From c680dd603857d7218b84751e9f6f0654bbfbefa2 Mon Sep 17 00:00:00 2001 From: Trent Piepho Date: Wed, 4 Apr 2007 17:11:04 -0300 Subject: 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 Signed-off-by: Trent Piepho Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/sn9c102/sn9c102_tas5130d1b.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) (limited to 'drivers/media/video/sn9c102/sn9c102_tas5130d1b.c') diff --git a/drivers/media/video/sn9c102/sn9c102_tas5130d1b.c b/drivers/media/video/sn9c102/sn9c102_tas5130d1b.c index a7f711396152..50406503fc40 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; } -- cgit v1.2.1