From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001
From: Eduard Zingerman <eddyz87@gmail.com>
Date: Fri, 4 Sep 2026 17:05:56 -0700
Subject: bpf: mark a NULL kfunc argument precise

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 drivers/video/fbdev/clps711x-fb.c | 374 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 374 insertions(+)
 create mode 100644 drivers/video/fbdev/clps711x-fb.c

(limited to 'drivers/video/fbdev/clps711x-fb.c')

diff --git a/drivers/video/fbdev/clps711x-fb.c b/drivers/video/fbdev/clps711x-fb.c
new file mode 100644
index 000000000..7a7db7100
--- /dev/null
+++ b/drivers/video/fbdev/clps711x-fb.c
@@ -0,0 +1,374 @@
+// 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);
+
+	cfb->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(cfb->base)) {
+		ret = PTR_ERR(cfb->base);
+		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");
-- 
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