u-boot/arch/arm/include/asm/arch-mx28/regs-common.h
Robert Delien 531bb825fd Introducing 8-bit wide register, mx28_register_8
This patch introduces an 8-bit register, mx28_register_8, in order to
prepare for fixing erroneous 32-bit wide access of registers
hw_clkctrl_frac0 and hw_clkctrl_frac1.

Signed-off-by: Robert Delien <robert@delien.nl>
Acked-by: Marek Vasut <marex@denx.de>
Tested-by: Marek Vasut <marex@denx.de>
2012-03-26 23:09:24 +02:00

82 lines
2.7 KiB
C

/*
* Freescale i.MX28 Register Accessors
*
* Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
* on behalf of DENX Software Engineering GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef __MX28_REGS_COMMON_H__
#define __MX28_REGS_COMMON_H__
/*
* The i.MX28 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 __mx28_reg_8(name) \
uint8_t name[4]; \
uint8_t name##_set[4]; \
uint8_t name##_clr[4]; \
uint8_t name##_tog[4]; \
#define __mx28_reg_32(name) \
uint32_t name; \
uint32_t name##_set; \
uint32_t name##_clr; \
uint32_t name##_tog;
struct mx28_register_8 {
__mx28_reg_8(reg)
};
struct mx28_register_32 {
__mx28_reg_32(reg)
};
#define mx28_reg_8(name) \
union { \
struct { __mx28_reg_8(name) }; \
struct mx28_register_32 name##_reg; \
};
#define mx28_reg_32(name) \
union { \
struct { __mx28_reg_32(name) }; \
struct mx28_register_32 name##_reg; \
};
#endif /* __MX28_REGS_COMMON_H__ */