#ifndef _REG_FIELD_H
  #define _REG_FIELD_H
  
  #include <stdint.h>
  #include <stdarg.h>
  
  enum cmd_op {
  	CMD_OP_GET	= (1 << 0),
  	CMD_OP_SET	= (1 << 1),
  	CMD_OP_EXEC	= (1 << 2),
  };
  
  enum pstate {
  	ST_IN_CMD,
  	ST_IN_ARG,
  };
  
  struct strbuf {
  	uint8_t idx;
  	char buf[32];
  };
  
  struct cmd_state {
  	struct strbuf cmd;
  	struct strbuf arg;
  	enum pstate state;
  	void (*out)(const char *format, va_list ap);
  };
  
  struct cmd {
  	const char *cmd;
  	uint32_t ops;
  	int (*cb)(struct cmd_state *cs, enum cmd_op op, const char *cmd,
  		  int argc, char **argv);
  	const char *help;
  };
  
  /* structure describing a field in a register */
  struct reg_field {
  	uint8_t reg;
  	uint8_t shift;
  	uint8_t width;
  };
  
  struct reg_field_ops {
  	const struct reg_field *fields;
  	const char **field_names;
  	uint32_t num_fields;
  	void *data;
  	int (*write_cb)(void *data, uint32_t reg, uint32_t val);
  	uint32_t (*read_cb)(void *data, uint32_t reg);
  };
  
  uint32_t reg_field_read(struct reg_field_ops *ops, struct reg_field *field);
  int reg_field_write(struct reg_field_ops *ops, struct reg_field *field, uint32_t val);
  int reg_field_cmd(struct cmd_state *cs, enum cmd_op op,
  		  const char *cmd, int argc, char **argv,
  		  struct reg_field_ops *ops);
  
  #endif