/*
 * linux/drivers/video/omap2/dss/sdi.c
 *
 * Copyright (C) 2009 Nokia Corporation
 * Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#define DSS_SUBSYS_NAME "SDI"

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

#include <video/omapdss.h>
#include "dss.h"

static struct {
        struct platform_device *pdev;

        bool update_enabled;
        struct regulator *vdds_sdi_reg;

        struct dss_lcd_mgr_config mgr_config;
        struct omap_video_timings timings;
        int datapairs;

        struct omap_dss_device output;

        bool port_initialized;
} sdi;

struct sdi_clk_calc_ctx {
        unsigned long pck_min, pck_max;

        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 sdi_clk_calc_ctx *ctx = data;

        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_dss_cb(unsigned long fck, void *data)
{
        struct sdi_clk_calc_ctx *ctx = data;

        ctx->fck = fck;

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

static int sdi_calc_clock_div(unsigned long pclk,
                unsigned long *fck,
                struct dispc_clock_info *dispc_cinfo)
{
        int i;
        struct sdi_clk_calc_ctx ctx;

        /*
         * DSS fclk 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
         * +/- 1MHz.
         */

        for (i = 0; i < 10; ++i) {
                bool ok;

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

                ok = dss_div_calc(pclk, ctx.pck_min, dpi_calc_dss_cb, &ctx);
                if (ok) {
                        *fck = ctx.fck;
                        *dispc_cinfo = ctx.dispc_cinfo;
                        return 0;
                }
        }

        return -EINVAL;
}

static void sdi_config_lcd_manager(struct omap_dss_device *dssdev)
{
        struct omap_overlay_manager *mgr = sdi.output.manager;

        sdi.mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;

        sdi.mgr_config.stallmode = false;
        sdi.mgr_config.fifohandcheck = false;

        sdi.mgr_config.video_port_width = 24;
        sdi.mgr_config.lcden_sig_polarity = 1;

        dss_mgr_set_lcd_config(mgr, &sdi.mgr_config);
}

static int sdi_display_enable(struct omap_dss_device *dssdev)
{
        struct omap_dss_device *out = &sdi.output;
        struct omap_video_timings *t = &sdi.timings;
        unsigned long fck;
        struct dispc_clock_info dispc_cinfo;
        unsigned long pck;
        int r;

        if (out == NULL || out->manager == NULL) {
                DSSERR("failed to enable display: no output/manager\n");
                return -ENODEV;
        }

        r = regulator_enable(sdi.vdds_sdi_reg);
        if (r)
                goto err_reg_enable;

        r = dispc_runtime_get();
        if (r)
                goto err_get_dispc;

        /* 15.5.9.1.2 */
        t->data_pclk_edge = OMAPDSS_DRIVE_SIG_RISING_EDGE;
        t->sync_pclk_edge = OMAPDSS_DRIVE_SIG_RISING_EDGE;

        r = sdi_calc_clock_div(t->pixelclock, &fck, &dispc_cinfo);
        if (r)
                goto err_calc_clock_div;

        sdi.mgr_config.clock_info = dispc_cinfo;

        pck = fck / dispc_cinfo.lck_div / dispc_cinfo.pck_div;

        if (pck != t->pixelclock) {
                DSSWARN("Could not find exact pixel clock. Requested %d Hz, got %lu Hz\n",
                        t->pixelclock, pck);

                t->pixelclock = pck;
        }


        dss_mgr_set_timings(out->manager, t);

        r = dss_set_fck_rate(fck);
        if (r)
                goto err_set_dss_clock_div;

        sdi_config_lcd_manager(dssdev);

        /*
         * LCLK and PCLK divisors are located in shadow registers, and we
         * normally write them to DISPC registers when enabling the output.
         * However, SDI uses pck-free as source clock for its PLL, and pck-free
         * is affected by the divisors. And as we need the PLL before enabling
         * the output, we need to write the divisors early.
         *
         * It seems just writing to the DISPC register is enough, and we don't
         * need to care about the shadow register mechanism for pck-free. The
         * exact reason for this is unknown.
         */
        dispc_mgr_set_clock_div(out->manager->id, &sdi.mgr_config.clock_info);

        dss_sdi_init(sdi.datapairs);
        r = dss_sdi_enable();
        if (r)
                goto err_sdi_enable;
        mdelay(2);

        r = dss_mgr_enable(out->manager);
        if (r)
                goto err_mgr_enable;

        return 0;

err_mgr_enable:
        dss_sdi_disable();
err_sdi_enable:
err_set_dss_clock_div:
err_calc_clock_div:
        dispc_runtime_put();
err_get_dispc:
        regulator_disable(sdi.vdds_sdi_reg);
err_reg_enable:
        return r;
}

static void sdi_display_disable(struct omap_dss_device *dssdev)
{
        struct omap_overlay_manager *mgr = sdi.output.manager;

        dss_mgr_disable(mgr);

        dss_sdi_disable();

        dispc_runtime_put();

        regulator_disable(sdi.vdds_sdi_reg);
}

static void sdi_set_timings(struct omap_dss_device *dssdev,
                struct omap_video_timings *timings)
{
        sdi.timings = *timings;
}

static void sdi_get_timings(struct omap_dss_device *dssdev,
                struct omap_video_timings *timings)
{
        *timings = sdi.timings;
}

static int sdi_check_timings(struct omap_dss_device *dssdev,
                        struct omap_video_timings *timings)
{
        struct omap_overlay_manager *mgr = sdi.output.manager;

        if (mgr && !dispc_mgr_timings_ok(mgr->id, timings))
                return -EINVAL;

        if (timings->pixelclock == 0)
                return -EINVAL;

        return 0;
}

static void sdi_set_datapairs(struct omap_dss_device *dssdev, int datapairs)
{
        sdi.datapairs = datapairs;
}

static int sdi_init_regulator(void)
{
        struct regulator *vdds_sdi;

        if (sdi.vdds_sdi_reg)
                return 0;

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

        sdi.vdds_sdi_reg = vdds_sdi;

        return 0;
}

static int sdi_connect(struct omap_dss_device *dssdev,
                struct omap_dss_device *dst)
{
        struct omap_overlay_manager *mgr;
        int r;

        r = sdi_init_regulator();
        if (r)
                return r;

        mgr = omap_dss_get_overlay_manager(dssdev->dispc_channel);
        if (!mgr)
                return -ENODEV;

        r = dss_mgr_connect(mgr, dssdev);
        if (r)
                return r;

        r = omapdss_output_set_device(dssdev, dst);
        if (r) {
                DSSERR("failed to connect output to new device: %s\n",
                                dst->name);
                dss_mgr_disconnect(mgr, dssdev);
                return r;
        }

        return 0;
}

static void sdi_disconnect(struct omap_dss_device *dssdev,
                struct omap_dss_device *dst)
{
        WARN_ON(dst != dssdev->dst);

        if (dst != dssdev->dst)
                return;

        omapdss_output_unset_device(dssdev);

        if (dssdev->manager)
                dss_mgr_disconnect(dssdev->manager, dssdev);
}

static const struct omapdss_sdi_ops sdi_ops = {
        .connect = sdi_connect,
        .disconnect = sdi_disconnect,

        .enable = sdi_display_enable,
        .disable = sdi_display_disable,

        .check_timings = sdi_check_timings,
        .set_timings = sdi_set_timings,
        .get_timings = sdi_get_timings,

        .set_datapairs = sdi_set_datapairs,
};

static void sdi_init_output(struct platform_device *pdev)
{
        struct omap_dss_device *out = &sdi.output;

        out->dev = &pdev->dev;
        out->id = OMAP_DSS_OUTPUT_SDI;
        out->output_type = OMAP_DISPLAY_TYPE_SDI;
        out->name = "sdi.0";
        out->dispc_channel = OMAP_DSS_CHANNEL_LCD;
        out->ops.sdi = &sdi_ops;
        out->owner = THIS_MODULE;

        omapdss_register_output(out);
}

static void __exit sdi_uninit_output(struct platform_device *pdev)
{
        struct omap_dss_device *out = &sdi.output;

        omapdss_unregister_output(out);
}

static int omap_sdi_probe(struct platform_device *pdev)
{
        sdi.pdev = pdev;

        sdi_init_output(pdev);

        return 0;
}

static int __exit omap_sdi_remove(struct platform_device *pdev)
{
        sdi_uninit_output(pdev);

        return 0;
}

static struct platform_driver omap_sdi_driver = {
        .probe          = omap_sdi_probe,
        .remove         = __exit_p(omap_sdi_remove),
        .driver         = {
                .name   = "omapdss_sdi",
                .owner  = THIS_MODULE,
                .suppress_bind_attrs = true,
        },
};

int __init sdi_init_platform_driver(void)
{
        return platform_driver_register(&omap_sdi_driver);
}

void __exit sdi_uninit_platform_driver(void)
{
        platform_driver_unregister(&omap_sdi_driver);
}

int __init sdi_init_port(struct platform_device *pdev, struct device_node *port)
{
        struct device_node *ep;
        u32 datapairs;
        int r;

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

        r = of_property_read_u32(ep, "datapairs", &datapairs);
        if (r) {
                DSSERR("failed to parse datapairs\n");
                goto err_datapairs;
        }

        sdi.datapairs = datapairs;

        of_node_put(ep);

        sdi.pdev = pdev;

        sdi_init_output(pdev);

        sdi.port_initialized = true;

        return 0;

err_datapairs:
        of_node_put(ep);

        return r;
}

void __exit sdi_uninit_port(void)
{
        if (!sdi.port_initialized)
                return;

        sdi_uninit_output(sdi.pdev);
}