tools/pbstate: Add clear/set API for board regs

This commits adds a clear/set function that takes a clear and set mask.
This may be useful in situations where only modification if specific
bits is desired.

It might be dangerous to first call the read_board_reg function, perform
modifciations and then call the set_board_reg function since another
process might have done modifications to the register. The
clear_set_board_reg function will acquire the lock read/modify/write and
then release the lock.

tools/pbstate/src/pbstate.c

@@ -490,3 +490,19 @@ int pbstate_write_board_reg(unsigned int index, uint32_t value)
 
     return close_and_save_state(fd, true);
 }
+
+int pbstate_clear_set_board_reg(unsigned int index, uint32_t clear, uint32_t set)
+{
+    if (index > (PB_STATE_NO_OF_BOARD_REGS - 1))
+        return -EINVAL;
+
+    int fd = open_and_load_state(true);
+
+    if (fd < 0)
+        return fd;
+
+    state.board_regs[PB_STATE_NO_OF_BOARD_REGS - index - 1] &= ~clear;
+    state.board_regs[PB_STATE_NO_OF_BOARD_REGS - index - 1] |= set;
+
+    return close_and_save_state(fd, true);
+}

tools/pbstate/src/pbstate.h

@@ -132,6 +132,18 @@ int pbstate_read_board_reg(unsigned int index, uint32_t *value);
  */
 int pbstate_write_board_reg(unsigned int index, uint32_t value);
 
+/**
+ * Clear/set board register bits
+ *
+ * @param[in] index Board register index
+ * @param[in] clear Bits to clear
+ * @param[in] set Bits to set
+ *
+ * @return 0 on success
+ *    -EINVAL on invalid index
+ */
+int pbstate_clear_set_board_reg(unsigned int index, uint32_t clear, uint32_t set);
+
 #ifdef __cplusplus
 }
 #endif