diff --git a/at45db.c b/at45db.c
index f84f3f4..2768ace 100644
--- a/at45db.c
+++ b/at45db.c
@@ -172,14 +172,11 @@
 }
 
 /* Adapt chip entry for AT45DB* chips that support multiple page sizes. */
-int spi_prepare_at45db(struct flashctx *const flash, const enum preparation_steps prep)
+int spi_prepare_at45db(struct flashctx *const flash)
 {
 	struct flashchip *const chip = flash->chip;
 	uint8_t status;
 
-	if (prep != PREPARE_POST_PROBE)
-		return 0;
-
 	/* Power-of-2 check */
 	if (chip->page_size & (chip->page_size - 1))
 		return 0;
diff --git a/edi.c b/edi.c
index 0f83a40..efe41c5 100644
--- a/edi.c
+++ b/edi.c
@@ -470,7 +470,7 @@
 	return 0;
 }
 
-static void edi_finish(struct flashctx *flash)
+void edi_finish(struct flashctx *flash)
 {
 	const struct spi_master *const spi = flash->mst.spi;
 
@@ -502,19 +502,15 @@
 	return edi_chip_probe(spi);
 }
 
-int edi_prepare(struct flashctx *flash, enum preparation_steps step)
+int edi_prepare(struct flashctx *flash)
 {
 	int rc;
 
-	if (step < PREPARE_FULL)
-		return 0;
-
 	rc = edi_8051_reset(flash->mst.spi);
 	if (rc < 0) {
 		msg_perr("%s: Unable to reset 8051!\n", __func__);
 		return rc;
 	}
 
-	flash->chip->finish_access = edi_finish;
 	return 0;
 }
diff --git a/flashchips.c b/flashchips.c
index e38f5e4..dfea1f6 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -4145,6 +4145,7 @@
 		.voltage	= {2700, 3600},
 		.gran		= write_gran_128bytes,
 		.prepare_access	= edi_prepare,
+		.finish_access	= edi_finish,
 	},
 
 	{
diff --git a/flashprog.c b/flashprog.c
index ca2038c..f647f75 100644
--- a/flashprog.c
+++ b/flashprog.c
@@ -1548,9 +1548,6 @@
 		return 1;
 	}
 
-	if (flash->chip->prepare_access && flash->chip->prepare_access(flash, PREPARE_FULL))
-		return 1;
-
 	/* Initialize chip_restore_fn_count before chip unlock calls. */
 	flash->chip_restore_fn_count = 0;
 
@@ -1565,8 +1562,6 @@
 void finalize_flash_access(struct flashctx *const flash)
 {
 	deregister_chip_restore(flash);
-	if (flash->chip->finish_access)
-		flash->chip->finish_access(flash);
 }
 
 /**
diff --git a/include/chipdrivers/edi.h b/include/chipdrivers/edi.h
index 4d641cc..ad0e1db 100644
--- a/include/chipdrivers/edi.h
+++ b/include/chipdrivers/edi.h
@@ -29,6 +29,7 @@
 int edi_chip_block_erase(struct flashprog_flashctx *, unsigned int page, unsigned int size);
 int edi_chip_write(struct flashprog_flashctx *, const uint8_t *buf, unsigned int start, unsigned int len);
 int edi_chip_read(struct flashprog_flashctx *, uint8_t *buf, unsigned int start, unsigned int len);
-int edi_prepare(struct flashprog_flashctx *, enum preparation_steps);
+int edi_prepare(struct flashprog_flashctx *);
+void edi_finish(struct flashprog_flashctx *);
 
 #endif /* !__CHIPDRIVERS_EDI_H__ */
diff --git a/include/chipdrivers/memory_bus.h b/include/chipdrivers/memory_bus.h
index b4eede4..86a82a0 100644
--- a/include/chipdrivers/memory_bus.h
+++ b/include/chipdrivers/memory_bus.h
@@ -115,9 +115,8 @@
 void *programmer_map_flash_data(const struct par_master *, chipsize_t, const char *descr);
 void programmer_unmap_flash_region(const struct par_master *, void *, chipsize_t);
 
-enum preparation_steps;
-int prepare_memory_access(struct flashprog_flashctx *, enum preparation_steps);
-int prepare_memory_register_access(struct flashprog_flashctx *, enum preparation_steps);
+int prepare_memory_access(struct flashprog_flashctx *);
+int prepare_memory_register_access(struct flashprog_flashctx *);
 void finish_memory_access(struct flashprog_flashctx *);
 
 #endif /* !__CHIPDRIVERS_MEMORY_BUS_H__ */
diff --git a/include/chipdrivers/opaque.h b/include/chipdrivers/opaque.h
index d6d3eba..8d9f660 100644
--- a/include/chipdrivers/opaque.h
+++ b/include/chipdrivers/opaque.h
@@ -25,8 +25,7 @@
 
 struct found_id *probe_opaque(const struct bus_probe *, const struct master_common *, const struct flashchip *);
 
-enum preparation_steps;
-int prepare_opaque(struct flashprog_flashctx *, enum preparation_steps);
+int prepare_opaque(struct flashprog_flashctx *);
 
 int read_opaque(struct flashprog_flashctx *, uint8_t *buf, unsigned int start, unsigned int len);
 int write_opaque(struct flashprog_flashctx *, const uint8_t *buf, unsigned int start, unsigned int len);
diff --git a/include/chipdrivers/spi.h b/include/chipdrivers/spi.h
index 94a6a1f..d99d903 100644
--- a/include/chipdrivers/spi.h
+++ b/include/chipdrivers/spi.h
@@ -57,8 +57,7 @@
 int spi_write_chunked(struct flashprog_flashctx *, const uint8_t *buf, unsigned int start, unsigned int len, unsigned int chunksize);
 int spi_set_extended_address(struct flashprog_flashctx *, uint8_t addr_high);
 
-enum preparation_steps;
-int spi_prepare_io(struct flashprog_flashctx *, enum preparation_steps);
+int spi_prepare_io(struct flashprog_flashctx *);
 void spi_finish_io(struct flashprog_flashctx *);
 
 enum flash_reg;
@@ -107,7 +106,7 @@
 int spi_disable_blockprotect_sst26_global_unprotect(struct flashprog_flashctx *);
 
 /* at45db.c */
-int spi_prepare_at45db(struct flashprog_flashctx *, enum preparation_steps);
+int spi_prepare_at45db(struct flashprog_flashctx *);
 int spi_prettyprint_status_register_at45db(struct flashprog_flashctx *);
 int spi_disable_blockprotect_at45db(struct flashprog_flashctx *);
 int spi_read_at45db(struct flashprog_flashctx *, uint8_t *buf, unsigned int start, unsigned int len);
@@ -132,6 +131,6 @@
 
 /* sfdp.c */
 struct found_id *probe_spi_sfdp(const struct bus_probe *, const struct master_common *, const struct flashchip *);
-int spi_prepare_sfdp(struct flashprog_flashctx *, enum preparation_steps);
+int spi_prepare_sfdp(struct flashprog_flashctx *);
 
 #endif /* !__CHIPDRIVERS_SPI_H__ */
diff --git a/include/flash.h b/include/flash.h
index 32824a7..5566067 100644
--- a/include/flash.h
+++ b/include/flash.h
@@ -246,11 +246,6 @@
 
 struct wp_bits;
 
-enum preparation_steps {
-	PREPARE_POST_PROBE,
-	PREPARE_FULL,
-};
-
 struct flashchip {
 	const char *vendor;
 	const char *name;
@@ -412,7 +407,7 @@
 	/* and determines what protection range they select. */
 	void (*decode_range)(size_t *start, size_t *len, const struct wp_bits *, size_t chip_len);
 
-	int (*prepare_access)(struct flashctx *, enum preparation_steps);
+	int (*prepare_access)(struct flashctx *);
 	void (*finish_access)(struct flashctx *);
 };
 
diff --git a/libflashprog.c b/libflashprog.c
index 900ecc2..212293f 100644
--- a/libflashprog.c
+++ b/libflashprog.c
@@ -300,15 +300,19 @@
 	*flash->chip = *chip;
 	flash->mst.common = bus; /* `mst` is a union, so we need only one pointer */
 
-	if (chip->prepare_access && chip->prepare_access(flash, PREPARE_POST_PROBE))
-		goto free_flash;
+	if (chip->prepare_access && chip->prepare_access(flash)) {
+		free(flash);
+		return 4;
+	}
 
 	/* Fill default layout covering the whole chip. */
 	if (flashprog_layout_new(&flash->default_layout) ||
 	    flashprog_layout_add_region(flash->default_layout,
 			0, flash->chip->total_size * 1024 - 1, "complete flash") ||
-	    flashprog_layout_include_region(flash->default_layout, "complete flash"))
-		goto free_flash;
+	    flashprog_layout_include_region(flash->default_layout, "complete flash")) {
+		flashprog_flash_release(flash);
+		return 1;
+	}
 
 	char *const tmp = flashbuses_to_text(flash->chip->bustype);
 	msg_cinfo("Using %s flash chip \"%s\" (%d kB, %s) ",
@@ -323,18 +327,8 @@
 	if (flash->chip->printlock)
 		flash->chip->printlock(flash);
 
-	if (flash->chip->finish_access)
-		flash->chip->finish_access(flash);
-
 	*flashctx = flash;
 	return 0;
-
-free_flash:
-	if (flash->chip && flash->chip->finish_access)
-		flash->chip->finish_access(flash);
-	free(flash->chip);
-	free(flash);
-	return 4;
 }
 
 /**
@@ -389,6 +383,8 @@
 	if (!flashctx)
 		return;
 
+	if (flashctx->chip->finish_access)
+		flashctx->chip->finish_access(flashctx);
 	flashprog_layout_release(flashctx->default_layout);
 	free(flashctx->chip);
 	free(flashctx);
diff --git a/memory_bus.c b/memory_bus.c
index fafe385..edc48e6 100644
--- a/memory_bus.c
+++ b/memory_bus.c
@@ -61,7 +61,7 @@
 	return addr;
 }
 
-int prepare_memory_access(struct flashctx *flash, enum preparation_steps prep)
+int prepare_memory_access(struct flashctx *flash)
 {
 	const struct par_master *const par = flash->mst.par;
 
@@ -80,11 +80,11 @@
 	return 0;
 }
 
-int prepare_memory_register_access(struct flashctx *flash, enum preparation_steps prep)
+int prepare_memory_register_access(struct flashctx *flash)
 {
 	const struct par_master *const par = flash->mst.par;
 
-	if (prepare_memory_access(flash, prep))
+	if (prepare_memory_access(flash))
 		return 1;
 
 	/*
diff --git a/opaque.c b/opaque.c
index 6db03cc..d62fe3b 100644
--- a/opaque.c
+++ b/opaque.c
@@ -47,10 +47,8 @@
 	return found;
 }
 
-int prepare_opaque(struct flashctx *flash, enum preparation_steps step)
+int prepare_opaque(struct flashctx *flash)
 {
-	if (step != PREPARE_POST_PROBE)
-		return 0;
 	return flash->mst.opaque->prepare(flash) ? 0 : -1;
 }
 
diff --git a/sfdp.c b/sfdp.c
index a324f9c..b1d7777 100644
--- a/sfdp.c
+++ b/sfdp.c
@@ -342,7 +342,7 @@
 	return 0;
 }
 
-int spi_prepare_sfdp(struct flashctx *flash, enum preparation_steps step)
+int spi_prepare_sfdp(struct flashctx *flash)
 {
 	const struct spi_master *const spi = flash->mst.spi;
 	int ret;
@@ -355,9 +355,6 @@
 	uint8_t *hbuf;
 	uint8_t *tbuf;
 
-	if (step != PREPARE_POST_PROBE)
-		return 0;
-
 	ret = spi_sfdp_read_sfdp(spi, 0x04, buf, 3);
 	if (ret) {
 		msg_cdbg("Receiving SFDP revision and number of parameter "
@@ -490,7 +487,12 @@
 		  "Thanks for your help!\n"
 		  "===\n");
 
-	return 0;
+	/* Chain preparation in case we replaced the .prepare_access
+	   pointer, e.g. spi_prepare_io() is needed for 4BA mode. */
+	if (flash->chip->prepare_access != spi_prepare_sfdp)
+		ret = flash->chip->prepare_access(flash);
+
+	return ret;
 }
 
 struct found_id *probe_spi_sfdp(const struct bus_probe *probe,
diff --git a/spi25_prepare.c b/spi25_prepare.c
index aaf240d..03fb54b 100644
--- a/spi25_prepare.c
+++ b/spi25_prepare.c
@@ -248,11 +248,8 @@
 	return fast_read_copy;
 }
 
-int spi_prepare_io(struct flashctx *const flash, const enum preparation_steps prep)
+int spi_prepare_io(struct flashctx *const flash)
 {
-	if (prep != PREPARE_FULL)
-		return 0;
-
 	int ret = spi_prepare_4ba(flash);
 	if (ret)
 		return ret;