+static int rt1015_set_tdm_slot(struct snd_soc_dai *dai,
+ unsigned int tx_mask, unsigned int rx_mask, int slots, int slot_width)
+{
+ struct snd_soc_component *component = dai->component;
+ unsigned int val = 0, rx_slotnum, tx_slotnum;
+ int ret = 0, first_bit;
+
+ switch (slots) {
+ case 4:
+ val |= RT1015_I2S_TX_4CH;
+ break;
+ case 6:
+ val |= RT1015_I2S_TX_6CH;
+ break;
+ case 8:
+ val |= RT1015_I2S_TX_8CH;
+ break;
+ case 2:
+ break;
nit-pick: I would put the case 2 first to keep the order. I thought for
a second this was an error case due to the discontinuity.
+ default:
+ ret = -EINVAL;
+ goto _set_tdm_err_;
+ }
+
+ switch (slot_width) {
+ case 20:
+ val |= RT1015_I2S_CH_TX_LEN_20B;
+ break;
+ case 24:
+ val |= RT1015_I2S_CH_TX_LEN_24B;
+ break;
+ case 32:
+ val |= RT1015_I2S_CH_TX_LEN_32B;
+ break;
+ case 16:
+ break;
nit-pick: same here, I would put 16 first.
+ default:
+ ret = -EINVAL;
+ goto _set_tdm_err_;
+ }
+
+ /* Rx slot configuration */
+ rx_slotnum = hweight_long(rx_mask);
+ if (rx_slotnum > 1 || !rx_slotnum) {
I am confused here, is this saying you can only have a single channel on RX?
If yes should this be simplified as if (rx_slotnum != 1) ?
+ ret = -EINVAL;
+ dev_err(component->dev, "too many rx slots or zero slot\n");
+ goto _set_tdm_err_;
+ }
+
+ first_bit = __ffs(rx_mask);
+ switch (first_bit) {
+ case 0:
+ case 2:
+ case 4:
+ case 6:
+ snd_soc_component_update_bits(component,
+ RT1015_PAD_DRV2, RT1015_MONO_LR_SEL_MASK,
+ RT1015_MONO_L_CHANNEL);
+ snd_soc_component_update_bits(component,
+ RT1015_TDM1_4,
+ RT1015_TDM_I2S_TX_L_DAC1_1_MASK |
+ RT1015_TDM_I2S_TX_R_DAC1_1_MASK,
+ (first_bit << RT1015_TDM_I2S_TX_L_DAC1_1_SFT) |
+ ((first_bit+1) << RT1015_TDM_I2S_TX_R_DAC1_1_SFT));
looks like there's an assumption that the rx mask has contiguous bits
set? Maybe add a comment to explain how the RX path works?
+ break;
+ case 1:
+ case 3:
+ case 5:
+ case 7:
+ snd_soc_component_update_bits(component,
+ RT1015_PAD_DRV2, RT1015_MONO_LR_SEL_MASK,
+ RT1015_MONO_R_CHANNEL);
+ snd_soc_component_update_bits(component,
+ RT1015_TDM1_4,
+ RT1015_TDM_I2S_TX_L_DAC1_1_MASK |
+ RT1015_TDM_I2S_TX_R_DAC1_1_MASK,
+ ((first_bit-1) << RT1015_TDM_I2S_TX_L_DAC1_1_SFT) |
+ (first_bit << RT1015_TDM_I2S_TX_R_DAC1_1_SFT));
+ break;
+ default:
+ ret = -EINVAL;
+ goto _set_tdm_err_;
+ }
+
+ /* Tx slot configuration */
+ tx_slotnum = hweight_long(tx_mask);
+ if (tx_slotnum) {
+ ret = -EINVAL;
+ dev_err(component->dev, "doesn't need to support tx slots\n");
+ goto _set_tdm_err_;
+ }
+
+ snd_soc_component_update_bits(component, RT1015_TDM1_1,
+ RT1015_I2S_CH_TX_MASK | RT1015_I2S_CH_RX_MASK |
+ RT1015_I2S_CH_TX_LEN_MASK | RT1015_I2S_CH_RX_LEN_MASK, val);
+
+_set_tdm_err_:
+ return ret;
+}
+
