On Friday 02 December 2016 02:35 PM, Keerthy wrote:
Currently the divider selection logic blindly divides the parent_rate
by the clk rate and gives the divider value for the divider clocks
which do not have the CLK_SET_RATE_PARENT flag set. Add the clk divider
table parsing to get the closest divider available in the table
provided via Device tree.
The code is pretty much taken from: drivers/clk/clk-divider.c.
and used here to fix up the best divider selection logic.
A gentle ping on this patch. This applies cleanly on the next branch as
on today. Let me know if this needs to be rebased.
- Keerthy
Signed-off-by: Keerthy <j-keerthy@xxxxxx>
Reported-by: Richard Woodruff <r-woodruff2@xxxxxx>
---
drivers/clk/ti/divider.c | 31 ++++++++++++++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/ti/divider.c b/drivers/clk/ti/divider.c
index b4e5de1..6bb8778 100644
--- a/drivers/clk/ti/divider.c
+++ b/drivers/clk/ti/divider.c
@@ -140,6 +140,35 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
return true;
}
+static int _div_round_up(const struct clk_div_table *table,
+ unsigned long parent_rate, unsigned long rate)
+{
+ const struct clk_div_table *clkt;
+ int up = INT_MAX;
+ int div = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
+
+ for (clkt = table; clkt->div; clkt++) {
+ if (clkt->div == div)
+ return clkt->div;
+ else if (clkt->div < div)
+ continue;
+
+ if ((clkt->div - div) < (up - div))
+ up = clkt->div;
+ }
+
+ return up;
+}
+
+static int _div_round(const struct clk_div_table *table,
+ unsigned long parent_rate, unsigned long rate)
+{
+ if (!table)
+ return DIV_ROUND_UP(parent_rate, rate);
+
+ return _div_round_up(table, parent_rate, rate);
+}
+
static int ti_clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
unsigned long *best_parent_rate)
{
@@ -155,7 +184,7 @@ static int ti_clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
parent_rate = *best_parent_rate;
- bestdiv = DIV_ROUND_UP(parent_rate, rate);
+ bestdiv = _div_round(divider->table, parent_rate, rate);
bestdiv = bestdiv == 0 ? 1 : bestdiv;
bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
return bestdiv;
--
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