@@ -67,11 +67,11 @@ static unsigned long sun4i_tmds_calc_divider(unsigned long rate,
static int sun4i_tmds_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
- struct clk_hw *parent;
+ struct clk_hw *parent = NULL;
unsigned long best_parent = 0;
unsigned long rate = req->rate;
int best_div = 1, best_half = 1;
- int i, j;
+ int i, j, p;
/*
* We only consider PLL3, since the TCON is very likely to be
@@ -79,32 +79,37 @@ static int sun4i_tmds_determine_rate(struct clk_hw *hw,
* clock, so we should not need to do anything.
*/
- parent = clk_hw_get_parent_by_index(hw, 0);
- if (!parent)
- return -EINVAL;
-
- for (i = 1; i < 3; i++) {
- for (j = 1; j < 16; j++) {
- unsigned long ideal = rate * i * j;
- unsigned long rounded;
-
- rounded = clk_hw_round_rate(parent, ideal);
-
- if (rounded == ideal) {
- best_parent = rounded;
- best_half = i;
- best_div = j;
- goto out;
- }
-
- if (abs(rate - rounded / i) <
- abs(rate - best_parent / best_div)) {
- best_parent = rounded;
- best_div = i;
+ for (p = 0; p < clk_hw_get_num_parents(hw); p++) {
+ parent = clk_hw_get_parent_by_index(hw, p);
+ if (!parent)
+ continue;
+
+ for (i = 1; i < 3; i++) {
+ for (j = 1; j < 16; j++) {
+ unsigned long ideal = rate * i * j;
+ unsigned long rounded;
+
+ rounded = clk_hw_round_rate(parent, ideal);
+
+ if (rounded == ideal) {
+ best_parent = rounded;
+ best_half = i;
+ best_div = j;
+ goto out;
+ }
+
+ if (abs(rate - rounded / i) <
+ abs(rate - best_parent / best_div)) {
+ best_parent = rounded;
+ best_div = i;
+ }
}
}
}
+ if (!parent)
+ return -EINVAL;
+
out:
req->rate = best_parent / best_half / best_div;
req->best_parent_rate = best_parent;
Allwinner SoCs typically have two PLLs reserved for video related usage. At the moment we only support using the first one to feed the HDMI transmitter block's TMDS clock. Let the HDMI encoder's TMDS clock go through all of its parents when calculating possible clock rates. This allows usage of the second video PLL as its parent. Note that this does not handle conflicting pixel clocks. It is entirely possible to have an LCD panel use one pixel clock rate, only to be overridden by the HDMI transmitter's clock rate request when the second display pipeline is enabled. This should be handled by having all the clock drivers honor clock rate ranges, and have the consumers use clk_set_rate_min/clk_set_rate_max. Signed-off-by: Chen-Yu Tsai <wens@csie.org> --- drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c | 53 ++++++++++++++++------------- 1 file changed, 29 insertions(+), 24 deletions(-)