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authorTony Lindgren <tony@atomide.com>2014-07-29 04:03:30 -0700
committerTony Lindgren <tony@atomide.com>2014-07-29 04:03:30 -0700
commitd40dbcd57b942528d7dbd17ace0b32136d848ecb (patch)
tree2a37983629948ff3086ad1d13d6d1612afa8478a /arch/arm
parent3965f5ba0489c01f419216c8909965b9a6a39388 (diff)
parent0a26344440b5f9940c99112fdc3804f073b1f5a7 (diff)
downloadop-kernel-dev-d40dbcd57b942528d7dbd17ace0b32136d848ecb.zip
op-kernel-dev-d40dbcd57b942528d7dbd17ace0b32136d848ecb.tar.gz
Merge tag 'for-v3.17/omap-clock-b' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v3.17/soc
Modify OMAP PLL rate rounding function to round to the exact rate requested or the next one below it. This is intended to resolve some DSS problems. Basic build, boot, and PM test results are available here: http://www.pwsan.com/omap/testlogs/clock-b-v3.17/20140725061121/
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/mach-omap2/clkt_dpll.c28
-rw-r--r--arch/arm/mach-omap2/dpll3xxx.c13
2 files changed, 32 insertions, 9 deletions
diff --git a/arch/arm/mach-omap2/clkt_dpll.c b/arch/arm/mach-omap2/clkt_dpll.c
index 3c34df0..950308f 100644
--- a/arch/arm/mach-omap2/clkt_dpll.c
+++ b/arch/arm/mach-omap2/clkt_dpll.c
@@ -285,10 +285,13 @@ long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate,
{
struct clk_hw_omap *clk = to_clk_hw_omap(hw);
int m, n, r, scaled_max_m;
+ int min_delta_m = INT_MAX, min_delta_n = INT_MAX;
unsigned long scaled_rt_rp;
unsigned long new_rate = 0;
struct dpll_data *dd;
unsigned long ref_rate;
+ long delta;
+ long prev_min_delta = LONG_MAX;
const char *clk_name;
if (!clk || !clk->dpll_data)
@@ -334,23 +337,34 @@ long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate,
if (r == DPLL_MULT_UNDERFLOW)
continue;
+ /* skip rates above our target rate */
+ delta = target_rate - new_rate;
+ if (delta < 0)
+ continue;
+
+ if (delta < prev_min_delta) {
+ prev_min_delta = delta;
+ min_delta_m = m;
+ min_delta_n = n;
+ }
+
pr_debug("clock: %s: m = %d: n = %d: new_rate = %lu\n",
clk_name, m, n, new_rate);
- if (target_rate == new_rate) {
- dd->last_rounded_m = m;
- dd->last_rounded_n = n;
- dd->last_rounded_rate = target_rate;
+ if (delta == 0)
break;
- }
}
- if (target_rate != new_rate) {
+ if (prev_min_delta == LONG_MAX) {
pr_debug("clock: %s: cannot round to rate %lu\n",
clk_name, target_rate);
return ~0;
}
- return target_rate;
+ dd->last_rounded_m = min_delta_m;
+ dd->last_rounded_n = min_delta_n;
+ dd->last_rounded_rate = target_rate - prev_min_delta;
+
+ return dd->last_rounded_rate;
}
diff --git a/arch/arm/mach-omap2/dpll3xxx.c b/arch/arm/mach-omap2/dpll3xxx.c
index cd5f3a0..ac3d789 100644
--- a/arch/arm/mach-omap2/dpll3xxx.c
+++ b/arch/arm/mach-omap2/dpll3xxx.c
@@ -475,6 +475,7 @@ int omap3_noncore_dpll_set_rate(struct clk_hw *hw, unsigned long rate,
{
struct clk_hw_omap *clk = to_clk_hw_omap(hw);
struct clk *new_parent = NULL;
+ unsigned long rrate;
u16 freqsel = 0;
struct dpll_data *dd;
int ret;
@@ -502,8 +503,16 @@ int omap3_noncore_dpll_set_rate(struct clk_hw *hw, unsigned long rate,
__clk_prepare(dd->clk_ref);
clk_enable(dd->clk_ref);
- if (dd->last_rounded_rate != rate)
- rate = __clk_round_rate(hw->clk, rate);
+ /* XXX this check is probably pointless in the CCF context */
+ if (dd->last_rounded_rate != rate) {
+ rrate = __clk_round_rate(hw->clk, rate);
+ if (rrate != rate) {
+ pr_warn("%s: %s: final rate %lu does not match desired rate %lu\n",
+ __func__, __clk_get_name(hw->clk),
+ rrate, rate);
+ rate = rrate;
+ }
+ }
if (dd->last_rounded_rate == 0)
return -EINVAL;
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