Re: [PATCH v7 1/7] fbdev/hitfb: Cast I/O offset to address

Helge Deller <deller@xxxxxx> · Tue, 16 May 2023 19:44:09 +0200

On 5/12/23 12:24, Thomas Zimmermann wrote:
Cast I/O offsets to pointers to use them with I/O functions. The I/O
functions expect pointers of type 'volatile void __iomem *', but the
offsets are plain integers. Build warnings are

   ../drivers/video/fbdev/hitfb.c: In function 'hitfb_accel_wait':
   ../arch/x86/include/asm/hd64461.h:18:33: warning: passing argument 1 of 'fb_readw' makes pointer from integer without a cast [-Wint-conversion]
    18 | #define HD64461_IO_OFFSET(x)    (HD64461_IOBASE + (x))
       |                                 ^~~~~~~~~~~~~~~~~~~~~~
       |                                 |
       |                                 unsigned int
   ../arch/x86/include/asm/hd64461.h:93:33: note: in expansion of macro 'HD64461_IO_OFFSET'
    93 | #define HD64461_GRCFGR          HD64461_IO_OFFSET(0x1044)       /* Accelerator Configuration Register */
       |                                 ^~~~~~~~~~~~~~~~~
   ../drivers/video/fbdev/hitfb.c:47:25: note: in expansion of macro 'HD64461_GRCFGR'
    47 |         while (fb_readw(HD64461_GRCFGR) & HD64461_GRCFGR_ACCSTATUS) ;
       |                         ^~~~~~~~~~~~~~
   In file included from ../arch/x86/include/asm/fb.h:15,
   from ../include/linux/fb.h:19,
   from ../drivers/video/fbdev/hitfb.c:22:
   ../include/asm-generic/fb.h:52:57: note: expected 'const volatile void *' but argument is of type 'unsigned int'
    52 | static inline u16 fb_readw(const volatile void __iomem *addr)
       |                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~

This patch only fixes the build warnings. It's not clear if the I/O
offsets can legally be passed to the I/O helpers. It was apparently
broken in 2007 when custom inw()/outw() helpers got removed by
commit 34a780a0afeb ("sh: hp6xx pata_platform support."). Fixing the
driver would require setting the I/O base address.

I think your patch is the best you can do for now... So...

Acked-by: Helge Deller <deller@xxxxxx>

Thanks!
Helge


Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202305102136.eMjTSPwH-lkp@xxxxxxxxx/
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: Artur Rojek <contact@xxxxxxxxxxxxxx>
---
  drivers/video/fbdev/hitfb.c | 122 ++++++++++++++++++++----------------
  1 file changed, 69 insertions(+), 53 deletions(-)

diff --git a/drivers/video/fbdev/hitfb.c b/drivers/video/fbdev/hitfb.c
index 3033f5056976..7737923b7a0a 100644
--- a/drivers/video/fbdev/hitfb.c
+++ b/drivers/video/fbdev/hitfb.c
@@ -42,17 +42,33 @@ static struct fb_fix_screeninfo hitfb_fix = {
  	.accel		= FB_ACCEL_NONE,
  };

+static volatile void __iomem *hitfb_offset_to_addr(unsigned int offset)
+{
+	return (__force volatile void __iomem *)(uintptr_t)offset;
+}
+
+static u16 hitfb_readw(unsigned int offset)
+{
+	return fb_readw(hitfb_offset_to_addr(offset));
+}
+
+static void hitfb_writew(u16 value, unsigned int offset)
+{
+	fb_writew(value, hitfb_offset_to_addr(offset));
+}
+
  static inline void hitfb_accel_wait(void)
  {
-	while (fb_readw(HD64461_GRCFGR) & HD64461_GRCFGR_ACCSTATUS) ;
+	while (hitfb_readw(HD64461_GRCFGR) & HD64461_GRCFGR_ACCSTATUS)
+		;
  }

  static inline void hitfb_accel_start(int truecolor)
  {
  	if (truecolor) {
-		fb_writew(6, HD64461_GRCFGR);
+		hitfb_writew(6, HD64461_GRCFGR);
  	} else {
-		fb_writew(7, HD64461_GRCFGR);
+		hitfb_writew(7, HD64461_GRCFGR);
  	}
  }

@@ -63,11 +79,11 @@ static inline void hitfb_accel_set_dest(int truecolor, u16 dx, u16 dy,
  	if (truecolor)
  		saddr <<= 1;

-	fb_writew(width-1, HD64461_BBTDWR);
-	fb_writew(height-1, HD64461_BBTDHR);
+	hitfb_writew(width-1, HD64461_BBTDWR);
+	hitfb_writew(height-1, HD64461_BBTDHR);

-	fb_writew(saddr & 0xffff, HD64461_BBTDSARL);
-	fb_writew(saddr >> 16, HD64461_BBTDSARH);
+	hitfb_writew(saddr & 0xffff, HD64461_BBTDSARL);
+	hitfb_writew(saddr >> 16, HD64461_BBTDSARH);

  }

@@ -80,7 +96,7 @@ static inline void hitfb_accel_bitblt(int truecolor, u16 sx, u16 sy, u16 dx,

  	height--;
  	width--;
-	fb_writew(rop, HD64461_BBTROPR);
+	hitfb_writew(rop, HD64461_BBTROPR);
  	if ((sy < dy) || ((sy == dy) && (sx <= dx))) {
  		saddr = WIDTH * (sy + height) + sx + width;
  		daddr = WIDTH * (dy + height) + dx + width;
@@ -91,32 +107,32 @@ static inline void hitfb_accel_bitblt(int truecolor, u16 sx, u16 sy, u16 dx,
  				maddr =
  				    (((width >> 4) + 1) * (height + 1) - 1) * 2;

-			fb_writew((1 << 5) | 1, HD64461_BBTMDR);
+			hitfb_writew((1 << 5) | 1, HD64461_BBTMDR);
  		} else
-			fb_writew(1, HD64461_BBTMDR);
+			hitfb_writew(1, HD64461_BBTMDR);
  	} else {
  		saddr = WIDTH * sy + sx;
  		daddr = WIDTH * dy + dx;
  		if (mask_addr) {
-			fb_writew((1 << 5), HD64461_BBTMDR);
+			hitfb_writew((1 << 5), HD64461_BBTMDR);
  		} else {
-			fb_writew(0, HD64461_BBTMDR);
+			hitfb_writew(0, HD64461_BBTMDR);
  		}
  	}
  	if (truecolor) {
  		saddr <<= 1;
  		daddr <<= 1;
  	}
-	fb_writew(width, HD64461_BBTDWR);
-	fb_writew(height, HD64461_BBTDHR);
-	fb_writew(saddr & 0xffff, HD64461_BBTSSARL);
-	fb_writew(saddr >> 16, HD64461_BBTSSARH);
-	fb_writew(daddr & 0xffff, HD64461_BBTDSARL);
-	fb_writew(daddr >> 16, HD64461_BBTDSARH);
+	hitfb_writew(width, HD64461_BBTDWR);
+	hitfb_writew(height, HD64461_BBTDHR);
+	hitfb_writew(saddr & 0xffff, HD64461_BBTSSARL);
+	hitfb_writew(saddr >> 16, HD64461_BBTSSARH);
+	hitfb_writew(daddr & 0xffff, HD64461_BBTDSARL);
+	hitfb_writew(daddr >> 16, HD64461_BBTDSARH);
  	if (mask_addr) {
  		maddr += mask_addr;
-		fb_writew(maddr & 0xffff, HD64461_BBTMARL);
-		fb_writew(maddr >> 16, HD64461_BBTMARH);
+		hitfb_writew(maddr & 0xffff, HD64461_BBTMARL);
+		hitfb_writew(maddr >> 16, HD64461_BBTMARH);
  	}
  	hitfb_accel_start(truecolor);
  }
@@ -127,17 +143,17 @@ static void hitfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
  		cfb_fillrect(p, rect);
  	else {
  		hitfb_accel_wait();
-		fb_writew(0x00f0, HD64461_BBTROPR);
-		fb_writew(16, HD64461_BBTMDR);
+		hitfb_writew(0x00f0, HD64461_BBTROPR);
+		hitfb_writew(16, HD64461_BBTMDR);

  		if (p->var.bits_per_pixel == 16) {
-			fb_writew(((u32 *) (p->pseudo_palette))[rect->color],
+			hitfb_writew(((u32 *) (p->pseudo_palette))[rect->color],
  				  HD64461_GRSCR);
  			hitfb_accel_set_dest(1, rect->dx, rect->dy, rect->width,
  					     rect->height);
  			hitfb_accel_start(1);
  		} else {
-			fb_writew(rect->color, HD64461_GRSCR);
+			hitfb_writew(rect->color, HD64461_GRSCR);
  			hitfb_accel_set_dest(0, rect->dx, rect->dy, rect->width,
  					     rect->height);
  			hitfb_accel_start(0);
@@ -162,7 +178,7 @@ static int hitfb_pan_display(struct fb_var_screeninfo *var,
  	if (xoffset != 0)
  		return -EINVAL;

-	fb_writew((yoffset*info->fix.line_length)>>10, HD64461_LCDCBAR);
+	hitfb_writew((yoffset*info->fix.line_length)>>10, HD64461_LCDCBAR);

  	return 0;
  }
@@ -172,33 +188,33 @@ int hitfb_blank(int blank_mode, struct fb_info *info)
  	unsigned short v;

  	if (blank_mode) {
-		v = fb_readw(HD64461_LDR1);
+		v = hitfb_readw(HD64461_LDR1);
  		v &= ~HD64461_LDR1_DON;
-		fb_writew(v, HD64461_LDR1);
+		hitfb_writew(v, HD64461_LDR1);

-		v = fb_readw(HD64461_LCDCCR);
+		v = hitfb_readw(HD64461_LCDCCR);
  		v |= HD64461_LCDCCR_MOFF;
-		fb_writew(v, HD64461_LCDCCR);
+		hitfb_writew(v, HD64461_LCDCCR);

-		v = fb_readw(HD64461_STBCR);
+		v = hitfb_readw(HD64461_STBCR);
  		v |= HD64461_STBCR_SLCDST;
-		fb_writew(v, HD64461_STBCR);
+		hitfb_writew(v, HD64461_STBCR);
  	} else {
-		v = fb_readw(HD64461_STBCR);
+		v = hitfb_readw(HD64461_STBCR);
  		v &= ~HD64461_STBCR_SLCDST;
-		fb_writew(v, HD64461_STBCR);
+		hitfb_writew(v, HD64461_STBCR);

-		v = fb_readw(HD64461_LCDCCR);
+		v = hitfb_readw(HD64461_LCDCCR);
  		v &= ~(HD64461_LCDCCR_MOFF | HD64461_LCDCCR_STREQ);
-		fb_writew(v, HD64461_LCDCCR);
+		hitfb_writew(v, HD64461_LCDCCR);

  		do {
-		    v = fb_readw(HD64461_LCDCCR);
+		    v = hitfb_readw(HD64461_LCDCCR);
  		} while(v&HD64461_LCDCCR_STBACK);

-		v = fb_readw(HD64461_LDR1);
+		v = hitfb_readw(HD64461_LDR1);
  		v |= HD64461_LDR1_DON;
-		fb_writew(v, HD64461_LDR1);
+		hitfb_writew(v, HD64461_LDR1);
  	}
  	return 0;
  }
@@ -211,10 +227,10 @@ static int hitfb_setcolreg(unsigned regno, unsigned red, unsigned green,

  	switch (info->var.bits_per_pixel) {
  	case 8:
-		fb_writew(regno << 8, HD64461_CPTWAR);
-		fb_writew(red >> 10, HD64461_CPTWDR);
-		fb_writew(green >> 10, HD64461_CPTWDR);
-		fb_writew(blue >> 10, HD64461_CPTWDR);
+		hitfb_writew(regno << 8, HD64461_CPTWAR);
+		hitfb_writew(red >> 10, HD64461_CPTWDR);
+		hitfb_writew(green >> 10, HD64461_CPTWDR);
+		hitfb_writew(blue >> 10, HD64461_CPTWDR);
  		break;
  	case 16:
  		if (regno >= 16)
@@ -302,11 +318,11 @@ static int hitfb_set_par(struct fb_info *info)
  		break;
  	}

-	fb_writew(info->fix.line_length, HD64461_LCDCLOR);
-	ldr3 = fb_readw(HD64461_LDR3);
+	hitfb_writew(info->fix.line_length, HD64461_LCDCLOR);
+	ldr3 = hitfb_readw(HD64461_LDR3);
  	ldr3 &= ~15;
  	ldr3 |= (info->var.bits_per_pixel == 8) ? 4 : 8;
-	fb_writew(ldr3, HD64461_LDR3);
+	hitfb_writew(ldr3, HD64461_LDR3);
  	return 0;
  }

@@ -337,9 +353,9 @@ static int hitfb_probe(struct platform_device *dev)
  	hitfb_fix.smem_start = HD64461_IO_OFFSET(0x02000000);
  	hitfb_fix.smem_len = 512 * 1024;

-	lcdclor = fb_readw(HD64461_LCDCLOR);
-	ldvndr = fb_readw(HD64461_LDVNDR);
-	ldr3 = fb_readw(HD64461_LDR3);
+	lcdclor = hitfb_readw(HD64461_LCDCLOR);
+	ldvndr = hitfb_readw(HD64461_LDVNDR);
+	ldr3 = hitfb_readw(HD64461_LDR3);

  	switch (ldr3 & 15) {
  	default:
@@ -429,9 +445,9 @@ static int hitfb_suspend(struct device *dev)
  	u16 v;

  	hitfb_blank(1,0);
-	v = fb_readw(HD64461_STBCR);
+	v = hitfb_readw(HD64461_STBCR);
  	v |= HD64461_STBCR_SLCKE_IST;
-	fb_writew(v, HD64461_STBCR);
+	hitfb_writew(v, HD64461_STBCR);

  	return 0;
  }
@@ -440,12 +456,12 @@ static int hitfb_resume(struct device *dev)
  {
  	u16 v;

-	v = fb_readw(HD64461_STBCR);
+	v = hitfb_readw(HD64461_STBCR);
  	v &= ~HD64461_STBCR_SLCKE_OST;
  	msleep(100);
-	v = fb_readw(HD64461_STBCR);
+	v = hitfb_readw(HD64461_STBCR);
  	v &= ~HD64461_STBCR_SLCKE_IST;
-	fb_writew(v, HD64461_STBCR);
+	hitfb_writew(v, HD64461_STBCR);
  	hitfb_blank(0,0);

  	return 0;








