/*
 * ths8200 - Texas Instruments THS8200 video encoder driver
 *
 * Copyright 2013 Cisco Systems, Inc. and/or its affiliates.
 *
 * 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.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 * This program is distributed .as is. WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/v4l2-dv-timings.h>

#include <media/v4l2-device.h>

#include "ths8200_regs.h"

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

MODULE_DESCRIPTION("Texas Instruments THS8200 video encoder driver");
MODULE_AUTHOR("Mats Randgaard <mats.randgaard@cisco.com>");
MODULE_AUTHOR("Martin Bugge <martin.bugge@cisco.com>");
MODULE_LICENSE("GPL v2");

struct ths8200_state {
        struct v4l2_subdev sd;
        uint8_t chip_version;
        /* Is the ths8200 powered on? */
        bool power_on;
        struct v4l2_dv_timings dv_timings;
};

static const struct v4l2_dv_timings ths8200_timings[] = {
        V4L2_DV_BT_CEA_720X480P59_94,
        V4L2_DV_BT_CEA_1280X720P24,
        V4L2_DV_BT_CEA_1280X720P25,
        V4L2_DV_BT_CEA_1280X720P30,
        V4L2_DV_BT_CEA_1280X720P50,
        V4L2_DV_BT_CEA_1280X720P60,
        V4L2_DV_BT_CEA_1920X1080P24,
        V4L2_DV_BT_CEA_1920X1080P25,
        V4L2_DV_BT_CEA_1920X1080P30,
        V4L2_DV_BT_CEA_1920X1080P50,
        V4L2_DV_BT_CEA_1920X1080P60,
};

static inline struct ths8200_state *to_state(struct v4l2_subdev *sd)
{
        return container_of(sd, struct ths8200_state, sd);
}

static inline unsigned hblanking(const struct v4l2_bt_timings *t)
{
        return t->hfrontporch + t->hsync + t->hbackporch;
}

static inline unsigned htotal(const struct v4l2_bt_timings *t)
{
        return t->width + t->hfrontporch + t->hsync + t->hbackporch;
}

static inline unsigned vblanking(const struct v4l2_bt_timings *t)
{
        return t->vfrontporch + t->vsync + t->vbackporch;
}

static inline unsigned vtotal(const struct v4l2_bt_timings *t)
{
        return t->height + t->vfrontporch + t->vsync + t->vbackporch;
}

static int ths8200_read(struct v4l2_subdev *sd, u8 reg)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);

        return i2c_smbus_read_byte_data(client, reg);
}

static int ths8200_write(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, "I2C Write Problem\n");
        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
ths8200_write_and_or(struct v4l2_subdev *sd, u8 reg,
                     uint8_t clr_mask, uint8_t val_mask)
{
        ths8200_write(sd, reg, (ths8200_read(sd, reg) & clr_mask) | val_mask);
}

#ifdef CONFIG_VIDEO_ADV_DEBUG

static int ths8200_g_register(struct v4l2_subdev *sd,
                              struct v4l2_dbg_register *reg)
{
        reg->val = ths8200_read(sd, reg->reg & 0xff);
        reg->size = 1;

        return 0;
}

static int ths8200_s_register(struct v4l2_subdev *sd,
                              const struct v4l2_dbg_register *reg)
{
        ths8200_write(sd, reg->reg & 0xff, reg->val & 0xff);

        return 0;
}
#endif

static void ths8200_print_timings(struct v4l2_subdev *sd,
                                  struct v4l2_dv_timings *timings,
                                  const char *txt, bool detailed)
{
        struct v4l2_bt_timings *bt = &timings->bt;
        u32 htot, vtot;

        if (timings->type != V4L2_DV_BT_656_1120)
                return;

        htot = htotal(bt);
        vtot = vtotal(bt);

        v4l2_info(sd, "%s %dx%d%s%d (%dx%d)",
                  txt, bt->width, bt->height, bt->interlaced ? "i" : "p",
                  (htot * vtot) > 0 ? ((u32)bt->pixelclock / (htot * vtot)) : 0,
                  htot, vtot);

        if (detailed) {
                v4l2_info(sd, "    horizontal: fp = %d, %ssync = %d, bp = %d\n",
                          bt->hfrontporch,
                          (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-",
                          bt->hsync, bt->hbackporch);
                v4l2_info(sd, "    vertical: fp = %d, %ssync = %d, bp = %d\n",
                          bt->vfrontporch,
                          (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
                          bt->vsync, bt->vbackporch);
                v4l2_info(sd,
                          "    pixelclock: %lld, flags: 0x%x, standards: 0x%x\n",
                          bt->pixelclock, bt->flags, bt->standards);
        }
}

static int ths8200_log_status(struct v4l2_subdev *sd)
{
        struct ths8200_state *state = to_state(sd);
        uint8_t reg_03 = ths8200_read(sd, THS8200_CHIP_CTL);

        v4l2_info(sd, "----- Chip status -----\n");
        v4l2_info(sd, "version: %u\n", state->chip_version);
        v4l2_info(sd, "power: %s\n", (reg_03 & 0x0c) ? "off" : "on");
        v4l2_info(sd, "reset: %s\n", (reg_03 & 0x01) ? "off" : "on");
        v4l2_info(sd, "test pattern: %s\n",
                  (reg_03 & 0x20) ? "enabled" : "disabled");
        v4l2_info(sd, "format: %ux%u\n",
                  ths8200_read(sd, THS8200_DTG2_PIXEL_CNT_MSB) * 256 +
                  ths8200_read(sd, THS8200_DTG2_PIXEL_CNT_LSB),
                  (ths8200_read(sd, THS8200_DTG2_LINE_CNT_MSB) & 0x07) * 256 +
                  ths8200_read(sd, THS8200_DTG2_LINE_CNT_LSB));
        ths8200_print_timings(sd, &state->dv_timings,
                              "Configured format:", true);

        return 0;
}

/* Power up/down ths8200 */
static int ths8200_s_power(struct v4l2_subdev *sd, int on)
{
        struct ths8200_state *state = to_state(sd);

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

        state->power_on = on;

        /* Power up/down - leave in reset state until input video is present */
        ths8200_write_and_or(sd, THS8200_CHIP_CTL, 0xf2, (on ? 0x00 : 0x0c));

        return 0;
}

static const struct v4l2_subdev_core_ops ths8200_core_ops = {
        .log_status = ths8200_log_status,
        .s_power = ths8200_s_power,
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .g_register = ths8200_g_register,
        .s_register = ths8200_s_register,
#endif
};

/* -----------------------------------------------------------------------------
 * V4L2 subdev video operations
 */

static int ths8200_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct ths8200_state *state = to_state(sd);

        if (enable && !state->power_on)
                ths8200_s_power(sd, true);

        ths8200_write_and_or(sd, THS8200_CHIP_CTL, 0xfe,
                             (enable ? 0x01 : 0x00));

        v4l2_dbg(1, debug, sd, "%s: %sable\n",
                 __func__, (enable ? "en" : "dis"));

        return 0;
}

static void ths8200_core_init(struct v4l2_subdev *sd)
{
        /* setup clocks */
        ths8200_write_and_or(sd, THS8200_CHIP_CTL, 0x3f, 0xc0);

        /**** Data path control (DATA) ****/
        /* Set FSADJ 700 mV,
         * bypass 422-444 interpolation,
         * input format 30 bit RGB444
         */
        ths8200_write(sd, THS8200_DATA_CNTL, 0x70);

        /* DTG Mode (Video blocked during blanking
         * VESA slave
         */
        ths8200_write(sd, THS8200_DTG1_MODE, 0x87);

        /**** Display Timing Generator Control, Part 1 (DTG1). ****/

        /* Disable embedded syncs on the output by setting
         * the amplitude to zero for all channels.
         */
        ths8200_write(sd, THS8200_DTG1_Y_SYNC_MSB, 0x2a);
        ths8200_write(sd, THS8200_DTG1_CBCR_SYNC_MSB, 0x2a);
}

static void ths8200_setup(struct v4l2_subdev *sd, struct v4l2_bt_timings *bt)
{
        uint8_t polarity = 0;
        uint16_t line_start_active_video = (bt->vsync + bt->vbackporch);
        uint16_t line_start_front_porch  = (vtotal(bt) - bt->vfrontporch);

        /*** System ****/
        /* Set chip in reset while it is configured */
        ths8200_s_stream(sd, false);

        /* configure video output timings */
        ths8200_write(sd, THS8200_DTG1_SPEC_A, bt->hsync);
        ths8200_write(sd, THS8200_DTG1_SPEC_B, bt->hfrontporch);

        /* Zero for progressive scan formats.*/
        if (!bt->interlaced)
                ths8200_write(sd, THS8200_DTG1_SPEC_C, 0x00);

        /* Distance from leading edge of h sync to start of active video.
         * MSB in 0x2b
         */
        ths8200_write(sd, THS8200_DTG1_SPEC_D_LSB,
                      (bt->hbackporch + bt->hsync) & 0xff);
        /* Zero for SDTV-mode. MSB in 0x2b */
        ths8200_write(sd, THS8200_DTG1_SPEC_E_LSB, 0x00);
        /*
         * MSB for dtg1_spec(d/e/h). See comment for
         * corresponding LSB registers.
         */
        ths8200_write(sd, THS8200_DTG1_SPEC_DEH_MSB,
                      ((bt->hbackporch + bt->hsync) & 0x100) >> 1);

        /* h front porch */
        ths8200_write(sd, THS8200_DTG1_SPEC_K_LSB, (bt->hfrontporch) & 0xff);
        ths8200_write(sd, THS8200_DTG1_SPEC_K_MSB,
                      ((bt->hfrontporch) & 0x700) >> 8);

        /* Half the line length. Used to calculate SDTV line types. */
        ths8200_write(sd, THS8200_DTG1_SPEC_G_LSB, (htotal(bt)/2) & 0xff);
        ths8200_write(sd, THS8200_DTG1_SPEC_G_MSB,
                      ((htotal(bt)/2) >> 8) & 0x0f);

        /* Total pixels per line (ex. 720p: 1650) */
        ths8200_write(sd, THS8200_DTG1_TOT_PIXELS_MSB, htotal(bt) >> 8);
        ths8200_write(sd, THS8200_DTG1_TOT_PIXELS_LSB, htotal(bt) & 0xff);

        /* Frame height and field height */
        /* Field height should be programmed higher than frame_size for
         * progressive scan formats
         */
        ths8200_write(sd, THS8200_DTG1_FRAME_FIELD_SZ_MSB,
                      ((vtotal(bt) >> 4) & 0xf0) + 0x7);
        ths8200_write(sd, THS8200_DTG1_FRAME_SZ_LSB, vtotal(bt) & 0xff);

        /* Should be programmed higher than frame_size
         * for progressive formats
         */
        if (!bt->interlaced)
                ths8200_write(sd, THS8200_DTG1_FIELD_SZ_LSB, 0xff);

        /**** Display Timing Generator Control, Part 2 (DTG2). ****/
        /* Set breakpoint line numbers and types
         * THS8200 generates line types with different properties. A line type
         * that sets all the RGB-outputs to zero is used in the blanking areas,
         * while a line type that enable the RGB-outputs is used in active video
         * area. The line numbers for start of active video, start of front
         * porch and after the last line in the frame must be set with the
         * corresponding line types.
         *
         * Line types:
         * 0x9 - Full normal sync pulse: Blocks data when dtg1_pass is off.
         *       Used in blanking area.
         * 0x0 - Active video: Video data is always passed. Used in active
         *       video area.
         */
        ths8200_write_and_or(sd, THS8200_DTG2_BP1_2_MSB, 0x88,
                             ((line_start_active_video >> 4) & 0x70) +
                             ((line_start_front_porch >> 8) & 0x07));
        ths8200_write(sd, THS8200_DTG2_BP3_4_MSB, ((vtotal(bt)) >> 4) & 0x70);
        ths8200_write(sd, THS8200_DTG2_BP1_LSB, line_start_active_video & 0xff);
        ths8200_write(sd, THS8200_DTG2_BP2_LSB, line_start_front_porch & 0xff);
        ths8200_write(sd, THS8200_DTG2_BP3_LSB, (vtotal(bt)) & 0xff);

        /* line types */
        ths8200_write(sd, THS8200_DTG2_LINETYPE1, 0x90);
        ths8200_write(sd, THS8200_DTG2_LINETYPE2, 0x90);

        /* h sync width transmitted */
        ths8200_write(sd, THS8200_DTG2_HLENGTH_LSB, bt->hsync & 0xff);
        ths8200_write_and_or(sd, THS8200_DTG2_HLENGTH_LSB_HDLY_MSB, 0x3f,
                             (bt->hsync >> 2) & 0xc0);

        /* The pixel value h sync is asserted on */
        ths8200_write_and_or(sd, THS8200_DTG2_HLENGTH_LSB_HDLY_MSB, 0xe0,
                             (htotal(bt) >> 8) & 0x1f);
        ths8200_write(sd, THS8200_DTG2_HLENGTH_HDLY_LSB, htotal(bt));

        /* v sync width transmitted */
        ths8200_write(sd, THS8200_DTG2_VLENGTH1_LSB, (bt->vsync) & 0xff);
        ths8200_write_and_or(sd, THS8200_DTG2_VLENGTH1_MSB_VDLY1_MSB, 0x3f,
                             ((bt->vsync) >> 2) & 0xc0);

        /* The pixel value v sync is asserted on */
        ths8200_write_and_or(sd, THS8200_DTG2_VLENGTH1_MSB_VDLY1_MSB, 0xf8,
                             (vtotal(bt)>>8) & 0x7);
        ths8200_write(sd, THS8200_DTG2_VDLY1_LSB, vtotal(bt));

        /* For progressive video vlength2 must be set to all 0 and vdly2 must
         * be set to all 1.
         */
        ths8200_write(sd, THS8200_DTG2_VLENGTH2_LSB, 0x00);
        ths8200_write(sd, THS8200_DTG2_VLENGTH2_MSB_VDLY2_MSB, 0x07);
        ths8200_write(sd, THS8200_DTG2_VDLY2_LSB, 0xff);

        /* Internal delay factors to synchronize the sync pulses and the data */
        /* Experimental values delays (hor 4, ver 1) */
        ths8200_write(sd, THS8200_DTG2_HS_IN_DLY_MSB, (htotal(bt)>>8) & 0x1f);
        ths8200_write(sd, THS8200_DTG2_HS_IN_DLY_LSB, (htotal(bt) - 4) & 0xff);
        ths8200_write(sd, THS8200_DTG2_VS_IN_DLY_MSB, 0);
        ths8200_write(sd, THS8200_DTG2_VS_IN_DLY_LSB, 1);

        /* Polarity of received and transmitted sync signals */
        if (bt->polarities & V4L2_DV_HSYNC_POS_POL) {
                polarity |= 0x01; /* HS_IN */
                polarity |= 0x08; /* HS_OUT */
        }
        if (bt->polarities & V4L2_DV_VSYNC_POS_POL) {
                polarity |= 0x02; /* VS_IN */
                polarity |= 0x10; /* VS_OUT */
        }

        /* RGB mode, no embedded timings */
        /* Timing of video input bus is derived from HS, VS, and FID dedicated
         * inputs
         */
        ths8200_write(sd, THS8200_DTG2_CNTL, 0x47 | polarity);

        /* leave reset */
        ths8200_s_stream(sd, true);

        v4l2_dbg(1, debug, sd, "%s: frame %dx%d, polarity %d\n"
                 "horizontal: front porch %d, back porch %d, sync %d\n"
                 "vertical: sync %d\n", __func__, htotal(bt), vtotal(bt),
                 polarity, bt->hfrontporch, bt->hbackporch,
                 bt->hsync, bt->vsync);
}

static int ths8200_s_dv_timings(struct v4l2_subdev *sd,
                                struct v4l2_dv_timings *timings)
{
        struct ths8200_state *state = to_state(sd);
        int i;

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

        if (timings->type != V4L2_DV_BT_656_1120)
                return -EINVAL;

        /* TODO Support interlaced formats */
        if (timings->bt.interlaced) {
                v4l2_dbg(1, debug, sd, "TODO Support interlaced formats\n");
                return -EINVAL;
        }

        for (i = 0; i < ARRAY_SIZE(ths8200_timings); i++) {
                if (v4l_match_dv_timings(&ths8200_timings[i], timings, 10))
                        break;
        }

        if (i == ARRAY_SIZE(ths8200_timings)) {
                v4l2_dbg(1, debug, sd, "Unsupported format\n");
                return -EINVAL;
        }

        timings->bt.flags &= ~V4L2_DV_FL_REDUCED_FPS;

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

        ths8200_setup(sd, &timings->bt);

        return 0;
}

static int ths8200_g_dv_timings(struct v4l2_subdev *sd,
                                struct v4l2_dv_timings *timings)
{
        struct ths8200_state *state = to_state(sd);

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

        *timings = state->dv_timings;

        return 0;
}

static int ths8200_enum_dv_timings(struct v4l2_subdev *sd,
                                   struct v4l2_enum_dv_timings *timings)
{
        /* Check requested format index is within range */
        if (timings->index >= ARRAY_SIZE(ths8200_timings))
                return -EINVAL;

        timings->timings = ths8200_timings[timings->index];

        return 0;
}

static int ths8200_dv_timings_cap(struct v4l2_subdev *sd,
                                  struct v4l2_dv_timings_cap *cap)
{
        cap->type = V4L2_DV_BT_656_1120;
        cap->bt.max_width = 1920;
        cap->bt.max_height = 1080;
        cap->bt.min_pixelclock = 27000000;
        cap->bt.max_pixelclock = 148500000;
        cap->bt.standards = V4L2_DV_BT_STD_CEA861;
        cap->bt.capabilities = V4L2_DV_BT_CAP_PROGRESSIVE;

        return 0;
}

/* Specific video subsystem operation handlers */
static const struct v4l2_subdev_video_ops ths8200_video_ops = {
        .s_stream = ths8200_s_stream,
        .s_dv_timings = ths8200_s_dv_timings,
        .g_dv_timings = ths8200_g_dv_timings,
        .enum_dv_timings = ths8200_enum_dv_timings,
        .dv_timings_cap = ths8200_dv_timings_cap,
};

/* V4L2 top level operation handlers */
static const struct v4l2_subdev_ops ths8200_ops = {
        .core  = &ths8200_core_ops,
        .video = &ths8200_video_ops,
};

static int ths8200_probe(struct i2c_client *client,
                         const struct i2c_device_id *id)
{
        struct ths8200_state *state;
        struct v4l2_subdev *sd;

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

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

        sd = &state->sd;
        v4l2_i2c_subdev_init(sd, client, &ths8200_ops);

        state->chip_version = ths8200_read(sd, THS8200_VERSION);
        v4l2_dbg(1, debug, sd, "chip version 0x%x\n", state->chip_version);

        ths8200_core_init(sd);

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

        return 0;
}

static int ths8200_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);

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

        ths8200_s_power(sd, false);

        v4l2_device_unregister_subdev(sd);

        return 0;
}

static struct i2c_device_id ths8200_id[] = {
        { "ths8200", 0 },
        {},
};
MODULE_DEVICE_TABLE(i2c, ths8200_id);

static struct i2c_driver ths8200_driver = {
        .driver = {
                .owner = THIS_MODULE,
                .name = "ths8200",
        },
        .probe = ths8200_probe,
        .remove = ths8200_remove,
        .id_table = ths8200_id,
};

module_i2c_driver(ths8200_driver);