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Commit 141eba2e authored by Stephen Warren's avatar Stephen Warren Committed by Mark Brown
Browse files

regmap: allow busses to request formatting with specific endianness 



Add a field to struct regmap_bus that allows bus drivers to request that
register addresses and values be formatted with a specific endianness.

The default endianness is unchanged from current operation: Big.

Implement native endian formatting/parsing for 16- and 32-bit values.
This will be enough to support regmap-mmio.c.

Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent f8f5701b

drivers/base/regmap/regmap.c

+90 −11
Original line number Diff line number Diff line
@@ -119,13 +119,19 @@ static void regmap_format_8(void *buf, unsigned int val, unsigned int shift) 
	b[0] = val << shift;

}



static void regmap_format_16(void *buf, unsigned int val, unsigned int shift)

static void regmap_format_16_be(void *buf, unsigned int val, unsigned int shift)

{

	__be16 *b = buf;



	b[0] = cpu_to_be16(val << shift);

}



static void regmap_format_16_native(void *buf, unsigned int val,

				    unsigned int shift)

{

	*(u16 *)buf = val << shift;

}



static void regmap_format_24(void *buf, unsigned int val, unsigned int shift)

{

	u8 *b = buf;
@@ -137,13 +143,19 @@ static void regmap_format_24(void *buf, unsigned int val, unsigned int shift) 
	b[2] = val;

}



static void regmap_format_32(void *buf, unsigned int val, unsigned int shift)

static void regmap_format_32_be(void *buf, unsigned int val, unsigned int shift)

{

	__be32 *b = buf;



	b[0] = cpu_to_be32(val << shift);

}



static void regmap_format_32_native(void *buf, unsigned int val,

				    unsigned int shift)

{

	*(u32 *)buf = val << shift;

}



static unsigned int regmap_parse_8(void *buf)

{

	u8 *b = buf;
@@ -151,7 +163,7 @@ static unsigned int regmap_parse_8(void *buf) 
	return b[0];

}



static unsigned int regmap_parse_16(void *buf)

static unsigned int regmap_parse_16_be(void *buf)

{

	__be16 *b = buf;
@@ -160,6 +172,11 @@ static unsigned int regmap_parse_16(void *buf) 
	return b[0];

}



static unsigned int regmap_parse_16_native(void *buf)

{

	return *(u16 *)buf;

}



static unsigned int regmap_parse_24(void *buf)

{

	u8 *b = buf;
@@ -170,7 +187,7 @@ static unsigned int regmap_parse_24(void *buf) 
	return ret;

}



static unsigned int regmap_parse_32(void *buf)

static unsigned int regmap_parse_32_be(void *buf)

{

	__be32 *b = buf;
@@ -179,6 +196,11 @@ static unsigned int regmap_parse_32(void *buf) 
	return b[0];

}



static unsigned int regmap_parse_32_native(void *buf)

{

	return *(u32 *)buf;

}



static void regmap_lock_mutex(struct regmap *map)

{

	mutex_lock(&map->mutex);
@@ -227,6 +249,7 @@ struct regmap *regmap_init(struct device *dev, 
{

	struct regmap *map, **m;

	int ret = -EINVAL;

	enum regmap_endian reg_endian, val_endian;



	if (!bus || !config)

		goto err;
@@ -275,6 +298,18 @@ struct regmap *regmap_init(struct device *dev, 
		map->read_flag_mask = bus->read_flag_mask;

	}



	reg_endian = config->reg_format_endian;

	if (reg_endian == REGMAP_ENDIAN_DEFAULT)

		reg_endian = bus->reg_format_endian_default;

	if (reg_endian == REGMAP_ENDIAN_DEFAULT)

		reg_endian = REGMAP_ENDIAN_BIG;



	val_endian = config->val_format_endian;

	if (val_endian == REGMAP_ENDIAN_DEFAULT)

		val_endian = bus->val_format_endian_default;

	if (val_endian == REGMAP_ENDIAN_DEFAULT)

		val_endian = REGMAP_ENDIAN_BIG;



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

	case 2:

		switch (config->val_bits) {
@@ -321,11 +356,29 @@ struct regmap *regmap_init(struct device *dev, 
		break;



	case 16:

		map->format.format_reg = regmap_format_16;

		switch (reg_endian) {

		case REGMAP_ENDIAN_BIG:

			map->format.format_reg = regmap_format_16_be;

			break;

		case REGMAP_ENDIAN_NATIVE:

			map->format.format_reg = regmap_format_16_native;

			break;

		default:

			goto err_map;

		}

		break;



	case 32:

		map->format.format_reg = regmap_format_32;

		switch (reg_endian) {

		case REGMAP_ENDIAN_BIG:

			map->format.format_reg = regmap_format_32_be;

			break;

		case REGMAP_ENDIAN_NATIVE:

			map->format.format_reg = regmap_format_32_native;

			break;

		default:

			goto err_map;

		}

		break;



	default:
@@ -338,21 +391,47 @@ struct regmap *regmap_init(struct device *dev, 
		map->format.parse_val = regmap_parse_8;

		break;

	case 16:

		map->format.format_val = regmap_format_16;

		map->format.parse_val = regmap_parse_16;

		switch (val_endian) {

		case REGMAP_ENDIAN_BIG:

			map->format.format_val = regmap_format_16_be;

			map->format.parse_val = regmap_parse_16_be;

			break;

		case REGMAP_ENDIAN_NATIVE:

			map->format.format_val = regmap_format_16_native;

			map->format.parse_val = regmap_parse_16_native;

			break;

		default:

			goto err_map;

		}

		break;

	case 24:

		if (val_endian != REGMAP_ENDIAN_BIG)

			goto err_map;

		map->format.format_val = regmap_format_24;

		map->format.parse_val = regmap_parse_24;

		break;

	case 32:

		map->format.format_val = regmap_format_32;

		map->format.parse_val = regmap_parse_32;

		switch (val_endian) {

		case REGMAP_ENDIAN_BIG:

			map->format.format_val = regmap_format_32_be;

			map->format.parse_val = regmap_parse_32_be;

			break;

		case REGMAP_ENDIAN_NATIVE:

			map->format.format_val = regmap_format_32_native;

			map->format.parse_val = regmap_parse_32_native;

			break;

		default:

			goto err_map;

		}

		break;

	}



	if (map->format.format_write)

	if (map->format.format_write) {

		if ((reg_endian != REGMAP_ENDIAN_BIG) ||

		    (val_endian != REGMAP_ENDIAN_BIG))

			goto err_map;

		map->use_single_rw = true;

	}



	if (!map->format.format_write &&

	    !(map->format.format_reg && map->format.format_val))

include/linux/regmap.h

+25 −0
Original line number Diff line number Diff line
@@ -43,6 +43,14 @@ struct reg_default { 


#ifdef CONFIG_REGMAP



enum regmap_endian {

	/* Unspecified -> 0 -> Backwards compatible default */

	REGMAP_ENDIAN_DEFAULT = 0,

	REGMAP_ENDIAN_BIG,

	REGMAP_ENDIAN_LITTLE,

	REGMAP_ENDIAN_NATIVE,

};



/**

 * Configuration for the register map of a device.

 *
@@ -84,6 +92,12 @@ struct reg_default { 
 * @reg_defaults_raw: Power on reset values for registers (for use with

 *                    register cache support).

 * @num_reg_defaults_raw: Number of elements in reg_defaults_raw.

 * @reg_format_endian: Endianness for formatted register addresses. If this is

 *                     DEFAULT, the @reg_format_endian_default value from the

 *                     regmap bus is used.

 * @val_format_endian: Endianness for formatted register values. If this is

 *                     DEFAULT, the @reg_format_endian_default value from the

 *                     regmap bus is used.

 */

struct regmap_config {

	const char *name;
@@ -109,6 +123,9 @@ struct regmap_config { 
	u8 write_flag_mask;



	bool use_single_rw;



	enum regmap_endian reg_format_endian;

	enum regmap_endian val_format_endian;

};



typedef int (*regmap_hw_write)(void *context, const void *data,
@@ -133,6 +150,12 @@ typedef void (*regmap_hw_free_context)(void *context); 
 *         data.

 * @read_flag_mask: Mask to be set in the top byte of the register when doing

 *                  a read.

 * @reg_format_endian_default: Default endianness for formatted register

 *     addresses. Used when the regmap_config specifies DEFAULT. If this is

 *     DEFAULT, BIG is assumed.

 * @val_format_endian_default: Default endianness for formatted register

 *     values. Used when the regmap_config specifies DEFAULT. If this is

 *     DEFAULT, BIG is assumed.

 */

struct regmap_bus {

	bool fast_io;
@@ -141,6 +164,8 @@ struct regmap_bus { 
	regmap_hw_read read;

	regmap_hw_free_context free_context;

	u8 read_flag_mask;

	enum regmap_endian reg_format_endian_default;

	enum regmap_endian val_format_endian_default;

};



struct regmap *regmap_init(struct device *dev,