* [PATCH 1/5] clk: meson: Fix an issue with inaccurate hifi_pll frequency
@ 2024-09-04 7:20 chuan.liu
2024-09-04 7:32 ` Chuan Liu
0 siblings, 1 reply; 4+ messages in thread
From: chuan.liu @ 2024-09-04 7:20 UTC (permalink / raw)
To: chuan.liu, xianwei.zhao
Cc: linux-amlogic, linux-clk, linux-arm-kernel, linux-kernel
From: Chuan Liu <chuan.liu@amlogic.com>
Some PLLs with fractional multipliers have fractional denominators that
are fixed to "100000" instead of the previous "(1 << pll->frac.width)".
The hifi_pll for both C3 and S4 supports a fractional multiplier and has
a fixed fractional denominator of "100000".
Here are the results of the C3-based command tests (already defined
CLOCK_ALLOW_WRITE_DEBUGFS):
# echo 491520000 > /sys/kernel/debug/clk/hifi_pll/clk_rate
# cat /sys/kernel/debug/clk/hifi_pll/clk_rate
491520000
# echo 1 > /sys/kernel/debug/clk/hifi_pll/clk_prepare_enable
# cat /sys/kernel/debug/meson-clk-msr/clks/hifi_pll_clk
491515625 +/-15625Hz
# devmem 0xfe008100 32
0xD00304A3
# devmem 0xfe008104 32
0x00014820
Based on the register information read above, it can be obtained:
m = 0xA3 = 0d163;
n = 0x1 = 0d1
frac = 0x14820 = 0d84000
od = 0x3 = 0d3
hifi_pll calculates the output frequency:
calc_rate = xtal_rate / n * (m + (frac / frac_max)) >> od;
calc_rate = 24000000 / 1 * (163 + (84000 / 100000)) >> 3;
calc_rate = 491520000
clk_rate, msr_rate, and calc_rate all match.
The test and calculation results of S4 are consistent with those of C3,
which will not be repeated here.
To: Neil Armstrong <neil.armstrong@linaro.org>
To: Jerome Brunet <jbrunet@baylibre.com>
To: Michael Turquette <mturquette@baylibre.com>
To: Stephen Boyd <sboyd@kernel.org>
To: Kevin Hilman <khilman@baylibre.com>
To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: <linux-amlogic@lists.infradead.org>
Cc: <linux-clk@vger.kernel.org>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Chuan Liu <chuan.liu@amlogic.com>
--- b4-submit-tracking ---
# This section is used internally by b4 prep for tracking purposes.
{
"series": {
"revision": 1,
"change-id": "20240904-fix_clk-668f7a1a2b16",
"prefixes": []
}
}
--
2.42.0
_______________________________________________
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linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 1/5] clk: meson: Fix an issue with inaccurate hifi_pll frequency
2024-09-04 7:20 [PATCH 1/5] clk: meson: Fix an issue with inaccurate hifi_pll frequency chuan.liu
@ 2024-09-04 7:32 ` Chuan Liu
0 siblings, 0 replies; 4+ messages in thread
From: Chuan Liu @ 2024-09-04 7:32 UTC (permalink / raw)
To: xianwei.zhao; +Cc: linux-amlogic, linux-clk, linux-arm-kernel, linux-kernel
Sorry, The email was sent by mistake, please ignore it.
On 2024/9/4 15:20, chuan.liu@amlogic.com wrote:
> From: Chuan Liu <chuan.liu@amlogic.com>
>
> Some PLLs with fractional multipliers have fractional denominators that
> are fixed to "100000" instead of the previous "(1 << pll->frac.width)".
>
> The hifi_pll for both C3 and S4 supports a fractional multiplier and has
> a fixed fractional denominator of "100000".
>
> Here are the results of the C3-based command tests (already defined
> CLOCK_ALLOW_WRITE_DEBUGFS):
> # echo 491520000 > /sys/kernel/debug/clk/hifi_pll/clk_rate
> # cat /sys/kernel/debug/clk/hifi_pll/clk_rate
> 491520000
> # echo 1 > /sys/kernel/debug/clk/hifi_pll/clk_prepare_enable
> # cat /sys/kernel/debug/meson-clk-msr/clks/hifi_pll_clk
> 491515625 +/-15625Hz
> # devmem 0xfe008100 32
> 0xD00304A3
> # devmem 0xfe008104 32
> 0x00014820
>
> Based on the register information read above, it can be obtained:
> m = 0xA3 = 0d163;
> n = 0x1 = 0d1
> frac = 0x14820 = 0d84000
> od = 0x3 = 0d3
>
> hifi_pll calculates the output frequency:
> calc_rate = xtal_rate / n * (m + (frac / frac_max)) >> od;
> calc_rate = 24000000 / 1 * (163 + (84000 / 100000)) >> 3;
> calc_rate = 491520000
>
> clk_rate, msr_rate, and calc_rate all match.
>
> The test and calculation results of S4 are consistent with those of C3,
> which will not be repeated here.
>
> To: Neil Armstrong <neil.armstrong@linaro.org>
> To: Jerome Brunet <jbrunet@baylibre.com>
> To: Michael Turquette <mturquette@baylibre.com>
> To: Stephen Boyd <sboyd@kernel.org>
> To: Kevin Hilman <khilman@baylibre.com>
> To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> Cc: <linux-amlogic@lists.infradead.org>
> Cc: <linux-clk@vger.kernel.org>
> Cc: <linux-arm-kernel@lists.infradead.org>
> Cc: <linux-kernel@vger.kernel.org>
> Signed-off-by: Chuan Liu <chuan.liu@amlogic.com>
>
>
> --- b4-submit-tracking ---
> # This section is used internally by b4 prep for tracking purposes.
> {
> "series": {
> "revision": 1,
> "change-id": "20240904-fix_clk-668f7a1a2b16",
> "prefixes": []
> }
> }
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 1/5] clk: meson: Fix an issue with inaccurate hifi_pll frequency
@ 2024-09-04 7:18 chuan.liu
2024-09-04 7:31 ` Chuan Liu
0 siblings, 1 reply; 4+ messages in thread
From: chuan.liu @ 2024-09-04 7:18 UTC (permalink / raw)
To: chuan.liu; +Cc: linux-amlogic, linux-clk, linux-arm-kernel, linux-kernel
From: Chuan Liu <chuan.liu@amlogic.com>
Some PLLs with fractional multipliers have fractional denominators that
are fixed to "100000" instead of the previous "(1 << pll->frac.width)".
The hifi_pll for both C3 and S4 supports a fractional multiplier and has
a fixed fractional denominator of "100000".
Here are the results of the C3-based command tests (already defined
CLOCK_ALLOW_WRITE_DEBUGFS):
# echo 491520000 > /sys/kernel/debug/clk/hifi_pll/clk_rate
# cat /sys/kernel/debug/clk/hifi_pll/clk_rate
491520000
# echo 1 > /sys/kernel/debug/clk/hifi_pll/clk_prepare_enable
# cat /sys/kernel/debug/meson-clk-msr/clks/hifi_pll_clk
491515625 +/-15625Hz
# devmem 0xfe008100 32
0xD00304A3
# devmem 0xfe008104 32
0x00014820
Based on the register information read above, it can be obtained:
m = 0xA3 = 0d163;
n = 0x1 = 0d1
frac = 0x14820 = 0d84000
od = 0x3 = 0d3
hifi_pll calculates the output frequency:
calc_rate = xtal_rate / n * (m + (frac / frac_max)) >> od;
calc_rate = 24000000 / 1 * (163 + (84000 / 100000)) >> 3;
calc_rate = 491520000
clk_rate, msr_rate, and calc_rate all match.
The test and calculation results of S4 are consistent with those of C3,
which will not be repeated here.
To: Neil Armstrong <neil.armstrong@linaro.org>
To: Jerome Brunet <jbrunet@baylibre.com>
To: Michael Turquette <mturquette@baylibre.com>
To: Stephen Boyd <sboyd@kernel.org>
To: Kevin Hilman <khilman@baylibre.com>
To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: <linux-amlogic@lists.infradead.org>
Cc: <linux-clk@vger.kernel.org>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Chuan Liu <chuan.liu@amlogic.com>
--- b4-submit-tracking ---
# This section is used internally by b4 prep for tracking purposes.
{
"series": {
"revision": 1,
"change-id": "20240904-fix_clk-668f7a1a2b16",
"prefixes": []
}
}
--
2.42.0
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 1/5] clk: meson: Fix an issue with inaccurate hifi_pll frequency
2024-09-04 7:18 chuan.liu
@ 2024-09-04 7:31 ` Chuan Liu
0 siblings, 0 replies; 4+ messages in thread
From: Chuan Liu @ 2024-09-04 7:31 UTC (permalink / raw)
Cc: linux-amlogic, linux-clk, linux-arm-kernel, linux-kernel
Sorry, The email was sent by mistake, please ignore it.
On 2024/9/4 15:18, chuan.liu@amlogic.com wrote:
> From: Chuan Liu <chuan.liu@amlogic.com>
>
> Some PLLs with fractional multipliers have fractional denominators that
> are fixed to "100000" instead of the previous "(1 << pll->frac.width)".
>
> The hifi_pll for both C3 and S4 supports a fractional multiplier and has
> a fixed fractional denominator of "100000".
>
> Here are the results of the C3-based command tests (already defined
> CLOCK_ALLOW_WRITE_DEBUGFS):
> # echo 491520000 > /sys/kernel/debug/clk/hifi_pll/clk_rate
> # cat /sys/kernel/debug/clk/hifi_pll/clk_rate
> 491520000
> # echo 1 > /sys/kernel/debug/clk/hifi_pll/clk_prepare_enable
> # cat /sys/kernel/debug/meson-clk-msr/clks/hifi_pll_clk
> 491515625 +/-15625Hz
> # devmem 0xfe008100 32
> 0xD00304A3
> # devmem 0xfe008104 32
> 0x00014820
>
> Based on the register information read above, it can be obtained:
> m = 0xA3 = 0d163;
> n = 0x1 = 0d1
> frac = 0x14820 = 0d84000
> od = 0x3 = 0d3
>
> hifi_pll calculates the output frequency:
> calc_rate = xtal_rate / n * (m + (frac / frac_max)) >> od;
> calc_rate = 24000000 / 1 * (163 + (84000 / 100000)) >> 3;
> calc_rate = 491520000
>
> clk_rate, msr_rate, and calc_rate all match.
>
> The test and calculation results of S4 are consistent with those of C3,
> which will not be repeated here.
>
> To: Neil Armstrong <neil.armstrong@linaro.org>
> To: Jerome Brunet <jbrunet@baylibre.com>
> To: Michael Turquette <mturquette@baylibre.com>
> To: Stephen Boyd <sboyd@kernel.org>
> To: Kevin Hilman <khilman@baylibre.com>
> To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> Cc: <linux-amlogic@lists.infradead.org>
> Cc: <linux-clk@vger.kernel.org>
> Cc: <linux-arm-kernel@lists.infradead.org>
> Cc: <linux-kernel@vger.kernel.org>
> Signed-off-by: Chuan Liu <chuan.liu@amlogic.com>
>
>
> --- b4-submit-tracking ---
> # This section is used internally by b4 prep for tracking purposes.
> {
> "series": {
> "revision": 1,
> "change-id": "20240904-fix_clk-668f7a1a2b16",
> "prefixes": []
> }
> }
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
^ permalink raw reply [flat|nested] 4+ messages in thread
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2024-09-04 7:20 [PATCH 1/5] clk: meson: Fix an issue with inaccurate hifi_pll frequency chuan.liu
2024-09-04 7:32 ` Chuan Liu
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2024-09-04 7:18 chuan.liu
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