ASoC: cs35l56: Fixes to handling of ASP1 config

Merge series from Richard Fitzgerald <rf@opensource.cirrus.com>:

This chain fixes some problems with some previous patches for handling
the ASP1 config registers. The root of the problem is that the ownership
of these registers can be either with the firmware or the driver, and that
the chip has to be soft-reset after downloading the firmware.

This chain adds and uses a regmap_read_bypassed() function so that the
driver can leave the regmap in cache-only until the chip has rebooted,
but still poll a register to detect when the chip has rebooted.

Richard Fitzgerald (4):
  regmap: Add regmap_read_bypassed()
  ALSA: hda: cs35l56: Exit cache-only after
    cs35l56_wait_for_firmware_boot()
  ASoC: cs35l56: Fix unintended bus access while resetting amp
  ASoC: cs35l56: Prevent overwriting firmware ASP config

 drivers/base/regmap/regmap.c      | 37 ++++++++++++++
 include/linux/regmap.h            |  8 +++
 include/sound/cs35l56.h           |  2 +
 sound/pci/hda/cs35l56_hda.c       |  4 ++
 sound/soc/codecs/cs35l56-sdw.c    |  2 -
 sound/soc/codecs/cs35l56-shared.c | 83 ++++++++++++++++++++-----------
 sound/soc/codecs/cs35l56.c        | 26 +++++++++-
 7 files changed, 130 insertions(+), 32 deletions(-)

--
2.39.2

1 files changed, 37 insertions, 0 deletions

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 5cb425f6f02d..0a34dd3c4f38 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -2839,6 +2839,43 @@ int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
 EXPORT_SYMBOL_GPL(regmap_read);
 
 /**
+ * regmap_read_bypassed() - Read a value from a single register direct
+ *			    from the device, bypassing the cache
+ *
+ * @map: Register map to read from
+ * @reg: Register to be read from
+ * @val: Pointer to store read value
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_read_bypassed(struct regmap *map, unsigned int reg, unsigned int *val)
+{
+	int ret;
+	bool bypass, cache_only;
+
+	if (!IS_ALIGNED(reg, map->reg_stride))
+		return -EINVAL;
+
+	map->lock(map->lock_arg);
+
+	bypass = map->cache_bypass;
+	cache_only = map->cache_only;
+	map->cache_bypass = true;
+	map->cache_only = false;
+
+	ret = _regmap_read(map, reg, val);
+
+	map->cache_bypass = bypass;
+	map->cache_only = cache_only;
+
+	map->unlock(map->lock_arg);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_read_bypassed);
+
+/**
  * regmap_raw_read() - Read raw data from the device
  *
  * @map: Register map to read from