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Unverified Commit e594a063 authored by Mark Brown's avatar Mark Brown
Browse files

Merge tag 'regmap-sccb' of... 

Merge tag 'regmap-sccb' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap into regmap-4.19

regmap: Add support for SCCB

This is an I2C subset.
parents e76ad18b bcf7eac3

drivers/base/regmap/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -45,3 +45,7 @@ config REGMAP_IRQ 
config REGMAP_SOUNDWIRE

	tristate

	depends on SOUNDWIRE_BUS



config REGMAP_SCCB

	tristate

	depends on I2C

drivers/base/regmap/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -15,3 +15,4 @@ obj-$(CONFIG_REGMAP_MMIO) += regmap-mmio.o 
obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o

obj-$(CONFIG_REGMAP_W1) += regmap-w1.o

obj-$(CONFIG_REGMAP_SOUNDWIRE) += regmap-sdw.o

obj-$(CONFIG_REGMAP_SCCB) += regmap-sccb.o

drivers/base/regmap/regmap-sccb.c

0 → 100644
+128 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Register map access API - SCCB support



#include <linux/regmap.h>

#include <linux/i2c.h>

#include <linux/module.h>



#include "internal.h"



/**

 * sccb_is_available - Check if the adapter supports SCCB protocol

 * @adap: I2C adapter

 *

 * Return true if the I2C adapter is capable of using SCCB helper functions,

 * false otherwise.

 */

static bool sccb_is_available(struct i2c_adapter *adap)

{

	u32 needed_funcs = I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE_DATA;



	/*

	 * If we ever want support for hardware doing SCCB natively, we will

	 * introduce a sccb_xfer() callback to struct i2c_algorithm and check

	 * for it here.

	 */



	return (i2c_get_functionality(adap) & needed_funcs) == needed_funcs;

}



/**

 * regmap_sccb_read - Read data from SCCB slave device

 * @context: Device that will be interacted wit

 * @reg: Register to be read from

 * @val: Pointer to store read value

 *

 * This executes the 2-phase write transmission cycle that is followed by a

 * 2-phase read transmission cycle, returning negative errno else zero on

 * success.

 */

static int regmap_sccb_read(void *context, unsigned int reg, unsigned int *val)

{

	struct device *dev = context;

	struct i2c_client *i2c = to_i2c_client(dev);

	int ret;

	union i2c_smbus_data data;



	i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);



	ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags,

			       I2C_SMBUS_WRITE, reg, I2C_SMBUS_BYTE, NULL);

	if (ret < 0)

		goto out;



	ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags,

			       I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &data);

	if (ret < 0)

		goto out;



	*val = data.byte;

out:

	i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);



	return ret;

}



/**

 * regmap_sccb_write - Write data to SCCB slave device

 * @context: Device that will be interacted wit

 * @reg: Register to write to

 * @val: Value to be written

 *

 * This executes the SCCB 3-phase write transmission cycle, returning negative

 * errno else zero on success.

 */

static int regmap_sccb_write(void *context, unsigned int reg, unsigned int val)

{

	struct device *dev = context;

	struct i2c_client *i2c = to_i2c_client(dev);



	return i2c_smbus_write_byte_data(i2c, reg, val);

}



static struct regmap_bus regmap_sccb_bus = {

	.reg_write = regmap_sccb_write,

	.reg_read = regmap_sccb_read,

};



static const struct regmap_bus *regmap_get_sccb_bus(struct i2c_client *i2c,

					const struct regmap_config *config)

{

	if (config->val_bits == 8 && config->reg_bits == 8 &&

			sccb_is_available(i2c->adapter))

		return &regmap_sccb_bus;



	return ERR_PTR(-ENOTSUPP);

}



struct regmap *__regmap_init_sccb(struct i2c_client *i2c,

				  const struct regmap_config *config,

				  struct lock_class_key *lock_key,

				  const char *lock_name)

{

	const struct regmap_bus *bus = regmap_get_sccb_bus(i2c, config);



	if (IS_ERR(bus))

		return ERR_CAST(bus);



	return __regmap_init(&i2c->dev, bus, &i2c->dev, config,

			     lock_key, lock_name);

}

EXPORT_SYMBOL_GPL(__regmap_init_sccb);



struct regmap *__devm_regmap_init_sccb(struct i2c_client *i2c,

				       const struct regmap_config *config,

				       struct lock_class_key *lock_key,

				       const char *lock_name)

{

	const struct regmap_bus *bus = regmap_get_sccb_bus(i2c, config);



	if (IS_ERR(bus))

		return ERR_CAST(bus);



	return __devm_regmap_init(&i2c->dev, bus, &i2c->dev, config,

				  lock_key, lock_name);

}

EXPORT_SYMBOL_GPL(__devm_regmap_init_sccb);



MODULE_LICENSE("GPL v2");

include/linux/regmap.h

+35 −0
Original line number Diff line number Diff line
@@ -514,6 +514,10 @@ struct regmap *__regmap_init_i2c(struct i2c_client *i2c, 
				 const struct regmap_config *config,

				 struct lock_class_key *lock_key,

				 const char *lock_name);

struct regmap *__regmap_init_sccb(struct i2c_client *i2c,

				  const struct regmap_config *config,

				  struct lock_class_key *lock_key,

				  const char *lock_name);

struct regmap *__regmap_init_slimbus(struct slim_device *slimbus,

				 const struct regmap_config *config,

				 struct lock_class_key *lock_key,
@@ -558,6 +562,10 @@ struct regmap *__devm_regmap_init_i2c(struct i2c_client *i2c, 
				      const struct regmap_config *config,

				      struct lock_class_key *lock_key,

				      const char *lock_name);

struct regmap *__devm_regmap_init_sccb(struct i2c_client *i2c,

				       const struct regmap_config *config,

				       struct lock_class_key *lock_key,

				       const char *lock_name);

struct regmap *__devm_regmap_init_spi(struct spi_device *dev,

				      const struct regmap_config *config,

				      struct lock_class_key *lock_key,
@@ -645,6 +653,19 @@ int regmap_attach_dev(struct device *dev, struct regmap *map, 
	__regmap_lockdep_wrapper(__regmap_init_i2c, #config,		\

				i2c, config)



/**

 * regmap_init_sccb() - Initialise register map

 *

 * @i2c: Device that will be interacted with

 * @config: Configuration for register map

 *

 * The return value will be an ERR_PTR() on error or a valid pointer to

 * a struct regmap.

 */

#define regmap_init_sccb(i2c, config)					\

	__regmap_lockdep_wrapper(__regmap_init_sccb, #config,		\

				i2c, config)



/**

 * regmap_init_slimbus() - Initialise register map

 *
@@ -797,6 +818,20 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg); 
	__regmap_lockdep_wrapper(__devm_regmap_init_i2c, #config,	\

				i2c, config)



/**

 * devm_regmap_init_sccb() - Initialise managed register map

 *

 * @i2c: Device that will be interacted with

 * @config: Configuration for register map

 *

 * The return value will be an ERR_PTR() on error or a valid pointer

 * to a struct regmap.  The regmap will be automatically freed by the

 * device management code.

 */

#define devm_regmap_init_sccb(i2c, config)				\

	__regmap_lockdep_wrapper(__devm_regmap_init_sccb, #config,	\

				i2c, config)



/**

 * devm_regmap_init_spi() - Initialise register map

 *