ASoC: sti: helper functions for unip tdm slots configuration

[cascardo/linux.git] / sound / soc / sti / sti_uniperif.c

diff --git a/sound/soc/sti/sti_uniperif.c b/sound/soc/sti/sti_uniperif.c
index 39bcefe..0c2474c 100644 (file)
--- a/sound/soc/sti/sti_uniperif.c
+++ b/sound/soc/sti/sti_uniperif.c
@@ -10,6 +10,96 @@
 
 #include "uniperif.h"
 
+/*
+ * User frame size shall be 2, 4, 6 or 8 32-bits words length
+ * (i.e. 8, 16, 24 or 32 bytes)
+ * This constraint comes from allowed values for
+ * UNIPERIF_I2S_FMT_NUM_CH register
+ */
+#define UNIPERIF_MAX_FRAME_SZ 0x20
+#define UNIPERIF_ALLOWED_FRAME_SZ (0x08 | 0x10 | 0x18 | UNIPERIF_MAX_FRAME_SZ)
+
+int sti_uniperiph_set_tdm_slot(struct snd_soc_dai *dai, unsigned int tx_mask,
+                              unsigned int rx_mask, int slots,
+                              int slot_width)
+{
+       struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
+       struct uniperif *uni = priv->dai_data.uni;
+       int i, frame_size, avail_slots;
+
+       if (!UNIPERIF_TYPE_IS_TDM(uni)) {
+               dev_err(uni->dev, "cpu dai not in tdm mode\n");
+               return -EINVAL;
+       }
+
+       /* store info in unip context */
+       uni->tdm_slot.slots = slots;
+       uni->tdm_slot.slot_width = slot_width;
+       /* unip is unidirectionnal */
+       uni->tdm_slot.mask = (tx_mask != 0) ? tx_mask : rx_mask;
+
+       /* number of available timeslots */
+       for (i = 0, avail_slots = 0; i < uni->tdm_slot.slots; i++) {
+               if ((uni->tdm_slot.mask >> i) & 0x01)
+                       avail_slots++;
+       }
+       uni->tdm_slot.avail_slots = avail_slots;
+
+       /* frame size in bytes */
+       frame_size = uni->tdm_slot.avail_slots * uni->tdm_slot.slot_width / 8;
+
+       /* check frame size is allowed */
+       if ((frame_size > UNIPERIF_MAX_FRAME_SZ) ||
+           (frame_size & ~(int)UNIPERIF_ALLOWED_FRAME_SZ)) {
+               dev_err(uni->dev, "frame size not allowed: %d bytes\n",
+                       frame_size);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+int sti_uniperiph_get_tdm_word_pos(struct uniperif *uni,
+                                  unsigned int *word_pos)
+{
+       int slot_width = uni->tdm_slot.slot_width / 8;
+       int slots_num = uni->tdm_slot.slots;
+       unsigned int slots_mask = uni->tdm_slot.mask;
+       int i, j, k;
+       unsigned int word16_pos[4];
+
+       /* word16_pos:
+        * word16_pos[0] = WORDX_LSB
+        * word16_pos[1] = WORDX_MSB,
+        * word16_pos[2] = WORDX+1_LSB
+        * word16_pos[3] = WORDX+1_MSB
+        */
+
+       /* set unip word position */
+       for (i = 0, j = 0, k = 0; (i < slots_num) && (k < WORD_MAX); i++) {
+               if ((slots_mask >> i) & 0x01) {
+                       word16_pos[j] = i * slot_width;
+
+                       if (slot_width == 4) {
+                               word16_pos[j + 1] = word16_pos[j] + 2;
+                               j++;
+                       }
+                       j++;
+
+                       if (j > 3) {
+                               word_pos[k] = word16_pos[1] |
+                                             (word16_pos[0] << 8) |
+                                             (word16_pos[3] << 16) |
+                                             (word16_pos[2] << 24);
+                               j = 0;
+                               k++;
+                       }
+               }
+       }
+
+       return 0;
+}
+
 /*
  * sti_uniperiph_dai_create_ctrl
  * This function is used to create Ctrl associated to DAI but also pcm device.