[PATCHv2] [ARM] orion5x: use safer FPGA ID 'default' for TS-78xx

[alex@digriz.org.uk (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).

Changelog:
 v2: neater implementation and some cosmetic changes
 v1: initial release <20110305112937.GA22117@chipmunk>

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
---
 arch/arm/mach-orion5x/ts78xx-fpga.h  |   19 ++++++++++---------
 arch/arm/mach-orion5x/ts78xx-setup.c |   19 ++++++++++++++-----
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/arch/arm/mach-orion5x/ts78xx-fpga.h b/arch/arm/mach-orion5x/ts78xx-fpga.h
index 791f754..151e89e 100644
--- a/arch/arm/mach-orion5x/ts78xx-fpga.h
+++ b/arch/arm/mach-orion5x/ts78xx-fpga.h
@@ -1,3 +1,4 @@
+#define TS7800_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(TS7800_FPGA_MAGIC, 0x01),
+	TS7800_REV_2	= FPGAID(TS7800_FPGA_MAGIC, 0x02),
+	TS7800_REV_3	= FPGAID(TS7800_FPGA_MAGIC, 0x03),
+	TS7800_REV_4	= FPGAID(TS7800_FPGA_MAGIC, 0x04),
+	TS7800_REV_5	= FPGAID(TS7800_FPGA_MAGIC, 0x05),
+	TS7800_REV_6	= FPGAID(TS7800_FPGA_MAGIC, 0x06),
+	TS7800_REV_7	= FPGAID(TS7800_FPGA_MAGIC, 0x07),
+	TS7800_REV_8	= FPGAID(TS7800_FPGA_MAGIC, 0x08),
+	TS7800_REV_9	= FPGAID(TS7800_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..3f2e1cd 100644
--- a/arch/arm/mach-orion5x/ts78xx-setup.c
+++ b/arch/arm/mach-orion5x/ts78xx-setup.c
@@ -399,11 +399,20 @@ 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 devices if magic matches */
+		switch ((ts78xx_fpga.id >> 8) & 0xffffff) {
+		case TS7800_FPGA_MAGIC:
+			printk(KERN_WARNING "TS-7800 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;
+		default:
+			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