1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/mtd/chips/gen_probe.c b/drivers/mtd/chips/gen_probe.c
new file mode 100644
index 0000000000..9e53fcd760
--- /dev/null
+++ b/drivers/mtd/chips/gen_probe.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Routines common to all CFI-type probes.
+ * (C) 2001-2003 Red Hat, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/cfi.h>
+#include <linux/mtd/gen_probe.h>
+
+static struct mtd_info *check_cmd_set(struct map_info *, int);
+static struct cfi_private *genprobe_ident_chips(struct map_info *map,
+						struct chip_probe *cp);
+static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
+			     struct cfi_private *cfi);
+
+struct mtd_info *mtd_do_chip_probe(struct map_info *map, struct chip_probe *cp)
+{
+	struct mtd_info *mtd;
+	struct cfi_private *cfi;
+
+	/* First probe the map to see if we have CFI stuff there. */
+	cfi = genprobe_ident_chips(map, cp);
+
+	if (!cfi)
+		return NULL;
+
+	map->fldrv_priv = cfi;
+	/* OK we liked it. Now find a driver for the command set it talks */
+
+	mtd = check_cmd_set(map, 1); /* First the primary cmdset */
+	if (!mtd)
+		mtd = check_cmd_set(map, 0); /* Then the secondary */
+
+	if (mtd) {
+		if (mtd->size > map->size) {
+			printk(KERN_WARNING "Reducing visibility of %ldKiB chip to %ldKiB\n",
+			       (unsigned long)mtd->size >> 10,
+			       (unsigned long)map->size >> 10);
+			mtd->size = map->size;
+		}
+		return mtd;
+	}
+
+	printk(KERN_WARNING"gen_probe: No supported Vendor Command Set found\n");
+
+	kfree(cfi->cfiq);
+	kfree(cfi);
+	map->fldrv_priv = NULL;
+	return NULL;
+}
+EXPORT_SYMBOL(mtd_do_chip_probe);
+
+
+static struct cfi_private *genprobe_ident_chips(struct map_info *map, struct chip_probe *cp)
+{
+	struct cfi_private cfi;
+	struct cfi_private *retcfi;
+	unsigned long *chip_map;
+	int max_chips;
+	int i, j;
+
+	memset(&cfi, 0, sizeof(cfi));
+
+	/* Call the probetype-specific code with all permutations of
+	   interleave and device type, etc. */
+	if (!genprobe_new_chip(map, cp, &cfi)) {
+		/* The probe didn't like it */
+		pr_debug("%s: Found no %s device at location zero\n",
+			 cp->name, map->name);
+		return NULL;
+	}
+
+#if 0 /* Let the CFI probe routine do this sanity check. The Intel and AMD
+	 probe routines won't ever return a broken CFI structure anyway,
+	 because they make them up themselves.
+      */
+	if (cfi.cfiq->NumEraseRegions == 0) {
+		printk(KERN_WARNING "Number of erase regions is zero\n");
+		kfree(cfi.cfiq);
+		return NULL;
+	}
+#endif
+	cfi.chipshift = cfi.cfiq->DevSize;
+
+	if (cfi_interleave_is_1(&cfi)) {
+		;
+	} else if (cfi_interleave_is_2(&cfi)) {
+		cfi.chipshift++;
+	} else if (cfi_interleave_is_4((&cfi))) {
+		cfi.chipshift += 2;
+	} else if (cfi_interleave_is_8(&cfi)) {
+		cfi.chipshift += 3;
+	} else {
+		BUG();
+	}
+
+	cfi.numchips = 1;
+
+	/*
+	 * Allocate memory for bitmap of valid chips.
+	 * Align bitmap storage size to full byte.
+	 */
+	max_chips = map->size >> cfi.chipshift;
+	if (!max_chips) {
+		printk(KERN_WARNING "NOR chip too large to fit in mapping. Attempting to cope...\n");
+		max_chips = 1;
+	}
+
+	chip_map = bitmap_zalloc(max_chips, GFP_KERNEL);
+	if (!chip_map) {
+		kfree(cfi.cfiq);
+		return NULL;
+	}
+
+	set_bit(0, chip_map); /* Mark first chip valid */
+
+	/*
+	 * Now probe for other chips, checking sensibly for aliases while
+	 * we're at it. The new_chip probe above should have let the first
+	 * chip in read mode.
+	 */
+
+	for (i = 1; i < max_chips; i++) {
+		cp->probe_chip(map, i << cfi.chipshift, chip_map, &cfi);
+	}
+
+	/*
+	 * Now allocate the space for the structures we need to return to
+	 * our caller, and copy the appropriate data into them.
+	 */
+
+	retcfi = kmalloc(struct_size(retcfi, chips, cfi.numchips), GFP_KERNEL);
+
+	if (!retcfi) {
+		kfree(cfi.cfiq);
+		bitmap_free(chip_map);
+		return NULL;
+	}
+
+	memcpy(retcfi, &cfi, sizeof(cfi));
+	memset(&retcfi->chips[0], 0, sizeof(struct flchip) * cfi.numchips);
+
+	for (i = 0, j = 0; (j < cfi.numchips) && (i < max_chips); i++) {
+		if(test_bit(i, chip_map)) {
+			struct flchip *pchip = &retcfi->chips[j++];
+
+			pchip->start = (i << cfi.chipshift);
+			pchip->state = FL_READY;
+			init_waitqueue_head(&pchip->wq);
+			mutex_init(&pchip->mutex);
+		}
+	}
+
+	bitmap_free(chip_map);
+	return retcfi;
+}
+
+
+static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
+			     struct cfi_private *cfi)
+{
+	int min_chips = (map_bankwidth(map)/4?:1); /* At most 4-bytes wide. */
+	int max_chips = map_bankwidth(map); /* And minimum 1 */
+	int nr_chips, type;
+
+	for (nr_chips = max_chips; nr_chips >= min_chips; nr_chips >>= 1) {
+
+		if (!cfi_interleave_supported(nr_chips))
+		    continue;
+
+		cfi->interleave = nr_chips;
+
+		/* Minimum device size. Don't look for one 8-bit device
+		   in a 16-bit bus, etc. */
+		type = map_bankwidth(map) / nr_chips;
+
+		for (; type <= CFI_DEVICETYPE_X32; type<<=1) {
+			cfi->device_type = type;
+
+			if (cp->probe_chip(map, 0, NULL, cfi))
+				return 1;
+		}
+	}
+	return 0;
+}
+
+typedef struct mtd_info *cfi_cmdset_fn_t(struct map_info *, int);
+
+extern cfi_cmdset_fn_t cfi_cmdset_0001;
+extern cfi_cmdset_fn_t cfi_cmdset_0002;
+extern cfi_cmdset_fn_t cfi_cmdset_0020;
+
+static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
+						  int primary)
+{
+	struct cfi_private *cfi = map->fldrv_priv;
+	__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
+#ifdef CONFIG_MODULES
+	cfi_cmdset_fn_t *probe_function;
+	char *probename;
+
+	probename = kasprintf(GFP_KERNEL, "cfi_cmdset_%4.4X", type);
+	if (!probename)
+		return NULL;
+
+	probe_function = __symbol_get(probename);
+	if (!probe_function) {
+		request_module("cfi_cmdset_%4.4X", type);
+		probe_function = __symbol_get(probename);
+	}
+	kfree(probename);
+
+	if (probe_function) {
+		struct mtd_info *mtd;
+
+		mtd = (*probe_function)(map, primary);
+		/* If it was happy, it'll have increased its own use count */
+		symbol_put_addr(probe_function);
+		return mtd;
+	}
+#endif
+	printk(KERN_NOTICE "Support for command set %04X not present\n", type);
+
+	return NULL;
+}
+
+static struct mtd_info *check_cmd_set(struct map_info *map, int primary)
+{
+	struct cfi_private *cfi = map->fldrv_priv;
+	__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
+
+	if (type == P_ID_NONE || type == P_ID_RESERVED)
+		return NULL;
+
+	switch(type){
+		/* We need these for the !CONFIG_MODULES case,
+		   because symbol_get() doesn't work there */
+#ifdef CONFIG_MTD_CFI_INTELEXT
+	case P_ID_INTEL_EXT:
+	case P_ID_INTEL_STD:
+	case P_ID_INTEL_PERFORMANCE:
+		return cfi_cmdset_0001(map, primary);
+#endif
+#ifdef CONFIG_MTD_CFI_AMDSTD
+	case P_ID_AMD_STD:
+	case P_ID_SST_OLD:
+	case P_ID_WINBOND:
+		return cfi_cmdset_0002(map, primary);
+#endif
+#ifdef CONFIG_MTD_CFI_STAA
+        case P_ID_ST_ADV:
+		return cfi_cmdset_0020(map, primary);
+#endif
+	default:
+		return cfi_cmdset_unknown(map, primary);
+	}
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("Helper routines for flash chip probe code");