/*
 * am200epd.c -- Platform device for AM200 EPD kit
 *
 * 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 work was made possible by help and equipment support from E-Ink
 * Corporation. http://support.eink.com/community
 *
 * This driver is written to be used with the Metronome display controller.
 * on the AM200 EPD prototype kit/development kit with an E-Ink 800x600
 * Vizplex EPD on a Gumstix board using the Lyre interface board.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/irq.h>
#include <linux/gpio.h>

#include "pxa25x.h"
#include "gumstix.h"
#include <linux/platform_data/video-pxafb.h>

#include "generic.h"

#include <video/metronomefb.h>

static unsigned int panel_type = 6;
static struct platform_device *am200_device;
static struct metronome_board am200_board;

static struct pxafb_mode_info am200_fb_mode_9inch7 = {
        .pixclock       = 40000,
        .xres           = 1200,
        .yres           = 842,
        .bpp            = 16,
        .hsync_len      = 2,
        .left_margin    = 2,
        .right_margin   = 2,
        .vsync_len      = 1,
        .upper_margin   = 2,
        .lower_margin   = 25,
        .sync           = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
};

static struct pxafb_mode_info am200_fb_mode_8inch = {
        .pixclock       = 40000,
        .xres           = 1088,
        .yres           = 791,
        .bpp            = 16,
        .hsync_len      = 28,
        .left_margin    = 8,
        .right_margin   = 30,
        .vsync_len      = 8,
        .upper_margin   = 10,
        .lower_margin   = 8,
        .sync           = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
};

static struct pxafb_mode_info am200_fb_mode_6inch = {
        .pixclock       = 40189,
        .xres           = 832,
        .yres           = 622,
        .bpp            = 16,
        .hsync_len      = 28,
        .left_margin    = 34,
        .right_margin   = 34,
        .vsync_len      = 25,
        .upper_margin   = 0,
        .lower_margin   = 2,
        .sync           = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
};

static struct pxafb_mach_info am200_fb_info = {
        .modes          = &am200_fb_mode_6inch,
        .num_modes      = 1,
        .lcd_conn       = LCD_TYPE_COLOR_TFT | LCD_PCLK_EDGE_FALL |
                          LCD_AC_BIAS_FREQ(24),
};

/* register offsets for gpio control */
#define LED_GPIO_PIN 51
#define STDBY_GPIO_PIN 48
#define RST_GPIO_PIN 49
#define RDY_GPIO_PIN 32
#define ERR_GPIO_PIN 17
#define PCBPWR_GPIO_PIN 16
static int gpios[] = { LED_GPIO_PIN , STDBY_GPIO_PIN , RST_GPIO_PIN,
                        RDY_GPIO_PIN, ERR_GPIO_PIN, PCBPWR_GPIO_PIN };
static char *gpio_names[] = { "LED" , "STDBY" , "RST", "RDY", "ERR", "PCBPWR" };

static int am200_init_gpio_regs(struct metronomefb_par *par)
{
        int i;
        int err;

        for (i = 0; i < ARRAY_SIZE(gpios); i++) {
                err = gpio_request(gpios[i], gpio_names[i]);
                if (err) {
                        dev_err(&am200_device->dev, "failed requesting "
                                "gpio %s, err=%d\n", gpio_names[i], err);
                        goto err_req_gpio;
                }
        }

        gpio_direction_output(LED_GPIO_PIN, 0);
        gpio_direction_output(STDBY_GPIO_PIN, 0);
        gpio_direction_output(RST_GPIO_PIN, 0);

        gpio_direction_input(RDY_GPIO_PIN);
        gpio_direction_input(ERR_GPIO_PIN);

        gpio_direction_output(PCBPWR_GPIO_PIN, 0);

        return 0;

err_req_gpio:
        while (--i >= 0)
                gpio_free(gpios[i]);

        return err;
}

static void am200_cleanup(struct metronomefb_par *par)
{
        int i;

        free_irq(PXA_GPIO_TO_IRQ(RDY_GPIO_PIN), par);

        for (i = 0; i < ARRAY_SIZE(gpios); i++)
                gpio_free(gpios[i]);
}

static int am200_share_video_mem(struct fb_info *info)
{
        /* rough check if this is our desired fb and not something else */
        if ((info->var.xres != am200_fb_info.modes->xres)
                || (info->var.yres != am200_fb_info.modes->yres))
                return 0;

        /* we've now been notified that we have our new fb */
        am200_board.metromem = info->screen_base;
        am200_board.host_fbinfo = info;

        /* try to refcount host drv since we are the consumer after this */
        if (!try_module_get(info->fbops->owner))
                return -ENODEV;

        return 0;
}

static int am200_unshare_video_mem(struct fb_info *info)
{
        dev_dbg(&am200_device->dev, "ENTER %s\n", __func__);

        if (info != am200_board.host_fbinfo)
                return 0;

        module_put(am200_board.host_fbinfo->fbops->owner);
        return 0;
}

static int am200_fb_notifier_callback(struct notifier_block *self,
                                 unsigned long event, void *data)
{
        struct fb_event *evdata = data;
        struct fb_info *info = evdata->info;

        dev_dbg(&am200_device->dev, "ENTER %s\n", __func__);

        if (event == FB_EVENT_FB_REGISTERED)
                return am200_share_video_mem(info);
        else if (event == FB_EVENT_FB_UNREGISTERED)
                return am200_unshare_video_mem(info);

        return 0;
}

static struct notifier_block am200_fb_notif = {
        .notifier_call = am200_fb_notifier_callback,
};

/* this gets called as part of our init. these steps must be done now so
 * that we can use pxa_set_fb_info */
static void __init am200_presetup_fb(void)
{
        int fw;
        int fh;
        int padding_size;
        int totalsize;

        switch (panel_type) {
        case 6:
                am200_fb_info.modes = &am200_fb_mode_6inch;
                break;
        case 8:
                am200_fb_info.modes = &am200_fb_mode_8inch;
                break;
        case 97:
                am200_fb_info.modes = &am200_fb_mode_9inch7;
                break;
        default:
                dev_err(&am200_device->dev, "invalid panel_type selection,"
                                                " setting to 6\n");
                am200_fb_info.modes = &am200_fb_mode_6inch;
                break;
        }

        /* the frame buffer is divided as follows:
        command | CRC | padding
        16kb waveform data | CRC | padding
        image data | CRC
        */

        fw = am200_fb_info.modes->xres;
        fh = am200_fb_info.modes->yres;

        /* waveform must be 16k + 2 for checksum */
        am200_board.wfm_size = roundup(16*1024 + 2, fw);

        padding_size = PAGE_SIZE + (4 * fw);

        /* total is 1 cmd , 1 wfm, padding and image */
        totalsize = fw + am200_board.wfm_size + padding_size + (fw*fh);

        /* save this off because we're manipulating fw after this and
         * we'll need it when we're ready to setup the framebuffer */
        am200_board.fw = fw;
        am200_board.fh = fh;

        /* the reason we do this adjustment is because we want to acquire
         * more framebuffer memory without imposing custom awareness on the
         * underlying pxafb driver */
        am200_fb_info.modes->yres = DIV_ROUND_UP(totalsize, fw);

        /* we divide since we told the LCD controller we're 16bpp */
        am200_fb_info.modes->xres /= 2;

        pxa_set_fb_info(NULL, &am200_fb_info);

}

/* this gets called by metronomefb as part of its init, in our case, we
 * have already completed initial framebuffer init in presetup_fb so we
 * can just setup the fb access pointers */
static int am200_setup_fb(struct metronomefb_par *par)
{
        int fw;
        int fh;

        fw = am200_board.fw;
        fh = am200_board.fh;

        /* metromem was set up by the notifier in share_video_mem so now
         * we can use its value to calculate the other entries */
        par->metromem_cmd = (struct metromem_cmd *) am200_board.metromem;
        par->metromem_wfm = am200_board.metromem + fw;
        par->metromem_img = par->metromem_wfm + am200_board.wfm_size;
        par->metromem_img_csum = (u16 *) (par->metromem_img + (fw * fh));
        par->metromem_dma = am200_board.host_fbinfo->fix.smem_start;

        return 0;
}

static int am200_get_panel_type(void)
{
        return panel_type;
}

static irqreturn_t am200_handle_irq(int irq, void *dev_id)
{
        struct metronomefb_par *par = dev_id;

        wake_up_interruptible(&par->waitq);
        return IRQ_HANDLED;
}

static int am200_setup_irq(struct fb_info *info)
{
        int ret;

        ret = request_irq(PXA_GPIO_TO_IRQ(RDY_GPIO_PIN), am200_handle_irq,
                                IRQF_TRIGGER_FALLING, "AM200", info->par);
        if (ret)
                dev_err(&am200_device->dev, "request_irq failed: %d\n", ret);

        return ret;
}

static void am200_set_rst(struct metronomefb_par *par, int state)
{
        gpio_set_value(RST_GPIO_PIN, state);
}

static void am200_set_stdby(struct metronomefb_par *par, int state)
{
        gpio_set_value(STDBY_GPIO_PIN, state);
}

static int am200_wait_event(struct metronomefb_par *par)
{
        return wait_event_timeout(par->waitq, gpio_get_value(RDY_GPIO_PIN), HZ);
}

static int am200_wait_event_intr(struct metronomefb_par *par)
{
        return wait_event_interruptible_timeout(par->waitq,
                                        gpio_get_value(RDY_GPIO_PIN), HZ);
}

static struct metronome_board am200_board = {
        .owner                  = THIS_MODULE,
        .setup_irq              = am200_setup_irq,
        .setup_io               = am200_init_gpio_regs,
        .setup_fb               = am200_setup_fb,
        .set_rst                = am200_set_rst,
        .set_stdby              = am200_set_stdby,
        .met_wait_event         = am200_wait_event,
        .met_wait_event_intr    = am200_wait_event_intr,
        .get_panel_type         = am200_get_panel_type,
        .cleanup                = am200_cleanup,
};

static unsigned long am200_pin_config[] __initdata = {
        GPIO51_GPIO,
        GPIO49_GPIO,
        GPIO48_GPIO,
        GPIO32_GPIO,
        GPIO17_GPIO,
        GPIO16_GPIO,
};

int __init am200_init(void)
{
        int ret;

        /*
         * Before anything else, we request notification for any fb
         * creation events.
         *
         * FIXME: This is terrible and needs to be nuked. The notifier is used
         * to get at the fb base address from the boot splash fb driver, which
         * is then passed to metronomefb. Instaed of metronomfb or this board
         * support file here figuring this out on their own.
         *
         * See also the #ifdef in fbmem.c.
         */
        fb_register_client(&am200_fb_notif);

        pxa2xx_mfp_config(ARRAY_AND_SIZE(am200_pin_config));

        /* request our platform independent driver */
        request_module("metronomefb");

        am200_device = platform_device_alloc("metronomefb", -1);
        if (!am200_device)
                return -ENOMEM;

        /* the am200_board that will be seen by metronomefb is a copy */
        platform_device_add_data(am200_device, &am200_board,
                                        sizeof(am200_board));

        /* this _add binds metronomefb to am200. metronomefb refcounts am200 */
        ret = platform_device_add(am200_device);

        if (ret) {
                platform_device_put(am200_device);
                fb_unregister_client(&am200_fb_notif);
                return ret;
        }

        am200_presetup_fb();

        return 0;
}

module_param(panel_type, uint, 0);
MODULE_PARM_DESC(panel_type, "Select the panel type: 6, 8, 97");

MODULE_DESCRIPTION("board driver for am200 metronome epd kit");
MODULE_AUTHOR("Jaya Kumar");
MODULE_LICENSE("GPL");