/*
 * auok190xfb.c -- FB driver for AUO-K1900 controllers
 *
 * Copyright (C) 2011, 2012 Heiko Stuebner <heiko@sntech.de>
 *
 * based on broadsheetfb.c
 *
 * Copyright (C) 2008, Jaya Kumar
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
 *
 * This driver is written to be used with the AUO-K1900 display controller.
 *
 * It is intended to be architecture independent. A board specific driver
 * must be used to perform all the physical IO interactions.
 *
 * The controller supports different update modes:
 * mode0+1 16 step gray (4bit)
 * mode2 4 step gray (2bit) - FIXME: add strange refresh
 * mode3 2 step gray (1bit) - FIXME: add strange refresh
 * mode4 handwriting mode (strange behaviour)
 * mode5 automatic selection of update mode
 */

#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/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/gpio.h>
#include <linux/pm_runtime.h>

#include <video/auo_k190xfb.h>

#include "auo_k190x.h"

/*
 * AUO-K1900 specific commands
 */

#define AUOK1900_CMD_PARTIALDISP        0x1001
#define AUOK1900_CMD_ROTATION           0x1006
#define AUOK1900_CMD_LUT_STOP           0x1009

#define AUOK1900_INIT_TEMP_AVERAGE      (1 << 13)
#define AUOK1900_INIT_ROTATE(_x)        ((_x & 0x3) << 10)
#define AUOK1900_INIT_RESOLUTION(_res)  ((_res & 0x7) << 2)

static void auok1900_init(struct auok190xfb_par *par)
{
        struct device *dev = par->info->device;
        struct auok190x_board *board = par->board;
        u16 init_param = 0;

        pm_runtime_get_sync(dev);

        init_param |= AUOK1900_INIT_TEMP_AVERAGE;
        init_param |= AUOK1900_INIT_ROTATE(par->rotation);
        init_param |= AUOK190X_INIT_INVERSE_WHITE;
        init_param |= AUOK190X_INIT_FORMAT0;
        init_param |= AUOK1900_INIT_RESOLUTION(par->resolution);
        init_param |= AUOK190X_INIT_SHIFT_RIGHT;

        auok190x_send_cmdargs(par, AUOK190X_CMD_INIT, 1, &init_param);

        /* let the controller finish */
        board->wait_for_rdy(par);

        pm_runtime_mark_last_busy(dev);
        pm_runtime_put_autosuspend(dev);
}

static void auok1900_update_region(struct auok190xfb_par *par, int mode,
                                                u16 y1, u16 y2)
{
        struct device *dev = par->info->device;
        unsigned char *buf = (unsigned char *)par->info->screen_base;
        int xres = par->info->var.xres;
        int line_length = par->info->fix.line_length;
        u16 args[4];

        pm_runtime_get_sync(dev);

        mutex_lock(&(par->io_lock));

        /* y1 and y2 must be a multiple of 2 so drop the lowest bit */
        y1 &= 0xfffe;
        y2 &= 0xfffe;

        dev_dbg(dev, "update (x,y,w,h,mode)=(%d,%d,%d,%d,%d)\n",
                1, y1+1, xres, y2-y1, mode);

        /* to FIX handle different partial update modes */
        args[0] = mode | 1;
        args[1] = y1 + 1;
        args[2] = xres;
        args[3] = y2 - y1;
        buf += y1 * line_length;
        auok190x_send_cmdargs_pixels(par, AUOK1900_CMD_PARTIALDISP, 4, args,
                                     ((y2 - y1) * line_length)/2, (u16 *) buf);
        auok190x_send_command(par, AUOK190X_CMD_DATA_STOP);

        par->update_cnt++;

        mutex_unlock(&(par->io_lock));

        pm_runtime_mark_last_busy(dev);
        pm_runtime_put_autosuspend(dev);
}

static void auok1900fb_dpy_update_pages(struct auok190xfb_par *par,
                                                u16 y1, u16 y2)
{
        int mode;

        if (par->update_mode < 0) {
                mode = AUOK190X_UPDATE_MODE(1);
                par->last_mode = -1;
        } else {
                mode = AUOK190X_UPDATE_MODE(par->update_mode);
                par->last_mode = par->update_mode;
        }

        if (par->flash)
                mode |= AUOK190X_UPDATE_NONFLASH;

        auok1900_update_region(par, mode, y1, y2);
}

static void auok1900fb_dpy_update(struct auok190xfb_par *par)
{
        int mode;

        if (par->update_mode < 0) {
                mode = AUOK190X_UPDATE_MODE(0);
                par->last_mode = -1;
        } else {
                mode = AUOK190X_UPDATE_MODE(par->update_mode);
                par->last_mode = par->update_mode;
        }

        if (par->flash)
                mode |= AUOK190X_UPDATE_NONFLASH;

        auok1900_update_region(par, mode, 0, par->info->var.yres);
        par->update_cnt = 0;
}

static bool auok1900fb_need_refresh(struct auok190xfb_par *par)
{
        return (par->update_cnt > 10);
}

static int auok1900fb_probe(struct platform_device *pdev)
{
        struct auok190x_init_data init;
        struct auok190x_board *board;

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

        /* fill temporary init struct for common init */
        init.id = "auo_k1900fb";
        init.board = board;
        init.update_partial = auok1900fb_dpy_update_pages;
        init.update_all = auok1900fb_dpy_update;
        init.need_refresh = auok1900fb_need_refresh;
        init.init = auok1900_init;

        return auok190x_common_probe(pdev, &init);
}

static int auok1900fb_remove(struct platform_device *pdev)
{
        return auok190x_common_remove(pdev);
}

static struct platform_driver auok1900fb_driver = {
        .probe  = auok1900fb_probe,
        .remove = auok1900fb_remove,
        .driver = {
                .owner  = THIS_MODULE,
                .name   = "auo_k1900fb",
                .pm = &auok190x_pm,
        },
};
module_platform_driver(auok1900fb_driver);

MODULE_DESCRIPTION("framebuffer driver for the AUO-K1900 EPD controller");
MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
MODULE_LICENSE("GPL");