| Message ID | 20170929082306.16193-10-wens@csie.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Wed, Oct 04, 2017 at 11:47:32AM +0100, Mark Brown wrote: > On Fri, Sep 29, 2017 at 04:23:01PM +0800, Chen-Yu Tsai wrote: > > This patch adds a macro regmap_field_read_poll_timeout that works > > similar to the readx_poll_timeout defined in linux/iopoll.h, except > > that this can also return the error value returned by a failed > > regmap_field_read. > > The following changes since commit 2bd6bf03f4c1c59381d62c61d03f6cc3fe71f66e: > > Linux 4.14-rc1 (2017-09-16 15:47:51 -0700) > > are available in the git repository at: > > git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git tags/regmap-poll-field > > for you to fetch changes up to 667063acb81931e2f8fd0cb91df9fcccad131d9a: > > regmap: add iopoll-like polling macro for regmap_field (2017-10-04 11:46:32 +0100) Pulled into drm-misc-next for 4.15 since Maxime needs that for the sun4i changes. Thanks, Daniel > > ---------------------------------------------------------------- > regmap: Add field polling macro > > ---------------------------------------------------------------- > Chen-Yu Tsai (1): > regmap: add iopoll-like polling macro for regmap_field > > include/linux/regmap.h | 39 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
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 {
This patch adds a macro regmap_field_read_poll_timeout that works similar to the readx_poll_timeout defined in linux/iopoll.h, except that this can also return the error value returned by a failed regmap_field_read. Signed-off-by: Chen-Yu Tsai <wens@csie.org> --- include/linux/regmap.h | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+)