Expand SoundWire MBQ register map support

Merge series from Charles Keepax <ckeepax@opensource.cirrus.com>:

The current SDCA MBQ (Multi-Byte Quantities) register map only
supports 16-bit types, add support for more sizes and then update
the rt722 driver to use the new support. We also add support for
the deferring feature of MBQs to allow hardware to indicate it is
not currently ready to service a read/write.

Afraid I don't have hardware to test the rt722 change so it is
only build tested, but I thought it good to include a change to
demonstrate the new features in use.

1 files changed, 60 insertions, 2 deletions

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 3871c74f7677..3a96d068915f 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -506,6 +506,32 @@ struct regmap_range_cfg {
 	unsigned int window_len;
 };
 
+/**
+ * struct regmap_sdw_mbq_cfg - Configuration for Multi-Byte Quantities
+ *
+ * @mbq_size: Callback returning the actual size of the given register.
+ * @deferrable: Callback returning true if the hardware can defer
+ *              transactions to the given register. Deferral should
+ *              only be used by SDCA parts and typically which controls
+ *              are deferrable will be specified in either as a hard
+ *              coded list or from the DisCo tables in the platform
+ *              firmware.
+ *
+ * @timeout_us: The time in microseconds after which waiting for a deferred
+ *              transaction should time out.
+ * @retry_us: The time in microseconds between polls of the function busy
+ *            status whilst waiting for an opportunity to retry a deferred
+ *            transaction.
+ *
+ * Provides additional configuration required for SoundWire MBQ register maps.
+ */
+struct regmap_sdw_mbq_cfg {
+	int (*mbq_size)(struct device *dev, unsigned int reg);
+	bool (*deferrable)(struct device *dev, unsigned int reg);
+	unsigned long timeout_us;
+	unsigned long retry_us;
+};
+
 struct regmap_async;
 
 typedef int (*regmap_hw_write)(void *context, const void *data,
@@ -652,6 +678,7 @@ struct regmap *__regmap_init_sdw(struct sdw_slave *sdw,
 				 const char *lock_name);
 struct regmap *__regmap_init_sdw_mbq(struct sdw_slave *sdw,
 				     const struct regmap_config *config,
+				     const struct regmap_sdw_mbq_cfg *mbq_config,
 				     struct lock_class_key *lock_key,
 				     const char *lock_name);
 struct regmap *__regmap_init_spi_avmm(struct spi_device *spi,
@@ -713,6 +740,7 @@ struct regmap *__devm_regmap_init_sdw(struct sdw_slave *sdw,
 				 const char *lock_name);
 struct regmap *__devm_regmap_init_sdw_mbq(struct sdw_slave *sdw,
 					  const struct regmap_config *config,
+					  const struct regmap_sdw_mbq_cfg *mbq_config,
 					  struct lock_class_key *lock_key,
 					  const char *lock_name);
 struct regmap *__devm_regmap_init_slimbus(struct slim_device *slimbus,
@@ -942,7 +970,22 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg);
  */
 #define regmap_init_sdw_mbq(sdw, config)					\
 	__regmap_lockdep_wrapper(__regmap_init_sdw_mbq, #config,		\
-				sdw, config)
+				sdw, config, NULL)
+
+/**
+ * regmap_init_sdw_mbq_cfg() - Initialise MBQ SDW register map with config
+ *
+ * @sdw: Device that will be interacted with
+ * @config: Configuration for register map
+ * @mbq_config: Properties for the MBQ registers
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer
+ * to a struct regmap. The regmap will be automatically freed by the
+ * device management code.
+ */
+#define regmap_init_sdw_mbq_cfg(sdw, config, mbq_config)		\
+	__regmap_lockdep_wrapper(__regmap_init_sdw_mbq, #config,	\
+				sdw, config, mbq_config)
 
 /**
  * regmap_init_spi_avmm() - Initialize register map for Intel SPI Slave
@@ -1155,7 +1198,22 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg);
  */
 #define devm_regmap_init_sdw_mbq(sdw, config)			\
 	__regmap_lockdep_wrapper(__devm_regmap_init_sdw_mbq, #config,   \
-				sdw, config)
+				sdw, config, NULL)
+
+/**
+ * devm_regmap_init_sdw_mbq_cfg() - Initialise managed MBQ SDW register map with config
+ *
+ * @sdw: Device that will be interacted with
+ * @config: Configuration for register map
+ * @mbq_config: Properties for the MBQ registers
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer
+ * to a struct regmap. The regmap will be automatically freed by the
+ * device management code.
+ */
+#define devm_regmap_init_sdw_mbq_cfg(sdw, config, mbq_config)	\
+	__regmap_lockdep_wrapper(__devm_regmap_init_sdw_mbq,	\
+				#config, sdw, config, mbq_config)
 
 /**
  * devm_regmap_init_slimbus() - Initialise managed register map