ASoC: soc-core: Ensure codec_reg has fixed length fields

Make the format of the codec_reg file more easily parsable.  Remove
the header field which gives the codec name.  These changes are important
when it comes to extend the debugfs codec_reg file to dump more than
PAGE_SIZE bytes to make it easier to calculate offsets within the
file.

We still need to handle the case when the snd_soc_read() call fails
and <no data: %d> is outputted.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 3feddd91b9734fe5e38e00e538242869b763ed68..205cbd7b149fa2ab1a24005c206c247a2c31447d 100644 (file)
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -69,10 +69,32 @@ static int pmdown_time = 5000;
 module_param(pmdown_time, int, 0);
 MODULE_PARM_DESC(pmdown_time, "DAPM stream powerdown time (msecs)");
 
+/* returns the minimum number of bytes needed to represent
+ * a particular given value */
+static int min_bytes_needed(unsigned long val)
+{
+       int c = 0;
+       int i;
+
+       for (i = (sizeof val * 8) - 1; i >= 0; --i, ++c)
+               if (val & (1UL << i))
+                       break;
+       c = (sizeof val * 8) - c;
+       if (!c || (c % 8))
+               c = (c + 8) / 8;
+       else
+               c /= 8;
+       return c;
+}
+
 /* codec register dump */
 static ssize_t soc_codec_reg_show(struct snd_soc_codec *codec, char *buf)
 {
        int ret, i, step = 1, count = 0;
+       int wordsize, regsize;
+
+       wordsize = codec->driver->reg_word_size * 2;
+       regsize = min_bytes_needed(codec->driver->reg_cache_size) * 2;
 
        if (!codec->driver->reg_cache_size)
                return 0;
@@ -80,12 +102,11 @@ static ssize_t soc_codec_reg_show(struct snd_soc_codec *codec, char *buf)
        if (codec->driver->reg_cache_step)
                step = codec->driver->reg_cache_step;
 
-       count += sprintf(buf, "%s registers\n", codec->name);
        for (i = 0; i < codec->driver->reg_cache_size; i += step) {
                if (codec->readable_register && !codec->readable_register(codec, i))
                        continue;
 
-               count += sprintf(buf + count, "%2x: ", i);
+               count += sprintf(buf + count, "%.*x: ", regsize, i);
                if (count >= PAGE_SIZE - 1)
                        break;
 
@@ -101,7 +122,7 @@ static ssize_t soc_codec_reg_show(struct snd_soc_codec *codec, char *buf)
                        if (ret >= 0)
                                count += snprintf(buf + count,
                                                  PAGE_SIZE - count,
-                                                 "%4x", ret);
+                                                 "%.*x", wordsize, ret);
                        else
                                count += snprintf(buf + count,
                                                  PAGE_SIZE - count,