AM5729: I2C Programming developing a PRU driver

Pierrick Rauby

Part Number: AM5729
Other Parts Discussed in Thread: PRU-CGT

Hi All,

I am trying to develop a PRU driver for I2C on the AM5729. I have some questions about the setup procedure using Interrupt and polling (I am not using DMA). I am not quite sure about the differences between the setup described between section 24.1.5.1.1.1.1 and 24.1.5.1.1.1.2) and the figure (24.19).

1- What value should be used to configure the I2C_IRQENABLE_SET? I have tried with 0x1f (enable XRDY, RRDY, ARDY, NACK, and AL as they are used later). However, I receive a Kernel Oops when I try to run my code " [Feb26 14:54] Unable to handle kernel NULL pointer dereference at virtual address 00000000

[ +0.003725] Internal error: Oops: 5 [#1] PREEMPT SMP ARM

genirq: exiting task "irq/114-4807a00" (110) is an active IRQ thread (irq 114)"

2- I have tried to write in the I2C_DATA register but reading the register after always gives 0xD. I have checked the value of I2C_IRQSTATUS_RAW, and it always read 0x10 (XRDY). Am I missing something to write the data?

If you want to have a look at my code, it is under this repository https://github.com/PierrickRauby/BBAI-PRU-I2C/blob/main/am572x_pru_i2c_driver.pru1_1.c

Thanks for any help you can provide!

Pierrick

over 4 years ago

0 Vineet Roy over 4 years ago

TI__Mastermind 37435 points

Hi,

Which SDK version are you using ? Is this on Beaglebone AI ?

>I am not quite sure about the differences between the setup described between section 24.1.5.1.1.1.1 and 24.1.5.1.1.1.2) and the figure (24.19).

TI : Which document are you referencing ? Please mention

>What value should be used to configure the I2C_IRQENABLE_SET? I have tried with 0x1f (enable XRDY, RRDY, ARDY, NACK, and AL as they are used later). However, I receive a Kernel Oops when I try to run my code " [Feb26 14:54] Unable to handle kernel NULL pointer dereference at virtual address 00000000

TI : Are you referencing some public code ? Please provide the link.

Regards

Vineet

0 Pierrick Rauby over 4 years ago in reply to Vineet Roy

Prodigy 90 points

Hi Vineet,

> Which SDK version are you using? Is this on Beaglebone AI?

I am using the Beaglebone AI, and I compile the PRU codes on the board using the PRU-CGT compiler.

> TI: Which document are you referencing? Please mention

Whoa sorry, I forgot to mention that I was talking about the AM572x TRM SPRUHZ6L

> TI: Are you referencing some public code? Please provide the link.

The code I was referencing is the am572x_pru_i2c_driver.pru1_1.c code in the Github that I have linked in my original post. (https://github.com/PierrickRauby/BBAI-PRU-I2C/blob/main/am572x_pru_i2c_driver.pru1_1.c

+1 Vineet Roy over 4 years ago

TI__Mastermind 37435 points

Hi Pierrick,

Re-opening this thread after some time. Apologies.

Is this issue still open ?

Regards

Vineet

0 Pierrick Rauby over 4 years ago

Prodigy 90 points

Hi Vineet,

Sorry for the late answer. I believe I got it to work even if I am not quite sure about the test o the ARDY bit on figure 24-25 (but I have open another thread about that and I think it got solved)

Regards,

Pierrick

0 Vineet Roy over 4 years ago in reply to Pierrick Rauby

TI__Mastermind 37435 points

Thanks for confirming, I will close this

Regards

Vineet

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AM5729: I2C Programming developing a PRU driver