TPM7 input capture on iMX8ULP

[wendy-liu]

Dear all,   

    I want TPM7 channel 2,3,4  to capture other PWM signal.

    I only found input capture demo in SDK_2_16_000_EVK-MIMX8ULP\boards\evkmimx8ulp\driver_examples\tpm.But I can't change DEMO_TPM_BASEADDR(TPM0) to TPM7, cause TPM_INTERRUPT_NUMBER does not support TPM7.

    What should I do?Is my solution feasible?

    Looking forward to your reply!

[Zhiming_Liu]

Hello,

The TPM7 is designed in A35 domain, so we didn't test it before in M33 at least in the SDK source code.

If you want to assign the TPM7 in M33, you need:

1. add correct XRDC settings to assign Pbridge4->TPM7 from A35 to M33

2. set PCC4->TPM7 clock

3.use correct IRQ number.

To give M33 access to Pbridge4->TPM7 and PCC4.

struct xrdc_pac_msc_config imx8ulp_pdac[] = {
	{ 0, PAC_SLOT_ALL, {0, 7, 0, 0, 0, 0, 0, 7} }, /* PAC0 */
	{ 0, 44, {0, 7, 7, 0, 0, 0, 0, 7} }, /* PAC0 slot 44 for CGC1 */
	{ 0, 36, {0, 0, 0, 0, 0, 0, 7, 7} }, /* PAC0 slot 36 for CMC1 */
	{ 0, 41, {0, 0, 0, 0, 0, 0, 7, 7} }, /* PAC0 slot 41 for SIM_AD */
	{ 1, PAC_SLOT_ALL, {0, 7, 0, 0, 0, 0, 0, 7} }, /* PAC1 */
	{ 1, 0, {0, 7, 7, 0, 0, 0, 7, 7} }, /* PAC1 slot 0 for PCC4 */
	{ 1, 6, {0, 7, 7, 0, 0, 0, 0, 7} }, /* PAC1 slot 6 for LPUART6 */
	{ 1, 7, {0, 7, 7, 0, 0, 0, 0, 7} }, /* PAC1 slot 7 for LPUART7 */
	{ 1, 9,  {0, 7, 7, 7, 0, 0, 0, 7} }, /* SAI5 for HIFI4 and eDMA2 */
	{ 1, 12, {0, 7, 7, 0, 0, 0, 7, 7} }, /* PAC1 slot 12 for IOMUXC1 */
{ 1, 3, {0, 7, 7, 0, 0, 0, 7, 7} }/* PAC1 slot 3 for TPM7----------------------->M33 */
	{ 2, PAC_SLOT_ALL, {7, 7, 7, 7, 0, 0, 7, 7} }, /* PAC2 */
};

But for the TPM7 interrupt, this is deigned in GIC(A35 domain),  i need to double check if you can use it in SDK.

Best Regards,
Zhiming

[wendy-liu]

Thanks for replying!

I want to confirm that  input capture feature can only be used on the M33 core, right?

[Zhiming_Liu]

Hello,

If you want to use TPM input capture in Linux, the default driver can't support that. 

But you can modify the drivers/clocksource/timer-imx-tpm.c to support it referring the RM.

As the RM describes how to use input capture mode:

Best Regards,
Zhiming

[wendy-liu]

Hello！

    Thank you very much!! I will read this charter carefully!