ASoC: wm8904: Add DMIC and DRC support

Merge series from Francesco Dolcini <francesco@dolcini.it>:

This patch series adds DMIC and DRC support to the WM8904 driver, a new
of_ helper is added to simplify the driver code.

DRC functionality is added in the same patch series to provide the
necessary dynamic range control to make DMIC support useful.

The WM8904 supports digital microphones on two of its inputs:
IN1L/DMICDAT1 and IN1R/DMICDAT2. These two inputs can either be
connected to an ADC or to the DMIC system. There is an ADC for each
line, and only one DMIC block. This DMIC block is either connected to
DMICDAT1 or to DMICDAT2. One DMIC data line supports two digital
microphones via time multiplexing.

The pin's functionality is decided during hardware design (IN1L vs
DMICDAT1 and IN1R vs DMICDAT2). This is reflected in the Device Tree.

If one line is analog and one is DMIC, we need to be able to switch
between ADC and DMIC at runtime. The DMIC source is known from the
Device Tree. If both are DMIC inputs, we need to be able to switch the
DMIC source. There is no need to switch between ADC and DMIC at runtime.

Therefore, kcontrols are dynamically added by the driver depending on
its Device Tree configuration.

This is a heavy rework of a previous patch series provided by Alifer
Moraes and Pierluigi Passaro,
https://lore.kernel.org/lkml/20220307141041.27538-1-alifer.m@variscite.com.

1 files changed, 3 insertions, 90 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index d4564a79eb35..6d616bb9001e 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -47,7 +47,6 @@
 #include <linux/splice.h>
 #include <linux/rcupdate_wait.h>
 #include <linux/sched/mm.h>
-#include <linux/fsnotify.h>
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
 #include "internal.h"
@@ -2897,8 +2896,7 @@ size_t splice_folio_into_pipe(struct pipe_inode_info *pipe,
 	size = min(size, folio_size(folio) - offset);
 	offset %= PAGE_SIZE;
 
-	while (spliced < size &&
-	       !pipe_full(pipe->head, pipe->tail, pipe->max_usage)) {
+	while (spliced < size && !pipe_is_full(pipe)) {
 		struct pipe_buffer *buf = pipe_head_buf(pipe);
 		size_t part = min_t(size_t, PAGE_SIZE - offset, size - spliced);
 
@@ -2955,7 +2953,7 @@ ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
 	iocb.ki_pos = *ppos;
 
 	/* Work out how much data we can actually add into the pipe */
-	used = pipe_occupancy(pipe->head, pipe->tail);
+	used = pipe_buf_usage(pipe);
 	npages = max_t(ssize_t, pipe->max_usage - used, 0);
 	len = min_t(size_t, len, npages * PAGE_SIZE);
 
@@ -3015,7 +3013,7 @@ ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
 			total_spliced += n;
 			*ppos += n;
 			in->f_ra.prev_pos = *ppos;
-			if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))
+			if (pipe_is_full(pipe))
 				goto out;
 		}
 
@@ -3199,14 +3197,6 @@ static struct file *do_sync_mmap_readahead(struct vm_fault *vmf)
 	unsigned long vm_flags = vmf->vma->vm_flags;
 	unsigned int mmap_miss;
 
-	/*
-	 * If we have pre-content watches we need to disable readahead to make
-	 * sure that we don't populate our mapping with 0 filled pages that we
-	 * never emitted an event for.
-	 */
-	if (unlikely(FMODE_FSNOTIFY_HSM(file->f_mode)))
-		return fpin;
-
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	/* Use the readahead code, even if readahead is disabled */
 	if ((vm_flags & VM_HUGEPAGE) && HPAGE_PMD_ORDER <= MAX_PAGECACHE_ORDER) {
@@ -3275,10 +3265,6 @@ static struct file *do_async_mmap_readahead(struct vm_fault *vmf,
 	struct file *fpin = NULL;
 	unsigned int mmap_miss;
 
-	/* See comment in do_sync_mmap_readahead. */
-	if (unlikely(FMODE_FSNOTIFY_HSM(file->f_mode)))
-		return fpin;
-
 	/* If we don't want any read-ahead, don't bother */
 	if (vmf->vma->vm_flags & VM_RAND_READ || !ra->ra_pages)
 		return fpin;
@@ -3338,48 +3324,6 @@ static vm_fault_t filemap_fault_recheck_pte_none(struct vm_fault *vmf)
 }
 
 /**
- * filemap_fsnotify_fault - maybe emit a pre-content event.
- * @vmf:	struct vm_fault containing details of the fault.
- *
- * If we have a pre-content watch on this file we will emit an event for this
- * range.  If we return anything the fault caller should return immediately, we
- * will return VM_FAULT_RETRY if we had to emit an event, which will trigger the
- * fault again and then the fault handler will run the second time through.
- *
- * Return: a bitwise-OR of %VM_FAULT_ codes, 0 if nothing happened.
- */
-vm_fault_t filemap_fsnotify_fault(struct vm_fault *vmf)
-{
-	struct file *fpin = NULL;
-	int mask = (vmf->flags & FAULT_FLAG_WRITE) ? MAY_WRITE : MAY_ACCESS;
-	loff_t pos = vmf->pgoff >> PAGE_SHIFT;
-	size_t count = PAGE_SIZE;
-	int err;
-
-	/*
-	 * We already did this and now we're retrying with everything locked,
-	 * don't emit the event and continue.
-	 */
-	if (vmf->flags & FAULT_FLAG_TRIED)
-		return 0;
-
-	/* No watches, we're done. */
-	if (likely(!FMODE_FSNOTIFY_HSM(vmf->vma->vm_file->f_mode)))
-		return 0;
-
-	fpin = maybe_unlock_mmap_for_io(vmf, fpin);
-	if (!fpin)
-		return VM_FAULT_SIGBUS;
-
-	err = fsnotify_file_area_perm(fpin, mask, &pos, count);
-	fput(fpin);
-	if (err)
-		return VM_FAULT_SIGBUS;
-	return VM_FAULT_RETRY;
-}
-EXPORT_SYMBOL_GPL(filemap_fsnotify_fault);
-
-/**
  * filemap_fault - read in file data for page fault handling
  * @vmf:	struct vm_fault containing details of the fault
  *
@@ -3483,37 +3427,6 @@ retry_find:
 	 */
 	if (unlikely(!folio_test_uptodate(folio))) {
 		/*
-		 * If this is a precontent file we have can now emit an event to
-		 * try and populate the folio.
-		 */
-		if (!(vmf->flags & FAULT_FLAG_TRIED) &&
-		    unlikely(FMODE_FSNOTIFY_HSM(file->f_mode))) {
-			loff_t pos = folio_pos(folio);
-			size_t count = folio_size(folio);
-
-			/* We're NOWAIT, we have to retry. */
-			if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT) {
-				folio_unlock(folio);
-				goto out_retry;
-			}
-
-			if (mapping_locked)
-				filemap_invalidate_unlock_shared(mapping);
-			mapping_locked = false;
-
-			folio_unlock(folio);
-			fpin = maybe_unlock_mmap_for_io(vmf, fpin);
-			if (!fpin)
-				goto out_retry;
-
-			error = fsnotify_file_area_perm(fpin, MAY_ACCESS, &pos,
-							count);
-			if (error)
-				ret = VM_FAULT_SIGBUS;
-			goto out_retry;
-		}
-
-		/*
 		 * If the invalidate lock is not held, the folio was in cache
 		 * and uptodate and now it is not. Strange but possible since we
 		 * didn't hold the page lock all the time. Let's drop