Add an API to continuously read a register until a condition is satisfied or a timeout occurs.
Signed-off-by: Faiz Abbas faiz_abbas@ti.com --- include/regmap.h | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+)
diff --git a/include/regmap.h b/include/regmap.h index 3cd97d3b94..dfc3a4f231 100644 --- a/include/regmap.h +++ b/include/regmap.h @@ -299,4 +299,38 @@ void *regmap_get_range(struct regmap *map, unsigned int range_num); */ int regmap_uninit(struct regmap *map);
+/** + * 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) + * @timeout_us: Timeout in us, 0 means never timeout + * + * 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. + * + * Modelled after readx_poll_timeout macro in linux/iopoll.h + */ + +#define regmap_read_poll_timeout(map, addr, val, cond, timeout_us) \ +({ \ + unsigned long timeout = timer_get_us() + timeout_us; \ + int pollret; \ + for (;;) { \ + pollret = regmap_read((map), (addr), &(val)); \ + if (pollret) \ + break; \ + if (cond) \ + break; \ + if (timeout_us && time_after(timer_get_us(), timeout)) { \ + pollret = regmap_read((map), (addr), &(val)); \ + break; \ + } \ + } \ + pollret ?: ((cond) ? 0 : -ETIMEDOUT); \ +}) + #endif