picvue.c

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/*
 * Picvue PVC160206 display driver
 *
 * Brian Murphy <[email protected]>
 *
 */
#include <linux/kernel.h>
#include <linux/delay.h>
#include <asm/bootinfo.h>
#include <asm/lasat/lasat.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/string.h>

#include "picvue.h"

#define PVC_BUSY        0x80
#define PVC_NLINES      2
#define PVC_DISPMEM     80
#define PVC_LINELEN     PVC_DISPMEM / PVC_NLINES

struct pvc_defs *picvue;

static void pvc_reg_write(u32 val)
{
    *picvue->reg = val;
}

static u32 pvc_reg_read(void)
{
    u32 tmp = *picvue->reg;
    return tmp;
}

static void pvc_write_byte(u32 data, u8 byte)
{
    data |= picvue->e;
    pvc_reg_write(data);
    data &= ~picvue->data_mask;
    data |= byte << picvue->data_shift;
    pvc_reg_write(data);
    ndelay(220);
    pvc_reg_write(data & ~picvue->e);
    ndelay(220);
}

static u8 pvc_read_byte(u32 data)
{
    u8 byte;

    data |= picvue->e;
    pvc_reg_write(data);
    ndelay(220);
    byte = (pvc_reg_read() & picvue->data_mask) >> picvue->data_shift;
    data &= ~picvue->e;
    pvc_reg_write(data);
    ndelay(220);
    return byte;
}

static u8 pvc_read_data(void)
{
    u32 data = pvc_reg_read();
    u8 byte;
    data |= picvue->rw;
    data &= ~picvue->rs;
    pvc_reg_write(data);
    ndelay(40);
    byte = pvc_read_byte(data);
    data |= picvue->rs;
    pvc_reg_write(data);
    return byte;
}

#define TIMEOUT 1000
static int pvc_wait(void)
{
    int i = TIMEOUT;
    int err = 0;

    while ((pvc_read_data() & PVC_BUSY) && i)
        i--;
    if (i == 0)
        err = -ETIME;

    return err;
}

#define MODE_INST 0
#define MODE_DATA 1
static void pvc_write(u8 byte, int mode)
{
    u32 data = pvc_reg_read();
    data &= ~picvue->rw;
    if (mode == MODE_DATA)
        data |= picvue->rs;
    else
        data &= ~picvue->rs;
    pvc_reg_write(data);
    ndelay(40);
    pvc_write_byte(data, byte);
    if (mode == MODE_DATA)
        data &= ~picvue->rs;
    else
        data |= picvue->rs;
    pvc_reg_write(data);
    pvc_wait();
}

void pvc_write_string(const unsigned char *str, u8 addr, int line)
{
    int i = 0;

    if (line > 0 && (PVC_NLINES > 1))
        addr += 0x40 * line;
    pvc_write(0x80 | addr, MODE_INST);

    while (*str != 0 && i < PVC_LINELEN) {
        pvc_write(*str++, MODE_DATA);
        i++;
    }
}

void pvc_write_string_centered(const unsigned char *str, int line)
{
    int len = strlen(str);
    u8 addr;

    if (len > PVC_VISIBLE_CHARS)
        addr = 0;
    else
        addr = (PVC_VISIBLE_CHARS - strlen(str))/2;

    pvc_write_string(str, addr, line);
}

void pvc_dump_string(const unsigned char *str)
{
    int len = strlen(str);

    pvc_write_string(str, 0, 0);
    if (len > PVC_VISIBLE_CHARS)
        pvc_write_string(&str[PVC_VISIBLE_CHARS], 0, 1);
}

#define BM_SIZE         8
#define MAX_PROGRAMMABLE_CHARS  8
int pvc_program_cg(int charnum, u8 bitmap[BM_SIZE])
{
    int i;
    int addr;

    if (charnum > MAX_PROGRAMMABLE_CHARS)
        return -ENOENT;

    addr = charnum * 8;
    pvc_write(0x40 | addr, MODE_INST);

    for (i = 0; i < BM_SIZE; i++)
        pvc_write(bitmap[i], MODE_DATA);
    return 0;
}

#define FUNC_SET_CMD    0x20
#define  EIGHT_BYTE (1 << 4)
#define  FOUR_BYTE  0
#define  TWO_LINES  (1 << 3)
#define  ONE_LINE   0
#define  LARGE_FONT (1 << 2)
#define  SMALL_FONT 0

static void pvc_funcset(u8 cmd)
{
    pvc_write(FUNC_SET_CMD | (cmd & (EIGHT_BYTE|TWO_LINES|LARGE_FONT)),
          MODE_INST);
}

#define ENTRYMODE_CMD       0x4
#define  AUTO_INC       (1 << 1)
#define  AUTO_DEC       0
#define  CURSOR_FOLLOWS_DISP    (1 << 0)

static void pvc_entrymode(u8 cmd)
{
    pvc_write(ENTRYMODE_CMD | (cmd & (AUTO_INC|CURSOR_FOLLOWS_DISP)),
          MODE_INST);
}

#define DISP_CNT_CMD    0x08
#define  DISP_OFF   0
#define  DISP_ON    (1 << 2)
#define  CUR_ON     (1 << 1)
#define  CUR_BLINK  (1 << 0)
void pvc_dispcnt(u8 cmd)
{
    pvc_write(DISP_CNT_CMD | (cmd & (DISP_ON|CUR_ON|CUR_BLINK)), MODE_INST);
}

#define MOVE_CMD    0x10
#define  DISPLAY    (1 << 3)
#define  CURSOR     0
#define  RIGHT      (1 << 2)
#define  LEFT       0
void pvc_move(u8 cmd)
{
    pvc_write(MOVE_CMD | (cmd & (DISPLAY|RIGHT)), MODE_INST);
}

#define CLEAR_CMD   0x1
void pvc_clear(void)
{
    pvc_write(CLEAR_CMD, MODE_INST);
}

#define HOME_CMD    0x2
void pvc_home(void)
{
    pvc_write(HOME_CMD, MODE_INST);
}

int pvc_init(void)
{
    u8 cmd = EIGHT_BYTE;

    if (PVC_NLINES == 2)
        cmd |= (SMALL_FONT|TWO_LINES);
    else
        cmd |= (LARGE_FONT|ONE_LINE);
    pvc_funcset(cmd);
    pvc_dispcnt(DISP_ON);
    pvc_entrymode(AUTO_INC);

    pvc_clear();
    pvc_write_string_centered("Display", 0);
    pvc_write_string_centered("Initialized", 1);

    return 0;
}

module_init(pvc_init);
MODULE_LICENSE("GPL");