[PATCH 2/2] ARM: OMAP2+: fix dpll round_rate() to actually round
From: Tomi Valkeinen <hidden>
Date: 2014-01-17 07:44:59
Also in:
linux-omap
Subsystem:
arm port, omap2+ support, the rest · Maintainers:
Russell King, Aaro Koskinen, Andreas Kemnade, Kevin Hilman, Roger Quadros, Tony Lindgren, Linus Torvalds
omap2_dpll_round_rate() doesn't actually round the given rate, even if the name and the description so hints. Instead it only tries to find an exact rate match, or if that fails, return ~0 as an error. What this basically means is that the user of the clock needs to know what rates the dpll can support, which obviously isn't right. This patch adds a simple method of rounding: during the iteration, the code keeps track of the closest rate match. If no exact match is found, the closest is returned. Signed-off-by: Tomi Valkeinen <redacted> --- arch/arm/mach-omap2/clkt_dpll.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/arch/arm/mach-omap2/clkt_dpll.c b/arch/arm/mach-omap2/clkt_dpll.c
index 1f1708ef77bb..1b4e68dfb713 100644
--- a/arch/arm/mach-omap2/clkt_dpll.c
+++ b/arch/arm/mach-omap2/clkt_dpll.c@@ -298,6 +298,7 @@ long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate, struct dpll_data *dd; unsigned long ref_rate; const char *clk_name; + unsigned long diff, closest_diff = ~0; if (!clk || !clk->dpll_data) return ~0;
@@ -345,20 +346,26 @@ long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate, pr_debug("clock: %s: m = %d: n = %d: new_rate = %lu\n", clk_name, m, n, new_rate); - if (target_rate == new_rate) { + diff = max(target_rate, new_rate) - min(target_rate, new_rate); + + if (diff < closest_diff) { + closest_diff = diff; + dd->last_rounded_m = m; dd->last_rounded_n = n; - dd->last_rounded_rate = target_rate; - break; + dd->last_rounded_rate = new_rate; + + if (diff == 0) + break; } } - if (target_rate != new_rate) { + if (closest_diff == ~0) { pr_debug("clock: %s: cannot round to rate %lu\n", clk_name, target_rate); return ~0; } - return target_rate; + return dd->last_rounded_rate; }
--
1.8.3.2