/*
 * 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 = {
        .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 = {
        .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(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)
                        goto out;
        }

        /* 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)
                        goto out;
        }

        /* 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)
                goto out;

        /* now write it */
        err = broadsheet_spiflash_write_sector(par, start_sector_addr,
                                        sector_buffer, sector_size);
out:
        kfree(sector_buffer);
        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_fw;
        }

        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_fw;
        }

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

        err = len;

err_fw:
        release_firmware(fw_entry);
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 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_buffer);

        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 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 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 = par->info->screen_buffer;

        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_buffer);

        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 *pagereflist)
{
        u16 y1 = 0, h = 0;
        unsigned long prev_offset = ULONG_MAX;
        struct fb_deferred_io_pageref *pageref;
        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(pageref, pagereflist, list) {
                if (prev_offset == ULONG_MAX) {
                        /* just starting so assign first page */
                        y1 = pageref->offset / xres;
                        h = h_inc;
                } else if ((prev_offset + PAGE_SIZE) == pageref->offset) {
                        /* 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 = pageref->offset / xres;
                        h = h_inc;
                }
                prev_offset = pageref->offset;
        }

        /* 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_defio_damage_range(struct fb_info *info, off_t off, size_t len)
{
        struct broadsheetfb_par *par = info->par;

        broadsheetfb_dpy_update(par);
}

static void broadsheetfb_defio_damage_area(struct fb_info *info, u32 x, u32 y,
                                           u32 width, u32 height)
{
        struct broadsheetfb_par *par = info->par;

        broadsheetfb_dpy_update(par);
}

FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(broadsheetfb,
                                   broadsheetfb_defio_damage_range,
                                   broadsheetfb_defio_damage_area)

static const struct fb_ops broadsheetfb_ops = {
        .owner  = THIS_MODULE,
        FB_DEFAULT_DEFERRED_OPS(broadsheetfb),
};

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

static int 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_buffer = 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_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;

        fb_info(info, "Broadsheet frame buffer, using %dK of video memory\n",
                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 void 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->device, &dev_attr_loadstore_waveform);
                unregister_framebuffer(info);
                fb_deferred_io_cleanup(info);
                par->board->cleanup(par);
                fb_dealloc_cmap(&info->cmap);
                vfree(info->screen_buffer);
                module_put(par->board->owner);
                framebuffer_release(info);
        }
}

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

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

MODULE_FIRMWARE("broadsheet.wbf");