Subject: cell: introduce unions for some special registers found in pervasive area

The pervasive area contains some registers, which contain a byte for each spe.
Another register contains upper half for ppe and lower half for spe.
This patch adds unions, to access either the spe or ppe value easily.

Signed-off-by: Christian Krafft <krafft@de.ibm.com>

Index: linux-2.6/arch/powerpc/platforms/cell/cbe_regs.h
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/cbe_regs.h
+++ linux-2.6/arch/powerpc/platforms/cell/cbe_regs.h
@@ -141,6 +141,20 @@ struct ext_tr_timer {
 	};
 };
 
+union spe_reg {
+	u64 val;
+	u8 spe[8];
+};
+
+union ppe_spe_reg {
+	u64 val;
+	struct {
+		u32 ppe;
+		u32 spe;
+	};
+};
+
+
 struct cbe_pmd_regs {
 	/* Trace Logic Analyzer */
 	u64	pad_0x0000;					/* 0x0000 */
@@ -172,22 +186,22 @@ struct cbe_pmd_regs {
 	u8	pad_0x0480_0x0800 [0x0800 - 0x0480];		/* 0x0480 */
 
 	/* Thermal Sensor Registers */
-	u64	ts_ctsr1;					/* 0x0800 */
+	union	spe_reg	ts_ctsr1;				/* 0x0800 */
 	u64	ts_ctsr2;					/* 0x0808 */
-	u64	ts_mtsr1;					/* 0x0810 */
+	union	spe_reg	ts_mtsr1;				/* 0x0810 */
 	u64	ts_mtsr2;					/* 0x0818 */
-	u64	ts_itr1;					/* 0x0820 */
+	union	spe_reg	ts_itr1;				/* 0x0820 */
 	u64	ts_itr2;					/* 0x0828 */
 	u64	ts_gitr;					/* 0x0830 */
 	u64	ts_isr;						/* 0x0838 */
 	u64	ts_imr;						/* 0x0840 */
-	u64	tm_cr1;						/* 0x0848 */
+	union	spe_reg	tm_cr1;					/* 0x0848 */
 	u64	tm_cr2;						/* 0x0850 */
 	u64	tm_simr;					/* 0x0858 */
-	u64	tm_tpr;						/* 0x0860 */
-	u64	tm_str1;					/* 0x0868 */
+	union	ppe_spe_reg tm_tpr;				/* 0x0860 */
+	union	spe_reg	tm_str1;				/* 0x0868 */
 	u64	tm_str2;					/* 0x0870 */
-	u64	tm_tsr;						/* 0x0878 */
+	union	ppe_spe_reg tm_tsr;				/* 0x0878 */
 
 	/* Power Management */
 	u64	pmcr;						/* 0x0880 */
Index: linux-2.6/arch/powerpc/platforms/cell/cbe_thermal.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/cbe_thermal.c
+++ linux-2.6/arch/powerpc/platforms/cell/cbe_thermal.c
@@ -30,22 +30,53 @@
 
 #include "cbe_regs.h"
 
-static ssize_t spu_show_temp(struct sys_device *sysdev, char *buf)
+static struct cbe_pmd_regs *get_pmd_regs(struct sys_device *sysdev)
+{
+	struct spu *spu;
+
+	spu = container_of(sysdev, struct spu, sysdev);
+
+	return cbe_get_pmd_regs(spu->devnode);
+}
+/* returns the value for a given spu in a given register */
+static u8 spu_read_register_value(struct sys_device *sysdev, union spe_reg *reg)
 {
-	struct spu *spu = container_of(sysdev, struct spu, sysdev);
-	struct cbe_pmd_regs *pmd_regs;
-	struct device_node *devnode;
-	u64 value;
 	unsigned int *id;
+	union spe_reg value;
+	struct spu *spu;
+
+	spu = container_of(sysdev, struct spu, sysdev);
+	id = (unsigned int *)get_property(spu->devnode, "reg", NULL);
+	value.val = in_be64(&reg->val);
 
-	devnode = spu->devnode;
-	pmd_regs = cbe_get_pmd_regs(devnode);
-	value = in_be64(&pmd_regs->ts_ctsr1);
+	return value.spe[*id];
+}
 
+/* writes the value for a given spu in a given register */
+static void spu_write_register_value(struct sys_device *sysdev, union spe_reg *reg, u8 new_value)
+{
+	unsigned int *id;
+	union spe_reg value;
+	struct spu *spu;
+
+	spu = container_of(sysdev, struct spu, sysdev);
 	id = (unsigned int *)get_property(spu->devnode, "reg", NULL);
 
-	/* access the corresponding byte */
-	value >>= ((*id)*8);
+	value.val = in_be64(&reg->val);
+	value.spe[*id] = new_value;
+
+	out_be64(&reg->val, value.val);
+}
+
+
+static ssize_t spu_show_temp(struct sys_device *sysdev, char *buf)
+{
+	int value;
+	struct cbe_pmd_regs *pmd_regs;
+
+	pmd_regs = get_pmd_regs(sysdev);
+
+	value = spu_read_register_value(sysdev, &pmd_regs->ts_ctsr1);
 	/* clear all other bits */
 	value &= 0x3F;
 	/* temp is stored in steps of 2 degrees */