netdev - Re: [PATCH v2 07/13] net: ethernet: ti: cpts: rework initialization/deinitialization

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Date:   Tue, 29 Nov 2016 11:07:37 +0100
From:   Richard Cochran <richardcochran@...il.com>
To:     Grygorii Strashko <grygorii.strashko@...com>
Cc:     "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
        Mugunthan V N <mugunthanvnm@...com>,
        Sekhar Nori <nsekhar@...com>, linux-kernel@...r.kernel.org,
        linux-omap@...r.kernel.org, Rob Herring <robh+dt@...nel.org>,
        devicetree@...r.kernel.org, Murali Karicheri <m-karicheri2@...com>,
        Wingman Kwok <w-kwok2@...com>
Subject: Re: [PATCH  v2 07/13] net: ethernet: ti: cpts: rework
 initialization/deinitialization

On Mon, Nov 28, 2016 at 05:03:31PM -0600, Grygorii Strashko wrote:
> +int cpts_register(struct cpts *cpts)
>  {
>  	int err, i;
>  
> -	cpts->info = cpts_info;
> -	spin_lock_init(&cpts->lock);
> -
> -	cpts->cc.read = cpts_systim_read;
> -	cpts->cc.mask = CLOCKSOURCE_MASK(32);
> -	cpts->cc_mult = mult;
> -	cpts->cc.mult = mult;
> -	cpts->cc.shift = shift;
> -
>  	INIT_LIST_HEAD(&cpts->events);
>  	INIT_LIST_HEAD(&cpts->pool);
>  	for (i = 0; i < CPTS_MAX_EVENTS; i++)
>  		list_add(&cpts->pool_data[i].list, &cpts->pool);
>  
> -	cpts_clk_init(dev, cpts);
> +	clk_enable(cpts->refclk);
> +
>  	cpts_write32(cpts, CPTS_EN, control);
>  	cpts_write32(cpts, TS_PEND_EN, int_enable);
>  
> +	cpts->cc.mult = cpts->cc_mult;

It is not clear why you set cc.mult in a different place than
cc.shift.  That isn't logical, but maybe later patches make it
clear...

>  	timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real()));
>  
> -	INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check);
> -
> -	cpts->clock = ptp_clock_register(&cpts->info, dev);
> +	cpts->clock = ptp_clock_register(&cpts->info, cpts->dev);
>  	if (IS_ERR(cpts->clock)) {
>  		err = PTR_ERR(cpts->clock);
>  		cpts->clock = NULL;
> @@ -392,26 +364,74 @@ int cpts_register(struct device *dev, struct cpts *cpts,
>  	return 0;
>  
>  err_ptp:
> -	if (cpts->refclk)
> -		cpts_clk_release(cpts);
> +	clk_disable(cpts->refclk);
>  	return err;
>  }
>  EXPORT_SYMBOL_GPL(cpts_register);
>  
>  void cpts_unregister(struct cpts *cpts)
>  {
> -	if (cpts->clock) {
> -		ptp_clock_unregister(cpts->clock);
> -		cancel_delayed_work_sync(&cpts->overflow_work);
> -	}
> +	if (WARN_ON(!cpts->clock))
> +		return;
> +
> +	cancel_delayed_work_sync(&cpts->overflow_work);
> +
> +	ptp_clock_unregister(cpts->clock);
> +	cpts->clock = NULL;
>  
>  	cpts_write32(cpts, 0, int_enable);
>  	cpts_write32(cpts, 0, control);
>  
> -	if (cpts->refclk)
> -		cpts_clk_release(cpts);
> +	clk_disable(cpts->refclk);
>  }
>  EXPORT_SYMBOL_GPL(cpts_unregister);
>  
> +struct cpts *cpts_create(struct device *dev, void __iomem *regs,
> +			 u32 mult, u32 shift)
> +{
> +	struct cpts *cpts;
> +
> +	if (!regs || !dev)
> +		return ERR_PTR(-EINVAL);

There is no need for this test, as the caller will always pass valid
pointers.  (This isn't a user space library!)

Thanks,
Richard