/*
 * Copyright © 2014 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * 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.
 *
 * Author: Shobhit Kumar <shobhit.kumar@intel.com>
 *
 */

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_edid.h>
#include <drm/i915_drm.h>
#include <linux/gpio/consumer.h>
#include <linux/slab.h>
#include <video/mipi_display.h>
#include <video/mipi_display.h>
#include "i915_drv.h"
#include "intel_drv.h"
#include "intel_dsi.h"

#define MIPI_TRANSFER_MODE_SHIFT        0
#define MIPI_VIRTUAL_CHANNEL_SHIFT      1
#define MIPI_PORT_SHIFT                 3

#define PREPARE_CNT_MAX         0x3F
#define EXIT_ZERO_CNT_MAX       0x3F
#define CLK_ZERO_CNT_MAX        0xFF
#define TRAIL_CNT_MAX           0x1F

#define NS_KHZ_RATIO 1000000

/* base offsets for gpio pads */
#define VLV_GPIO_NC_0_HV_DDI0_HPD       0x4130
#define VLV_GPIO_NC_1_HV_DDI0_DDC_SDA   0x4120
#define VLV_GPIO_NC_2_HV_DDI0_DDC_SCL   0x4110
#define VLV_GPIO_NC_3_PANEL0_VDDEN      0x4140
#define VLV_GPIO_NC_4_PANEL0_BKLTEN     0x4150
#define VLV_GPIO_NC_5_PANEL0_BKLTCTL    0x4160
#define VLV_GPIO_NC_6_HV_DDI1_HPD       0x4180
#define VLV_GPIO_NC_7_HV_DDI1_DDC_SDA   0x4190
#define VLV_GPIO_NC_8_HV_DDI1_DDC_SCL   0x4170
#define VLV_GPIO_NC_9_PANEL1_VDDEN      0x4100
#define VLV_GPIO_NC_10_PANEL1_BKLTEN    0x40E0
#define VLV_GPIO_NC_11_PANEL1_BKLTCTL   0x40F0

#define VLV_GPIO_PCONF0(base_offset)    (base_offset)
#define VLV_GPIO_PAD_VAL(base_offset)   ((base_offset) + 8)

struct gpio_map {
        u16 base_offset;
        bool init;
};

static struct gpio_map vlv_gpio_table[] = {
        { VLV_GPIO_NC_0_HV_DDI0_HPD },
        { VLV_GPIO_NC_1_HV_DDI0_DDC_SDA },
        { VLV_GPIO_NC_2_HV_DDI0_DDC_SCL },
        { VLV_GPIO_NC_3_PANEL0_VDDEN },
        { VLV_GPIO_NC_4_PANEL0_BKLTEN },
        { VLV_GPIO_NC_5_PANEL0_BKLTCTL },
        { VLV_GPIO_NC_6_HV_DDI1_HPD },
        { VLV_GPIO_NC_7_HV_DDI1_DDC_SDA },
        { VLV_GPIO_NC_8_HV_DDI1_DDC_SCL },
        { VLV_GPIO_NC_9_PANEL1_VDDEN },
        { VLV_GPIO_NC_10_PANEL1_BKLTEN },
        { VLV_GPIO_NC_11_PANEL1_BKLTCTL },
};

#define CHV_GPIO_IDX_START_N            0
#define CHV_GPIO_IDX_START_E            73
#define CHV_GPIO_IDX_START_SW           100
#define CHV_GPIO_IDX_START_SE           198

#define CHV_VBT_MAX_PINS_PER_FMLY       15

#define CHV_GPIO_PAD_CFG0(f, i)         (0x4400 + (f) * 0x400 + (i) * 8)
#define  CHV_GPIO_GPIOEN                (1 << 15)
#define  CHV_GPIO_GPIOCFG_GPIO          (0 << 8)
#define  CHV_GPIO_GPIOCFG_GPO           (1 << 8)
#define  CHV_GPIO_GPIOCFG_GPI           (2 << 8)
#define  CHV_GPIO_GPIOCFG_HIZ           (3 << 8)
#define  CHV_GPIO_GPIOTXSTATE(state)    ((!!(state)) << 1)

#define CHV_GPIO_PAD_CFG1(f, i)         (0x4400 + (f) * 0x400 + (i) * 8 + 4)
#define  CHV_GPIO_CFGLOCK               (1 << 31)

static inline enum port intel_dsi_seq_port_to_port(u8 port)
{
        return port ? PORT_C : PORT_A;
}

static const u8 *mipi_exec_send_packet(struct intel_dsi *intel_dsi,
                                       const u8 *data)
{
        struct mipi_dsi_device *dsi_device;
        u8 type, flags, seq_port;
        u16 len;
        enum port port;

        DRM_DEBUG_KMS("\n");

        flags = *data++;
        type = *data++;

        len = *((u16 *) data);
        data += 2;

        seq_port = (flags >> MIPI_PORT_SHIFT) & 3;

        /* For DSI single link on Port A & C, the seq_port value which is
         * parsed from Sequence Block#53 of VBT has been set to 0
         * Now, read/write of packets for the DSI single link on Port A and
         * Port C will based on the DVO port from VBT block 2.
         */
        if (intel_dsi->ports == (1 << PORT_C))
                port = PORT_C;
        else
                port = intel_dsi_seq_port_to_port(seq_port);

        dsi_device = intel_dsi->dsi_hosts[port]->device;
        if (!dsi_device) {
                DRM_DEBUG_KMS("no dsi device for port %c\n", port_name(port));
                goto out;
        }

        if ((flags >> MIPI_TRANSFER_MODE_SHIFT) & 1)
                dsi_device->mode_flags &= ~MIPI_DSI_MODE_LPM;
        else
                dsi_device->mode_flags |= MIPI_DSI_MODE_LPM;

        dsi_device->channel = (flags >> MIPI_VIRTUAL_CHANNEL_SHIFT) & 3;

        switch (type) {
        case MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM:
                mipi_dsi_generic_write(dsi_device, NULL, 0);
                break;
        case MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM:
                mipi_dsi_generic_write(dsi_device, data, 1);
                break;
        case MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM:
                mipi_dsi_generic_write(dsi_device, data, 2);
                break;
        case MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM:
        case MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM:
        case MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM:
                DRM_DEBUG_DRIVER("Generic Read not yet implemented or used\n");
                break;
        case MIPI_DSI_GENERIC_LONG_WRITE:
                mipi_dsi_generic_write(dsi_device, data, len);
                break;
        case MIPI_DSI_DCS_SHORT_WRITE:
                mipi_dsi_dcs_write_buffer(dsi_device, data, 1);
                break;
        case MIPI_DSI_DCS_SHORT_WRITE_PARAM:
                mipi_dsi_dcs_write_buffer(dsi_device, data, 2);
                break;
        case MIPI_DSI_DCS_READ:
                DRM_DEBUG_DRIVER("DCS Read not yet implemented or used\n");
                break;
        case MIPI_DSI_DCS_LONG_WRITE:
                mipi_dsi_dcs_write_buffer(dsi_device, data, len);
                break;
        }

        wait_for_dsi_fifo_empty(intel_dsi, port);

out:
        data += len;

        return data;
}

static const u8 *mipi_exec_delay(struct intel_dsi *intel_dsi, const u8 *data)
{
        u32 delay = *((const u32 *) data);

        DRM_DEBUG_KMS("\n");

        usleep_range(delay, delay + 10);
        data += 4;

        return data;
}

static void vlv_exec_gpio(struct drm_i915_private *dev_priv,
                          u8 gpio_source, u8 gpio_index, bool value)
{
        struct gpio_map *map;
        u16 pconf0, padval;
        u32 tmp;
        u8 port;

        if (gpio_index >= ARRAY_SIZE(vlv_gpio_table)) {
                DRM_DEBUG_KMS("unknown gpio index %u\n", gpio_index);
                return;
        }

        map = &vlv_gpio_table[gpio_index];

        if (dev_priv->vbt.dsi.seq_version >= 3) {
                /* XXX: this assumes vlv_gpio_table only has NC GPIOs. */
                port = IOSF_PORT_GPIO_NC;
        } else {
                if (gpio_source == 0) {
                        port = IOSF_PORT_GPIO_NC;
                } else if (gpio_source == 1) {
                        DRM_DEBUG_KMS("SC gpio not supported\n");
                        return;
                } else {
                        DRM_DEBUG_KMS("unknown gpio source %u\n", gpio_source);
                        return;
                }
        }

        pconf0 = VLV_GPIO_PCONF0(map->base_offset);
        padval = VLV_GPIO_PAD_VAL(map->base_offset);

        mutex_lock(&dev_priv->sb_lock);
        if (!map->init) {
                /* FIXME: remove constant below */
                vlv_iosf_sb_write(dev_priv, port, pconf0, 0x2000CC00);
                map->init = true;
        }

        tmp = 0x4 | value;
        vlv_iosf_sb_write(dev_priv, port, padval, tmp);
        mutex_unlock(&dev_priv->sb_lock);
}

static void chv_exec_gpio(struct drm_i915_private *dev_priv,
                          u8 gpio_source, u8 gpio_index, bool value)
{
        u16 cfg0, cfg1;
        u16 family_num;
        u8 port;

        if (dev_priv->vbt.dsi.seq_version >= 3) {
                if (gpio_index >= CHV_GPIO_IDX_START_SE) {
                        /* XXX: it's unclear whether 255->57 is part of SE. */
                        gpio_index -= CHV_GPIO_IDX_START_SE;
                        port = CHV_IOSF_PORT_GPIO_SE;
                } else if (gpio_index >= CHV_GPIO_IDX_START_SW) {
                        gpio_index -= CHV_GPIO_IDX_START_SW;
                        port = CHV_IOSF_PORT_GPIO_SW;
                } else if (gpio_index >= CHV_GPIO_IDX_START_E) {
                        gpio_index -= CHV_GPIO_IDX_START_E;
                        port = CHV_IOSF_PORT_GPIO_E;
                } else {
                        port = CHV_IOSF_PORT_GPIO_N;
                }
        } else {
                /* XXX: The spec is unclear about CHV GPIO on seq v2 */
                if (gpio_source != 0) {
                        DRM_DEBUG_KMS("unknown gpio source %u\n", gpio_source);
                        return;
                }

                if (gpio_index >= CHV_GPIO_IDX_START_E) {
                        DRM_DEBUG_KMS("invalid gpio index %u for GPIO N\n",
                                      gpio_index);
                        return;
                }

                port = CHV_IOSF_PORT_GPIO_N;
        }

        family_num = gpio_index / CHV_VBT_MAX_PINS_PER_FMLY;
        gpio_index = gpio_index % CHV_VBT_MAX_PINS_PER_FMLY;

        cfg0 = CHV_GPIO_PAD_CFG0(family_num, gpio_index);
        cfg1 = CHV_GPIO_PAD_CFG1(family_num, gpio_index);

        mutex_lock(&dev_priv->sb_lock);
        vlv_iosf_sb_write(dev_priv, port, cfg1, 0);
        vlv_iosf_sb_write(dev_priv, port, cfg0,
                          CHV_GPIO_GPIOEN | CHV_GPIO_GPIOCFG_GPO |
                          CHV_GPIO_GPIOTXSTATE(value));
        mutex_unlock(&dev_priv->sb_lock);
}

static void bxt_exec_gpio(struct drm_i915_private *dev_priv,
                          u8 gpio_source, u8 gpio_index, bool value)
{
        /* XXX: this table is a quick ugly hack. */
        static struct gpio_desc *bxt_gpio_table[U8_MAX + 1];
        struct gpio_desc *gpio_desc = bxt_gpio_table[gpio_index];

        if (!gpio_desc) {
                gpio_desc = devm_gpiod_get_index(dev_priv->drm.dev,
                                                 NULL, gpio_index,
                                                 value ? GPIOD_OUT_LOW :
                                                 GPIOD_OUT_HIGH);

                if (IS_ERR_OR_NULL(gpio_desc)) {
                        DRM_ERROR("GPIO index %u request failed (%ld)\n",
                                  gpio_index, PTR_ERR(gpio_desc));
                        return;
                }

                bxt_gpio_table[gpio_index] = gpio_desc;
        }

        gpiod_set_value(gpio_desc, value);
}

static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data)
{
        struct drm_device *dev = intel_dsi->base.base.dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        u8 gpio_source, gpio_index = 0, gpio_number;
        bool value;

        DRM_DEBUG_KMS("\n");

        if (dev_priv->vbt.dsi.seq_version >= 3)
                gpio_index = *data++;

        gpio_number = *data++;

        /* gpio source in sequence v2 only */
        if (dev_priv->vbt.dsi.seq_version == 2)
                gpio_source = (*data >> 1) & 3;
        else
                gpio_source = 0;

        /* pull up/down */
        value = *data++ & 1;

        if (IS_VALLEYVIEW(dev_priv))
                vlv_exec_gpio(dev_priv, gpio_source, gpio_number, value);
        else if (IS_CHERRYVIEW(dev_priv))
                chv_exec_gpio(dev_priv, gpio_source, gpio_number, value);
        else
                bxt_exec_gpio(dev_priv, gpio_source, gpio_index, value);

        return data;
}

static const u8 *mipi_exec_i2c(struct intel_dsi *intel_dsi, const u8 *data)
{
        DRM_DEBUG_KMS("Skipping I2C element execution\n");

        return data + *(data + 6) + 7;
}

static const u8 *mipi_exec_spi(struct intel_dsi *intel_dsi, const u8 *data)
{
        DRM_DEBUG_KMS("Skipping SPI element execution\n");

        return data + *(data + 5) + 6;
}

static const u8 *mipi_exec_pmic(struct intel_dsi *intel_dsi, const u8 *data)
{
        DRM_DEBUG_KMS("Skipping PMIC element execution\n");

        return data + 15;
}

typedef const u8 * (*fn_mipi_elem_exec)(struct intel_dsi *intel_dsi,
                                        const u8 *data);
static const fn_mipi_elem_exec exec_elem[] = {
        [MIPI_SEQ_ELEM_SEND_PKT] = mipi_exec_send_packet,
        [MIPI_SEQ_ELEM_DELAY] = mipi_exec_delay,
        [MIPI_SEQ_ELEM_GPIO] = mipi_exec_gpio,
        [MIPI_SEQ_ELEM_I2C] = mipi_exec_i2c,
        [MIPI_SEQ_ELEM_SPI] = mipi_exec_spi,
        [MIPI_SEQ_ELEM_PMIC] = mipi_exec_pmic,
};

/*
 * MIPI Sequence from VBT #53 parsing logic
 * We have already separated each seqence during bios parsing
 * Following is generic execution function for any sequence
 */

static const char * const seq_name[] = {
        [MIPI_SEQ_DEASSERT_RESET] = "MIPI_SEQ_DEASSERT_RESET",
        [MIPI_SEQ_INIT_OTP] = "MIPI_SEQ_INIT_OTP",
        [MIPI_SEQ_DISPLAY_ON] = "MIPI_SEQ_DISPLAY_ON",
        [MIPI_SEQ_DISPLAY_OFF]  = "MIPI_SEQ_DISPLAY_OFF",
        [MIPI_SEQ_ASSERT_RESET] = "MIPI_SEQ_ASSERT_RESET",
        [MIPI_SEQ_BACKLIGHT_ON] = "MIPI_SEQ_BACKLIGHT_ON",
        [MIPI_SEQ_BACKLIGHT_OFF] = "MIPI_SEQ_BACKLIGHT_OFF",
        [MIPI_SEQ_TEAR_ON] = "MIPI_SEQ_TEAR_ON",
        [MIPI_SEQ_TEAR_OFF] = "MIPI_SEQ_TEAR_OFF",
        [MIPI_SEQ_POWER_ON] = "MIPI_SEQ_POWER_ON",
        [MIPI_SEQ_POWER_OFF] = "MIPI_SEQ_POWER_OFF",
};

static const char *sequence_name(enum mipi_seq seq_id)
{
        if (seq_id < ARRAY_SIZE(seq_name) && seq_name[seq_id])
                return seq_name[seq_id];
        else
                return "(unknown)";
}

void intel_dsi_vbt_exec_sequence(struct intel_dsi *intel_dsi,
                                 enum mipi_seq seq_id)
{
        struct drm_i915_private *dev_priv = to_i915(intel_dsi->base.base.dev);
        const u8 *data;
        fn_mipi_elem_exec mipi_elem_exec;

        if (WARN_ON(seq_id >= ARRAY_SIZE(dev_priv->vbt.dsi.sequence)))
                return;

        data = dev_priv->vbt.dsi.sequence[seq_id];
        if (!data)
                return;

        WARN_ON(*data != seq_id);

        DRM_DEBUG_KMS("Starting MIPI sequence %d - %s\n",
                      seq_id, sequence_name(seq_id));

        /* Skip Sequence Byte. */
        data++;

        /* Skip Size of Sequence. */
        if (dev_priv->vbt.dsi.seq_version >= 3)
                data += 4;

        while (1) {
                u8 operation_byte = *data++;
                u8 operation_size = 0;

                if (operation_byte == MIPI_SEQ_ELEM_END)
                        break;

                if (operation_byte < ARRAY_SIZE(exec_elem))
                        mipi_elem_exec = exec_elem[operation_byte];
                else
                        mipi_elem_exec = NULL;

                /* Size of Operation. */
                if (dev_priv->vbt.dsi.seq_version >= 3)
                        operation_size = *data++;

                if (mipi_elem_exec) {
                        const u8 *next = data + operation_size;

                        data = mipi_elem_exec(intel_dsi, data);

                        /* Consistency check if we have size. */
                        if (operation_size && data != next) {
                                DRM_ERROR("Inconsistent operation size\n");
                                return;
                        }
                } else if (operation_size) {
                        /* We have size, skip. */
                        DRM_DEBUG_KMS("Unsupported MIPI operation byte %u\n",
                                      operation_byte);
                        data += operation_size;
                } else {
                        /* No size, can't skip without parsing. */
                        DRM_ERROR("Unsupported MIPI operation byte %u\n",
                                  operation_byte);
                        return;
                }
        }
}

int intel_dsi_vbt_get_modes(struct intel_dsi *intel_dsi)
{
        struct intel_connector *connector = intel_dsi->attached_connector;
        struct drm_device *dev = intel_dsi->base.base.dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct drm_display_mode *mode;

        mode = drm_mode_duplicate(dev, dev_priv->vbt.lfp_lvds_vbt_mode);
        if (!mode)
                return 0;

        mode->type |= DRM_MODE_TYPE_PREFERRED;

        drm_mode_probed_add(&connector->base, mode);

        return 1;
}

bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16 panel_id)
{
        struct drm_device *dev = intel_dsi->base.base.dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct mipi_config *mipi_config = dev_priv->vbt.dsi.config;
        struct mipi_pps_data *pps = dev_priv->vbt.dsi.pps;
        struct drm_display_mode *mode = dev_priv->vbt.lfp_lvds_vbt_mode;
        u32 bpp;
        u32 tlpx_ns, extra_byte_count, bitrate, tlpx_ui;
        u32 ui_num, ui_den;
        u32 prepare_cnt, exit_zero_cnt, clk_zero_cnt, trail_cnt;
        u32 ths_prepare_ns, tclk_trail_ns;
        u32 tclk_prepare_clkzero, ths_prepare_hszero;
        u32 lp_to_hs_switch, hs_to_lp_switch;
        u32 pclk, computed_ddr;
        u32 mul;
        u16 burst_mode_ratio;
        enum port port;

        DRM_DEBUG_KMS("\n");

        intel_dsi->eotp_pkt = mipi_config->eot_pkt_disabled ? 0 : 1;
        intel_dsi->clock_stop = mipi_config->enable_clk_stop ? 1 : 0;
        intel_dsi->lane_count = mipi_config->lane_cnt + 1;
        intel_dsi->pixel_format =
                        pixel_format_from_register_bits(
                                mipi_config->videomode_color_format << 7);
        bpp = mipi_dsi_pixel_format_to_bpp(intel_dsi->pixel_format);

        intel_dsi->dual_link = mipi_config->dual_link;
        intel_dsi->pixel_overlap = mipi_config->pixel_overlap;
        intel_dsi->operation_mode = mipi_config->is_cmd_mode;
        intel_dsi->video_mode_format = mipi_config->video_transfer_mode;
        intel_dsi->escape_clk_div = mipi_config->byte_clk_sel;
        intel_dsi->lp_rx_timeout = mipi_config->lp_rx_timeout;
        intel_dsi->turn_arnd_val = mipi_config->turn_around_timeout;
        intel_dsi->rst_timer_val = mipi_config->device_reset_timer;
        intel_dsi->init_count = mipi_config->master_init_timer;
        intel_dsi->bw_timer = mipi_config->dbi_bw_timer;
        intel_dsi->video_frmt_cfg_bits =
                mipi_config->bta_enabled ? DISABLE_VIDEO_BTA : 0;

        pclk = mode->clock;

        /* In dual link mode each port needs half of pixel clock */
        if (intel_dsi->dual_link) {
                pclk = pclk / 2;

                /* we can enable pixel_overlap if needed by panel. In this
                 * case we need to increase the pixelclock for extra pixels
                 */
                if (intel_dsi->dual_link == DSI_DUAL_LINK_FRONT_BACK) {
                        pclk += DIV_ROUND_UP(mode->vtotal *
                                                intel_dsi->pixel_overlap *
                                                60, 1000);
                }
        }

        /* Burst Mode Ratio
         * Target ddr frequency from VBT / non burst ddr freq
         * multiply by 100 to preserve remainder
         */
        if (intel_dsi->video_mode_format == VIDEO_MODE_BURST) {
                if (mipi_config->target_burst_mode_freq) {
                        computed_ddr = (pclk * bpp) / intel_dsi->lane_count;

                        if (mipi_config->target_burst_mode_freq <
                                                                computed_ddr) {
                                DRM_ERROR("Burst mode freq is less than computed\n");
                                return false;
                        }

                        burst_mode_ratio = DIV_ROUND_UP(
                                mipi_config->target_burst_mode_freq * 100,
                                computed_ddr);

                        pclk = DIV_ROUND_UP(pclk * burst_mode_ratio, 100);
                } else {
                        DRM_ERROR("Burst mode target is not set\n");
                        return false;
                }
        } else
                burst_mode_ratio = 100;

        intel_dsi->burst_mode_ratio = burst_mode_ratio;
        intel_dsi->pclk = pclk;

        bitrate = (pclk * bpp) / intel_dsi->lane_count;

        switch (intel_dsi->escape_clk_div) {
        case 0:
                tlpx_ns = 50;
                break;
        case 1:
                tlpx_ns = 100;
                break;

        case 2:
                tlpx_ns = 200;
                break;
        default:
                tlpx_ns = 50;
                break;
        }

        switch (intel_dsi->lane_count) {
        case 1:
        case 2:
                extra_byte_count = 2;
                break;
        case 3:
                extra_byte_count = 4;
                break;
        case 4:
        default:
                extra_byte_count = 3;
                break;
        }

        /* in Kbps */
        ui_num = NS_KHZ_RATIO;
        ui_den = bitrate;

        tclk_prepare_clkzero = mipi_config->tclk_prepare_clkzero;
        ths_prepare_hszero = mipi_config->ths_prepare_hszero;

        /*
         * B060
         * LP byte clock = TLPX/ (8UI)
         */
        intel_dsi->lp_byte_clk = DIV_ROUND_UP(tlpx_ns * ui_den, 8 * ui_num);

        /* DDR clock period = 2 * UI
         * UI(sec) = 1/(bitrate * 10^3) (bitrate is in KHZ)
         * UI(nsec) = 10^6 / bitrate
         * DDR clock period (nsec) = 2 * UI = (2 * 10^6)/ bitrate
         * DDR clock count  = ns_value / DDR clock period
         *
         * For GEMINILAKE dphy_param_reg will be programmed in terms of
         * HS byte clock count for other platform in HS ddr clock count
         */
        mul = IS_GEMINILAKE(dev_priv) ? 8 : 2;
        ths_prepare_ns = max(mipi_config->ths_prepare,
                             mipi_config->tclk_prepare);

        /* prepare count */
        prepare_cnt = DIV_ROUND_UP(ths_prepare_ns * ui_den, ui_num * mul);

        /* exit zero count */
        exit_zero_cnt = DIV_ROUND_UP(
                                (ths_prepare_hszero - ths_prepare_ns) * ui_den,
                                ui_num * mul
                                );

        /*
         * Exit zero is unified val ths_zero and ths_exit
         * minimum value for ths_exit = 110ns
         * min (exit_zero_cnt * 2) = 110/UI
         * exit_zero_cnt = 55/UI
         */
        if (exit_zero_cnt < (55 * ui_den / ui_num) && (55 * ui_den) % ui_num)
                exit_zero_cnt += 1;

        /* clk zero count */
        clk_zero_cnt = DIV_ROUND_UP(
                                (tclk_prepare_clkzero - ths_prepare_ns)
                                * ui_den, ui_num * mul);

        /* trail count */
        tclk_trail_ns = max(mipi_config->tclk_trail, mipi_config->ths_trail);
        trail_cnt = DIV_ROUND_UP(tclk_trail_ns * ui_den, ui_num * mul);

        if (prepare_cnt > PREPARE_CNT_MAX ||
                exit_zero_cnt > EXIT_ZERO_CNT_MAX ||
                clk_zero_cnt > CLK_ZERO_CNT_MAX ||
                trail_cnt > TRAIL_CNT_MAX)
                DRM_DEBUG_DRIVER("Values crossing maximum limits, restricting to max values\n");

        if (prepare_cnt > PREPARE_CNT_MAX)
                prepare_cnt = PREPARE_CNT_MAX;

        if (exit_zero_cnt > EXIT_ZERO_CNT_MAX)
                exit_zero_cnt = EXIT_ZERO_CNT_MAX;

        if (clk_zero_cnt > CLK_ZERO_CNT_MAX)
                clk_zero_cnt = CLK_ZERO_CNT_MAX;

        if (trail_cnt > TRAIL_CNT_MAX)
                trail_cnt = TRAIL_CNT_MAX;

        /* B080 */
        intel_dsi->dphy_reg = exit_zero_cnt << 24 | trail_cnt << 16 |
                                                clk_zero_cnt << 8 | prepare_cnt;

        /*
         * LP to HS switch count = 4TLPX + PREP_COUNT * mul + EXIT_ZERO_COUNT *
         *                                      mul + 10UI + Extra Byte Count
         *
         * HS to LP switch count = THS-TRAIL + 2TLPX + Extra Byte Count
         * Extra Byte Count is calculated according to number of lanes.
         * High Low Switch Count is the Max of LP to HS and
         * HS to LP switch count
         *
         */
        tlpx_ui = DIV_ROUND_UP(tlpx_ns * ui_den, ui_num);

        /* B044 */
        /* FIXME:
         * The comment above does not match with the code */
        lp_to_hs_switch = DIV_ROUND_UP(4 * tlpx_ui + prepare_cnt * mul +
                                                exit_zero_cnt * mul + 10, 8);

        hs_to_lp_switch = DIV_ROUND_UP(mipi_config->ths_trail + 2 * tlpx_ui, 8);

        intel_dsi->hs_to_lp_count = max(lp_to_hs_switch, hs_to_lp_switch);
        intel_dsi->hs_to_lp_count += extra_byte_count;

        /* B088 */
        /* LP -> HS for clock lanes
         * LP clk sync + LP11 + LP01 + tclk_prepare + tclk_zero +
         *                                              extra byte count
         * 2TPLX + 1TLPX + 1 TPLX(in ns) + prepare_cnt * 2 + clk_zero_cnt *
         *                                      2(in UI) + extra byte count
         * In byteclks = (4TLPX + prepare_cnt * 2 + clk_zero_cnt *2 (in UI)) /
         *                                      8 + extra byte count
         */
        intel_dsi->clk_lp_to_hs_count =
                DIV_ROUND_UP(
                        4 * tlpx_ui + prepare_cnt * 2 +
                        clk_zero_cnt * 2,
                        8);

        intel_dsi->clk_lp_to_hs_count += extra_byte_count;

        /* HS->LP for Clock Lanes
         * Low Power clock synchronisations + 1Tx byteclk + tclk_trail +
         *                                              Extra byte count
         * 2TLPX + 8UI + (trail_count*2)(in UI) + Extra byte count
         * In byteclks = (2*TLpx(in UI) + trail_count*2 +8)(in UI)/8 +
         *                                              Extra byte count
         */
        intel_dsi->clk_hs_to_lp_count =
                DIV_ROUND_UP(2 * tlpx_ui + trail_cnt * 2 + 8,
                        8);
        intel_dsi->clk_hs_to_lp_count += extra_byte_count;

        DRM_DEBUG_KMS("Pclk %d\n", intel_dsi->pclk);
        DRM_DEBUG_KMS("Pixel overlap %d\n", intel_dsi->pixel_overlap);
        DRM_DEBUG_KMS("Lane count %d\n", intel_dsi->lane_count);
        DRM_DEBUG_KMS("DPHY param reg 0x%x\n", intel_dsi->dphy_reg);
        DRM_DEBUG_KMS("Video mode format %s\n",
                      intel_dsi->video_mode_format == VIDEO_MODE_NON_BURST_WITH_SYNC_PULSE ?
                      "non-burst with sync pulse" :
                      intel_dsi->video_mode_format == VIDEO_MODE_NON_BURST_WITH_SYNC_EVENTS ?
                      "non-burst with sync events" :
                      intel_dsi->video_mode_format == VIDEO_MODE_BURST ?
                      "burst" : "<unknown>");
        DRM_DEBUG_KMS("Burst mode ratio %d\n", intel_dsi->burst_mode_ratio);
        DRM_DEBUG_KMS("Reset timer %d\n", intel_dsi->rst_timer_val);
        DRM_DEBUG_KMS("Eot %s\n", enableddisabled(intel_dsi->eotp_pkt));
        DRM_DEBUG_KMS("Clockstop %s\n", enableddisabled(!intel_dsi->clock_stop));
        DRM_DEBUG_KMS("Mode %s\n", intel_dsi->operation_mode ? "command" : "video");
        if (intel_dsi->dual_link == DSI_DUAL_LINK_FRONT_BACK)
                DRM_DEBUG_KMS("Dual link: DSI_DUAL_LINK_FRONT_BACK\n");
        else if (intel_dsi->dual_link == DSI_DUAL_LINK_PIXEL_ALT)
                DRM_DEBUG_KMS("Dual link: DSI_DUAL_LINK_PIXEL_ALT\n");
        else
                DRM_DEBUG_KMS("Dual link: NONE\n");
        DRM_DEBUG_KMS("Pixel Format %d\n", intel_dsi->pixel_format);
        DRM_DEBUG_KMS("TLPX %d\n", intel_dsi->escape_clk_div);
        DRM_DEBUG_KMS("LP RX Timeout 0x%x\n", intel_dsi->lp_rx_timeout);
        DRM_DEBUG_KMS("Turnaround Timeout 0x%x\n", intel_dsi->turn_arnd_val);
        DRM_DEBUG_KMS("Init Count 0x%x\n", intel_dsi->init_count);
        DRM_DEBUG_KMS("HS to LP Count 0x%x\n", intel_dsi->hs_to_lp_count);
        DRM_DEBUG_KMS("LP Byte Clock %d\n", intel_dsi->lp_byte_clk);
        DRM_DEBUG_KMS("DBI BW Timer 0x%x\n", intel_dsi->bw_timer);
        DRM_DEBUG_KMS("LP to HS Clock Count 0x%x\n", intel_dsi->clk_lp_to_hs_count);
        DRM_DEBUG_KMS("HS to LP Clock Count 0x%x\n", intel_dsi->clk_hs_to_lp_count);
        DRM_DEBUG_KMS("BTA %s\n",
                        enableddisabled(!(intel_dsi->video_frmt_cfg_bits & DISABLE_VIDEO_BTA)));

        /* delays in VBT are in unit of 100us, so need to convert
         * here in ms
         * Delay (100us) * 100 /1000 = Delay / 10 (ms) */
        intel_dsi->backlight_off_delay = pps->bl_disable_delay / 10;
        intel_dsi->backlight_on_delay = pps->bl_enable_delay / 10;
        intel_dsi->panel_on_delay = pps->panel_on_delay / 10;
        intel_dsi->panel_off_delay = pps->panel_off_delay / 10;
        intel_dsi->panel_pwr_cycle_delay = pps->panel_power_cycle_delay / 10;

        /* a regular driver would get the device in probe */
        for_each_dsi_port(port, intel_dsi->ports) {
                mipi_dsi_attach(intel_dsi->dsi_hosts[port]->device);
        }

        return true;
}