/*
 * Analog Devices AD9389B/AD9889B video encoder driver
 *
 * Copyright 2012 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 *
 * This program is free software; you may redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/*
 * References (c = chapter, p = page):
 * REF_01 - Analog Devices, Programming Guide, AD9889B/AD9389B,
 * HDMI Transitter, Rev. A, October 2010
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/videodev2.h>
#include <linux/workqueue.h>
#include <linux/v4l2-dv-timings.h>
#include <media/v4l2-device.h>
#include <media/v4l2-common.h>
#include <media/v4l2-dv-timings.h>
#include <media/v4l2-ctrls.h>
#include <media/ad9389b.h>

static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "debug level (0-2)");

MODULE_DESCRIPTION("Analog Devices AD9389B/AD9889B video encoder driver");
MODULE_AUTHOR("Hans Verkuil <hans.verkuil@cisco.com>");
MODULE_AUTHOR("Martin Bugge <marbugge@cisco.com>");
MODULE_LICENSE("GPL");

#define MASK_AD9389B_EDID_RDY_INT   0x04
#define MASK_AD9389B_MSEN_INT       0x40
#define MASK_AD9389B_HPD_INT        0x80

#define MASK_AD9389B_HPD_DETECT     0x40
#define MASK_AD9389B_MSEN_DETECT    0x20
#define MASK_AD9389B_EDID_RDY       0x10

#define EDID_MAX_RETRIES (8)
#define EDID_DELAY 250
#define EDID_MAX_SEGM 8

/*
**********************************************************************
*
*  Arrays with configuration parameters for the AD9389B
*
**********************************************************************
*/

struct ad9389b_state_edid {
        /* total number of blocks */
        u32 blocks;
        /* Number of segments read */
        u32 segments;
        u8 data[EDID_MAX_SEGM * 256];
        /* Number of EDID read retries left */
        unsigned read_retries;
};

struct ad9389b_state {
        struct ad9389b_platform_data pdata;
        struct v4l2_subdev sd;
        struct media_pad pad;
        struct v4l2_ctrl_handler hdl;
        int chip_revision;
        /* Is the ad9389b powered on? */
        bool power_on;
        /* Did we receive hotplug and rx-sense signals? */
        bool have_monitor;
        /* timings from s_dv_timings */
        struct v4l2_dv_timings dv_timings;
        /* controls */
        struct v4l2_ctrl *hdmi_mode_ctrl;
        struct v4l2_ctrl *hotplug_ctrl;
        struct v4l2_ctrl *rx_sense_ctrl;
        struct v4l2_ctrl *have_edid0_ctrl;
        struct v4l2_ctrl *rgb_quantization_range_ctrl;
        struct i2c_client *edid_i2c_client;
        struct ad9389b_state_edid edid;
        /* Running counter of the number of detected EDIDs (for debugging) */
        unsigned edid_detect_counter;
        struct workqueue_struct *work_queue;
        struct delayed_work edid_handler; /* work entry */
};

static void ad9389b_check_monitor_present_status(struct v4l2_subdev *sd);
static bool ad9389b_check_edid_status(struct v4l2_subdev *sd);
static void ad9389b_setup(struct v4l2_subdev *sd);
static int ad9389b_s_i2s_clock_freq(struct v4l2_subdev *sd, u32 freq);
static int ad9389b_s_clock_freq(struct v4l2_subdev *sd, u32 freq);

static inline struct ad9389b_state *get_ad9389b_state(struct v4l2_subdev *sd)
{
        return container_of(sd, struct ad9389b_state, sd);
}

static inline struct v4l2_subdev *to_sd(struct v4l2_ctrl *ctrl)
{
        return &container_of(ctrl->handler, struct ad9389b_state, hdl)->sd;
}

/* ------------------------ I2C ----------------------------------------------- */

static int ad9389b_rd(struct v4l2_subdev *sd, u8 reg)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);

        return i2c_smbus_read_byte_data(client, reg);
}

static int ad9389b_wr(struct v4l2_subdev *sd, u8 reg, u8 val)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int ret;
        int i;

        for (i = 0; i < 3; i++) {
                ret = i2c_smbus_write_byte_data(client, reg, val);
                if (ret == 0)
                        return 0;
        }
        v4l2_err(sd, "%s: failed reg 0x%x, val 0x%x\n", __func__, reg, val);
        return ret;
}

/* To set specific bits in the register, a clear-mask is given (to be AND-ed),
   and then the value-mask (to be OR-ed). */
static inline void ad9389b_wr_and_or(struct v4l2_subdev *sd, u8 reg,
                                     u8 clr_mask, u8 val_mask)
{
        ad9389b_wr(sd, reg, (ad9389b_rd(sd, reg) & clr_mask) | val_mask);
}

static void ad9389b_edid_rd(struct v4l2_subdev *sd, u16 len, u8 *buf)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);
        int i;

        v4l2_dbg(1, debug, sd, "%s:\n", __func__);

        for (i = 0; i < len; i++)
                buf[i] = i2c_smbus_read_byte_data(state->edid_i2c_client, i);
}

static inline bool ad9389b_have_hotplug(struct v4l2_subdev *sd)
{
        return ad9389b_rd(sd, 0x42) & MASK_AD9389B_HPD_DETECT;
}

static inline bool ad9389b_have_rx_sense(struct v4l2_subdev *sd)
{
        return ad9389b_rd(sd, 0x42) & MASK_AD9389B_MSEN_DETECT;
}

static void ad9389b_csc_conversion_mode(struct v4l2_subdev *sd, u8 mode)
{
        ad9389b_wr_and_or(sd, 0x17, 0xe7, (mode & 0x3)<<3);
        ad9389b_wr_and_or(sd, 0x18, 0x9f, (mode & 0x3)<<5);
}

static void ad9389b_csc_coeff(struct v4l2_subdev *sd,
                              u16 A1, u16 A2, u16 A3, u16 A4,
                              u16 B1, u16 B2, u16 B3, u16 B4,
                              u16 C1, u16 C2, u16 C3, u16 C4)
{
        /* A */
        ad9389b_wr_and_or(sd, 0x18, 0xe0, A1>>8);
        ad9389b_wr(sd, 0x19, A1);
        ad9389b_wr_and_or(sd, 0x1A, 0xe0, A2>>8);
        ad9389b_wr(sd, 0x1B, A2);
        ad9389b_wr_and_or(sd, 0x1c, 0xe0, A3>>8);
        ad9389b_wr(sd, 0x1d, A3);
        ad9389b_wr_and_or(sd, 0x1e, 0xe0, A4>>8);
        ad9389b_wr(sd, 0x1f, A4);

        /* B */
        ad9389b_wr_and_or(sd, 0x20, 0xe0, B1>>8);
        ad9389b_wr(sd, 0x21, B1);
        ad9389b_wr_and_or(sd, 0x22, 0xe0, B2>>8);
        ad9389b_wr(sd, 0x23, B2);
        ad9389b_wr_and_or(sd, 0x24, 0xe0, B3>>8);
        ad9389b_wr(sd, 0x25, B3);
        ad9389b_wr_and_or(sd, 0x26, 0xe0, B4>>8);
        ad9389b_wr(sd, 0x27, B4);

        /* C */
        ad9389b_wr_and_or(sd, 0x28, 0xe0, C1>>8);
        ad9389b_wr(sd, 0x29, C1);
        ad9389b_wr_and_or(sd, 0x2A, 0xe0, C2>>8);
        ad9389b_wr(sd, 0x2B, C2);
        ad9389b_wr_and_or(sd, 0x2C, 0xe0, C3>>8);
        ad9389b_wr(sd, 0x2D, C3);
        ad9389b_wr_and_or(sd, 0x2E, 0xe0, C4>>8);
        ad9389b_wr(sd, 0x2F, C4);
}

static void ad9389b_csc_rgb_full2limit(struct v4l2_subdev *sd, bool enable)
{
        if (enable) {
                u8 csc_mode = 0;

                ad9389b_csc_conversion_mode(sd, csc_mode);
                ad9389b_csc_coeff(sd,
                                  4096-564, 0, 0, 256,
                                  0, 4096-564, 0, 256,
                                  0, 0, 4096-564, 256);
                /* enable CSC */
                ad9389b_wr_and_or(sd, 0x3b, 0xfe, 0x1);
                /* AVI infoframe: Limited range RGB (16-235) */
                ad9389b_wr_and_or(sd, 0xcd, 0xf9, 0x02);
        } else {
                /* disable CSC */
                ad9389b_wr_and_or(sd, 0x3b, 0xfe, 0x0);
                /* AVI infoframe: Full range RGB (0-255) */
                ad9389b_wr_and_or(sd, 0xcd, 0xf9, 0x04);
        }
}

static void ad9389b_set_IT_content_AVI_InfoFrame(struct v4l2_subdev *sd)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);

        if (state->dv_timings.bt.flags & V4L2_DV_FL_IS_CE_VIDEO) {
                /* CE format, not IT  */
                ad9389b_wr_and_or(sd, 0xcd, 0xbf, 0x00);
        } else {
                /* IT format */
                ad9389b_wr_and_or(sd, 0xcd, 0xbf, 0x40);
        }
}

static int ad9389b_set_rgb_quantization_mode(struct v4l2_subdev *sd, struct v4l2_ctrl *ctrl)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);

        switch (ctrl->val) {
        case V4L2_DV_RGB_RANGE_AUTO:
                /* automatic */
                if (state->dv_timings.bt.flags & V4L2_DV_FL_IS_CE_VIDEO) {
                        /* CE format, RGB limited range (16-235) */
                        ad9389b_csc_rgb_full2limit(sd, true);
                } else {
                        /* not CE format, RGB full range (0-255) */
                        ad9389b_csc_rgb_full2limit(sd, false);
                }
                break;
        case V4L2_DV_RGB_RANGE_LIMITED:
                /* RGB limited range (16-235) */
                ad9389b_csc_rgb_full2limit(sd, true);
                break;
        case V4L2_DV_RGB_RANGE_FULL:
                /* RGB full range (0-255) */
                ad9389b_csc_rgb_full2limit(sd, false);
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static void ad9389b_set_manual_pll_gear(struct v4l2_subdev *sd, u32 pixelclock)
{
        u8 gear;

        /* Workaround for TMDS PLL problem
         * The TMDS PLL in AD9389b change gear when the chip is heated above a
         * certain temperature. The output is disabled when the PLL change gear
         * so the monitor has to lock on the signal again. A workaround for
         * this is to use the manual PLL gears. This is a solution from Analog
         * Devices that is not documented in the datasheets.
         * 0x98 [7] = enable manual gearing. 0x98 [6:4] = gear
         *
         * The pixel frequency ranges are based on readout of the gear the
         * automatic gearing selects for different pixel clocks
         * (read from 0x9e [3:1]).
         */

        if (pixelclock > 140000000)
                gear = 0xc0; /* 4th gear */
        else if (pixelclock > 117000000)
                gear = 0xb0; /* 3rd gear */
        else if (pixelclock > 87000000)
                gear = 0xa0; /* 2nd gear */
        else if (pixelclock > 60000000)
                gear = 0x90; /* 1st gear */
        else
                gear = 0x80; /* 0th gear */

        ad9389b_wr_and_or(sd, 0x98, 0x0f, gear);
}

/* ------------------------------ CTRL OPS ------------------------------ */

static int ad9389b_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct v4l2_subdev *sd = to_sd(ctrl);
        struct ad9389b_state *state = get_ad9389b_state(sd);

        v4l2_dbg(1, debug, sd,
                 "%s: ctrl id: %d, ctrl->val %d\n", __func__, ctrl->id, ctrl->val);

        if (state->hdmi_mode_ctrl == ctrl) {
                /* Set HDMI or DVI-D */
                ad9389b_wr_and_or(sd, 0xaf, 0xfd,
                                  ctrl->val == V4L2_DV_TX_MODE_HDMI ? 0x02 : 0x00);
                return 0;
        }
        if (state->rgb_quantization_range_ctrl == ctrl)
                return ad9389b_set_rgb_quantization_mode(sd, ctrl);
        return -EINVAL;
}

static const struct v4l2_ctrl_ops ad9389b_ctrl_ops = {
        .s_ctrl = ad9389b_s_ctrl,
};

/* ---------------------------- CORE OPS ------------------------------------------- */

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int ad9389b_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
{
        reg->val = ad9389b_rd(sd, reg->reg & 0xff);
        reg->size = 1;
        return 0;
}

static int ad9389b_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
{
        ad9389b_wr(sd, reg->reg & 0xff, reg->val & 0xff);
        return 0;
}
#endif

static int ad9389b_log_status(struct v4l2_subdev *sd)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);
        struct ad9389b_state_edid *edid = &state->edid;

        static const char * const states[] = {
                "in reset",
                "reading EDID",
                "idle",
                "initializing HDCP",
                "HDCP enabled",
                "initializing HDCP repeater",
                "6", "7", "8", "9", "A", "B", "C", "D", "E", "F"
        };
        static const char * const errors[] = {
                "no error",
                "bad receiver BKSV",
                "Ri mismatch",
                "Pj mismatch",
                "i2c error",
                "timed out",
                "max repeater cascade exceeded",
                "hash check failed",
                "too many devices",
                "9", "A", "B", "C", "D", "E", "F"
        };

        u8 manual_gear;

        v4l2_info(sd, "chip revision %d\n", state->chip_revision);
        v4l2_info(sd, "power %s\n", state->power_on ? "on" : "off");
        v4l2_info(sd, "%s hotplug, %s Rx Sense, %s EDID (%d block(s))\n",
                  (ad9389b_rd(sd, 0x42) & MASK_AD9389B_HPD_DETECT) ?
                  "detected" : "no",
                  (ad9389b_rd(sd, 0x42) & MASK_AD9389B_MSEN_DETECT) ?
                  "detected" : "no",
                  edid->segments ? "found" : "no", edid->blocks);
        v4l2_info(sd, "%s output %s\n",
                  (ad9389b_rd(sd, 0xaf) & 0x02) ?
                  "HDMI" : "DVI-D",
                  (ad9389b_rd(sd, 0xa1) & 0x3c) ?
                  "disabled" : "enabled");
        v4l2_info(sd, "ad9389b: %s\n", (ad9389b_rd(sd, 0xb8) & 0x40) ?
                  "encrypted" : "no encryption");
        v4l2_info(sd, "state: %s, error: %s, detect count: %u, msk/irq: %02x/%02x\n",
                  states[ad9389b_rd(sd, 0xc8) & 0xf],
                  errors[ad9389b_rd(sd, 0xc8) >> 4],
                  state->edid_detect_counter,
                  ad9389b_rd(sd, 0x94), ad9389b_rd(sd, 0x96));
        manual_gear = ad9389b_rd(sd, 0x98) & 0x80;
        v4l2_info(sd, "ad9389b: RGB quantization: %s range\n",
                  ad9389b_rd(sd, 0x3b) & 0x01 ? "limited" : "full");
        v4l2_info(sd, "ad9389b: %s gear %d\n",
                  manual_gear ? "manual" : "automatic",
                  manual_gear ? ((ad9389b_rd(sd, 0x98) & 0x70) >> 4) :
                  ((ad9389b_rd(sd, 0x9e) & 0x0e) >> 1));
        if (ad9389b_rd(sd, 0xaf) & 0x02) {
                /* HDMI only */
                u8 manual_cts = ad9389b_rd(sd, 0x0a) & 0x80;
                u32 N = (ad9389b_rd(sd, 0x01) & 0xf) << 16 |
                        ad9389b_rd(sd, 0x02) << 8 |
                        ad9389b_rd(sd, 0x03);
                u8 vic_detect = ad9389b_rd(sd, 0x3e) >> 2;
                u8 vic_sent = ad9389b_rd(sd, 0x3d) & 0x3f;
                u32 CTS;

                if (manual_cts)
                        CTS = (ad9389b_rd(sd, 0x07) & 0xf) << 16 |
                              ad9389b_rd(sd, 0x08) << 8 |
                              ad9389b_rd(sd, 0x09);
                else
                        CTS = (ad9389b_rd(sd, 0x04) & 0xf) << 16 |
                              ad9389b_rd(sd, 0x05) << 8 |
                              ad9389b_rd(sd, 0x06);
                N = (ad9389b_rd(sd, 0x01) & 0xf) << 16 |
                    ad9389b_rd(sd, 0x02) << 8 |
                    ad9389b_rd(sd, 0x03);

                v4l2_info(sd, "ad9389b: CTS %s mode: N %d, CTS %d\n",
                          manual_cts ? "manual" : "automatic", N, CTS);

                v4l2_info(sd, "ad9389b: VIC: detected %d, sent %d\n",
                          vic_detect, vic_sent);
        }
        if (state->dv_timings.type == V4L2_DV_BT_656_1120)
                v4l2_print_dv_timings(sd->name, "timings: ",
                                &state->dv_timings, false);
        else
                v4l2_info(sd, "no timings set\n");
        return 0;
}

/* Power up/down ad9389b */
static int ad9389b_s_power(struct v4l2_subdev *sd, int on)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);
        struct ad9389b_platform_data *pdata = &state->pdata;
        const int retries = 20;
        int i;

        v4l2_dbg(1, debug, sd, "%s: power %s\n", __func__, on ? "on" : "off");

        state->power_on = on;

        if (!on) {
                /* Power down */
                ad9389b_wr_and_or(sd, 0x41, 0xbf, 0x40);
                return true;
        }

        /* Power up */
        /* The ad9389b does not always come up immediately.
           Retry multiple times. */
        for (i = 0; i < retries; i++) {
                ad9389b_wr_and_or(sd, 0x41, 0xbf, 0x0);
                if ((ad9389b_rd(sd, 0x41) & 0x40) == 0)
                        break;
                ad9389b_wr_and_or(sd, 0x41, 0xbf, 0x40);
                msleep(10);
        }
        if (i == retries) {
                v4l2_dbg(1, debug, sd, "failed to powerup the ad9389b\n");
                ad9389b_s_power(sd, 0);
                return false;
        }
        if (i > 1)
                v4l2_dbg(1, debug, sd,
                         "needed %d retries to powerup the ad9389b\n", i);

        /* Select chip: AD9389B */
        ad9389b_wr_and_or(sd, 0xba, 0xef, 0x10);

        /* Reserved registers that must be set according to REF_01 p. 11*/
        ad9389b_wr_and_or(sd, 0x98, 0xf0, 0x07);
        ad9389b_wr(sd, 0x9c, 0x38);
        ad9389b_wr_and_or(sd, 0x9d, 0xfc, 0x01);

        /* Differential output drive strength */
        if (pdata->diff_data_drive_strength > 0)
                ad9389b_wr(sd, 0xa2, pdata->diff_data_drive_strength);
        else
                ad9389b_wr(sd, 0xa2, 0x87);

        if (pdata->diff_clk_drive_strength > 0)
                ad9389b_wr(sd, 0xa3, pdata->diff_clk_drive_strength);
        else
                ad9389b_wr(sd, 0xa3, 0x87);

        ad9389b_wr(sd, 0x0a, 0x01);
        ad9389b_wr(sd, 0xbb, 0xff);

        /* Set number of attempts to read the EDID */
        ad9389b_wr(sd, 0xc9, 0xf);
        return true;
}

/* Enable interrupts */
static void ad9389b_set_isr(struct v4l2_subdev *sd, bool enable)
{
        u8 irqs = MASK_AD9389B_HPD_INT | MASK_AD9389B_MSEN_INT;
        u8 irqs_rd;
        int retries = 100;

        /* The datasheet says that the EDID ready interrupt should be
           disabled if there is no hotplug. */
        if (!enable)
                irqs = 0;
        else if (ad9389b_have_hotplug(sd))
                irqs |= MASK_AD9389B_EDID_RDY_INT;

        /*
         * This i2c write can fail (approx. 1 in 1000 writes). But it
         * is essential that this register is correct, so retry it
         * multiple times.
         *
         * Note that the i2c write does not report an error, but the readback
         * clearly shows the wrong value.
         */
        do {
                ad9389b_wr(sd, 0x94, irqs);
                irqs_rd = ad9389b_rd(sd, 0x94);
        } while (retries-- && irqs_rd != irqs);

        if (irqs_rd != irqs)
                v4l2_err(sd, "Could not set interrupts: hw failure?\n");
}

/* Interrupt handler */
static int ad9389b_isr(struct v4l2_subdev *sd, u32 status, bool *handled)
{
        u8 irq_status;

        /* disable interrupts to prevent a race condition */
        ad9389b_set_isr(sd, false);
        irq_status = ad9389b_rd(sd, 0x96);
        /* clear detected interrupts */
        ad9389b_wr(sd, 0x96, irq_status);
        /* enable interrupts */
        ad9389b_set_isr(sd, true);

        v4l2_dbg(1, debug, sd, "%s: irq_status 0x%x\n", __func__, irq_status);

        if (irq_status & (MASK_AD9389B_HPD_INT))
                ad9389b_check_monitor_present_status(sd);
        if (irq_status & MASK_AD9389B_EDID_RDY_INT)
                ad9389b_check_edid_status(sd);

        *handled = true;
        return 0;
}

static const struct v4l2_subdev_core_ops ad9389b_core_ops = {
        .log_status = ad9389b_log_status,
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .g_register = ad9389b_g_register,
        .s_register = ad9389b_s_register,
#endif
        .s_power = ad9389b_s_power,
        .interrupt_service_routine = ad9389b_isr,
};

/* ------------------------------ VIDEO OPS ------------------------------ */

/* Enable/disable ad9389b output */
static int ad9389b_s_stream(struct v4l2_subdev *sd, int enable)
{
        v4l2_dbg(1, debug, sd, "%s: %sable\n", __func__, (enable ? "en" : "dis"));

        ad9389b_wr_and_or(sd, 0xa1, ~0x3c, (enable ? 0 : 0x3c));
        if (enable) {
                ad9389b_check_monitor_present_status(sd);
        } else {
                ad9389b_s_power(sd, 0);
        }
        return 0;
}

static const struct v4l2_dv_timings_cap ad9389b_timings_cap = {
        .type = V4L2_DV_BT_656_1120,
        /* keep this initialization for compatibility with GCC < 4.4.6 */
        .reserved = { 0 },
        V4L2_INIT_BT_TIMINGS(0, 1920, 0, 1200, 25000000, 170000000,
                V4L2_DV_BT_STD_CEA861 | V4L2_DV_BT_STD_DMT |
                        V4L2_DV_BT_STD_GTF | V4L2_DV_BT_STD_CVT,
                V4L2_DV_BT_CAP_PROGRESSIVE | V4L2_DV_BT_CAP_REDUCED_BLANKING |
                V4L2_DV_BT_CAP_CUSTOM)
};

static int ad9389b_s_dv_timings(struct v4l2_subdev *sd,
                                struct v4l2_dv_timings *timings)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);

        v4l2_dbg(1, debug, sd, "%s:\n", __func__);

        /* quick sanity check */
        if (!v4l2_valid_dv_timings(timings, &ad9389b_timings_cap, NULL, NULL))
                return -EINVAL;

        /* Fill the optional fields .standards and .flags in struct v4l2_dv_timings
           if the format is one of the CEA or DMT timings. */
        v4l2_find_dv_timings_cap(timings, &ad9389b_timings_cap, 0, NULL, NULL);

        timings->bt.flags &= ~V4L2_DV_FL_REDUCED_FPS;

        /* save timings */
        state->dv_timings = *timings;

        /* update quantization range based on new dv_timings */
        ad9389b_set_rgb_quantization_mode(sd, state->rgb_quantization_range_ctrl);

        /* update PLL gear based on new dv_timings */
        if (state->pdata.tmds_pll_gear == AD9389B_TMDS_PLL_GEAR_SEMI_AUTOMATIC)
                ad9389b_set_manual_pll_gear(sd, (u32)timings->bt.pixelclock);

        /* update AVI infoframe */
        ad9389b_set_IT_content_AVI_InfoFrame(sd);

        return 0;
}

static int ad9389b_g_dv_timings(struct v4l2_subdev *sd,
                                struct v4l2_dv_timings *timings)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);

        v4l2_dbg(1, debug, sd, "%s:\n", __func__);

        if (!timings)
                return -EINVAL;

        *timings = state->dv_timings;

        return 0;
}

static int ad9389b_enum_dv_timings(struct v4l2_subdev *sd,
                                   struct v4l2_enum_dv_timings *timings)
{
        if (timings->pad != 0)
                return -EINVAL;

        return v4l2_enum_dv_timings_cap(timings, &ad9389b_timings_cap,
                        NULL, NULL);
}

static int ad9389b_dv_timings_cap(struct v4l2_subdev *sd,
                                  struct v4l2_dv_timings_cap *cap)
{
        if (cap->pad != 0)
                return -EINVAL;

        *cap = ad9389b_timings_cap;
        return 0;
}

static const struct v4l2_subdev_video_ops ad9389b_video_ops = {
        .s_stream = ad9389b_s_stream,
        .s_dv_timings = ad9389b_s_dv_timings,
        .g_dv_timings = ad9389b_g_dv_timings,
};

/* ------------------------------ PAD OPS ------------------------------ */

static int ad9389b_get_edid(struct v4l2_subdev *sd, struct v4l2_edid *edid)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);

        if (edid->pad != 0)
                return -EINVAL;
        if (edid->blocks == 0 || edid->blocks > 256)
                return -EINVAL;
        if (!state->edid.segments) {
                v4l2_dbg(1, debug, sd, "EDID segment 0 not found\n");
                return -ENODATA;
        }
        if (edid->start_block >= state->edid.segments * 2)
                return -E2BIG;
        if (edid->blocks + edid->start_block >= state->edid.segments * 2)
                edid->blocks = state->edid.segments * 2 - edid->start_block;
        memcpy(edid->edid, &state->edid.data[edid->start_block * 128],
               128 * edid->blocks);
        return 0;
}

static const struct v4l2_subdev_pad_ops ad9389b_pad_ops = {
        .get_edid = ad9389b_get_edid,
        .enum_dv_timings = ad9389b_enum_dv_timings,
        .dv_timings_cap = ad9389b_dv_timings_cap,
};

/* ------------------------------ AUDIO OPS ------------------------------ */

static int ad9389b_s_audio_stream(struct v4l2_subdev *sd, int enable)
{
        v4l2_dbg(1, debug, sd, "%s: %sable\n", __func__, (enable ? "en" : "dis"));

        if (enable)
                ad9389b_wr_and_or(sd, 0x45, 0x3f, 0x80);
        else
                ad9389b_wr_and_or(sd, 0x45, 0x3f, 0x40);

        return 0;
}

static int ad9389b_s_clock_freq(struct v4l2_subdev *sd, u32 freq)
{
        u32 N;

        switch (freq) {
        case 32000:  N = 4096;  break;
        case 44100:  N = 6272;  break;
        case 48000:  N = 6144;  break;
        case 88200:  N = 12544; break;
        case 96000:  N = 12288; break;
        case 176400: N = 25088; break;
        case 192000: N = 24576; break;
        default:
             return -EINVAL;
        }

        /* Set N (used with CTS to regenerate the audio clock) */
        ad9389b_wr(sd, 0x01, (N >> 16) & 0xf);
        ad9389b_wr(sd, 0x02, (N >> 8) & 0xff);
        ad9389b_wr(sd, 0x03, N & 0xff);

        return 0;
}

static int ad9389b_s_i2s_clock_freq(struct v4l2_subdev *sd, u32 freq)
{
        u32 i2s_sf;

        switch (freq) {
        case 32000:  i2s_sf = 0x30; break;
        case 44100:  i2s_sf = 0x00; break;
        case 48000:  i2s_sf = 0x20; break;
        case 88200:  i2s_sf = 0x80; break;
        case 96000:  i2s_sf = 0xa0; break;
        case 176400: i2s_sf = 0xc0; break;
        case 192000: i2s_sf = 0xe0; break;
        default:
             return -EINVAL;
        }

        /* Set sampling frequency for I2S audio to 48 kHz */
        ad9389b_wr_and_or(sd, 0x15, 0xf, i2s_sf);

        return 0;
}

static int ad9389b_s_routing(struct v4l2_subdev *sd, u32 input, u32 output, u32 config)
{
        /* TODO based on input/output/config */
        /* TODO See datasheet "Programmers guide" p. 39-40 */

        /* Only 2 channels in use for application */
        ad9389b_wr_and_or(sd, 0x50, 0x1f, 0x20);
        /* Speaker mapping */
        ad9389b_wr(sd, 0x51, 0x00);

        /* TODO Where should this be placed? */
        /* 16 bit audio word length */
        ad9389b_wr_and_or(sd, 0x14, 0xf0, 0x02);

        return 0;
}

static const struct v4l2_subdev_audio_ops ad9389b_audio_ops = {
        .s_stream = ad9389b_s_audio_stream,
        .s_clock_freq = ad9389b_s_clock_freq,
        .s_i2s_clock_freq = ad9389b_s_i2s_clock_freq,
        .s_routing = ad9389b_s_routing,
};

/* --------------------- SUBDEV OPS --------------------------------------- */

static const struct v4l2_subdev_ops ad9389b_ops = {
        .core  = &ad9389b_core_ops,
        .video = &ad9389b_video_ops,
        .audio = &ad9389b_audio_ops,
        .pad = &ad9389b_pad_ops,
};

/* ----------------------------------------------------------------------- */
static void ad9389b_dbg_dump_edid(int lvl, int debug, struct v4l2_subdev *sd,
                                  int segment, u8 *buf)
{
        int i, j;

        if (debug < lvl)
                return;

        v4l2_dbg(lvl, debug, sd, "edid segment %d\n", segment);
        for (i = 0; i < 256; i += 16) {
                u8 b[128];
                u8 *bp = b;

                if (i == 128)
                        v4l2_dbg(lvl, debug, sd, "\n");
                for (j = i; j < i + 16; j++) {
                        sprintf(bp, "0x%02x, ", buf[j]);
                        bp += 6;
                }
                bp[0] = '\0';
                v4l2_dbg(lvl, debug, sd, "%s\n", b);
        }
}

static void ad9389b_edid_handler(struct work_struct *work)
{
        struct delayed_work *dwork = to_delayed_work(work);
        struct ad9389b_state *state =
                container_of(dwork, struct ad9389b_state, edid_handler);
        struct v4l2_subdev *sd = &state->sd;
        struct ad9389b_edid_detect ed;

        v4l2_dbg(1, debug, sd, "%s:\n", __func__);

        if (ad9389b_check_edid_status(sd)) {
                /* Return if we received the EDID. */
                return;
        }

        if (ad9389b_have_hotplug(sd)) {
                /* We must retry reading the EDID several times, it is possible
                 * that initially the EDID couldn't be read due to i2c errors
                 * (DVI connectors are particularly prone to this problem). */
                if (state->edid.read_retries) {
                        state->edid.read_retries--;
                        v4l2_dbg(1, debug, sd, "%s: edid read failed\n", __func__);
                        ad9389b_s_power(sd, false);
                        ad9389b_s_power(sd, true);
                        queue_delayed_work(state->work_queue,
                                           &state->edid_handler, EDID_DELAY);
                        return;
                }
        }

        /* We failed to read the EDID, so send an event for this. */
        ed.present = false;
        ed.segment = ad9389b_rd(sd, 0xc4);
        v4l2_subdev_notify(sd, AD9389B_EDID_DETECT, (void *)&ed);
        v4l2_dbg(1, debug, sd, "%s: no edid found\n", __func__);
}

static void ad9389b_audio_setup(struct v4l2_subdev *sd)
{
        v4l2_dbg(1, debug, sd, "%s\n", __func__);

        ad9389b_s_i2s_clock_freq(sd, 48000);
        ad9389b_s_clock_freq(sd, 48000);
        ad9389b_s_routing(sd, 0, 0, 0);
}

/* Initial setup of AD9389b */

/* Configure hdmi transmitter. */
static void ad9389b_setup(struct v4l2_subdev *sd)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);

        v4l2_dbg(1, debug, sd, "%s\n", __func__);

        /* Input format: RGB 4:4:4 */
        ad9389b_wr_and_or(sd, 0x15, 0xf1, 0x0);
        /* Output format: RGB 4:4:4 */
        ad9389b_wr_and_or(sd, 0x16, 0x3f, 0x0);
        /* 1st order interpolation 4:2:2 -> 4:4:4 up conversion,
           Aspect ratio: 16:9 */
        ad9389b_wr_and_or(sd, 0x17, 0xf9, 0x06);
        /* Output format: RGB 4:4:4, Active Format Information is valid. */
        ad9389b_wr_and_or(sd, 0x45, 0xc7, 0x08);
        /* Underscanned */
        ad9389b_wr_and_or(sd, 0x46, 0x3f, 0x80);
        /* Setup video format */
        ad9389b_wr(sd, 0x3c, 0x0);
        /* Active format aspect ratio: same as picure. */
        ad9389b_wr(sd, 0x47, 0x80);
        /* No encryption */
        ad9389b_wr_and_or(sd, 0xaf, 0xef, 0x0);
        /* Positive clk edge capture for input video clock */
        ad9389b_wr_and_or(sd, 0xba, 0x1f, 0x60);

        ad9389b_audio_setup(sd);

        v4l2_ctrl_handler_setup(&state->hdl);

        ad9389b_set_IT_content_AVI_InfoFrame(sd);
}

static void ad9389b_notify_monitor_detect(struct v4l2_subdev *sd)
{
        struct ad9389b_monitor_detect mdt;
        struct ad9389b_state *state = get_ad9389b_state(sd);

        mdt.present = state->have_monitor;
        v4l2_subdev_notify(sd, AD9389B_MONITOR_DETECT, (void *)&mdt);
}

static void ad9389b_update_monitor_present_status(struct v4l2_subdev *sd)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);
        /* read hotplug and rx-sense state */
        u8 status = ad9389b_rd(sd, 0x42);

        v4l2_dbg(1, debug, sd, "%s: status: 0x%x%s%s\n",
                 __func__,
                 status,
                 status & MASK_AD9389B_HPD_DETECT ? ", hotplug" : "",
                 status & MASK_AD9389B_MSEN_DETECT ? ", rx-sense" : "");

        if (status & MASK_AD9389B_HPD_DETECT) {
                v4l2_dbg(1, debug, sd, "%s: hotplug detected\n", __func__);
                state->have_monitor = true;
                if (!ad9389b_s_power(sd, true)) {
                        v4l2_dbg(1, debug, sd,
                                 "%s: monitor detected, powerup failed\n", __func__);
                        return;
                }
                ad9389b_setup(sd);
                ad9389b_notify_monitor_detect(sd);
                state->edid.read_retries = EDID_MAX_RETRIES;
                queue_delayed_work(state->work_queue,
                                   &state->edid_handler, EDID_DELAY);
        } else if (!(status & MASK_AD9389B_HPD_DETECT)) {
                v4l2_dbg(1, debug, sd, "%s: hotplug not detected\n", __func__);
                state->have_monitor = false;
                ad9389b_notify_monitor_detect(sd);
                ad9389b_s_power(sd, false);
                memset(&state->edid, 0, sizeof(struct ad9389b_state_edid));
        }

        /* update read only ctrls */
        v4l2_ctrl_s_ctrl(state->hotplug_ctrl, ad9389b_have_hotplug(sd) ? 0x1 : 0x0);
        v4l2_ctrl_s_ctrl(state->rx_sense_ctrl, ad9389b_have_rx_sense(sd) ? 0x1 : 0x0);
        v4l2_ctrl_s_ctrl(state->have_edid0_ctrl, state->edid.segments ? 0x1 : 0x0);

        /* update with setting from ctrls */
        ad9389b_s_ctrl(state->rgb_quantization_range_ctrl);
        ad9389b_s_ctrl(state->hdmi_mode_ctrl);
}

static void ad9389b_check_monitor_present_status(struct v4l2_subdev *sd)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);
        int retry = 0;

        ad9389b_update_monitor_present_status(sd);

        /*
         * Rapid toggling of the hotplug may leave the chip powered off,
         * even if we think it is on. In that case reset and power up again.
         */
        while (state->power_on && (ad9389b_rd(sd, 0x41) & 0x40)) {
                if (++retry > 5) {
                        v4l2_err(sd, "retried %d times, give up\n", retry);
                        return;
                }
                v4l2_dbg(1, debug, sd, "%s: reset and re-check status (%d)\n", __func__, retry);
                ad9389b_notify_monitor_detect(sd);
                cancel_delayed_work_sync(&state->edid_handler);
                memset(&state->edid, 0, sizeof(struct ad9389b_state_edid));
                ad9389b_s_power(sd, false);
                ad9389b_update_monitor_present_status(sd);
        }
}

static bool edid_block_verify_crc(u8 *edid_block)
{
        u8 sum = 0;
        int i;

        for (i = 0; i < 128; i++)
                sum += edid_block[i];
        return sum == 0;
}

static bool edid_verify_crc(struct v4l2_subdev *sd, u32 segment)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);
        u32 blocks = state->edid.blocks;
        u8 *data = state->edid.data;

        if (edid_block_verify_crc(&data[segment * 256])) {
                if ((segment + 1) * 2 <= blocks)
                        return edid_block_verify_crc(&data[segment * 256 + 128]);
                return true;

        }
        return false;
}

static bool edid_verify_header(struct v4l2_subdev *sd, u32 segment)
{
        static const u8 hdmi_header[] = {
                0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
        };
        struct ad9389b_state *state = get_ad9389b_state(sd);
        u8 *data = state->edid.data;
        int i;

        if (segment)
                return true;

        for (i = 0; i < ARRAY_SIZE(hdmi_header); i++)
                if (data[i] != hdmi_header[i])
                        return false;

        return true;
}

static bool ad9389b_check_edid_status(struct v4l2_subdev *sd)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);
        struct ad9389b_edid_detect ed;
        int segment;
        u8 edidRdy = ad9389b_rd(sd, 0xc5);

        v4l2_dbg(1, debug, sd, "%s: edid ready (retries: %d)\n",
                 __func__, EDID_MAX_RETRIES - state->edid.read_retries);

        if (!(edidRdy & MASK_AD9389B_EDID_RDY))
                return false;

        segment = ad9389b_rd(sd, 0xc4);
        if (segment >= EDID_MAX_SEGM) {
                v4l2_err(sd, "edid segment number too big\n");
                return false;
        }
        v4l2_dbg(1, debug, sd, "%s: got segment %d\n", __func__, segment);
        ad9389b_edid_rd(sd, 256, &state->edid.data[segment * 256]);
        ad9389b_dbg_dump_edid(2, debug, sd, segment,
                              &state->edid.data[segment * 256]);
        if (segment == 0) {
                state->edid.blocks = state->edid.data[0x7e] + 1;
                v4l2_dbg(1, debug, sd, "%s: %d blocks in total\n",
                         __func__, state->edid.blocks);
        }
        if (!edid_verify_crc(sd, segment) ||
            !edid_verify_header(sd, segment)) {
                /* edid crc error, force reread of edid segment */
                v4l2_err(sd, "%s: edid crc or header error\n", __func__);
                ad9389b_s_power(sd, false);
                ad9389b_s_power(sd, true);
                return false;
        }
        /* one more segment read ok */
        state->edid.segments = segment + 1;
        if (((state->edid.data[0x7e] >> 1) + 1) > state->edid.segments) {
                /* Request next EDID segment */
                v4l2_dbg(1, debug, sd, "%s: request segment %d\n",
                         __func__, state->edid.segments);
                ad9389b_wr(sd, 0xc9, 0xf);
                ad9389b_wr(sd, 0xc4, state->edid.segments);
                state->edid.read_retries = EDID_MAX_RETRIES;
                queue_delayed_work(state->work_queue,
                                   &state->edid_handler, EDID_DELAY);
                return false;
        }

        /* report when we have all segments but report only for segment 0 */
        ed.present = true;
        ed.segment = 0;
        v4l2_subdev_notify(sd, AD9389B_EDID_DETECT, (void *)&ed);
        state->edid_detect_counter++;
        v4l2_ctrl_s_ctrl(state->have_edid0_ctrl, state->edid.segments ? 0x1 : 0x0);
        return ed.present;
}

/* ----------------------------------------------------------------------- */

static void ad9389b_init_setup(struct v4l2_subdev *sd)
{
        struct ad9389b_state *state = get_ad9389b_state(sd);
        struct ad9389b_state_edid *edid = &state->edid;

        v4l2_dbg(1, debug, sd, "%s\n", __func__);

        /* clear all interrupts */
        ad9389b_wr(sd, 0x96, 0xff);

        memset(edid, 0, sizeof(struct ad9389b_state_edid));
        state->have_monitor = false;
        ad9389b_set_isr(sd, false);
}

static int ad9389b_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
        const struct v4l2_dv_timings dv1080p60 = V4L2_DV_BT_CEA_1920X1080P60;
        struct ad9389b_state *state;
        struct ad9389b_platform_data *pdata = client->dev.platform_data;
        struct v4l2_ctrl_handler *hdl;
        struct v4l2_subdev *sd;
        int err = -EIO;

        /* Check if the adapter supports the needed features */
        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -EIO;

        v4l_dbg(1, debug, client, "detecting ad9389b client on address 0x%x\n",
                client->addr << 1);

        state = devm_kzalloc(&client->dev, sizeof(*state), GFP_KERNEL);
        if (!state)
                return -ENOMEM;

        /* Platform data */
        if (pdata == NULL) {
                v4l_err(client, "No platform data!\n");
                return -ENODEV;
        }
        memcpy(&state->pdata, pdata, sizeof(state->pdata));

        sd = &state->sd;
        v4l2_i2c_subdev_init(sd, client, &ad9389b_ops);
        sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;

        hdl = &state->hdl;
        v4l2_ctrl_handler_init(hdl, 5);

        /* private controls */

        state->hdmi_mode_ctrl = v4l2_ctrl_new_std_menu(hdl, &ad9389b_ctrl_ops,
                        V4L2_CID_DV_TX_MODE, V4L2_DV_TX_MODE_HDMI,
                        0, V4L2_DV_TX_MODE_DVI_D);
        state->hotplug_ctrl = v4l2_ctrl_new_std(hdl, NULL,
                        V4L2_CID_DV_TX_HOTPLUG, 0, 1, 0, 0);
        state->rx_sense_ctrl = v4l2_ctrl_new_std(hdl, NULL,
                        V4L2_CID_DV_TX_RXSENSE, 0, 1, 0, 0);
        state->have_edid0_ctrl = v4l2_ctrl_new_std(hdl, NULL,
                        V4L2_CID_DV_TX_EDID_PRESENT, 0, 1, 0, 0);
        state->rgb_quantization_range_ctrl =
                v4l2_ctrl_new_std_menu(hdl, &ad9389b_ctrl_ops,
                        V4L2_CID_DV_TX_RGB_RANGE, V4L2_DV_RGB_RANGE_FULL,
                        0, V4L2_DV_RGB_RANGE_AUTO);
        sd->ctrl_handler = hdl;
        if (hdl->error) {
                err = hdl->error;

                goto err_hdl;
        }
        state->hdmi_mode_ctrl->is_private = true;
        state->hotplug_ctrl->is_private = true;
        state->rx_sense_ctrl->is_private = true;
        state->have_edid0_ctrl->is_private = true;
        state->rgb_quantization_range_ctrl->is_private = true;

        state->pad.flags = MEDIA_PAD_FL_SINK;
        err = media_entity_init(&sd->entity, 1, &state->pad, 0);
        if (err)
                goto err_hdl;

        state->chip_revision = ad9389b_rd(sd, 0x0);
        if (state->chip_revision != 2) {
                v4l2_err(sd, "chip_revision %d != 2\n", state->chip_revision);
                err = -EIO;
                goto err_entity;
        }
        v4l2_dbg(1, debug, sd, "reg 0x41 0x%x, chip version (reg 0x00) 0x%x\n",
                 ad9389b_rd(sd, 0x41), state->chip_revision);

        state->edid_i2c_client = i2c_new_dummy(client->adapter, (0x7e>>1));
        if (state->edid_i2c_client == NULL) {
                v4l2_err(sd, "failed to register edid i2c client\n");
                err = -ENOMEM;
                goto err_entity;
        }

        state->work_queue = create_singlethread_workqueue(sd->name);
        if (state->work_queue == NULL) {
                v4l2_err(sd, "could not create workqueue\n");
                err = -ENOMEM;
                goto err_unreg;
        }

        INIT_DELAYED_WORK(&state->edid_handler, ad9389b_edid_handler);
        state->dv_timings = dv1080p60;

        ad9389b_init_setup(sd);
        ad9389b_set_isr(sd, true);

        v4l2_info(sd, "%s found @ 0x%x (%s)\n", client->name,
                  client->addr << 1, client->adapter->name);
        return 0;

err_unreg:
        i2c_unregister_device(state->edid_i2c_client);
err_entity:
        media_entity_cleanup(&sd->entity);
err_hdl:
        v4l2_ctrl_handler_free(&state->hdl);
        return err;
}

/* ----------------------------------------------------------------------- */

static int ad9389b_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct ad9389b_state *state = get_ad9389b_state(sd);

        state->chip_revision = -1;

        v4l2_dbg(1, debug, sd, "%s removed @ 0x%x (%s)\n", client->name,
                 client->addr << 1, client->adapter->name);

        ad9389b_s_stream(sd, false);
        ad9389b_s_audio_stream(sd, false);
        ad9389b_init_setup(sd);
        cancel_delayed_work(&state->edid_handler);
        i2c_unregister_device(state->edid_i2c_client);
        destroy_workqueue(state->work_queue);
        v4l2_device_unregister_subdev(sd);
        media_entity_cleanup(&sd->entity);
        v4l2_ctrl_handler_free(sd->ctrl_handler);
        return 0;
}

/* ----------------------------------------------------------------------- */

static struct i2c_device_id ad9389b_id[] = {
        { "ad9389b", 0 },
        { "ad9889b", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, ad9389b_id);

static struct i2c_driver ad9389b_driver = {
        .driver = {
                .owner = THIS_MODULE,
                .name = "ad9389b",
        },
        .probe = ad9389b_probe,
        .remove = ad9389b_remove,
        .id_table = ad9389b_id,
};

module_i2c_driver(ad9389b_driver);