aboutsummaryrefslogtreecommitdiffstats
path: root/include
diff options
context:
space:
mode:
authorDaniel Vetter <daniel.vetter@ffwll.ch>2017-10-11 13:22:50 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2017-10-11 13:22:51 +0200
commit7c0f24a4c49c336ba82a429ef2fed0008efa9422 (patch)
tree27900a96ef1fd32151293a6c717b7037fd18baca /include
parent0c17151aaae4f051ebdccde412e912631e450345 (diff)
parent667063acb81931e2f8fd0cb91df9fcccad131d9a (diff)
Merge tag 'regmap-poll-field' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap into drm-misc-next
regmap: Add field polling macro Requested by Maxime Ripard to make sun4i compile again (next time the other way round is better). Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20171004104732.jkps4ufekfizcrkz@sirena.co.uk
Diffstat (limited to 'include')
-rw-r--r--include/linux/regmap.h39
1 files changed, 39 insertions, 0 deletions
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 978abfbac617..93a4663d7acb 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -139,6 +139,45 @@ struct reg_sequence {
pollret ?: ((cond) ? 0 : -ETIMEDOUT); \
})
+/**
+ * regmap_field_read_poll_timeout - Poll until a condition is met or timeout
+ *
+ * @field: Regmap field to read from
+ * @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). Should be less than ~20ms since usleep_range
+ * is used (see Documentation/timers/timers-howto.txt).
+ * @timeout_us: Timeout in us, 0 means never timeout
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout or the regmap_field_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.
+ *
+ * This is modelled after the readx_poll_timeout macros in linux/iopoll.h.
+ */
+#define regmap_field_read_poll_timeout(field, val, cond, sleep_us, timeout_us) \
+({ \
+ ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \
+ int pollret; \
+ might_sleep_if(sleep_us); \
+ for (;;) { \
+ pollret = regmap_field_read((field), &(val)); \
+ if (pollret) \
+ break; \
+ if (cond) \
+ break; \
+ if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \
+ pollret = regmap_field_read((field), &(val)); \
+ break; \
+ } \
+ if (sleep_us) \
+ usleep_range((sleep_us >> 2) + 1, sleep_us); \
+ } \
+ pollret ?: ((cond) ? 0 : -ETIMEDOUT); \
+})
+
#ifdef CONFIG_REGMAP
enum regmap_endian {

Privacy Policy