ALSA: pcm: Minor refactoring

Make a common helper for validating the format type.
This reduces the number of cast in the code that are needed for
suppressing sparse warnings.

No functional changes, just minor refactoring.

Link: https://lore.kernel.org/r/20200206163945.6797-9-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/pcm_misc.c

@@ -42,6 +42,11 @@ struct pcm_format_data {
 /* we do lots of calculations on snd_pcm_format_t; shut up sparse */
 #define INT	__force int
 
+static bool valid_format(snd_pcm_format_t format)
+{
+	return (INT)format >= 0 && (INT)format <= (INT)SNDRV_PCM_FORMAT_LAST;
+}
+
 static const struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
 	[SNDRV_PCM_FORMAT_S8] = {
 		.width = 8, .phys = 8, .le = -1, .signd = 1,
@@ -259,7 +264,7 @@ static const struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] =
 int snd_pcm_format_signed(snd_pcm_format_t format)
 {
 	int val;
-	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
+	if (!valid_format(format))
 		return -EINVAL;
 	if ((val = pcm_formats[(INT)format].signd) < 0)
 		return -EINVAL;
@@ -307,7 +312,7 @@ EXPORT_SYMBOL(snd_pcm_format_linear);
 int snd_pcm_format_little_endian(snd_pcm_format_t format)
 {
 	int val;
-	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
+	if (!valid_format(format))
 		return -EINVAL;
 	if ((val = pcm_formats[(INT)format].le) < 0)
 		return -EINVAL;
@@ -343,7 +348,7 @@ EXPORT_SYMBOL(snd_pcm_format_big_endian);
 int snd_pcm_format_width(snd_pcm_format_t format)
 {
 	int val;
-	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
+	if (!valid_format(format))
 		return -EINVAL;
 	if ((val = pcm_formats[(INT)format].width) == 0)
 		return -EINVAL;
@@ -361,7 +366,7 @@ EXPORT_SYMBOL(snd_pcm_format_width);
 int snd_pcm_format_physical_width(snd_pcm_format_t format)
 {
 	int val;
-	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
+	if (!valid_format(format))
 		return -EINVAL;
 	if ((val = pcm_formats[(INT)format].phys) == 0)
 		return -EINVAL;
@@ -394,7 +399,7 @@ EXPORT_SYMBOL(snd_pcm_format_size);
  */
 const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
 {
-	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
+	if (!valid_format(format))
 		return NULL;
 	if (! pcm_formats[(INT)format].phys)
 		return NULL;
@@ -418,7 +423,7 @@ int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int
 	unsigned char *dst;
 	const unsigned char *pat;
 
-	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
+	if (!valid_format(format))
 		return -EINVAL;
 	if (samples == 0)
 		return 0;