summaryrefslogtreecommitdiff
path: root/drivers/media/i2c
diff options
context:
space:
mode:
authorJanusz Krzysztofik <jmkrzyszt@gmail.com>2019-10-13 09:50:47 -0300
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-10-24 18:39:41 -0300
commitd898692e9ddb223210ab9a6e99d58b1fff9658a0 (patch)
tree7f485cc855158ef621e0742911f6f5c4efbac20a /drivers/media/i2c
parentb1c5794382208c455c4e511c3f0b55565b69dd53 (diff)
media: ov6650: Simplify clock divisor calculation
As appears from an analysis of to_clkrc() helper code after its pclk_limit argument has been dropped, its result no longer depends on another argument - pclk_max. Moreover, assuming that a constant value of FRAME_RATE_MAX is always used as a denominator of the only significant argument left - a struct v4l2_fract, the result in fact depends only on the numerator value of that argument. As a further consequence, it no longer makes sense to recalculate frame intervals by converting them forth and back with a GET_CLKRC_DIV(to_clkrc(tpf)) construct. Drop use of GET_CLKRC_DIV() on results of to_clkrc() where possible - use the frame interval value directly. Furthermore, replace the to_clkrc() helper function with a simple macro and update its users to always use FRAME_RATE_MAX as frame interval denominator and pass only its numerator as an argument. Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'drivers/media/i2c')
-rw-r--r--drivers/media/i2c/ov6650.c29
1 files changed, 5 insertions, 24 deletions
diff --git a/drivers/media/i2c/ov6650.c b/drivers/media/i2c/ov6650.c
index a50244401491..61ddd4ea4c26 100644
--- a/drivers/media/i2c/ov6650.c
+++ b/drivers/media/i2c/ov6650.c
@@ -545,18 +545,7 @@ static bool is_unscaled_ok(int width, int height, struct v4l2_rect *rect)
return width > rect->width >> 1 || height > rect->height >> 1;
}
-static u8 to_clkrc(struct v4l2_fract *timeperframe, unsigned long pclk_max)
-{
- unsigned long pclk;
-
- if (timeperframe->numerator && timeperframe->denominator)
- pclk = pclk_max * timeperframe->denominator /
- (FRAME_RATE_MAX * timeperframe->numerator);
- else
- pclk = pclk_max;
-
- return (pclk_max - 1) / pclk;
-}
+#define to_clkrc(div) ((div) - 1)
/* set the format we will capture in */
static int ov6650_s_fmt(struct v4l2_subdev *sd, struct v4l2_mbus_framefmt *mf)
@@ -650,7 +639,7 @@ static int ov6650_s_fmt(struct v4l2_subdev *sd, struct v4l2_mbus_framefmt *mf)
mclk = 12000000;
dev_dbg(&client->dev, "using 12MHz input clock\n");
- clkrc |= to_clkrc(&priv->tpf, priv->pclk_max);
+ clkrc |= to_clkrc(priv->tpf.numerator);
pclk = priv->pclk_max / GET_CLKRC_DIV(clkrc);
dev_dbg(&client->dev, "pixel clock divider: %ld.%ld\n",
@@ -749,9 +738,7 @@ static int ov6650_g_frame_interval(struct v4l2_subdev *sd,
struct i2c_client *client = v4l2_get_subdevdata(sd);
struct ov6650 *priv = to_ov6650(client);
- ival->interval.numerator = GET_CLKRC_DIV(to_clkrc(&priv->tpf,
- priv->pclk_max));
- ival->interval.denominator = FRAME_RATE_MAX;
+ ival->interval = priv->tpf;
dev_dbg(&client->dev, "Frame interval: %u/%u s\n",
ival->interval.numerator, ival->interval.denominator);
@@ -766,7 +753,6 @@ static int ov6650_s_frame_interval(struct v4l2_subdev *sd,
struct ov6650 *priv = to_ov6650(client);
struct v4l2_fract *tpf = &ival->interval;
int div, ret;
- u8 clkrc;
if (tpf->numerator == 0 || tpf->denominator == 0)
div = 1; /* Reset to full rate */
@@ -778,14 +764,9 @@ static int ov6650_s_frame_interval(struct v4l2_subdev *sd,
else if (div > GET_CLKRC_DIV(CLKRC_DIV_MASK))
div = GET_CLKRC_DIV(CLKRC_DIV_MASK);
- tpf->numerator = div;
- tpf->denominator = FRAME_RATE_MAX;
-
- clkrc = to_clkrc(tpf, priv->pclk_max);
-
- ret = ov6650_reg_rmw(client, REG_CLKRC, clkrc, CLKRC_DIV_MASK);
+ ret = ov6650_reg_rmw(client, REG_CLKRC, to_clkrc(div), CLKRC_DIV_MASK);
if (!ret) {
- priv->tpf.numerator = GET_CLKRC_DIV(clkrc);
+ priv->tpf.numerator = div;
priv->tpf.denominator = FRAME_RATE_MAX;
*tpf = priv->tpf;