diff --git a/bitbang_spi.c b/bitbang_spi.c
index d22b6fc..f319957 100644
--- a/bitbang_spi.c
+++ b/bitbang_spi.c
@@ -103,7 +103,7 @@
 
 	/* Cast away `const`, but local code must ensure it's still treated as such. */
 	mst.data = (struct bitbang_spi_master *)master;
-	register_spi_master(&mst);
+	register_spi_master(&mst, NULL);
 
 	/* Only mess with the bus if we're sure nobody else uses it. */
 	bitbang_spi_request_bus(master);
diff --git a/buspirate_spi.c b/buspirate_spi.c
index 2f58f0a..6c9ee4a 100644
--- a/buspirate_spi.c
+++ b/buspirate_spi.c
@@ -592,7 +592,7 @@
 		ret = 1;
 		goto init_err_cleanup_exit;
 	}
-	register_spi_master(&spi_master_buspirate);
+	register_spi_master(&spi_master_buspirate, NULL);
 
 	return 0;
 
diff --git a/ch341a_spi.c b/ch341a_spi.c
index 67a78ee..e26f9e9 100644
--- a/ch341a_spi.c
+++ b/ch341a_spi.c
@@ -507,7 +507,7 @@
 		goto dealloc_transfers;
 
 	register_shutdown(ch341a_spi_shutdown, NULL);
-	register_spi_master(&spi_master_ch341a_spi);
+	register_spi_master(&spi_master_ch341a_spi, NULL);
 
 	return 0;
 
diff --git a/dediprog.c b/dediprog.c
index 841cc02..69c4782 100644
--- a/dediprog.c
+++ b/dediprog.c
@@ -1309,7 +1309,7 @@
 		goto init_err_cleanup_exit;
 
 	spi_master_dediprog.data = dp_data;
-	return register_spi_master(&spi_master_dediprog);
+	return register_spi_master(&spi_master_dediprog, NULL);
 
 init_err_cleanup_exit:
 	dediprog_shutdown(dp_data);
diff --git a/digilent_spi.c b/digilent_spi.c
index bcd73ae..d39d686 100644
--- a/digilent_spi.c
+++ b/digilent_spi.c
@@ -447,7 +447,7 @@
 		goto close_handle;
 
 	register_shutdown(digilent_spi_shutdown, NULL);
-	register_spi_master(&spi_master_digilent_spi);
+	register_spi_master(&spi_master_digilent_spi, NULL);
 
 	return 0;
 
diff --git a/dirtyjtag_spi.c b/dirtyjtag_spi.c
index 5b08952..c9e921f 100644
--- a/dirtyjtag_spi.c
+++ b/dirtyjtag_spi.c
@@ -301,7 +301,7 @@
 		goto cleanup_libusb_handle;
 
 	spi_master_dirtyjtag_spi.data = djtag_data;
-	return register_spi_master(&spi_master_dirtyjtag_spi);
+	return register_spi_master(&spi_master_dirtyjtag_spi, NULL);
 
 cleanup_libusb_handle:
 	libusb_attach_kernel_driver(handle, 0);
diff --git a/dummyflasher.c b/dummyflasher.c
index 72d0259..01597f9 100644
--- a/dummyflasher.c
+++ b/dummyflasher.c
@@ -499,7 +499,7 @@
 		register_par_master(&par_master_dummy,
 				    dummy_buses_supported & BUS_NONSPI);
 	if (dummy_buses_supported & BUS_SPI)
-		register_spi_master(&spi_master_dummyflasher);
+		register_spi_master(&spi_master_dummyflasher, NULL);
 
 	return 0;
 }
diff --git a/ft2232_spi.c b/ft2232_spi.c
index 1f813fb..2737dae 100644
--- a/ft2232_spi.c
+++ b/ft2232_spi.c
@@ -701,7 +701,7 @@
 		ret = -9;
 		goto ftdi_err;
 	}
-	register_spi_master(&spi_master_ft2232);
+	register_spi_master(&spi_master_ft2232, NULL);
 
 	return 0;
 
diff --git a/ichspi.c b/ichspi.c
index 0996d2d..929dcc4 100644
--- a/ichspi.c
+++ b/ichspi.c
@@ -1824,7 +1824,7 @@
 		}
 		ich_init_opcodes();
 		ich_set_bbar(0);
-		register_spi_master(&spi_master_ich7);
+		register_spi_master(&spi_master_ich7, NULL);
 		break;
 	case CHIPSET_ICH8:
 	default:		/* Future version might behave the same */
@@ -2062,7 +2062,7 @@
 
 			register_opaque_master(&opaque_master_ich_hwseq);
 		} else {
-			register_spi_master(&spi_master_ich9);
+			register_spi_master(&spi_master_ich9, NULL);
 		}
 		break;
 	}
@@ -2092,7 +2092,7 @@
 	/* Not sure if it speaks all these bus protocols. */
 	internal_buses_supported &= BUS_LPC | BUS_FWH;
 	ich_generation = CHIPSET_ICH7;
-	register_spi_master(&spi_master_via);
+	register_spi_master(&spi_master_via, NULL);
 
 	msg_pdbg("0x00: 0x%04x     (SPIS)\n", mmio_readw(ich_spibar + 0));
 	msg_pdbg("0x02: 0x%04x     (SPIC)\n", mmio_readw(ich_spibar + 2));
diff --git a/it87spi.c b/it87spi.c
index 5713bde..0903911 100644
--- a/it87spi.c
+++ b/it87spi.c
@@ -224,7 +224,7 @@
 	if (internal_buses_supported & BUS_SPI)
 		msg_pdbg("Overriding chipset SPI with IT87 SPI.\n");
 	/* FIXME: Add the SPI bus or replace the other buses with it? */
-	register_spi_master(&spi_master_it87xx);
+	register_spi_master(&spi_master_it87xx, NULL);
 	return 0;
 }
 
diff --git a/jlink_spi.c b/jlink_spi.c
index 7fcfc35..ffa547d 100644
--- a/jlink_spi.c
+++ b/jlink_spi.c
@@ -518,7 +518,7 @@
 
 	if (register_shutdown(jlink_spi_shutdown, jlink_data))
 		goto init_err;
-	register_spi_master(&spi_master_jlink_spi);
+	register_spi_master(&spi_master_jlink_spi, NULL);
 
 	return 0;
 
diff --git a/linux_spi.c b/linux_spi.c
index 033c94a..697a8a2 100644
--- a/linux_spi.c
+++ b/linux_spi.c
@@ -192,7 +192,7 @@
 		free(spi_data);
 		goto init_err;
 	}
-	register_spi_master(&spi_master_linux);
+	register_spi_master(&spi_master_linux, NULL);
 	return 0;
 
 init_err:
diff --git a/mstarddc_spi.c b/mstarddc_spi.c
index 9c53f14..460a382 100644
--- a/mstarddc_spi.c
+++ b/mstarddc_spi.c
@@ -146,7 +146,7 @@
 	register_shutdown(mstarddc_spi_shutdown, NULL);
 
 	// Register programmer
-	register_spi_master(&spi_master_mstarddc);
+	register_spi_master(&spi_master_mstarddc, NULL);
 out:
 	free(i2c_device);
 	return ret;
diff --git a/ni845x_spi.c b/ni845x_spi.c
index 1df76c0..6e274ac 100644
--- a/ni845x_spi.c
+++ b/ni845x_spi.c
@@ -481,7 +481,7 @@
 		return 1;
 	}
 
-	register_spi_master(&spi_programmer_ni845x);
+	register_spi_master(&spi_programmer_ni845x, NULL);
 
 	return 0;
 }
diff --git a/pickit2_spi.c b/pickit2_spi.c
index 9c78138..5d0b573 100644
--- a/pickit2_spi.c
+++ b/pickit2_spi.c
@@ -500,7 +500,7 @@
 
 	if (register_shutdown(pickit2_shutdown, pickit2_data))
 		goto init_err_cleanup_exit;
-	register_spi_master(&spi_master_pickit2);
+	register_spi_master(&spi_master_pickit2, NULL);
 
 	return 0;
 
diff --git a/programmer.h b/programmer.h
index 9217c0d..f7ce7bc 100644
--- a/programmer.h
+++ b/programmer.h
@@ -328,7 +328,7 @@
 int default_spi_read(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 int default_spi_write_256(struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len);
 int default_spi_write_aai(struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len);
-int register_spi_master(const struct spi_master *mst);
+int register_spi_master(const struct spi_master *mst, void *data);
 
 /* The following enum is needed by ich_descriptor_tool and ich* code as well as in chipset_enable.c. */
 enum ich_chipset {
diff --git a/sb600spi.c b/sb600spi.c
index 7727118..3a1445a 100644
--- a/sb600spi.c
+++ b/sb600spi.c
@@ -701,9 +701,9 @@
 
 	/* Starting with Yangtze the SPI controller got a different interface with a much bigger buffer. */
 	if (amd_gen < CHIPSET_YANGTZE)
-		register_spi_master(&spi_master_sb600);
+		register_spi_master(&spi_master_sb600, NULL);
 	else
-		register_spi_master(&spi_master_yangtze);
+		register_spi_master(&spi_master_yangtze, NULL);
 	return 0;
 }
 
diff --git a/serprog.c b/serprog.c
index 7acba36..2626be1 100644
--- a/serprog.c
+++ b/serprog.c
@@ -704,7 +704,7 @@
 	sp_streamed_transmit_bytes = 0;
 	sp_opbuf_usage = 0;
 	if (serprog_buses_supported & BUS_SPI)
-		register_spi_master(&spi_master_serprog);
+		register_spi_master(&spi_master_serprog, NULL);
 	if (serprog_buses_supported & BUS_NONSPI)
 		register_par_master(&par_master_serprog, serprog_buses_supported & BUS_NONSPI);
 	return 0;
diff --git a/spi.c b/spi.c
index 86141cc..5ee9a24 100644
--- a/spi.c
+++ b/spi.c
@@ -129,7 +129,7 @@
 	return flash->mst->spi.write_aai(flash, buf, start, len);
 }
 
-int register_spi_master(const struct spi_master *mst)
+int register_spi_master(const struct spi_master *mst, void *data)
 {
 	struct registered_master rmst;
 
@@ -146,5 +146,7 @@
 
 	rmst.buses_supported = BUS_SPI;
 	rmst.spi = *mst;
+	if (data)
+		rmst.spi.data = data;
 	return register_master(&rmst);
 }
diff --git a/stlinkv3_spi.c b/stlinkv3_spi.c
index 68790cf..50b5c85 100644
--- a/stlinkv3_spi.c
+++ b/stlinkv3_spi.c
@@ -507,7 +507,7 @@
 	if (register_shutdown(stlinkv3_spi_shutdown, NULL))
 		goto init_err_cleanup_exit;
 
-	if (register_spi_master(&spi_programmer_stlinkv3))
+	if (register_spi_master(&spi_programmer_stlinkv3, NULL))
 		return 1; /* shutdown function does cleanup */
 
 	return 0;
diff --git a/usbblaster_spi.c b/usbblaster_spi.c
index 5659535..8b442db 100644
--- a/usbblaster_spi.c
+++ b/usbblaster_spi.c
@@ -112,7 +112,7 @@
 		return -1;
 	}
 
-	register_spi_master(&spi_master_usbblaster);
+	register_spi_master(&spi_master_usbblaster, NULL);
 	return 0;
 }
 
diff --git a/wbsio_spi.c b/wbsio_spi.c
index 9145814..d7c1b0b 100644
--- a/wbsio_spi.c
+++ b/wbsio_spi.c
@@ -85,7 +85,7 @@
 	msg_pdbg("%s: Winbond saved on 4 register bits so max chip size is "
 		 "1024 kB!\n", __func__);
 	max_rom_decode.spi = 1024 * 1024;
-	register_spi_master(&spi_master_wbsio);
+	register_spi_master(&spi_master_wbsio, NULL);
 
 	return 0;
 }