// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2009 Nokia Corporation
 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
 *
 * Some code and ideas taken from drivers/video/omap/ driver
 * by Imre Deak.
 */

#define DSS_SUBSYS_NAME "DPI"

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/string.h>
#include <linux/sys_soc.h>

#include <drm/drm_bridge.h>

#include "dss.h"
#include "omapdss.h"

struct dpi_data {
        struct platform_device *pdev;
        enum dss_model dss_model;
        struct dss_device *dss;
        unsigned int id;

        struct regulator *vdds_dsi_reg;
        enum dss_clk_source clk_src;
        struct dss_pll *pll;

        struct dss_lcd_mgr_config mgr_config;
        unsigned long pixelclock;
        int data_lines;

        struct omap_dss_device output;
        struct drm_bridge bridge;
};

#define drm_bridge_to_dpi(bridge) container_of(bridge, struct dpi_data, bridge)

/* -----------------------------------------------------------------------------
 * Clock Handling and PLL
 */

static enum dss_clk_source dpi_get_clk_src_dra7xx(struct dpi_data *dpi,
                                                  enum omap_channel channel)
{
        /*
         * Possible clock sources:
         * LCD1: FCK/PLL1_1/HDMI_PLL
         * LCD2: FCK/PLL1_3/HDMI_PLL (DRA74x: PLL2_3)
         * LCD3: FCK/PLL1_3/HDMI_PLL (DRA74x: PLL2_1)
         */

        switch (channel) {
        case OMAP_DSS_CHANNEL_LCD:
        {
                if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_1))
                        return DSS_CLK_SRC_PLL1_1;
                break;
        }
        case OMAP_DSS_CHANNEL_LCD2:
        {
                if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_3))
                        return DSS_CLK_SRC_PLL1_3;
                if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL2_3))
                        return DSS_CLK_SRC_PLL2_3;
                break;
        }
        case OMAP_DSS_CHANNEL_LCD3:
        {
                if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL2_1))
                        return DSS_CLK_SRC_PLL2_1;
                if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_3))
                        return DSS_CLK_SRC_PLL1_3;
                break;
        }
        default:
                break;
        }

        return DSS_CLK_SRC_FCK;
}

static enum dss_clk_source dpi_get_clk_src(struct dpi_data *dpi)
{
        enum omap_channel channel = dpi->output.dispc_channel;

        /*
         * XXX we can't currently use DSI PLL for DPI with OMAP3, as the DSI PLL
         * would also be used for DISPC fclk. Meaning, when the DPI output is
         * disabled, DISPC clock will be disabled, and TV out will stop.
         */
        switch (dpi->dss_model) {
        case DSS_MODEL_OMAP2:
        case DSS_MODEL_OMAP3:
                return DSS_CLK_SRC_FCK;

        case DSS_MODEL_OMAP4:
                switch (channel) {
                case OMAP_DSS_CHANNEL_LCD:
                        return DSS_CLK_SRC_PLL1_1;
                case OMAP_DSS_CHANNEL_LCD2:
                        return DSS_CLK_SRC_PLL2_1;
                default:
                        return DSS_CLK_SRC_FCK;
                }

        case DSS_MODEL_OMAP5:
                switch (channel) {
                case OMAP_DSS_CHANNEL_LCD:
                        return DSS_CLK_SRC_PLL1_1;
                case OMAP_DSS_CHANNEL_LCD3:
                        return DSS_CLK_SRC_PLL2_1;
                case OMAP_DSS_CHANNEL_LCD2:
                default:
                        return DSS_CLK_SRC_FCK;
                }

        case DSS_MODEL_DRA7:
                return dpi_get_clk_src_dra7xx(dpi, channel);

        default:
                return DSS_CLK_SRC_FCK;
        }
}

struct dpi_clk_calc_ctx {
        struct dpi_data *dpi;
        unsigned int clkout_idx;

        /* inputs */

        unsigned long pck_min, pck_max;

        /* outputs */

        struct dss_pll_clock_info pll_cinfo;
        unsigned long fck;
        struct dispc_clock_info dispc_cinfo;
};

static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
                unsigned long pck, void *data)
{
        struct dpi_clk_calc_ctx *ctx = data;

        /*
         * Odd dividers give us uneven duty cycle, causing problem when level
         * shifted. So skip all odd dividers when the pixel clock is on the
         * higher side.
         */
        if (ctx->pck_min >= 100000000) {
                if (lckd > 1 && lckd % 2 != 0)
                        return false;

                if (pckd > 1 && pckd % 2 != 0)
                        return false;
        }

        ctx->dispc_cinfo.lck_div = lckd;
        ctx->dispc_cinfo.pck_div = pckd;
        ctx->dispc_cinfo.lck = lck;
        ctx->dispc_cinfo.pck = pck;

        return true;
}


static bool dpi_calc_hsdiv_cb(int m_dispc, unsigned long dispc,
                void *data)
{
        struct dpi_clk_calc_ctx *ctx = data;

        ctx->pll_cinfo.mX[ctx->clkout_idx] = m_dispc;
        ctx->pll_cinfo.clkout[ctx->clkout_idx] = dispc;

        return dispc_div_calc(ctx->dpi->dss->dispc, dispc,
                              ctx->pck_min, ctx->pck_max,
                              dpi_calc_dispc_cb, ctx);
}


static bool dpi_calc_pll_cb(int n, int m, unsigned long fint,
                unsigned long clkdco,
                void *data)
{
        struct dpi_clk_calc_ctx *ctx = data;

        ctx->pll_cinfo.n = n;
        ctx->pll_cinfo.m = m;
        ctx->pll_cinfo.fint = fint;
        ctx->pll_cinfo.clkdco = clkdco;

        return dss_pll_hsdiv_calc_a(ctx->dpi->pll, clkdco,
                ctx->pck_min, dss_get_max_fck_rate(ctx->dpi->dss),
                dpi_calc_hsdiv_cb, ctx);
}

static bool dpi_calc_dss_cb(unsigned long fck, void *data)
{
        struct dpi_clk_calc_ctx *ctx = data;

        ctx->fck = fck;

        return dispc_div_calc(ctx->dpi->dss->dispc, fck,
                              ctx->pck_min, ctx->pck_max,
                              dpi_calc_dispc_cb, ctx);
}

static bool dpi_pll_clk_calc(struct dpi_data *dpi, unsigned long pck,
                struct dpi_clk_calc_ctx *ctx)
{
        unsigned long clkin;

        memset(ctx, 0, sizeof(*ctx));
        ctx->dpi = dpi;
        ctx->clkout_idx = dss_pll_get_clkout_idx_for_src(dpi->clk_src);

        clkin = clk_get_rate(dpi->pll->clkin);

        if (dpi->pll->hw->type == DSS_PLL_TYPE_A) {
                unsigned long pll_min, pll_max;

                ctx->pck_min = pck - 1000;
                ctx->pck_max = pck + 1000;

                pll_min = 0;
                pll_max = 0;

                return dss_pll_calc_a(ctx->dpi->pll, clkin,
                                pll_min, pll_max,
                                dpi_calc_pll_cb, ctx);
        } else { /* DSS_PLL_TYPE_B */
                dss_pll_calc_b(dpi->pll, clkin, pck, &ctx->pll_cinfo);

                ctx->dispc_cinfo.lck_div = 1;
                ctx->dispc_cinfo.pck_div = 1;
                ctx->dispc_cinfo.lck = ctx->pll_cinfo.clkout[0];
                ctx->dispc_cinfo.pck = ctx->dispc_cinfo.lck;

                return true;
        }
}

static bool dpi_dss_clk_calc(struct dpi_data *dpi, unsigned long pck,
                             struct dpi_clk_calc_ctx *ctx)
{
        int i;

        /*
         * DSS fck gives us very few possibilities, so finding a good pixel
         * clock may not be possible. We try multiple times to find the clock,
         * each time widening the pixel clock range we look for, up to
         * +/- ~15MHz.
         */

        for (i = 0; i < 25; ++i) {
                bool ok;

                memset(ctx, 0, sizeof(*ctx));
                ctx->dpi = dpi;
                if (pck > 1000 * i * i * i)
                        ctx->pck_min = max(pck - 1000 * i * i * i, 0lu);
                else
                        ctx->pck_min = 0;
                ctx->pck_max = pck + 1000 * i * i * i;

                ok = dss_div_calc(dpi->dss, pck, ctx->pck_min,
                                  dpi_calc_dss_cb, ctx);
                if (ok)
                        return ok;
        }

        return false;
}



static int dpi_set_pll_clk(struct dpi_data *dpi, unsigned long pck_req)
{
        struct dpi_clk_calc_ctx ctx;
        int r;
        bool ok;

        ok = dpi_pll_clk_calc(dpi, pck_req, &ctx);
        if (!ok)
                return -EINVAL;

        r = dss_pll_set_config(dpi->pll, &ctx.pll_cinfo);
        if (r)
                return r;

        dss_select_lcd_clk_source(dpi->dss, dpi->output.dispc_channel,
                                  dpi->clk_src);

        dpi->mgr_config.clock_info = ctx.dispc_cinfo;

        return 0;
}

static int dpi_set_dispc_clk(struct dpi_data *dpi, unsigned long pck_req)
{
        struct dpi_clk_calc_ctx ctx;
        int r;
        bool ok;

        ok = dpi_dss_clk_calc(dpi, pck_req, &ctx);
        if (!ok)
                return -EINVAL;

        r = dss_set_fck_rate(dpi->dss, ctx.fck);
        if (r)
                return r;

        dpi->mgr_config.clock_info = ctx.dispc_cinfo;

        return 0;
}

static int dpi_set_mode(struct dpi_data *dpi)
{
        int r;

        if (dpi->pll)
                r = dpi_set_pll_clk(dpi, dpi->pixelclock);
        else
                r = dpi_set_dispc_clk(dpi, dpi->pixelclock);

        return r;
}

static void dpi_config_lcd_manager(struct dpi_data *dpi)
{
        dpi->mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;

        dpi->mgr_config.stallmode = false;
        dpi->mgr_config.fifohandcheck = false;

        dpi->mgr_config.video_port_width = dpi->data_lines;

        dpi->mgr_config.lcden_sig_polarity = 0;

        dss_mgr_set_lcd_config(&dpi->output, &dpi->mgr_config);
}

static int dpi_clock_update(struct dpi_data *dpi, unsigned long *clock)
{
        int lck_div, pck_div;
        unsigned long fck;
        struct dpi_clk_calc_ctx ctx;

        if (dpi->pll) {
                if (!dpi_pll_clk_calc(dpi, *clock, &ctx))
                        return -EINVAL;

                fck = ctx.pll_cinfo.clkout[ctx.clkout_idx];
        } else {
                if (!dpi_dss_clk_calc(dpi, *clock, &ctx))
                        return -EINVAL;

                fck = ctx.fck;
        }

        lck_div = ctx.dispc_cinfo.lck_div;
        pck_div = ctx.dispc_cinfo.pck_div;

        *clock = fck / lck_div / pck_div;

        return 0;
}

static int dpi_verify_pll(struct dss_pll *pll)
{
        int r;

        /* do initial setup with the PLL to see if it is operational */

        r = dss_pll_enable(pll);
        if (r)
                return r;

        dss_pll_disable(pll);

        return 0;
}

static void dpi_init_pll(struct dpi_data *dpi)
{
        struct dss_pll *pll;

        if (dpi->pll)
                return;

        dpi->clk_src = dpi_get_clk_src(dpi);

        pll = dss_pll_find_by_src(dpi->dss, dpi->clk_src);
        if (!pll)
                return;

        if (dpi_verify_pll(pll)) {
                DSSWARN("PLL not operational\n");
                return;
        }

        dpi->pll = pll;
}

/* -----------------------------------------------------------------------------
 * DRM Bridge Operations
 */

static int dpi_bridge_attach(struct drm_bridge *bridge,
                             enum drm_bridge_attach_flags flags)
{
        struct dpi_data *dpi = drm_bridge_to_dpi(bridge);

        if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
                return -EINVAL;

        dpi_init_pll(dpi);

        return drm_bridge_attach(bridge->encoder, dpi->output.next_bridge,
                                 bridge, flags);
}

static enum drm_mode_status
dpi_bridge_mode_valid(struct drm_bridge *bridge,
                       const struct drm_display_info *info,
                       const struct drm_display_mode *mode)
{
        struct dpi_data *dpi = drm_bridge_to_dpi(bridge);
        unsigned long clock = mode->clock * 1000;
        int ret;

        if (mode->hdisplay % 8 != 0)
                return MODE_BAD_WIDTH;

        if (mode->clock == 0)
                return MODE_NOCLOCK;

        ret = dpi_clock_update(dpi, &clock);
        if (ret < 0)
                return MODE_CLOCK_RANGE;

        return MODE_OK;
}

static bool dpi_bridge_mode_fixup(struct drm_bridge *bridge,
                                   const struct drm_display_mode *mode,
                                   struct drm_display_mode *adjusted_mode)
{
        struct dpi_data *dpi = drm_bridge_to_dpi(bridge);
        unsigned long clock = mode->clock * 1000;
        int ret;

        ret = dpi_clock_update(dpi, &clock);
        if (ret < 0)
                return false;

        adjusted_mode->clock = clock / 1000;

        return true;
}

static void dpi_bridge_mode_set(struct drm_bridge *bridge,
                                 const struct drm_display_mode *mode,
                                 const struct drm_display_mode *adjusted_mode)
{
        struct dpi_data *dpi = drm_bridge_to_dpi(bridge);

        dpi->pixelclock = adjusted_mode->clock * 1000;
}

static void dpi_bridge_enable(struct drm_bridge *bridge)
{
        struct dpi_data *dpi = drm_bridge_to_dpi(bridge);
        int r;

        if (dpi->vdds_dsi_reg) {
                r = regulator_enable(dpi->vdds_dsi_reg);
                if (r)
                        return;
        }

        r = dispc_runtime_get(dpi->dss->dispc);
        if (r)
                goto err_get_dispc;

        r = dss_dpi_select_source(dpi->dss, dpi->id, dpi->output.dispc_channel);
        if (r)
                goto err_src_sel;

        if (dpi->pll) {
                r = dss_pll_enable(dpi->pll);
                if (r)
                        goto err_pll_init;
        }

        r = dpi_set_mode(dpi);
        if (r)
                goto err_set_mode;

        dpi_config_lcd_manager(dpi);

        mdelay(2);

        r = dss_mgr_enable(&dpi->output);
        if (r)
                goto err_mgr_enable;

        return;

err_mgr_enable:
err_set_mode:
        if (dpi->pll)
                dss_pll_disable(dpi->pll);
err_pll_init:
err_src_sel:
        dispc_runtime_put(dpi->dss->dispc);
err_get_dispc:
        if (dpi->vdds_dsi_reg)
                regulator_disable(dpi->vdds_dsi_reg);
}

static void dpi_bridge_disable(struct drm_bridge *bridge)
{
        struct dpi_data *dpi = drm_bridge_to_dpi(bridge);

        dss_mgr_disable(&dpi->output);

        if (dpi->pll) {
                dss_select_lcd_clk_source(dpi->dss, dpi->output.dispc_channel,
                                          DSS_CLK_SRC_FCK);
                dss_pll_disable(dpi->pll);
        }

        dispc_runtime_put(dpi->dss->dispc);

        if (dpi->vdds_dsi_reg)
                regulator_disable(dpi->vdds_dsi_reg);
}

static const struct drm_bridge_funcs dpi_bridge_funcs = {
        .attach = dpi_bridge_attach,
        .mode_valid = dpi_bridge_mode_valid,
        .mode_fixup = dpi_bridge_mode_fixup,
        .mode_set = dpi_bridge_mode_set,
        .enable = dpi_bridge_enable,
        .disable = dpi_bridge_disable,
};

static void dpi_bridge_init(struct dpi_data *dpi)
{
        dpi->bridge.funcs = &dpi_bridge_funcs;
        dpi->bridge.of_node = dpi->pdev->dev.of_node;
        dpi->bridge.type = DRM_MODE_CONNECTOR_DPI;

        drm_bridge_add(&dpi->bridge);
}

static void dpi_bridge_cleanup(struct dpi_data *dpi)
{
        drm_bridge_remove(&dpi->bridge);
}

/* -----------------------------------------------------------------------------
 * Initialisation and Cleanup
 */

/*
 * Return a hardcoded channel for the DPI output. This should work for
 * current use cases, but this can be later expanded to either resolve
 * the channel in some more dynamic manner, or get the channel as a user
 * parameter.
 */
static enum omap_channel dpi_get_channel(struct dpi_data *dpi)
{
        switch (dpi->dss_model) {
        case DSS_MODEL_OMAP2:
        case DSS_MODEL_OMAP3:
                return OMAP_DSS_CHANNEL_LCD;

        case DSS_MODEL_DRA7:
                switch (dpi->id) {
                case 2:
                        return OMAP_DSS_CHANNEL_LCD3;
                case 1:
                        return OMAP_DSS_CHANNEL_LCD2;
                case 0:
                default:
                        return OMAP_DSS_CHANNEL_LCD;
                }

        case DSS_MODEL_OMAP4:
                return OMAP_DSS_CHANNEL_LCD2;

        case DSS_MODEL_OMAP5:
                return OMAP_DSS_CHANNEL_LCD3;

        default:
                DSSWARN("unsupported DSS version\n");
                return OMAP_DSS_CHANNEL_LCD;
        }
}

static int dpi_init_output_port(struct dpi_data *dpi, struct device_node *port)
{
        struct omap_dss_device *out = &dpi->output;
        u32 port_num = 0;
        int r;

        dpi_bridge_init(dpi);

        of_property_read_u32(port, "reg", &port_num);
        dpi->id = port_num <= 2 ? port_num : 0;

        switch (port_num) {
        case 2:
                out->name = "dpi.2";
                break;
        case 1:
                out->name = "dpi.1";
                break;
        case 0:
        default:
                out->name = "dpi.0";
                break;
        }

        out->dev = &dpi->pdev->dev;
        out->id = OMAP_DSS_OUTPUT_DPI;
        out->type = OMAP_DISPLAY_TYPE_DPI;
        out->dispc_channel = dpi_get_channel(dpi);
        out->of_port = port_num;

        r = omapdss_device_init_output(out, &dpi->bridge);
        if (r < 0) {
                dpi_bridge_cleanup(dpi);
                return r;
        }

        omapdss_device_register(out);

        return 0;
}

static void dpi_uninit_output_port(struct device_node *port)
{
        struct dpi_data *dpi = port->data;
        struct omap_dss_device *out = &dpi->output;

        omapdss_device_unregister(out);
        omapdss_device_cleanup_output(out);

        dpi_bridge_cleanup(dpi);
}

/* -----------------------------------------------------------------------------
 * Initialisation and Cleanup
 */

static const struct soc_device_attribute dpi_soc_devices[] = {
        { .machine = "OMAP3[456]*" },
        { .machine = "[AD]M37*" },
        { /* sentinel */ }
};

static int dpi_init_regulator(struct dpi_data *dpi)
{
        struct regulator *vdds_dsi;

        /*
         * The DPI uses the DSI VDDS on OMAP34xx, OMAP35xx, OMAP36xx, AM37xx and
         * DM37xx only.
         */
        if (!soc_device_match(dpi_soc_devices))
                return 0;

        vdds_dsi = devm_regulator_get(&dpi->pdev->dev, "vdds_dsi");
        if (IS_ERR(vdds_dsi)) {
                if (PTR_ERR(vdds_dsi) != -EPROBE_DEFER)
                        DSSERR("can't get VDDS_DSI regulator\n");
                return PTR_ERR(vdds_dsi);
        }

        dpi->vdds_dsi_reg = vdds_dsi;

        return 0;
}

int dpi_init_port(struct dss_device *dss, struct platform_device *pdev,
                  struct device_node *port, enum dss_model dss_model)
{
        struct dpi_data *dpi;
        struct device_node *ep;
        u32 datalines;
        int r;

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

        ep = of_get_next_child(port, NULL);
        if (!ep)
                return 0;

        r = of_property_read_u32(ep, "data-lines", &datalines);
        of_node_put(ep);
        if (r) {
                DSSERR("failed to parse datalines\n");
                return r;
        }

        dpi->data_lines = datalines;

        dpi->pdev = pdev;
        dpi->dss_model = dss_model;
        dpi->dss = dss;
        port->data = dpi;

        r = dpi_init_regulator(dpi);
        if (r)
                return r;

        return dpi_init_output_port(dpi, port);
}

void dpi_uninit_port(struct device_node *port)
{
        struct dpi_data *dpi = port->data;

        if (!dpi)
                return;

        dpi_uninit_output_port(port);
}