Merge tag 'regulator-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator updates from Mark Brown:
 "The big change in this release is that Matti Vaittinen has factored
  out the linear ranges support into a separate library in lib/ since it
  is also useful for at least the power subsystem (and most likely
  others too), it helps subsystems which need to map register values
  into more useful real world values do so with minimal per-driver code.

   - Factoring out of the linear ranges support into a library in lib/
     from Matti Vaittinen.

   - Trace points for bypass mode.

   - Use the consumer name in debugfs to make it easier to understand.

   - New drivers for Maxim MAX77826 and MAX8998"

* tag 'regulator-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (23 commits)
  regulator: max8998: max8998_set_current_limit() can be static
  dt-bindings: regulator: Convert anatop regulator to json-schema
  regulator: core: Add regulator bypass trace points
  regulator: extract voltage balancing code to the separate function
  regulator/mfd: max8998: Document charger regulator
  regulator: max8998: Add charger regulator
  MAINTAINERS: Add maintainer entry for linear ranges helper
  regulator: bd718x7: remove voltage change restriction from BD71847 LDOs
  lib: linear_ranges: Add missing MODULE_LICENSE()
  regulator: use linear_ranges helper
  power: supply: bd70528: rename linear_range to avoid collision
  lib/test_linear_ranges: add a test for the 'linear_ranges'
  lib: add linear ranges helpers
  regulator: db8500-prcmu: Use true,false for bool variable
  regulator: bd718x7: remove voltage change restriction from BD71847
  regulator: max77826: Remove erroneous additionalProperties
  regulator: qcom-rpmh: Fix typos in pm8150 and pm8150l
  regulator: Document bindings for max77826
  regulator: max77826: Add max77826 regulator driver
  regulator: tps80031: remove redundant assignment to variables ret and val
  ...

5 files changed, 490 insertions, 0 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index 5d53f9609c25..8ec05335426c 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -19,6 +19,9 @@ config RAID6_PQ_BENCHMARK
 	  Benchmark all available RAID6 PQ functions on init and choose the
 	  fastest one.
 
+config LINEAR_RANGES
+	tristate
+
 config PACKING
 	bool "Generic bitfield packing and unpacking"
 	default n
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 21d9c5f6e7ec..f3322a620674 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2092,6 +2092,18 @@ config LIST_KUNIT_TEST
 
 	  If unsure, say N.
 
+config LINEAR_RANGES_TEST
+	tristate "KUnit test for linear_ranges"
+	depends on KUNIT
+	select LINEAR_RANGES
+	help
+	  This builds the linear_ranges unit test, which runs on boot.
+	  Tests the linear_ranges logic correctness.
+	  For more information on KUnit and unit tests in general please refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+	  If unsure, say N.
+
 config TEST_UDELAY
 	tristate "udelay test driver"
 	help
diff --git a/lib/Makefile b/lib/Makefile
index 685aee60de1d..cd548bfa8df9 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -125,6 +125,7 @@ obj-$(CONFIG_DEBUG_LIST) += list_debug.o
 obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o
 
 obj-$(CONFIG_BITREVERSE) += bitrev.o
+obj-$(CONFIG_LINEAR_RANGES) += linear_ranges.o
 obj-$(CONFIG_PACKING)	+= packing.o
 obj-$(CONFIG_CRC_CCITT)	+= crc-ccitt.o
 obj-$(CONFIG_CRC16)	+= crc16.o
@@ -309,3 +310,4 @@ obj-$(CONFIG_OBJAGG) += objagg.o
 
 # KUnit tests
 obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
+obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
diff --git a/lib/linear_ranges.c b/lib/linear_ranges.c
new file mode 100644
index 000000000000..9495ef3572b7
--- /dev/null
+++ b/lib/linear_ranges.c
@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * helpers to map values in a linear range to range index
+ *
+ * Original idea borrowed from regulator framework
+ *
+ * It might be useful if we could support also inversely proportional ranges?
+ * Copyright 2020 ROHM Semiconductors
+ */
+
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/linear_range.h>
+#include <linux/module.h>
+
+/**
+ * linear_range_values_in_range - return the amount of values in a range
+ * @r:		pointer to linear range where values are counted
+ *
+ * Compute the amount of values in range pointed by @r. Note, values can
+ * be all equal - range with selectors 0,...,2 with step 0 still contains
+ * 3 values even though they are all equal.
+ *
+ * Return: the amount of values in range pointed by @r
+ */
+unsigned int linear_range_values_in_range(const struct linear_range *r)
+{
+	if (!r)
+		return 0;
+	return r->max_sel - r->min_sel + 1;
+}
+EXPORT_SYMBOL_GPL(linear_range_values_in_range);
+
+/**
+ * linear_range_values_in_range_array - return the amount of values in ranges
+ * @r:		pointer to array of linear ranges where values are counted
+ * @ranges:	amount of ranges we include in computation.
+ *
+ * Compute the amount of values in ranges pointed by @r. Note, values can
+ * be all equal - range with selectors 0,...,2 with step 0 still contains
+ * 3 values even though they are all equal.
+ *
+ * Return: the amount of values in first @ranges ranges pointed by @r
+ */
+unsigned int linear_range_values_in_range_array(const struct linear_range *r,
+						int ranges)
+{
+	int i, values_in_range = 0;
+
+	for (i = 0; i < ranges; i++) {
+		int values;
+
+		values = linear_range_values_in_range(&r[i]);
+		if (!values)
+			return values;
+
+		values_in_range += values;
+	}
+	return values_in_range;
+}
+EXPORT_SYMBOL_GPL(linear_range_values_in_range_array);
+
+/**
+ * linear_range_get_max_value - return the largest value in a range
+ * @r:		pointer to linear range where value is looked from
+ *
+ * Return: the largest value in the given range
+ */
+unsigned int linear_range_get_max_value(const struct linear_range *r)
+{
+	return r->min + (r->max_sel - r->min_sel) * r->step;
+}
+EXPORT_SYMBOL_GPL(linear_range_get_max_value);
+
+/**
+ * linear_range_get_value - fetch a value from given range
+ * @r:		pointer to linear range where value is looked from
+ * @selector:	selector for which the value is searched
+ * @val:	address where found value is updated
+ *
+ * Search given ranges for value which matches given selector.
+ *
+ * Return: 0 on success, -EINVAL given selector is not found from any of the
+ * ranges.
+ */
+int linear_range_get_value(const struct linear_range *r, unsigned int selector,
+			   unsigned int *val)
+{
+	if (r->min_sel > selector || r->max_sel < selector)
+		return -EINVAL;
+
+	*val = r->min + (selector - r->min_sel) * r->step;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(linear_range_get_value);
+
+/**
+ * linear_range_get_value_array - fetch a value from array of ranges
+ * @r:		pointer to array of linear ranges where value is looked from
+ * @ranges:	amount of ranges in an array
+ * @selector:	selector for which the value is searched
+ * @val:	address where found value is updated
+ *
+ * Search through an array of ranges for value which matches given selector.
+ *
+ * Return: 0 on success, -EINVAL given selector is not found from any of the
+ * ranges.
+ */
+int linear_range_get_value_array(const struct linear_range *r, int ranges,
+				 unsigned int selector, unsigned int *val)
+{
+	int i;
+
+	for (i = 0; i < ranges; i++)
+		if (r[i].min_sel <= selector && r[i].max_sel >= selector)
+			return linear_range_get_value(&r[i], selector, val);
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(linear_range_get_value_array);
+
+/**
+ * linear_range_get_selector_low - return linear range selector for value
+ * @r:		pointer to linear range where selector is looked from
+ * @val:	value for which the selector is searched
+ * @selector:	address where found selector value is updated
+ * @found:	flag to indicate that given value was in the range
+ *
+ * Return selector which which range value is closest match for given
+ * input value. Value is matching if it is equal or smaller than given
+ * value. If given value is in the range, then @found is set true.
+ *
+ * Return: 0 on success, -EINVAL if range is invalid or does not contain
+ * value smaller or equal to given value
+ */
+int linear_range_get_selector_low(const struct linear_range *r,
+				  unsigned int val, unsigned int *selector,
+				  bool *found)
+{
+	*found = false;
+
+	if (r->min > val)
+		return -EINVAL;
+
+	if (linear_range_get_max_value(r) < val) {
+		*selector = r->max_sel;
+		return 0;
+	}
+
+	*found = true;
+
+	if (r->step == 0)
+		*selector = r->min_sel;
+	else
+		*selector = (val - r->min) / r->step + r->min_sel;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(linear_range_get_selector_low);
+
+/**
+ * linear_range_get_selector_low_array - return linear range selector for value
+ * @r:		pointer to array of linear ranges where selector is looked from
+ * @ranges:	amount of ranges to scan from array
+ * @val:	value for which the selector is searched
+ * @selector:	address where found selector value is updated
+ * @found:	flag to indicate that given value was in the range
+ *
+ * Scan array of ranges for selector which which range value matches given
+ * input value. Value is matching if it is equal or smaller than given
+ * value. If given value is found to be in a range scanning is stopped and
+ * @found is set true. If a range with values smaller than given value is found
+ * but the range max is being smaller than given value, then the ranges
+ * biggest selector is updated to @selector but scanning ranges is continued
+ * and @found is set to false.
+ *
+ * Return: 0 on success, -EINVAL if range array is invalid or does not contain
+ * range with a value smaller or equal to given value
+ */
+int linear_range_get_selector_low_array(const struct linear_range *r,
+					int ranges, unsigned int val,
+					unsigned int *selector, bool *found)
+{
+	int i;
+	int ret = -EINVAL;
+
+	for (i = 0; i < ranges; i++) {
+		int tmpret;
+
+		tmpret = linear_range_get_selector_low(&r[i], val, selector,
+						       found);
+		if (!tmpret)
+			ret = 0;
+
+		if (*found)
+			break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(linear_range_get_selector_low_array);
+
+/**
+ * linear_range_get_selector_high - return linear range selector for value
+ * @r:		pointer to linear range where selector is looked from
+ * @val:	value for which the selector is searched
+ * @selector:	address where found selector value is updated
+ * @found:	flag to indicate that given value was in the range
+ *
+ * Return selector which which range value is closest match for given
+ * input value. Value is matching if it is equal or higher than given
+ * value. If given value is in the range, then @found is set true.
+ *
+ * Return: 0 on success, -EINVAL if range is invalid or does not contain
+ * value greater or equal to given value
+ */
+int linear_range_get_selector_high(const struct linear_range *r,
+				   unsigned int val, unsigned int *selector,
+				   bool *found)
+{
+	*found = false;
+
+	if (linear_range_get_max_value(r) < val)
+		return -EINVAL;
+
+	if (r->min > val) {
+		*selector = r->min_sel;
+		return 0;
+	}
+
+	*found = true;
+
+	if (r->step == 0)
+		*selector = r->max_sel;
+	else
+		*selector = DIV_ROUND_UP(val - r->min, r->step) + r->min_sel;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(linear_range_get_selector_high);
+
+MODULE_DESCRIPTION("linear-ranges helper");
+MODULE_LICENSE("GPL");
diff --git a/lib/test_linear_ranges.c b/lib/test_linear_ranges.c
new file mode 100644
index 000000000000..676e0b8abcdd
--- /dev/null
+++ b/lib/test_linear_ranges.c
@@ -0,0 +1,228 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for the linear_ranges helper.
+ *
+ * Copyright (C) 2020, ROHM Semiconductors.
+ * Author: Matti Vaittinen <matti.vaittien@fi.rohmeurope.com>
+ */
+#include <kunit/test.h>
+
+#include <linux/linear_range.h>
+
+/* First things first. I deeply dislike unit-tests. I have seen all the hell
+ * breaking loose when people who think the unit tests are "the silver bullet"
+ * to kill bugs get to decide how a company should implement testing strategy...
+ *
+ * Believe me, it may get _really_ ridiculous. It is tempting to think that
+ * walking through all the possible execution branches will nail down 100% of
+ * bugs. This may lead to ideas about demands to get certain % of "test
+ * coverage" - measured as line coverage. And that is one of the worst things
+ * you can do.
+ *
+ * Ask people to provide line coverage and they do. I've seen clever tools
+ * which generate test cases to test the existing functions - and by default
+ * these tools expect code to be correct and just generate checks which are
+ * passing when ran against current code-base. Run this generator and you'll get
+ * tests that do not test code is correct but just verify nothing changes.
+ * Problem is that testing working code is pointless. And if it is not
+ * working, your test must not assume it is working. You won't catch any bugs
+ * by such tests. What you can do is to generate a huge amount of tests.
+ * Especially if you were are asked to proivde 100% line-coverage x_x. So what
+ * does these tests - which are not finding any bugs now - do?
+ *
+ * They add inertia to every future development. I think it was Terry Pratchet
+ * who wrote someone having same impact as thick syrup has to chronometre.
+ * Excessive amount of unit-tests have this effect to development. If you do
+ * actually find _any_ bug from code in such environment and try fixing it...
+ * ...chances are you also need to fix the test cases. In sunny day you fix one
+ * test. But I've done refactoring which resulted 500+ broken tests (which had
+ * really zero value other than proving to managers that we do do "quality")...
+ *
+ * After this being said - there are situations where UTs can be handy. If you
+ * have algorithms which take some input and should produce output - then you
+ * can implement few, carefully selected simple UT-cases which test this. I've
+ * previously used this for example for netlink and device-tree data parsing
+ * functions. Feed some data examples to functions and verify the output is as
+ * expected. I am not covering all the cases but I will see the logic should be
+ * working.
+ *
+ * Here we also do some minor testing. I don't want to go through all branches
+ * or test more or less obvious things - but I want to see the main logic is
+ * working. And I definitely don't want to add 500+ test cases that break when
+ * some simple fix is done x_x. So - let's only add few, well selected tests
+ * which ensure as much logic is good as possible.
+ */
+
+/*
+ * Test Range 1:
+ * selectors:	2	3	4	5	6
+ * values (5):	10	20	30	40	50
+ *
+ * Test Range 2:
+ * selectors:	7	8	9	10
+ * values (4):	100	150	200	250
+ */
+
+#define RANGE1_MIN 10
+#define RANGE1_MIN_SEL 2
+#define RANGE1_STEP 10
+
+/* 2, 3, 4, 5, 6 */
+static const unsigned int range1_sels[] = { RANGE1_MIN_SEL, RANGE1_MIN_SEL + 1,
+					    RANGE1_MIN_SEL + 2,
+					    RANGE1_MIN_SEL + 3,
+					    RANGE1_MIN_SEL + 4 };
+/* 10, 20, 30, 40, 50 */
+static const unsigned int range1_vals[] = { RANGE1_MIN, RANGE1_MIN +
+					    RANGE1_STEP,
+					    RANGE1_MIN + RANGE1_STEP * 2,
+					    RANGE1_MIN + RANGE1_STEP * 3,
+					    RANGE1_MIN + RANGE1_STEP * 4 };
+
+#define RANGE2_MIN 100
+#define RANGE2_MIN_SEL 7
+#define RANGE2_STEP 50
+
+/*  7, 8, 9, 10 */
+static const unsigned int range2_sels[] = { RANGE2_MIN_SEL, RANGE2_MIN_SEL + 1,
+					    RANGE2_MIN_SEL + 2,
+					    RANGE2_MIN_SEL + 3 };
+/* 100, 150, 200, 250 */
+static const unsigned int range2_vals[] = { RANGE2_MIN, RANGE2_MIN +
+					    RANGE2_STEP,
+					    RANGE2_MIN + RANGE2_STEP * 2,
+					    RANGE2_MIN + RANGE2_STEP * 3 };
+
+#define RANGE1_NUM_VALS (ARRAY_SIZE(range1_vals))
+#define RANGE2_NUM_VALS (ARRAY_SIZE(range2_vals))
+#define RANGE_NUM_VALS (RANGE1_NUM_VALS + RANGE2_NUM_VALS)
+
+#define RANGE1_MAX_SEL (RANGE1_MIN_SEL + RANGE1_NUM_VALS - 1)
+#define RANGE1_MAX_VAL (range1_vals[RANGE1_NUM_VALS - 1])
+
+#define RANGE2_MAX_SEL (RANGE2_MIN_SEL + RANGE2_NUM_VALS - 1)
+#define RANGE2_MAX_VAL (range2_vals[RANGE2_NUM_VALS - 1])
+
+#define SMALLEST_SEL RANGE1_MIN_SEL
+#define SMALLEST_VAL RANGE1_MIN
+
+static struct linear_range testr[] = {
+	{
+		.min = RANGE1_MIN,
+		.min_sel = RANGE1_MIN_SEL,
+		.max_sel = RANGE1_MAX_SEL,
+		.step = RANGE1_STEP,
+	}, {
+		.min = RANGE2_MIN,
+		.min_sel = RANGE2_MIN_SEL,
+		.max_sel = RANGE2_MAX_SEL,
+		.step = RANGE2_STEP
+	},
+};
+
+static void range_test_get_value(struct kunit *test)
+{
+	int ret, i;
+	unsigned int sel, val;
+
+	for (i = 0; i < RANGE1_NUM_VALS; i++) {
+		sel = range1_sels[i];
+		ret = linear_range_get_value_array(&testr[0], 2, sel, &val);
+		KUNIT_EXPECT_EQ(test, 0, ret);
+		KUNIT_EXPECT_EQ(test, val, range1_vals[i]);
+	}
+	for (i = 0; i < RANGE2_NUM_VALS; i++) {
+		sel = range2_sels[i];
+		ret = linear_range_get_value_array(&testr[0], 2, sel, &val);
+		KUNIT_EXPECT_EQ(test, 0, ret);
+		KUNIT_EXPECT_EQ(test, val, range2_vals[i]);
+	}
+	ret = linear_range_get_value_array(&testr[0], 2, sel + 1, &val);
+	KUNIT_EXPECT_NE(test, 0, ret);
+}
+
+static void range_test_get_selector_high(struct kunit *test)
+{
+	int ret, i;
+	unsigned int sel;
+	bool found;
+
+	for (i = 0; i < RANGE1_NUM_VALS; i++) {
+		ret = linear_range_get_selector_high(&testr[0], range1_vals[i],
+						     &sel, &found);
+		KUNIT_EXPECT_EQ(test, 0, ret);
+		KUNIT_EXPECT_EQ(test, sel, range1_sels[i]);
+		KUNIT_EXPECT_TRUE(test, found);
+	}
+
+	ret = linear_range_get_selector_high(&testr[0], RANGE1_MAX_VAL + 1,
+					     &sel, &found);
+	KUNIT_EXPECT_LE(test, ret, 0);
+
+	ret = linear_range_get_selector_high(&testr[0], RANGE1_MIN - 1,
+					     &sel, &found);
+	KUNIT_EXPECT_EQ(test, 0, ret);
+	KUNIT_EXPECT_FALSE(test, found);
+	KUNIT_EXPECT_EQ(test, sel, range1_sels[0]);
+}
+
+static void range_test_get_value_amount(struct kunit *test)
+{
+	int ret;
+
+	ret = linear_range_values_in_range_array(&testr[0], 2);
+	KUNIT_EXPECT_EQ(test, (int)RANGE_NUM_VALS, ret);
+}
+
+static void range_test_get_selector_low(struct kunit *test)
+{
+	int i, ret;
+	unsigned int sel;
+	bool found;
+
+	for (i = 0; i < RANGE1_NUM_VALS; i++) {
+		ret = linear_range_get_selector_low_array(&testr[0], 2,
+							  range1_vals[i], &sel,
+							  &found);
+		KUNIT_EXPECT_EQ(test, 0, ret);
+		KUNIT_EXPECT_EQ(test, sel, range1_sels[i]);
+		KUNIT_EXPECT_TRUE(test, found);
+	}
+	for (i = 0; i < RANGE2_NUM_VALS; i++) {
+		ret = linear_range_get_selector_low_array(&testr[0], 2,
+							  range2_vals[i], &sel,
+							  &found);
+		KUNIT_EXPECT_EQ(test, 0, ret);
+		KUNIT_EXPECT_EQ(test, sel, range2_sels[i]);
+		KUNIT_EXPECT_TRUE(test, found);
+	}
+
+	/*
+	 * Seek value greater than range max => get_selector_*_low should
+	 * return Ok - but set found to false as value is not in range
+	 */
+	ret = linear_range_get_selector_low_array(&testr[0], 2,
+					range2_vals[RANGE2_NUM_VALS - 1] + 1,
+					&sel, &found);
+
+	KUNIT_EXPECT_EQ(test, 0, ret);
+	KUNIT_EXPECT_EQ(test, sel, range2_sels[RANGE2_NUM_VALS - 1]);
+	KUNIT_EXPECT_FALSE(test, found);
+}
+
+static struct kunit_case range_test_cases[] = {
+	KUNIT_CASE(range_test_get_value_amount),
+	KUNIT_CASE(range_test_get_selector_high),
+	KUNIT_CASE(range_test_get_selector_low),
+	KUNIT_CASE(range_test_get_value),
+	{},
+};
+
+static struct kunit_suite range_test_module = {
+	.name = "linear-ranges-test",
+	.test_cases = range_test_cases,
+};
+
+kunit_test_suites(&range_test_module);
+
+MODULE_LICENSE("GPL");