arch/arm/include/asm/imx-common/regs-common.h

   1 /*
   2  * Freescale i.MXS Register Accessors
   3  *
   4  * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
   5  * on behalf of DENX Software Engineering GmbH
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #ifndef __MXS_REGS_COMMON_H__
  11 #define __MXS_REGS_COMMON_H__
  12
  13 #include <linux/types.h>
  14
  15 /*
  16  * The i.MXS has interesting feature when it comes to register access. There
  17  * are four kinds of access to one particular register. Those are:
  18  *
  19  * 1) Common read/write access. To use this mode, just write to the address of
  20  *    the register.
  21  * 2) Set bits only access. To set bits, write which bits you want to set to the
  22  *    address of the register + 0x4.
  23  * 3) Clear bits only access. To clear bits, write which bits you want to clear
  24  *    to the address of the register + 0x8.
  25  * 4) Toggle bits only access. To toggle bits, write which bits you want to
  26  *    toggle to the address of the register + 0xc.
  27  *
  28  * IMPORTANT NOTE: Not all registers support accesses 2-4! Also, not all bits
  29  * can be set/cleared by pure write as in access type 1, some need to be
  30  * explicitly set/cleared by using access type 2-3.
  31  *
  32  * The following macros and structures allow the user to either access the
  33  * register in all aforementioned modes (by accessing reg_name, reg_name_set,
  34  * reg_name_clr, reg_name_tog) or pass the register structure further into
  35  * various functions with correct type information (by accessing reg_name_reg).
  36  *
  37  */
  38
  39 #define __mxs_reg_8(name)               \
  40         uint8_t name[4];                \
  41         uint8_t name##_set[4];          \
  42         uint8_t name##_clr[4];          \
  43         uint8_t name##_tog[4];          \
  44
  45 #define __mxs_reg_32(name)              \
  46         uint32_t name;                  \
  47         uint32_t name##_set;            \
  48         uint32_t name##_clr;            \
  49         uint32_t name##_tog;
  50
  51 struct mxs_register_8 {
  52         __mxs_reg_8(reg)
  53 };
  54
  55 struct mxs_register_32 {
  56         __mxs_reg_32(reg)
  57 };
  58
  59 #define mxs_reg_8(name)                         \
  60         union {                                         \
  61                 struct { __mxs_reg_8(name) };           \
  62                 struct mxs_register_8 name##_reg;       \
  63         };
  64
  65 #define mxs_reg_32(name)                                \
  66         union {                                         \
  67                 struct { __mxs_reg_32(name) };          \
  68                 struct mxs_register_32 name##_reg;      \
  69         };
  70
  71 #endif  /* __MXS_REGS_COMMON_H__ */