summaryrefslogtreecommitdiff
path: root/sound/soc/soc-core.c
diff options
context:
space:
mode:
authorLars-Peter Clausen <lars@metafoo.de>2015-01-12 10:27:20 +0100
committerMark Brown <broonie@kernel.org>2015-01-14 19:04:57 +0000
commite46c93669349072f5caca853f5618cfa01b86008 (patch)
treed810795f3542215698bc06de799b42d41ee190ba /sound/soc/soc-core.c
parentbbcdb69dfcbd8842ee2a54265abd3e53cb3089e2 (diff)
ASoC: Update snd_soc_dai_set_tdm_slot() documentation
There have been some conflicting interpretations of how snd_soc_dai_set_tdm_slot() is supposed to work. This patch updates the documentation to be more specific on the exact semantics to avoid such problems in the future. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'sound/soc/soc-core.c')
-rw-r--r--sound/soc/soc-core.c20
1 files changed, 16 insertions, 4 deletions
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 985052b3fbed..64e047dc7cdf 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -2119,15 +2119,27 @@ static int snd_soc_xlate_tdm_slot_mask(unsigned int slots,
}
/**
- * snd_soc_dai_set_tdm_slot - configure DAI TDM.
- * @dai: DAI
+ * snd_soc_dai_set_tdm_slot() - Configures a DAI for TDM operation
+ * @dai: The DAI to configure
* @tx_mask: bitmask representing active TX slots.
* @rx_mask: bitmask representing active RX slots.
* @slots: Number of slots in use.
* @slot_width: Width in bits for each slot.
*
- * Configures a DAI for TDM operation. Both mask and slots are codec and DAI
- * specific.
+ * This function configures the specified DAI for TDM operation. @slot contains
+ * the total number of slots of the TDM stream and @slot_with the width of each
+ * slot in bit clock cycles. @tx_mask and @rx_mask are bitmasks specifying the
+ * active slots of the TDM stream for the specified DAI, i.e. which slots the
+ * DAI should write to or read from. If a bit is set the corresponding slot is
+ * active, if a bit is cleared the corresponding slot is inactive. Bit 0 maps to
+ * the first slot, bit 1 to the second slot and so on. The first active slot
+ * maps to the first channel of the DAI, the second active slot to the second
+ * channel and so on.
+ *
+ * TDM mode can be disabled by passing 0 for @slots. In this case @tx_mask,
+ * @rx_mask and @slot_width will be ignored.
+ *
+ * Returns 0 on success, a negative error code otherwise.
*/
int snd_soc_dai_set_tdm_slot(struct snd_soc_dai *dai,
unsigned int tx_mask, unsigned int rx_mask, int slots, int slot_width)