mtd: physmap_of: add a hook for Intel IXP4xx flash probing (2aba2f2a) · Commits · 戴 / test

drivers/mtd/maps/Kconfig

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Original line number	Diff line number	Diff line
		@@ -96,6 +96,17 @@ config MTD_PHYSMAP_GEMINI
		platforms, some detection and setting up parallel mode on the
		external interface.

		config MTD_PHYSMAP_IXP4XX
		bool "Intel IXP4xx OF-based physical memory map handling"
		depends on MTD_PHYSMAP_OF
		depends on ARM
		select MTD_COMPLEX_MAPPINGS
		select MTD_CFI_BE_BYTE_SWAP if CPU_BIG_ENDIAN
		default ARCH_IXP4XX
		help
		This provides some extra DT physmap parsing for the Intel IXP4xx
		platforms, some elaborate endianness handling in particular.

		config MTD_PHYSMAP_GPIO_ADDR
		bool "GPIO-assisted Flash Chip Support"
		depends on MTD_PHYSMAP

drivers/mtd/maps/Makefile

+1 −0

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		@@ -20,6 +20,7 @@ obj-$(CONFIG_MTD_PXA2XX) += pxa2xx-flash.o
		physmap-objs-y += physmap-core.o
		physmap-objs-$(CONFIG_MTD_PHYSMAP_VERSATILE) += physmap-versatile.o
		physmap-objs-$(CONFIG_MTD_PHYSMAP_GEMINI) += physmap-gemini.o
		physmap-objs-$(CONFIG_MTD_PHYSMAP_IXP4XX) += physmap-ixp4xx.o
		physmap-objs := $(physmap-objs-y)
		obj-$(CONFIG_MTD_PHYSMAP) += physmap.o
		obj-$(CONFIG_MTD_PISMO) += pismo.o

drivers/mtd/maps/physmap-core.c

+5 −0

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		@@ -41,6 +41,7 @@
		#include <linux/gpio/consumer.h>

		#include "physmap-gemini.h"
		#include "physmap-ixp4xx.h"
		#include "physmap-versatile.h"

		struct physmap_flash_info {
		@@ -370,6 +371,10 @@ static int physmap_flash_of_init(struct platform_device *dev)
		if (err)
		return err;

		err = of_flash_probe_ixp4xx(dev, dp, &info->maps[i]);
		if (err)
		return err;

		err = of_flash_probe_versatile(dev, dp, &info->maps[i]);
		if (err)
		return err;

drivers/mtd/maps/physmap-ixp4xx.c

0 → 100644

+132 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* Intel IXP4xx OF physmap add-on
		* Copyright (C) 2019 Linus Walleij <linus.walleij@linaro.org>
		*
		* Based on the ixp4xx.c map driver, originally written by:
		* Intel Corporation
		* Deepak Saxena <dsaxena@mvista.com>
		* Copyright (C) 2002 Intel Corporation
		* Copyright (C) 2003-2004 MontaVista Software, Inc.
		*/
		#include <linux/export.h>
		#include <linux/of.h>
		#include <linux/of_device.h>
		#include <linux/mtd/map.h>
		#include <linux/mtd/xip.h>
		#include "physmap-ixp4xx.h"

		/*
		* Read/write a 16 bit word from flash address 'addr'.
		*
		* When the cpu is in little-endian mode it swizzles the address lines
		* ('address coherency') so we need to undo the swizzling to ensure commands
		* and the like end up on the correct flash address.
		*
		* To further complicate matters, due to the way the expansion bus controller
		* handles 32 bit reads, the byte stream ABCD is stored on the flash as:
		* D15 D0
		* +---+---+
		* \| A \| B \| 0
		* +---+---+
		* \| C \| D \| 2
		* +---+---+
		* This means that on LE systems each 16 bit word must be swapped. Note that
		* this requires CONFIG_MTD_CFI_BE_BYTE_SWAP to be enabled to 'unswap' the CFI
		* data and other flash commands which are always in D7-D0.
		*/
		#ifndef CONFIG_CPU_BIG_ENDIAN

		static inline u16 flash_read16(void __iomem *addr)
		{
		return be16_to_cpu(__raw_readw((void __iomem *)((unsigned long)addr ^ 0x2)));
		}

		static inline void flash_write16(u16 d, void __iomem *addr)
		{
		__raw_writew(cpu_to_be16(d), (void __iomem *)((unsigned long)addr ^ 0x2));
		}

		#define BYTE0(h) ((h) & 0xFF)
		#define BYTE1(h) (((h) >> 8) & 0xFF)

		#else

		static inline u16 flash_read16(const void __iomem *addr)
		{
		return __raw_readw(addr);
		}

		static inline void flash_write16(u16 d, void __iomem *addr)
		{
		__raw_writew(d, addr);
		}

		#define BYTE0(h) (((h) >> 8) & 0xFF)
		#define BYTE1(h) ((h) & 0xFF)
		#endif

		static map_word ixp4xx_read16(struct map_info *map, unsigned long ofs)
		{
		map_word val;

		val.x[0] = flash_read16(map->virt + ofs);
		return val;
		}

		/*
		* The IXP4xx expansion bus only allows 16-bit wide acceses
		* when attached to a 16-bit wide device (such as the 28F128J3A),
		* so we can't just memcpy_fromio().
		*/
		static void ixp4xx_copy_from(struct map_info map, void to,
		unsigned long from, ssize_t len)
		{
		u8 dest = (u8 ) to;
		void __iomem *src = map->virt + from;

		if (len <= 0)
		return;

		if (from & 1) {
		*dest++ = BYTE1(flash_read16(src-1));
		src++;
		--len;
		}

		while (len >= 2) {
		u16 data = flash_read16(src);
		*dest++ = BYTE0(data);
		*dest++ = BYTE1(data);
		src += 2;
		len -= 2;
		}

		if (len > 0)
		*dest++ = BYTE0(flash_read16(src));
		}

		static void ixp4xx_write16(struct map_info *map, map_word d, unsigned long adr)
		{
		flash_write16(d.x[0], map->virt + adr);
		}

		int of_flash_probe_ixp4xx(struct platform_device *pdev,
		struct device_node *np,
		struct map_info *map)
		{
		struct device *dev = &pdev->dev;

		/* Multiplatform guard */
		if (!of_device_is_compatible(np, "intel,ixp4xx-flash"))
		return 0;

		map->read = ixp4xx_read16;
		map->write = ixp4xx_write16;
		map->copy_from = ixp4xx_copy_from;
		map->copy_to = NULL;

		dev_info(dev, "initialized Intel IXP4xx-specific physmap control\n");

		return 0;
		}

drivers/mtd/maps/physmap-ixp4xx.h

0 → 100644

+17 −0

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		/* SPDX-License-Identifier: GPL-2.0 */
		#include <linux/of.h>
		#include <linux/mtd/map.h>

		#ifdef CONFIG_MTD_PHYSMAP_IXP4XX
		int of_flash_probe_ixp4xx(struct platform_device *pdev,
		struct device_node *np,
		struct map_info *map);
		#else
		static inline
		int of_flash_probe_ixp4xx(struct platform_device *pdev,
		struct device_node *np,
		struct map_info *map)
		{
		return 0;
		}
		#endif

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