Hi Miquèl,
On Fri, Dec 22, 2017 at 10:32:21AM +0100, Miquel Raynal wrote:
> From: Baruch Siach <baruch@xxxxxxxxxx>
>
> 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 <baruch@xxxxxxxxxx>
> [<miquel.raynal@xxxxxxxxxxxxxxxxxx>: 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 <miquel.raynal@xxxxxxxxxxxxxxxxxx>
> Reviewed-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> Tested-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> ---
[..]
> 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 <linux/math64.h>
if (priv->data->inverted)
*temp = div_s64((m * sample) - b, div);
else
*temp = div_s64(b - (m * sample), div);
baruch
> +
> return 0;
> }
--
http://baruch.siach.name/blog/ ~. .~ Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
- baruch@xxxxxxxxxx - tel: +972.52.368.4656, http://www.tkos.co.il -
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