/*
 * Support for ACX565AKM LCD Panel used on Nokia N900
 *
 * Copyright (C) 2010 Nokia Corporation
 *
 * Original Driver Author: Imre Deak <imre.deak@nokia.com>
 * Based on panel-generic.c by Tomi Valkeinen <tomi.valkeinen@nokia.com>
 * Adapted to new DSS2 framework: Roger Quadros <roger.quadros@nokia.com>
 *
 * 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 <linux/gpio.h>

#include <video/omapdss.h>
#include <video/omap-panel-data.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
                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)
                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 struct panel_acx565akm_data *get_panel_data(struct omap_dss_device *dssdev)
{
        return (struct panel_acx565akm_data *) dssdev->data;
}

static int acx_panel_probe(struct omap_dss_device *dssdev)
{
        int r;
        struct acx565akm_device *md = &acx_dev;
        struct panel_acx565akm_data *panel_data = get_panel_data(dssdev);
        struct backlight_device *bldev;
        int max_brightness, brightness;
        struct backlight_properties props;

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

        if (!panel_data)
                return -EINVAL;

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

        if (gpio_is_valid(panel_data->reset_gpio)) {
                r = devm_gpio_request_one(&dssdev->dev, panel_data->reset_gpio,
                                GPIOF_OUT_INIT_LOW, "lcd reset");
                if (r)
                        return r;
        }

        if (gpio_is_valid(panel_data->reset_gpio))
                gpio_set_value(panel_data->reset_gpio, 1);

        /*
         * 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 && gpio_is_valid(panel_data->reset_gpio))
                        gpio_set_value(panel_data->reset_gpio, 0);

                return r;
        }

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

        if (!md->enabled) {
                if (gpio_is_valid(panel_data->reset_gpio))
                        gpio_set_value(panel_data->reset_gpio, 0);
        }

        /*------- 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);
        }

        max_brightness = 255;

        if (md->has_bc)
                brightness = acx565akm_get_actual_brightness(md);
        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;
        struct panel_acx565akm_data *panel_data = get_panel_data(dssdev);
        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 (gpio_is_valid(panel_data->reset_gpio))
                gpio_set_value(panel_data->reset_gpio, 1);

        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_unlock:
        mutex_unlock(&md->mutex);
        return r;
}

static void acx_panel_power_off(struct omap_dss_device *dssdev)
{
        struct acx565akm_device *md = &acx_dev;
        struct panel_acx565akm_data *panel_data = get_panel_data(dssdev);

        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 (gpio_is_valid(panel_data->reset_gpio))
                gpio_set_value(panel_data->reset_gpio, 0);

        /* 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 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,

        .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 = acx565akm_spi_remove,
};

module_spi_driver(acx565akm_spi_driver);

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