Thread (8 messages) 8 messages, 2 authors, 2019-06-14
STALE2597d
Revisions (5)
  1. v1 [diff vs current]
  2. v2 current
  3. v3 [diff vs current]
  4. v4 [diff vs current]
  5. v4 [diff vs current]

[PATCH v2 2/6] clk: rockchip: fix up the frac clk get rate error

From: Elaine Zhang <hidden>
Date: 2019-05-16 07:29:27
Also in: linux-clk, linux-rockchip, lkml
Subsystem: arm/rockchip soc support, common clk framework, the rest · Maintainers: Heiko Stuebner, Michael Turquette, Stephen Boyd, Linus Torvalds

support fractional divider with only one level parent clock

Signed-off-by: Elaine Zhang <redacted>
---
 drivers/clk/rockchip/clk.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
index e04bf300ea0a..0256a99f06f3 100644
--- a/drivers/clk/rockchip/clk.c
+++ b/drivers/clk/rockchip/clk.c
@@ -195,16 +195,21 @@ static void rockchip_fractional_approximation(struct clk_hw *hw,
 	if (((rate * 20 > p_rate) && (p_rate % rate != 0)) ||
 	    (fd->max_prate && fd->max_prate < p_rate)) {
 		p_parent = clk_hw_get_parent(clk_hw_get_parent(hw));
-		p_parent_rate = clk_hw_get_rate(p_parent);
-		*parent_rate = p_parent_rate;
-		if (fd->max_prate && p_parent_rate > fd->max_prate) {
-			div = DIV_ROUND_UP(p_parent_rate, fd->max_prate);
-			*parent_rate = p_parent_rate / div;
+		if (!p_parent) {
+			*parent_rate = p_rate;
+		} else {
+			p_parent_rate = clk_hw_get_rate(p_parent);
+			*parent_rate = p_parent_rate;
+			if (fd->max_prate && p_parent_rate > fd->max_prate) {
+				div = DIV_ROUND_UP(p_parent_rate,
+						   fd->max_prate);
+				*parent_rate = p_parent_rate / div;
+			}
 		}
 
 		if (*parent_rate < rate * 20) {
-			pr_err("%s parent_rate(%ld) is low than rate(%ld)*20, fractional div is not allowed\n",
-			       clk_hw_get_name(hw), *parent_rate, rate);
+			pr_warn("%s p_rate(%ld) is low than rate(%ld)*20, use integer or half-div\n",
+				clk_hw_get_name(hw), *parent_rate, rate);
 			*m = 0;
 			*n = 1;
 			return;
-- 
1.9.1




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