/*
 * Common code for AUO-K190X framebuffer drivers
 *
 * Copyright (C) 2012 Heiko Stuebner <heiko@sntech.de>
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/fb.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/regulator/consumer.h>

#include <video/auo_k190xfb.h>

#include "auo_k190x.h"

struct panel_info {
        int w;
        int h;
};

/* table of panel specific parameters to be indexed into by the board drivers */
static struct panel_info panel_table[] = {
        /* standard 6" */
        [AUOK190X_RESOLUTION_800_600] = {
                .w = 800,
                .h = 600,
        },
        /* standard 9" */
        [AUOK190X_RESOLUTION_1024_768] = {
                .w = 1024,
                .h = 768,
        },
        [AUOK190X_RESOLUTION_600_800] = {
                .w = 600,
                .h = 800,
        },
        [AUOK190X_RESOLUTION_768_1024] = {
                .w = 768,
                .h = 1024,
        },
};

/*
 * private I80 interface to the board driver
 */

static void auok190x_issue_data(struct auok190xfb_par *par, u16 data)
{
        par->board->set_ctl(par, AUOK190X_I80_WR, 0);
        par->board->set_hdb(par, data);
        par->board->set_ctl(par, AUOK190X_I80_WR, 1);
}

static void auok190x_issue_cmd(struct auok190xfb_par *par, u16 data)
{
        par->board->set_ctl(par, AUOK190X_I80_DC, 0);
        auok190x_issue_data(par, data);
        par->board->set_ctl(par, AUOK190X_I80_DC, 1);
}

/**
 * Conversion of 16bit color to 4bit grayscale
 * does roughly (0.3 * R + 0.6 G + 0.1 B) / 2
 */
static inline int rgb565_to_gray4(u16 data, struct fb_var_screeninfo *var)
{
        return ((((data & 0xF800) >> var->red.offset) * 77 +
                 ((data & 0x07E0) >> (var->green.offset + 1)) * 151 +
                 ((data & 0x1F) >> var->blue.offset) * 28) >> 8 >> 1);
}

static int auok190x_issue_pixels_rgb565(struct auok190xfb_par *par, int size,
                                        u16 *data)
{
        struct fb_var_screeninfo *var = &par->info->var;
        struct device *dev = par->info->device;
        int i;
        u16 tmp;

        if (size & 7) {
                dev_err(dev, "issue_pixels: size %d must be a multiple of 8\n",
                        size);
                return -EINVAL;
        }

        for (i = 0; i < (size >> 2); i++) {
                par->board->set_ctl(par, AUOK190X_I80_WR, 0);

                tmp  = (rgb565_to_gray4(data[4*i], var) & 0x000F);
                tmp |= (rgb565_to_gray4(data[4*i+1], var) << 4) & 0x00F0;
                tmp |= (rgb565_to_gray4(data[4*i+2], var) << 8) & 0x0F00;
                tmp |= (rgb565_to_gray4(data[4*i+3], var) << 12) & 0xF000;

                par->board->set_hdb(par, tmp);
                par->board->set_ctl(par, AUOK190X_I80_WR, 1);
        }

        return 0;
}

static int auok190x_issue_pixels_gray8(struct auok190xfb_par *par, int size,
                                       u16 *data)
{
        struct device *dev = par->info->device;
        int i;
        u16 tmp;

        if (size & 3) {
                dev_err(dev, "issue_pixels: size %d must be a multiple of 4\n",
                        size);
                return -EINVAL;
        }

        for (i = 0; i < (size >> 1); i++) {
                par->board->set_ctl(par, AUOK190X_I80_WR, 0);

                /* simple reduction of 8bit staticgray to 4bit gray
                 * combines 4 * 4bit pixel values into a 16bit value
                 */
                tmp  = (data[2*i] & 0xF0) >> 4;
                tmp |= (data[2*i] & 0xF000) >> 8;
                tmp |= (data[2*i+1] & 0xF0) << 4;
                tmp |= (data[2*i+1] & 0xF000);

                par->board->set_hdb(par, tmp);
                par->board->set_ctl(par, AUOK190X_I80_WR, 1);
        }

        return 0;
}

static int auok190x_issue_pixels(struct auok190xfb_par *par, int size,
                                 u16 *data)
{
        struct fb_info *info = par->info;
        struct device *dev = par->info->device;

        if (info->var.bits_per_pixel == 8 && info->var.grayscale)
                auok190x_issue_pixels_gray8(par, size, data);
        else if (info->var.bits_per_pixel == 16)
                auok190x_issue_pixels_rgb565(par, size, data);
        else
                dev_err(dev, "unsupported color mode (bits: %d, gray: %d)\n",
                        info->var.bits_per_pixel, info->var.grayscale);

        return 0;
}

static u16 auok190x_read_data(struct auok190xfb_par *par)
{
        u16 data;

        par->board->set_ctl(par, AUOK190X_I80_OE, 0);
        data = par->board->get_hdb(par);
        par->board->set_ctl(par, AUOK190X_I80_OE, 1);

        return data;
}

/*
 * Command interface for the controller drivers
 */

void auok190x_send_command_nowait(struct auok190xfb_par *par, u16 data)
{
        par->board->set_ctl(par, AUOK190X_I80_CS, 0);
        auok190x_issue_cmd(par, data);
        par->board->set_ctl(par, AUOK190X_I80_CS, 1);
}
EXPORT_SYMBOL_GPL(auok190x_send_command_nowait);

void auok190x_send_cmdargs_nowait(struct auok190xfb_par *par, u16 cmd,
                                  int argc, u16 *argv)
{
        int i;

        par->board->set_ctl(par, AUOK190X_I80_CS, 0);
        auok190x_issue_cmd(par, cmd);

        for (i = 0; i < argc; i++)
                auok190x_issue_data(par, argv[i]);
        par->board->set_ctl(par, AUOK190X_I80_CS, 1);
}
EXPORT_SYMBOL_GPL(auok190x_send_cmdargs_nowait);

int auok190x_send_command(struct auok190xfb_par *par, u16 data)
{
        int ret;

        ret = par->board->wait_for_rdy(par);
        if (ret)
                return ret;

        auok190x_send_command_nowait(par, data);
        return 0;
}
EXPORT_SYMBOL_GPL(auok190x_send_command);

int auok190x_send_cmdargs(struct auok190xfb_par *par, u16 cmd,
                           int argc, u16 *argv)
{
        int ret;

        ret = par->board->wait_for_rdy(par);
        if (ret)
                return ret;

        auok190x_send_cmdargs_nowait(par, cmd, argc, argv);
        return 0;
}
EXPORT_SYMBOL_GPL(auok190x_send_cmdargs);

int auok190x_read_cmdargs(struct auok190xfb_par *par, u16 cmd,
                           int argc, u16 *argv)
{
        int i, ret;

        ret = par->board->wait_for_rdy(par);
        if (ret)
                return ret;

        par->board->set_ctl(par, AUOK190X_I80_CS, 0);
        auok190x_issue_cmd(par, cmd);

        for (i = 0; i < argc; i++)
                argv[i] = auok190x_read_data(par);
        par->board->set_ctl(par, AUOK190X_I80_CS, 1);

        return 0;
}
EXPORT_SYMBOL_GPL(auok190x_read_cmdargs);

void auok190x_send_cmdargs_pixels_nowait(struct auok190xfb_par *par, u16 cmd,
                                  int argc, u16 *argv, int size, u16 *data)
{
        int i;

        par->board->set_ctl(par, AUOK190X_I80_CS, 0);

        auok190x_issue_cmd(par, cmd);

        for (i = 0; i < argc; i++)
                auok190x_issue_data(par, argv[i]);

        auok190x_issue_pixels(par, size, data);

        par->board->set_ctl(par, AUOK190X_I80_CS, 1);
}
EXPORT_SYMBOL_GPL(auok190x_send_cmdargs_pixels_nowait);

int auok190x_send_cmdargs_pixels(struct auok190xfb_par *par, u16 cmd,
                                  int argc, u16 *argv, int size, u16 *data)
{
        int ret;

        ret = par->board->wait_for_rdy(par);
        if (ret)
                return ret;

        auok190x_send_cmdargs_pixels_nowait(par, cmd, argc, argv, size, data);

        return 0;
}
EXPORT_SYMBOL_GPL(auok190x_send_cmdargs_pixels);

/*
 * fbdefio callbacks - common on both controllers.
 */

static void auok190xfb_dpy_first_io(struct fb_info *info)
{
        /* tell runtime-pm that we wish to use the device in a short time */
        pm_runtime_get(info->device);
}

/* this is called back from the deferred io workqueue */
static void auok190xfb_dpy_deferred_io(struct fb_info *info,
                                struct list_head *pagelist)
{
        struct fb_deferred_io *fbdefio = info->fbdefio;
        struct auok190xfb_par *par = info->par;
        u16 line_length = info->fix.line_length;
        u16 yres = info->var.yres;
        u16 y1 = 0, h = 0;
        int prev_index = -1;
        struct page *cur;
        int h_inc;
        int threshold;

        if (!list_empty(pagelist))
                /* the device resume should've been requested through first_io,
                 * if the resume did not finish until now, wait for it.
                 */
                pm_runtime_barrier(info->device);
        else
                /* We reached this via the fsync or some other way.
                 * In either case the first_io function did not run,
                 * so we runtime_resume the device here synchronously.
                 */
                pm_runtime_get_sync(info->device);

        /* Do a full screen update every n updates to prevent
         * excessive darkening of the Sipix display.
         * If we do this, there is no need to walk the pages.
         */
        if (par->need_refresh(par)) {
                par->update_all(par);
                goto out;
        }

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

        /* calculate number of pages from pixel height */
        threshold = par->consecutive_threshold / h_inc;
        if (threshold < 1)
                threshold = 1;

        /* 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) / line_length;
                        h = h_inc;
                } else if ((cur->index - prev_index) <= threshold) {
                        /* page is within our threshold for single updates */
                        h += h_inc * (cur->index - prev_index);
                } else {
                        /* page not consecutive, issue previous update first */
                        par->update_partial(par, y1, y1 + h);

                        /* start over with our non consecutive page */
                        y1 = (cur->index << PAGE_SHIFT) / line_length;
                        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 */
                par->update_all(par);
        else
                par->update_partial(par, y1, min((u16) (y1 + h), yres));

out:
        pm_runtime_mark_last_busy(info->device);
        pm_runtime_put_autosuspend(info->device);
}

/*
 * framebuffer operations
 */

/*
 * 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 auok190xfb_write(struct fb_info *info, const char __user *buf,
                                size_t count, loff_t *ppos)
{
        struct auok190xfb_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;

        par->update_all(par);

        return (err) ? err : count;
}

static void auok190xfb_fillrect(struct fb_info *info,
                                   const struct fb_fillrect *rect)
{
        struct auok190xfb_par *par = info->par;

        sys_fillrect(info, rect);

        par->update_all(par);
}

static void auok190xfb_copyarea(struct fb_info *info,
                                   const struct fb_copyarea *area)
{
        struct auok190xfb_par *par = info->par;

        sys_copyarea(info, area);

        par->update_all(par);
}

static void auok190xfb_imageblit(struct fb_info *info,
                                const struct fb_image *image)
{
        struct auok190xfb_par *par = info->par;

        sys_imageblit(info, image);

        par->update_all(par);
}

static int auok190xfb_check_var(struct fb_var_screeninfo *var,
                                   struct fb_info *info)
{
        struct device *dev = info->device;
        struct auok190xfb_par *par = info->par;
        struct panel_info *panel = &panel_table[par->resolution];
        int size;

        /*
         * Color depth
         */

        if (var->bits_per_pixel == 8 && var->grayscale == 1) {
                /*
                 * For 8-bit grayscale, R, G, and B offset are equal.
                 */
                var->red.length = 8;
                var->red.offset = 0;
                var->red.msb_right = 0;

                var->green.length = 8;
                var->green.offset = 0;
                var->green.msb_right = 0;

                var->blue.length = 8;
                var->blue.offset = 0;
                var->blue.msb_right = 0;

                var->transp.length = 0;
                var->transp.offset = 0;
                var->transp.msb_right = 0;
        } else if (var->bits_per_pixel == 16) {
                var->red.length = 5;
                var->red.offset = 11;
                var->red.msb_right = 0;

                var->green.length = 6;
                var->green.offset = 5;
                var->green.msb_right = 0;

                var->blue.length = 5;
                var->blue.offset = 0;
                var->blue.msb_right = 0;

                var->transp.length = 0;
                var->transp.offset = 0;
                var->transp.msb_right = 0;
        } else {
                dev_warn(dev, "unsupported color mode (bits: %d, grayscale: %d)\n",
                        info->var.bits_per_pixel, info->var.grayscale);
                return -EINVAL;
        }

        /*
         * Dimensions
         */

        switch (var->rotate) {
        case FB_ROTATE_UR:
        case FB_ROTATE_UD:
                var->xres = panel->w;
                var->yres = panel->h;
                break;
        case FB_ROTATE_CW:
        case FB_ROTATE_CCW:
                var->xres = panel->h;
                var->yres = panel->w;
                break;
        default:
                dev_dbg(dev, "Invalid rotation request\n");
                return -EINVAL;
        }

        var->xres_virtual = var->xres;
        var->yres_virtual = var->yres;

        /*
         *  Memory limit
         */

        size = var->xres_virtual * var->yres_virtual * var->bits_per_pixel / 8;
        if (size > info->fix.smem_len) {
                dev_err(dev, "Memory limit exceeded, requested %dK\n",
                        size >> 10);
                return -ENOMEM;
        }

        return 0;
}

static int auok190xfb_set_fix(struct fb_info *info)
{
        struct fb_fix_screeninfo *fix = &info->fix;
        struct fb_var_screeninfo *var = &info->var;

        fix->line_length = var->xres_virtual * var->bits_per_pixel / 8;

        fix->type = FB_TYPE_PACKED_PIXELS;
        fix->accel = FB_ACCEL_NONE;
        fix->visual = (var->grayscale) ? FB_VISUAL_STATIC_PSEUDOCOLOR
                                       : FB_VISUAL_TRUECOLOR;
        fix->xpanstep = 0;
        fix->ypanstep = 0;
        fix->ywrapstep = 0;

        return 0;
}

static int auok190xfb_set_par(struct fb_info *info)
{
        struct auok190xfb_par *par = info->par;

        par->rotation = info->var.rotate;
        auok190xfb_set_fix(info);

        /* reinit the controller to honor the rotation */
        par->init(par);

        /* wait for init to complete */
        par->board->wait_for_rdy(par);

        return 0;
}

static struct fb_ops auok190xfb_ops = {
        .owner          = THIS_MODULE,
        .fb_read        = fb_sys_read,
        .fb_write       = auok190xfb_write,
        .fb_fillrect    = auok190xfb_fillrect,
        .fb_copyarea    = auok190xfb_copyarea,
        .fb_imageblit   = auok190xfb_imageblit,
        .fb_check_var   = auok190xfb_check_var,
        .fb_set_par     = auok190xfb_set_par,
};

/*
 * Controller-functions common to both K1900 and K1901
 */

static int auok190x_read_temperature(struct auok190xfb_par *par)
{
        struct device *dev = par->info->device;
        u16 data[4];
        int temp;

        pm_runtime_get_sync(dev);

        mutex_lock(&(par->io_lock));

        auok190x_read_cmdargs(par, AUOK190X_CMD_READ_VERSION, 4, data);

        mutex_unlock(&(par->io_lock));

        pm_runtime_mark_last_busy(dev);
        pm_runtime_put_autosuspend(dev);

        /* sanitize and split of half-degrees for now */
        temp = ((data[0] & AUOK190X_VERSION_TEMP_MASK) >> 1);

        /* handle positive and negative temperatures */
        if (temp >= 201)
                return (255 - temp + 1) * (-1);
        else
                return temp;
}

static void auok190x_identify(struct auok190xfb_par *par)
{
        struct device *dev = par->info->device;
        u16 data[4];

        pm_runtime_get_sync(dev);

        mutex_lock(&(par->io_lock));

        auok190x_read_cmdargs(par, AUOK190X_CMD_READ_VERSION, 4, data);

        mutex_unlock(&(par->io_lock));

        par->epd_type = data[1] & AUOK190X_VERSION_TEMP_MASK;

        par->panel_size_int = AUOK190X_VERSION_SIZE_INT(data[2]);
        par->panel_size_float = AUOK190X_VERSION_SIZE_FLOAT(data[2]);
        par->panel_model = AUOK190X_VERSION_MODEL(data[2]);

        par->tcon_version = AUOK190X_VERSION_TCON(data[3]);
        par->lut_version = AUOK190X_VERSION_LUT(data[3]);

        dev_dbg(dev, "panel %d.%din, model 0x%x, EPD 0x%x TCON-rev 0x%x, LUT-rev 0x%x",
                par->panel_size_int, par->panel_size_float, par->panel_model,
                par->epd_type, par->tcon_version, par->lut_version);

        pm_runtime_mark_last_busy(dev);
        pm_runtime_put_autosuspend(dev);
}

/*
 * Sysfs functions
 */

static ssize_t update_mode_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct fb_info *info = dev_get_drvdata(dev);
        struct auok190xfb_par *par = info->par;

        return sprintf(buf, "%d\n", par->update_mode);
}

static ssize_t update_mode_store(struct device *dev,
                                 struct device_attribute *attr,
                                 const char *buf, size_t count)
{
        struct fb_info *info = dev_get_drvdata(dev);
        struct auok190xfb_par *par = info->par;
        int mode, ret;

        ret = kstrtoint(buf, 10, &mode);
        if (ret)
                return ret;

        par->update_mode = mode;

        /* if we enter a better mode, do a full update */
        if (par->last_mode > 1 && mode < par->last_mode)
                par->update_all(par);

        return count;
}

static ssize_t flash_show(struct device *dev, struct device_attribute *attr,
                          char *buf)
{
        struct fb_info *info = dev_get_drvdata(dev);
        struct auok190xfb_par *par = info->par;

        return sprintf(buf, "%d\n", par->flash);
}

static ssize_t flash_store(struct device *dev, struct device_attribute *attr,
                           const char *buf, size_t count)
{
        struct fb_info *info = dev_get_drvdata(dev);
        struct auok190xfb_par *par = info->par;
        int flash, ret;

        ret = kstrtoint(buf, 10, &flash);
        if (ret)
                return ret;

        if (flash > 0)
                par->flash = 1;
        else
                par->flash = 0;

        return count;
}

static ssize_t temp_show(struct device *dev, struct device_attribute *attr,
                         char *buf)
{
        struct fb_info *info = dev_get_drvdata(dev);
        struct auok190xfb_par *par = info->par;
        int temp;

        temp = auok190x_read_temperature(par);
        return sprintf(buf, "%d\n", temp);
}

static DEVICE_ATTR(update_mode, 0644, update_mode_show, update_mode_store);
static DEVICE_ATTR(flash, 0644, flash_show, flash_store);
static DEVICE_ATTR(temp, 0644, temp_show, NULL);

static struct attribute *auok190x_attributes[] = {
        &dev_attr_update_mode.attr,
        &dev_attr_flash.attr,
        &dev_attr_temp.attr,
        NULL
};

static const struct attribute_group auok190x_attr_group = {
        .attrs          = auok190x_attributes,
};

static int auok190x_power(struct auok190xfb_par *par, bool on)
{
        struct auok190x_board *board = par->board;
        int ret;

        if (on) {
                /* We should maintain POWER up for at least 80ms before set
                 * RST_N and SLP_N to high (TCON spec 20100803_v35 p59)
                 */
                ret = regulator_enable(par->regulator);
                if (ret)
                        return ret;

                msleep(200);
                gpio_set_value(board->gpio_nrst, 1);
                gpio_set_value(board->gpio_nsleep, 1);
                msleep(200);
        } else {
                regulator_disable(par->regulator);
                gpio_set_value(board->gpio_nrst, 0);
                gpio_set_value(board->gpio_nsleep, 0);
        }

        return 0;
}

/*
 * Recovery - powercycle the controller
 */

static void auok190x_recover(struct auok190xfb_par *par)
{
        struct device *dev = par->info->device;

        auok190x_power(par, 0);
        msleep(100);
        auok190x_power(par, 1);

        /* after powercycling the device, it's always active */
        pm_runtime_set_active(dev);
        par->standby = 0;

        par->init(par);

        /* wait for init to complete */
        par->board->wait_for_rdy(par);
}

/*
 * Power-management
 */

#ifdef CONFIG_PM
static int auok190x_runtime_suspend(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct fb_info *info = platform_get_drvdata(pdev);
        struct auok190xfb_par *par = info->par;
        struct auok190x_board *board = par->board;
        u16 standby_param;

        /* take and keep the lock until we are resumed, as the controller
         * will never reach the non-busy state when in standby mode
         */
        mutex_lock(&(par->io_lock));

        if (par->standby) {
                dev_warn(dev, "already in standby, runtime-pm pairing mismatch\n");
                mutex_unlock(&(par->io_lock));
                return 0;
        }

        /* according to runtime_pm.txt runtime_suspend only means, that the
         * device will not process data and will not communicate with the CPU
         * As we hold the lock, this stays true even without standby
         */
        if (board->quirks & AUOK190X_QUIRK_STANDBYBROKEN) {
                dev_dbg(dev, "runtime suspend without standby\n");
                goto finish;
        } else if (board->quirks & AUOK190X_QUIRK_STANDBYPARAM) {
                /* for some TCON versions STANDBY expects a parameter (0) but
                 * it seems the real tcon version has to be determined yet.
                 */
                dev_dbg(dev, "runtime suspend with additional empty param\n");
                standby_param = 0;
                auok190x_send_cmdargs(par, AUOK190X_CMD_STANDBY, 1,
                                      &standby_param);
        } else {
                dev_dbg(dev, "runtime suspend without param\n");
                auok190x_send_command(par, AUOK190X_CMD_STANDBY);
        }

        msleep(64);

finish:
        par->standby = 1;

        return 0;
}

static int auok190x_runtime_resume(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct fb_info *info = platform_get_drvdata(pdev);
        struct auok190xfb_par *par = info->par;
        struct auok190x_board *board = par->board;

        if (!par->standby) {
                dev_warn(dev, "not in standby, runtime-pm pairing mismatch\n");
                return 0;
        }

        if (board->quirks & AUOK190X_QUIRK_STANDBYBROKEN) {
                dev_dbg(dev, "runtime resume without standby\n");
        } else {
                /* when in standby, controller is always busy
                 * and only accepts the wakeup command
                 */
                dev_dbg(dev, "runtime resume from standby\n");
                auok190x_send_command_nowait(par, AUOK190X_CMD_WAKEUP);

                msleep(160);

                /* wait for the controller to be ready and release the lock */
                board->wait_for_rdy(par);
        }

        par->standby = 0;

        mutex_unlock(&(par->io_lock));

        return 0;
}

static int auok190x_suspend(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct fb_info *info = platform_get_drvdata(pdev);
        struct auok190xfb_par *par = info->par;
        struct auok190x_board *board = par->board;
        int ret;

        dev_dbg(dev, "suspend\n");
        if (board->quirks & AUOK190X_QUIRK_STANDBYBROKEN) {
                /* suspend via powering off the ic */
                dev_dbg(dev, "suspend with broken standby\n");

                auok190x_power(par, 0);
        } else {
                dev_dbg(dev, "suspend using sleep\n");

                /* the sleep state can only be entered from the standby state.
                 * pm_runtime_get_noresume gets called before the suspend call.
                 * So the devices usage count is >0 but it is not necessarily
                 * active.
                 */
                if (!pm_runtime_status_suspended(dev)) {
                        ret = auok190x_runtime_suspend(dev);
                        if (ret < 0) {
                                dev_err(dev, "auok190x_runtime_suspend failed with %d\n",
                                        ret);
                                return ret;
                        }
                        par->manual_standby = 1;
                }

                gpio_direction_output(board->gpio_nsleep, 0);
        }

        msleep(100);

        return 0;
}

static int auok190x_resume(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct fb_info *info = platform_get_drvdata(pdev);
        struct auok190xfb_par *par = info->par;
        struct auok190x_board *board = par->board;

        dev_dbg(dev, "resume\n");
        if (board->quirks & AUOK190X_QUIRK_STANDBYBROKEN) {
                dev_dbg(dev, "resume with broken standby\n");

                auok190x_power(par, 1);

                par->init(par);
        } else {
                dev_dbg(dev, "resume from sleep\n");

                /* device should be in runtime suspend when we were suspended
                 * and pm_runtime_put_sync gets called after this function.
                 * So there is no need to touch the standby mode here at all.
                 */
                gpio_direction_output(board->gpio_nsleep, 1);
                msleep(100);

                /* an additional init call seems to be necessary after sleep */
                auok190x_runtime_resume(dev);
                par->init(par);

                /* if we were runtime-suspended before, suspend again*/
                if (!par->manual_standby)
                        auok190x_runtime_suspend(dev);
                else
                        par->manual_standby = 0;
        }

        return 0;
}
#endif

const struct dev_pm_ops auok190x_pm = {
        SET_RUNTIME_PM_OPS(auok190x_runtime_suspend, auok190x_runtime_resume,
                           NULL)
        SET_SYSTEM_SLEEP_PM_OPS(auok190x_suspend, auok190x_resume)
};
EXPORT_SYMBOL_GPL(auok190x_pm);

/*
 * Common probe and remove code
 */

int auok190x_common_probe(struct platform_device *pdev,
                          struct auok190x_init_data *init)
{
        struct auok190x_board *board = init->board;
        struct auok190xfb_par *par;
        struct fb_info *info;
        struct panel_info *panel;
        int videomemorysize, ret;
        unsigned char *videomemory;

        /* check board contents */
        if (!board->init || !board->cleanup || !board->wait_for_rdy
            || !board->set_ctl || !board->set_hdb || !board->get_hdb
            || !board->setup_irq)
                return -EINVAL;

        info = framebuffer_alloc(sizeof(struct auok190xfb_par), &pdev->dev);
        if (!info)
                return -ENOMEM;

        par = info->par;
        par->info = info;
        par->board = board;
        par->recover = auok190x_recover;
        par->update_partial = init->update_partial;
        par->update_all = init->update_all;
        par->need_refresh = init->need_refresh;
        par->init = init->init;

        /* init update modes */
        par->update_cnt = 0;
        par->update_mode = -1;
        par->last_mode = -1;
        par->flash = 0;

        par->regulator = regulator_get(info->device, "vdd");
        if (IS_ERR(par->regulator)) {
                ret = PTR_ERR(par->regulator);
                dev_err(info->device, "Failed to get regulator: %d\n", ret);
                goto err_reg;
        }

        ret = board->init(par);
        if (ret) {
                dev_err(info->device, "board init failed, %d\n", ret);
                goto err_board;
        }

        ret = gpio_request(board->gpio_nsleep, "AUOK190x sleep");
        if (ret) {
                dev_err(info->device, "could not request sleep gpio, %d\n",
                        ret);

                goto err_gpio1;
        }

        ret = gpio_direction_output(board->gpio_nsleep, 0);
        if (ret) {
                dev_err(info->device, "could not set sleep gpio, %d\n", ret);
                goto err_gpio2;
        }

        ret = gpio_request(board->gpio_nrst, "AUOK190x reset");
        if (ret) {
                dev_err(info->device, "could not request reset gpio, %d\n",
                        ret);
                goto err_gpio2;
        }

        ret = gpio_direction_output(board->gpio_nrst, 0);
        if (ret) {
                dev_err(info->device, "could not set reset gpio, %d\n", ret);
                goto err_gpio3;
        }

        ret = auok190x_power(par, 1);
        if (ret) {
                dev_err(info->device, "could not power on the device, %d\n",
                        ret);
                goto err_gpio3;
        }

        mutex_init(&par->io_lock);

        init_waitqueue_head(&par->waitq);

        ret = par->board->setup_irq(par->info);
        if (ret) {
                dev_err(info->device, "could not setup ready-irq, %d\n", ret);
                goto err_irq;
        }

        /* wait for init to complete */
        par->board->wait_for_rdy(par);

        /*
         * From here on the controller can talk to us
         */

        /* initialise fix, var, resolution and rotation */

        strlcpy(info->fix.id, init->id, 16);
        info->var.bits_per_pixel = 8;
        info->var.grayscale = 1;

        panel = &panel_table[board->resolution];

        par->resolution = board->resolution;
        par->rotation = 0;

        /* videomemory handling */

        videomemorysize = roundup((panel->w * panel->h) * 2, PAGE_SIZE);
        videomemory = vmalloc(videomemorysize);
        if (!videomemory) {
                ret = -ENOMEM;
                goto err_irq;
        }

        memset(videomemory, 0, videomemorysize);
        info->screen_base = (char *)videomemory;
        info->fix.smem_len = videomemorysize;

        info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
        info->fbops = &auok190xfb_ops;

        ret = auok190xfb_check_var(&info->var, info);
        if (ret)
                goto err_defio;

        auok190xfb_set_fix(info);

        /* deferred io init */

        info->fbdefio = devm_kzalloc(info->device,
                                     sizeof(struct fb_deferred_io),
                                     GFP_KERNEL);
        if (!info->fbdefio) {
                dev_err(info->device, "Failed to allocate memory\n");
                ret = -ENOMEM;
                goto err_defio;
        }

        dev_dbg(info->device, "targeting %d frames per second\n", board->fps);
        info->fbdefio->delay = HZ / board->fps;
        info->fbdefio->first_io = auok190xfb_dpy_first_io,
        info->fbdefio->deferred_io = auok190xfb_dpy_deferred_io,
        fb_deferred_io_init(info);

        /* color map */

        ret = fb_alloc_cmap(&info->cmap, 256, 0);
        if (ret < 0) {
                dev_err(info->device, "Failed to allocate colormap\n");
                goto err_cmap;
        }

        /* controller init */

        par->consecutive_threshold = 100;
        par->init(par);
        auok190x_identify(par);

        platform_set_drvdata(pdev, info);

        ret = register_framebuffer(info);
        if (ret < 0)
                goto err_regfb;

        ret = sysfs_create_group(&info->device->kobj, &auok190x_attr_group);
        if (ret)
                goto err_sysfs;

        dev_info(info->device, "fb%d: %dx%d using %dK of video memory\n",
                 info->node, info->var.xres, info->var.yres,
                 videomemorysize >> 10);

        /* increase autosuspend_delay when we use alternative methods
         * for runtime_pm
         */
        par->autosuspend_delay = (board->quirks & AUOK190X_QUIRK_STANDBYBROKEN)
                                        ? 1000 : 200;

        pm_runtime_set_active(info->device);
        pm_runtime_enable(info->device);
        pm_runtime_set_autosuspend_delay(info->device, par->autosuspend_delay);
        pm_runtime_use_autosuspend(info->device);

        return 0;

err_sysfs:
        unregister_framebuffer(info);
err_regfb:
        fb_dealloc_cmap(&info->cmap);
err_cmap:
        fb_deferred_io_cleanup(info);
err_defio:
        vfree((void *)info->screen_base);
err_irq:
        auok190x_power(par, 0);
err_gpio3:
        gpio_free(board->gpio_nrst);
err_gpio2:
        gpio_free(board->gpio_nsleep);
err_gpio1:
        board->cleanup(par);
err_board:
        regulator_put(par->regulator);
err_reg:
        framebuffer_release(info);

        return ret;
}
EXPORT_SYMBOL_GPL(auok190x_common_probe);

int  auok190x_common_remove(struct platform_device *pdev)
{
        struct fb_info *info = platform_get_drvdata(pdev);
        struct auok190xfb_par *par = info->par;
        struct auok190x_board *board = par->board;

        pm_runtime_disable(info->device);

        sysfs_remove_group(&info->device->kobj, &auok190x_attr_group);

        unregister_framebuffer(info);

        fb_dealloc_cmap(&info->cmap);

        fb_deferred_io_cleanup(info);

        vfree((void *)info->screen_base);

        auok190x_power(par, 0);

        gpio_free(board->gpio_nrst);
        gpio_free(board->gpio_nsleep);

        board->cleanup(par);

        regulator_put(par->regulator);

        framebuffer_release(info);

        return 0;
}
EXPORT_SYMBOL_GPL(auok190x_common_remove);

MODULE_DESCRIPTION("Common code for AUO-K190X controllers");
MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
MODULE_LICENSE("GPL");