[PATCH] regmap-i2c: Set regmap max raw r/w from quirks

[PATCH] regmap-i2c: Set regmap max raw r/w from quirks

[Lucas Tanure]

Set regmap raw read/write from i2c quirks max read/write
so regmap_raw_read/write can split the access into chunks

Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
---
 drivers/base/regmap/regmap-i2c.c | 45 +++++++++++++++++++++++++++-----
 drivers/base/regmap/regmap.c     |  2 ++
 include/linux/regmap.h           |  2 ++
 3 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/drivers/base/regmap/regmap-i2c.c b/drivers/base/regmap/regmap-i2c.c
index 62b95a9212ae..980e5ce6a3a3 100644
--- a/drivers/base/regmap/regmap-i2c.c
+++ b/drivers/base/regmap/regmap-i2c.c
@@ -306,33 +306,64 @@ static const struct regmap_bus regmap_i2c_smbus_i2c_block_reg16 = {
 static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c,
 					const struct regmap_config *config)
 {
+	const struct i2c_adapter_quirks *quirks;
+	const struct regmap_bus *bus = NULL;
+	struct regmap_bus *ret_bus;
+	u16 max_read = 0, max_write = 0;
+
 	if (i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C))
-		return &regmap_i2c;
+		bus = &regmap_i2c;
 	else if (config->val_bits == 8 && config->reg_bits == 8 &&
 		 i2c_check_functionality(i2c->adapter,
 					 I2C_FUNC_SMBUS_I2C_BLOCK))
-		return &regmap_i2c_smbus_i2c_block;
+		bus = &regmap_i2c_smbus_i2c_block;
 	else if (config->val_bits == 8 && config->reg_bits == 16 &&
 		i2c_check_functionality(i2c->adapter,
 					I2C_FUNC_SMBUS_I2C_BLOCK))
-		return &regmap_i2c_smbus_i2c_block_reg16;
+		bus = &regmap_i2c_smbus_i2c_block_reg16;
 	else if (config->val_bits == 16 && config->reg_bits == 8 &&
 		 i2c_check_functionality(i2c->adapter,
 					 I2C_FUNC_SMBUS_WORD_DATA))
 		switch (regmap_get_val_endian(&i2c->dev, NULL, config)) {
 		case REGMAP_ENDIAN_LITTLE:
-			return &regmap_smbus_word;
+			bus = &regmap_smbus_word;
+			break;
 		case REGMAP_ENDIAN_BIG:
-			return &regmap_smbus_word_swapped;
+			bus = &regmap_smbus_word_swapped;
+			break;
 		default:		/* everything else is not supported */
 			break;
 		}
 	else if (config->val_bits == 8 && config->reg_bits == 8 &&
 		 i2c_check_functionality(i2c->adapter,
 					 I2C_FUNC_SMBUS_BYTE_DATA))
-		return &regmap_smbus_byte;
+		bus = &regmap_smbus_byte;
+
+	if (!bus)
+		return ERR_PTR(-ENOTSUPP);
+
+	quirks = i2c->adapter->quirks;
+	if (quirks) {
+		if (quirks->max_read_len &&
+		    (bus->max_raw_read == 0 || bus->max_raw_read > quirks->max_read_len))
+			max_read = quirks->max_read_len;
+
+		if (quirks->max_write_len &&
+		    (bus->max_raw_write == 0 || bus->max_raw_write > quirks->max_write_len))
+			max_write = quirks->max_write_len;
+
+		if (max_read || max_write) {
+			ret_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL);
+			if (!ret_bus)
+				return ERR_PTR(-ENOMEM);
+			ret_bus->free_on_exit = true;
+			ret_bus->max_raw_read = max_read;
+			ret_bus->max_raw_write = max_write;
+			bus = ret_bus;
+		}
+	}
 
-	return ERR_PTR(-ENOTSUPP);
+	return bus;
 }
 
 struct regmap *__regmap_init_i2c(struct i2c_client *i2c,
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 297e95be25b3..0d185ec018a5 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1496,6 +1496,8 @@ void regmap_exit(struct regmap *map)
 		mutex_destroy(&map->mutex);
 	kfree_const(map->name);
 	kfree(map->patch);
+	if (map->bus && map->bus->free_on_exit)
+		kfree(map->bus);
 	kfree(map);
 }
 EXPORT_SYMBOL_GPL(regmap_exit);
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index f87a11a5cc4a..8c16e6fa0f66 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -502,6 +502,7 @@ typedef void (*regmap_hw_free_context)(void *context);
  *     DEFAULT, BIG is assumed.
  * @max_raw_read: Max raw read size that can be used on the bus.
  * @max_raw_write: Max raw write size that can be used on the bus.
+ * @free_on_exit: kfree this on exit of regmap
  */
 struct regmap_bus {
 	bool fast_io;
@@ -519,6 +520,7 @@ struct regmap_bus {
 	enum regmap_endian val_format_endian_default;
 	size_t max_raw_read;
 	size_t max_raw_write;
+	bool free_on_exit;
 };
 
 /*
-- 
2.31.1

Re: [PATCH] regmap-i2c: Set regmap max raw r/w from quirks

[Mark Brown]

On Wed, 12 May 2021 14:52:22 +0100, Lucas Tanure wrote:
> Set regmap raw read/write from i2c quirks max read/write
> so regmap_raw_read/write can split the access into chunks

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

Thanks!

[1/1] regmap-i2c: Set regmap max raw r/w from quirks
      commit: ea030ca688193462b8d612c1628c37129aa30072

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark