[PATCH] [ARM] orion5x: use safer FPGA ID 'default' for TS-78xx

[Alexander Clouter]

Originally the FPGA ID checking switch statement left disabled all the
TS implemented FPGA devices if the ID was unknown to it.  Michael Spang
created a fix in 3c390473 that changed the default to enable the devices
in the event TS silently release more revisions into the wild, this
unfortunately breaks custom FPGA bitstreams.

This patch amends the switch statement so that the TS devices are only
enabled if on the revision number is unknown (whilst the magic matches).

Signed-off-by: Alexander Clouter <alex at digriz.org.uk>
---
 arch/arm/mach-orion5x/ts78xx-fpga.h  |   19 ++++++++++---------
 arch/arm/mach-orion5x/ts78xx-setup.c |   18 +++++++++++++-----
 2 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/arch/arm/mach-orion5x/ts78xx-fpga.h b/arch/arm/mach-orion5x/ts78xx-fpga.h
index 791f754..f0e3be1 100644
--- a/arch/arm/mach-orion5x/ts78xx-fpga.h
+++ b/arch/arm/mach-orion5x/ts78xx-fpga.h
@@ -1,3 +1,4 @@
+#define TS_78XX_FPGA_MAGIC 0x00b480
 #define FPGAID(_magic, _rev) ((_magic << 8) + _rev)
 
 /*
@@ -6,15 +7,15 @@
  */
 enum fpga_ids {
 	/* Technologic Systems */
-	TS7800_REV_1	= FPGAID(0x00b480, 0x01),
-	TS7800_REV_2	= FPGAID(0x00b480, 0x02),
-	TS7800_REV_3	= FPGAID(0x00b480, 0x03),
-	TS7800_REV_4	= FPGAID(0x00b480, 0x04),
-	TS7800_REV_5	= FPGAID(0x00b480, 0x05),
-	TS7800_REV_6	= FPGAID(0x00b480, 0x06),
-	TS7800_REV_7	= FPGAID(0x00b480, 0x07),
-	TS7800_REV_8	= FPGAID(0x00b480, 0x08),
-	TS7800_REV_9	= FPGAID(0x00b480, 0x09),
+	TS7800_REV_1	= FPGAID(TS_78XX_FPGA_MAGIC, 0x01),
+	TS7800_REV_2	= FPGAID(TS_78XX_FPGA_MAGIC, 0x02),
+	TS7800_REV_3	= FPGAID(TS_78XX_FPGA_MAGIC, 0x03),
+	TS7800_REV_4	= FPGAID(TS_78XX_FPGA_MAGIC, 0x04),
+	TS7800_REV_5	= FPGAID(TS_78XX_FPGA_MAGIC, 0x05),
+	TS7800_REV_6	= FPGAID(TS_78XX_FPGA_MAGIC, 0x06),
+	TS7800_REV_7	= FPGAID(TS_78XX_FPGA_MAGIC, 0x07),
+	TS7800_REV_8	= FPGAID(TS_78XX_FPGA_MAGIC, 0x08),
+	TS7800_REV_9	= FPGAID(TS_78XX_FPGA_MAGIC, 0x09),
 
 	/* Unaffordable & Expensive */
 	UAE_DUMMY	= FPGAID(0xffffff, 0x01),
diff --git a/arch/arm/mach-orion5x/ts78xx-setup.c b/arch/arm/mach-orion5x/ts78xx-setup.c
index 1cac714..82e57a6 100644
--- a/arch/arm/mach-orion5x/ts78xx-setup.c
+++ b/arch/arm/mach-orion5x/ts78xx-setup.c
@@ -399,11 +399,19 @@ static void ts78xx_fpga_supports(void)
 		ts78xx_fpga.supports.ts_rng.present = 1;
 		break;
 	default:
-		printk(KERN_WARNING "Unrecognized TS-78XX FPGA ID 0x%02x",
-		       ts78xx_fpga.id);
-		ts78xx_fpga.supports.ts_rtc.present = 1;
-		ts78xx_fpga.supports.ts_nand.present = 1;
-		ts78xx_fpga.supports.ts_rng.present = 1;
+		/* enable TS devices if at least the magic matches */
+		if (((ts78xx_fpga.id >> 8) & 0xffffff) == TS_78XX_FPGA_MAGIC) {
+			printk(KERN_WARNING "TS-78xx FPGA: unrecognized revision 0x%.2x\n",
+					ts78xx_fpga.id & 0xff);
+			ts78xx_fpga.supports.ts_rtc.present = 1;
+			ts78xx_fpga.supports.ts_nand.present = 1;
+			ts78xx_fpga.supports.ts_rng.present = 1;
+			break;
+		}
+
+		ts78xx_fpga.supports.ts_rtc.present = 0;
+		ts78xx_fpga.supports.ts_nand.present = 0;
+		ts78xx_fpga.supports.ts_rng.present = 0;
 	}
 }
 
-- 
1.7.4.1