wait_bit: add 8/16/32 BE/LE versions of wait_for_bit

Add 8/16/32 bits and BE/LE versions of wait_for_bit.
This is needed for reading registers that are not aligned to 32 bits, and for
Big Endian platforms.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>

include/wait_bit.h

@@ -69,5 +69,70 @@ static inline int wait_for_bit(const char *prefix, const u32 *reg,
 	return -ETIMEDOUT;
 }
 
+/**
+ * wait_for_bit_x()	waits for bit set/cleared in register
+ *
+ * Function polls register waiting for specific bit(s) change
+ * (either 0->1 or 1->0). It can fail under two conditions:
+ * - Timeout
+ * - User interaction (CTRL-C)
+ * Function succeeds only if all bits of masked register are set/cleared
+ * (depending on set option).
+ *
+ * @param reg		Register that will be read (using read_x())
+ * @param mask		Bit(s) of register that must be active
+ * @param set		Selects wait condition (bit set or clear)
+ * @param timeout_ms	Timeout (in milliseconds)
+ * @param breakable	Enables CTRL-C interruption
+ * @return		0 on success, -ETIMEDOUT or -EINTR on failure
+ */
+
+#define BUILD_WAIT_FOR_BIT(sfx, type, read)				\
+									\
+static inline int wait_for_bit_##sfx(const void *reg,			\
+				     const type mask,			\
+				     const bool set,			\
+				     const unsigned int timeout_ms,	\
+				     const bool breakable)		\
+{									\
+	type val;							\
+	unsigned long start = get_timer(0);				\
+									\
+	while (1) {							\
+		val = read(reg);					\
+									\
+		if (!set)						\
+			val = ~val;					\
+									\
+		if ((val & mask) == mask)				\
+			return 0;					\
+									\
+		if (get_timer(start) > timeout_ms)			\
+			break;						\
+									\
+		if (breakable && ctrlc()) {				\
+			puts("Abort\n");				\
+			return -EINTR;					\
+		}							\
+									\
+		udelay(1);						\
+		WATCHDOG_RESET();					\
+	}								\
+									\
+	debug("%s: Timeout (reg=%p mask=%x wait_set=%i)\n", __func__,	\
+	      reg, mask, set);						\
+									\
+	return -ETIMEDOUT;						\
+}
+
+BUILD_WAIT_FOR_BIT(8, u8, readb)
+BUILD_WAIT_FOR_BIT(le16, u16, readw)
+#ifdef readw_be
+BUILD_WAIT_FOR_BIT(be16, u16, readw_be)
+#endif
+BUILD_WAIT_FOR_BIT(le32, u32, readl)
+#ifdef readl_be
+BUILD_WAIT_FOR_BIT(be32, u32, readl_be)
+#endif
 
 #endif