Re: [PATCH] ASoC: rt1015: support TDM slot configuration

+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;

+}