drivers/mtd/maps/sc520cdp.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /* sc520cdp.c -- MTD map driver for AMD SC520 Customer Development Platform
  *
  * Copyright (C) 2001 Sysgo Real-Time Solutions GmbH
  *
  * The SC520CDP is an evaluation board for the Elan SC520 processor available
  * from AMD. It has two banks of 32-bit Flash ROM, each 8 Megabytes in size,
  * and up to 512 KiB of 8-bit DIL Flash ROM.
  * For details see https://www.amd.com/products/epd/desiging/evalboards/18.elansc520/520_cdp_brief/index.html
  */

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <asm/io.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/map.h>
 #include <linux/mtd/concat.h>

 /*
 ** The Embedded Systems BIOS decodes the first FLASH starting at
 ** 0x8400000. This is a *terrible* place for it because accessing
 ** the flash at this location causes the A22 address line to be high
 ** (that's what 0x8400000 binary's ought to be). But this is the highest
 ** order address line on the raw flash devices themselves!!
 ** This causes the top HALF of the flash to be accessed first. Beyond
 ** the physical limits of the flash, the flash chip aliases over (to
 ** 0x880000 which causes the bottom half to be accessed. This splits the
 ** flash into two and inverts it! If you then try to access this from another
 ** program that does NOT do this insanity, then you *will* access the
 ** first half of the flash, but not find what you expect there. That
 ** stuff is in the *second* half! Similarly, the address used by the
 ** BIOS for the second FLASH bank is also quite a bad choice.
 ** If REPROGRAM_PAR is defined below (the default), then this driver will
 ** choose more useful addresses for the FLASH banks by reprogramming the
 ** responsible PARxx registers in the SC520's MMCR region. This will
 ** cause the settings to be incompatible with the BIOS's settings, which
 ** shouldn't be a problem since you are running Linux, (i.e. the BIOS is
 ** not much use anyway). However, if you need to be compatible with
 ** the BIOS for some reason, just undefine REPROGRAM_PAR.
 */
 #define REPROGRAM_PAR


 #ifdef REPROGRAM_PAR

 /* These are the addresses we want.. */
 #define WINDOW_ADDR_0	0x08800000
 #define WINDOW_ADDR_1	0x09000000
 #define WINDOW_ADDR_2	0x09800000

 /* .. and these are the addresses the BIOS gives us */
 #define WINDOW_ADDR_0_BIOS	0x08400000
 #define WINDOW_ADDR_1_BIOS	0x08c00000
 #define WINDOW_ADDR_2_BIOS	0x09400000

 #else

 #define WINDOW_ADDR_0	0x08400000
 #define WINDOW_ADDR_1	0x08C00000
 #define WINDOW_ADDR_2	0x09400000

 #endif

 #define WINDOW_SIZE_0	0x00800000
 #define WINDOW_SIZE_1	0x00800000
 #define WINDOW_SIZE_2	0x00080000


 static struct map_info sc520cdp_map[] = {
 	{
 		.name = "SC520CDP Flash Bank #0",
 		.size = WINDOW_SIZE_0,
 		.bankwidth = 4,
 		.phys = WINDOW_ADDR_0
 	},
 	{
 		.name = "SC520CDP Flash Bank #1",
 		.size = WINDOW_SIZE_1,
 		.bankwidth = 4,
 		.phys = WINDOW_ADDR_1
 	},
 	{
 		.name = "SC520CDP DIL Flash",
 		.size = WINDOW_SIZE_2,
 		.bankwidth = 1,
 		.phys = WINDOW_ADDR_2
 	},
 };

 #define NUM_FLASH_BANKS	ARRAY_SIZE(sc520cdp_map)

 static struct mtd_info *mymtd[NUM_FLASH_BANKS];
 static struct mtd_info *merged_mtd;

 #ifdef REPROGRAM_PAR

 /*
 ** The SC520 MMCR (memory mapped control register) region resides
 ** at 0xFFFEF000. The 16 Programmable Address Region (PAR) registers
 ** are at offset 0x88 in the MMCR:
 */
 #define SC520_MMCR_BASE		0xFFFEF000
 #define SC520_MMCR_EXTENT	0x1000
 #define SC520_PAR(x)		((0x88/sizeof(unsigned long)) + (x))
 #define NUM_SC520_PAR		16	/* total number of PAR registers */

 /*
 ** The highest three bits in a PAR register determine what target
 ** device is controlled by this PAR. Here, only ROMCS? and BOOTCS
 ** devices are of interest.
 */
 #define SC520_PAR_BOOTCS	(0x4<<29)
 #define SC520_PAR_ROMCS0	(0x5<<29)
 #define SC520_PAR_ROMCS1	(0x6<<29)
 #define SC520_PAR_TRGDEV	(0x7<<29)

 /*
 ** Bits 28 thru 26 determine some attributes for the
 ** region controlled by the PAR. (We only use non-cacheable)
 */
 #define SC520_PAR_WRPROT	(1<<26)	/* write protected       */
 #define SC520_PAR_NOCACHE	(1<<27)	/* non-cacheable         */
 #define SC520_PAR_NOEXEC	(1<<28)	/* code execution denied */


 /*
 ** Bit 25 determines the granularity: 4K or 64K
 */
 #define SC520_PAR_PG_SIZ4	(0<<25)
 #define SC520_PAR_PG_SIZ64	(1<<25)

 /*
 ** Build a value to be written into a PAR register.
 ** We only need ROM entries, 64K page size:
 */
 #define SC520_PAR_ENTRY(trgdev, address, size) \
 	((trgdev) | SC520_PAR_NOCACHE | SC520_PAR_PG_SIZ64 | \
 	(address) >> 16 | (((size) >> 16) - 1) << 14)

 struct sc520_par_table
 {
 	unsigned long trgdev;
 	unsigned long new_par;
 	unsigned long default_address;
 };

 static const struct sc520_par_table par_table[NUM_FLASH_BANKS] =
 {
 	{	/* Flash Bank #0: selected by ROMCS0 */
 		SC520_PAR_ROMCS0,
 		SC520_PAR_ENTRY(SC520_PAR_ROMCS0, WINDOW_ADDR_0, WINDOW_SIZE_0),
 		WINDOW_ADDR_0_BIOS
 	},
 	{	/* Flash Bank #1: selected by ROMCS1 */
 		SC520_PAR_ROMCS1,
 		SC520_PAR_ENTRY(SC520_PAR_ROMCS1, WINDOW_ADDR_1, WINDOW_SIZE_1),
 		WINDOW_ADDR_1_BIOS
 	},
 	{	/* DIL (BIOS) Flash: selected by BOOTCS */
 		SC520_PAR_BOOTCS,
 		SC520_PAR_ENTRY(SC520_PAR_BOOTCS, WINDOW_ADDR_2, WINDOW_SIZE_2),
 		WINDOW_ADDR_2_BIOS
 	}
 };


 static void sc520cdp_setup_par(void)
 {
 	unsigned long __iomem *mmcr;
 	unsigned long mmcr_val;
 	int i, j;

 	/* map in SC520's MMCR area */
 	mmcr = ioremap(SC520_MMCR_BASE, SC520_MMCR_EXTENT);
 	if(!mmcr) { /* ioremap failed: skip the PAR reprogramming */
 		/* force physical address fields to BIOS defaults: */
 		for(i = 0; i < NUM_FLASH_BANKS; i++)
 			sc520cdp_map[i].phys = par_table[i].default_address;
 		return;
 	}

 	/*
 	** Find the PARxx registers that are responsible for activating
 	** ROMCS0, ROMCS1 and BOOTCS. Reprogram each of these with a
 	** new value from the table.
 	*/
 	for(i = 0; i < NUM_FLASH_BANKS; i++) {		/* for each par_table entry  */
 		for(j = 0; j < NUM_SC520_PAR; j++) {	/* for each PAR register     */
 			mmcr_val = readl(&mmcr[SC520_PAR(j)]);
 			/* if target device field matches, reprogram the PAR */
 			if((mmcr_val & SC520_PAR_TRGDEV) == par_table[i].trgdev)
 			{
 				writel(par_table[i].new_par, &mmcr[SC520_PAR(j)]);
 				break;
 			}
 		}
 		if(j == NUM_SC520_PAR)
 		{	/* no matching PAR found: try default BIOS address */
 			printk(KERN_NOTICE "Could not find PAR responsible for %s\n",
 				sc520cdp_map[i].name);
 			printk(KERN_NOTICE "Trying default address 0x%lx\n",
 				par_table[i].default_address);
 			sc520cdp_map[i].phys = par_table[i].default_address;
 		}
 	}
 	iounmap(mmcr);
 }
 #endif


 static int __init init_sc520cdp(void)
 {
 	int i, j, devices_found = 0;

 #ifdef REPROGRAM_PAR
 	/* reprogram PAR registers so flash appears at the desired addresses */
 	sc520cdp_setup_par();
 #endif

 	for (i = 0; i < NUM_FLASH_BANKS; i++) {
 		printk(KERN_NOTICE "SC520 CDP flash device: 0x%Lx at 0x%Lx\n",
 			(unsigned long long)sc520cdp_map[i].size,
 			(unsigned long long)sc520cdp_map[i].phys);

 		sc520cdp_map[i].virt = ioremap(sc520cdp_map[i].phys, sc520cdp_map[i].size);

 		if (!sc520cdp_map[i].virt) {
 			printk("Failed to ioremap\n");
 			for (j = 0; j < i; j++) {
 				if (mymtd[j]) {
 					map_destroy(mymtd[j]);
 					iounmap(sc520cdp_map[j].virt);
 				}
 			}
 			return -EIO;
 		}

 		simple_map_init(&sc520cdp_map[i]);

 		mymtd[i] = do_map_probe("cfi_probe", &sc520cdp_map[i]);
 		if(!mymtd[i])
 			mymtd[i] = do_map_probe("jedec_probe", &sc520cdp_map[i]);
 		if(!mymtd[i])
 			mymtd[i] = do_map_probe("map_rom", &sc520cdp_map[i]);

 		if (mymtd[i]) {
 			mymtd[i]->owner = THIS_MODULE;
 			++devices_found;
 		}
 		else {
 			iounmap(sc520cdp_map[i].virt);
 		}
 	}
 	if(devices_found >= 2) {
 		/* Combine the two flash banks into a single MTD device & register it: */
 		merged_mtd = mtd_concat_create(mymtd, 2, "SC520CDP Flash Banks #0 and #1");
 		if(merged_mtd)
 			mtd_device_register(merged_mtd, NULL, 0);
 	}
 	if(devices_found == 3) /* register the third (DIL-Flash) device */
 		mtd_device_register(mymtd[2], NULL, 0);
 	return(devices_found ? 0 : -ENXIO);
 }

 static void __exit cleanup_sc520cdp(void)
 {
 	int i;

 	if (merged_mtd) {
 		mtd_device_unregister(merged_mtd);
 		mtd_concat_destroy(merged_mtd);
 	}
 	if (mymtd[2])
 		mtd_device_unregister(mymtd[2]);

 	for (i = 0; i < NUM_FLASH_BANKS; i++) {
 		if (mymtd[i])
 			map_destroy(mymtd[i]);
 		if (sc520cdp_map[i].virt) {
 			iounmap(sc520cdp_map[i].virt);
 			sc520cdp_map[i].virt = NULL;
 		}
 	}
 }

 module_init(init_sc520cdp);
 module_exit(cleanup_sc520cdp);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Sysgo Real-Time Solutions GmbH");
 MODULE_DESCRIPTION("MTD map driver for AMD SC520 Customer Development Platform");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/* sc520cdp.c -- MTD map driver for AMD SC520 Customer Development Platform
	*
	* Copyright (C) 2001 Sysgo Real-Time Solutions GmbH
	*
	* The SC520CDP is an evaluation board for the Elan SC520 processor available
	* from AMD. It has two banks of 32-bit Flash ROM, each 8 Megabytes in size,
	* and up to 512 KiB of 8-bit DIL Flash ROM.
	* For details see https://www.amd.com/products/epd/desiging/evalboards/18.elansc520/520_cdp_brief/index.html
	*/

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <asm/io.h>
	#include <linux/mtd/mtd.h>
	#include <linux/mtd/map.h>
	#include <linux/mtd/concat.h>

	/*
	** The Embedded Systems BIOS decodes the first FLASH starting at
	** 0x8400000. This is a terrible place for it because accessing
	** the flash at this location causes the A22 address line to be high
	** (that's what 0x8400000 binary's ought to be). But this is the highest
	** order address line on the raw flash devices themselves!!
	** This causes the top HALF of the flash to be accessed first. Beyond
	** the physical limits of the flash, the flash chip aliases over (to
	** 0x880000 which causes the bottom half to be accessed. This splits the
	** flash into two and inverts it! If you then try to access this from another
	** program that does NOT do this insanity, then you will access the
	** first half of the flash, but not find what you expect there. That
	** stuff is in the second half! Similarly, the address used by the
	** BIOS for the second FLASH bank is also quite a bad choice.
	** If REPROGRAM_PAR is defined below (the default), then this driver will
	** choose more useful addresses for the FLASH banks by reprogramming the
	** responsible PARxx registers in the SC520's MMCR region. This will
	** cause the settings to be incompatible with the BIOS's settings, which
	** shouldn't be a problem since you are running Linux, (i.e. the BIOS is
	** not much use anyway). However, if you need to be compatible with
	** the BIOS for some reason, just undefine REPROGRAM_PAR.
	*/
	#define REPROGRAM_PAR



	#ifdef REPROGRAM_PAR

	/* These are the addresses we want.. */
	#define WINDOW_ADDR_0 0x08800000
	#define WINDOW_ADDR_1 0x09000000
	#define WINDOW_ADDR_2 0x09800000

	/* .. and these are the addresses the BIOS gives us */
	#define WINDOW_ADDR_0_BIOS 0x08400000
	#define WINDOW_ADDR_1_BIOS 0x08c00000
	#define WINDOW_ADDR_2_BIOS 0x09400000

	#else

	#define WINDOW_ADDR_0 0x08400000
	#define WINDOW_ADDR_1 0x08C00000
	#define WINDOW_ADDR_2 0x09400000

	#endif

	#define WINDOW_SIZE_0 0x00800000
	#define WINDOW_SIZE_1 0x00800000
	#define WINDOW_SIZE_2 0x00080000


	static struct map_info sc520cdp_map[] = {
	{
	.name = "SC520CDP Flash Bank #0",
	.size = WINDOW_SIZE_0,
	.bankwidth = 4,
	.phys = WINDOW_ADDR_0
	},
	{
	.name = "SC520CDP Flash Bank #1",
	.size = WINDOW_SIZE_1,
	.bankwidth = 4,
	.phys = WINDOW_ADDR_1
	},
	{
	.name = "SC520CDP DIL Flash",
	.size = WINDOW_SIZE_2,
	.bankwidth = 1,
	.phys = WINDOW_ADDR_2
	},
	};

	#define NUM_FLASH_BANKS ARRAY_SIZE(sc520cdp_map)

	static struct mtd_info *mymtd[NUM_FLASH_BANKS];
	static struct mtd_info *merged_mtd;

	#ifdef REPROGRAM_PAR

	/*
	** The SC520 MMCR (memory mapped control register) region resides
	** at 0xFFFEF000. The 16 Programmable Address Region (PAR) registers
	** are at offset 0x88 in the MMCR:
	*/
	#define SC520_MMCR_BASE 0xFFFEF000
	#define SC520_MMCR_EXTENT 0x1000
	#define SC520_PAR(x) ((0x88/sizeof(unsigned long)) + (x))
	#define NUM_SC520_PAR 16 /* total number of PAR registers */

	/*
	** The highest three bits in a PAR register determine what target
	** device is controlled by this PAR. Here, only ROMCS? and BOOTCS
	** devices are of interest.
	*/
	#define SC520_PAR_BOOTCS (0x4<<29)
	#define SC520_PAR_ROMCS0 (0x5<<29)
	#define SC520_PAR_ROMCS1 (0x6<<29)
	#define SC520_PAR_TRGDEV (0x7<<29)

	/*
	** Bits 28 thru 26 determine some attributes for the
	** region controlled by the PAR. (We only use non-cacheable)
	*/
	#define SC520_PAR_WRPROT (1<<26) /* write protected */
	#define SC520_PAR_NOCACHE (1<<27) /* non-cacheable */
	#define SC520_PAR_NOEXEC (1<<28) /* code execution denied */


	/*
	** Bit 25 determines the granularity: 4K or 64K
	*/
	#define SC520_PAR_PG_SIZ4 (0<<25)
	#define SC520_PAR_PG_SIZ64 (1<<25)

	/*
	** Build a value to be written into a PAR register.
	** We only need ROM entries, 64K page size:
	*/
	#define SC520_PAR_ENTRY(trgdev, address, size) \
	((trgdev) \| SC520_PAR_NOCACHE \| SC520_PAR_PG_SIZ64 \| \
	(address) >> 16 \| (((size) >> 16) - 1) << 14)

	struct sc520_par_table
	{
	unsigned long trgdev;
	unsigned long new_par;
	unsigned long default_address;
	};

	static const struct sc520_par_table par_table[NUM_FLASH_BANKS] =
	{
	{ /* Flash Bank #0: selected by ROMCS0 */
	SC520_PAR_ROMCS0,
	SC520_PAR_ENTRY(SC520_PAR_ROMCS0, WINDOW_ADDR_0, WINDOW_SIZE_0),
	WINDOW_ADDR_0_BIOS
	},
	{ /* Flash Bank #1: selected by ROMCS1 */
	SC520_PAR_ROMCS1,
	SC520_PAR_ENTRY(SC520_PAR_ROMCS1, WINDOW_ADDR_1, WINDOW_SIZE_1),
	WINDOW_ADDR_1_BIOS
	},
	{ /* DIL (BIOS) Flash: selected by BOOTCS */
	SC520_PAR_BOOTCS,
	SC520_PAR_ENTRY(SC520_PAR_BOOTCS, WINDOW_ADDR_2, WINDOW_SIZE_2),
	WINDOW_ADDR_2_BIOS
	}
	};


	static void sc520cdp_setup_par(void)
	{
	unsigned long __iomem *mmcr;
	unsigned long mmcr_val;
	int i, j;

	/* map in SC520's MMCR area */
	mmcr = ioremap(SC520_MMCR_BASE, SC520_MMCR_EXTENT);
	if(!mmcr) { /* ioremap failed: skip the PAR reprogramming */
	/* force physical address fields to BIOS defaults: */
	for(i = 0; i < NUM_FLASH_BANKS; i++)
	sc520cdp_map[i].phys = par_table[i].default_address;
	return;
	}

	/*
	** Find the PARxx registers that are responsible for activating
	** ROMCS0, ROMCS1 and BOOTCS. Reprogram each of these with a
	** new value from the table.
	*/
	for(i = 0; i < NUM_FLASH_BANKS; i++) { /* for each par_table entry */
	for(j = 0; j < NUM_SC520_PAR; j++) { /* for each PAR register */
	mmcr_val = readl(&mmcr[SC520_PAR(j)]);
	/* if target device field matches, reprogram the PAR */
	if((mmcr_val & SC520_PAR_TRGDEV) == par_table[i].trgdev)
	{
	writel(par_table[i].new_par, &mmcr[SC520_PAR(j)]);
	break;
	}
	}
	if(j == NUM_SC520_PAR)
	{ /* no matching PAR found: try default BIOS address */
	printk(KERN_NOTICE "Could not find PAR responsible for %s\n",
	sc520cdp_map[i].name);
	printk(KERN_NOTICE "Trying default address 0x%lx\n",
	par_table[i].default_address);
	sc520cdp_map[i].phys = par_table[i].default_address;
	}
	}
	iounmap(mmcr);
	}
	#endif


	static int __init init_sc520cdp(void)
	{
	int i, j, devices_found = 0;

	#ifdef REPROGRAM_PAR
	/* reprogram PAR registers so flash appears at the desired addresses */
	sc520cdp_setup_par();
	#endif

	for (i = 0; i < NUM_FLASH_BANKS; i++) {
	printk(KERN_NOTICE "SC520 CDP flash device: 0x%Lx at 0x%Lx\n",
	(unsigned long long)sc520cdp_map[i].size,
	(unsigned long long)sc520cdp_map[i].phys);

	sc520cdp_map[i].virt = ioremap(sc520cdp_map[i].phys, sc520cdp_map[i].size);

	if (!sc520cdp_map[i].virt) {
	printk("Failed to ioremap\n");
	for (j = 0; j < i; j++) {
	if (mymtd[j]) {
	map_destroy(mymtd[j]);
	iounmap(sc520cdp_map[j].virt);
	}
	}
	return -EIO;
	}

	simple_map_init(&sc520cdp_map[i]);

	mymtd[i] = do_map_probe("cfi_probe", &sc520cdp_map[i]);
	if(!mymtd[i])
	mymtd[i] = do_map_probe("jedec_probe", &sc520cdp_map[i]);
	if(!mymtd[i])
	mymtd[i] = do_map_probe("map_rom", &sc520cdp_map[i]);

	if (mymtd[i]) {
	mymtd[i]->owner = THIS_MODULE;
	++devices_found;
	}
	else {
	iounmap(sc520cdp_map[i].virt);
	}
	}
	if(devices_found >= 2) {
	/* Combine the two flash banks into a single MTD device & register it: */
	merged_mtd = mtd_concat_create(mymtd, 2, "SC520CDP Flash Banks #0 and #1");
	if(merged_mtd)
	mtd_device_register(merged_mtd, NULL, 0);
	}
	if(devices_found == 3) /* register the third (DIL-Flash) device */
	mtd_device_register(mymtd[2], NULL, 0);
	return(devices_found ? 0 : -ENXIO);
	}

	static void __exit cleanup_sc520cdp(void)
	{
	int i;

	if (merged_mtd) {
	mtd_device_unregister(merged_mtd);
	mtd_concat_destroy(merged_mtd);
	}
	if (mymtd[2])
	mtd_device_unregister(mymtd[2]);

	for (i = 0; i < NUM_FLASH_BANKS; i++) {
	if (mymtd[i])
	map_destroy(mymtd[i]);
	if (sc520cdp_map[i].virt) {
	iounmap(sc520cdp_map[i].virt);
	sc520cdp_map[i].virt = NULL;
	}
	}
	}

	module_init(init_sc520cdp);
	module_exit(cleanup_sc520cdp);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Sysgo Real-Time Solutions GmbH");
	MODULE_DESCRIPTION("MTD map driver for AMD SC520 Customer Development Platform");