panel-acx565akm.c

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/*
 * Support for ACX565AKM LCD Panel used on Nokia N900
 *
 * Copyright (C) 2010 Nokia Corporation
 *
 * Original Driver Author: Imre Deak <[email protected]>
 * Based on panel-generic.c by Tomi Valkeinen <[email protected]>
 * Adapted to new DSS2 framework: Roger Quadros <[email protected]>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/spi/spi.h>
#include <linux/jiffies.h>
#include <linux/sched.h>
#include <linux/backlight.h>
#include <linux/fb.h>

#include <video/omapdss.h>

#define MIPID_CMD_READ_DISP_ID      0x04
#define MIPID_CMD_READ_RED      0x06
#define MIPID_CMD_READ_GREEN        0x07
#define MIPID_CMD_READ_BLUE     0x08
#define MIPID_CMD_READ_DISP_STATUS  0x09
#define MIPID_CMD_RDDSDR        0x0F
#define MIPID_CMD_SLEEP_IN      0x10
#define MIPID_CMD_SLEEP_OUT     0x11
#define MIPID_CMD_DISP_OFF      0x28
#define MIPID_CMD_DISP_ON       0x29
#define MIPID_CMD_WRITE_DISP_BRIGHTNESS 0x51
#define MIPID_CMD_READ_DISP_BRIGHTNESS  0x52
#define MIPID_CMD_WRITE_CTRL_DISP   0x53

#define CTRL_DISP_BRIGHTNESS_CTRL_ON    (1 << 5)
#define CTRL_DISP_AMBIENT_LIGHT_CTRL_ON (1 << 4)
#define CTRL_DISP_BACKLIGHT_ON      (1 << 2)
#define CTRL_DISP_AUTO_BRIGHTNESS_ON    (1 << 1)

#define MIPID_CMD_READ_CTRL_DISP    0x54
#define MIPID_CMD_WRITE_CABC        0x55
#define MIPID_CMD_READ_CABC     0x56

#define MIPID_VER_LPH8923       3
#define MIPID_VER_LS041Y3       4
#define MIPID_VER_L4F00311      8
#define MIPID_VER_ACX565AKM     9

struct acx565akm_device {
    char        *name;
    int     enabled;
    int     model;
    int     revision;
    u8      display_id[3];
    unsigned    has_bc:1;
    unsigned    has_cabc:1;
    unsigned    cabc_mode;
    unsigned long   hw_guard_end;       /* next value of jiffies
                           when we can issue the
                           next sleep in/out command */
    unsigned long   hw_guard_wait;      /* max guard time in jiffies */

    struct spi_device   *spi;
    struct mutex        mutex;

    struct omap_dss_device  *dssdev;
    struct backlight_device *bl_dev;
};

static struct acx565akm_device acx_dev;
static int acx565akm_bl_update_status(struct backlight_device *dev);

/*--------------------MIPID interface-----------------------------*/

static void acx565akm_transfer(struct acx565akm_device *md, int cmd,
                  const u8 *wbuf, int wlen, u8 *rbuf, int rlen)
{
    struct spi_message  m;
    struct spi_transfer *x, xfer[5];
    int         r;

    BUG_ON(md->spi == NULL);

    spi_message_init(&m);

    memset(xfer, 0, sizeof(xfer));
    x = &xfer[0];

    cmd &=  0xff;
    x->tx_buf = &cmd;
    x->bits_per_word = 9;
    x->len = 2;

    if (rlen > 1 && wlen == 0) {
        /*
         * Between the command and the response data there is a
         * dummy clock cycle. Add an extra bit after the command
         * word to account for this.
         */
        x->bits_per_word = 10;
        cmd <<= 1;
    }
    spi_message_add_tail(x, &m);

    if (wlen) {
        x++;
        x->tx_buf = wbuf;
        x->len = wlen;
        x->bits_per_word = 9;
        spi_message_add_tail(x, &m);
    }

    if (rlen) {
        x++;
        x->rx_buf   = rbuf;
        x->len      = rlen;
        spi_message_add_tail(x, &m);
    }

    r = spi_sync(md->spi, &m);
    if (r < 0)
        dev_dbg(&md->spi->dev, "spi_sync %d\n", r);
}

static inline void acx565akm_cmd(struct acx565akm_device *md, int cmd)
{
    acx565akm_transfer(md, cmd, NULL, 0, NULL, 0);
}

static inline void acx565akm_write(struct acx565akm_device *md,
                   int reg, const u8 *buf, int len)
{
    acx565akm_transfer(md, reg, buf, len, NULL, 0);
}

static inline void acx565akm_read(struct acx565akm_device *md,
                  int reg, u8 *buf, int len)
{
    acx565akm_transfer(md, reg, NULL, 0, buf, len);
}

static void hw_guard_start(struct acx565akm_device *md, int guard_msec)
{
    md->hw_guard_wait = msecs_to_jiffies(guard_msec);
    md->hw_guard_end = jiffies + md->hw_guard_wait;
}

static void hw_guard_wait(struct acx565akm_device *md)
{
    unsigned long wait = md->hw_guard_end - jiffies;

    if ((long)wait > 0 && wait <= md->hw_guard_wait) {
        set_current_state(TASK_UNINTERRUPTIBLE);
        schedule_timeout(wait);
    }
}

/*----------------------MIPID wrappers----------------------------*/

static void set_sleep_mode(struct acx565akm_device *md, int on)
{
    int cmd;

    if (on)
        cmd = MIPID_CMD_SLEEP_IN;
    else
        cmd = MIPID_CMD_SLEEP_OUT;
    /*
     * We have to keep 120msec between sleep in/out commands.
     * (8.2.15, 8.2.16).
     */
    hw_guard_wait(md);
    acx565akm_cmd(md, cmd);
    hw_guard_start(md, 120);
}

static void set_display_state(struct acx565akm_device *md, int enabled)
{
    int cmd = enabled ? MIPID_CMD_DISP_ON : MIPID_CMD_DISP_OFF;

    acx565akm_cmd(md, cmd);
}

static int panel_enabled(struct acx565akm_device *md)
{
    u32 disp_status;
    int enabled;

    acx565akm_read(md, MIPID_CMD_READ_DISP_STATUS, (u8 *)&disp_status, 4);
    disp_status = __be32_to_cpu(disp_status);
    enabled = (disp_status & (1 << 17)) && (disp_status & (1 << 10));
    dev_dbg(&md->spi->dev,
        "LCD panel %senabled by bootloader (status 0x%04x)\n",
        enabled ? "" : "not ", disp_status);
    return enabled;
}

static int panel_detect(struct acx565akm_device *md)
{
    acx565akm_read(md, MIPID_CMD_READ_DISP_ID, md->display_id, 3);
    dev_dbg(&md->spi->dev, "MIPI display ID: %02x%02x%02x\n",
        md->display_id[0], md->display_id[1], md->display_id[2]);

    switch (md->display_id[0]) {
    case 0x10:
        md->model = MIPID_VER_ACX565AKM;
        md->name = "acx565akm";
        md->has_bc = 1;
        md->has_cabc = 1;
        break;
    case 0x29:
        md->model = MIPID_VER_L4F00311;
        md->name = "l4f00311";
        break;
    case 0x45:
        md->model = MIPID_VER_LPH8923;
        md->name = "lph8923";
        break;
    case 0x83:
        md->model = MIPID_VER_LS041Y3;
        md->name = "ls041y3";
        break;
    default:
        md->name = "unknown";
        dev_err(&md->spi->dev, "invalid display ID\n");
        return -ENODEV;
    }

    md->revision = md->display_id[1];

    dev_info(&md->spi->dev, "omapfb: %s rev %02x LCD detected\n",
            md->name, md->revision);

    return 0;
}

/*----------------------Backlight Control-------------------------*/

static void enable_backlight_ctrl(struct acx565akm_device *md, int enable)
{
    u16 ctrl;

    acx565akm_read(md, MIPID_CMD_READ_CTRL_DISP, (u8 *)&ctrl, 1);
    if (enable) {
        ctrl |= CTRL_DISP_BRIGHTNESS_CTRL_ON |
            CTRL_DISP_BACKLIGHT_ON;
    } else {
        ctrl &= ~(CTRL_DISP_BRIGHTNESS_CTRL_ON |
              CTRL_DISP_BACKLIGHT_ON);
    }

    ctrl |= 1 << 8;
    acx565akm_write(md, MIPID_CMD_WRITE_CTRL_DISP, (u8 *)&ctrl, 2);
}

static void set_cabc_mode(struct acx565akm_device *md, unsigned mode)
{
    u16 cabc_ctrl;

    md->cabc_mode = mode;
    if (!md->enabled)
        return;
    cabc_ctrl = 0;
    acx565akm_read(md, MIPID_CMD_READ_CABC, (u8 *)&cabc_ctrl, 1);
    cabc_ctrl &= ~3;
    cabc_ctrl |= (1 << 8) | (mode & 3);
    acx565akm_write(md, MIPID_CMD_WRITE_CABC, (u8 *)&cabc_ctrl, 2);
}

static unsigned get_cabc_mode(struct acx565akm_device *md)
{
    return md->cabc_mode;
}

static unsigned get_hw_cabc_mode(struct acx565akm_device *md)
{
    u8 cabc_ctrl;

    acx565akm_read(md, MIPID_CMD_READ_CABC, &cabc_ctrl, 1);
    return cabc_ctrl & 3;
}

static void acx565akm_set_brightness(struct acx565akm_device *md, int level)
{
    int bv;

    bv = level | (1 << 8);
    acx565akm_write(md, MIPID_CMD_WRITE_DISP_BRIGHTNESS, (u8 *)&bv, 2);

    if (level)
        enable_backlight_ctrl(md, 1);
    else
        enable_backlight_ctrl(md, 0);
}

static int acx565akm_get_actual_brightness(struct acx565akm_device *md)
{
    u8 bv;

    acx565akm_read(md, MIPID_CMD_READ_DISP_BRIGHTNESS, &bv, 1);

    return bv;
}


static int acx565akm_bl_update_status(struct backlight_device *dev)
{
    struct acx565akm_device *md = dev_get_drvdata(&dev->dev);
    int r;
    int level;

    dev_dbg(&md->spi->dev, "%s\n", __func__);

    mutex_lock(&md->mutex);

    if (dev->props.fb_blank == FB_BLANK_UNBLANK &&
            dev->props.power == FB_BLANK_UNBLANK)
        level = dev->props.brightness;
    else
        level = 0;

    r = 0;
    if (md->has_bc)
        acx565akm_set_brightness(md, level);
    else if (md->dssdev->set_backlight)
        r = md->dssdev->set_backlight(md->dssdev, level);
    else
        r = -ENODEV;

    mutex_unlock(&md->mutex);

    return r;
}

static int acx565akm_bl_get_intensity(struct backlight_device *dev)
{
    struct acx565akm_device *md = dev_get_drvdata(&dev->dev);

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

    if (!md->has_bc && md->dssdev->set_backlight == NULL)
        return -ENODEV;

    if (dev->props.fb_blank == FB_BLANK_UNBLANK &&
            dev->props.power == FB_BLANK_UNBLANK) {
        if (md->has_bc)
            return acx565akm_get_actual_brightness(md);
        else
            return dev->props.brightness;
    }

    return 0;
}

static const struct backlight_ops acx565akm_bl_ops = {
    .get_brightness = acx565akm_bl_get_intensity,
    .update_status  = acx565akm_bl_update_status,
};

/*--------------------Auto Brightness control via Sysfs---------------------*/

static const char *cabc_modes[] = {
    "off",      /* always used when CABC is not supported */
    "ui",
    "still-image",
    "moving-image",
};

static ssize_t show_cabc_mode(struct device *dev,
        struct device_attribute *attr,
        char *buf)
{
    struct acx565akm_device *md = dev_get_drvdata(dev);
    const char *mode_str;
    int mode;
    int len;

    if (!md->has_cabc)
        mode = 0;
    else
        mode = get_cabc_mode(md);
    mode_str = "unknown";
    if (mode >= 0 && mode < ARRAY_SIZE(cabc_modes))
        mode_str = cabc_modes[mode];
    len = snprintf(buf, PAGE_SIZE, "%s\n", mode_str);

    return len < PAGE_SIZE - 1 ? len : PAGE_SIZE - 1;
}

static ssize_t store_cabc_mode(struct device *dev,
        struct device_attribute *attr,
        const char *buf, size_t count)
{
    struct acx565akm_device *md = dev_get_drvdata(dev);
    int i;

    for (i = 0; i < ARRAY_SIZE(cabc_modes); i++) {
        const char *mode_str = cabc_modes[i];
        int cmp_len = strlen(mode_str);

        if (count > 0 && buf[count - 1] == '\n')
            count--;
        if (count != cmp_len)
            continue;

        if (strncmp(buf, mode_str, cmp_len) == 0)
            break;
    }

    if (i == ARRAY_SIZE(cabc_modes))
        return -EINVAL;

    if (!md->has_cabc && i != 0)
        return -EINVAL;

    mutex_lock(&md->mutex);
    set_cabc_mode(md, i);
    mutex_unlock(&md->mutex);

    return count;
}

static ssize_t show_cabc_available_modes(struct device *dev,
        struct device_attribute *attr,
        char *buf)
{
    struct acx565akm_device *md = dev_get_drvdata(dev);
    int len;
    int i;

    if (!md->has_cabc)
        return snprintf(buf, PAGE_SIZE, "%s\n", cabc_modes[0]);

    for (i = 0, len = 0;
         len < PAGE_SIZE && i < ARRAY_SIZE(cabc_modes); i++)
        len += snprintf(&buf[len], PAGE_SIZE - len, "%s%s%s",
            i ? " " : "", cabc_modes[i],
            i == ARRAY_SIZE(cabc_modes) - 1 ? "\n" : "");

    return len < PAGE_SIZE ? len : PAGE_SIZE - 1;
}

static DEVICE_ATTR(cabc_mode, S_IRUGO | S_IWUSR,
        show_cabc_mode, store_cabc_mode);
static DEVICE_ATTR(cabc_available_modes, S_IRUGO,
        show_cabc_available_modes, NULL);

static struct attribute *bldev_attrs[] = {
    &dev_attr_cabc_mode.attr,
    &dev_attr_cabc_available_modes.attr,
    NULL,
};

static struct attribute_group bldev_attr_group = {
    .attrs = bldev_attrs,
};


/*---------------------------ACX Panel----------------------------*/

static int acx_get_recommended_bpp(struct omap_dss_device *dssdev)
{
    return 16;
}

static struct omap_video_timings acx_panel_timings = {
    .x_res      = 800,
    .y_res      = 480,
    .pixel_clock    = 24000,
    .hfp        = 28,
    .hsw        = 4,
    .hbp        = 24,
    .vfp        = 3,
    .vsw        = 3,
    .vbp        = 4,

    .vsync_level    = OMAPDSS_SIG_ACTIVE_LOW,
    .hsync_level    = OMAPDSS_SIG_ACTIVE_LOW,

    .data_pclk_edge = OMAPDSS_DRIVE_SIG_RISING_EDGE,
    .de_level   = OMAPDSS_SIG_ACTIVE_HIGH,
    .sync_pclk_edge = OMAPDSS_DRIVE_SIG_OPPOSITE_EDGES,
};

static int acx_panel_probe(struct omap_dss_device *dssdev)
{
    int r;
    struct acx565akm_device *md = &acx_dev;
    struct backlight_device *bldev;
    int max_brightness, brightness;
    struct backlight_properties props;

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

    /* FIXME AC bias ? */
    dssdev->panel.timings = acx_panel_timings;

    if (dssdev->platform_enable)
        dssdev->platform_enable(dssdev);
    /*
     * After reset we have to wait 5 msec before the first
     * command can be sent.
     */
    msleep(5);

    md->enabled = panel_enabled(md);

    r = panel_detect(md);
    if (r) {
        dev_err(&dssdev->dev, "%s panel detect error\n", __func__);
        if (!md->enabled && dssdev->platform_disable)
            dssdev->platform_disable(dssdev);
        return r;
    }

    mutex_lock(&acx_dev.mutex);
    acx_dev.dssdev = dssdev;
    mutex_unlock(&acx_dev.mutex);

    if (!md->enabled) {
        if (dssdev->platform_disable)
            dssdev->platform_disable(dssdev);
    }

    /*------- Backlight control --------*/

    memset(&props, 0, sizeof(props));
    props.fb_blank = FB_BLANK_UNBLANK;
    props.power = FB_BLANK_UNBLANK;
    props.type = BACKLIGHT_RAW;

    bldev = backlight_device_register("acx565akm", &md->spi->dev,
            md, &acx565akm_bl_ops, &props);
    md->bl_dev = bldev;
    if (md->has_cabc) {
        r = sysfs_create_group(&bldev->dev.kobj, &bldev_attr_group);
        if (r) {
            dev_err(&bldev->dev,
                "%s failed to create sysfs files\n", __func__);
            backlight_device_unregister(bldev);
            return r;
        }
        md->cabc_mode = get_hw_cabc_mode(md);
    }

    if (md->has_bc)
        max_brightness = 255;
    else
        max_brightness = dssdev->max_backlight_level;

    if (md->has_bc)
        brightness = acx565akm_get_actual_brightness(md);
    else if (dssdev->get_backlight)
        brightness = dssdev->get_backlight(dssdev);
    else
        brightness = 0;

    bldev->props.max_brightness = max_brightness;
    bldev->props.brightness = brightness;

    acx565akm_bl_update_status(bldev);
    return 0;
}

static void acx_panel_remove(struct omap_dss_device *dssdev)
{
    struct acx565akm_device *md = &acx_dev;

    dev_dbg(&dssdev->dev, "%s\n", __func__);
    sysfs_remove_group(&md->bl_dev->dev.kobj, &bldev_attr_group);
    backlight_device_unregister(md->bl_dev);
    mutex_lock(&acx_dev.mutex);
    acx_dev.dssdev = NULL;
    mutex_unlock(&acx_dev.mutex);
}

static int acx_panel_power_on(struct omap_dss_device *dssdev)
{
    struct acx565akm_device *md = &acx_dev;
    int r;

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

    if (dssdev->state == OMAP_DSS_DISPLAY_ACTIVE)
        return 0;

    mutex_lock(&md->mutex);

    omapdss_sdi_set_timings(dssdev, &dssdev->panel.timings);
    omapdss_sdi_set_datapairs(dssdev, dssdev->phy.sdi.datapairs);

    r = omapdss_sdi_display_enable(dssdev);
    if (r) {
        pr_err("%s sdi enable failed\n", __func__);
        goto fail_unlock;
    }

    /*FIXME tweak me */
    msleep(50);

    if (dssdev->platform_enable) {
        r = dssdev->platform_enable(dssdev);
        if (r)
            goto fail;
    }

    if (md->enabled) {
        dev_dbg(&md->spi->dev, "panel already enabled\n");
        mutex_unlock(&md->mutex);
        return 0;
    }

    /*
     * We have to meet all the following delay requirements:
     * 1. tRW: reset pulse width 10usec (7.12.1)
     * 2. tRT: reset cancel time 5msec (7.12.1)
     * 3. Providing PCLK,HS,VS signals for 2 frames = ~50msec worst
     *    case (7.6.2)
     * 4. 120msec before the sleep out command (7.12.1)
     */
    msleep(120);

    set_sleep_mode(md, 0);
    md->enabled = 1;

    /* 5msec between sleep out and the next command. (8.2.16) */
    msleep(5);
    set_display_state(md, 1);
    set_cabc_mode(md, md->cabc_mode);

    mutex_unlock(&md->mutex);

    return acx565akm_bl_update_status(md->bl_dev);
fail:
    omapdss_sdi_display_disable(dssdev);
fail_unlock:
    mutex_unlock(&md->mutex);
    return r;
}

static void acx_panel_power_off(struct omap_dss_device *dssdev)
{
    struct acx565akm_device *md = &acx_dev;

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

    if (dssdev->state != OMAP_DSS_DISPLAY_ACTIVE)
        return;

    mutex_lock(&md->mutex);

    if (!md->enabled) {
        mutex_unlock(&md->mutex);
        return;
    }
    set_display_state(md, 0);
    set_sleep_mode(md, 1);
    md->enabled = 0;
    /*
     * We have to provide PCLK,HS,VS signals for 2 frames (worst case
     * ~50msec) after sending the sleep in command and asserting the
     * reset signal. We probably could assert the reset w/o the delay
     * but we still delay to avoid possible artifacts. (7.6.1)
     */
    msleep(50);

    if (dssdev->platform_disable)
        dssdev->platform_disable(dssdev);

    /* FIXME need to tweak this delay */
    msleep(100);

    omapdss_sdi_display_disable(dssdev);

    mutex_unlock(&md->mutex);
}

static int acx_panel_enable(struct omap_dss_device *dssdev)
{
    int r;

    dev_dbg(&dssdev->dev, "%s\n", __func__);
    r = acx_panel_power_on(dssdev);

    if (r)
        return r;

    dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
    return 0;
}

static void acx_panel_disable(struct omap_dss_device *dssdev)
{
    dev_dbg(&dssdev->dev, "%s\n", __func__);
    acx_panel_power_off(dssdev);
    dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
}

static int acx_panel_suspend(struct omap_dss_device *dssdev)
{
    dev_dbg(&dssdev->dev, "%s\n", __func__);
    acx_panel_power_off(dssdev);
    dssdev->state = OMAP_DSS_DISPLAY_SUSPENDED;
    return 0;
}

static int acx_panel_resume(struct omap_dss_device *dssdev)
{
    int r;

    dev_dbg(&dssdev->dev, "%s\n", __func__);
    r = acx_panel_power_on(dssdev);
    if (r)
        return r;

    dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
    return 0;
}

static void acx_panel_set_timings(struct omap_dss_device *dssdev,
        struct omap_video_timings *timings)
{
    omapdss_sdi_set_timings(dssdev, timings);

    dssdev->panel.timings = *timings;
}

static int acx_panel_check_timings(struct omap_dss_device *dssdev,
        struct omap_video_timings *timings)
{
    return 0;
}


static struct omap_dss_driver acx_panel_driver = {
    .probe      = acx_panel_probe,
    .remove     = acx_panel_remove,

    .enable     = acx_panel_enable,
    .disable    = acx_panel_disable,
    .suspend    = acx_panel_suspend,
    .resume     = acx_panel_resume,

    .set_timings    = acx_panel_set_timings,
    .check_timings  = acx_panel_check_timings,

    .get_recommended_bpp = acx_get_recommended_bpp,

    .driver         = {
        .name   = "panel-acx565akm",
        .owner  = THIS_MODULE,
    },
};

/*--------------------SPI probe-------------------------*/

static int acx565akm_spi_probe(struct spi_device *spi)
{
    struct acx565akm_device *md = &acx_dev;

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

    spi->mode = SPI_MODE_3;
    md->spi = spi;
    mutex_init(&md->mutex);
    dev_set_drvdata(&spi->dev, md);

    omap_dss_register_driver(&acx_panel_driver);

    return 0;
}

static int acx565akm_spi_remove(struct spi_device *spi)
{
    struct acx565akm_device *md = dev_get_drvdata(&spi->dev);

    dev_dbg(&md->spi->dev, "%s\n", __func__);
    omap_dss_unregister_driver(&acx_panel_driver);

    return 0;
}

static struct spi_driver acx565akm_spi_driver = {
    .driver = {
        .name   = "acx565akm",
        .owner  = THIS_MODULE,
    },
    .probe  = acx565akm_spi_probe,
    .remove = __devexit_p(acx565akm_spi_remove),
};

module_spi_driver(acx565akm_spi_driver);

MODULE_AUTHOR("Nokia Corporation");
MODULE_DESCRIPTION("acx565akm LCD Driver");
MODULE_LICENSE("GPL");