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boards: arm: stm32g081b_eval: Add UCPD1 peripherals to dts node

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The STM32G081b has two UCPD peripherals. This commit adds UCPD1
to the DTS so both peripherals can be used.

Signed-off-by: Sam Hurst <sbh1187@gmail.com>
This commit is contained in:
Sam Hurst 2022-12-14 11:24:57 -08:00 • committed by Carles Cufí
commit d71e59bee9
1 changed files with 31 additions and 0 deletions
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31
boards/arm/stm32g081b_eval/stm32g081b_eval.dts
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@ -132,6 +132,37 @@
};
};
&ucpd1 {
status = "okay";
/*
* UCPD is fed directly from HSI which is @ 16MHz. The ucpd_clk goes to
* a prescaler who's output feeds the 'half-bit' divider which is used
* to generate clock for delay counters and BMC Rx/Tx blocks. The rx is
* designed to work in freq ranges of 6 <--> 18 MHz, however recommended
* range is 9 <--> 18 MHz.
*
* +-------+ @ 16 MHz +-------+ @ ~600 kHz +-----------+
* HSI ---->| /psc |--------->| /hbit |--------------->| trans_cnt |
* +-------+ +-------+ | +-----------+
* | +-----------+
* +----------->| ifrgap_cnt|
* +-----------+
* Requirements:
* 1. hbit_clk ~= 600 kHz: 16 MHz / 600 kHz = 26.67
* 2. tTransitionWindow - 12 to 20 uSec
* 3. tInterframGap - uSec
*
* hbit_clk = HSI_clk / 27 = 592.6 kHz = 1.687 uSec period
* tTransitionWindow = 1.687 uS * 8 = 13.5 uS
* tInterFrameGap = 1.687 uS * 17 = 28.68 uS
*/
psc-ucpdclk = <1>;
hbitclkdiv = <27>;
pinctrl-0 = <&ucpd1_cc1_pa8 &ucpd1_cc2_pb15>;
pinctrl-names = "default";
};
&ucpd2 {
status = "okay";