netdev - Re: [PATCH v2] ptp: add ToD device driver for Intel FPGA cards

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Message-ID: <20230322203320.798a1f77@kernel.org>
Date:   Wed, 22 Mar 2023 20:33:20 -0700
From:   Jakub Kicinski <kuba@...nel.org>
To:     Tianfei Zhang <tianfei.zhang@...el.com>
Cc:     richardcochran@...il.com, netdev@...r.kernel.org,
        linux-fpga@...r.kernel.org, ilpo.jarvinen@...ux.intel.com,
        andriy.shevchenko@...ux.intel.com, vinicius.gomes@...el.com,
        pierre-louis.bossart@...ux.intel.com, marpagan@...hat.com,
        russell.h.weight@...el.com, matthew.gerlach@...ux.intel.com,
        nico@...xnic.net,
        Raghavendra Khadatare <raghavendrax.anand.khadatare@...el.com>
Subject: Re: [PATCH v2] ptp: add ToD device driver for Intel FPGA cards

On Wed, 22 Mar 2023 10:35:47 -0400 Tianfei Zhang wrote:
> + * A fine ToD HW clock offset adjustment. To perform the fine offset adjustment, the
> + * adjust_period and adjust_count argument are used to update the TOD_ADJUST_PERIOD
> + * and TOD_ADJUST_COUNT register for in hardware. The dt->tod_lock spinlock must be
> + * held when calling this function.
> + */
> +static int fine_adjust_tod_clock(struct dfl_tod *dt, u32 adjust_period,
> +				 u32 adjust_count)
> +{
> +	void __iomem *base = dt->tod_ctrl;
> +	u32 val;
> +
> +	writel(adjust_period, base + TOD_ADJUST_PERIOD);
> +	writel(adjust_count, base + TOD_ADJUST_COUNT);
> +
> +	/* Wait for present offset adjustment update to complete */
> +	return readl_poll_timeout_atomic(base + TOD_ADJUST_COUNT, val, !val, TOD_ADJUST_INTERVAL_US,
> +				  TOD_ADJUST_MAX_US);
> +}
> +
> +/*
> + * A coarse ToD HW clock offset adjustment.
> + * The coarse time adjustment performs by adding or subtracting the delta value

You should wrap the code at 80 characters in places 
where it's easily done.