m68k/scsi: gvp11 - Extract check_wd33c93()

Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

drivers/scsi/gvp11.c

@@ -22,6 +22,8 @@
 #include <linux/stat.h>
 
 
+#define CHECK_WD33C93
+
 static irqreturn_t gvp11_intr(int irq, void *data)
 {
 	struct Scsi_Host *instance = data;
@@ -167,7 +169,85 @@ static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
 	}
 }
 
-#define CHECK_WD33C93
+static int __init check_wd33c93(gvp11_scsiregs *regs)
+{
+#ifdef CHECK_WD33C93
+	volatile unsigned char *sasr_3393, *scmd_3393;
+	unsigned char save_sasr;
+	unsigned char q, qq;
+
+	/*
+	 * These darn GVP boards are a problem - it can be tough to tell
+	 * whether or not they include a SCSI controller. This is the
+	 * ultimate Yet-Another-GVP-Detection-Hack in that it actually
+	 * probes for a WD33c93 chip: If we find one, it's extremely
+	 * likely that this card supports SCSI, regardless of Product_
+	 * Code, Board_Size, etc.
+	 */
+
+	/* Get pointers to the presumed register locations and save contents */
+
+	sasr_3393 = &regs->SASR;
+	scmd_3393 = &regs->SCMD;
+	save_sasr = *sasr_3393;
+
+	/* First test the AuxStatus Reg */
+
+	q = *sasr_3393;	/* read it */
+	if (q & 0x08)	/* bit 3 should always be clear */
+		return -ENODEV;
+	*sasr_3393 = WD_AUXILIARY_STATUS;	/* setup indirect address */
+	if (*sasr_3393 == WD_AUXILIARY_STATUS) {	/* shouldn't retain the write */
+		*sasr_3393 = save_sasr;	/* Oops - restore this byte */
+		return -ENODEV;
+	}
+	if (*sasr_3393 != q) {	/* should still read the same */
+		*sasr_3393 = save_sasr;	/* Oops - restore this byte */
+		return -ENODEV;
+	}
+	if (*scmd_3393 != q)	/* and so should the image at 0x1f */
+		return -ENODEV;
+
+	/*
+	 * Ok, we probably have a wd33c93, but let's check a few other places
+	 * for good measure. Make sure that this works for both 'A and 'B
+	 * chip versions.
+	 */
+
+	*sasr_3393 = WD_SCSI_STATUS;
+	q = *scmd_3393;
+	*sasr_3393 = WD_SCSI_STATUS;
+	*scmd_3393 = ~q;
+	*sasr_3393 = WD_SCSI_STATUS;
+	qq = *scmd_3393;
+	*sasr_3393 = WD_SCSI_STATUS;
+	*scmd_3393 = q;
+	if (qq != q)	/* should be read only */
+		return -ENODEV;
+	*sasr_3393 = 0x1e;	/* this register is unimplemented */
+	q = *scmd_3393;
+	*sasr_3393 = 0x1e;
+	*scmd_3393 = ~q;
+	*sasr_3393 = 0x1e;
+	qq = *scmd_3393;
+	*sasr_3393 = 0x1e;
+	*scmd_3393 = q;
+	if (qq != q || qq != 0xff)	/* should be read only, all 1's */
+		return -ENODEV;
+	*sasr_3393 = WD_TIMEOUT_PERIOD;
+	q = *scmd_3393;
+	*sasr_3393 = WD_TIMEOUT_PERIOD;
+	*scmd_3393 = ~q;
+	*sasr_3393 = WD_TIMEOUT_PERIOD;
+	qq = *scmd_3393;
+	*sasr_3393 = WD_TIMEOUT_PERIOD;
+	*scmd_3393 = q;
+	if (qq != (~q & 0xff))	/* should be read/write */
+		return -ENODEV;
+#endif /* CHECK_WD33C93 */
+
+	return 0;
+}
 
 int __init gvp11_detect(struct scsi_host_template *tpnt)
 {
@@ -181,11 +261,6 @@ int __init gvp11_detect(struct scsi_host_template *tpnt)
 	gvp11_scsiregs *regs;
 	wd33c93_regs wdregs;
 	int num_gvp11 = 0;
-#ifdef CHECK_WD33C93
-	volatile unsigned char *sasr_3393, *scmd_3393;
-	unsigned char save_sasr;
-	unsigned char q, qq;
-#endif
 
 	if (!MACH_IS_AMIGA || called)
 		return 0;
@@ -226,77 +301,9 @@ int __init gvp11_detect(struct scsi_host_template *tpnt)
 		if (!request_mem_region(address, 256, "wd33c93"))
 			continue;
 
-#ifdef CHECK_WD33C93
-
-		/*
-		 * These darn GVP boards are a problem - it can be tough to tell
-		 * whether or not they include a SCSI controller. This is the
-		 * ultimate Yet-Another-GVP-Detection-Hack in that it actually
-		 * probes for a WD33c93 chip: If we find one, it's extremely
-		 * likely that this card supports SCSI, regardless of Product_
-		 * Code, Board_Size, etc.
-		 */
-
-		/* Get pointers to the presumed register locations and save contents */
-
-		sasr_3393 = &(((gvp11_scsiregs *)(ZTWO_VADDR(address)))->SASR);
-		scmd_3393 = &(((gvp11_scsiregs *)(ZTWO_VADDR(address)))->SCMD);
-		save_sasr = *sasr_3393;
-
-		/* First test the AuxStatus Reg */
-
-		q = *sasr_3393;	/* read it */
-		if (q & 0x08)	/* bit 3 should always be clear */
-			goto release;
-		*sasr_3393 = WD_AUXILIARY_STATUS;	/* setup indirect address */
-		if (*sasr_3393 == WD_AUXILIARY_STATUS) {	/* shouldn't retain the write */
-			*sasr_3393 = save_sasr;	/* Oops - restore this byte */
-			goto release;
-		}
-		if (*sasr_3393 != q) {	/* should still read the same */
-			*sasr_3393 = save_sasr;	/* Oops - restore this byte */
-			goto release;
-		}
-		if (*scmd_3393 != q)	/* and so should the image at 0x1f */
-			goto release;
-
-		/*
-		 * Ok, we probably have a wd33c93, but let's check a few other places
-		 * for good measure. Make sure that this works for both 'A and 'B
-		 * chip versions.
-		 */
-
-		*sasr_3393 = WD_SCSI_STATUS;
-		q = *scmd_3393;
-		*sasr_3393 = WD_SCSI_STATUS;
-		*scmd_3393 = ~q;
-		*sasr_3393 = WD_SCSI_STATUS;
-		qq = *scmd_3393;
-		*sasr_3393 = WD_SCSI_STATUS;
-		*scmd_3393 = q;
-		if (qq != q)	/* should be read only */
-			goto release;
-		*sasr_3393 = 0x1e;	/* this register is unimplemented */
-		q = *scmd_3393;
-		*sasr_3393 = 0x1e;
-		*scmd_3393 = ~q;
-		*sasr_3393 = 0x1e;
-		qq = *scmd_3393;
-		*sasr_3393 = 0x1e;
-		*scmd_3393 = q;
-		if (qq != q || qq != 0xff)	/* should be read only, all 1's */
+		regs = (gvp11_scsiregs *)(ZTWO_VADDR(address));
+		if (check_wd33c93(regs))
 			goto release;
-		*sasr_3393 = WD_TIMEOUT_PERIOD;
-		q = *scmd_3393;
-		*sasr_3393 = WD_TIMEOUT_PERIOD;
-		*scmd_3393 = ~q;
-		*sasr_3393 = WD_TIMEOUT_PERIOD;
-		qq = *scmd_3393;
-		*sasr_3393 = WD_TIMEOUT_PERIOD;
-		*scmd_3393 = q;
-		if (qq != (~q & 0xff))	/* should be read/write */
-			goto release;
-#endif
 
 		instance = scsi_register(tpnt, sizeof(struct WD33C93_hostdata));
 		if (instance == NULL)
@@ -311,7 +318,6 @@ int __init gvp11_detect(struct scsi_host_template *tpnt)
 		else
 			hdata->dma_xfer_mask = default_dma_xfer_mask;
 
-		regs = (gvp11_scsiregs *)(instance->base);
 		regs->secret2 = 1;
 		regs->secret1 = 0;
 		regs->secret3 = 15;