/*
 * linux/drivers/video/omap2/dss/dpi.c
 *
 * Copyright (C) 2009 Nokia Corporation
 * Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
 *
 * Some code and ideas taken from drivers/video/omap/ driver
 * by Imre Deak.
 *
 * 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 "DPI"

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

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

struct dpi_data {
        struct platform_device *pdev;
        enum dss_model dss_model;

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

        struct mutex lock;

        struct videomode vm;
        struct dss_lcd_mgr_config mgr_config;
        int data_lines;

        struct omap_dss_device output;

        bool port_initialized;
};

static struct dpi_data *dpi_get_data_from_dssdev(struct omap_dss_device *dssdev)
{
        return container_of(dssdev, struct dpi_data, output);
}

static enum dss_clk_source dpi_get_clk_src_dra7xx(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(DSS_CLK_SRC_PLL1_1))
                        return DSS_CLK_SRC_PLL1_1;
                break;
        }
        case OMAP_DSS_CHANNEL_LCD2:
        {
                if (dss_pll_find_by_src(DSS_CLK_SRC_PLL1_3))
                        return DSS_CLK_SRC_PLL1_3;
                if (dss_pll_find_by_src(DSS_CLK_SRC_PLL2_3))
                        return DSS_CLK_SRC_PLL2_3;
                break;
        }
        case OMAP_DSS_CHANNEL_LCD3:
        {
                if (dss_pll_find_by_src(DSS_CLK_SRC_PLL2_1))
                        return DSS_CLK_SRC_PLL2_1;
                if (dss_pll_find_by_src(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(channel);

        default:
                return DSS_CLK_SRC_FCK;
        }
}

struct dpi_clk_calc_ctx {
        struct dss_pll *pll;
        unsigned 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(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->pll, clkdco,
                ctx->pck_min, dss_get_max_fck_rate(),
                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(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->pll = dpi->pll;
        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->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(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));
                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(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, enum omap_channel channel,
                unsigned long pck_req, unsigned long *fck, int *lck_div,
                int *pck_div)
{
        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(channel, dpi->clk_src);

        dpi->mgr_config.clock_info = ctx.dispc_cinfo;

        *fck = ctx.pll_cinfo.clkout[ctx.clkout_idx];
        *lck_div = ctx.dispc_cinfo.lck_div;
        *pck_div = ctx.dispc_cinfo.pck_div;

        return 0;
}

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

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

        r = dss_set_fck_rate(ctx.fck);
        if (r)
                return r;

        dpi->mgr_config.clock_info = ctx.dispc_cinfo;

        *fck = ctx.fck;
        *lck_div = ctx.dispc_cinfo.lck_div;
        *pck_div = ctx.dispc_cinfo.pck_div;

        return 0;
}

static int dpi_set_mode(struct dpi_data *dpi)
{
        struct omap_dss_device *out = &dpi->output;
        enum omap_channel channel = out->dispc_channel;
        struct videomode *vm = &dpi->vm;
        int lck_div = 0, pck_div = 0;
        unsigned long fck = 0;
        unsigned long pck;
        int r = 0;

        if (dpi->pll)
                r = dpi_set_pll_clk(dpi, channel, vm->pixelclock, &fck,
                                &lck_div, &pck_div);
        else
                r = dpi_set_dispc_clk(dpi, vm->pixelclock, &fck,
                                &lck_div, &pck_div);
        if (r)
                return r;

        pck = fck / lck_div / pck_div;

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

                vm->pixelclock = pck;
        }

        dss_mgr_set_timings(channel, vm);

        return 0;
}

static void dpi_config_lcd_manager(struct dpi_data *dpi)
{
        struct omap_dss_device *out = &dpi->output;
        enum omap_channel channel = out->dispc_channel;

        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(channel, &dpi->mgr_config);
}

static int dpi_display_enable(struct omap_dss_device *dssdev)
{
        struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
        struct omap_dss_device *out = &dpi->output;
        enum omap_channel channel = out->dispc_channel;
        int r;

        mutex_lock(&dpi->lock);

        if (!out->dispc_channel_connected) {
                DSSERR("failed to enable display: no output/manager\n");
                r = -ENODEV;
                goto err_no_out_mgr;
        }

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

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

        r = dss_dpi_select_source(out->port_num, 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(channel);
        if (r)
                goto err_mgr_enable;

        mutex_unlock(&dpi->lock);

        return 0;

err_mgr_enable:
err_set_mode:
        if (dpi->pll)
                dss_pll_disable(dpi->pll);
err_pll_init:
err_src_sel:
        dispc_runtime_put();
err_get_dispc:
        if (dpi->vdds_dsi_reg)
                regulator_disable(dpi->vdds_dsi_reg);
err_reg_enable:
err_no_out_mgr:
        mutex_unlock(&dpi->lock);
        return r;
}

static void dpi_display_disable(struct omap_dss_device *dssdev)
{
        struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
        enum omap_channel channel = dpi->output.dispc_channel;

        mutex_lock(&dpi->lock);

        dss_mgr_disable(channel);

        if (dpi->pll) {
                dss_select_lcd_clk_source(channel, DSS_CLK_SRC_FCK);
                dss_pll_disable(dpi->pll);
        }

        dispc_runtime_put();

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

        mutex_unlock(&dpi->lock);
}

static void dpi_set_timings(struct omap_dss_device *dssdev,
                            struct videomode *vm)
{
        struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);

        DSSDBG("dpi_set_timings\n");

        mutex_lock(&dpi->lock);

        dpi->vm = *vm;

        mutex_unlock(&dpi->lock);
}

static void dpi_get_timings(struct omap_dss_device *dssdev,
                            struct videomode *vm)
{
        struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);

        mutex_lock(&dpi->lock);

        *vm = dpi->vm;

        mutex_unlock(&dpi->lock);
}

static int dpi_check_timings(struct omap_dss_device *dssdev,
                             struct videomode *vm)
{
        struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
        enum omap_channel channel = dpi->output.dispc_channel;
        int lck_div, pck_div;
        unsigned long fck;
        unsigned long pck;
        struct dpi_clk_calc_ctx ctx;
        bool ok;

        if (vm->hactive % 8 != 0)
                return -EINVAL;

        if (!dispc_mgr_timings_ok(channel, vm))
                return -EINVAL;

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

        if (dpi->pll) {
                ok = dpi_pll_clk_calc(dpi, vm->pixelclock, &ctx);
                if (!ok)
                        return -EINVAL;

                fck = ctx.pll_cinfo.clkout[ctx.clkout_idx];
        } else {
                ok = dpi_dss_clk_calc(vm->pixelclock, &ctx);
                if (!ok)
                        return -EINVAL;

                fck = ctx.fck;
        }

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

        pck = fck / lck_div / pck_div;

        vm->pixelclock = pck;

        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 const struct soc_device_attribute dpi_soc_devices[] = {
        { .family = "OMAP3[456]*" },
        { .family = "[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;

        if (dpi->vdds_dsi_reg)
                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;
}

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->clk_src);
        if (!pll)
                return;

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

        dpi->pll = pll;
}

/*
 * 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, int port_num)
{
        switch (dpi->dss_model) {
        case DSS_MODEL_OMAP2:
        case DSS_MODEL_OMAP3:
                return OMAP_DSS_CHANNEL_LCD;

        case DSS_MODEL_DRA7:
                switch (port_num) {
                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_connect(struct omap_dss_device *dssdev,
                struct omap_dss_device *dst)
{
        struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
        enum omap_channel channel = dpi->output.dispc_channel;
        int r;

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

        dpi_init_pll(dpi);

        r = dss_mgr_connect(channel, 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(channel, dssdev);
                return r;
        }

        return 0;
}

static void dpi_disconnect(struct omap_dss_device *dssdev,
                struct omap_dss_device *dst)
{
        struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
        enum omap_channel channel = dpi->output.dispc_channel;

        WARN_ON(dst != dssdev->dst);

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

        omapdss_output_unset_device(dssdev);

        dss_mgr_disconnect(channel, dssdev);
}

static const struct omapdss_dpi_ops dpi_ops = {
        .connect = dpi_connect,
        .disconnect = dpi_disconnect,

        .enable = dpi_display_enable,
        .disable = dpi_display_disable,

        .check_timings = dpi_check_timings,
        .set_timings = dpi_set_timings,
        .get_timings = dpi_get_timings,
};

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

        r = of_property_read_u32(port, "reg", &port_num);
        if (r)
                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->output_type = OMAP_DISPLAY_TYPE_DPI;
        out->dispc_channel = dpi_get_channel(dpi, port_num);
        out->port_num = port_num;
        out->ops.dpi = &dpi_ops;
        out->owner = THIS_MODULE;

        omapdss_register_output(out);
}

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

        omapdss_unregister_output(out);
}

int dpi_init_port(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);
        if (r) {
                DSSERR("failed to parse datalines\n");
                goto err_datalines;
        }

        dpi->data_lines = datalines;

        of_node_put(ep);

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

        mutex_init(&dpi->lock);

        dpi_init_output_port(dpi, port);

        dpi->port_initialized = true;

        return 0;

err_datalines:
        of_node_put(ep);

        return r;
}

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

        if (!dpi->port_initialized)
                return;

        dpi_uninit_output_port(port);
}