TDA4VM: TDA4VM-clk output

Katherine Wang

Intellectual 2210 points

Part Number: TDA4VM

Hi Team,

I want to use the following pins to generate a 500K

clock.

https://software-dl.ti.com/tisci/esd/latest/5_soc_doc/j721e/clocks.html

I checked clk and ran it, but there was no waveform output.

The dts is as follows:

elmos@0 {
pinctrl-names = "default";
pinctrl-0 = <&spi_e521_clkref_pins_default>;
spi-max-frequency = <2000000>;
reg = <0>;
compatible = "elmos,e521.42";
clocks = <&k3_clks 157 82>;
clock-names = "elmos";
};

code:

ref_clk = devm_clk_get(&spi->dev,"elmos");

ret = clk_prepare_enable(ref_clk);

dev_dbg(&spi->dev, "elmosclk_prepare_enable ret%d\n",ret);

The results of the pinmux detection were as follows (mode 2):

But there was no waveform output to the corresponding pin.

over 3 years ago

0 Katherine Wang over 3 years ago

TI__Intellectual 2210 points

cat /sys/kernel/debug/clk/clk_summary

enable prepare protect duty
clock count count count rate accuracy phase cycle
---------------------------------------------------------------------------------------------

clk:157:82 1 1 0 0 0 0 50000

0 Katherine Wang over 3 years ago

TI__Intellectual 2210 points

It didn’t work even though I switched to the mode 0.

0 Katherine Wang over 3 years ago

TI__Intellectual 2210 points

It didn't work either, even though this was increased.

0 Katherine Wang over 3 years ago

TI__Intellectual 2210 points

Hello,

Is this a PWM pin?

ecap0_in_apwm_ou

Can I set it as a PWM one? If so, how can I set the output as 500k?

Kind regards,

Katherine

0 Katherine Wang over 3 years ago

TI__Intellectual 2210 points

Hello,

Could you please follow up on my question?

Regards,

Katherine

0 Katherine Wang over 3 years ago in reply to Katherine Wang

TI__Intellectual 2210 points

Katherine Wang said:
Is this a PWM pin?

ecap0_in_apwm_ou

Yes, it can be exported from this module, but it seems the registers of the operation module may crash.

They will also crash under the read-only mode. We are using SDK 7.3 for the time being. We tried in Linux and U-boot, and the same thing happened.

0 Katherine Wang over 3 years ago

TI__Intellectual 2210 points

Katherine Wang said:
Can I set it as a PWM one? If so, how can I set the output as 500k?

Yes, as above, to generate a PWM output, a 500K square wave would be enough.

0 Katherine Wang over 3 years ago

TI__Intellectual 2210 points

Hi Team,

The code written by us plus:

+ power-domains = <&k3_pds 80 TI_SCI_PD_EXCLUSIVE>;

pm_runtime_enable(&pdev->dev);
ret = pm_runtime_get(&pdev->dev);
if (ret < 0) {
pm_runtime_put_noidle(&pdev->dev);

return ret;
}

The registers of the operation module didn’t crash again for the time being.

We operated on the registers and followed the trm example but did not generate the corresponding waveform.

reg_writel(pcap,ECAP_ECCTL,reg_readl(pcap,ECAP_ECCTL) | EC_APWM_MODE<<25);
reg_writel(pcap,ECAP_CAP1,1200);
reg_writel(pcap,ECAP_CNTPHS,0x0);
reg_writel(pcap,ECAP_ECCTL,0x0);
reg_writel(pcap,ECAP_ECCTL,reg_readl(pcap,ECAP_ECCTL)&(~(1<<26)));
reg_writel(pcap,ECAP_ECCTL,reg_readl(pcap,ECAP_ECCTL)&(~(1<<21)));
reg_writel(pcap,ECAP_ECCTL,reg_readl(pcap,ECAP_ECCTL)&(~(EC_SYNCO_DIS<<22)));
reg_writel(pcap,ECAP_ECCTL,reg_readl(pcap,ECAP_ECCTL) | 1<<20);
reg_writel(pcap,ECAP_CAP2,0x300);

Could you please tell me how to operate on the ecap0 register so that the “ecap0_in_apwm_out” can have a 500K output?

Kind regards,

Katherine

0 Keerthy J over 3 years ago in reply to Katherine Wang

TI__Guru**** 166970 points

Katherine,

Apologies for the long delay. Could you use ehrpwm instance on the SoC to generate waveform?

If not could you clearly explain the requirement and code changes you have done thus far?

Best Regards,

Keerthy

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TDA4VM: TDA4VM-clk output