// SPDX-License-Identifier: GPL-2.0
/*
 *    Filename: cfag12864bfb.c
 *     Version: 0.1.0
 * Description: cfag12864b LCD framebuffer driver
 *     Depends: cfag12864b
 *
 *      Author: Copyright (C) Miguel Ojeda <ojeda@kernel.org>
 *        Date: 2006-10-31
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fb.h>
#include <linux/mm.h>
#include <linux/platform_device.h>
#include <linux/cfag12864b.h>

#define CFAG12864BFB_NAME "cfag12864bfb"

static const struct fb_fix_screeninfo cfag12864bfb_fix = {
        .id = "cfag12864b",
        .type = FB_TYPE_PACKED_PIXELS,
        .visual = FB_VISUAL_MONO10,
        .xpanstep = 0,
        .ypanstep = 0,
        .ywrapstep = 0,
        .line_length = CFAG12864B_WIDTH / 8,
        .accel = FB_ACCEL_NONE,
};

static const struct fb_var_screeninfo cfag12864bfb_var = {
        .xres = CFAG12864B_WIDTH,
        .yres = CFAG12864B_HEIGHT,
        .xres_virtual = CFAG12864B_WIDTH,
        .yres_virtual = CFAG12864B_HEIGHT,
        .bits_per_pixel = 1,
        .red = { 0, 1, 0 },
        .green = { 0, 1, 0 },
        .blue = { 0, 1, 0 },
        .left_margin = 0,
        .right_margin = 0,
        .upper_margin = 0,
        .lower_margin = 0,
        .vmode = FB_VMODE_NONINTERLACED,
};

static int cfag12864bfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
        struct page *pages = virt_to_page(cfag12864b_buffer);

        vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);

        return vm_map_pages_zero(vma, &pages, 1);
}

static const struct fb_ops cfag12864bfb_ops = {
        .owner = THIS_MODULE,
        __FB_DEFAULT_SYSMEM_OPS_RDWR,
        __FB_DEFAULT_SYSMEM_OPS_DRAW,
        .fb_mmap = cfag12864bfb_mmap,
};

static int cfag12864bfb_probe(struct platform_device *device)
{
        int ret = -EINVAL;
        struct fb_info *info = framebuffer_alloc(0, &device->dev);

        if (!info)
                goto none;

        info->flags = FBINFO_VIRTFB;
        info->screen_buffer = cfag12864b_buffer;
        info->screen_size = CFAG12864B_SIZE;
        info->fbops = &cfag12864bfb_ops;
        info->fix = cfag12864bfb_fix;
        info->var = cfag12864bfb_var;
        info->pseudo_palette = NULL;
        info->par = NULL;

        if (register_framebuffer(info) < 0)
                goto fballoced;

        platform_set_drvdata(device, info);

        fb_info(info, "%s frame buffer device\n", info->fix.id);

        return 0;

fballoced:
        framebuffer_release(info);

none:
        return ret;
}

static void cfag12864bfb_remove(struct platform_device *device)
{
        struct fb_info *info = platform_get_drvdata(device);

        if (info) {
                unregister_framebuffer(info);
                framebuffer_release(info);
        }
}

static struct platform_driver cfag12864bfb_driver = {
        .probe  = cfag12864bfb_probe,
        .remove = cfag12864bfb_remove,
        .driver = {
                .name   = CFAG12864BFB_NAME,
        },
};

static struct platform_device *cfag12864bfb_device;

static int __init cfag12864bfb_init(void)
{
        int ret = -EINVAL;

        /* cfag12864b_init() must be called first */
        if (!cfag12864b_isinited()) {
                printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
                        "cfag12864b is not initialized\n");
                goto none;
        }

        if (cfag12864b_enable()) {
                printk(KERN_ERR CFAG12864BFB_NAME ": ERROR: "
                        "can't enable cfag12864b refreshing (being used)\n");
                return -ENODEV;
        }

        ret = platform_driver_register(&cfag12864bfb_driver);

        if (!ret) {
                cfag12864bfb_device =
                        platform_device_alloc(CFAG12864BFB_NAME, 0);

                if (cfag12864bfb_device)
                        ret = platform_device_add(cfag12864bfb_device);
                else
                        ret = -ENOMEM;

                if (ret) {
                        platform_device_put(cfag12864bfb_device);
                        platform_driver_unregister(&cfag12864bfb_driver);
                }
        }

none:
        return ret;
}

static void __exit cfag12864bfb_exit(void)
{
        platform_device_unregister(cfag12864bfb_device);
        platform_driver_unregister(&cfag12864bfb_driver);
        cfag12864b_disable();
}

module_init(cfag12864bfb_init);
module_exit(cfag12864bfb_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Miguel Ojeda <ojeda@kernel.org>");
MODULE_DESCRIPTION("cfag12864b LCD framebuffer driver");