Subject: Re: [PATCH net-next v4 1/1] ptp: clockmatrix: support 32-bit address space

From: Rahul Rameshbabu <[email-masked]>
Date: Wed, 22 Nov 2023 10:33:50 -0800

On Wed, 15 Nov, 2023 10:10:53 -0500 Min Li <[email-masked]> wrote:
> From: Min Li <[email-masked]>
>
> We used to assume 0x2010xxxx address. Now that
> we need to access 0x2011xxxx address, we need
> to support read/write the whole 32-bit address space.
>
> Signed-off-by: Min Li <[email-masked]>
> ---
> - Drop MAX_ABS_WRITE_PHASE_PICOSECONDS advised by Rahul
> - Apply SCSR_ADDR to scrach register in idtcm_load_firmware advised by Simon
> - Apply u32 to base in idtcm_output_enable advised by Simon
> - Correct sync_ctrl0/1 parameter position for idtcm_write advised by Simon
>
>  drivers/ptp/ptp_clockmatrix.c    |  71 ++--
>  drivers/ptp/ptp_clockmatrix.h    |  32 +-
>  include/linux/mfd/idt8a340_reg.h | 542 ++++++++++++++++---------------
>  3 files changed, 331 insertions(+), 314 deletions(-)
>
> diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c
> index f6f9d4adce04..1d5da77502e6 100644
> --- a/drivers/ptp/ptp_clockmatrix.c
> +++ b/drivers/ptp/ptp_clockmatrix.c

<snip>

> @@ -1705,7 +1720,7 @@ static s32 idtcm_getmaxphase(struct ptp_clock_info *ptp __always_unused)
>  }
>  
>  /*
> - * Internal function for implementing support for write phase offset
> + * Maximum absolute value for write phase offset in picoseconds

This documentation comment is wrong (this is meant for
idtcm_getmaxphase). I think you might be generating patches without
rebasing on the latest net-next tree?

>   *
>   * @channel:  channel
>   * @delta_ns: delta in nanoseconds
> @@ -1717,6 +1732,7 @@ static int _idtcm_adjphase(struct idtcm_channel *channel, s32 delta_ns)
>  	u8 i;
>  	u8 buf[4] = {0};
>  	s32 phase_50ps;
> +	s64 offset_ps;
>  
>  	if (channel->mode != PTP_PLL_MODE_WRITE_PHASE) {
>  		err = channel->configure_write_phase(channel);
> @@ -1724,7 +1740,8 @@ static int _idtcm_adjphase(struct idtcm_channel *channel, s32 delta_ns)
>  			return err;
>  	}
>  
> -	phase_50ps = div_s64((s64)delta_ns * 1000, 50);
> +	offset_ps = (s64)delta_ns * 1000;
> +	phase_50ps = div_s64(offset_ps, 50);

Sorry, I am not sure what this change has to do with 32-bit address
space support. Seems like this was introduced due to not rebasing
properly on top of latest changes?

>  
>  	for (i = 0; i < 4; i++) {
>  		buf[i] = phase_50ps & 0xff;

<snip>

--
Thanks,

Rahul Rameshbabu