/*
   * auok190xfb.c -- FB driver for AUO-K1901 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-K1901 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+3 4 step gray (2bit)
   * mode4+5 2 step gray (1bit)
   * - mode4 is described as "without LUT"
   * mode7 automatic selection of update mode
   *
   * The most interesting difference to the K1900 is the ability to do screen
   * updates in an asynchronous fashion. Where the K1900 needs to wait for the
   * current update to complete, the K1901 can process later updates already.
   */
  
  #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-K1901 specific commands
   */
  
  #define AUOK1901_CMD_LUT_INTERFACE	0x0005
  #define AUOK1901_CMD_DMA_START		0x1001
  #define AUOK1901_CMD_CURSOR_START	0x1007
  #define AUOK1901_CMD_CURSOR_STOP	AUOK190X_CMD_DATA_STOP
  #define AUOK1901_CMD_DDMA_START		0x1009
  
  #define AUOK1901_INIT_GATE_PULSE_LOW	(0 << 14)
  #define AUOK1901_INIT_GATE_PULSE_HIGH	(1 << 14)
  #define AUOK1901_INIT_SINGLE_GATE	(0 << 13)
  #define AUOK1901_INIT_DOUBLE_GATE	(1 << 13)
  
  /* Bits to pixels
   *   Mode	15-12	11-8	7-4	3-0
   *   format2	2	T	1	T
   *   format3	1	T	2	T
   *   format4	T	2	T	1
   *   format5	T	1	T	2
   *
   *   halftone modes:
   *   format6	2	2	1	1
   *   format7	1	1	2	2
   */
  #define AUOK1901_INIT_FORMAT2		(1 << 7)
  #define AUOK1901_INIT_FORMAT3		((1 << 7) | (1 << 6))
  #define AUOK1901_INIT_FORMAT4		(1 << 8)
  #define AUOK1901_INIT_FORMAT5		((1 << 8) | (1 << 6))
  #define AUOK1901_INIT_FORMAT6		((1 << 8) | (1 << 7))
  #define AUOK1901_INIT_FORMAT7		((1 << 8) | (1 << 7) | (1 << 6))
  
  /* res[4] to bit 10
   * res[3-0] to bits 5-2
   */
  #define AUOK1901_INIT_RESOLUTION(_res)	(((_res & (1 << 4)) << 6) \
  					 | ((_res & 0xf) << 2))
  
  /*
   * portrait / landscape orientation in AUOK1901_CMD_DMA_START
   */
  #define AUOK1901_DMA_ROTATE90(_rot)		((_rot & 1) << 13)
  
  /*
   * equivalent to 1 << 11, needs the ~ to have same rotation like K1900
   */
  #define AUOK1901_DDMA_ROTATE180(_rot)		((~_rot & 2) << 10)
  
  static void auok1901_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 |= AUOK190X_INIT_INVERSE_WHITE;
  	init_param |= AUOK190X_INIT_FORMAT0;
  	init_param |= AUOK1901_INIT_RESOLUTION(par->resolution);
  	init_param |= AUOK190X_INIT_SHIFT_LEFT;
  
  	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 auok1901_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[5];
  
  	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)
  ",
  		1, y1+1, xres, y2-y1, mode);
  
  	/* K1901: first transfer the region data */
  	args[0] = AUOK1901_DMA_ROTATE90(par->rotation) | 1;
  	args[1] = y1 + 1;
  	args[2] = xres;
  	args[3] = y2 - y1;
  	buf += y1 * line_length;
  	auok190x_send_cmdargs_pixels_nowait(par, AUOK1901_CMD_DMA_START, 4,
  					    args, ((y2 - y1) * line_length)/2,
  					    (u16 *) buf);
  	auok190x_send_command_nowait(par, AUOK190X_CMD_DATA_STOP);
  
  	/* K1901: second tell the controller to update the region with mode */
  	args[0] = mode | AUOK1901_DDMA_ROTATE180(par->rotation);
  	args[1] = 1;
  	args[2] = y1 + 1;
  	args[3] = xres;
  	args[4] = y2 - y1;
  	auok190x_send_cmdargs_nowait(par, AUOK1901_CMD_DDMA_START, 5, args);
  
  	par->update_cnt++;
  
  	mutex_unlock(&(par->io_lock));
  
  	pm_runtime_mark_last_busy(dev);
  	pm_runtime_put_autosuspend(dev);
  }
  
  static void auok1901fb_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;
  
  	auok1901_update_region(par, mode, y1, y2);
  }
  
  static void auok1901fb_dpy_update(struct auok190xfb_par *par)
  {
  	int mode;
  
  	/* When doing full updates, wait for the controller to be ready
  	 * This will hopefully catch some hangs of the K1901
  	 */
  	par->board->wait_for_rdy(par);
  
  	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;
  
  	auok1901_update_region(par, mode, 0, par->info->var.yres);
  	par->update_cnt = 0;
  }
  
  static bool auok1901fb_need_refresh(struct auok190xfb_par *par)
  {
  	return (par->update_cnt > 10);
  }
  
  static int auok1901fb_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_k1901fb";
  	init.board = board;
  	init.update_partial = auok1901fb_dpy_update_pages;
  	init.update_all = auok1901fb_dpy_update;
  	init.need_refresh = auok1901fb_need_refresh;
  	init.init = auok1901_init;
  
  	return auok190x_common_probe(pdev, &init);
  }
  
  static int auok1901fb_remove(struct platform_device *pdev)
  {
  	return auok190x_common_remove(pdev);
  }
  
  static struct platform_driver auok1901fb_driver = {
  	.probe	= auok1901fb_probe,
  	.remove = auok1901fb_remove,
  	.driver	= {
  		.owner	= THIS_MODULE,
  		.name	= "auo_k1901fb",
  		.pm = &auok190x_pm,
  	},
  };
  module_platform_driver(auok1901fb_driver);
  
  MODULE_DESCRIPTION("framebuffer driver for the AUO-K1901 EPD controller");
  MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
  MODULE_LICENSE("GPL");