Commit 7c1c5413 authored by Scott Wood's avatar Scott Wood Committed by Stephen Boyd

clk: qoriq: Don't allow CPU clocks higher than starting value

The boot-time frequency of a CPU is considered its rated maximum, as we
have no other source of such information.  However, this was previously
only used for chips with 80% restrictions on secondary PLLs.  This
usually wasn't a problem because most chips/configs boot with a divider
of /1, with other dividers being used only for dynamic frequency
reduction.  However, at least one config (LS1021A at less than 1 GHz)
uses a different divider for top speed.  This was causing cpufreq to set
a frequency beyond the chip's rated speed.

This is fixed by applying a 100%-of-initial-speed limit to all CPU PLLs,
similar to the existing 80% limit that only applied to some.
Signed-off-by: default avatarScott Wood <>
Signed-off-by: default avatarStephen Boyd <>
parent c7129375
......@@ -700,6 +700,7 @@ static struct clk * __init create_mux_common(struct clockgen *cg,
struct mux_hwclock *hwc,
const struct clk_ops *ops,
unsigned long min_rate,
unsigned long max_rate,
unsigned long pct80_rate,
const char *fmt, int idx)
......@@ -728,6 +729,8 @@ static struct clk * __init create_mux_common(struct clockgen *cg,
if (rate < min_rate)
if (rate > max_rate)
parent_names[j] = div->name;
hwc->parent_to_clksel[j] = i;
......@@ -759,7 +762,7 @@ static struct clk * __init create_one_cmux(struct clockgen *cg, int idx)
struct mux_hwclock *hwc;
const struct clockgen_pll_div *div;
unsigned long plat_rate, min_rate;
u64 pct80_rate;
u64 max_rate, pct80_rate;
u32 clksel;
hwc = kzalloc(sizeof(*hwc), GFP_KERNEL);
......@@ -787,8 +790,8 @@ static struct clk * __init create_one_cmux(struct clockgen *cg, int idx)
return NULL;
pct80_rate = clk_get_rate(div->clk);
pct80_rate *= 8;
max_rate = clk_get_rate(div->clk);
pct80_rate = max_rate * 8;
do_div(pct80_rate, 10);
plat_rate = clk_get_rate(cg->pll[PLATFORM_PLL].div[PLL_DIV1].clk);
......@@ -798,7 +801,7 @@ static struct clk * __init create_one_cmux(struct clockgen *cg, int idx)
min_rate = plat_rate / 2;
return create_mux_common(cg, hwc, &cmux_ops, min_rate,
return create_mux_common(cg, hwc, &cmux_ops, min_rate, max_rate,
pct80_rate, "cg-cmux%d", idx);
......@@ -813,7 +816,7 @@ static struct clk * __init create_one_hwaccel(struct clockgen *cg, int idx)
hwc->reg = cg->regs + 0x20 * idx + 0x10;
hwc->info = cg->info.hwaccel[idx];
return create_mux_common(cg, hwc, &hwaccel_ops, 0, 0,
return create_mux_common(cg, hwc, &hwaccel_ops, 0, ULONG_MAX, 0,
"cg-hwaccel%d", idx);
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