Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 16 Jun 2023 17:37:37 +0300
From:   Andy Shevchenko <andriy.shevchenko@intel.com>
To:     Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc:     linux-media@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
        Luca Ceresoli <luca.ceresoli@bootlin.com>,
        Matti Vaittinen <Matti.Vaittinen@fi.rohmeurope.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Wolfram Sang <wsa@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Peter Rosin <peda@axentia.se>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Michael Tretter <m.tretter@pengutronix.de>,
        Hans Verkuil <hverkuil@xs4all.nl>,
        Mike Pagano <mpagano@gentoo.org>,
        Krzysztof =?utf-8?Q?Ha=C5=82asa?= <khalasa@piap.pl>,
        Marek Vasut <marex@denx.de>,
        Satish Nagireddy <satish.nagireddy@getcruise.com>
Subject: Re: [PATCH v14 17/18] media: i2c: ds90ub953: Restructure clkout
 management
Message-ID: <ZIxzsUbuUz3ysA31@smile.fi.intel.com>
References: <20230616135922.442979-1-tomi.valkeinen@ideasonboard.com>
 <20230616135922.442979-18-tomi.valkeinen@ideasonboard.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230616135922.442979-18-tomi.valkeinen@ideasonboard.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Precedence: bulk

On Fri, Jun 16, 2023 at 04:59:21PM +0300, Tomi Valkeinen wrote:
> Separate clkout calculations and register writes into two functions:
> ub953_calc_clkout_params and ub953_write_clkout_regs, and add a struct
> ub953_clkout_data that is used to store the clkout parameters.

...

> +struct ub953_clkout_data {
> +	u32 hs_div;
> +	u32 m;
> +	u32 n;

Please, use struxt u32_fract instead of m/n.

> +	unsigned long rate;
> +};

...

> +static void ub953_calc_clkout_params(struct ub953_data *priv,
> +				     unsigned long target_rate,
> +				     struct ub953_clkout_data *clkout_data)
> +{
> +	struct device *dev = &priv->client->dev;
> +	unsigned long clkout_rate;
> +	u64 fc_rate;
> +
> +	fc_rate = ub953_get_fc_rate(priv);
> +
> +	if (priv->hw_data->is_ub971) {
> +		u8 m, n;

Ditto. struct u8_fract; (But probably needs to be added into math.h.
I'll Ack/Rb such a patch when one appears.

> +		clkout_rate = ub953_calc_clkout_ub971(priv, target_rate,
> +						      fc_rate, &m, &n);

Can be also parameter to that function.

> +		clkout_data->m = m;
> +		clkout_data->n = n;
> +
> +		dev_dbg(dev, "%s %llu * %u / (8 * %u) = %lu (requested %lu)",
> +			__func__, fc_rate, m, n, clkout_rate, target_rate);
> +	} else {
> +		u8 hs_div, m, n;

Yeah, and so on...

> +		clkout_rate = ub953_calc_clkout_ub953(priv, target_rate,
> +						      fc_rate, &hs_div, &m, &n);
> +
> +		clkout_data->hs_div = hs_div;
> +		clkout_data->m = m;
> +		clkout_data->n = n;
> +
> +		dev_dbg(dev, "%s %llu / %u * %u / %u = %lu (requested %lu)",
> +			__func__, fc_rate, hs_div, m, n, clkout_rate,
> +			target_rate);
> +	}
> +
> +	clkout_data->rate = clkout_rate;
> +}

-- 
With Best Regards,
Andy Shevchenko