When a USB device is connected to the USB host port on the SAM9N12 then
you get "-62" error which seems to indicate USB replies from the device
are timing out. Looking around, I saw the USB bus was running at half
speed. Going further, it seems that in ..._set_rate() the PLL wasn't
actually being adjusted. Writing the multiplier and divider values to
the peripheral fixes the bus running at half speed.
Signed-off-by: Marcin Ziemianowicz <marcin@xxxxxxxxxxxxxxxx>
---
drivers/clk/at91/clk-pll.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/clk/at91/clk-pll.c b/drivers/clk/at91/clk-pll.c
index 534961766ae5..db7155fe9346 100644
--- a/drivers/clk/at91/clk-pll.c
+++ b/drivers/clk/at91/clk-pll.c
@@ -288,6 +288,14 @@ static int clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
pll->div = div;
pll->mul = mul;
+ // Set the PLL as per above div and mil values.
+ regmap_update_bits(pll->regmap, AT91_CKGR_PLLBR,
+ AT91_PMC_DIV | AT91_PMC_MUL,
+ (div << 0) | (mul << 16));
+
+ pr_debug("clk-pll: setting new rate, (%lu hz / %u) * %u = %lu hz\n",
+ parent_rate, div, mul, rate);
+
return 0;
}
--
2.17.0
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