diff options
| author | Trent Piepho <xyzzy@speakeasy.org> | 2007-04-04 17:11:04 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2007-04-27 15:45:27 -0300 |
| commit | c680dd603857d7218b84751e9f6f0654bbfbefa2 (patch) | |
| tree | 58ce390afc6bc720a57550a2171aa1af9a4b7df9 /drivers/media/video/sn9c102/sn9c102_pas106b.c | |
| parent | 0ee32871c18a3662d8958a8e9998eb4d2ae94159 (diff) | |
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>
Diffstat (limited to 'drivers/media/video/sn9c102/sn9c102_pas106b.c')
| -rw-r--r-- | drivers/media/video/sn9c102/sn9c102_pas106b.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/drivers/media/video/sn9c102/sn9c102_pas106b.c b/drivers/media/video/sn9c102/sn9c102_pas106b.c index a67057210cab..67151964801f 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; |