// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Cirrus Logic CLPS711X FB driver
 *
 * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
 * Based on driver by Russell King <rmk@arm.linux.org.uk>
 */

#include <linux/clk.h>
#include <linux/fb.h>
#include <linux/io.h>
#include <linux/lcd.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/clps711x.h>
#include <linux/regulator/consumer.h>
#include <video/of_display_timing.h>

#define CLPS711X_FB_NAME        "clps711x-fb"
#define CLPS711X_FB_BPP_MAX     (4)

/* Registers relative to LCDCON */
#define CLPS711X_LCDCON         (0x0000)
# define LCDCON_GSEN            BIT(30)
# define LCDCON_GSMD            BIT(31)
#define CLPS711X_PALLSW         (0x0280)
#define CLPS711X_PALMSW         (0x02c0)
#define CLPS711X_FBADDR         (0x0d40)

struct clps711x_fb_info {
        struct clk              *clk;
        void __iomem            *base;
        struct regmap           *syscon;
        resource_size_t         buffsize;
        struct fb_videomode     mode;
        struct regulator        *lcd_pwr;
        u32                     ac_prescale;
        bool                    cmap_invert;
};

static int clps711x_fb_setcolreg(u_int regno, u_int red, u_int green,
                                 u_int blue, u_int transp, struct fb_info *info)
{
        struct clps711x_fb_info *cfb = info->par;
        u32 level, mask, shift;

        if (regno >= BIT(info->var.bits_per_pixel))
                return -EINVAL;

        shift = 4 * (regno & 7);
        mask  = 0xf << shift;
        /* gray = 0.30*R + 0.58*G + 0.11*B */
        level = (((red * 77 + green * 151 + blue * 28) >> 20) << shift) & mask;
        if (cfb->cmap_invert)
                level = 0xf - level;

        regno = (regno < 8) ? CLPS711X_PALLSW : CLPS711X_PALMSW;

        writel((readl(cfb->base + regno) & ~mask) | level, cfb->base + regno);

        return 0;
}

static int clps711x_fb_check_var(struct fb_var_screeninfo *var,
                                 struct fb_info *info)
{
        u32 val;

        if (var->bits_per_pixel < 1 ||
            var->bits_per_pixel > CLPS711X_FB_BPP_MAX)
                return -EINVAL;

        if (!var->pixclock)
                return -EINVAL;

        val = DIV_ROUND_UP(var->xres, 16) - 1;
        if (val < 0x01 || val > 0x3f)
                return -EINVAL;

        val = DIV_ROUND_UP(var->yres * var->xres * var->bits_per_pixel, 128);
        val--;
        if (val < 0x001 || val > 0x1fff)
                return -EINVAL;

        var->transp.msb_right   = 0;
        var->transp.offset      = 0;
        var->transp.length      = 0;
        var->red.msb_right      = 0;
        var->red.offset         = 0;
        var->red.length         = var->bits_per_pixel;
        var->green              = var->red;
        var->blue               = var->red;
        var->grayscale          = var->bits_per_pixel > 1;

        return 0;
}

static int clps711x_fb_set_par(struct fb_info *info)
{
        struct clps711x_fb_info *cfb = info->par;
        resource_size_t size;
        u32 lcdcon, pps;

        size = (info->var.xres * info->var.yres * info->var.bits_per_pixel) / 8;
        if (size > cfb->buffsize)
                return -EINVAL;

        switch (info->var.bits_per_pixel) {
        case 1:
                info->fix.visual = FB_VISUAL_MONO01;
                break;
        case 2:
        case 4:
                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
                break;
        default:
                return -EINVAL;
        }

        info->fix.line_length = info->var.xres * info->var.bits_per_pixel / 8;
        info->fix.smem_len = size;

        lcdcon = (info->var.xres * info->var.yres *
                  info->var.bits_per_pixel) / 128 - 1;
        lcdcon |= ((info->var.xres / 16) - 1) << 13;
        lcdcon |= (cfb->ac_prescale & 0x1f) << 25;

        pps = clk_get_rate(cfb->clk) / (PICOS2KHZ(info->var.pixclock) * 1000);
        if (pps)
                pps--;
        lcdcon |= (pps & 0x3f) << 19;

        if (info->var.bits_per_pixel == 4)
                lcdcon |= LCDCON_GSMD;
        if (info->var.bits_per_pixel >= 2)
                lcdcon |= LCDCON_GSEN;

        /* LCDCON must only be changed while the LCD is disabled */
        regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
        writel(lcdcon, cfb->base + CLPS711X_LCDCON);
        regmap_update_bits(cfb->syscon, SYSCON_OFFSET,
                           SYSCON1_LCDEN, SYSCON1_LCDEN);

        return 0;
}

static int clps711x_fb_blank(int blank, struct fb_info *info)
{
        /* Return happy */
        return 0;
}

static const struct fb_ops clps711x_fb_ops = {
        .owner          = THIS_MODULE,
        FB_DEFAULT_IOMEM_OPS,
        .fb_setcolreg   = clps711x_fb_setcolreg,
        .fb_check_var   = clps711x_fb_check_var,
        .fb_set_par     = clps711x_fb_set_par,
        .fb_blank       = clps711x_fb_blank,
};

static int clps711x_lcd_get_power(struct lcd_device *lcddev)
{
        struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);

        if (!IS_ERR_OR_NULL(cfb->lcd_pwr))
                if (!regulator_is_enabled(cfb->lcd_pwr))
                        return LCD_POWER_REDUCED;

        return LCD_POWER_ON;
}

static int clps711x_lcd_set_power(struct lcd_device *lcddev, int blank)
{
        struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);

        if (!IS_ERR_OR_NULL(cfb->lcd_pwr)) {
                if (blank == LCD_POWER_ON) {
                        if (!regulator_is_enabled(cfb->lcd_pwr))
                                return regulator_enable(cfb->lcd_pwr);
                } else {
                        if (regulator_is_enabled(cfb->lcd_pwr))
                                return regulator_disable(cfb->lcd_pwr);
                }
        }

        return 0;
}

static const struct lcd_ops clps711x_lcd_ops = {
        .get_power      = clps711x_lcd_get_power,
        .set_power      = clps711x_lcd_set_power,
};

static int clps711x_fb_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *disp, *np = dev->of_node;
        struct clps711x_fb_info *cfb;
        struct lcd_device *lcd;
        struct fb_info *info;
        struct resource *res;
        int ret = -ENOENT;
        u32 val;

        if (fb_get_options(CLPS711X_FB_NAME, NULL))
                return -ENODEV;

        info = framebuffer_alloc(sizeof(*cfb), dev);
        if (!info)
                return -ENOMEM;

        cfb = info->par;
        platform_set_drvdata(pdev, info);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                goto out_fb_release;
        cfb->base = devm_ioremap(dev, res->start, resource_size(res));
        if (!cfb->base) {
                ret = -ENOMEM;
                goto out_fb_release;
        }

        info->fix.mmio_start = res->start;
        info->fix.mmio_len = resource_size(res);

        info->screen_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
        if (IS_ERR(info->screen_base)) {
                ret = PTR_ERR(info->screen_base);
                goto out_fb_release;
        }

        /* Physical address should be aligned to 256 MiB */
        if (res->start & 0x0fffffff) {
                ret = -EINVAL;
                goto out_fb_release;
        }

        cfb->buffsize = resource_size(res);
        info->fix.smem_start = res->start;

        cfb->clk = devm_clk_get(dev, NULL);
        if (IS_ERR(cfb->clk)) {
                ret = PTR_ERR(cfb->clk);
                goto out_fb_release;
        }

        cfb->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
        if (IS_ERR(cfb->syscon)) {
                ret = PTR_ERR(cfb->syscon);
                goto out_fb_release;
        }

        disp = of_parse_phandle(np, "display", 0);
        if (!disp) {
                dev_err(&pdev->dev, "No display defined\n");
                ret = -ENODATA;
                goto out_fb_release;
        }

        ret = of_get_fb_videomode(disp, &cfb->mode, OF_USE_NATIVE_MODE);
        if (ret) {
                of_node_put(disp);
                goto out_fb_release;
        }

        of_property_read_u32(disp, "ac-prescale", &cfb->ac_prescale);
        cfb->cmap_invert = of_property_read_bool(disp, "cmap-invert");

        ret = of_property_read_u32(disp, "bits-per-pixel",
                                   &info->var.bits_per_pixel);
        of_node_put(disp);
        if (ret)
                goto out_fb_release;

        /* Force disable LCD on any mismatch */
        if (info->fix.smem_start != (readb(cfb->base + CLPS711X_FBADDR) << 28))
                regmap_update_bits(cfb->syscon, SYSCON_OFFSET,
                                   SYSCON1_LCDEN, 0);

        ret = regmap_read(cfb->syscon, SYSCON_OFFSET, &val);
        if (ret)
                goto out_fb_release;

        if (!(val & SYSCON1_LCDEN)) {
                /* Setup start FB address */
                writeb(info->fix.smem_start >> 28, cfb->base + CLPS711X_FBADDR);
                /* Clean FB memory */
                memset_io(info->screen_base, 0, cfb->buffsize);
        }

        cfb->lcd_pwr = devm_regulator_get(dev, "lcd");
        if (PTR_ERR(cfb->lcd_pwr) == -EPROBE_DEFER) {
                ret = -EPROBE_DEFER;
                goto out_fb_release;
        }

        info->fbops = &clps711x_fb_ops;
        info->var.activate = FB_ACTIVATE_FORCE | FB_ACTIVATE_NOW;
        info->var.height = -1;
        info->var.width = -1;
        info->var.vmode = FB_VMODE_NONINTERLACED;
        info->fix.type = FB_TYPE_PACKED_PIXELS;
        info->fix.accel = FB_ACCEL_NONE;
        strscpy(info->fix.id, CLPS711X_FB_NAME, sizeof(info->fix.id));
        fb_videomode_to_var(&info->var, &cfb->mode);

        ret = fb_alloc_cmap(&info->cmap, BIT(CLPS711X_FB_BPP_MAX), 0);
        if (ret)
                goto out_fb_release;

        ret = fb_set_var(info, &info->var);
        if (ret)
                goto out_fb_dealloc_cmap;

        lcd = devm_lcd_device_register(dev, "clps711x-lcd", dev, cfb,
                                       &clps711x_lcd_ops);
        if (IS_ERR(lcd)) {
                ret = PTR_ERR(lcd);
                goto out_fb_dealloc_cmap;
        }

        info->lcd_dev = lcd;

        ret = register_framebuffer(info);
        if (ret)
                goto out_fb_dealloc_cmap;

        return 0;

        unregister_framebuffer(info);

out_fb_dealloc_cmap:
        regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
        fb_dealloc_cmap(&info->cmap);

out_fb_release:
        framebuffer_release(info);

        return ret;
}

static void clps711x_fb_remove(struct platform_device *pdev)
{
        struct fb_info *info = platform_get_drvdata(pdev);
        struct clps711x_fb_info *cfb = info->par;

        regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);

        unregister_framebuffer(info);
        fb_dealloc_cmap(&info->cmap);
        framebuffer_release(info);
}

static const struct of_device_id clps711x_fb_dt_ids[] = {
        { .compatible = "cirrus,ep7209-fb", },
        { }
};
MODULE_DEVICE_TABLE(of, clps711x_fb_dt_ids);

static struct platform_driver clps711x_fb_driver = {
        .driver = {
                .name           = CLPS711X_FB_NAME,
                .of_match_table = clps711x_fb_dt_ids,
        },
        .probe  = clps711x_fb_probe,
        .remove = clps711x_fb_remove,
};
module_platform_driver(clps711x_fb_driver);

MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("Cirrus Logic CLPS711X FB driver");
MODULE_LICENSE("GPL");