[PATCH 06/13 v2] soc: ixp4xx: Add features from regmap helper

[Linus Walleij]

If we want to read the CFG2 register on the expansion bus and
apply the inversion and check for some hardcoded versions this
helper comes in handy.

Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
ChangeLog v1->v2:
- No changes.
---
 include/linux/soc/ixp4xx/cpu.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/include/linux/soc/ixp4xx/cpu.h b/include/linux/soc/ixp4xx/cpu.h
index 88bd8de0e803..48c2e241ac83 100644
--- a/include/linux/soc/ixp4xx/cpu.h
+++ b/include/linux/soc/ixp4xx/cpu.h
@@ -9,6 +9,7 @@
 #define __SOC_IXP4XX_CPU_H__
 
 #include <linux/io.h>
+#include <linux/regmap.h>
 #ifdef CONFIG_ARM
 #include <asm/cputype.h>
 #endif
@@ -23,6 +24,9 @@
 #define IXP46X_PROCESSOR_ID_VALUE	0x69054200 /* including IXP455 */
 #define IXP46X_PROCESSOR_ID_MASK	0xfffffff0
 
+/* Feature register in the expansion bus controller */
+#define IXP4XX_EXP_CNFG2		0x2c
+
 /* "fuse" bits of IXP_EXP_CFG2 */
 /* All IXP4xx CPUs */
 #define IXP4XX_FEATURE_RCOMP		(1 << 0)
@@ -89,6 +93,22 @@
 
 u32 ixp4xx_read_feature_bits(void);
 void ixp4xx_write_feature_bits(u32 value);
+static inline u32 cpu_ixp4xx_features(struct regmap *rmap)
+{
+	u32 val;
+
+	regmap_read(rmap, IXP4XX_EXP_CNFG2, &val);
+	/* For some reason this register is inverted */
+	val = ~val;
+	if (cpu_is_ixp42x_rev_a0())
+		return IXP42X_FEATURE_MASK & ~(IXP4XX_FEATURE_RCOMP |
+					       IXP4XX_FEATURE_AES);
+	if (cpu_is_ixp42x())
+		return val & IXP42X_FEATURE_MASK;
+	if (cpu_is_ixp43x())
+		return val & IXP43X_FEATURE_MASK;
+	return val & IXP46X_FEATURE_MASK;
+}
 #else
 #define cpu_is_ixp42x_rev_a0()		0
 #define cpu_is_ixp42x()			0
@@ -101,6 +121,10 @@ static inline u32 ixp4xx_read_feature_bits(void)
 static inline void ixp4xx_write_feature_bits(u32 value)
 {
 }
+static inline u32 cpu_ixp4xx_features(struct regmap *rmap)
+{
+	return 0;
+}
 #endif
 
 #endif  /* _ASM_ARCH_CPU_H */
-- 
2.34.1