int irq, void *dev, struct pt_regs *regs)
{
        kbd_pt_regs = regs;
        handle_lasikbd_event((unsigned long) dev);
}

extern int pckbd_translate(unsigned char, unsigned char *, char);
extern int pckbd_setkeycode(unsigned int, unsigned int);
extern int pckbd_getkeycode(unsigned int);

static struct kbd_ops gsc_ps2_kbd_ops = {
        setkeycode:     pckbd_setkeycode,
        getkeycode:     pckbd_getkeycode,
        translate:      pckbd_translate,
        leds:           lasikbd_leds,
#ifdef CONFIG_MAGIC_SYSRQ
        sysrq_key:      0x54,
        sysrq_xlate:    hp_ps2kbd_sysrq_xlate,
#endif
};



#if 1
/* XXX: HACK !!!
 * remove this function and the call in hil_kbd.c 
 * if hp_psaux.c/hp_keyb.c is converted to the input layer... */
int register_ps2_keybfuncs(void)
{
        gsc_ps2_kbd_ops.leds = NULL;
        register_kbd_ops(&gsc_ps2_kbd_ops);
}
EXPORT_SYMBOL(register_ps2_keybfuncs);
#endif


static int __init
lasi_ps2_register(struct parisc_device *dev)
{
        unsigned long hpa = dev->hpa;
        char *name;
        int device_found = 0;
        u8 id;

        id = gsc_readb(hpa+LASI_ID) & 0x0f;

        switch (id) {
        case 0:
                name = "keyboard";
                lasikbd_hpa = hpa;      /* save "hpa" for lasikbd_leds() */
                break;
        case 1:
                name = "psaux";
                break;
        default:
                printk(KERN_WARNING "%s: Unknown PS/2 port (id=%d) - ignored.\n",
                        __FUNCTION__, id );
                return 0;
        }
        
        /* reset the PS/2 port */
        lasi_ps2_reset(hpa);

        switch (id) {
        case 0: 
                device_found = init_keyb(hpa);
                if (device_found) register_kbd_ops(&gsc_ps2_kbd_ops);
                break;
        case 1:
#ifdef CONFIG_PSMOUSE
                queue = (struct aux_queue *) kmalloc(sizeof(*queue), GFP_KERNEL);
                if (!queue)
                        return -ENOMEM;

                memset(queue, 0, sizeof(*queue));
                queue->head = queue->tail = 0;
                init_waitqueue_head(&queue->proc_list);
                
                misc_register(&psaux_mouse);

                aux_write_ack(AUX_ENABLE_DEV);
                /* try it a second time, this will give status if the device is
                 * available */
                device_found = aux_write_ack(AUX_ENABLE_DEV);
                break;
#else
                /* return without printing any unnecessary and misleading info */
                return 0;       
#endif
        } /* of case */
        
        if (device_found) {
        /* Here we claim only if we have a device attached */   
                /* allocate the irq and memory region for that device */
                if (!dev->irq)
                return -ENODEV;
           
                if (request_irq(dev->irq, lasikbd_interrupt, 0, name, (void *)hpa))
                return -ENODEV;
           
                if (!request_mem_region(hpa, LASI_STATUS + 4, name))
                return -ENODEV;
        }
        
        printk(KERN_INFO "PS/2 %s port at 0x%08lx (irq %d) found, "
                         "%sdevice attached.\n",
                        name, hpa, dev->irq, device_found ? "":"no ");

        return 0;
}

static struct parisc_device_id lasi_psaux_tbl[] = {
        { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 },
        { 0, } /* 0 terminated list */
};

MODULE_DEVICE_TABLE(parisc, lasi_psaux_tbl);

static struct parisc_driver lasi_psaux_driver = {
        name:           "Lasi psaux",
        id_table:       lasi_psaux_tbl,
        probe:          lasi_ps2_register,
};

static int __init gsc_ps2_init(void) 
{
        return register_parisc_driver(&lasi_psaux_driver);
}

module_init(gsc_ps2_init);