V4L/DVB (8914): cx18: Throttle mmio to/from the CX23418 so boards work in older systems

cx18: Throttle mmio to/from the CX23418 so boards work in older systems.  The
CX23418 couldn't reliably handle mmio at the rate at which the cx18 driver was
attempting to access the chip.  The PCI bridge arrangements and settings on
modern motherboards still allowed the CX23418 to work OK, but it didn't work
well on many older motherboards: mysterious I2C errors, firmware loading errors,
etc.  This patch adds a throttle to *all* mmio access to the CX23418.  It
defaults to a delay of 31 ns, but is adjustable by the mmio_ndelay module parm.
My HVR-1600 and Raptor PAL/SECAM card now function for analog capture on a
motherboard with an Intel 82810E Northbridge and 82801AA Southbridge.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 54 insertions, 61 deletions

diff --git a/drivers/media/video/cx18/cx18-io.c b/drivers/media/video/cx18/cx18-io.c
index c53d9b6e5e46..d92f627d35e4 100644
--- a/drivers/media/video/cx18/cx18-io.c
+++ b/drivers/media/video/cx18/cx18-io.c
@@ -21,76 +21,69 @@
  */
 
 #include "cx18-driver.h"
+#include "cx18-io.h"
 #include "cx18-irq.h"
 
-void cx18_raw_writel(struct cx18 *cx, u32 val, void __iomem *addr)
-{
-	__raw_writel(val, addr);
-}
-
-u32 cx18_raw_readl(struct cx18 *cx, const void __iomem *addr)
-{
-	return __raw_readl(addr);
-}
-
-u32 cx18_write_sync(struct cx18 *cx, u32 val, void __iomem *addr)
-{
-	writel(val, addr);
-	return readl(addr);
-}
-
-void cx18_writel(struct cx18 *cx, u32 val, void __iomem *addr)
-{
-	writel(val, addr);
-}
-
-u32 cx18_readl(struct cx18 *cx, const void __iomem *addr)
-{
-	return readl(addr);
-}
-
-
-/* Access "register" region of CX23418 memory mapped I/O */
-u32 cx18_read_reg(struct cx18 *cx, u32 reg)
-{
-	return readl(cx->reg_mem + reg);
-}
-
-void cx18_write_reg(struct cx18 *cx, u32 val, u32 reg)
-{
-	writel(val, cx->reg_mem + reg);
-}
-
-u32 cx18_write_reg_sync(struct cx18 *cx, u32 val, u32 reg)
-{
-	return cx18_write_sync(cx, val, cx->reg_mem + reg);
-}
-
-/* Access "encoder memory" region of CX23418 memory mapped I/O */
-u32 cx18_read_enc(struct cx18 *cx, u32 addr)
-{
-	return readl(cx->enc_mem + addr);
-}
-
-void cx18_write_enc(struct cx18 *cx, u32 val, u32 addr)
-{
-	writel(val, cx->enc_mem + addr);
-}
-
-u32 cx18_write_enc_sync(struct cx18 *cx, u32 val, u32 addr)
-{
-	return cx18_write_sync(cx, val, cx->enc_mem + addr);
-}
-
 void cx18_memcpy_fromio(struct cx18 *cx, void *to,
 			const void __iomem *from, unsigned int len)
 {
-	memcpy_fromio(to, from, len);
+	/* Align reads on the CX23418's addresses */
+	if ((len > 0) && ((unsigned)from & 1)) {
+		*((u8 *)to) = cx18_readb(cx, from);
+		len--;
+		to++;
+		from++;
+	}
+	if ((len > 1) && ((unsigned)from & 2)) {
+		*((u16 *)to) = cx18_raw_readw(cx, from);
+		len -= 2;
+		to += 2;
+		from += 2;
+	}
+	while (len > 3) {
+		*((u32 *)to) = cx18_raw_readl(cx, from);
+		len -= 4;
+		to += 4;
+		from += 4;
+	}
+	if (len > 1) {
+		*((u16 *)to) = cx18_raw_readw(cx, from);
+		len -= 2;
+		to += 2;
+		from += 2;
+	}
+	if (len > 0)
+		*((u8 *)to) = cx18_readb(cx, from);
 }
 
 void cx18_memset_io(struct cx18 *cx, void __iomem *addr, int val, size_t count)
 {
-	memset_io(addr, val, count);
+	u16 val2 = val | (val << 8);
+	u32 val4 = val2 | (val2 << 16);
+
+	/* Align writes on the CX23418's addresses */
+	if ((count > 0) && ((unsigned)addr & 1)) {
+		cx18_writeb(cx, (u8) val, addr);
+		count--;
+		addr++;
+	}
+	if ((count > 1) && ((unsigned)addr & 2)) {
+		cx18_writew(cx, val2, addr);
+		count -= 2;
+		addr += 2;
+	}
+	while (count > 3) {
+		cx18_writel(cx, val4, addr);
+		count -= 4;
+		addr += 4;
+	}
+	if (count > 1) {
+		cx18_writew(cx, val2, addr);
+		count -= 2;
+		addr += 2;
+	}
+	if (count > 0)
+		cx18_writeb(cx, (u8) val, addr);
 }
 
 void cx18_sw1_irq_enable(struct cx18 *cx, u32 val)