Commit e0daf1a6 authored by Michael Walle's avatar Michael Walle Committed by Guenter Roeck
Browse files

hwmon: (bt1-pvt) use generic polynomial functions 



The polynomial calculation function was moved into lib/ to be able to
reuse it. Move over to this one.

Signed-off-by: default avatarMichael Walle <michael@walle.cc>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220401214032.3738095-3-michael@walle.cc


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent cd705ea8

drivers/hwmon/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -418,6 +418,7 @@ config SENSORS_ATXP1 
config SENSORS_BT1_PVT

	tristate "Baikal-T1 Process, Voltage, Temperature sensor driver"

	depends on MIPS_BAIKAL_T1 || COMPILE_TEST

	select POLYNOMIAL

	help

	  If you say yes here you get support for Baikal-T1 PVT sensor

	  embedded into the SoC.

drivers/hwmon/bt1-pvt.c

+13 −37
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/mutex.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/polynomial.h>

#include <linux/seqlock.h>

#include <linux/sysfs.h>

#include <linux/types.h>
@@ -65,7 +66,7 @@ static const struct pvt_sensor_info pvt_info[] = { 
 *     48380,

 * where T = [-48380, 147438] mC and N = [0, 1023].

 */

static const struct pvt_poly __maybe_unused poly_temp_to_N = {

static const struct polynomial __maybe_unused poly_temp_to_N = {

	.total_divider = 10000,

	.terms = {

		{4, 18322, 10000, 10000},
@@ -76,7 +77,7 @@ static const struct pvt_poly __maybe_unused poly_temp_to_N = { 
	}

};



static const struct pvt_poly poly_N_to_temp = {

static const struct polynomial poly_N_to_temp = {

	.total_divider = 1,

	.terms = {

		{4, -16743, 1000, 1},
@@ -97,7 +98,7 @@ static const struct pvt_poly poly_N_to_temp = { 
 * N = (18658e-3*V - 11572) / 10,

 * V = N * 10^5 / 18658 + 11572 * 10^4 / 18658.

 */

static const struct pvt_poly __maybe_unused poly_volt_to_N = {

static const struct polynomial __maybe_unused poly_volt_to_N = {

	.total_divider = 10,

	.terms = {

		{1, 18658, 1000, 1},
@@ -105,7 +106,7 @@ static const struct pvt_poly __maybe_unused poly_volt_to_N = { 
	}

};



static const struct pvt_poly poly_N_to_volt = {

static const struct polynomial poly_N_to_volt = {

	.total_divider = 10,

	.terms = {

		{1, 100000, 18658, 1},
@@ -113,31 +114,6 @@ static const struct pvt_poly poly_N_to_volt = { 
	}

};



/*

 * Here is the polynomial calculation function, which performs the

 * redistributed terms calculations. It's pretty straightforward. We walk

 * over each degree term up to the free one, and perform the redistributed

 * multiplication of the term coefficient, its divider (as for the rationale

 * fraction representation), data power and the rational fraction divider

 * leftover. Then all of this is collected in a total sum variable, which

 * value is normalized by the total divider before being returned.

 */

static long pvt_calc_poly(const struct pvt_poly *poly, long data)

{

	const struct pvt_poly_term *term = poly->terms;

	long tmp, ret = 0;

	int deg;



	do {

		tmp = term->coef;

		for (deg = 0; deg < term->deg; ++deg)

			tmp = mult_frac(tmp, data, term->divider);

		ret += tmp / term->divider_leftover;

	} while ((term++)->deg);



	return ret / poly->total_divider;

}



static inline u32 pvt_update(void __iomem *reg, u32 mask, u32 data)

{

	u32 old;
@@ -324,9 +300,9 @@ static int pvt_read_data(struct pvt_hwmon *pvt, enum pvt_sensor_type type, 
	} while (read_seqretry(&cache->data_seqlock, seq));



	if (type == PVT_TEMP)

		*val = pvt_calc_poly(&poly_N_to_temp, data);

		*val = polynomial_calc(&poly_N_to_temp, data);

	else

		*val = pvt_calc_poly(&poly_N_to_volt, data);

		*val = polynomial_calc(&poly_N_to_volt, data);



	return 0;

}
@@ -345,9 +321,9 @@ static int pvt_read_limit(struct pvt_hwmon *pvt, enum pvt_sensor_type type, 
		data = FIELD_GET(PVT_THRES_HI_MASK, data);



	if (type == PVT_TEMP)

		*val = pvt_calc_poly(&poly_N_to_temp, data);

		*val = polynomial_calc(&poly_N_to_temp, data);

	else

		*val = pvt_calc_poly(&poly_N_to_volt, data);

		*val = polynomial_calc(&poly_N_to_volt, data);



	return 0;

}
@@ -360,10 +336,10 @@ static int pvt_write_limit(struct pvt_hwmon *pvt, enum pvt_sensor_type type, 


	if (type == PVT_TEMP) {

		val = clamp(val, PVT_TEMP_MIN, PVT_TEMP_MAX);

		data = pvt_calc_poly(&poly_temp_to_N, val);

		data = polynomial_calc(&poly_temp_to_N, val);

	} else {

		val = clamp(val, PVT_VOLT_MIN, PVT_VOLT_MAX);

		data = pvt_calc_poly(&poly_volt_to_N, val);

		data = polynomial_calc(&poly_volt_to_N, val);

	}



	/* Serialize limit update, since a part of the register is changed. */
@@ -522,9 +498,9 @@ static int pvt_read_data(struct pvt_hwmon *pvt, enum pvt_sensor_type type, 
		return -ETIMEDOUT;



	if (type == PVT_TEMP)

		*val = pvt_calc_poly(&poly_N_to_temp, data);

		*val = polynomial_calc(&poly_N_to_temp, data);

	else

		*val = pvt_calc_poly(&poly_N_to_volt, data);

		*val = polynomial_calc(&poly_N_to_volt, data);



	return 0;

}