summaryrefslogtreecommitdiff
path: root/arch/arm/include/asm/imx-common/regs-common.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/include/asm/imx-common/regs-common.h')
-rw-r--r--arch/arm/include/asm/imx-common/regs-common.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/arch/arm/include/asm/imx-common/regs-common.h b/arch/arm/include/asm/imx-common/regs-common.h
new file mode 100644
index 0000000000..bcea419f99
--- /dev/null
+++ b/arch/arm/include/asm/imx-common/regs-common.h
@@ -0,0 +1,82 @@
+/*
+ * Freescale i.MXS 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 __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) \
+ union { \
+ 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__ */