linux-kernel - Re: [PATCH 4/4] counter: 104-quad-8: Utilize helper functions to handle PR, FLAG and PSC

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Message-ID: <ZBh9cUwvV+hi5We8@smile.fi.intel.com>
Date:   Mon, 20 Mar 2023 17:36:17 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     William Breathitt Gray <william.gray@...aro.org>
Cc:     linux-iio@...r.kernel.org, Johannes Berg <johannes.berg@...el.com>,
        Jonathan Cameron <jic23@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/4] counter: 104-quad-8: Utilize helper functions to
 handle PR, FLAG and PSC

On Mon, Mar 20, 2023 at 11:31:07AM -0400, William Breathitt Gray wrote:
> On Mon, Mar 20, 2023 at 02:28:31PM +0200, Andy Shevchenko wrote:
> > On Sat, Mar 18, 2023 at 10:59:51AM -0400, William Breathitt Gray wrote:
> > > The Preset Register (PR), Flag Register (FLAG), and Filter Clock
> > > Prescaler (PSC) have common usage patterns. Wrap up such usage into
> > > dedicated functions to improve code clarity.

...

> > > +static void quad8_preset_register_set(struct quad8 *const priv, const size_t id,
> > > +				      const unsigned long preset)
> > > +{
> > > +	struct channel_reg __iomem *const chan = priv->reg->channel + id;
> > > +	int i;
> > > +
> > > +	/* Reset Byte Pointer */
> > > +	iowrite8(SELECT_RLD | RESET_BP, &chan->control);
> > > +
> > > +	/* Set Preset Register */
> > > +	for (i = 0; i < 3; i++)
> > > +		iowrite8(preset >> (8 * i), &chan->data);
> > > +}
> > 
> > May we add generic __iowrite8_copy() / __ioread8_copy() instead?
> > 
> > It seems that even current __ioread32_copy() and __iowrite32_copy() has to
> > be amended to support IO.

> Sure, I would use __iowrite8_copy() / __ioread8_copy() for these
> situations if it were available.

If needed, you may always introduce ones.

> Is something equivalent available for the regmap API? I'm planning to
> migrate this driver to the regmap API soon after this patch series is
> merged, so the *_copy() calls would need to migrated as well.

Yes. It's regmap bulk operations.

-- 
With Best Regards,
Andy Shevchenko