// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2018 BayLibre, SAS
 * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
 * Copyright (C) 2014 Endless Mobile
 */

#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/soc/amlogic/meson-canvas.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/io.h>

#define NUM_CANVAS 256

/* DMC Registers */
#define DMC_CAV_LUT_DATAL       0x00
        #define CANVAS_WIDTH_LBIT       29
        #define CANVAS_WIDTH_LWID       3
#define DMC_CAV_LUT_DATAH       0x04
        #define CANVAS_WIDTH_HBIT       0
        #define CANVAS_HEIGHT_BIT       9
        #define CANVAS_WRAP_BIT         22
        #define CANVAS_BLKMODE_BIT      24
        #define CANVAS_ENDIAN_BIT       26
#define DMC_CAV_LUT_ADDR        0x08
        #define CANVAS_LUT_WR_EN        BIT(9)
        #define CANVAS_LUT_RD_EN        BIT(8)

struct meson_canvas {
        struct device *dev;
        void __iomem *reg_base;
        spinlock_t lock; /* canvas device lock */
        u8 used[NUM_CANVAS];
        bool supports_endianness;
};

static void canvas_write(struct meson_canvas *canvas, u32 reg, u32 val)
{
        writel_relaxed(val, canvas->reg_base + reg);
}

static u32 canvas_read(struct meson_canvas *canvas, u32 reg)
{
        return readl_relaxed(canvas->reg_base + reg);
}

struct meson_canvas *meson_canvas_get(struct device *dev)
{
        struct device_node *canvas_node;
        struct platform_device *canvas_pdev;
        struct meson_canvas *canvas;

        canvas_node = of_parse_phandle(dev->of_node, "amlogic,canvas", 0);
        if (!canvas_node)
                return ERR_PTR(-ENODEV);

        canvas_pdev = of_find_device_by_node(canvas_node);
        of_node_put(canvas_node);
        if (!canvas_pdev)
                return ERR_PTR(-EPROBE_DEFER);

        /*
         * If priv is NULL, it's probably because the canvas hasn't
         * properly initialized. Bail out with -EINVAL because, in the
         * current state, this driver probe cannot return -EPROBE_DEFER
         */
        canvas = dev_get_drvdata(&canvas_pdev->dev);
        put_device(&canvas_pdev->dev);
        if (!canvas)
                return ERR_PTR(-EINVAL);

        return canvas;
}
EXPORT_SYMBOL_GPL(meson_canvas_get);

int meson_canvas_config(struct meson_canvas *canvas, u8 canvas_index,
                        u32 addr, u32 stride, u32 height,
                        unsigned int wrap,
                        unsigned int blkmode,
                        unsigned int endian)
{
        unsigned long flags;

        if (endian && !canvas->supports_endianness) {
                dev_err(canvas->dev,
                        "Endianness is not supported on this SoC\n");
                return -EINVAL;
        }

        spin_lock_irqsave(&canvas->lock, flags);
        if (!canvas->used[canvas_index]) {
                dev_err(canvas->dev,
                        "Trying to setup non allocated canvas %u\n",
                        canvas_index);
                spin_unlock_irqrestore(&canvas->lock, flags);
                return -EINVAL;
        }

        canvas_write(canvas, DMC_CAV_LUT_DATAL,
                     ((addr + 7) >> 3) |
                     (((stride + 7) >> 3) << CANVAS_WIDTH_LBIT));

        canvas_write(canvas, DMC_CAV_LUT_DATAH,
                     ((((stride + 7) >> 3) >> CANVAS_WIDTH_LWID) <<
                                                CANVAS_WIDTH_HBIT) |
                     (height << CANVAS_HEIGHT_BIT) |
                     (wrap << CANVAS_WRAP_BIT) |
                     (blkmode << CANVAS_BLKMODE_BIT) |
                     (endian << CANVAS_ENDIAN_BIT));

        canvas_write(canvas, DMC_CAV_LUT_ADDR,
                     CANVAS_LUT_WR_EN | canvas_index);

        /* Force a read-back to make sure everything is flushed. */
        canvas_read(canvas, DMC_CAV_LUT_DATAH);
        spin_unlock_irqrestore(&canvas->lock, flags);

        return 0;
}
EXPORT_SYMBOL_GPL(meson_canvas_config);

int meson_canvas_alloc(struct meson_canvas *canvas, u8 *canvas_index)
{
        int i;
        unsigned long flags;

        spin_lock_irqsave(&canvas->lock, flags);
        for (i = 0; i < NUM_CANVAS; ++i) {
                if (!canvas->used[i]) {
                        canvas->used[i] = 1;
                        spin_unlock_irqrestore(&canvas->lock, flags);
                        *canvas_index = i;
                        return 0;
                }
        }
        spin_unlock_irqrestore(&canvas->lock, flags);

        dev_err(canvas->dev, "No more canvas available\n");
        return -ENODEV;
}
EXPORT_SYMBOL_GPL(meson_canvas_alloc);

int meson_canvas_free(struct meson_canvas *canvas, u8 canvas_index)
{
        unsigned long flags;

        spin_lock_irqsave(&canvas->lock, flags);
        if (!canvas->used[canvas_index]) {
                dev_err(canvas->dev,
                        "Trying to free unused canvas %u\n", canvas_index);
                spin_unlock_irqrestore(&canvas->lock, flags);
                return -EINVAL;
        }
        canvas->used[canvas_index] = 0;
        spin_unlock_irqrestore(&canvas->lock, flags);

        return 0;
}
EXPORT_SYMBOL_GPL(meson_canvas_free);

static int meson_canvas_probe(struct platform_device *pdev)
{
        struct meson_canvas *canvas;
        struct device *dev = &pdev->dev;

        canvas = devm_kzalloc(dev, sizeof(*canvas), GFP_KERNEL);
        if (!canvas)
                return -ENOMEM;

        canvas->reg_base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(canvas->reg_base))
                return PTR_ERR(canvas->reg_base);

        canvas->supports_endianness = of_device_get_match_data(dev);

        canvas->dev = dev;
        spin_lock_init(&canvas->lock);
        dev_set_drvdata(dev, canvas);

        return 0;
}

static const struct of_device_id canvas_dt_match[] = {
        { .compatible = "amlogic,meson8-canvas", .data = (void *)false, },
        { .compatible = "amlogic,meson8b-canvas", .data = (void *)false, },
        { .compatible = "amlogic,meson8m2-canvas", .data = (void *)false, },
        { .compatible = "amlogic,canvas", .data = (void *)true, },
        {}
};
MODULE_DEVICE_TABLE(of, canvas_dt_match);

static struct platform_driver meson_canvas_driver = {
        .probe = meson_canvas_probe,
        .driver = {
                .name = "amlogic-canvas",
                .of_match_table = canvas_dt_match,
        },
};
module_platform_driver(meson_canvas_driver);

MODULE_DESCRIPTION("Amlogic Canvas driver");
MODULE_AUTHOR("Maxime Jourdan <mjourdan@baylibre.com>");
MODULE_LICENSE("GPL");