/*
 * Copyright (c) 2016, The Linux Foundation. All rights reserved.
 *
 * 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/>.
 */

#include <linux/irqdomain.h>
#include <linux/irq.h>

#include "msm_drv.h"
#include "mdp5_kms.h"

#define to_mdp5_mdss(x) container_of(x, struct mdp5_mdss, base)

struct mdp5_mdss {
        struct msm_mdss base;

        void __iomem *mmio, *vbif;

        struct regulator *vdd;

        struct clk *ahb_clk;
        struct clk *axi_clk;
        struct clk *vsync_clk;

        struct {
                volatile unsigned long enabled_mask;
                struct irq_domain *domain;
        } irqcontroller;
};

static inline void mdss_write(struct mdp5_mdss *mdp5_mdss, u32 reg, u32 data)
{
        msm_writel(data, mdp5_mdss->mmio + reg);
}

static inline u32 mdss_read(struct mdp5_mdss *mdp5_mdss, u32 reg)
{
        return msm_readl(mdp5_mdss->mmio + reg);
}

static irqreturn_t mdss_irq(int irq, void *arg)
{
        struct mdp5_mdss *mdp5_mdss = arg;
        u32 intr;

        intr = mdss_read(mdp5_mdss, REG_MDSS_HW_INTR_STATUS);

        VERB("intr=%08x", intr);

        while (intr) {
                irq_hw_number_t hwirq = fls(intr) - 1;

                generic_handle_irq(irq_find_mapping(
                                mdp5_mdss->irqcontroller.domain, hwirq));
                intr &= ~(1 << hwirq);
        }

        return IRQ_HANDLED;
}

/*
 * interrupt-controller implementation, so sub-blocks (MDP/HDMI/eDP/DSI/etc)
 * can register to get their irq's delivered
 */

#define VALID_IRQS  (MDSS_HW_INTR_STATUS_INTR_MDP | \
                MDSS_HW_INTR_STATUS_INTR_DSI0 | \
                MDSS_HW_INTR_STATUS_INTR_DSI1 | \
                MDSS_HW_INTR_STATUS_INTR_HDMI | \
                MDSS_HW_INTR_STATUS_INTR_EDP)

static void mdss_hw_mask_irq(struct irq_data *irqd)
{
        struct mdp5_mdss *mdp5_mdss = irq_data_get_irq_chip_data(irqd);

        smp_mb__before_atomic();
        clear_bit(irqd->hwirq, &mdp5_mdss->irqcontroller.enabled_mask);
        smp_mb__after_atomic();
}

static void mdss_hw_unmask_irq(struct irq_data *irqd)
{
        struct mdp5_mdss *mdp5_mdss = irq_data_get_irq_chip_data(irqd);

        smp_mb__before_atomic();
        set_bit(irqd->hwirq, &mdp5_mdss->irqcontroller.enabled_mask);
        smp_mb__after_atomic();
}

static struct irq_chip mdss_hw_irq_chip = {
        .name           = "mdss",
        .irq_mask       = mdss_hw_mask_irq,
        .irq_unmask     = mdss_hw_unmask_irq,
};

static int mdss_hw_irqdomain_map(struct irq_domain *d, unsigned int irq,
                                 irq_hw_number_t hwirq)
{
        struct mdp5_mdss *mdp5_mdss = d->host_data;

        if (!(VALID_IRQS & (1 << hwirq)))
                return -EPERM;

        irq_set_chip_and_handler(irq, &mdss_hw_irq_chip, handle_level_irq);
        irq_set_chip_data(irq, mdp5_mdss);

        return 0;
}

static const struct irq_domain_ops mdss_hw_irqdomain_ops = {
        .map = mdss_hw_irqdomain_map,
        .xlate = irq_domain_xlate_onecell,
};


static int mdss_irq_domain_init(struct mdp5_mdss *mdp5_mdss)
{
        struct device *dev = mdp5_mdss->base.dev->dev;
        struct irq_domain *d;

        d = irq_domain_add_linear(dev->of_node, 32, &mdss_hw_irqdomain_ops,
                                  mdp5_mdss);
        if (!d) {
                dev_err(dev, "mdss irq domain add failed\n");
                return -ENXIO;
        }

        mdp5_mdss->irqcontroller.enabled_mask = 0;
        mdp5_mdss->irqcontroller.domain = d;

        return 0;
}

static int mdp5_mdss_enable(struct msm_mdss *mdss)
{
        struct mdp5_mdss *mdp5_mdss = to_mdp5_mdss(mdss);
        DBG("");

        clk_prepare_enable(mdp5_mdss->ahb_clk);
        if (mdp5_mdss->axi_clk)
                clk_prepare_enable(mdp5_mdss->axi_clk);
        if (mdp5_mdss->vsync_clk)
                clk_prepare_enable(mdp5_mdss->vsync_clk);

        return 0;
}

static int mdp5_mdss_disable(struct msm_mdss *mdss)
{
        struct mdp5_mdss *mdp5_mdss = to_mdp5_mdss(mdss);
        DBG("");

        if (mdp5_mdss->vsync_clk)
                clk_disable_unprepare(mdp5_mdss->vsync_clk);
        if (mdp5_mdss->axi_clk)
                clk_disable_unprepare(mdp5_mdss->axi_clk);
        clk_disable_unprepare(mdp5_mdss->ahb_clk);

        return 0;
}

static int msm_mdss_get_clocks(struct mdp5_mdss *mdp5_mdss)
{
        struct platform_device *pdev =
                        to_platform_device(mdp5_mdss->base.dev->dev);

        mdp5_mdss->ahb_clk = msm_clk_get(pdev, "iface");
        if (IS_ERR(mdp5_mdss->ahb_clk))
                mdp5_mdss->ahb_clk = NULL;

        mdp5_mdss->axi_clk = msm_clk_get(pdev, "bus");
        if (IS_ERR(mdp5_mdss->axi_clk))
                mdp5_mdss->axi_clk = NULL;

        mdp5_mdss->vsync_clk = msm_clk_get(pdev, "vsync");
        if (IS_ERR(mdp5_mdss->vsync_clk))
                mdp5_mdss->vsync_clk = NULL;

        return 0;
}

static void mdp5_mdss_destroy(struct drm_device *dev)
{
        struct msm_drm_private *priv = dev->dev_private;
        struct mdp5_mdss *mdp5_mdss = to_mdp5_mdss(priv->mdss);

        if (!mdp5_mdss)
                return;

        irq_domain_remove(mdp5_mdss->irqcontroller.domain);
        mdp5_mdss->irqcontroller.domain = NULL;

        regulator_disable(mdp5_mdss->vdd);

        pm_runtime_disable(dev->dev);
}

static const struct msm_mdss_funcs mdss_funcs = {
        .enable = mdp5_mdss_enable,
        .disable = mdp5_mdss_disable,
        .destroy = mdp5_mdss_destroy,
};

int mdp5_mdss_init(struct drm_device *dev)
{
        struct platform_device *pdev = to_platform_device(dev->dev);
        struct msm_drm_private *priv = dev->dev_private;
        struct mdp5_mdss *mdp5_mdss;
        int ret;

        DBG("");

        if (!of_device_is_compatible(dev->dev->of_node, "qcom,mdss"))
                return 0;

        mdp5_mdss = devm_kzalloc(dev->dev, sizeof(*mdp5_mdss), GFP_KERNEL);
        if (!mdp5_mdss) {
                ret = -ENOMEM;
                goto fail;
        }

        mdp5_mdss->base.dev = dev;

        mdp5_mdss->mmio = msm_ioremap(pdev, "mdss_phys", "MDSS");
        if (IS_ERR(mdp5_mdss->mmio)) {
                ret = PTR_ERR(mdp5_mdss->mmio);
                goto fail;
        }

        mdp5_mdss->vbif = msm_ioremap(pdev, "vbif_phys", "VBIF");
        if (IS_ERR(mdp5_mdss->vbif)) {
                ret = PTR_ERR(mdp5_mdss->vbif);
                goto fail;
        }

        ret = msm_mdss_get_clocks(mdp5_mdss);
        if (ret) {
                dev_err(dev->dev, "failed to get clocks: %d\n", ret);
                goto fail;
        }

        /* Regulator to enable GDSCs in downstream kernels */
        mdp5_mdss->vdd = devm_regulator_get(dev->dev, "vdd");
        if (IS_ERR(mdp5_mdss->vdd)) {
                ret = PTR_ERR(mdp5_mdss->vdd);
                goto fail;
        }

        ret = regulator_enable(mdp5_mdss->vdd);
        if (ret) {
                dev_err(dev->dev, "failed to enable regulator vdd: %d\n",
                        ret);
                goto fail;
        }

        ret = devm_request_irq(dev->dev, platform_get_irq(pdev, 0),
                               mdss_irq, 0, "mdss_isr", mdp5_mdss);
        if (ret) {
                dev_err(dev->dev, "failed to init irq: %d\n", ret);
                goto fail_irq;
        }

        ret = mdss_irq_domain_init(mdp5_mdss);
        if (ret) {
                dev_err(dev->dev, "failed to init sub-block irqs: %d\n", ret);
                goto fail_irq;
        }

        mdp5_mdss->base.funcs = &mdss_funcs;
        priv->mdss = &mdp5_mdss->base;

        pm_runtime_enable(dev->dev);

        return 0;
fail_irq:
        regulator_disable(mdp5_mdss->vdd);
fail:
        return ret;
}