From d898692e9ddb223210ab9a6e99d58b1fff9658a0 Mon Sep 17 00:00:00 2001 From: Janusz Krzysztofik Date: Sun, 13 Oct 2019 09:50:47 -0300 Subject: [PATCH] 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 Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- drivers/media/i2c/ov6650.c | 29 +++++------------------------ 1 file 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;