Commit Graph

6 Commits

Author SHA1 Message Date
Julia Lawall 9c2e5cb38d regmap: constify regmap_bus structures
These regmap_bus structures are only passed as the second argument to
__devm_regmap_init or __regmap_init, both of which are const, so the
regmap_bus structures can be const too.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-08-14 17:36:29 +01:00
Jack Pham dec8e8f6e6 regmap: spmi: Fix regmap_spmi_ext_read in multi-byte case
Specifically for the case of reads that use the Extended Register
Read Long command, a multi-byte read operation is broken up into
8-byte chunks.  However the call to spmi_ext_register_readl() is
incorrectly passing 'val_size', which if greater than 8 will
always fail.  The argument should instead be 'len'.

Fixes: c9afbb05a9 ("regmap: spmi: support base and extended register spaces")
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2016-04-15 10:11:45 +01:00
Nicolas Boichat 1ed8111443 regmap: Move documentation to regmap.h
Init functions defined in regmap*.c files are now prefixed with
__, take lockdep key and class parameters, and should not be
called directly: move the documentation to regmap.h, where the
macros are defined.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-08-11 17:21:44 +01:00
Nicolas Boichat 3cfe7a74d4 regmap: Use different lockdep class for each regmap init call
Lockdep validator complains about recursive locking and deadlock
when two different regmap instances are called in a nested order.
That happens anytime a regmap read/write call needs to access
another regmap.

This is because, for performance reason, lockdep groups all locks
initialized by the same mutex_init() in the same lock class.
Therefore all regmap mutexes are in the same lock class, leading
to lockdep "nested locking" warnings if a regmap accesses another
regmap.

In general, it is impossible to establish in advance the hierarchy
of regmaps, so we make sure that each regmap init call initializes
its own static lock_class_key. This is done by wrapping all
regmap_init calls into macros.

This also allows us to give meaningful names to the lock_class_key.
For example, in rt5677 case, we have in /proc/lockdep_chains:
irq_context: 0
[ffffffc0018d2198] &dev->mutex
[ffffffc0018d2198] &dev->mutex
[ffffffc001bd7f60] rt5677:5104:(&rt5677_regmap)->_lock
[ffffffc001bd7f58] rt5677:5096:(&rt5677_regmap_physical)->_lock
[ffffffc001b95448] &(&base->lock)->rlock

The above would have resulted in a lockdep recursive warning
previously. This is not the case anymore as the lockdep validator
now clearly identifies the 2 regmaps as separate.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-08-07 14:50:59 +01:00
Josh Cartwright c9afbb05a9 regmap: spmi: support base and extended register spaces
SPMI states that a slave may contain two register spaces, the Base
register space is a 5-bit byte-addressable space accessed via the
Register Read/Write and Register Zero Write command sequences, and the
Extended register space: a 16-bit byte-addressable space accessed via
the Extended Read/Write and Extended Read/Write Long command sequences.

Provide support for accessing both of these spaces, taking advantage of
the more bandwidth-efficient commands ('Register 0 Write' vs 'Register
Write', and 'Extended Register Read/Write' vs 'Extended Register
Read/Write Long') when possible.

Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-15 11:55:28 -08:00
Josh Cartwright a01779f89f regmap: add SPMI support
Add basic support for the System Power Management Interface (SPMI) bus.
This is a simple implementation which only implements register accesses
via the Extended Register Read/Write Long commands.

Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-10-28 12:51:43 -07:00