use new E4000 tuner driver, allow manual gain

Many thanks to Hoernchen for making the driver work properly
and adding manual gain!

Signed-off-by: Steve Markgraf <steve@steve-m.de>

include/reg_field.h

@@ -0,0 +1,60 @@
+#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