diff --git a/include/programmer.h b/include/programmer.h
index 527eeb3..b0eac19 100644
--- a/include/programmer.h
+++ b/include/programmer.h
@@ -102,15 +102,15 @@
 
 struct bitbang_spi_master {
 	/* Note that CS# is active low, so val=0 means the chip is active. */
-	void (*set_cs) (int val);
-	void (*set_sck) (int val);
-	void (*set_mosi) (int val);
-	int (*get_miso) (void);
-	void (*request_bus) (void);
-	void (*release_bus) (void);
+	void (*set_cs) (int val, void *spi_data);
+	void (*set_sck) (int val, void *spi_data);
+	void (*set_mosi) (int val, void *spi_data);
+	int (*get_miso) (void *spi_data);
+	void (*request_bus) (void *spi_data);
+	void (*release_bus) (void *spi_data);
 	/* optional functions to optimize xfers */
-	void (*set_sck_set_mosi) (int sck, int mosi);
-	int (*set_sck_get_miso) (int sck);
+	void (*set_sck_set_mosi) (int sck, int mosi, void *spi_data);
+	int (*set_sck_get_miso) (int sck, void *spi_data);
 	/* Length of half a clock period in usecs. */
 	unsigned int half_period;
 };