linux/drivers/auxdisplay/cfag12864bfb.c

// 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");