[alsa-devel] [PATCH 1/1] ALSA: CA0132 - Handle endianness of SCP buffer data

[Ian Minett]

From: Ian Minett <ian_minett at creativelabs.com>

Handle endianness of the SCP buffer being sent to or from the
DSP chip on big-endian host architectures.
The SCP buffer is prepared in dspio_scp(), and bytes are swapped 
before being transferred by the codec in dspio_send().
Based on branch origin/topic/hda-ca0132-dsp.

We would appreciate any feedback you may have.
Thanks very much,
- Ian

Signed-off-by: Ian Minett <ian_minett at creativelabs.com>

diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c
index 2fd3121..8386a11 100644
--- a/sound/pci/hda/patch_ca0132.c
+++ b/sound/pci/hda/patch_ca0132.c
@@ -28,6 +28,7 @@
 #include <linux/mutex.h>
 #include <linux/module.h>
 #include <linux/firmware.h>
+#include <asm/unaligned.h>
 #include <sound/core.h>
 #include "hda_codec.h"
 #include "hda_local.h"
@@ -701,11 +702,16 @@ static int dspio_send(struct hda_codec *codec, unsigned int reg,
 	unsigned int res;
 	int retry = 50;
 
+	/* Handling for Big Endian machine */
+	unsigned int val;
+	put_unaligned_le32(data, &val);
+
 	/* send bits of data specified by reg to dsp */
 	do {
-		res = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0, reg, data);
-		if ((res >= 0) && (res != VENDOR_STATUS_DSPIO_BUSY))
-			return res;
+		res = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0, reg, val);
+		put_unaligned_le32(res, &val);
+		if ((val >= 0) && (val != VENDOR_STATUS_DSPIO_BUSY))
+			return val;
 	} while (--retry);
 
 	return -EIO;
@@ -719,11 +725,15 @@ static void dspio_write_wait(struct hda_codec *codec)
 	int status;
 	unsigned long timeout = jiffies + msecs_to_jiffies(1000);
 
+	/* Handling for Big Endian machine */
+	unsigned int val;
+
 	do {
 		status = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0,
 						VENDOR_DSPIO_STATUS, 0);
-		if ((status == VENDOR_STATUS_DSPIO_OK) ||
-		    (status == VENDOR_STATUS_DSPIO_SCP_RESPONSE_QUEUE_EMPTY))
+		put_unaligned_le32(status, &val);
+		if ((val == VENDOR_STATUS_DSPIO_OK) ||
+		    (val == VENDOR_STATUS_DSPIO_SCP_RESPONSE_QUEUE_EMPTY))
 			break;
 		msleep(1);
 	} while (time_before(jiffies, timeout));
@@ -736,6 +746,8 @@ static int dspio_write(struct hda_codec *codec, unsigned int scp_data)
 {
 	struct ca0132_spec *spec = codec->spec;
 	int status;
+	/* Handling for Big Endian machine */
+	unsigned int val = 0;
 
 	dspio_write_wait(codec);
 
@@ -751,8 +763,10 @@ static int dspio_write(struct hda_codec *codec, unsigned int scp_data)
 		goto error;
 
 	/* OK, now check if the write itself has executed*/
-	status = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0,
+	val = snd_hda_codec_read(codec, WIDGET_DSP_CTRL, 0,
 				    VENDOR_DSPIO_STATUS, 0);
+	put_unaligned_le32(val, &status);
+
 error:
 	mutex_unlock(&spec->chipio_mutex);
 
-- 
1.7.4.1