Date:   Tue, 24 Jan 2017 15:05:21 +0800
From:   "zhichang.yuan" <yuanzhichang@...ilicon.com>
To:     <catalin.marinas@....com>, <will.deacon@....com>,
        <robh+dt@...nel.org>, <frowand.list@...il.com>,
        <bhelgaas@...gle.com>, <rafael@...nel.org>, <mark.rutland@....com>,
        <brian.starkey@....com>, <olof@...om.net>, <arnd@...db.de>,
        <linux-arm-kernel@...ts.infradead.org>
CC:     <lorenzo.pieralisi@....com>, <benh@...nel.crashing.org>,
        <linux-kernel@...r.kernel.org>, <linuxarm@...wei.com>,
        <devicetree@...r.kernel.org>, <linux-pci@...r.kernel.org>,
        <linux-serial@...r.kernel.org>, <minyard@....org>,
        <liviu.dudau@....com>, <zourongrong@...il.com>,
        <john.garry@...wei.com>, <gabriele.paoloni@...wei.com>,
        <zhichang.yuan02@...il.com>, <kantyzc@....com>,
        <xuwei5@...ilicon.com>,
        "zhichang.yuan" <yuanzhichang@...ilicon.com>
Subject: [PATCH V6 1/5] LIB: Indirect ISA/LPC port IO introduced

Low-pin-count interface is integrated into some SoCs. The accesses to those
peripherals under LPC make use of I/O ports rather than the memory mapped I/O.

To drive these devices, this patch introduces a method named indirect-IO.
In this method the in/out() accessor in include/asm-generic/io.h will be
redefined. When upper layer drivers call in/out() with those known legacy port
addresses to access the peripherals, the I/O operations will be routed to the
right hooks which are registered specific to the host device, such as LPC.
Then the hardware relevant manupulations are finished by the corresponding
host.

According to the comments on V5, this patch adds a common indirect-IO driver
which support this I/O indirection to the generic directory.

In the later pathches, some host-relevant drivers are implemented to support
the specific I/O hooks and register them.
Based on these, the upper layer drivers which depend on in/out() can work well
without any extra work or any changes.

Signed-off-by: zhichang.yuan <yuanzhichang@...ilicon.com>
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@...wei.com>
Signed-off-by: John Garry <john.garry@...wei.com>
---
 include/asm-generic/io.h |  50 ++++++++++++++++
 include/linux/extio.h    |  85 +++++++++++++++++++++++++++
 include/linux/io.h       |   1 +
 lib/Kconfig              |   8 +++
 lib/Makefile             |   2 +
 lib/extio.c              | 147 +++++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 293 insertions(+)
 create mode 100644 include/linux/extio.h
 create mode 100644 lib/extio.c

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 7ef015e..c0d6db1 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -21,6 +21,8 @@
 
 #include <asm-generic/pci_iomap.h>
 
+#include <linux/extio.h>
+
 #ifndef mmiowb
 #define mmiowb() do {} while (0)
 #endif
@@ -358,51 +360,75 @@ static inline void writesq(volatile void __iomem *addr, const void *buffer,
  */
 
 #ifndef inb
+#ifdef CONFIG_INDIRECT_PIO
+#define inb extio_inb
+#else
 #define inb inb
 static inline u8 inb(unsigned long addr)
 {
 	return readb(PCI_IOBASE + addr);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef inw
+#ifdef CONFIG_INDIRECT_PIO
+#define inw extio_inw
+#else
 #define inw inw
 static inline u16 inw(unsigned long addr)
 {
 	return readw(PCI_IOBASE + addr);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef inl
+#ifdef CONFIG_INDIRECT_PIO
+#define inl extio_inl
+#else
 #define inl inl
 static inline u32 inl(unsigned long addr)
 {
 	return readl(PCI_IOBASE + addr);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef outb
+#ifdef CONFIG_INDIRECT_PIO
+#define outb extio_outb
+#else
 #define outb outb
 static inline void outb(u8 value, unsigned long addr)
 {
 	writeb(value, PCI_IOBASE + addr);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef outw
+#ifdef CONFIG_INDIRECT_PIO
+#define outw extio_outw
+#else
 #define outw outw
 static inline void outw(u16 value, unsigned long addr)
 {
 	writew(value, PCI_IOBASE + addr);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef outl
+#ifdef CONFIG_INDIRECT_PIO
+#define outl extio_outl
+#else
 #define outl outl
 static inline void outl(u32 value, unsigned long addr)
 {
 	writel(value, PCI_IOBASE + addr);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef inb_p
@@ -459,54 +485,78 @@ static inline void outl_p(u32 value, unsigned long addr)
  */
 
 #ifndef insb
+#ifdef CONFIG_INDIRECT_PIO
+#define insb extio_insb
+#else
 #define insb insb
 static inline void insb(unsigned long addr, void *buffer, unsigned int count)
 {
 	readsb(PCI_IOBASE + addr, buffer, count);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef insw
+#ifdef CONFIG_INDIRECT_PIO
+#define insw extio_insw
+#else
 #define insw insw
 static inline void insw(unsigned long addr, void *buffer, unsigned int count)
 {
 	readsw(PCI_IOBASE + addr, buffer, count);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef insl
+#ifdef CONFIG_INDIRECT_PIO
+#define insl extio_insl
+#else
 #define insl insl
 static inline void insl(unsigned long addr, void *buffer, unsigned int count)
 {
 	readsl(PCI_IOBASE + addr, buffer, count);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef outsb
+#ifdef CONFIG_INDIRECT_PIO
+#define outsb extio_outsb
+#else
 #define outsb outsb
 static inline void outsb(unsigned long addr, const void *buffer,
 			 unsigned int count)
 {
 	writesb(PCI_IOBASE + addr, buffer, count);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef outsw
+#ifdef CONFIG_INDIRECT_PIO
+#define outsw extio_outsw
+#else
 #define outsw outsw
 static inline void outsw(unsigned long addr, const void *buffer,
 			 unsigned int count)
 {
 	writesw(PCI_IOBASE + addr, buffer, count);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef outsl
+#ifdef CONFIG_INDIRECT_PIO
+#define outsl extio_outsl
+#else
 #define outsl outsl
 static inline void outsl(unsigned long addr, const void *buffer,
 			 unsigned int count)
 {
 	writesl(PCI_IOBASE + addr, buffer, count);
 }
+#endif /* CONFIG_INDIRECT_PIO */
 #endif
 
 #ifndef insb_p
diff --git a/include/linux/extio.h b/include/linux/extio.h
new file mode 100644
index 0000000..2ca7eab
--- /dev/null
+++ b/include/linux/extio.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2016 Hisilicon Limited, All Rights Reserved.
+ * Author: Zhichang Yuan <yuanzhichang@...ilicon.com>
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __LINUX_EXTIO_H
+#define __LINUX_EXTIO_H
+
+#ifdef __KERNEL__
+
+#include <linux/fwnode.h>
+
+struct extio_ops {
+	u64 (*pfin)(void *devobj, unsigned long ptaddr,	size_t dlen);
+	void (*pfout)(void *devobj, unsigned long ptaddr, u32 outval,
+					size_t dlen);
+	u64 (*pfins)(void *devobj, unsigned long ptaddr, void *inbuf,
+				size_t dlen, unsigned int count);
+	void (*pfouts)(void *devobj, unsigned long ptaddr,
+				const void *outbuf, size_t dlen,
+				unsigned int count);
+};
+
+struct extio_node {
+	unsigned long bus_start;	/* bus start address */
+	unsigned long io_start;	/* io port token corresponding to bus_start */
+	size_t range_size;	/* size of the extio node operating range */
+	struct fwnode_handle *fwnode;
+	struct list_head list;
+	struct extio_ops *ops;	/* ops operating on this node */
+	void *devpara;	/* private parameter of the host device */
+};
+
+extern u8 extio_inb(unsigned long addr);
+extern void extio_outb(u8 value, unsigned long addr);
+extern void extio_outw(u16 value, unsigned long addr);
+extern void extio_outl(u32 value, unsigned long addr);
+extern u16 extio_inw(unsigned long addr);
+extern u32 extio_inl(unsigned long addr);
+extern void extio_outb(u8 value, unsigned long addr);
+extern void extio_outw(u16 value, unsigned long addr);
+extern void extio_outl(u32 value, unsigned long addr);
+extern void extio_insb(unsigned long addr, void *buffer, unsigned int count);
+extern void extio_insl(unsigned long addr, void *buffer, unsigned int count);
+extern void extio_insw(unsigned long addr, void *buffer, unsigned int count);
+extern void extio_outsb(unsigned long addr, const void *buffer,
+			unsigned int count);
+extern void extio_outsw(unsigned long addr, const void *buffer,
+			unsigned int count);
+extern void extio_outsl(unsigned long addr, const void *buffer,
+			unsigned int count);
+
+#ifdef CONFIG_INDIRECT_PIO
+extern struct extio_node *extio_find_node(struct fwnode_handle *node);
+
+extern unsigned long
+extio_translate(struct fwnode_handle *node, unsigned long bus_addr);
+#else
+static inline struct extio_node *extio_find_node(struct fwnode_handle *node)
+{
+	return NULL;
+}
+
+static inline unsigned long
+extio_translate(struct fwnode_handle *node, unsigned long bus_addr)
+{
+	return -1;
+}
+#endif
+extern void register_extio(struct extio_node *node);
+
+#endif /* __KERNEL__ */
+#endif /* __LINUX_EXTIO_H */
diff --git a/include/linux/io.h b/include/linux/io.h
index 82ef36e..6c68478 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -24,6 +24,7 @@
 #include <linux/err.h>
 #include <asm/io.h>
 #include <asm/page.h>
+#include <linux/extio.h>
 
 struct device;
 struct resource;
diff --git a/lib/Kconfig b/lib/Kconfig
index 260a80e..1d27c44 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -59,6 +59,14 @@ config ARCH_USE_CMPXCHG_LOCKREF
 config ARCH_HAS_FAST_MULTIPLIER
 	bool
 
+config INDIRECT_PIO
+	bool "access peripherals with legacy I/O port"
+	depends on PCI
+	help
+	  Support special accessors for ISA I/O devices. This is needed for
+	  SoCs that have not I/O space and do not support standard MMIO
+	  read/write for the ISA range.
+
 config CRC_CCITT
 	tristate "CRC-CCITT functions"
 	help
diff --git a/lib/Makefile b/lib/Makefile
index bc4073a..bf03e05 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -70,6 +70,8 @@ obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o
 obj-$(CONFIG_CHECK_SIGNATURE) += check_signature.o
 obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
 
+obj-$(CONFIG_INDIRECT_PIO)	+= extio.o
+
 obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o
 
 obj-$(CONFIG_BTREE) += btree.o
diff --git a/lib/extio.c b/lib/extio.c
new file mode 100644
index 0000000..46228de
--- /dev/null
+++ b/lib/extio.c
@@ -0,0 +1,147 @@
+/*
+ * Copyright (C) 2016 Hisilicon Limited, All Rights Reserved.
+ * Author: Zhichang Yuan <yuanzhichang@...ilicon.com>
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/io.h>
+#include <linux/spinlock.h>
+
+static LIST_HEAD(extio_dev_list);
+static DEFINE_RWLOCK(extio_list_lock);
+
+void register_extio(struct extio_node *node)
+{
+	write_lock(&extio_list_lock);
+	list_add_tail(&node->list, &extio_dev_list);
+	write_unlock(&extio_list_lock);
+}
+
+static struct extio_node *find_extio_token(unsigned long addr)
+{
+	struct extio_node *extio_entry;
+
+	read_lock(&extio_list_lock);
+	list_for_each_entry(extio_entry, &extio_dev_list, list) {
+		if ((addr < extio_entry->io_start + extio_entry->range_size) &&
+			(addr >= extio_entry->io_start))
+			break;
+	}
+	read_unlock(&extio_list_lock);
+	return (&extio_entry->list == &extio_dev_list) ? NULL : extio_entry;
+}
+
+struct extio_node *extio_find_node(struct fwnode_handle *node)
+{
+	struct extio_node *entry;
+
+	read_lock(&extio_list_lock);
+	list_for_each_entry(entry, &extio_dev_list, list) {
+		if (entry->fwnode == node)
+			break;
+	}
+	read_unlock(&extio_list_lock);
+
+	return (&entry->list == &extio_dev_list) ? NULL : entry;
+}
+
+unsigned long extio_translate(struct fwnode_handle *node,
+		unsigned long bus_addr)
+{
+	struct extio_node *entry;
+	unsigned long port_id = -1;
+
+	read_lock(&extio_list_lock);
+	list_for_each_entry(entry, &extio_dev_list, list) {
+		if (entry->fwnode == node &&
+			bus_addr >= entry->bus_start &&
+			bus_addr - entry->bus_start < entry->range_size)
+			port_id = entry->io_start + bus_addr -
+					entry->bus_start;
+	}
+	read_unlock(&extio_list_lock);
+
+	return port_id;
+}
+
+#ifdef PCI_IOBASE
+
+#define BUILD_EXTIO(bw, type)						\
+type extio_in##bw(unsigned long addr)					\
+{									\
+	struct extio_node *extio_entry = find_extio_token(addr);	\
+									\
+	if (!extio_entry)						\
+		return read##bw(PCI_IOBASE + addr);			\
+	return extio_entry->ops->pfin ?					\
+			extio_entry->ops->pfin(extio_entry->devpara,	\
+			addr, sizeof(type)) : -1;			\
+}									\
+									\
+void extio_out##bw(type value, unsigned long addr)			\
+{									\
+	struct extio_node *extio_entry = find_extio_token(addr);	\
+									\
+	if (!extio_entry)						\
+		write##bw(value, PCI_IOBASE + addr);			\
+	else if (extio_entry->ops->pfout)				\
+		extio_entry->ops->pfout(extio_entry->devpara,		\
+				addr, value, sizeof(type));		\
+}									\
+									\
+void extio_ins##bw(unsigned long addr, void *buffer, unsigned int count)\
+{									\
+	struct extio_node *extio_entry = find_extio_token(addr);	\
+									\
+	if (!extio_entry)						\
+		reads##bw(PCI_IOBASE + addr, buffer, count);		\
+	else if (extio_entry->ops->pfins)				\
+		extio_entry->ops->pfins(extio_entry->devpara,		\
+				addr, buffer, sizeof(type), count);	\
+}									\
+									\
+void extio_outs##bw(unsigned long addr, const void *buffer,		\
+		    unsigned int count)					\
+{									\
+	struct extio_node *extio_entry = find_extio_token(addr);	\
+									\
+	if (!extio_entry)						\
+		writes##bw(PCI_IOBASE + addr, buffer, count);		\
+	else if (extio_entry->ops->pfouts)				\
+		extio_entry->ops->pfouts(extio_entry->devpara,		\
+				addr, buffer, sizeof(type), count);	\
+}
+
+BUILD_EXTIO(b, u8)
+
+EXPORT_SYMBOL(extio_inb);
+EXPORT_SYMBOL(extio_outb);
+EXPORT_SYMBOL(extio_insb);
+EXPORT_SYMBOL(extio_outsb);
+
+BUILD_EXTIO(w, u16)
+
+EXPORT_SYMBOL(extio_inw);
+EXPORT_SYMBOL(extio_outw);
+EXPORT_SYMBOL(extio_insw);
+EXPORT_SYMBOL(extio_outsw);
+
+BUILD_EXTIO(l, u32)
+
+EXPORT_SYMBOL(extio_inl);
+EXPORT_SYMBOL(extio_outl);
+EXPORT_SYMBOL(extio_insl);
+EXPORT_SYMBOL(extio_outsl);
+
+#endif /* PCI_IOBASE */
-- 
1.9.1

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