From 1ad6c3b7ef132e1d8c5d606008069724625c8daf Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Tue, 5 Apr 2022 11:24:51 +0200 Subject: hwmon: introduce hwmon_sanitize_name() More and more drivers will check for bad characters in the hwmon name and all are using the same code snippet. Consolidate that code by adding a new hwmon_sanitize_name() function. Signed-off-by: Michael Walle Reviewed-by: Tom Rix Link: https://lore.kernel.org/r/20220405092452.4033674-2-michael@walle.cc Signed-off-by: Guenter Roeck --- include/linux/hwmon.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h index eba380b76d15..4efaf06fd2b8 100644 --- a/include/linux/hwmon.h +++ b/include/linux/hwmon.h @@ -461,6 +461,9 @@ void devm_hwmon_device_unregister(struct device *dev); int hwmon_notify_event(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel); +char *hwmon_sanitize_name(const char *name); +char *devm_hwmon_sanitize_name(struct device *dev, const char *name); + /** * hwmon_is_bad_char - Is the char invalid in a hwmon name * @ch: the char to be considered -- cgit v1.2.3 From cd705ea857fdd859a9df09e8adda4cb4c906e8a2 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Fri, 1 Apr 2022 23:40:29 +0200 Subject: lib: add generic polynomial calculation Some temperature and voltage sensors use a polynomial to convert between raw data points and actual temperature or voltage. The polynomial is usually the result of a curve fitting of the diode characteristic. The BT1 PVT hwmon driver already uses such a polynonmial calculation which is rather generic. Move it to lib/ so other drivers can reuse it. Signed-off-by: Michael Walle Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20220401214032.3738095-2-michael@walle.cc Signed-off-by: Guenter Roeck --- include/linux/polynomial.h | 35 +++++++++++++++ lib/Kconfig | 3 ++ lib/Makefile | 2 + lib/polynomial.c | 108 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 148 insertions(+) create mode 100644 include/linux/polynomial.h create mode 100644 lib/polynomial.c (limited to 'include') diff --git a/include/linux/polynomial.h b/include/linux/polynomial.h new file mode 100644 index 000000000000..9e074a0bb6fa --- /dev/null +++ b/include/linux/polynomial.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC + */ + +#ifndef _POLYNOMIAL_H +#define _POLYNOMIAL_H + +/* + * struct polynomial_term - one term descriptor of a polynomial + * @deg: degree of the term. + * @coef: multiplication factor of the term. + * @divider: distributed divider per each degree. + * @divider_leftover: divider leftover, which couldn't be redistributed. + */ +struct polynomial_term { + unsigned int deg; + long coef; + long divider; + long divider_leftover; +}; + +/* + * struct polynomial - a polynomial descriptor + * @total_divider: total data divider. + * @terms: polynomial terms, last term must have degree of 0 + */ +struct polynomial { + long total_divider; + struct polynomial_term terms[]; +}; + +long polynomial_calc(const struct polynomial *poly, long data); + +#endif diff --git a/lib/Kconfig b/lib/Kconfig index 087e06b4cdfd..6a843639814f 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -737,3 +737,6 @@ config PLDMFW config ASN1_ENCODER tristate + +config POLYNOMIAL + tristate diff --git a/lib/Makefile b/lib/Makefile index 6b9ffc1bd1ee..89fcae891361 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -263,6 +263,8 @@ obj-$(CONFIG_MEMREGION) += memregion.o obj-$(CONFIG_STMP_DEVICE) += stmp_device.o obj-$(CONFIG_IRQ_POLL) += irq_poll.o +obj-$(CONFIG_POLYNOMIAL) += polynomial.o + # stackdepot.c should not be instrumented or call instrumented functions. # Prevent the compiler from calling builtins like memcmp() or bcmp() from this # file. diff --git a/lib/polynomial.c b/lib/polynomial.c new file mode 100644 index 000000000000..66d383445fec --- /dev/null +++ b/lib/polynomial.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Generic polynomial calculation using integer coefficients. + * + * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC + * + * Authors: + * Maxim Kaurkin + * Serge Semin + * + */ + +#include +#include +#include + +/* + * Originally this was part of drivers/hwmon/bt1-pvt.c. + * There the following conversion is used and should serve as an example here: + * + * The original translation formulae of the temperature (in degrees of Celsius) + * to PVT data and vice-versa are following: + * + * N = 1.8322e-8*(T^4) + 2.343e-5*(T^3) + 8.7018e-3*(T^2) + 3.9269*(T^1) + + * 1.7204e2 + * T = -1.6743e-11*(N^4) + 8.1542e-8*(N^3) + -1.8201e-4*(N^2) + + * 3.1020e-1*(N^1) - 4.838e1 + * + * where T = [-48.380, 147.438]C and N = [0, 1023]. + * + * They must be accordingly altered to be suitable for the integer arithmetics. + * The technique is called 'factor redistribution', which just makes sure the + * multiplications and divisions are made so to have a result of the operations + * within the integer numbers limit. In addition we need to translate the + * formulae to accept millidegrees of Celsius. Here what they look like after + * the alterations: + * + * N = (18322e-20*(T^4) + 2343e-13*(T^3) + 87018e-9*(T^2) + 39269e-3*T + + * 17204e2) / 1e4 + * T = -16743e-12*(D^4) + 81542e-9*(D^3) - 182010e-6*(D^2) + 310200e-3*D - + * 48380 + * where T = [-48380, 147438] mC and N = [0, 1023]. + * + * static const struct polynomial poly_temp_to_N = { + * .total_divider = 10000, + * .terms = { + * {4, 18322, 10000, 10000}, + * {3, 2343, 10000, 10}, + * {2, 87018, 10000, 10}, + * {1, 39269, 1000, 1}, + * {0, 1720400, 1, 1} + * } + * }; + * + * static const struct polynomial poly_N_to_temp = { + * .total_divider = 1, + * .terms = { + * {4, -16743, 1000, 1}, + * {3, 81542, 1000, 1}, + * {2, -182010, 1000, 1}, + * {1, 310200, 1000, 1}, + * {0, -48380, 1, 1} + * } + * }; + */ + +/** + * polynomial_calc - calculate a polynomial using integer arithmetic + * + * @poly: pointer to the descriptor of the polynomial + * @data: input value of the polynimal + * + * Calculate the result of a polynomial using only integer arithmetic. For + * this to work without too much loss of precision the coefficients has to + * be altered. This is called factor redistribution. + * + * Returns the result of the polynomial calculation. + */ +long polynomial_calc(const struct polynomial *poly, long data) +{ + const struct polynomial_term *term = poly->terms; + long total_divider = poly->total_divider ?: 1; + long tmp, ret = 0; + int deg; + + /* + * 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. + */ + 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 / total_divider; +} +EXPORT_SYMBOL_GPL(polynomial_calc); + +MODULE_DESCRIPTION("Generic polynomial calculations"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3 From e5d21072054fbadf41cd56062a3a14e447e8c22b Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Wed, 11 May 2022 06:29:59 -0700 Subject: hwmon: Introduce hwmon_device_register_for_thermal The thermal subsystem registers a hwmon driver without providing chip or sysfs group information. This is for legacy reasons and would be difficult to change. At the same time, we want to enforce that chip information is provided when registering a hwmon device using hwmon_device_register_with_info(). To enable this, introduce a special API for use only by the thermal subsystem. Acked-by: Rafael J . Wysocki Signed-off-by: Guenter Roeck --- drivers/hwmon/hwmon.c | 25 +++++++++++++++++++++++++ include/linux/hwmon.h | 3 +++ 2 files changed, 28 insertions(+) (limited to 'include') diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c index 5915ccfdb7d9..13053a4edc9e 100644 --- a/drivers/hwmon/hwmon.c +++ b/drivers/hwmon/hwmon.c @@ -916,6 +916,31 @@ hwmon_device_register_with_info(struct device *dev, const char *name, } EXPORT_SYMBOL_GPL(hwmon_device_register_with_info); +/** + * hwmon_device_register_for_thermal - register hwmon device for thermal subsystem + * @dev: the parent device + * @name: hwmon name attribute + * @drvdata: driver data to attach to created device + * + * The use of this function is restricted. It is provided for legacy reasons + * and must only be called from the thermal subsystem. + * + * hwmon_device_unregister() must be called when the device is no + * longer needed. + * + * Returns the pointer to the new device. + */ +struct device * +hwmon_device_register_for_thermal(struct device *dev, const char *name, + void *drvdata) +{ + if (!name || !dev) + return ERR_PTR(-EINVAL); + + return __hwmon_device_register(dev, name, drvdata, NULL, NULL); +} +EXPORT_SYMBOL_NS_GPL(hwmon_device_register_for_thermal, HWMON_THERMAL); + /** * hwmon_device_register - register w/ hwmon * @dev: the device to register diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h index 4efaf06fd2b8..14325f93c6b2 100644 --- a/include/linux/hwmon.h +++ b/include/linux/hwmon.h @@ -450,6 +450,9 @@ hwmon_device_register_with_info(struct device *dev, const struct hwmon_chip_info *info, const struct attribute_group **extra_groups); struct device * +hwmon_device_register_for_thermal(struct device *dev, const char *name, + void *drvdata); +struct device * devm_hwmon_device_register_with_info(struct device *dev, const char *name, void *drvdata, const struct hwmon_chip_info *info, -- cgit v1.2.3