Commit 6ba42ba6 authored by Mark Brown's avatar Mark Brown
Browse files

Merge tag 'dt-endian' of... 

Merge tag 'dt-endian' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap into spi-fsl-dspi

regmap: Device tree endianness support

This adds generic support for specifying endianess for register map in
the DT.
parents c99428d0 cf673fbc

drivers/base/regmap/regmap.c

+50 −93
Original line number Diff line number Diff line
@@ -449,100 +449,64 @@ int regmap_attach_dev(struct device *dev, struct regmap *map, 
}

EXPORT_SYMBOL_GPL(regmap_attach_dev);



enum regmap_endian_type {

	REGMAP_ENDIAN_REG,

	REGMAP_ENDIAN_VAL,

};

static enum regmap_endian regmap_get_reg_endian(const struct regmap_bus *bus,

					const struct regmap_config *config)

{

	enum regmap_endian endian;



	/* Retrieve the endianness specification from the regmap config */

	endian = config->reg_format_endian;



	/* If the regmap config specified a non-default value, use that */

	if (endian != REGMAP_ENDIAN_DEFAULT)

		return endian;



	/* Retrieve the endianness specification from the bus config */

	if (bus && bus->reg_format_endian_default)

		endian = bus->reg_format_endian_default;



static int of_regmap_get_endian(struct device *dev,

	/* If the bus specified a non-default value, use that */

	if (endian != REGMAP_ENDIAN_DEFAULT)

		return endian;



	/* Use this if no other value was found */

	return REGMAP_ENDIAN_BIG;

}



static enum regmap_endian regmap_get_val_endian(struct device *dev,

					const struct regmap_bus *bus,

				const struct regmap_config *config,

				enum regmap_endian_type type,

				enum regmap_endian *endian)

					const struct regmap_config *config)

{

	struct device_node *np = dev->of_node;

	enum regmap_endian endian;



	if (!endian || !config)

		return -EINVAL;

	/* Retrieve the endianness specification from the regmap config */

	endian = config->val_format_endian;



	/*

	 * Firstly, try to parse the endianness from driver's config,

	 * this is to be compatible with the none DT or the old drivers.

	 * From the driver's config the endianness value maybe:

	 *   REGMAP_ENDIAN_BIG,

	 *   REGMAP_ENDIAN_LITTLE,

	 *   REGMAP_ENDIAN_NATIVE,

	 *   REGMAP_ENDIAN_DEFAULT.

	 */

	switch (type) {

	case REGMAP_ENDIAN_REG:

		*endian = config->reg_format_endian;

		break;

	case REGMAP_ENDIAN_VAL:

		*endian = config->val_format_endian;

		break;

	default:

		return -EINVAL;

	}

	/* If the regmap config specified a non-default value, use that */

	if (endian != REGMAP_ENDIAN_DEFAULT)

		return endian;



	/*

	 * If the endianness parsed from driver config is

	 * REGMAP_ENDIAN_DEFAULT, that means maybe we are using the DT

	 * node to specify the endianness information.

	 */

	if (*endian != REGMAP_ENDIAN_DEFAULT)

		return 0;



	/*

	 * Secondly, try to parse the endianness from DT node if the

	 * driver config does not specify it.

	 * From the DT node the endianness value maybe:

	 *   REGMAP_ENDIAN_BIG,

	 *   REGMAP_ENDIAN_LITTLE,

	 *   REGMAP_ENDIAN_NATIVE,

	 */

	switch (type) {

	case REGMAP_ENDIAN_VAL:

	/* Parse the device's DT node for an endianness specification */

	if (of_property_read_bool(np, "big-endian"))

			*endian = REGMAP_ENDIAN_BIG;

		endian = REGMAP_ENDIAN_BIG;

	else if (of_property_read_bool(np, "little-endian"))

			*endian = REGMAP_ENDIAN_LITTLE;

		else

			*endian = REGMAP_ENDIAN_NATIVE;

		break;

	case REGMAP_ENDIAN_REG:

		break;

	default:

		return -EINVAL;

	}

		endian = REGMAP_ENDIAN_LITTLE;



	/*

	 * If the endianness parsed from DT node is REGMAP_ENDIAN_NATIVE, that

	 * maybe means the DT does not care the endianness or it should use

	 * the regmap bus's default endianness, then we should try to check

	 * whether the regmap bus has specified the default endianness.

	 */

	if (*endian != REGMAP_ENDIAN_NATIVE)

		return 0;

	/* If the endianness was specified in DT, use that */

	if (endian != REGMAP_ENDIAN_DEFAULT)

		return endian;



	/*

	 * Finally, try to parse the endianness from regmap bus config

	 * if in device's DT node the endianness property is absent.

	 */

	switch (type) {

	case REGMAP_ENDIAN_REG:

		if (bus && bus->reg_format_endian_default)

			*endian = bus->reg_format_endian_default;

		break;

	case REGMAP_ENDIAN_VAL:

	/* Retrieve the endianness specification from the bus config */

	if (bus && bus->val_format_endian_default)

			*endian = bus->val_format_endian_default;

		break;

	default:

		return -EINVAL;

	}

		endian = bus->val_format_endian_default;



	return 0;

	/* If the bus specified a non-default value, use that */

	if (endian != REGMAP_ENDIAN_DEFAULT)

		return endian;



	/* Use this if no other value was found */

	return REGMAP_ENDIAN_BIG;

}



/**
@@ -648,15 +612,8 @@ struct regmap *regmap_init(struct device *dev, 
		map->reg_read  = _regmap_bus_read;

	}



	ret = of_regmap_get_endian(dev, bus, config, REGMAP_ENDIAN_REG,

				   &reg_endian);

	if (ret)

		return ERR_PTR(ret);



	ret = of_regmap_get_endian(dev, bus, config, REGMAP_ENDIAN_VAL,

				   &val_endian);

	if (ret)

		return ERR_PTR(ret);

	reg_endian = regmap_get_reg_endian(bus, config);

	val_endian = regmap_get_val_endian(dev, bus, config);



	switch (config->reg_bits + map->reg_shift) {

	case 2: