[PATCH v4 1/6] media: qcom: camss: factor out the VFE minimum clock rate

[Atanas Filipov]

vfe_set_clock_rates() and vfe_check_clock_rates() both compute the
minimum clock rate needed by the VFE lines from their pixel rates,
inside the loop over the VFE clocks. The result is the same for every
clock.

Move the computation into vfe_get_min_clock_rate() and call it once
per VFE, so that the clock loops only select and check rates. No
functional change.

Signed-off-by: Atanas Filipov <atanas.filipov@xxxxxxxxxxxxxxxx>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
---
 drivers/media/platform/qcom/camss/camss-vfe.c | 108 ++++++++----------
 1 file changed, 46 insertions(+), 62 deletions(-)

diff --git a/drivers/media/platform/qcom/camss/camss-vfe.c b/drivers/media/platform/qcom/camss/camss-vfe.c
index 2680a9914765..59be37f83df3 100644
--- a/drivers/media/platform/qcom/camss/camss-vfe.c
+++ b/drivers/media/platform/qcom/camss/camss-vfe.c
@@ -935,52 +935,66 @@ static bool vfe_check_clock_levels(struct camss_clock *clock)
 }
 
 /*
- * vfe_set_clock_rates - Calculate and set clock rates on VFE module
+ * vfe_get_min_clock_rate - Get the minimum VFE clock rate for its lines
  * @vfe: VFE device
  *
- * Return 0 on success or a negative error code otherwise
+ * Return the highest rate needed by the VFE lines for their pixel rates,
+ * including the clock margin, or 0 if no pixel rate is available
  */
-static int vfe_set_clock_rates(struct vfe_device *vfe)
+static u64 vfe_get_min_clock_rate(struct vfe_device *vfe)
 {
-	struct device *dev = vfe->camss->dev;
 	u64 pixel_clock[VFE_LINE_NUM_MAX];
-	int i, j;
-	int ret;
+	u64 min_rate = 0;
+	int i;
 
 	for (i = VFE_LINE_RDI0; i < vfe->res->line_num; i++) {
-		ret = camss_get_pixel_clock(&vfe->line[i].subdev.entity,
-					    &pixel_clock[i]);
-		if (ret)
+		if (camss_get_pixel_clock(&vfe->line[i].subdev.entity,
+					  &pixel_clock[i]))
 			pixel_clock[i] = 0;
 	}
 
-	for (i = 0; i < vfe->nclocks; i++) {
-		struct camss_clock *clock = &vfe->clock[i];
+	for (i = VFE_LINE_RDI0; i < vfe->res->line_num; i++) {
+		u32 tmp;
+		u8 bpp;
 
-		if (vfe_match_clock_names(vfe, clock) && vfe_check_clock_levels(clock)) {
-			u64 min_rate = 0;
-			long rate;
+		if (i == VFE_LINE_PIX) {
+			tmp = pixel_clock[i];
+		} else {
+			struct vfe_line *l = &vfe->line[i];
 
-			for (j = VFE_LINE_RDI0; j < vfe->res->line_num; j++) {
-				u32 tmp;
-				u8 bpp;
+			bpp = camss_format_get_bpp(l->formats,
+						   l->nformats,
+						   l->fmt[MSM_VFE_PAD_SINK].code);
+			tmp = pixel_clock[i] * bpp / 64;
+		}
 
-				if (j == VFE_LINE_PIX) {
-					tmp = pixel_clock[j];
-				} else {
-					struct vfe_line *l = &vfe->line[j];
+		if (min_rate < tmp)
+			min_rate = tmp;
+	}
 
-					bpp = camss_format_get_bpp(l->formats,
-								   l->nformats,
-								   l->fmt[MSM_VFE_PAD_SINK].code);
-					tmp = pixel_clock[j] * bpp / 64;
-				}
+	camss_add_clock_margin(&min_rate);
 
-				if (min_rate < tmp)
-					min_rate = tmp;
-			}
+	return min_rate;
+}
 
-			camss_add_clock_margin(&min_rate);
+/*
+ * vfe_set_clock_rates - Calculate and set clock rates on VFE module
+ * @vfe: VFE device
+ *
+ * Return 0 on success or a negative error code otherwise
+ */
+static int vfe_set_clock_rates(struct vfe_device *vfe)
+{
+	struct device *dev = vfe->camss->dev;
+	u64 min_rate = vfe_get_min_clock_rate(vfe);
+	int i, j;
+	int ret;
+
+	for (i = 0; i < vfe->nclocks; i++) {
+		struct camss_clock *clock = &vfe->clock[i];
+
+		if (vfe_match_clock_names(vfe, clock) && vfe_check_clock_levels(clock)) {
+			long rate;
 
 			for (j = 0; j < clock->nfreqs; j++)
 				if (min_rate < clock->freq[j])
@@ -1024,45 +1038,15 @@ static int vfe_set_clock_rates(struct vfe_device *vfe)
  */
 static int vfe_check_clock_rates(struct vfe_device *vfe)
 {
-	u64 pixel_clock[VFE_LINE_NUM_MAX];
-	int i, j;
-	int ret;
-
-	for (i = VFE_LINE_RDI0; i < vfe->res->line_num; i++) {
-		ret = camss_get_pixel_clock(&vfe->line[i].subdev.entity,
-					    &pixel_clock[i]);
-		if (ret)
-			pixel_clock[i] = 0;
-	}
+	u64 min_rate = vfe_get_min_clock_rate(vfe);
+	int i;
 
 	for (i = 0; i < vfe->nclocks; i++) {
 		struct camss_clock *clock = &vfe->clock[i];
 
 		if (vfe_match_clock_names(vfe, clock) && vfe_check_clock_levels(clock)) {
-			u64 min_rate = 0;
 			unsigned long rate;
 
-			for (j = VFE_LINE_RDI0; j < vfe->res->line_num; j++) {
-				u32 tmp;
-				u8 bpp;
-
-				if (j == VFE_LINE_PIX) {
-					tmp = pixel_clock[j];
-				} else {
-					struct vfe_line *l = &vfe->line[j];
-
-					bpp = camss_format_get_bpp(l->formats,
-								   l->nformats,
-								   l->fmt[MSM_VFE_PAD_SINK].code);
-					tmp = pixel_clock[j] * bpp / 64;
-				}
-
-				if (min_rate < tmp)
-					min_rate = tmp;
-			}
-
-			camss_add_clock_margin(&min_rate);
-
 			rate = clk_get_rate(clock->clk);
 			if (rate < min_rate)
 				return -EBUSY;
-- 
2.34.1