include/linux/regmap.h

Source file repositories/reference/linux-study-clean/include/linux/regmap.h

File Facts

System
Linux kernel
Corpus path
include/linux/regmap.h
Extension
.h
Size
76478 bytes
Lines
2166
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct reg_default {
	unsigned int reg;
	unsigned int def;
};

/**
 * struct reg_sequence - An individual write from a sequence of writes.
 *
 * @reg: Register address.
 * @def: Register value.
 * @delay_us: Delay to be applied after the register write in microseconds
 *
 * Register/value pairs for sequences of writes with an optional delay in
 * microseconds to be applied after each write.
 */
struct reg_sequence {
	unsigned int reg;
	unsigned int def;
	unsigned int delay_us;
};

#define REG_SEQ(_reg, _def, _delay_us) {		\
				.reg = _reg,		\
				.def = _def,		\
				.delay_us = _delay_us,	\
				}
#define REG_SEQ0(_reg, _def)	REG_SEQ(_reg, _def, 0)

/**
 * regmap_read_poll_timeout - Poll until a condition is met or a timeout occurs
 *
 * @map: Regmap to read from
 * @addr: Address to poll
 * @val: Unsigned integer variable to read the value into
 * @cond: Break condition (usually involving @val)
 * @sleep_us: Maximum time to sleep between reads in us (0 tight-loops). Please
 *            read usleep_range() function description for details and
 *            limitations.
 * @timeout_us: Timeout in us, 0 means never timeout
 *
 * This is modelled after the readx_poll_timeout macros in linux/iopoll.h.
 *
 * Returns: 0 on success and -ETIMEDOUT upon a timeout or the regmap_read
 * error return value in case of a error read. In the two former cases,
 * the last read value at @addr is stored in @val. Must not be called
 * from atomic context if sleep_us or timeout_us are used.
 */
#define regmap_read_poll_timeout(map, addr, val, cond, sleep_us, timeout_us) \
({ \
	int __ret, __tmp; \
	__tmp = read_poll_timeout(regmap_read, __ret, __ret || (cond), \
			sleep_us, timeout_us, false, (map), (addr), &(val)); \
	__ret ?: __tmp; \
})

/**
 * regmap_read_poll_timeout_atomic - Poll until a condition is met or a timeout occurs
 *
 * @map: Regmap to read from
 * @addr: Address to poll
 * @val: Unsigned integer variable to read the value into
 * @cond: Break condition (usually involving @val)
 * @delay_us: Time to udelay between reads in us (0 tight-loops). Please
 *            read udelay() function description for details and
 *            limitations.
 * @timeout_us: Timeout in us, 0 means never timeout
 *
 * This is modelled after the readx_poll_timeout_atomic macros in linux/iopoll.h.
 *
 * Note: In general regmap cannot be used in atomic context. If you want to use
 * this macro then first setup your regmap for atomic use (flat or no cache
 * and MMIO regmap).
 *
 * Returns: 0 on success and -ETIMEDOUT upon a timeout or the regmap_read
 * error return value in case of a error read. In the two former cases,
 * the last read value at @addr is stored in @val.
 */
#define regmap_read_poll_timeout_atomic(map, addr, val, cond, delay_us, timeout_us) \
({ \
	u64 __timeout_us = (timeout_us); \
	unsigned long __delay_us = (delay_us); \
	ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
	int __ret; \
	for (;;) { \
		__ret = regmap_read((map), (addr), &(val)); \
		if (__ret) \
			break; \
		if (cond) \
			break; \
		if ((__timeout_us) && \

Annotation

Implementation Notes