1 files changed, 444 insertions, 0 deletions
diff --git a/drivers/mtd/chips/cfi_util.c b/drivers/mtd/chips/cfi_util.c
new file mode 100644
index 000000000..140c69a67
--- /dev/null
+++ b/drivers/mtd/chips/cfi_util.c
@@ -0,0 +1,444 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common Flash Interface support:
+ *   Generic utility functions not dependent on command set
+ *
+ * Copyright (C) 2002 Red Hat
+ * Copyright (C) 2003 STMicroelectronics Limited
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <asm/io.h>
+#include <asm/byteorder.h>
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/mtd/xip.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/cfi.h>
+
+void cfi_udelay(int us)
+{
+	if (us >= 1000) {
+		msleep(DIV_ROUND_UP(us, 1000));
+	} else {
+		udelay(us);
+		cond_resched();
+	}
+}
+EXPORT_SYMBOL(cfi_udelay);
+
+/*
+ * Returns the command address according to the given geometry.
+ */
+uint32_t cfi_build_cmd_addr(uint32_t cmd_ofs,
+				struct map_info *map, struct cfi_private *cfi)
+{
+	unsigned bankwidth = map_bankwidth(map);
+	unsigned interleave = cfi_interleave(cfi);
+	unsigned type = cfi->device_type;
+	uint32_t addr;
+
+	addr = (cmd_ofs * type) * interleave;
+
+	/* Modify the unlock address if we are in compatibility mode.
+	 * For 16bit devices on 8 bit busses
+	 * and 32bit devices on 16 bit busses
+	 * set the low bit of the alternating bit sequence of the address.
+	 */
+	if (((type * interleave) > bankwidth) && ((cmd_ofs & 0xff) == 0xaa))
+		addr |= (type >> 1)*interleave;
+
+	return  addr;
+}
+EXPORT_SYMBOL(cfi_build_cmd_addr);
+
+/*
+ * Transforms the CFI command for the given geometry (bus width & interleave).
+ * It looks too long to be inline, but in the common case it should almost all
+ * get optimised away.
+ */
+map_word cfi_build_cmd(u_long cmd, struct map_info *map, struct cfi_private *cfi)
+{
+	map_word val = { {0} };
+	int wordwidth, words_per_bus, chip_mode, chips_per_word;
+	unsigned long onecmd;
+	int i;
+
+	/* We do it this way to give the compiler a fighting chance
+	   of optimising away all the crap for 'bankwidth' larger than
+	   an unsigned long, in the common case where that support is
+	   disabled */
+	if (map_bankwidth_is_large(map)) {
+		wordwidth = sizeof(unsigned long);
+		words_per_bus = (map_bankwidth(map)) / wordwidth; // i.e. normally 1
+	} else {
+		wordwidth = map_bankwidth(map);
+		words_per_bus = 1;
+	}
+
+	chip_mode = map_bankwidth(map) / cfi_interleave(cfi);
+	chips_per_word = wordwidth * cfi_interleave(cfi) / map_bankwidth(map);
+
+	/* First, determine what the bit-pattern should be for a single
+	   device, according to chip mode and endianness... */
+	switch (chip_mode) {
+	default: BUG();
+	case 1:
+		onecmd = cmd;
+		break;
+	case 2:
+		onecmd = cpu_to_cfi16(map, cmd);
+		break;
+	case 4:
+		onecmd = cpu_to_cfi32(map, cmd);
+		break;
+	}
+
+	/* Now replicate it across the size of an unsigned long, or
+	   just to the bus width as appropriate */
+	switch (chips_per_word) {
+	default: BUG();
+#if BITS_PER_LONG >= 64
+	case 8:
+		onecmd |= (onecmd << (chip_mode * 32));
+		fallthrough;
+#endif
+	case 4:
+		onecmd |= (onecmd << (chip_mode * 16));
+		fallthrough;
+	case 2:
+		onecmd |= (onecmd << (chip_mode * 8));
+		fallthrough;
+	case 1:
+		;
+	}
+
+	/* And finally, for the multi-word case, replicate it
+	   in all words in the structure */
+	for (i=0; i < words_per_bus; i++) {
+		val.x[i] = onecmd;
+	}
+
+	return val;
+}
+EXPORT_SYMBOL(cfi_build_cmd);
+
+unsigned long cfi_merge_status(map_word val, struct map_info *map,
+					   struct cfi_private *cfi)
+{
+	int wordwidth, words_per_bus, chip_mode, chips_per_word;
+	unsigned long onestat, res = 0;
+	int i;
+
+	/* We do it this way to give the compiler a fighting chance
+	   of optimising away all the crap for 'bankwidth' larger than
+	   an unsigned long, in the common case where that support is
+	   disabled */
+	if (map_bankwidth_is_large(map)) {
+		wordwidth = sizeof(unsigned long);
+		words_per_bus = (map_bankwidth(map)) / wordwidth; // i.e. normally 1
+	} else {
+		wordwidth = map_bankwidth(map);
+		words_per_bus = 1;
+	}
+
+	chip_mode = map_bankwidth(map) / cfi_interleave(cfi);
+	chips_per_word = wordwidth * cfi_interleave(cfi) / map_bankwidth(map);
+
+	onestat = val.x[0];
+	/* Or all status words together */
+	for (i=1; i < words_per_bus; i++) {
+		onestat |= val.x[i];
+	}
+
+	res = onestat;
+	switch(chips_per_word) {
+	default: BUG();
+#if BITS_PER_LONG >= 64
+	case 8:
+		res |= (onestat >> (chip_mode * 32));
+		fallthrough;
+#endif
+	case 4:
+		res |= (onestat >> (chip_mode * 16));
+		fallthrough;
+	case 2:
+		res |= (onestat >> (chip_mode * 8));
+		fallthrough;
+	case 1:
+		;
+	}
+
+	/* Last, determine what the bit-pattern should be for a single
+	   device, according to chip mode and endianness... */
+	switch (chip_mode) {
+	case 1:
+		break;
+	case 2:
+		res = cfi16_to_cpu(map, res);
+		break;
+	case 4:
+		res = cfi32_to_cpu(map, res);
+		break;
+	default: BUG();
+	}
+	return res;
+}
+EXPORT_SYMBOL(cfi_merge_status);
+
+/*
+ * Sends a CFI command to a bank of flash for the given geometry.
+ *
+ * Returns the offset in flash where the command was written.
+ * If prev_val is non-null, it will be set to the value at the command address,
+ * before the command was written.
+ */
+uint32_t cfi_send_gen_cmd(u_char cmd, uint32_t cmd_addr, uint32_t base,
+				struct map_info *map, struct cfi_private *cfi,
+				int type, map_word *prev_val)
+{
+	map_word val;
+	uint32_t addr = base + cfi_build_cmd_addr(cmd_addr, map, cfi);
+	val = cfi_build_cmd(cmd, map, cfi);
+
+	if (prev_val)
+		*prev_val = map_read(map, addr);
+
+	map_write(map, val, addr);
+
+	return addr - base;
+}
+EXPORT_SYMBOL(cfi_send_gen_cmd);
+
+int __xipram cfi_qry_present(struct map_info *map, __u32 base,
+			     struct cfi_private *cfi)
+{
+	int osf = cfi->interleave * cfi->device_type;	/* scale factor */
+	map_word val[3];
+	map_word qry[3];
+
+	qry[0] = cfi_build_cmd('Q', map, cfi);
+	qry[1] = cfi_build_cmd('R', map, cfi);
+	qry[2] = cfi_build_cmd('Y', map, cfi);
+
+	val[0] = map_read(map, base + osf*0x10);
+	val[1] = map_read(map, base + osf*0x11);
+	val[2] = map_read(map, base + osf*0x12);
+
+	if (!map_word_equal(map, qry[0], val[0]))
+		return 0;
+
+	if (!map_word_equal(map, qry[1], val[1]))
+		return 0;
+
+	if (!map_word_equal(map, qry[2], val[2]))
+		return 0;
+
+	return 1; 	/* "QRY" found */
+}
+EXPORT_SYMBOL_GPL(cfi_qry_present);
+
+int __xipram cfi_qry_mode_on(uint32_t base, struct map_info *map,
+			     struct cfi_private *cfi)
+{
+	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0x98, 0x55, base, map, cfi, cfi->device_type, NULL);
+	if (cfi_qry_present(map, base, cfi))
+		return 1;
+	/* QRY not found probably we deal with some odd CFI chips */
+	/* Some revisions of some old Intel chips? */
+	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0xFF, 0, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0x98, 0x55, base, map, cfi, cfi->device_type, NULL);
+	if (cfi_qry_present(map, base, cfi))
+		return 1;
+	/* ST M29DW chips */
+	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0x98, 0x555, base, map, cfi, cfi->device_type, NULL);
+	if (cfi_qry_present(map, base, cfi))
+		return 1;
+	/* some old SST chips, e.g. 39VF160x/39VF320x */
+	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0xAA, 0x5555, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0x55, 0x2AAA, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0x98, 0x5555, base, map, cfi, cfi->device_type, NULL);
+	if (cfi_qry_present(map, base, cfi))
+		return 1;
+	/* SST 39VF640xB */
+	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0xAA, 0x555, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0x55, 0x2AA, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0x98, 0x555, base, map, cfi, cfi->device_type, NULL);
+	if (cfi_qry_present(map, base, cfi))
+		return 1;
+	/* QRY not found */
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cfi_qry_mode_on);
+
+void __xipram cfi_qry_mode_off(uint32_t base, struct map_info *map,
+			       struct cfi_private *cfi)
+{
+	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+	cfi_send_gen_cmd(0xFF, 0, base, map, cfi, cfi->device_type, NULL);
+	/* M29W128G flashes require an additional reset command
+	   when exit qry mode */
+	if ((cfi->mfr == CFI_MFR_ST) && (cfi->id == 0x227E || cfi->id == 0x7E))
+		cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
+}
+EXPORT_SYMBOL_GPL(cfi_qry_mode_off);
+
+struct cfi_extquery *
+__xipram cfi_read_pri(struct map_info *map, __u16 adr, __u16 size, const char* name)
+{
+	struct cfi_private *cfi = map->fldrv_priv;
+	__u32 base = 0; // cfi->chips[0].start;
+	int ofs_factor = cfi->interleave * cfi->device_type;
+	int i;
+	struct cfi_extquery *extp = NULL;
+
+	if (!adr)
+		goto out;
+
+	printk(KERN_INFO "%s Extended Query Table at 0x%4.4X\n", name, adr);
+
+	extp = kmalloc(size, GFP_KERNEL);
+	if (!extp)
+		goto out;
+
+#ifdef CONFIG_MTD_XIP
+	local_irq_disable();
+#endif
+
+	/* Switch it into Query Mode */
+	cfi_qry_mode_on(base, map, cfi);
+	/* Read in the Extended Query Table */
+	for (i=0; i<size; i++) {
+		((unsigned char *)extp)[i] =
+			cfi_read_query(map, base+((adr+i)*ofs_factor));
+	}
+
+	/* Make sure it returns to read mode */
+	cfi_qry_mode_off(base, map, cfi);
+
+#ifdef CONFIG_MTD_XIP
+	(void) map_read(map, base);
+	xip_iprefetch();
+	local_irq_enable();
+#endif
+
+ out:	return extp;
+}
+
+EXPORT_SYMBOL(cfi_read_pri);
+
+void cfi_fixup(struct mtd_info *mtd, struct cfi_fixup *fixups)
+{
+	struct map_info *map = mtd->priv;
+	struct cfi_private *cfi = map->fldrv_priv;
+	struct cfi_fixup *f;
+
+	for (f=fixups; f->fixup; f++) {
+		if (((f->mfr == CFI_MFR_ANY) || (f->mfr == cfi->mfr)) &&
+		    ((f->id  == CFI_ID_ANY)  || (f->id  == cfi->id))) {
+			f->fixup(mtd);
+		}
+	}
+}
+
+EXPORT_SYMBOL(cfi_fixup);
+
+int cfi_varsize_frob(struct mtd_info *mtd, varsize_frob_t frob,
+				     loff_t ofs, size_t len, void *thunk)
+{
+	struct map_info *map = mtd->priv;
+	struct cfi_private *cfi = map->fldrv_priv;
+	unsigned long adr;
+	int chipnum, ret = 0;
+	int i, first;
+	struct mtd_erase_region_info *regions = mtd->eraseregions;
+
+	/* Check that both start and end of the requested erase are
+	 * aligned with the erasesize at the appropriate addresses.
+	 */
+
+	i = 0;
+
+	/* Skip all erase regions which are ended before the start of
+	   the requested erase. Actually, to save on the calculations,
+	   we skip to the first erase region which starts after the
+	   start of the requested erase, and then go back one.
+	*/
+
+	while (i < mtd->numeraseregions && ofs >= regions[i].offset)
+	       i++;
+	i--;
+
+	/* OK, now i is pointing at the erase region in which this
+	   erase request starts. Check the start of the requested
+	   erase range is aligned with the erase size which is in
+	   effect here.
+	*/
+
+	if (ofs & (regions[i].erasesize-1))
+		return -EINVAL;
+
+	/* Remember the erase region we start on */
+	first = i;
+
+	/* Next, check that the end of the requested erase is aligned
+	 * with the erase region at that address.
+	 */
+
+	while (i<mtd->numeraseregions && (ofs + len) >= regions[i].offset)
+		i++;
+
+	/* As before, drop back one to point at the region in which
+	   the address actually falls
+	*/
+	i--;
+
+	if ((ofs + len) & (regions[i].erasesize-1))
+		return -EINVAL;
+
+	chipnum = ofs >> cfi->chipshift;
+	adr = ofs - (chipnum << cfi->chipshift);
+
+	i=first;
+
+	while(len) {
+		int size = regions[i].erasesize;
+
+		ret = (*frob)(map, &cfi->chips[chipnum], adr, size, thunk);
+
+		if (ret)
+			return ret;
+
+		adr += size;
+		ofs += size;
+		len -= size;
+
+		if (ofs == regions[i].offset + size * regions[i].numblocks)
+			i++;
+
+		if (adr >> cfi->chipshift) {
+			adr = 0;
+			chipnum++;
+
+			if (chipnum >= cfi->numchips)
+				break;
+		}
+	}
+
+	return 0;
+}
+
+EXPORT_SYMBOL(cfi_varsize_frob);
+
+MODULE_LICENSE("GPL");