drm/tegra: hda: Extract HDA format parsing code

This code can be reused for HDMI, so extract it into a reusable
function.

Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/hda.c

@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (C) 2019 NVIDIA Corporation
+ */
+
+#include <linux/bug.h>
+
+#include <sound/hda_verbs.h>
+
+#include "hda.h"
+
+void tegra_hda_parse_format(unsigned int format, struct tegra_hda_format *fmt)
+{
+	unsigned int mul, div, bits, channels;
+
+	if (format & AC_FMT_TYPE_NON_PCM)
+		fmt->pcm = false;
+	else
+		fmt->pcm = true;
+
+	if (format & AC_FMT_BASE_44K)
+		fmt->sample_rate = 44100;
+	else
+		fmt->sample_rate = 48000;
+
+	mul = (format & AC_FMT_MULT_MASK) >> AC_FMT_MULT_SHIFT;
+	div = (format & AC_FMT_DIV_MASK) >> AC_FMT_DIV_SHIFT;
+
+	fmt->sample_rate *= (mul + 1) / (div + 1);
+
+	switch (format & AC_FMT_BITS_MASK) {
+	case AC_FMT_BITS_8:
+		fmt->bits = 8;
+		break;
+
+	case AC_FMT_BITS_16:
+		fmt->bits = 16;
+		break;
+
+	case AC_FMT_BITS_20:
+		fmt->bits = 20;
+		break;
+
+	case AC_FMT_BITS_24:
+		fmt->bits = 24;
+		break;
+
+	case AC_FMT_BITS_32:
+		fmt->bits = 32;
+		break;
+
+	default:
+		bits = (format & AC_FMT_BITS_MASK) >> AC_FMT_BITS_SHIFT;
+		WARN(1, "invalid number of bits: %#x\n", bits);
+		fmt->bits = 8;
+		break;
+	}
+
+	channels = (format & AC_FMT_CHAN_MASK) >> AC_FMT_CHAN_SHIFT;
+
+	/* channels are encoded as n - 1 */
+	fmt->channels = channels + 1;
+}