broadsheetfb.c

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/*
 * broadsheetfb.c -- FB driver for E-Ink Broadsheet controller
 *
 * Copyright (C) 2008, Jaya Kumar
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file COPYING in the main directory of this archive for
 * more details.
 *
 * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
 *
 * This driver is written to be used with the Broadsheet display controller.
 *
 * It is intended to be architecture independent. A board specific driver
 * must be used to perform all the physical IO interactions.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/list.h>
#include <linux/firmware.h>
#include <linux/uaccess.h>

#include <video/broadsheetfb.h>

/* track panel specific parameters */
struct panel_info {
    int w;
    int h;
    u16 sdcfg;
    u16 gdcfg;
    u16 lutfmt;
    u16 fsynclen;
    u16 fendfbegin;
    u16 lsynclen;
    u16 lendlbegin;
    u16 pixclk;
};

/* table of panel specific parameters to be indexed into by the board drivers */
static struct panel_info panel_table[] = {
    {   /* standard 6" on TFT backplane */
        .w = 800,
        .h = 600,
        .sdcfg = (100 | (1 << 8) | (1 << 9)),
        .gdcfg = 2,
        .lutfmt = (4 | (1 << 7)),
        .fsynclen = 4,
        .fendfbegin = (10 << 8) | 4,
        .lsynclen = 10,
        .lendlbegin = (100 << 8) | 4,
        .pixclk = 6,
    },
    {   /* custom 3.7" flexible on PET or steel */
        .w = 320,
        .h = 240,
        .sdcfg = (67 | (0 << 8) | (0 << 9) | (0 << 10) | (0 << 12)),
        .gdcfg = 3,
        .lutfmt = (4 | (1 << 7)),
        .fsynclen = 0,
        .fendfbegin = (80 << 8) | 4,
        .lsynclen = 10,
        .lendlbegin = (80 << 8) | 20,
        .pixclk = 14,
    },
    {   /* standard 9.7" on TFT backplane */
        .w = 1200,
        .h = 825,
        .sdcfg = (100 | (1 << 8) | (1 << 9) | (0 << 10) | (0 << 12)),
        .gdcfg = 2,
        .lutfmt = (4 | (1 << 7)),
        .fsynclen = 0,
        .fendfbegin = (4 << 8) | 4,
        .lsynclen = 4,
        .lendlbegin = (60 << 8) | 10,
        .pixclk = 3,
    },
};

#define DPY_W 800
#define DPY_H 600

static struct fb_fix_screeninfo broadsheetfb_fix __devinitdata = {
    .id =       "broadsheetfb",
    .type =     FB_TYPE_PACKED_PIXELS,
    .visual =   FB_VISUAL_STATIC_PSEUDOCOLOR,
    .xpanstep = 0,
    .ypanstep = 0,
    .ywrapstep =    0,
    .line_length =  DPY_W,
    .accel =    FB_ACCEL_NONE,
};

static struct fb_var_screeninfo broadsheetfb_var __devinitdata = {
    .xres       = DPY_W,
    .yres       = DPY_H,
    .xres_virtual   = DPY_W,
    .yres_virtual   = DPY_H,
    .bits_per_pixel = 8,
    .grayscale  = 1,
    .red =      { 0, 4, 0 },
    .green =    { 0, 4, 0 },
    .blue =     { 0, 4, 0 },
    .transp =   { 0, 0, 0 },
};

/* main broadsheetfb functions */
static void broadsheet_gpio_issue_data(struct broadsheetfb_par *par, u16 data)
{
    par->board->set_ctl(par, BS_WR, 0);
    par->board->set_hdb(par, data);
    par->board->set_ctl(par, BS_WR, 1);
}

static void broadsheet_gpio_issue_cmd(struct broadsheetfb_par *par, u16 data)
{
    par->board->set_ctl(par, BS_DC, 0);
    broadsheet_gpio_issue_data(par, data);
}

static void broadsheet_gpio_send_command(struct broadsheetfb_par *par, u16 data)
{
    par->board->wait_for_rdy(par);

    par->board->set_ctl(par, BS_CS, 0);
    broadsheet_gpio_issue_cmd(par, data);
    par->board->set_ctl(par, BS_DC, 1);
    par->board->set_ctl(par, BS_CS, 1);
}

static void broadsheet_gpio_send_cmdargs(struct broadsheetfb_par *par, u16 cmd,
                    int argc, u16 *argv)
{
    int i;

    par->board->wait_for_rdy(par);

    par->board->set_ctl(par, BS_CS, 0);
    broadsheet_gpio_issue_cmd(par, cmd);
    par->board->set_ctl(par, BS_DC, 1);

    for (i = 0; i < argc; i++)
        broadsheet_gpio_issue_data(par, argv[i]);
    par->board->set_ctl(par, BS_CS, 1);
}

static void broadsheet_mmio_send_cmdargs(struct broadsheetfb_par *par, u16 cmd,
                    int argc, u16 *argv)
{
    int i;

    par->board->mmio_write(par, BS_MMIO_CMD, cmd);

    for (i = 0; i < argc; i++)
        par->board->mmio_write(par, BS_MMIO_DATA, argv[i]);
}

static void broadsheet_send_command(struct broadsheetfb_par *par, u16 data)
{
    if (par->board->mmio_write)
        par->board->mmio_write(par, BS_MMIO_CMD, data);
    else
        broadsheet_gpio_send_command(par, data);
}

static void broadsheet_send_cmdargs(struct broadsheetfb_par *par, u16 cmd,
                    int argc, u16 *argv)
{
    if (par->board->mmio_write)
        broadsheet_mmio_send_cmdargs(par, cmd, argc, argv);
    else
        broadsheet_gpio_send_cmdargs(par, cmd, argc, argv);
}

static void broadsheet_gpio_burst_write(struct broadsheetfb_par *par, int size,
                    u16 *data)
{
    int i;
    u16 tmp;

    par->board->set_ctl(par, BS_CS, 0);
    par->board->set_ctl(par, BS_DC, 1);

    for (i = 0; i < size; i++) {
        par->board->set_ctl(par, BS_WR, 0);
        tmp = (data[i] & 0x0F) << 4;
        tmp |= (data[i] & 0x0F00) << 4;
        par->board->set_hdb(par, tmp);
        par->board->set_ctl(par, BS_WR, 1);
    }

    par->board->set_ctl(par, BS_CS, 1);
}

static void broadsheet_mmio_burst_write(struct broadsheetfb_par *par, int size,
                   u16 *data)
{
    int i;
    u16 tmp;

    for (i = 0; i < size; i++) {
        tmp = (data[i] & 0x0F) << 4;
        tmp |= (data[i] & 0x0F00) << 4;
        par->board->mmio_write(par, BS_MMIO_DATA, tmp);
    }

}

static void broadsheet_burst_write(struct broadsheetfb_par *par, int size,
                   u16 *data)
{
    if (par->board->mmio_write)
        broadsheet_mmio_burst_write(par, size, data);
    else
        broadsheet_gpio_burst_write(par, size, data);
}

static u16 broadsheet_gpio_get_data(struct broadsheetfb_par *par)
{
    u16 res;
    /* wait for ready to go hi. (lo is busy) */
    par->board->wait_for_rdy(par);

    /* cs lo, dc lo for cmd, we lo for each data, db as usual */
    par->board->set_ctl(par, BS_DC, 1);
    par->board->set_ctl(par, BS_CS, 0);
    par->board->set_ctl(par, BS_WR, 0);

    res = par->board->get_hdb(par);

    /* strobe wr */
    par->board->set_ctl(par, BS_WR, 1);
    par->board->set_ctl(par, BS_CS, 1);

    return res;
}


static u16 broadsheet_get_data(struct broadsheetfb_par *par)
{
    if (par->board->mmio_read)
        return par->board->mmio_read(par);
    else
        return broadsheet_gpio_get_data(par);
}

static void broadsheet_gpio_write_reg(struct broadsheetfb_par *par, u16 reg,
                    u16 data)
{
    /* wait for ready to go hi. (lo is busy) */
    par->board->wait_for_rdy(par);

    /* cs lo, dc lo for cmd, we lo for each data, db as usual */
    par->board->set_ctl(par, BS_CS, 0);

    broadsheet_gpio_issue_cmd(par, BS_CMD_WR_REG);

    par->board->set_ctl(par, BS_DC, 1);

    broadsheet_gpio_issue_data(par, reg);
    broadsheet_gpio_issue_data(par, data);

    par->board->set_ctl(par, BS_CS, 1);
}

static void broadsheet_mmio_write_reg(struct broadsheetfb_par *par, u16 reg,
                 u16 data)
{
    par->board->mmio_write(par, BS_MMIO_CMD, BS_CMD_WR_REG);
    par->board->mmio_write(par, BS_MMIO_DATA, reg);
    par->board->mmio_write(par, BS_MMIO_DATA, data);

}

static void broadsheet_write_reg(struct broadsheetfb_par *par, u16 reg,
                    u16 data)
{
    if (par->board->mmio_write)
        broadsheet_mmio_write_reg(par, reg, data);
    else
        broadsheet_gpio_write_reg(par, reg, data);
}

static void broadsheet_write_reg32(struct broadsheetfb_par *par, u16 reg,
                    u32 data)
{
    broadsheet_write_reg(par, reg, cpu_to_le32(data) & 0xFFFF);
    broadsheet_write_reg(par, reg + 2, (cpu_to_le32(data) >> 16) & 0xFFFF);
}


static u16 broadsheet_read_reg(struct broadsheetfb_par *par, u16 reg)
{
    broadsheet_send_cmdargs(par, BS_CMD_RD_REG, 1, &reg);
    par->board->wait_for_rdy(par);
    return broadsheet_get_data(par);
}

/* functions for waveform manipulation */
static int is_broadsheet_pll_locked(struct broadsheetfb_par *par)
{
    return broadsheet_read_reg(par, 0x000A) & 0x0001;
}

static int broadsheet_setup_plls(struct broadsheetfb_par *par)
{
    int retry_count = 0;
    u16 tmp;

    /* disable arral saemipu mode */
    broadsheet_write_reg(par, 0x0006, 0x0000);

    broadsheet_write_reg(par, 0x0010, 0x0004);
    broadsheet_write_reg(par, 0x0012, 0x5949);
    broadsheet_write_reg(par, 0x0014, 0x0040);
    broadsheet_write_reg(par, 0x0016, 0x0000);

    do {
        if (retry_count++ > 100)
            return -ETIMEDOUT;
        mdelay(1);
    } while (!is_broadsheet_pll_locked(par));

    tmp = broadsheet_read_reg(par, 0x0006);
    tmp &= ~0x1;
    broadsheet_write_reg(par, 0x0006, tmp);

    return 0;
}

static int broadsheet_setup_spi(struct broadsheetfb_par *par)
{

    broadsheet_write_reg(par, 0x0204, ((3 << 3) | 1));
    broadsheet_write_reg(par, 0x0208, 0x0001);

    return 0;
}

static int broadsheet_setup_spiflash(struct broadsheetfb_par *par,
                        u16 *orig_sfmcd)
{

    *orig_sfmcd = broadsheet_read_reg(par, 0x0204);
    broadsheet_write_reg(par, 0x0208, 0);
    broadsheet_write_reg(par, 0x0204, 0);
    broadsheet_write_reg(par, 0x0204, ((3 << 3) | 1));

    return 0;
}

static int broadsheet_spiflash_wait_for_bit(struct broadsheetfb_par *par,
                        u16 reg, int bitnum, int val,
                        int timeout)
{
    u16 tmp;

    do {
        tmp = broadsheet_read_reg(par, reg);
        if (((tmp >> bitnum) & 1) == val)
            return 0;
        mdelay(1);
    } while (timeout--);

    return -ETIMEDOUT;
}

static int broadsheet_spiflash_write_byte(struct broadsheetfb_par *par, u8 data)
{
    broadsheet_write_reg(par, 0x0202, (data | 0x100));

    return broadsheet_spiflash_wait_for_bit(par, 0x0206, 3, 0, 100);
}

static int broadsheet_spiflash_read_byte(struct broadsheetfb_par *par, u8 *data)
{
    int err;
    u16 tmp;

    broadsheet_write_reg(par, 0x0202, 0);

    err = broadsheet_spiflash_wait_for_bit(par, 0x0206, 3, 0, 100);
    if (err)
        return err;

    tmp = broadsheet_read_reg(par, 0x200);

    *data = tmp & 0xFF;

    return 0;
}

static int broadsheet_spiflash_wait_for_status(struct broadsheetfb_par *par,
                                int timeout)
{
    u8 tmp;
    int err;

    do {
        broadsheet_write_reg(par, 0x0208, 1);

        err = broadsheet_spiflash_write_byte(par, 0x05);
        if (err)
            goto failout;

        err = broadsheet_spiflash_read_byte(par, &tmp);
        if (err)
            goto failout;

        broadsheet_write_reg(par, 0x0208, 0);

        if (!(tmp & 0x1))
            return 0;

        mdelay(5);
    } while (timeout--);

    dev_err(par->info->device, "Timed out waiting for spiflash status\n");
    return -ETIMEDOUT;

failout:
    broadsheet_write_reg(par, 0x0208, 0);
    return err;
}

static int broadsheet_spiflash_op_on_address(struct broadsheetfb_par *par,
                            u8 op, u32 addr)
{
    int i;
    u8 tmp;
    int err;

    broadsheet_write_reg(par, 0x0208, 1);

    err = broadsheet_spiflash_write_byte(par, op);
    if (err)
        return err;

    for (i = 2; i >= 0; i--) {
        tmp = ((addr >> (i * 8)) & 0xFF);
        err = broadsheet_spiflash_write_byte(par, tmp);
        if (err)
            return err;
    }

    return err;
}

static int broadsheet_verify_spiflash(struct broadsheetfb_par *par,
                        int *flash_type)
{
    int err = 0;
    u8 sig;

    err = broadsheet_spiflash_op_on_address(par, 0xAB, 0x00000000);
    if (err)
        goto failout;

    err = broadsheet_spiflash_read_byte(par, &sig);
    if (err)
        goto failout;

    if ((sig != 0x10) && (sig != 0x11)) {
        dev_err(par->info->device, "Unexpected flash type\n");
        err = -EINVAL;
        goto failout;
    }

    *flash_type = sig;

failout:
    broadsheet_write_reg(par, 0x0208, 0);
    return err;
}

static int broadsheet_setup_for_wfm_write(struct broadsheetfb_par *par,
                    u16 *initial_sfmcd, int *flash_type)

{
    int err;

    err = broadsheet_setup_plls(par);
    if (err)
        return err;

    broadsheet_write_reg(par, 0x0106, 0x0203);

    err = broadsheet_setup_spi(par);
    if (err)
        return err;

    err = broadsheet_setup_spiflash(par, initial_sfmcd);
    if (err)
        return err;

    return broadsheet_verify_spiflash(par, flash_type);
}

static int broadsheet_spiflash_write_control(struct broadsheetfb_par *par,
                        int mode)
{
    int err;

    broadsheet_write_reg(par, 0x0208, 1);
    if (mode)
        err = broadsheet_spiflash_write_byte(par, 0x06);
    else
        err = broadsheet_spiflash_write_byte(par, 0x04);

    broadsheet_write_reg(par, 0x0208, 0);
    return err;
}

static int broadsheet_spiflash_erase_sector(struct broadsheetfb_par *par,
                        int addr)
{
    int err;

    broadsheet_spiflash_write_control(par, 1);

    err = broadsheet_spiflash_op_on_address(par, 0xD8, addr);

    broadsheet_write_reg(par, 0x0208, 0);

    if (err)
        return err;

    err = broadsheet_spiflash_wait_for_status(par, 1000);

    return err;
}

static int broadsheet_spiflash_read_range(struct broadsheetfb_par *par,
                        int addr, int size, char *data)
{
    int err;
    int i;

    err = broadsheet_spiflash_op_on_address(par, 0x03, addr);
    if (err)
        goto failout;

    for (i = 0; i < size; i++) {
        err = broadsheet_spiflash_read_byte(par, &data[i]);
        if (err)
            goto failout;
    }

failout:
    broadsheet_write_reg(par, 0x0208, 0);
    return err;
}

#define BS_SPIFLASH_PAGE_SIZE 256
static int broadsheet_spiflash_write_page(struct broadsheetfb_par *par,
                        int addr, const char *data)
{
    int err;
    int i;

    broadsheet_spiflash_write_control(par, 1);

    err = broadsheet_spiflash_op_on_address(par, 0x02, addr);
    if (err)
        goto failout;

    for (i = 0; i < BS_SPIFLASH_PAGE_SIZE; i++) {
        err = broadsheet_spiflash_write_byte(par, data[i]);
        if (err)
            goto failout;
    }

    broadsheet_write_reg(par, 0x0208, 0);

    err = broadsheet_spiflash_wait_for_status(par, 100);

failout:
    return err;
}

static int broadsheet_spiflash_write_sector(struct broadsheetfb_par *par,
                int addr, const char *data, int sector_size)
{
    int i;
    int err;

    for (i = 0; i < sector_size; i += BS_SPIFLASH_PAGE_SIZE) {
        err = broadsheet_spiflash_write_page(par, addr + i, &data[i]);
        if (err)
            return err;
    }
    return 0;
}

/*
 * The caller must guarantee that the data to be rewritten is entirely
 * contained within this sector. That is, data_start_addr + data_len
 * must be less than sector_start_addr + sector_size.
 */
static int broadsheet_spiflash_rewrite_sector(struct broadsheetfb_par *par,
                    int sector_size, int data_start_addr,
                    int data_len, const char *data)
{
    int err;
    char *sector_buffer;
    int tail_start_addr;
    int start_sector_addr;

    sector_buffer = kzalloc(sizeof(char)*sector_size, GFP_KERNEL);
    if (!sector_buffer)
        return -ENOMEM;

    /* the start address of the sector is the 0th byte of that sector */
    start_sector_addr = (data_start_addr / sector_size) * sector_size;

    /*
     * check if there is head data that we need to readback into our sector
     * buffer first
     */
    if (data_start_addr != start_sector_addr) {
        /*
         * we need to read every byte up till the start address of our
         * data and we put it into our sector buffer.
         */
        err = broadsheet_spiflash_read_range(par, start_sector_addr,
                        data_start_addr, sector_buffer);
        if (err)
            return err;
    }

    /* now we copy our data into the right place in the sector buffer */
    memcpy(sector_buffer + data_start_addr, data, data_len);

    /*
     * now we check if there is a tail section of the sector that we need to
     * readback.
     */
    tail_start_addr = (data_start_addr + data_len) % sector_size;

    if (tail_start_addr) {
        int tail_len;

        tail_len = sector_size - tail_start_addr;

        /* now we read this tail into our sector buffer */
        err = broadsheet_spiflash_read_range(par, tail_start_addr,
            tail_len, sector_buffer + tail_start_addr);
        if (err)
            return err;
    }

    /* if we got here we have the full sector that we want to rewrite. */

    /* first erase the sector */
    err = broadsheet_spiflash_erase_sector(par, start_sector_addr);
    if (err)
        return err;

    /* now write it */
    err = broadsheet_spiflash_write_sector(par, start_sector_addr,
                    sector_buffer, sector_size);
    return err;
}

static int broadsheet_write_spiflash(struct broadsheetfb_par *par, u32 wfm_addr,
                const u8 *wfm, int bytecount, int flash_type)
{
    int sector_size;
    int err;
    int cur_addr;
    int writecount;
    int maxlen;
    int offset = 0;

    switch (flash_type) {
    case 0x10:
        sector_size = 32*1024;
        break;
    case 0x11:
    default:
        sector_size = 64*1024;
        break;
    }

    while (bytecount) {
        cur_addr = wfm_addr + offset;
        maxlen = roundup(cur_addr, sector_size) - cur_addr;
        writecount = min(bytecount, maxlen);

        err = broadsheet_spiflash_rewrite_sector(par, sector_size,
                cur_addr, writecount, wfm + offset);
        if (err)
            return err;

        offset += writecount;
        bytecount -= writecount;
    }

    return 0;
}

static int broadsheet_store_waveform_to_spiflash(struct broadsheetfb_par *par,
                        const u8 *wfm, size_t wfm_size)
{
    int err = 0;
    u16 initial_sfmcd = 0;
    int flash_type = 0;

    err = broadsheet_setup_for_wfm_write(par, &initial_sfmcd, &flash_type);
    if (err)
        goto failout;

    err = broadsheet_write_spiflash(par, 0x886, wfm, wfm_size, flash_type);

failout:
    broadsheet_write_reg(par, 0x0204, initial_sfmcd);
    return err;
}

static ssize_t broadsheet_loadstore_waveform(struct device *dev,
                        struct device_attribute *attr,
                        const char *buf, size_t len)
{
    int err;
    struct fb_info *info = dev_get_drvdata(dev);
    struct broadsheetfb_par *par = info->par;
    const struct firmware *fw_entry;

    if (len < 1)
        return -EINVAL;

    err = request_firmware(&fw_entry, "broadsheet.wbf", dev);
    if (err < 0) {
        dev_err(dev, "Failed to get broadsheet waveform\n");
        goto err_failed;
    }

    /* try to enforce reasonable min max on waveform */
    if ((fw_entry->size < 8*1024) || (fw_entry->size > 64*1024)) {
        dev_err(dev, "Invalid waveform\n");
        err = -EINVAL;
        goto err_failed;
    }

    mutex_lock(&(par->io_lock));
    err = broadsheet_store_waveform_to_spiflash(par, fw_entry->data,
                            fw_entry->size);

    mutex_unlock(&(par->io_lock));
    if (err < 0) {
        dev_err(dev, "Failed to store broadsheet waveform\n");
        goto err_failed;
    }

    dev_info(dev, "Stored broadsheet waveform, size %zd\n", fw_entry->size);

    return len;

err_failed:
    return err;
}
static DEVICE_ATTR(loadstore_waveform, S_IWUSR, NULL,
            broadsheet_loadstore_waveform);

/* upper level functions that manipulate the display and other stuff */
static void __devinit broadsheet_init_display(struct broadsheetfb_par *par)
{
    u16 args[5];
    int xres = par->info->var.xres;
    int yres = par->info->var.yres;

    args[0] = panel_table[par->panel_index].w;
    args[1] = panel_table[par->panel_index].h;
    args[2] = panel_table[par->panel_index].sdcfg;
    args[3] = panel_table[par->panel_index].gdcfg;
    args[4] = panel_table[par->panel_index].lutfmt;
    broadsheet_send_cmdargs(par, BS_CMD_INIT_DSPE_CFG, 5, args);

    /* did the controller really set it? */
    broadsheet_send_cmdargs(par, BS_CMD_INIT_DSPE_CFG, 5, args);

    args[0] = panel_table[par->panel_index].fsynclen;
    args[1] = panel_table[par->panel_index].fendfbegin;
    args[2] = panel_table[par->panel_index].lsynclen;
    args[3] = panel_table[par->panel_index].lendlbegin;
    args[4] = panel_table[par->panel_index].pixclk;
    broadsheet_send_cmdargs(par, BS_CMD_INIT_DSPE_TMG, 5, args);

    broadsheet_write_reg32(par, 0x310, xres*yres*2);

    /* setup waveform */
    args[0] = 0x886;
    args[1] = 0;
    broadsheet_send_cmdargs(par, BS_CMD_RD_WFM_INFO, 2, args);

    broadsheet_send_command(par, BS_CMD_UPD_GDRV_CLR);

    broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);

    broadsheet_write_reg(par, 0x330, 0x84);

    broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);

    args[0] = (0x3 << 4);
    broadsheet_send_cmdargs(par, BS_CMD_LD_IMG, 1, args);

    args[0] = 0x154;
    broadsheet_send_cmdargs(par, BS_CMD_WR_REG, 1, args);

    broadsheet_burst_write(par, (panel_table[par->panel_index].w *
                    panel_table[par->panel_index].h)/2,
                    (u16 *) par->info->screen_base);

    broadsheet_send_command(par, BS_CMD_LD_IMG_END);

    args[0] = 0x4300;
    broadsheet_send_cmdargs(par, BS_CMD_UPD_FULL, 1, args);

    broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);

    broadsheet_send_command(par, BS_CMD_WAIT_DSPE_FREND);

    par->board->wait_for_rdy(par);
}

static void __devinit broadsheet_identify(struct broadsheetfb_par *par)
{
    u16 rev, prc;
    struct device *dev = par->info->device;

    rev = broadsheet_read_reg(par, BS_REG_REV);
    prc = broadsheet_read_reg(par, BS_REG_PRC);
    dev_info(dev, "Broadsheet Rev 0x%x, Product Code 0x%x\n", rev, prc);

    if (prc != 0x0047)
        dev_warn(dev, "Unrecognized Broadsheet Product Code\n");
    if (rev != 0x0100)
        dev_warn(dev, "Unrecognized Broadsheet Revision\n");
}

static void __devinit broadsheet_init(struct broadsheetfb_par *par)
{
    broadsheet_send_command(par, BS_CMD_INIT_SYS_RUN);
    /* the controller needs a second */
    msleep(1000);
    broadsheet_init_display(par);
}

static void broadsheetfb_dpy_update_pages(struct broadsheetfb_par *par,
                        u16 y1, u16 y2)
{
    u16 args[5];
    unsigned char *buf = (unsigned char *)par->info->screen_base;

    mutex_lock(&(par->io_lock));
    /* y1 must be a multiple of 4 so drop the lower bits */
    y1 &= 0xFFFC;
    /* y2 must be a multiple of 4 , but - 1 so up the lower bits */
    y2 |= 0x0003;

    args[0] = 0x3 << 4;
    args[1] = 0;
    args[2] = y1;
    args[3] = cpu_to_le16(par->info->var.xres);
    args[4] = y2;
    broadsheet_send_cmdargs(par, BS_CMD_LD_IMG_AREA, 5, args);

    args[0] = 0x154;
    broadsheet_send_cmdargs(par, BS_CMD_WR_REG, 1, args);

    buf += y1 * par->info->var.xres;
    broadsheet_burst_write(par, ((1 + y2 - y1) * par->info->var.xres)/2,
                (u16 *) buf);

    broadsheet_send_command(par, BS_CMD_LD_IMG_END);

    args[0] = 0x4300;
    broadsheet_send_cmdargs(par, BS_CMD_UPD_FULL, 1, args);

    broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);

    broadsheet_send_command(par, BS_CMD_WAIT_DSPE_FREND);

    par->board->wait_for_rdy(par);
    mutex_unlock(&(par->io_lock));

}

static void broadsheetfb_dpy_update(struct broadsheetfb_par *par)
{
    u16 args[5];

    mutex_lock(&(par->io_lock));
    args[0] = 0x3 << 4;
    broadsheet_send_cmdargs(par, BS_CMD_LD_IMG, 1, args);

    args[0] = 0x154;
    broadsheet_send_cmdargs(par, BS_CMD_WR_REG, 1, args);
    broadsheet_burst_write(par, (panel_table[par->panel_index].w *
                    panel_table[par->panel_index].h)/2,
                    (u16 *) par->info->screen_base);

    broadsheet_send_command(par, BS_CMD_LD_IMG_END);

    args[0] = 0x4300;
    broadsheet_send_cmdargs(par, BS_CMD_UPD_FULL, 1, args);

    broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);

    broadsheet_send_command(par, BS_CMD_WAIT_DSPE_FREND);

    par->board->wait_for_rdy(par);
    mutex_unlock(&(par->io_lock));
}

/* this is called back from the deferred io workqueue */
static void broadsheetfb_dpy_deferred_io(struct fb_info *info,
                struct list_head *pagelist)
{
    u16 y1 = 0, h = 0;
    int prev_index = -1;
    struct page *cur;
    struct fb_deferred_io *fbdefio = info->fbdefio;
    int h_inc;
    u16 yres = info->var.yres;
    u16 xres = info->var.xres;

    /* height increment is fixed per page */
    h_inc = DIV_ROUND_UP(PAGE_SIZE , xres);

    /* walk the written page list and swizzle the data */
    list_for_each_entry(cur, &fbdefio->pagelist, lru) {
        if (prev_index < 0) {
            /* just starting so assign first page */
            y1 = (cur->index << PAGE_SHIFT) / xres;
            h = h_inc;
        } else if ((prev_index + 1) == cur->index) {
            /* this page is consecutive so increase our height */
            h += h_inc;
        } else {
            /* page not consecutive, issue previous update first */
            broadsheetfb_dpy_update_pages(info->par, y1, y1 + h);
            /* start over with our non consecutive page */
            y1 = (cur->index << PAGE_SHIFT) / xres;
            h = h_inc;
        }
        prev_index = cur->index;
    }

    /* if we still have any pages to update we do so now */
    if (h >= yres) {
        /* its a full screen update, just do it */
        broadsheetfb_dpy_update(info->par);
    } else {
        broadsheetfb_dpy_update_pages(info->par, y1,
                        min((u16) (y1 + h), yres));
    }
}

static void broadsheetfb_fillrect(struct fb_info *info,
                   const struct fb_fillrect *rect)
{
    struct broadsheetfb_par *par = info->par;

    sys_fillrect(info, rect);

    broadsheetfb_dpy_update(par);
}

static void broadsheetfb_copyarea(struct fb_info *info,
                   const struct fb_copyarea *area)
{
    struct broadsheetfb_par *par = info->par;

    sys_copyarea(info, area);

    broadsheetfb_dpy_update(par);
}

static void broadsheetfb_imageblit(struct fb_info *info,
                const struct fb_image *image)
{
    struct broadsheetfb_par *par = info->par;

    sys_imageblit(info, image);

    broadsheetfb_dpy_update(par);
}

/*
 * this is the slow path from userspace. they can seek and write to
 * the fb. it's inefficient to do anything less than a full screen draw
 */
static ssize_t broadsheetfb_write(struct fb_info *info, const char __user *buf,
                size_t count, loff_t *ppos)
{
    struct broadsheetfb_par *par = info->par;
    unsigned long p = *ppos;
    void *dst;
    int err = 0;
    unsigned long total_size;

    if (info->state != FBINFO_STATE_RUNNING)
        return -EPERM;

    total_size = info->fix.smem_len;

    if (p > total_size)
        return -EFBIG;

    if (count > total_size) {
        err = -EFBIG;
        count = total_size;
    }

    if (count + p > total_size) {
        if (!err)
            err = -ENOSPC;

        count = total_size - p;
    }

    dst = (void *)(info->screen_base + p);

    if (copy_from_user(dst, buf, count))
        err = -EFAULT;

    if  (!err)
        *ppos += count;

    broadsheetfb_dpy_update(par);

    return (err) ? err : count;
}

static struct fb_ops broadsheetfb_ops = {
    .owner      = THIS_MODULE,
    .fb_read        = fb_sys_read,
    .fb_write   = broadsheetfb_write,
    .fb_fillrect    = broadsheetfb_fillrect,
    .fb_copyarea    = broadsheetfb_copyarea,
    .fb_imageblit   = broadsheetfb_imageblit,
};

static struct fb_deferred_io broadsheetfb_defio = {
    .delay      = HZ/4,
    .deferred_io    = broadsheetfb_dpy_deferred_io,
};

static int __devinit broadsheetfb_probe(struct platform_device *dev)
{
    struct fb_info *info;
    struct broadsheet_board *board;
    int retval = -ENOMEM;
    int videomemorysize;
    unsigned char *videomemory;
    struct broadsheetfb_par *par;
    int i;
    int dpyw, dpyh;
    int panel_index;

    /* pick up board specific routines */
    board = dev->dev.platform_data;
    if (!board)
        return -EINVAL;

    /* try to count device specific driver, if can't, platform recalls */
    if (!try_module_get(board->owner))
        return -ENODEV;

    info = framebuffer_alloc(sizeof(struct broadsheetfb_par), &dev->dev);
    if (!info)
        goto err;

    switch (board->get_panel_type()) {
    case 37:
        panel_index = 1;
        break;
    case 97:
        panel_index = 2;
        break;
    case 6:
    default:
        panel_index = 0;
        break;
    }

    dpyw = panel_table[panel_index].w;
    dpyh = panel_table[panel_index].h;

    videomemorysize = roundup((dpyw*dpyh), PAGE_SIZE);

    videomemory = vzalloc(videomemorysize);
    if (!videomemory)
        goto err_fb_rel;

    info->screen_base = (char *)videomemory;
    info->fbops = &broadsheetfb_ops;

    broadsheetfb_var.xres = dpyw;
    broadsheetfb_var.yres = dpyh;
    broadsheetfb_var.xres_virtual = dpyw;
    broadsheetfb_var.yres_virtual = dpyh;
    info->var = broadsheetfb_var;

    broadsheetfb_fix.line_length = dpyw;
    info->fix = broadsheetfb_fix;
    info->fix.smem_len = videomemorysize;
    par = info->par;
    par->panel_index = panel_index;
    par->info = info;
    par->board = board;
    par->write_reg = broadsheet_write_reg;
    par->read_reg = broadsheet_read_reg;
    init_waitqueue_head(&par->waitq);

    mutex_init(&par->io_lock);

    info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;

    info->fbdefio = &broadsheetfb_defio;
    fb_deferred_io_init(info);

    retval = fb_alloc_cmap(&info->cmap, 16, 0);
    if (retval < 0) {
        dev_err(&dev->dev, "Failed to allocate colormap\n");
        goto err_vfree;
    }

    /* set cmap */
    for (i = 0; i < 16; i++)
        info->cmap.red[i] = (((2*i)+1)*(0xFFFF))/32;
    memcpy(info->cmap.green, info->cmap.red, sizeof(u16)*16);
    memcpy(info->cmap.blue, info->cmap.red, sizeof(u16)*16);

    retval = par->board->setup_irq(info);
    if (retval < 0)
        goto err_cmap;

    /* this inits the dpy */
    retval = board->init(par);
    if (retval < 0)
        goto err_free_irq;

    broadsheet_identify(par);

    broadsheet_init(par);

    retval = register_framebuffer(info);
    if (retval < 0)
        goto err_free_irq;

    platform_set_drvdata(dev, info);

    retval = device_create_file(&dev->dev, &dev_attr_loadstore_waveform);
    if (retval < 0)
        goto err_unreg_fb;

    printk(KERN_INFO
           "fb%d: Broadsheet frame buffer, using %dK of video memory\n",
           info->node, videomemorysize >> 10);


    return 0;

err_unreg_fb:
    unregister_framebuffer(info);
err_free_irq:
    board->cleanup(par);
err_cmap:
    fb_dealloc_cmap(&info->cmap);
err_vfree:
    vfree(videomemory);
err_fb_rel:
    framebuffer_release(info);
err:
    module_put(board->owner);
    return retval;

}

static int __devexit broadsheetfb_remove(struct platform_device *dev)
{
    struct fb_info *info = platform_get_drvdata(dev);

    if (info) {
        struct broadsheetfb_par *par = info->par;

        device_remove_file(info->dev, &dev_attr_loadstore_waveform);
        unregister_framebuffer(info);
        fb_deferred_io_cleanup(info);
        par->board->cleanup(par);
        fb_dealloc_cmap(&info->cmap);
        vfree((void *)info->screen_base);
        module_put(par->board->owner);
        framebuffer_release(info);
    }
    return 0;
}

static struct platform_driver broadsheetfb_driver = {
    .probe  = broadsheetfb_probe,
    .remove = __devexit_p(broadsheetfb_remove),
    .driver = {
        .owner  = THIS_MODULE,
        .name   = "broadsheetfb",
    },
};

static int __init broadsheetfb_init(void)
{
    return platform_driver_register(&broadsheetfb_driver);
}

static void __exit broadsheetfb_exit(void)
{
    platform_driver_unregister(&broadsheetfb_driver);
}

module_init(broadsheetfb_init);
module_exit(broadsheetfb_exit);

MODULE_DESCRIPTION("fbdev driver for Broadsheet controller");
MODULE_AUTHOR("Jaya Kumar");
MODULE_LICENSE("GPL");