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  •  * Freescale i.MXS Register Accessors
    
     *
     * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
     * on behalf of DENX Software Engineering GmbH
     *
    
     * SPDX-License-Identifier:	GPL-2.0+
    
    #ifndef __MXS_REGS_COMMON_H__
    #define __MXS_REGS_COMMON_H__
    
     * The i.MXS has interesting feature when it comes to register access. There
    
     * are four kinds of access to one particular register. Those are:
     *
     * 1) Common read/write access. To use this mode, just write to the address of
     *    the register.
     * 2) Set bits only access. To set bits, write which bits you want to set to the
     *    address of the register + 0x4.
     * 3) Clear bits only access. To clear bits, write which bits you want to clear
     *    to the address of the register + 0x8.
     * 4) Toggle bits only access. To toggle bits, write which bits you want to
     *    toggle to the address of the register + 0xc.
     *
     * IMPORTANT NOTE: Not all registers support accesses 2-4! Also, not all bits
     * can be set/cleared by pure write as in access type 1, some need to be
     * explicitly set/cleared by using access type 2-3.
     *
     * The following macros and structures allow the user to either access the
     * register in all aforementioned modes (by accessing reg_name, reg_name_set,
     * reg_name_clr, reg_name_tog) or pass the register structure further into
     * various functions with correct type information (by accessing reg_name_reg).
     *
     */
    
    
    #define	__mxs_reg_8(name)		\
    
    	uint8_t	name[4];		\
    	uint8_t	name##_set[4];		\
    	uint8_t	name##_clr[4];		\
    	uint8_t	name##_tog[4];		\
    
    
    #define	__mxs_reg_32(name)		\
    
    	uint32_t name;			\
    	uint32_t name##_set;		\
    	uint32_t name##_clr;		\
    	uint32_t name##_tog;
    
    
    struct mxs_register_8 {
    	__mxs_reg_8(reg)
    
    struct mxs_register_32 {
    	__mxs_reg_32(reg)
    
    #define	mxs_reg_8(name)				\
    
    		struct { __mxs_reg_8(name) };		\
    		struct mxs_register_8 name##_reg;	\
    
    #define	mxs_reg_32(name)				\
    
    	union {						\
    
    		struct { __mxs_reg_32(name) };		\
    		struct mxs_register_32 name##_reg;	\
    
    #endif	/* __MXS_REGS_COMMON_H__ */