From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baruch Siach Subject: Re: [PATCH v6 06/11] thermal: armada: Add support for Armada AP806 Date: Fri, 22 Dec 2017 13:03:50 +0200 Message-ID: <20171222110350.zq2hlrctbzbkbrm7@tarshish> References: <20171222093226.23456-1-miquel.raynal@free-electrons.com> <20171222093226.23456-7-miquel.raynal@free-electrons.com> <20171222101426.yujvg2xbca3ghpyc@tarshish> <20171222114948.32c36369@xps13> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20171222114948.32c36369@xps13> Sender: linux-pm-owner@vger.kernel.org To: Miquel RAYNAL Cc: Zhang Rui , Eduardo Valentin , Rob Herring , Mark Rutland , linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Thomas Petazzoni , Gregory Clement , Antoine Tenart , Nadav Haklai , David Sniatkiwicz List-Id: devicetree@vger.kernel.org Hi Miquèl, On Fri, Dec 22, 2017 at 11:49:48AM +0100, Miquel RAYNAL wrote: > On Fri, 22 Dec 2017 12:14:26 +0200 > Baruch Siach wrote: > > On Fri, Dec 22, 2017 at 10:32:21AM +0100, Miquel Raynal wrote: > > > From: Baruch Siach > > > > > > The AP806 component is integrated in the Armada 8K and 7K lines of > > > processors. > > > > > > The thermal sensor sample field on the status register is a signed > > > value. Extend armada_get_temp() and the driver structure to handle > > > signed values. > > > > > > Signed-off-by: Baruch Siach > > > [: Changes when applying over the > > > previous patches, including the register names changes, also > > > switched the coefficients values to s64 instead of unsigned long to > > > deal with negative values and used do_div instead of the > > > traditionnal '/'] Signed-off-by: Miquel Raynal > > > Reviewed-by: Gregory CLEMENT > > > Tested-by: Gregory CLEMENT > > > --- > > > > [..] > > > > > static int armada_get_temp(struct thermal_zone_device *thermal, > > > - int *temp) > > > + int *temperature) > > > { > > > struct armada_thermal_priv *priv = thermal->devdata; > > > - unsigned long reg; > > > - unsigned long m, b, div; > > > + u32 reg, div; > > > + s64 sample, b, m; > > > + u64 tmp; > > > > > > /* Valid check */ > > > if (priv->data->is_valid && !priv->data->is_valid(priv)) { > > > @@ -178,6 +197,11 @@ static int armada_get_temp(struct > > > thermal_zone_device *thermal, > > > reg = readl_relaxed(priv->status); > > > reg = (reg >> priv->data->temp_shift) & > > > priv->data->temp_mask; > > > + if (priv->data->signed_sample) > > > + /* The most significant bit is the sign bit */ > > > + sample = sign_extend32(reg, > > > fls(priv->data->temp_mask) - 1); > > > + else > > > + sample = reg; > > > > > > /* Get formula coeficients */ > > > b = priv->data->coef_b; > > > @@ -185,9 +209,13 @@ static int armada_get_temp(struct > > > thermal_zone_device *thermal, div = priv->data->coef_div; > > > > > > if (priv->data->inverted) > > > - *temp = ((m * reg) - b) / div; > > > + tmp = (m * sample) - b; > > > else > > > - *temp = (b - (m * reg)) / div; > > > + tmp = b - (m * sample); > > > + > > > + do_div(tmp, div); > > > + *temperature = (int)tmp; > > > > Nitpick: why not (untested) > > > > #include > > > > if (priv->data->inverted) > > *temp = div_s64((m * sample) - b, div); > > else > > *temp = div_s64(b - (m * sample), div); > > Indeed I could also use div_s64, but the result must be unsigned anyway. *temp is signed, as far as I can see. Temperature can go below zero, at least in the Celsius scale. > But this does all the operations on the same line, maybe this is more > readable, I will update it and send (hopefully) the last version :) baruch -- http://baruch.siach.name/blog/ ~. .~ Tk Open Systems =}------------------------------------------------ooO--U--Ooo------------{= - baruch@tkos.co.il - tel: +972.52.368.4656, http://www.tkos.co.il -