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am200epd.c

/*
 * 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 <mach/pxafb.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(IRQ_GPIO(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 set_pxa_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;

      set_pxa_fb_info(&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(IRQ_GPIO(RDY_GPIO_PIN), am200_handle_irq,
                        IRQF_DISABLED|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 int __init am200_init(void)
{
      int ret;

      /* before anything else, we request notification for any fb
       * creation events */
      fb_register_client(&am200_fb_notif);

      /* 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_init(am200_init);

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

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