This patch introduces support for the PIO mapping API on the ARM
architecture. It is currently only meant as an example for discussions
and it can be further optimised.
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
---
arch/arm/Kconfig | 3 ++
arch/arm/include/asm/pio-mapping.h | 52 ++++++++++++++++++++++++++++++++++++
2 files changed, 55 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/include/asm/pio-mapping.h
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 4c33ca8..e48adcf 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -161,6 +161,9 @@ config ARCH_MTD_XIP
config GENERIC_HARDIRQS_NO__DO_IRQ
def_bool y
+config HAVE_ARCH_PIO
+ def_bool y
+
if OPROFILE
config OPROFILE_ARMV6
diff --git a/arch/arm/include/asm/pio-mapping.h b/arch/arm/include/asm/pio-mapping.h
new file mode 100644
index 0000000..d7c866a
--- /dev/null
+++ b/arch/arm/include/asm/pio-mapping.h
@@ -0,0 +1,52 @@
+/*
+ * include/linux/pio-mapping.h
+ *
+ * Copyright (C) 2010 ARM Ltd.
+ * Written by Catalin Marinas <catalin.marinas@xxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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 ASM_PIO_MAPPING_H
+#define ASM_PIO_MAPPING_H
+
+#include <asm/cacheflush.h>
+
+static inline void *pio_map_single(void *addr, size_t size,
+ enum pio_data_direction dir)
+{
+ return addr;
+}
+
+static inline void pio_unmap_single(void *addr, size_t size,
+ enum pio_data_direction dir)
+{
+ if (dir == PIO_FROM_DEVICE)
+ __cpuc_flush_dcache_area(addr, size);
+}
+
+static inline void *pio_map_page(struct page *page, unsigned long offset,
+ size_t size, enum pio_data_direction dir)
+{
+ return page_address(page) + offset;
+}
+
+static inline void pio_unmap_page(void *addr, size_t size,
+ enum pio_data_direction dir)
+{
+ if (dir == PIO_FROM_DEVICE)
+ __cpuc_flush_dcache_area(addr, size);
+}
+
+#endif /* ASM_PIO_MAPPING_H */
--
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