am200epd.c

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/*
 * 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/pxa25x.h>
#include <mach/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_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 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 */
    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");