Add bridged amplifiers to cs42l43

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

In some cs42l43 systems a couple of cs35l56 amplifiers are attached
to the cs42l43's SPI and I2S. On Windows the cs42l43 is controlled
by a SDCA class driver and these two amplifiers are controlled by
firmware running on the cs42l43. However, under Linux the decision
was made to interact with the cs42l43 directly, affording the user
greater control over the audio system. However, this has resulted
in an issue where these two bridged cs35l56 amplifiers are not
populated in ACPI and must be added manually. There is at least an
SDCA extension unit DT entry we can key off.

The process of adding this is handled using a software node, firstly the
ability to add native chip selects to software nodes must be added.
Secondly, an additional flag for naming the SPI devices is added this
allows the machine driver to key to the correct amplifier. Then finally,
the cs42l43 SPI driver adds the two amplifiers directly onto its SPI
bus.

An additional series will follow soon to add the audio machine driver
parts (in the sof-sdw driver), however that is fairly orthogonal to
this part of the process, getting the actual amplifiers registered.

1 files changed, 42 insertions, 7 deletions

diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 7e50cbd97f86..0ea7823b7f31 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -22,14 +22,14 @@ extern int do_sys_settimeofday64(const struct timespec64 *tv,
 				 const struct timezone *tz);
 
 /*
- * ktime_get() family: read the current time in a multitude of ways,
+ * ktime_get() family - read the current time in a multitude of ways.
  *
  * The default time reference is CLOCK_MONOTONIC, starting at
  * boot time but not counting the time spent in suspend.
  * For other references, use the functions with "real", "clocktai",
  * "boottime" and "raw" suffixes.
  *
- * To get the time in a different format, use the ones wit
+ * To get the time in a different format, use the ones with
  * "ns", "ts64" and "seconds" suffix.
  *
  * See Documentation/core-api/timekeeping.rst for more details.
@@ -74,6 +74,8 @@ extern u32 ktime_get_resolution_ns(void);
 
 /**
  * ktime_get_real - get the real (wall-) time in ktime_t format
+ *
+ * Returns: real (wall) time in ktime_t format
  */
 static inline ktime_t ktime_get_real(void)
 {
@@ -86,10 +88,12 @@ static inline ktime_t ktime_get_coarse_real(void)
 }
 
 /**
- * ktime_get_boottime - Returns monotonic time since boot in ktime_t format
+ * ktime_get_boottime - Get monotonic time since boot in ktime_t format
  *
  * This is similar to CLOCK_MONTONIC/ktime_get, but also includes the
  * time spent in suspend.
+ *
+ * Returns: monotonic time since boot in ktime_t format
  */
 static inline ktime_t ktime_get_boottime(void)
 {
@@ -102,7 +106,9 @@ static inline ktime_t ktime_get_coarse_boottime(void)
 }
 
 /**
- * ktime_get_clocktai - Returns the TAI time of day in ktime_t format
+ * ktime_get_clocktai - Get the TAI time of day in ktime_t format
+ *
+ * Returns: the TAI time of day in ktime_t format
  */
 static inline ktime_t ktime_get_clocktai(void)
 {
@@ -144,32 +150,60 @@ static inline u64 ktime_get_coarse_clocktai_ns(void)
 
 /**
  * ktime_mono_to_real - Convert monotonic time to clock realtime
+ * @mono: monotonic time to convert
+ *
+ * Returns: time converted to realtime clock
  */
 static inline ktime_t ktime_mono_to_real(ktime_t mono)
 {
 	return ktime_mono_to_any(mono, TK_OFFS_REAL);
 }
 
+/**
+ * ktime_get_ns - Get the current time in nanoseconds
+ *
+ * Returns: current time converted to nanoseconds
+ */
 static inline u64 ktime_get_ns(void)
 {
 	return ktime_to_ns(ktime_get());
 }
 
+/**
+ * ktime_get_real_ns - Get the current real/wall time in nanoseconds
+ *
+ * Returns: current real time converted to nanoseconds
+ */
 static inline u64 ktime_get_real_ns(void)
 {
 	return ktime_to_ns(ktime_get_real());
 }
 
+/**
+ * ktime_get_boottime_ns - Get the monotonic time since boot in nanoseconds
+ *
+ * Returns: current boottime converted to nanoseconds
+ */
 static inline u64 ktime_get_boottime_ns(void)
 {
 	return ktime_to_ns(ktime_get_boottime());
 }
 
+/**
+ * ktime_get_clocktai_ns - Get the current TAI time of day in nanoseconds
+ *
+ * Returns: current TAI time converted to nanoseconds
+ */
 static inline u64 ktime_get_clocktai_ns(void)
 {
 	return ktime_to_ns(ktime_get_clocktai());
 }
 
+/**
+ * ktime_get_raw_ns - Get the raw monotonic time in nanoseconds
+ *
+ * Returns: current raw monotonic time converted to nanoseconds
+ */
 static inline u64 ktime_get_raw_ns(void)
 {
 	return ktime_to_ns(ktime_get_raw());
@@ -224,8 +258,8 @@ extern bool timekeeping_rtc_skipresume(void);
 
 extern void timekeeping_inject_sleeptime64(const struct timespec64 *delta);
 
-/*
- * struct ktime_timestanps - Simultaneous mono/boot/real timestamps
+/**
+ * struct ktime_timestamps - Simultaneous mono/boot/real timestamps
  * @mono:	Monotonic timestamp
  * @boot:	Boottime timestamp
  * @real:	Realtime timestamp
@@ -242,7 +276,8 @@ struct ktime_timestamps {
  * @cycles:	Clocksource counter value to produce the system times
  * @real:	Realtime system time
  * @raw:	Monotonic raw system time
- * @clock_was_set_seq:	The sequence number of clock was set events
+ * @cs_id:	Clocksource ID
+ * @clock_was_set_seq:	The sequence number of clock-was-set events
  * @cs_was_changed_seq:	The sequence number of clocksource change events
  */
 struct system_time_snapshot {