V4L/DVB (5502): Sn9c102: more efficient register writing code

There were many places in the driver which had long sequences of constant
register initializations.  These were done with one function call per
register.  The register address and value were immediate values in the
function calls.
This is very inefficient, as each register and value take twice the space
when they are code, as each includes a push instruction to put it on
the stack.  There there is the overhead, both size and time, for a
function call for each register.  It's also quite a few lines of C code
to do this.
The patch creates a function that writes multiple registers from a list,
and a macro that makes it easy to construct a such a list as a const
static local to send to the function.
This gets rid of quite a bit of C code, and shrinks the driver by around
8k, while at the same time being more efficient.
Acked-by: Luca Risolia <luca.risolia@studio.unibo.it>

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

13 files changed, 320 insertions, 537 deletions

diff --git a/drivers/media/video/sn9c102/sn9c102_core.c b/drivers/media/video/sn9c102/sn9c102_core.c
index f09caf2..028f173 100644
--- a/drivers/media/video/sn9c102/sn9c102_core.c
+++ b/drivers/media/video/sn9c102/sn9c102_core.c
@@ -209,27 +209,40 @@ static void sn9c102_queue_unusedframes(struct sn9c102_device* cam)
 }
 
 /*****************************************************************************/
-
-int sn9c102_write_regs(struct sn9c102_device* cam, u8* buff, u16 index)
+/*
+ * Write a sequence of count value/register pairs.  Returns -1 after the
+ * first failed write, or 0 for no errors.
+ */
+int sn9c102_write_regs(struct sn9c102_device* cam, const u8 valreg[][2],
+		       int count)
 {
 	struct usb_device* udev = cam->usbdev;
+	u8* value = cam->control_buffer;  /* Needed for DMA'able memory */
 	int i, res;
 
-	if (index + sizeof(buff) >= ARRAY_SIZE(cam->reg))
-		return -1;
+	for (i = 0; i < count; i++) {
+		u8 index = valreg[i][1];
+
+		/*
+		 * index is a u8, so it must be <256 and can't be out of range.
+		 * If we put in a check anyway, gcc annoys us with a warning
+		 * that our check is useless.  People get all uppity when they
+		 * see warnings in the kernel compile.
+		 */
+
+		*value = valreg[i][0];
+		res = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+				      0x08, 0x41, index, 0,
+				      value, 1, SN9C102_CTRL_TIMEOUT);
+		if (res < 0) {
+			DBG(3, "Failed to write a register (value 0x%02X, "
+			       "index 0x%02X, error %d)", *value, index, res);
+			return -1;
+		}
 
-	res = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0x08, 0x41,
-			      index, 0, buff, sizeof(buff),
-			      SN9C102_CTRL_TIMEOUT*sizeof(buff));
-	if (res < 0) {
-		DBG(3, "Failed to write registers (index 0x%02X, error %d)",
-		    index, res);
-		return -1;
+		cam->reg[index] = *value;
 	}
 
-	for (i = 0; i < sizeof(buff); i++)
-		cam->reg[index+i] = buff[i];
-
 	return 0;
 }
 
diff --git a/drivers/media/video/sn9c102/sn9c102_hv7131d.c b/drivers/media/video/sn9c102/sn9c102_hv7131d.c
index 9b2e2d6..28a861a 100644
--- a/drivers/media/video/sn9c102/sn9c102_hv7131d.c
+++ b/drivers/media/video/sn9c102/sn9c102_hv7131d.c
@@ -24,14 +24,11 @@
 
 static int hv7131d_init(struct sn9c102_device* cam)
 {
-	int err = 0;
+	int err;
 
-	err += sn9c102_write_reg(cam, 0x00, 0x10);
-	err += sn9c102_write_reg(cam, 0x00, 0x11);
-	err += sn9c102_write_reg(cam, 0x00, 0x14);
-	err += sn9c102_write_reg(cam, 0x60, 0x17);
-	err += sn9c102_write_reg(cam, 0x0e, 0x18);
-	err += sn9c102_write_reg(cam, 0xf2, 0x19);
+	err = sn9c102_write_const_regs(cam, {0x00, 0x10}, {0x00, 0x11},
+				       {0x00, 0x14}, {0x60, 0x17},
+				       {0x0e, 0x18}, {0xf2, 0x19});
 
 	err += sn9c102_i2c_write(cam, 0x01, 0x04);
 	err += sn9c102_i2c_write(cam, 0x02, 0x00);
@@ -247,11 +244,10 @@ static struct sn9c102_sensor hv7131d = {
 
 int sn9c102_probe_hv7131d(struct sn9c102_device* cam)
 {
-	int r0 = 0, r1 = 0, err = 0;
+	int r0 = 0, r1 = 0, err;
 
-	err += sn9c102_write_reg(cam, 0x01, 0x01);
-	err += sn9c102_write_reg(cam, 0x00, 0x01);
-	err += sn9c102_write_reg(cam, 0x28, 0x17);
+	err = sn9c102_write_const_regs(cam, {0x01, 0x01}, {0x00, 0x01},
+				       {0x28, 0x17});
 	if (err)
 		return -EIO;
 
diff --git a/drivers/media/video/sn9c102/sn9c102_hv7131r.c b/drivers/media/video/sn9c102/sn9c102_hv7131r.c
index c4a3e39..5a495ba 100644
--- a/drivers/media/video/sn9c102/sn9c102_hv7131r.c
+++ b/drivers/media/video/sn9c102/sn9c102_hv7131r.c
@@ -28,192 +28,102 @@ static int hv7131r_init(struct sn9c102_device* cam)
 
 	switch (sn9c102_get_bridge(cam)) {
 	case BRIDGE_SN9C103:
-		err += sn9c102_write_reg(cam, 0x00, 0x03);
-		err += sn9c102_write_reg(cam, 0x1a, 0x04);
-		err += sn9c102_write_reg(cam, 0x20, 0x05);
-		err += sn9c102_write_reg(cam, 0x20, 0x06);
-		err += sn9c102_write_reg(cam, 0x03, 0x10);
-		err += sn9c102_write_reg(cam, 0x00, 0x14);
-		err += sn9c102_write_reg(cam, 0x60, 0x17);
-		err += sn9c102_write_reg(cam, 0x0a, 0x18);
-		err += sn9c102_write_reg(cam, 0xf0, 0x19);
-		err += sn9c102_write_reg(cam, 0x1d, 0x1a);
-		err += sn9c102_write_reg(cam, 0x10, 0x1b);
-		err += sn9c102_write_reg(cam, 0x02, 0x1c);
-		err += sn9c102_write_reg(cam, 0x03, 0x1d);
-		err += sn9c102_write_reg(cam, 0x0f, 0x1e);
-		err += sn9c102_write_reg(cam, 0x0c, 0x1f);
-		err += sn9c102_write_reg(cam, 0x00, 0x20);
-		err += sn9c102_write_reg(cam, 0x10, 0x21);
-		err += sn9c102_write_reg(cam, 0x20, 0x22);
-		err += sn9c102_write_reg(cam, 0x30, 0x23);
-		err += sn9c102_write_reg(cam, 0x40, 0x24);
-		err += sn9c102_write_reg(cam, 0x50, 0x25);
-		err += sn9c102_write_reg(cam, 0x60, 0x26);
-		err += sn9c102_write_reg(cam, 0x70, 0x27);
-		err += sn9c102_write_reg(cam, 0x80, 0x28);
-		err += sn9c102_write_reg(cam, 0x90, 0x29);
-		err += sn9c102_write_reg(cam, 0xa0, 0x2a);
-		err += sn9c102_write_reg(cam, 0xb0, 0x2b);
-		err += sn9c102_write_reg(cam, 0xc0, 0x2c);
-		err += sn9c102_write_reg(cam, 0xd0, 0x2d);
-		err += sn9c102_write_reg(cam, 0xe0, 0x2e);
-		err += sn9c102_write_reg(cam, 0xf0, 0x2f);
-		err += sn9c102_write_reg(cam, 0xff, 0x30);
+		err = sn9c102_write_const_regs(cam, {0x00, 0x03}, {0x1a, 0x04},
+					       {0x20, 0x05}, {0x20, 0x06},
+					       {0x03, 0x10}, {0x00, 0x14},
+					       {0x60, 0x17}, {0x0a, 0x18},
+					       {0xf0, 0x19}, {0x1d, 0x1a},
+					       {0x10, 0x1b}, {0x02, 0x1c},
+					       {0x03, 0x1d}, {0x0f, 0x1e},
+					       {0x0c, 0x1f}, {0x00, 0x20},
+					       {0x10, 0x21}, {0x20, 0x22},
+					       {0x30, 0x23}, {0x40, 0x24},
+					       {0x50, 0x25}, {0x60, 0x26},
+					       {0x70, 0x27}, {0x80, 0x28},
+					       {0x90, 0x29}, {0xa0, 0x2a},
+					       {0xb0, 0x2b}, {0xc0, 0x2c},
+					       {0xd0, 0x2d}, {0xe0, 0x2e},
+					       {0xf0, 0x2f}, {0xff, 0x30});
+
 		break;
 	case BRIDGE_SN9C105:
 	case BRIDGE_SN9C120:
-		err += sn9c102_write_reg(cam, 0x44, 0x01);
-		err += sn9c102_write_reg(cam, 0x40, 0x02);
-		err += sn9c102_write_reg(cam, 0x00, 0x03);
-		err += sn9c102_write_reg(cam, 0x1a, 0x04);
-		err += sn9c102_write_reg(cam, 0x44, 0x05);
-		err += sn9c102_write_reg(cam, 0x3e, 0x06);
-		err += sn9c102_write_reg(cam, 0x1a, 0x07);
-		err += sn9c102_write_reg(cam, 0x03, 0x10);
-		err += sn9c102_write_reg(cam, 0x08, 0x14);
-		err += sn9c102_write_reg(cam, 0xa3, 0x17);
-		err += sn9c102_write_reg(cam, 0x4b, 0x18);
-		err += sn9c102_write_reg(cam, 0x00, 0x19);
-		err += sn9c102_write_reg(cam, 0x1d, 0x1a);
-		err += sn9c102_write_reg(cam, 0x10, 0x1b);
-		err += sn9c102_write_reg(cam, 0x02, 0x1c);
-		err += sn9c102_write_reg(cam, 0x03, 0x1d);
-		err += sn9c102_write_reg(cam, 0x0f, 0x1e);
-		err += sn9c102_write_reg(cam, 0x0c, 0x1f);
-		err += sn9c102_write_reg(cam, 0x00, 0x20);
-		err += sn9c102_write_reg(cam, 0x29, 0x21);
-		err += sn9c102_write_reg(cam, 0x40, 0x22);
-		err += sn9c102_write_reg(cam, 0x54, 0x23);
-		err += sn9c102_write_reg(cam, 0x66, 0x24);
-		err += sn9c102_write_reg(cam, 0x76, 0x25);
-		err += sn9c102_write_reg(cam, 0x85, 0x26);
-		err += sn9c102_write_reg(cam, 0x94, 0x27);
-		err += sn9c102_write_reg(cam, 0xa1, 0x28);
-		err += sn9c102_write_reg(cam, 0xae, 0x29);
-		err += sn9c102_write_reg(cam, 0xbb, 0x2a);
-		err += sn9c102_write_reg(cam, 0xc7, 0x2b);
-		err += sn9c102_write_reg(cam, 0xd3, 0x2c);
-		err += sn9c102_write_reg(cam, 0xde, 0x2d);
-		err += sn9c102_write_reg(cam, 0xea, 0x2e);
-		err += sn9c102_write_reg(cam, 0xf4, 0x2f);
-		err += sn9c102_write_reg(cam, 0xff, 0x30);
-		err += sn9c102_write_reg(cam, 0x00, 0x3F);
-		err += sn9c102_write_reg(cam, 0xC7, 0x40);
-		err += sn9c102_write_reg(cam, 0x01, 0x41);
-		err += sn9c102_write_reg(cam, 0x44, 0x42);
-		err += sn9c102_write_reg(cam, 0x00, 0x43);
-		err += sn9c102_write_reg(cam, 0x44, 0x44);
-		err += sn9c102_write_reg(cam, 0x00, 0x45);
-		err += sn9c102_write_reg(cam, 0x44, 0x46);
-		err += sn9c102_write_reg(cam, 0x00, 0x47);
-		err += sn9c102_write_reg(cam, 0xC7, 0x48);
-		err += sn9c102_write_reg(cam, 0x01, 0x49);
-		err += sn9c102_write_reg(cam, 0xC7, 0x4A);
-		err += sn9c102_write_reg(cam, 0x01, 0x4B);
-		err += sn9c102_write_reg(cam, 0xC7, 0x4C);
-		err += sn9c102_write_reg(cam, 0x01, 0x4D);
-		err += sn9c102_write_reg(cam, 0x44, 0x4E);
-		err += sn9c102_write_reg(cam, 0x00, 0x4F);
-		err += sn9c102_write_reg(cam, 0x44, 0x50);
-		err += sn9c102_write_reg(cam, 0x00, 0x51);
-		err += sn9c102_write_reg(cam, 0x44, 0x52);
-		err += sn9c102_write_reg(cam, 0x00, 0x53);
-		err += sn9c102_write_reg(cam, 0xC7, 0x54);
-		err += sn9c102_write_reg(cam, 0x01, 0x55);
-		err += sn9c102_write_reg(cam, 0xC7, 0x56);
-		err += sn9c102_write_reg(cam, 0x01, 0x57);
-		err += sn9c102_write_reg(cam, 0xC7, 0x58);
-		err += sn9c102_write_reg(cam, 0x01, 0x59);
-		err += sn9c102_write_reg(cam, 0x44, 0x5A);
-		err += sn9c102_write_reg(cam, 0x00, 0x5B);
-		err += sn9c102_write_reg(cam, 0x44, 0x5C);
-		err += sn9c102_write_reg(cam, 0x00, 0x5D);
-		err += sn9c102_write_reg(cam, 0x44, 0x5E);
-		err += sn9c102_write_reg(cam, 0x00, 0x5F);
-		err += sn9c102_write_reg(cam, 0xC7, 0x60);
-		err += sn9c102_write_reg(cam, 0x01, 0x61);
-		err += sn9c102_write_reg(cam, 0xC7, 0x62);
-		err += sn9c102_write_reg(cam, 0x01, 0x63);
-		err += sn9c102_write_reg(cam, 0xC7, 0x64);
-		err += sn9c102_write_reg(cam, 0x01, 0x65);
-		err += sn9c102_write_reg(cam, 0x44, 0x66);
-		err += sn9c102_write_reg(cam, 0x00, 0x67);
-		err += sn9c102_write_reg(cam, 0x44, 0x68);
-		err += sn9c102_write_reg(cam, 0x00, 0x69);
-		err += sn9c102_write_reg(cam, 0x44, 0x6A);
-		err += sn9c102_write_reg(cam, 0x00, 0x6B);
-		err += sn9c102_write_reg(cam, 0xC7, 0x6C);
-		err += sn9c102_write_reg(cam, 0x01, 0x6D);
-		err += sn9c102_write_reg(cam, 0xC7, 0x6E);
-		err += sn9c102_write_reg(cam, 0x01, 0x6F);
-		err += sn9c102_write_reg(cam, 0xC7, 0x70);
-		err += sn9c102_write_reg(cam, 0x01, 0x71);
-		err += sn9c102_write_reg(cam, 0x44, 0x72);
-		err += sn9c102_write_reg(cam, 0x00, 0x73);
-		err += sn9c102_write_reg(cam, 0x44, 0x74);
-		err += sn9c102_write_reg(cam, 0x00, 0x75);
-		err += sn9c102_write_reg(cam, 0x44, 0x76);
-		err += sn9c102_write_reg(cam, 0x00, 0x77);
-		err += sn9c102_write_reg(cam, 0xC7, 0x78);
-		err += sn9c102_write_reg(cam, 0x01, 0x79);
-		err += sn9c102_write_reg(cam, 0xC7, 0x7A);
-		err += sn9c102_write_reg(cam, 0x01, 0x7B);
-		err += sn9c102_write_reg(cam, 0xC7, 0x7C);
-		err += sn9c102_write_reg(cam, 0x01, 0x7D);
-		err += sn9c102_write_reg(cam, 0x44, 0x7E);
-		err += sn9c102_write_reg(cam, 0x00, 0x7F);
-		err += sn9c102_write_reg(cam, 0x14, 0x84);
-		err += sn9c102_write_reg(cam, 0x00, 0x85);
-		err += sn9c102_write_reg(cam, 0x27, 0x86);
-		err += sn9c102_write_reg(cam, 0x00, 0x87);
-		err += sn9c102_write_reg(cam, 0x07, 0x88);
-		err += sn9c102_write_reg(cam, 0x00, 0x89);
-		err += sn9c102_write_reg(cam, 0xEC, 0x8A);
-		err += sn9c102_write_reg(cam, 0x0f, 0x8B);
-		err += sn9c102_write_reg(cam, 0xD8, 0x8C);
-		err += sn9c102_write_reg(cam, 0x0f, 0x8D);
-		err += sn9c102_write_reg(cam, 0x3D, 0x8E);
-		err += sn9c102_write_reg(cam, 0x00, 0x8F);
-		err += sn9c102_write_reg(cam, 0x3D, 0x90);
-		err += sn9c102_write_reg(cam, 0x00, 0x91);
-		err += sn9c102_write_reg(cam, 0xCD, 0x92);
-		err += sn9c102_write_reg(cam, 0x0f, 0x93);
-		err += sn9c102_write_reg(cam, 0xf7, 0x94);
-		err += sn9c102_write_reg(cam, 0x0f, 0x95);
-		err += sn9c102_write_reg(cam, 0x0C, 0x96);
-		err += sn9c102_write_reg(cam, 0x00, 0x97);
-		err += sn9c102_write_reg(cam, 0x00, 0x98);
-		err += sn9c102_write_reg(cam, 0x66, 0x99);
-		err += sn9c102_write_reg(cam, 0x05, 0x9A);
-		err += sn9c102_write_reg(cam, 0x00, 0x9B);
-		err += sn9c102_write_reg(cam, 0x04, 0x9C);
-		err += sn9c102_write_reg(cam, 0x00, 0x9D);
-		err += sn9c102_write_reg(cam, 0x08, 0x9E);
-		err += sn9c102_write_reg(cam, 0x00, 0x9F);
-		err += sn9c102_write_reg(cam, 0x2D, 0xC0);
-		err += sn9c102_write_reg(cam, 0x2D, 0xC1);
-		err += sn9c102_write_reg(cam, 0x3A, 0xC2);
-		err += sn9c102_write_reg(cam, 0x05, 0xC3);
-		err += sn9c102_write_reg(cam, 0x04, 0xC4);
-		err += sn9c102_write_reg(cam, 0x3F, 0xC5);
-		err += sn9c102_write_reg(cam, 0x00, 0xC6);
-		err += sn9c102_write_reg(cam, 0x00, 0xC7);
-		err += sn9c102_write_reg(cam, 0x50, 0xC8);
-		err += sn9c102_write_reg(cam, 0x3C, 0xC9);
-		err += sn9c102_write_reg(cam, 0x28, 0xCA);
-		err += sn9c102_write_reg(cam, 0xD8, 0xCB);
-		err += sn9c102_write_reg(cam, 0x14, 0xCC);
-		err += sn9c102_write_reg(cam, 0xEC, 0xCD);
-		err += sn9c102_write_reg(cam, 0x32, 0xCE);
-		err += sn9c102_write_reg(cam, 0xDD, 0xCF);
-		err += sn9c102_write_reg(cam, 0x32, 0xD0);
-		err += sn9c102_write_reg(cam, 0xDD, 0xD1);
-		err += sn9c102_write_reg(cam, 0x6A, 0xD2);
-		err += sn9c102_write_reg(cam, 0x50, 0xD3);
-		err += sn9c102_write_reg(cam, 0x00, 0xD4);
-		err += sn9c102_write_reg(cam, 0x00, 0xD5);
-		err += sn9c102_write_reg(cam, 0x00, 0xD6);
+		err = sn9c102_write_const_regs(cam, {0x44, 0x01}, {0x40, 0x02},
+					       {0x00, 0x03}, {0x1a, 0x04},
+					       {0x44, 0x05}, {0x3e, 0x06},
+					       {0x1a, 0x07}, {0x03, 0x10},
+					       {0x08, 0x14}, {0xa3, 0x17},
+					       {0x4b, 0x18}, {0x00, 0x19},
+					       {0x1d, 0x1a}, {0x10, 0x1b},
+					       {0x02, 0x1c}, {0x03, 0x1d},
+					       {0x0f, 0x1e}, {0x0c, 0x1f},
+					       {0x00, 0x20}, {0x29, 0x21},
+					       {0x40, 0x22}, {0x54, 0x23},
+					       {0x66, 0x24}, {0x76, 0x25},
+					       {0x85, 0x26}, {0x94, 0x27},
+					       {0xa1, 0x28}, {0xae, 0x29},
+					       {0xbb, 0x2a}, {0xc7, 0x2b},
+					       {0xd3, 0x2c}, {0xde, 0x2d},
+					       {0xea, 0x2e}, {0xf4, 0x2f},
+					       {0xff, 0x30}, {0x00, 0x3F},
+					       {0xC7, 0x40}, {0x01, 0x41},
+					       {0x44, 0x42}, {0x00, 0x43},
+					       {0x44, 0x44}, {0x00, 0x45},
+					       {0x44, 0x46}, {0x00, 0x47},
+					       {0xC7, 0x48}, {0x01, 0x49},
+					       {0xC7, 0x4A}, {0x01, 0x4B},
+					       {0xC7, 0x4C}, {0x01, 0x4D},
+					       {0x44, 0x4E}, {0x00, 0x4F},
+					       {0x44, 0x50}, {0x00, 0x51},
+					       {0x44, 0x52}, {0x00, 0x53},
+					       {0xC7, 0x54}, {0x01, 0x55},
+					       {0xC7, 0x56}, {0x01, 0x57},
+					       {0xC7, 0x58}, {0x01, 0x59},
+					       {0x44, 0x5A}, {0x00, 0x5B},
+					       {0x44, 0x5C}, {0x00, 0x5D},
+					       {0x44, 0x5E}, {0x00, 0x5F},
+					       {0xC7, 0x60}, {0x01, 0x61},
+					       {0xC7, 0x62}, {0x01, 0x63},
+					       {0xC7, 0x64}, {0x01, 0x65},
+					       {0x44, 0x66}, {0x00, 0x67},
+					       {0x44, 0x68}, {0x00, 0x69},
+					       {0x44, 0x6A}, {0x00, 0x6B},
+					       {0xC7, 0x6C}, {0x01, 0x6D},
+					       {0xC7, 0x6E}, {0x01, 0x6F},
+					       {0xC7, 0x70}, {0x01, 0x71},
+					       {0x44, 0x72}, {0x00, 0x73},
+					       {0x44, 0x74}, {0x00, 0x75},
+					       {0x44, 0x76}, {0x00, 0x77},
+					       {0xC7, 0x78}, {0x01, 0x79},
+					       {0xC7, 0x7A}, {0x01, 0x7B},
+					       {0xC7, 0x7C}, {0x01, 0x7D},
+					       {0x44, 0x7E}, {0x00, 0x7F},
+					       {0x14, 0x84}, {0x00, 0x85},
+					       {0x27, 0x86}, {0x00, 0x87},
+					       {0x07, 0x88}, {0x00, 0x89},
+					       {0xEC, 0x8A}, {0x0f, 0x8B},
+					       {0xD8, 0x8C}, {0x0f, 0x8D},
+					       {0x3D, 0x8E}, {0x00, 0x8F},
+					       {0x3D, 0x90}, {0x00, 0x91},
+					       {0xCD, 0x92}, {0x0f, 0x93},
+					       {0xf7, 0x94}, {0x0f, 0x95},
+					       {0x0C, 0x96}, {0x00, 0x97},
+					       {0x00, 0x98}, {0x66, 0x99},
+					       {0x05, 0x9A}, {0x00, 0x9B},
+					       {0x04, 0x9C}, {0x00, 0x9D},
+					       {0x08, 0x9E}, {0x00, 0x9F},
+					       {0x2D, 0xC0}, {0x2D, 0xC1},
+					       {0x3A, 0xC2}, {0x05, 0xC3},
+					       {0x04, 0xC4}, {0x3F, 0xC5},
+					       {0x00, 0xC6}, {0x00, 0xC7},
+					       {0x50, 0xC8}, {0x3C, 0xC9},
+					       {0x28, 0xCA}, {0xD8, 0xCB},
+					       {0x14, 0xCC}, {0xEC, 0xCD},
+					       {0x32, 0xCE}, {0xDD, 0xCF},
+					       {0x32, 0xD0}, {0xDD, 0xD1},
+					       {0x6A, 0xD2}, {0x50, 0xD3},
+					       {0x00, 0xD4}, {0x00, 0xD5},
+					       {0x00, 0xD6});
 		break;
 	default:
 		break;
@@ -434,14 +344,12 @@ static struct sn9c102_sensor hv7131r = {
 
 int sn9c102_probe_hv7131r(struct sn9c102_device* cam)
 {
-	int devid, err = 0;
+	int devid, err;
+
+	err = sn9c102_write_const_regs(cam, {0x09, 0x01}, {0x44, 0x02},
+				       {0x34, 0x01}, {0x20, 0x17},
+				       {0x34, 0x01}, {0x46, 0x01});
 
-	err += sn9c102_write_reg(cam, 0x09, 0x01);
-	err += sn9c102_write_reg(cam, 0x44, 0x02);
-	err += sn9c102_write_reg(cam, 0x34, 0x01);
-	err += sn9c102_write_reg(cam, 0x20, 0x17);
-	err += sn9c102_write_reg(cam, 0x34, 0x01);
-	err += sn9c102_write_reg(cam, 0x46, 0x01);
 	if (err)
 		return -EIO;
 
diff --git a/drivers/media/video/sn9c102/sn9c102_mi0343.c b/drivers/media/video/sn9c102/sn9c102_mi0343.c
index 441156d..9200845 100644
--- a/drivers/media/video/sn9c102/sn9c102_mi0343.c
+++ b/drivers/media/video/sn9c102/sn9c102_mi0343.c
@@ -27,13 +27,10 @@ static int mi0343_init(struct sn9c102_device* cam)
 	struct sn9c102_sensor* s = sn9c102_get_sensor(cam);
 	int err = 0;
 
-	err += sn9c102_write_reg(cam, 0x00, 0x10);
-	err += sn9c102_write_reg(cam, 0x00, 0x11);
-	err += sn9c102_write_reg(cam, 0x0a, 0x14);
-	err += sn9c102_write_reg(cam, 0x40, 0x01);
-	err += sn9c102_write_reg(cam, 0x20, 0x17);
-	err += sn9c102_write_reg(cam, 0x07, 0x18);
-	err += sn9c102_write_reg(cam, 0xa0, 0x19);
+	err = sn9c102_write_const_regs(cam, {0x00, 0x10}, {0x00, 0x11},
+				       {0x0a, 0x14}, {0x40, 0x01},
+				       {0x20, 0x17}, {0x07, 0x18},
+				       {0xa0, 0x19});
 
 	err += sn9c102_i2c_try_raw_write(cam, s, 4, s->i2c_slave_id, 0x0d,
 					 0x00, 0x01, 0, 0);
@@ -338,9 +335,9 @@ int sn9c102_probe_mi0343(struct sn9c102_device* cam)
 	u8 data[5+1];
 	int err = 0;
 
-	err += sn9c102_write_reg(cam, 0x01, 0x01);
-	err += sn9c102_write_reg(cam, 0x00, 0x01);
-	err += sn9c102_write_reg(cam, 0x28, 0x17);
+	err = sn9c102_write_const_regs(cam, {0x01, 0x01}, {0x00, 0x01},
+				       {0x28, 0x17});
+
 	if (err)
 		return -EIO;
 
diff --git a/drivers/media/video/sn9c102/sn9c102_mi0360.c b/drivers/media/video/sn9c102/sn9c102_mi0360.c
index 7154dd0..64698ac 100644
--- a/drivers/media/video/sn9c102/sn9c102_mi0360.c
+++ b/drivers/media/video/sn9c102/sn9c102_mi0360.c
@@ -27,34 +27,20 @@ static int mi0360_init(struct sn9c102_device* cam)
 	struct sn9c102_sensor* s = sn9c102_get_sensor(cam);
 	int err = 0;
 
-	err += sn9c102_write_reg(cam, 0x00, 0x10);
-	err += sn9c102_write_reg(cam, 0x00, 0x11);
-	err += sn9c102_write_reg(cam, 0x0a, 0x14);
-	err += sn9c102_write_reg(cam, 0x40, 0x01);
-	err += sn9c102_write_reg(cam, 0x20, 0x17);
-	err += sn9c102_write_reg(cam, 0x07, 0x18);
-	err += sn9c102_write_reg(cam, 0xa0, 0x19);
-	err += sn9c102_write_reg(cam, 0x02, 0x1c);
-	err += sn9c102_write_reg(cam, 0x03, 0x1d);
-	err += sn9c102_write_reg(cam, 0x0f, 0x1e);
-	err += sn9c102_write_reg(cam, 0x0c, 0x1f);
-	err += sn9c102_write_reg(cam, 0x00, 0x20);
-	err += sn9c102_write_reg(cam, 0x10, 0x21);
-	err += sn9c102_write_reg(cam, 0x20, 0x22);
-	err += sn9c102_write_reg(cam, 0x30, 0x23);
-	err += sn9c102_write_reg(cam, 0x40, 0x24);
-	err += sn9c102_write_reg(cam, 0x50, 0x25);
-	err += sn9c102_write_reg(cam, 0x60, 0x26);
-	err += sn9c102_write_reg(cam, 0x70, 0x27);
-	err += sn9c102_write_reg(cam, 0x80, 0x28);
-	err += sn9c102_write_reg(cam, 0x90, 0x29);
-	err += sn9c102_write_reg(cam, 0xa0, 0x2a);
-	err += sn9c102_write_reg(cam, 0xb0, 0x2b);
-	err += sn9c102_write_reg(cam, 0xc0, 0x2c);
-	err += sn9c102_write_reg(cam, 0xd0, 0x2d);
-	err += sn9c102_write_reg(cam, 0xe0, 0x2e);
-	err += sn9c102_write_reg(cam, 0xf0, 0x2f);
-	err += sn9c102_write_reg(cam, 0xff, 0x30);
+	err = sn9c102_write_const_regs(cam, {0x00, 0x10}, {0x00, 0x11},
+				       {0x0a, 0x14}, {0x40, 0x01},
+				       {0x20, 0x17}, {0x07, 0x18},
+				       {0xa0, 0x19}, {0x02, 0x1c},
+				       {0x03, 0x1d}, {0x0f, 0x1e},
+				       {0x0c, 0x1f}, {0x00, 0x20},
+				       {0x10, 0x21}, {0x20, 0x22},
+				       {0x30, 0x23}, {0x40, 0x24},
+				       {0x50, 0x25}, {0x60, 0x26},
+				       {0x70, 0x27}, {0x80, 0x28},
+				       {0x90, 0x29}, {0xa0, 0x2a},
+				       {0xb0, 0x2b}, {0xc0, 0x2c},
+				       {0xd0, 0x2d}, {0xe0, 0x2e},
+				       {0xf0, 0x2f}, {0xff, 0x30});
 
 	err += sn9c102_i2c_try_raw_write(cam, s, 4, s->i2c_slave_id, 0x0d,
 					 0x00, 0x01, 0, 0);
@@ -332,11 +318,10 @@ static struct sn9c102_sensor mi0360 = {
 int sn9c102_probe_mi0360(struct sn9c102_device* cam)
 {
 	u8 data[5+1];
-	int err = 0;
+	int err;
 
-	err += sn9c102_write_reg(cam, 0x01, 0x01);
-	err += sn9c102_write_reg(cam, 0x00, 0x01);
-	err += sn9c102_write_reg(cam, 0x28, 0x17);
+	err = sn9c102_write_const_regs(cam, {0x01, 0x01}, {0x00, 0x01},
+				       {0x28, 0x17});
 	if (err)
 		return -EIO;
 
diff --git a/drivers/media/video/sn9c102/sn9c102_ov7630.c b/drivers/media/video/sn9c102/sn9c102_ov7630.c
index ad9fb2c..31b6080 100644
--- a/drivers/media/video/sn9c102/sn9c102_ov7630.c
+++ b/drivers/media/video/sn9c102/sn9c102_ov7630.c
@@ -29,10 +29,9 @@ static int ov7630_init(struct sn9c102_device* cam)
 	switch (sn9c102_get_bridge(cam)) {
 	case BRIDGE_SN9C101:
 	case BRIDGE_SN9C102:
-		err += sn9c102_write_reg(cam, 0x00, 0x14);
-		err += sn9c102_write_reg(cam, 0x60, 0x17);
-		err += sn9c102_write_reg(cam, 0x0f, 0x18);
-		err += sn9c102_write_reg(cam, 0x50, 0x19);
+		err = sn9c102_write_const_regs(cam, {0x00, 0x14},
+					       {0x60, 0x17}, {0x0f, 0x18},
+					       {0x50, 0x19});
 
 		err += sn9c102_i2c_write(cam, 0x12, 0x8d);
 		err += sn9c102_i2c_write(cam, 0x12, 0x0d);
@@ -62,42 +61,26 @@ static int ov7630_init(struct sn9c102_device* cam)
 		err += sn9c102_i2c_write(cam, 0x71, 0x00);
 		err += sn9c102_i2c_write(cam, 0x74, 0x21);
 		err += sn9c102_i2c_write(cam, 0x7d, 0xf7);
+
 		break;
 	case BRIDGE_SN9C103:
-		err += sn9c102_write_reg(cam, 0x00, 0x02);
-		err += sn9c102_write_reg(cam, 0x00, 0x03);
-		err += sn9c102_write_reg(cam, 0x1a, 0x04);
-		err += sn9c102_write_reg(cam, 0x20, 0x05);
-		err += sn9c102_write_reg(cam, 0x20, 0x06);
-		err += sn9c102_write_reg(cam, 0x20, 0x07);
-		err += sn9c102_write_reg(cam, 0x03, 0x10);
-		err += sn9c102_write_reg(cam, 0x0a, 0x14);
-		err += sn9c102_write_reg(cam, 0x60, 0x17);
-		err += sn9c102_write_reg(cam, 0x0f, 0x18);
-		err += sn9c102_write_reg(cam, 0x50, 0x19);
-		err += sn9c102_write_reg(cam, 0x1d, 0x1a);
-		err += sn9c102_write_reg(cam, 0x10, 0x1b);
-		err += sn9c102_write_reg(cam, 0x02, 0x1c);
-		err += sn9c102_write_reg(cam, 0x03, 0x1d);
-		err += sn9c102_write_reg(cam, 0x0f, 0x1e);
-		err += sn9c102_write_reg(cam, 0x0c, 0x1f);
-		err += sn9c102_write_reg(cam, 0x00, 0x20);
-		err += sn9c102_write_reg(cam, 0x10, 0x21);
-		err += sn9c102_write_reg(cam, 0x20, 0x22);
-		err += sn9c102_write_reg(cam, 0x30, 0x23);
-		err += sn9c102_write_reg(cam, 0x40, 0x24);
-		err += sn9c102_write_reg(cam, 0x50, 0x25);
-		err += sn9c102_write_reg(cam, 0x60, 0x26);
-		err += sn9c102_write_reg(cam, 0x70, 0x27);
-		err += sn9c102_write_reg(cam, 0x80, 0x28);
-		err += sn9c102_write_reg(cam, 0x90, 0x29);
-		err += sn9c102_write_reg(cam, 0xa0, 0x2a);
-		err += sn9c102_write_reg(cam, 0xb0, 0x2b);
-		err += sn9c102_write_reg(cam, 0xc0, 0x2c);
-		err += sn9c102_write_reg(cam, 0xd0, 0x2d);
-		err += sn9c102_write_reg(cam, 0xe0, 0x2e);
-		err += sn9c102_write_reg(cam, 0xf0, 0x2f);
-		err += sn9c102_write_reg(cam, 0xff, 0x30);
+		err = sn9c102_write_const_regs(cam, {0x00, 0x02}, {0x00, 0x03},
+					       {0x1a, 0x04}, {0x20, 0x05},
+					       {0x20, 0x06}, {0x20, 0x07},
+					       {0x03, 0x10}, {0x0a, 0x14},
+					       {0x60, 0x17}, {0x0f, 0x18},
+					       {0x50, 0x19}, {0x1d, 0x1a},
+					       {0x10, 0x1b}, {0x02, 0x1c},
+					       {0x03, 0x1d}, {0x0f, 0x1e},
+					       {0x0c, 0x1f}, {0x00, 0x20},
+					       {0x10, 0x21}, {0x20, 0x22},
+					       {0x30, 0x23}, {0x40, 0x24},
+					       {0x50, 0x25}, {0x60, 0x26},
+					       {0x70, 0x27}, {0x80, 0x28},
+					       {0x90, 0x29}, {0xa0, 0x2a},
+					       {0xb0, 0x2b}, {0xc0, 0x2c},
+					       {0xd0, 0x2d}, {0xe0, 0x2e},
+					       {0xf0, 0x2f}, {0xff, 0x30});
 
 		err += sn9c102_i2c_write(cam, 0x12, 0x8d);
 		err += sn9c102_i2c_write(cam, 0x12, 0x0d);
@@ -425,15 +408,14 @@ int sn9c102_probe_ov7630(struct sn9c102_device* cam)
 	switch (sn9c102_get_bridge(cam)) {
 	case BRIDGE_SN9C101:
 	case BRIDGE_SN9C102:
-		err += sn9c102_write_reg(cam, 0x01, 0x01);
-		err += sn9c102_write_reg(cam, 0x00, 0x01);
-		err += sn9c102_write_reg(cam, 0x28, 0x17);
+		err = sn9c102_write_const_regs(cam, {0x01, 0x01},
+					       {0x00, 0x01}, {0x28, 0x17});
+
 		break;
 	case BRIDGE_SN9C103: /* do _not_ change anything! */
-		err += sn9c102_write_reg(cam, 0x09, 0x01);
-		err += sn9c102_write_reg(cam, 0x42, 0x01);
-		err += sn9c102_write_reg(cam, 0x28, 0x17);
-		err += sn9c102_write_reg(cam, 0x44, 0x02);
+		err = sn9c102_write_const_regs(cam, {0x09, 0x01},
+					       {0x42, 0x01}, {0x28, 0x17},
+					       {0x44, 0x02});
 		pid = sn9c102_i2c_try_read(cam, &ov7630, 0x0a);
 		if (err || pid < 0) { /* try a different initialization */
 			err = sn9c102_write_reg(cam, 0x01, 0x01);
diff --git a/drivers/media/video/sn9c102/sn9c102_ov7660.c b/drivers/media/video/sn9c102/sn9c102_ov7660.c
index eef90ff..c898e948 100644
--- a/drivers/media/video/sn9c102/sn9c102_ov7660.c
+++ b/drivers/media/video/sn9c102/sn9c102_ov7660.c
@@ -26,153 +26,80 @@ static int ov7660_init(struct sn9c102_device* cam)
 {
 	int err = 0;
 
-	err += sn9c102_write_reg(cam, 0x40, 0x02);
-	err += sn9c102_write_reg(cam, 0x00, 0x03);
-	err += sn9c102_write_reg(cam, 0x1a, 0x04);
-	err += sn9c102_write_reg(cam, 0x03, 0x10);
-	err += sn9c102_write_reg(cam, 0x08, 0x14);
-	err += sn9c102_write_reg(cam, 0x20, 0x17);
-	err += sn9c102_write_reg(cam, 0x8b, 0x18);
-	err += sn9c102_write_reg(cam, 0x00, 0x19);
-	err += sn9c102_write_reg(cam, 0x1d, 0x1a);
-	err += sn9c102_write_reg(cam, 0x10, 0x1b);
-	err += sn9c102_write_reg(cam, 0x02, 0x1c);
-	err += sn9c102_write_reg(cam, 0x03, 0x1d);
-	err += sn9c102_write_reg(cam, 0x0f, 0x1e);
-	err += sn9c102_write_reg(cam, 0x0c, 0x1f);
-	err += sn9c102_write_reg(cam, 0x00, 0x20);
-	err += sn9c102_write_reg(cam, 0x29, 0x21);
-	err += sn9c102_write_reg(cam, 0x40, 0x22);
-	err += sn9c102_write_reg(cam, 0x54, 0x23);
-	err += sn9c102_write_reg(cam, 0x66, 0x24);
-	err += sn9c102_write_reg(cam, 0x76, 0x25);
-	err += sn9c102_write_reg(cam, 0x85, 0x26);
-	err += sn9c102_write_reg(cam, 0x94, 0x27);
-	err += sn9c102_write_reg(cam, 0xa1, 0x28);
-	err += sn9c102_write_reg(cam, 0xae, 0x29);
-	err += sn9c102_write_reg(cam, 0xbb, 0x2a);
-	err += sn9c102_write_reg(cam, 0xc7, 0x2b);
-	err += sn9c102_write_reg(cam, 0xd3, 0x2c);
-	err += sn9c102_write_reg(cam, 0xde, 0x2d);
-	err += sn9c102_write_reg(cam, 0xea, 0x2e);
-	err += sn9c102_write_reg(cam, 0xf4, 0x2f);
-	err += sn9c102_write_reg(cam, 0xff, 0x30);
-	err += sn9c102_write_reg(cam, 0x00, 0x3F);
-	err += sn9c102_write_reg(cam, 0xC7, 0x40);
-	err += sn9c102_write_reg(cam, 0x01, 0x41);
-	err += sn9c102_write_reg(cam, 0x44, 0x42);
-	err += sn9c102_write_reg(cam, 0x00, 0x43);
-	err += sn9c102_write_reg(cam, 0x44, 0x44);
-	err += sn9c102_write_reg(cam, 0x00, 0x45);
-	err += sn9c102_write_reg(cam, 0x44, 0x46);
-	err += sn9c102_write_reg(cam, 0x00, 0x47);
-	err += sn9c102_write_reg(cam, 0xC7, 0x48);
-	err += sn9c102_write_reg(cam, 0x01, 0x49);
-	err += sn9c102_write_reg(cam, 0xC7, 0x4A);
-	err += sn9c102_write_reg(cam, 0x01, 0x4B);
-	err += sn9c102_write_reg(cam, 0xC7, 0x4C);
-	err += sn9c102_write_reg(cam, 0x01, 0x4D);
-	err += sn9c102_write_reg(cam, 0x44, 0x4E);
-	err += sn9c102_write_reg(cam, 0x00, 0x4F);
-	err += sn9c102_write_reg(cam, 0x44, 0x50);
-	err += sn9c102_write_reg(cam, 0x00, 0x51);
-	err += sn9c102_write_reg(cam, 0x44, 0x52);
-	err += sn9c102_write_reg(cam, 0x00, 0x53);
-	err += sn9c102_write_reg(cam, 0xC7, 0x54);
-	err += sn9c102_write_reg(cam, 0x01, 0x55);
-	err += sn9c102_write_reg(cam, 0xC7, 0x56);
-	err += sn9c102_write_reg(cam, 0x01, 0x57);
-	err += sn9c102_write_reg(cam, 0xC7, 0x58);
-	err += sn9c102_write_reg(cam, 0x01, 0x59);
-	err += sn9c102_write_reg(cam, 0x44, 0x5A);
-	err += sn9c102_write_reg(cam, 0x00, 0x5B);
-	err += sn9c102_write_reg(cam, 0x44, 0x5C);
-	err += sn9c102_write_reg(cam, 0x00, 0x5D);
-	err += sn9c102_write_reg(cam, 0x44, 0x5E);
-	err += sn9c102_write_reg(cam, 0x00, 0x5F);
-	err += sn9c102_write_reg(cam, 0xC7, 0x60);
-	err += sn9c102_write_reg(cam, 0x01, 0x61);
-	err += sn9c102_write_reg(cam, 0xC7, 0x62);
-	err += sn9c102_write_reg(cam, 0x01, 0x63);
-	err += sn9c102_write_reg(cam, 0xC7, 0x64);
-	err += sn9c102_write_reg(cam, 0x01, 0x65);
-	err += sn9c102_write_reg(cam, 0x44, 0x66);
-	err += sn9c102_write_reg(cam, 0x00, 0x67);
-	err += sn9c102_write_reg(cam, 0x44, 0x68);
-	err += sn9c102_write_reg(cam, 0x00, 0x69);
-	err += sn9c102_write_reg(cam, 0x44, 0x6A);
-	err += sn9c102_write_reg(cam, 0x00, 0x6B);
-	err += sn9c102_write_reg(cam, 0xC7, 0x6C);
-	err += sn9c102_write_reg(cam, 0x01, 0x6D);
-	err += sn9c102_write_reg(cam, 0xC7, 0x6E);
-	err += sn9c102_write_reg(cam, 0x01, 0x6F);
-	err += sn9c102_write_reg(cam, 0xC7, 0x70);
-	err += sn9c102_write_reg(cam, 0x01, 0x71);
-	err += sn9c102_write_reg(cam, 0x44, 0x72);
-	err += sn9c102_write_reg(cam, 0x00, 0x73);
-	err += sn9c102_write_reg(cam, 0x44, 0x74);
-	err += sn9c102_write_reg(cam, 0x00, 0x75);
-	err += sn9c102_write_reg(cam, 0x44, 0x76);
-	err += sn9c102_write_reg(cam, 0x00, 0x77);
-	err += sn9c102_write_reg(cam, 0xC7, 0x78);
-	err += sn9c102_write_reg(cam, 0x01, 0x79);
-	err += sn9c102_write_reg(cam, 0xC7, 0x7A);
-	err += sn9c102_write_reg(cam, 0x01, 0x7B);
-	err += sn9c102_write_reg(cam, 0xC7, 0x7C);
-	err += sn9c102_write_reg(cam, 0x01, 0x7D);
-	err += sn9c102_write_reg(cam, 0x44, 0x7E);
-	err += sn9c102_write_reg(cam, 0x00, 0x7F);
-	err += sn9c102_write_reg(cam, 0x14, 0x84);
-	err += sn9c102_write_reg(cam, 0x00, 0x85);
-	err += sn9c102_write_reg(cam, 0x27, 0x86);
-	err += sn9c102_write_reg(cam, 0x00, 0x87);
-	err += sn9c102_write_reg(cam, 0x07, 0x88);
-	err += sn9c102_write_reg(cam, 0x00, 0x89);
-	err += sn9c102_write_reg(cam, 0xEC, 0x8A);
-	err += sn9c102_write_reg(cam, 0x0f, 0x8B);
-	err += sn9c102_write_reg(cam, 0xD8, 0x8C);
-	err += sn9c102_write_reg(cam, 0x0f, 0x8D);
-	err += sn9c102_write_reg(cam, 0x3D, 0x8E);
-	err += sn9c102_write_reg(cam, 0x00, 0x8F);
-	err += sn9c102_write_reg(cam, 0x3D, 0x90);
-	err += sn9c102_write_reg(cam, 0x00, 0x91);
-	err += sn9c102_write_reg(cam, 0xCD, 0x92);
-	err += sn9c102_write_reg(cam, 0x0f, 0x93);
-	err += sn9c102_write_reg(cam, 0xf7, 0x94);
-	err += sn9c102_write_reg(cam, 0x0f, 0x95);
-	err += sn9c102_write_reg(cam, 0x0C, 0x96);
-	err += sn9c102_write_reg(cam, 0x00, 0x97);
-	err += sn9c102_write_reg(cam, 0x00, 0x98);
-	err += sn9c102_write_reg(cam, 0x66, 0x99);
-	err += sn9c102_write_reg(cam, 0x05, 0x9A);
-	err += sn9c102_write_reg(cam, 0x00, 0x9B);
-	err += sn9c102_write_reg(cam, 0x04, 0x9C);
-	err += sn9c102_write_reg(cam, 0x00, 0x9D);
-	err += sn9c102_write_reg(cam, 0x08, 0x9E);
-	err += sn9c102_write_reg(cam, 0x00, 0x9F);
-	err += sn9c102_write_reg(cam, 0x2D, 0xC0);
-	err += sn9c102_write_reg(cam, 0x2D, 0xC1);
-	err += sn9c102_write_reg(cam, 0x3A, 0xC2);
-	err += sn9c102_write_reg(cam, 0x05, 0xC3);
-	err += sn9c102_write_reg(cam, 0x04, 0xC4);
-	err += sn9c102_write_reg(cam, 0x3F, 0xC5);
-	err += sn9c102_write_reg(cam, 0x00, 0xC6);
-	err += sn9c102_write_reg(cam, 0x00, 0xC7);
-	err += sn9c102_write_reg(cam, 0x50, 0xC8);
-	err += sn9c102_write_reg(cam, 0x3C, 0xC9);
-	err += sn9c102_write_reg(cam, 0x28, 0xCA);
-	err += sn9c102_write_reg(cam, 0xD8, 0xCB);
-	err += sn9c102_write_reg(cam, 0x14, 0xCC);
-	err += sn9c102_write_reg(cam, 0xEC, 0xCD);
-	err += sn9c102_write_reg(cam, 0x32, 0xCE);
-	err += sn9c102_write_reg(cam, 0xDD, 0xCF);
-	err += sn9c102_write_reg(cam, 0x32, 0xD0);
-	err += sn9c102_write_reg(cam, 0xDD, 0xD1);
-	err += sn9c102_write_reg(cam, 0x6A, 0xD2);
-	err += sn9c102_write_reg(cam, 0x50, 0xD3);
-	err += sn9c102_write_reg(cam, 0x00, 0xD4);
-	err += sn9c102_write_reg(cam, 0x00, 0xD5);
-	err += sn9c102_write_reg(cam, 0x00, 0xD6);
+	err = sn9c102_write_const_regs(cam, {0x40, 0x02}, {0x00, 0x03},
+				       {0x1a, 0x04}, {0x03, 0x10},
+				       {0x08, 0x14}, {0x20, 0x17},
+				       {0x8b, 0x18}, {0x00, 0x19},
+				       {0x1d, 0x1a}, {0x10, 0x1b},
+				       {0x02, 0x1c}, {0x03, 0x1d},
+				       {0x0f, 0x1e}, {0x0c, 0x1f},
+				       {0x00, 0x20}, {0x29, 0x21},
+				       {0x40, 0x22}, {0x54, 0x23},
+				       {0x66, 0x24}, {0x76, 0x25},
+				       {0x85, 0x26}, {0x94, 0x27},
+				       {0xa1, 0x28}, {0xae, 0x29},
+				       {0xbb, 0x2a}, {0xc7, 0x2b},
+				       {0xd3, 0x2c}, {0xde, 0x2d},
+				       {0xea, 0x2e}, {0xf4, 0x2f},
+				       {0xff, 0x30}, {0x00, 0x3F},
+				       {0xC7, 0x40}, {0x01, 0x41},
+				       {0x44, 0x42}, {0x00, 0x43},
+				       {0x44, 0x44}, {0x00, 0x45},
+				       {0x44, 0x46}, {0x00, 0x47},
+				       {0xC7, 0x48}, {0x01, 0x49},
+				       {0xC7, 0x4A}, {0x01, 0x4B},
+				       {0xC7, 0x4C}, {0x01, 0x4D},
+				       {0x44, 0x4E}, {0x00, 0x4F},
+				       {0x44, 0x50}, {0x00, 0x51},
+				       {0x44, 0x52}, {0x00, 0x53},
+				       {0xC7, 0x54}, {0x01, 0x55},
+				       {0xC7, 0x56}, {0x01, 0x57},
+				       {0xC7, 0x58}, {0x01, 0x59},
+				       {0x44, 0x5A}, {0x00, 0x5B},
+				       {0x44, 0x5C}, {0x00, 0x5D},
+				       {0x44, 0x5E}, {0x00, 0x5F},
+				       {0xC7, 0x60}, {0x01, 0x61},
+				       {0xC7, 0x62}, {0x01, 0x63},
+				       {0xC7, 0x64}, {0x01, 0x65},
+				       {0x44, 0x66}, {0x00, 0x67},
+				       {0x44, 0x68}, {0x00, 0x69},
+				       {0x44, 0x6A}, {0x00, 0x6B},
+				       {0xC7, 0x6C}, {0x01, 0x6D},
+				       {0xC7, 0x6E}, {0x01, 0x6F},
+				       {0xC7, 0x70}, {0x01, 0x71},
+				       {0x44, 0x72}, {0x00, 0x73},
+				       {0x44, 0x74}, {0x00, 0x75},
+				       {0x44, 0x76}, {0x00, 0x77},
+				       {0xC7, 0x78}, {0x01, 0x79},
+				       {0xC7, 0x7A}, {0x01, 0x7B},
+				       {0xC7, 0x7C}, {0x01, 0x7D},
+				       {0x44, 0x7E}, {0x00, 0x7F},
+				       {0x14, 0x84}, {0x00, 0x85},
+				       {0x27, 0x86}, {0x00, 0x87},
+				       {0x07, 0x88}, {0x00, 0x89},
+				       {0xEC, 0x8A}, {0x0f, 0x8B},
+				       {0xD8, 0x8C}, {0x0f, 0x8D},
+				       {0x3D, 0x8E}, {0x00, 0x8F},
+				       {0x3D, 0x90}, {0x00, 0x91},
+				       {0xCD, 0x92}, {0x0f, 0x93},
+				       {0xf7, 0x94}, {0x0f, 0x95},
+				       {0x0C, 0x96}, {0x00, 0x97},
+				       {0x00, 0x98}, {0x66, 0x99},
+				       {0x05, 0x9A}, {0x00, 0x9B},
+				       {0x04, 0x9C}, {0x00, 0x9D},
+				       {0x08, 0x9E}, {0x00, 0x9F},
+				       {0x2D, 0xC0}, {0x2D, 0xC1},
+				       {0x3A, 0xC2}, {0x05, 0xC3},
+				       {0x04, 0xC4}, {0x3F, 0xC5},
+				       {0x00, 0xC6}, {0x00, 0xC7},
+				       {0x50, 0xC8}, {0x3C, 0xC9},
+				       {0x28, 0xCA}, {0xD8, 0xCB},
+				       {0x14, 0xCC}, {0xEC, 0xCD},
+				       {0x32, 0xCE}, {0xDD, 0xCF},
+				       {0x32, 0xD0}, {0xDD, 0xD1},
+				       {0x6A, 0xD2}, {0x50, 0xD3},
+				       {0x00, 0xD4}, {0x00, 0xD5},
+				       {0x00, 0xD6});
 
 	err += sn9c102_i2c_write(cam, 0x12, 0x80);
 	err += sn9c102_i2c_write(cam, 0x11, 0x09);
@@ -569,13 +496,11 @@ static struct sn9c102_sensor ov7660 = {
 
 int sn9c102_probe_ov7660(struct sn9c102_device* cam)
 {
-	int pid, ver, err = 0;
+	int pid, ver, err;
 
-	err += sn9c102_write_reg(cam, 0x01, 0xf1);
-	err += sn9c102_write_reg(cam, 0x00, 0xf1);
-	err += sn9c102_write_reg(cam, 0x01, 0x01);
-	err += sn9c102_write_reg(cam, 0x00, 0x01);
-	err += sn9c102_write_reg(cam, 0x28, 0x17);
+	err = sn9c102_write_const_regs(cam, {0x01, 0xf1}, {0x00, 0xf1},
+				       {0x01, 0x01}, {0x00, 0x01},
+				       {0x28, 0x17});
 
 	pid = sn9c102_i2c_try_read(cam, &ov7660, 0x0a);
 	ver = sn9c102_i2c_try_read(cam, &ov7660, 0x0b);
diff --git a/drivers/media/video/sn9c102/sn9c102_pas106b.c b/drivers/media/video/sn9c102/sn9c102_pas106b.c
index a670572..6715196 100644
--- a/drivers/media/video/sn9c102/sn9c102_pas106b.c
+++ b/drivers/media/video/sn9c102/sn9c102_pas106b.c
@@ -27,12 +27,9 @@ static int pas106b_init(struct sn9c102_device* cam)
 {
 	int err = 0;
 
-	err += sn9c102_write_reg(cam, 0x00, 0x10);
-	err += sn9c102_write_reg(cam, 0x00, 0x11);
-	err += sn9c102_write_reg(cam, 0x00, 0x14);
-	err += sn9c102_write_reg(cam, 0x20, 0x17);
-	err += sn9c102_write_reg(cam, 0x20, 0x19);
-	err += sn9c102_write_reg(cam, 0x09, 0x18);
+	err = sn9c102_write_const_regs(cam, {0x00, 0x10}, {0x00, 0x11},
+				       {0x00, 0x14}, {0x20, 0x17},
+				       {0x20, 0x19}, {0x09, 0x18});
 
 	err += sn9c102_i2c_write(cam, 0x02, 0x0c);
 	err += sn9c102_i2c_write(cam, 0x05, 0x5a);
@@ -276,16 +273,17 @@ static struct sn9c102_sensor pas106b = {
 
 int sn9c102_probe_pas106b(struct sn9c102_device* cam)
 {
-	int r0 = 0, r1 = 0, err = 0;
+	int r0 = 0, r1 = 0, err;
 	unsigned int pid = 0;
 
 	/*
 	   Minimal initialization to enable the I2C communication
 	   NOTE: do NOT change the values!
 	*/
-	err += sn9c102_write_reg(cam, 0x01, 0x01); /* sensor power down */
-	err += sn9c102_write_reg(cam, 0x00, 0x01); /* sensor power on */
-	err += sn9c102_write_reg(cam, 0x28, 0x17); /* sensor clock at 24 MHz */
+	err = sn9c102_write_const_regs(cam,
+				       {0x01, 0x01}, /* sensor power down */
+				       {0x00, 0x01}, /* sensor power on */
+				       {0x28, 0x17});/* sensor clock 24 MHz */
 	if (err)
 		return -EIO;
 
diff --git a/drivers/media/video/sn9c102/sn9c102_pas202bcb.c b/drivers/media/video/sn9c102/sn9c102_pas202bcb.c
index 4447d7c..c1b8d6b 100644
--- a/drivers/media/video/sn9c102/sn9c102_pas202bcb.c
+++ b/drivers/media/video/sn9c102/sn9c102_pas202bcb.c
@@ -35,47 +35,29 @@ static int pas202bcb_init(struct sn9c102_device* cam)
 	switch (sn9c102_get_bridge(cam)) {
 	case BRIDGE_SN9C101:
 	case BRIDGE_SN9C102:
-		err += sn9c102_write_reg(cam, 0x00, 0x10);
-		err += sn9c102_write_reg(cam, 0x00, 0x11);
-		err += sn9c102_write_reg(cam, 0x00, 0x14);
-		err += sn9c102_write_reg(cam, 0x20, 0x17);
-		err += sn9c102_write_reg(cam, 0x30, 0x19);
-		err += sn9c102_write_reg(cam, 0x09, 0x18);
+		err = sn9c102_write_const_regs(cam, {0x00, 0x10},
+					       {0x00, 0x11}, {0x00, 0x14},
+					       {0x20, 0x17}, {0x30, 0x19},
+					       {0x09, 0x18});
 		break;
 	case BRIDGE_SN9C103:
-		err += sn9c102_write_reg(cam, 0x00, 0x02);
-		err += sn9c102_write_reg(cam, 0x00, 0x03);
-		err += sn9c102_write_reg(cam, 0x1a, 0x04);
-		err += sn9c102_write_reg(cam, 0x20, 0x05);
-		err += sn9c102_write_reg(cam, 0x20, 0x06);
-		err += sn9c102_write_reg(cam, 0x20, 0x07);
-		err += sn9c102_write_reg(cam, 0x00, 0x10);
-		err += sn9c102_write_reg(cam, 0x00, 0x11);
-		err += sn9c102_write_reg(cam, 0x00, 0x14);
-		err += sn9c102_write_reg(cam, 0x20, 0x17);
-		err += sn9c102_write_reg(cam, 0x30, 0x19);
-		err += sn9c102_write_reg(cam, 0x09, 0x18);
-		err += sn9c102_write_reg(cam, 0x02, 0x1c);
-		err += sn9c102_write_reg(cam, 0x03, 0x1d);
-		err += sn9c102_write_reg(cam, 0x0f, 0x1e);
-		err += sn9c102_write_reg(cam, 0x0c, 0x1f);
-		err += sn9c102_write_reg(cam, 0x00, 0x20);
-		err += sn9c102_write_reg(cam, 0x10, 0x21);
-		err += sn9c102_write_reg(cam, 0x20, 0x22);
-		err += sn9c102_write_reg(cam, 0x30, 0x23);
-		err += sn9c102_write_reg(cam, 0x40, 0x24);
-		err += sn9c102_write_reg(cam, 0x50, 0x25);
-		err += sn9c102_write_reg(cam, 0x60, 0x26);
-		err += sn9c102_write_reg(cam, 0x70, 0x27);
-		err += sn9c102_write_reg(cam, 0x80, 0x28);
-		err += sn9c102_write_reg(cam, 0x90, 0x29);
-		err += sn9c102_write_reg(cam, 0xa0, 0x2a);
-		err += sn9c102_write_reg(cam, 0xb0, 0x2b);
-		err += sn9c102_write_reg(cam, 0xc0, 0x2c);
-		err += sn9c102_write_reg(cam, 0xd0, 0x2d);
-		err += sn9c102_write_reg(cam, 0xe0, 0x2e);
-		err += sn9c102_write_reg(cam, 0xf0, 0x2f);
-		err += sn9c102_write_reg(cam, 0xff, 0x30);
+		err = sn9c102_write_const_regs(cam, {0x00, 0x02},
+					       {0x00, 0x03}, {0x1a, 0x04},
+					       {0x20, 0x05}, {0x20, 0x06},
+					       {0x20, 0x07}, {0x00, 0x10},
+					       {0x00, 0x11}, {0x00, 0x14},
+					       {0x20, 0x17}, {0x30, 0x19},
+					       {0x09, 0x18}, {0x02, 0x1c},
+					       {0x03, 0x1d}, {0x0f, 0x1e},
+					       {0x0c, 0x1f}, {0x00, 0x20},
+					       {0x10, 0x21}, {0x20, 0x22},
+					       {0x30, 0x23}, {0x40, 0x24},
+					       {0x50, 0x25}, {0x60, 0x26},
+					       {0x70, 0x27}, {0x80, 0x28},
+					       {0x90, 0x29}, {0xa0, 0x2a},
+					       {0xb0, 0x2b}, {0xc0, 0x2c},
+					       {0xd0, 0x2d}, {0xe0, 0x2e},
+					       {0xf0, 0x2f}, {0xff, 0x30});
 		break;
 	default:
 		break;
@@ -325,15 +307,15 @@ int sn9c102_probe_pas202bcb(struct sn9c102_device* cam)
 	switch (sn9c102_get_bridge(cam)) {
 	case BRIDGE_SN9C101:
 	case BRIDGE_SN9C102:
-		err += sn9c102_write_reg(cam, 0x01, 0x01); /* power down */
-		err += sn9c102_write_reg(cam, 0x40, 0x01); /* power on */
-		err += sn9c102_write_reg(cam, 0x28, 0x17); /* clock 24 MHz */
+		err = sn9c102_write_const_regs(cam,
+					       {0x01, 0x01}, /* power down */
+					       {0x40, 0x01}, /* power on */
+					       {0x28, 0x17});/* clock 24 MHz */
 		break;
 	case BRIDGE_SN9C103: /* do _not_ change anything! */
-		err += sn9c102_write_reg(cam, 0x09, 0x01);
-		err += sn9c102_write_reg(cam, 0x44, 0x01);
-		err += sn9c102_write_reg(cam, 0x44, 0x02);
-		err += sn9c102_write_reg(cam, 0x29, 0x17);
+		err = sn9c102_write_const_regs(cam, {0x09, 0x01},
+					       {0x44, 0x01}, {0x44, 0x02},
+					       {0x29, 0x17});
 		break;
 	default:
 		break;
diff --git a/drivers/media/video/sn9c102/sn9c102_sensor.h b/drivers/media/video/sn9c102/sn9c102_sensor.h
index 05f2942..1bbf64c 100644
--- a/drivers/media/video/sn9c102/sn9c102_sensor.h
+++ b/drivers/media/video/sn9c102/sn9c102_sensor.h
@@ -114,9 +114,17 @@ extern int sn9c102_i2c_write(struct sn9c102_device*, u8 address, u8 value);
 extern int sn9c102_i2c_read(struct sn9c102_device*, u8 address);
 
 /* I/O on registers in the bridge. Could be used by the sensor methods too */
-extern int sn9c102_write_regs(struct sn9c102_device*, u8* buff, u16 index);
-extern int sn9c102_write_reg(struct sn9c102_device*, u8 value, u16 index);
 extern int sn9c102_pread_reg(struct sn9c102_device*, u16 index);
+extern int sn9c102_write_reg(struct sn9c102_device*, u8 value, u16 index);
+extern int sn9c102_write_regs(struct sn9c102_device*, const u8 valreg[][2],
+			      int count);
+/*
+ * Write multiple registers with constant values.  For example:
+ * sn9c102_write_const_regs(cam, {0x00, 0x14}, {0x60, 0x17}, {0x0f, 0x18});
+ */
+#define sn9c102_write_const_regs(device, data...) \
+	({ const static u8 _data[][2] = {data}; \
+	sn9c102_write_regs(device, _data, ARRAY_SIZE(_data)); })
 
 /*****************************************************************************/
 
diff --git a/drivers/media/video/sn9c102/sn9c102_tas5110c1b.c b/drivers/media/video/sn9c102/sn9c102_tas5110c1b.c
index a265767..0e7ec86 100644
--- a/drivers/media/video/sn9c102/sn9c102_tas5110c1b.c
+++ b/drivers/media/video/sn9c102/sn9c102_tas5110c1b.c
@@ -26,14 +26,10 @@ static int tas5110c1b_init(struct sn9c102_device* cam)
 {
 	int err = 0;
 
-	err += sn9c102_write_reg(cam, 0x01, 0x01);
-	err += sn9c102_write_reg(cam, 0x44, 0x01);
-	err += sn9c102_write_reg(cam, 0x00, 0x10);
-	err += sn9c102_write_reg(cam, 0x00, 0x11);
-	err += sn9c102_write_reg(cam, 0x0a, 0x14);
-	err += sn9c102_write_reg(cam, 0x60, 0x17);
-	err += sn9c102_write_reg(cam, 0x06, 0x18);
-	err += sn9c102_write_reg(cam, 0xfb, 0x19);
+	err = sn9c102_write_const_regs(cam, {0x01, 0x01}, {0x44, 0x01},
+				       {0x00, 0x10}, {0x00, 0x11},
+				       {0x0a, 0x14}, {0x60, 0x17},
+				       {0x06, 0x18}, {0xfb, 0x19});
 
 	err += sn9c102_i2c_write(cam, 0xc0, 0x80);
 
diff --git a/drivers/media/video/sn9c102/sn9c102_tas5110d.c b/drivers/media/video/sn9c102/sn9c102_tas5110d.c
index 4681cfa..83a39e8 100644
--- a/drivers/media/video/sn9c102/sn9c102_tas5110d.c
+++ b/drivers/media/video/sn9c102/sn9c102_tas5110d.c
@@ -24,14 +24,11 @@
 
 static int tas5110d_init(struct sn9c102_device* cam)
 {
-	int err = 0;
+	int err;
 
-	err += sn9c102_write_reg(cam, 0x01, 0x01);
-	err += sn9c102_write_reg(cam, 0x04, 0x01);
-	err += sn9c102_write_reg(cam, 0x0a, 0x14);
-	err += sn9c102_write_reg(cam, 0x60, 0x17);
-	err += sn9c102_write_reg(cam, 0x06, 0x18);
-	err += sn9c102_write_reg(cam, 0xfb, 0x19);
+	err = sn9c102_write_const_regs(cam, {0x01, 0x01}, {0x04, 0x01},
+				       {0x0a, 0x14}, {0x60, 0x17},
+				       {0x06, 0x18}, {0xfb, 0x19});
 
 	err += sn9c102_i2c_write(cam, 0x9a, 0xca);
 
diff --git a/drivers/media/video/sn9c102/sn9c102_tas5130d1b.c b/drivers/media/video/sn9c102/sn9c102_tas5130d1b.c
index a7f7113..5040650 100644
--- a/drivers/media/video/sn9c102/sn9c102_tas5130d1b.c
+++ b/drivers/media/video/sn9c102/sn9c102_tas5130d1b.c
@@ -24,16 +24,12 @@
 
 static int tas5130d1b_init(struct sn9c102_device* cam)
 {
-	int err = 0;
+	int err;
 
-	err += sn9c102_write_reg(cam, 0x01, 0x01);
-	err += sn9c102_write_reg(cam, 0x20, 0x17);
-	err += sn9c102_write_reg(cam, 0x04, 0x01);
-	err += sn9c102_write_reg(cam, 0x01, 0x10);
-	err += sn9c102_write_reg(cam, 0x00, 0x11);
-	err += sn9c102_write_reg(cam, 0x00, 0x14);
-	err += sn9c102_write_reg(cam, 0x60, 0x17);
-	err += sn9c102_write_reg(cam, 0x07, 0x18);
+	err = sn9c102_write_const_regs(cam, {0x01, 0x01}, {0x20, 0x17},
+				       {0x04, 0x01}, {0x01, 0x10},
+				       {0x00, 0x11}, {0x00, 0x14},
+				       {0x60, 0x17}, {0x07, 0x18});
 
 	return err;
 }