Merge tag 'regmap-v6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "The main change here is the implementation of a mechanism for
  generating register defaults via a callback rather than with a table
  in the driver.

  This is useful for devices where there are large ranges of registers
  with the same or generated values, it allows us to have a small amount
  of code instead of a larger amount of default data"

* tag 'regmap-v6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regcache: Demote defaults readback from HW to debug print
  regmap: add KUnit coverage for reg_default_cb callback
  regmap: Add reg_default_cb callback for flat cache defaults
  regmap: Enable REGMAP when REGMAP_SLIMBUS is enabled

6 files changed, 119 insertions, 3 deletions

diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
index ffb2ef488298..06d7eb2aac14 100644
--- a/drivers/base/regmap/Kconfig
+++ b/drivers/base/regmap/Kconfig
@@ -5,7 +5,7 @@
 
 config REGMAP
 	bool
-	default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_W1 || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ || REGMAP_SOUNDWIRE || REGMAP_SOUNDWIRE_MBQ || REGMAP_SCCB || REGMAP_I3C || REGMAP_SPI_AVMM || REGMAP_MDIO || REGMAP_FSI)
+	default y if (REGMAP_I2C || REGMAP_SLIMBUS || REGMAP_SPI || REGMAP_SPMI || REGMAP_W1 || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ || REGMAP_SOUNDWIRE || REGMAP_SOUNDWIRE_MBQ || REGMAP_SCCB || REGMAP_I3C || REGMAP_SPI_AVMM || REGMAP_MDIO || REGMAP_FSI)
 	help
 	  Enable support for the Register Map (regmap) access API.
 
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 1477329410ec..5bf993165438 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -117,6 +117,9 @@ struct regmap {
 		    void *val_buf, size_t val_size);
 	int (*write)(void *context, const void *data, size_t count);
 
+	int (*reg_default_cb)(struct device *dev, unsigned int reg,
+			      unsigned int *val);
+
 	unsigned long read_flag_mask;
 	unsigned long write_flag_mask;
 
diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regcache-flat.c
index 53cc59c84e2f..c924817e19b1 100644
--- a/drivers/base/regmap/regcache-flat.c
+++ b/drivers/base/regmap/regcache-flat.c
@@ -79,6 +79,25 @@ static int regcache_flat_populate(struct regmap *map)
 		__set_bit(index, cache->valid);
 	}
 
+	if (map->reg_default_cb) {
+		dev_dbg(map->dev,
+			"Populating regcache_flat using reg_default_cb callback\n");
+
+		for (i = 0; i <= map->max_register; i += map->reg_stride) {
+			unsigned int index = regcache_flat_get_index(map, i);
+			unsigned int value;
+
+			if (test_bit(index, cache->valid))
+				continue;
+
+			if (map->reg_default_cb(map->dev, i, &value))
+				continue;
+
+			cache->data[index] = value;
+			__set_bit(index, cache->valid);
+		}
+	}
+
 	return 0;
 }
 
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 319c342bf5a0..d596526dccbb 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -73,7 +73,7 @@ static int regcache_hw_init(struct regmap *map)
 
 	if (!map->reg_defaults_raw) {
 		bool cache_bypass = map->cache_bypass;
-		dev_warn(map->dev, "No cache defaults, reading back from HW\n");
+		dev_dbg(map->dev, "No cache defaults, reading back from HW\n");
 
 		/* Bypass the cache access till data read from HW */
 		map->cache_bypass = true;
@@ -223,7 +223,8 @@ int regcache_init(struct regmap *map, const struct regmap_config *config)
 			goto err_free;
 	}
 
-	if (map->num_reg_defaults && map->cache_ops->populate) {
+	if (map->cache_ops->populate &&
+	    (map->num_reg_defaults || map->reg_default_cb)) {
 		dev_dbg(map->dev, "Populating %s cache\n", map->cache_ops->name);
 		map->lock(map->lock_arg);
 		ret = map->cache_ops->populate(map);
diff --git a/drivers/base/regmap/regmap-kunit.c b/drivers/base/regmap/regmap-kunit.c
index f6fc5ed016da..6d8279de3ff2 100644
--- a/drivers/base/regmap/regmap-kunit.c
+++ b/drivers/base/regmap/regmap-kunit.c
@@ -15,6 +15,8 @@ KUNIT_DEFINE_ACTION_WRAPPER(regmap_exit_action, regmap_exit, struct regmap *);
 
 struct regmap_test_priv {
 	struct device *dev;
+	bool *reg_default_called;
+	unsigned int reg_default_max;
 };
 
 struct regmap_test_param {
@@ -118,6 +120,14 @@ static const struct regmap_test_param real_cache_types_only_list[] = {
 
 KUNIT_ARRAY_PARAM(real_cache_types_only, real_cache_types_only_list, param_to_desc);
 
+static const struct regmap_test_param flat_cache_types_list[] = {
+	{ .cache = REGCACHE_FLAT, .from_reg = 0 },
+	{ .cache = REGCACHE_FLAT, .from_reg = 0, .fast_io = true },
+	{ .cache = REGCACHE_FLAT, .from_reg = 0x2001 },
+};
+
+KUNIT_ARRAY_PARAM(flat_cache_types, flat_cache_types_list, param_to_desc);
+
 static const struct regmap_test_param real_cache_types_list[] = {
 	{ .cache = REGCACHE_FLAT,   .from_reg = 0 },
 	{ .cache = REGCACHE_FLAT,   .from_reg = 0, .fast_io = true },
@@ -248,6 +258,37 @@ static bool reg_5_false(struct device *dev, unsigned int reg)
 	return reg != (param->from_reg + 5);
 }
 
+static unsigned int reg_default_expected(unsigned int reg)
+{
+	return 0x5a5a0000 | (reg & 0xffff);
+}
+
+static int reg_default_test_cb(struct device *dev, unsigned int reg,
+			       unsigned int *def)
+{
+	struct kunit *test = dev_get_drvdata(dev);
+	struct regmap_test_priv *priv = test->priv;
+
+	if (priv && priv->reg_default_called && reg <= priv->reg_default_max)
+		priv->reg_default_called[reg] = true;
+
+	*def = reg_default_expected(reg);
+	return 0;
+}
+
+static void expect_reg_default_value(struct kunit *test, struct regmap *map,
+				     struct regmap_ram_data *data,
+				     struct regmap_test_priv *priv,
+				     unsigned int reg)
+{
+	unsigned int val;
+
+	KUNIT_EXPECT_TRUE(test, priv->reg_default_called[reg]);
+	KUNIT_EXPECT_EQ(test, 0, regmap_read(map, reg, &val));
+	KUNIT_EXPECT_EQ(test, reg_default_expected(reg), val);
+	KUNIT_EXPECT_FALSE(test, data->read[reg]);
+}
+
 static void basic_read_write(struct kunit *test)
 {
 	struct regmap *map;
@@ -628,6 +669,54 @@ static void reg_defaults(struct kunit *test)
 		KUNIT_EXPECT_EQ(test, config.cache_type == REGCACHE_NONE, data->read[i]);
 }
 
+static void reg_default_callback_populates_flat_cache(struct kunit *test)
+{
+	const struct regmap_test_param *param = test->param_value;
+	struct regmap_test_priv *priv = test->priv;
+	struct regmap *map;
+	struct regmap_config config;
+	struct regmap_ram_data *data;
+	unsigned int reg, val;
+	unsigned int defaults_end;
+
+	config = test_regmap_config;
+	config.num_reg_defaults = 3;
+	config.max_register = param->from_reg + BLOCK_TEST_SIZE - 1;
+	config.reg_default_cb = reg_default_test_cb;
+
+	priv->reg_default_max = config.max_register;
+	priv->reg_default_called = kunit_kcalloc(test, config.max_register + 1,
+						 sizeof(*priv->reg_default_called),
+						 GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, priv->reg_default_called);
+
+	map = gen_regmap(test, &config, &data);
+	KUNIT_ASSERT_FALSE(test, IS_ERR(map));
+	if (IS_ERR(map))
+		return;
+
+	for (reg = 0; reg <= config.max_register; reg++)
+		data->read[reg] = false;
+
+	defaults_end = param->from_reg + config.num_reg_defaults - 1;
+
+	for (reg = param->from_reg; reg <= defaults_end; reg++) {
+		KUNIT_EXPECT_FALSE(test, priv->reg_default_called[reg]);
+		KUNIT_EXPECT_EQ(test, 0, regmap_read(map, reg, &val));
+		KUNIT_EXPECT_EQ(test, data->vals[reg], val);
+		KUNIT_EXPECT_FALSE(test, data->read[reg]);
+	}
+
+	if (param->from_reg > 0)
+		expect_reg_default_value(test, map, data, priv, 0);
+
+	if (defaults_end + 1 <= config.max_register)
+		expect_reg_default_value(test, map, data, priv, defaults_end + 1);
+
+	if (config.max_register > defaults_end + 1)
+		expect_reg_default_value(test, map, data, priv, config.max_register);
+}
+
 static void reg_defaults_read_dev(struct kunit *test)
 {
 	struct regmap *map;
@@ -2058,6 +2147,8 @@ static struct kunit_case regmap_test_cases[] = {
 	KUNIT_CASE_PARAM(write_readonly, regcache_types_gen_params),
 	KUNIT_CASE_PARAM(read_writeonly, regcache_types_gen_params),
 	KUNIT_CASE_PARAM(reg_defaults, regcache_types_gen_params),
+	KUNIT_CASE_PARAM(reg_default_callback_populates_flat_cache,
+			 flat_cache_types_gen_params),
 	KUNIT_CASE_PARAM(reg_defaults_read_dev, regcache_types_gen_params),
 	KUNIT_CASE_PARAM(register_patch, regcache_types_gen_params),
 	KUNIT_CASE_PARAM(stride, regcache_types_gen_params),
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index ae2215d4e61c..4231e9d4b8ff 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -813,6 +813,7 @@ struct regmap *__regmap_init(struct device *dev,
 	map->precious_reg = config->precious_reg;
 	map->writeable_noinc_reg = config->writeable_noinc_reg;
 	map->readable_noinc_reg = config->readable_noinc_reg;
+	map->reg_default_cb = config->reg_default_cb;
 	map->cache_type = config->cache_type;
 
 	spin_lock_init(&map->async_lock);
@@ -1435,6 +1436,7 @@ int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
 	map->precious_reg = config->precious_reg;
 	map->writeable_noinc_reg = config->writeable_noinc_reg;
 	map->readable_noinc_reg = config->readable_noinc_reg;
+	map->reg_default_cb = config->reg_default_cb;
 	map->cache_type = config->cache_type;
 
 	ret = regmap_set_name(map, config);