change(esp32): undo forcing two slots in I2S

fix(i2s): fixed the issue in PR 14879

Closes espressif#14879

[Kevin: Update to only remove the limitation for PCM short format]

Author: gl-agnx

components/esp_driver_i2s/i2s_tdm.c

@@ -105,8 +105,8 @@ static esp_err_t i2s_tdm_set_slot(i2s_chan_handle_t handle, const i2s_tdm_slot_c
     handle->active_slot = slot_cfg->slot_mode == I2S_SLOT_MODE_MONO ? 1 : __builtin_popcount(slot_cfg->slot_mask);
     uint32_t max_slot_num = 32 - __builtin_clz(slot_cfg->slot_mask);
     handle->total_slot = slot_cfg->total_slot < max_slot_num ? max_slot_num : slot_cfg->total_slot;
-    handle->total_slot = handle->total_slot < 2 ? 2 : handle->total_slot;  // At least two slots in a frame
-
+    // At least two slots in a frame if not using PCM short format
+    handle->total_slot = ((handle->total_slot < 2) && (slot_cfg->ws_width != 1)) ? 2 : handle->total_slot;
     uint32_t buf_size = i2s_get_buf_size(handle, slot_cfg->data_bit_width, handle->dma.frame_num);
     /* The DMA buffer need to re-allocate if the buffer size changed */
     if (handle->dma.buf_size != buf_size) {

components/hal/i2s_hal.c

@@ -318,8 +318,8 @@ void i2s_hal_tdm_set_tx_slot(i2s_hal_context_t *hal, bool is_slave, const i2s_ha
     uint32_t msk = slot_cfg->tdm.slot_mask;
     /* Get the maximum slot number */
     cnt = 32 - __builtin_clz(msk);
-    /* There should be at least 2 slots in total even for mono mode */
-    cnt = cnt < 2 ? 2 : cnt;
+    /* Except PCM short format (ws_width = 1), there should be at least 2 slots in total even for mono mode */
+    cnt = ((cnt < 2) && (slot_cfg->tdm.ws_width != 1)) ? 2 : cnt;
     uint32_t total_slot = slot_cfg->tdm.total_slot > cnt ? slot_cfg->tdm.total_slot : cnt;
     i2s_ll_tx_reset(hal->dev);
     i2s_ll_tx_set_slave_mod(hal->dev, is_slave); //TX Slave
@@ -352,8 +352,8 @@ void i2s_hal_tdm_set_rx_slot(i2s_hal_context_t *hal, bool is_slave, const i2s_ha
     uint32_t msk = slot_cfg->tdm.slot_mask;
     /* Get the maximum slot number */
     cnt = 32 - __builtin_clz(msk);
-    /* There should be at least 2 slots in total even for mono mode */
-    cnt = cnt < 2 ? 2 : cnt;
+    /* Except PCM short format (ws_width = 1), there should be at least 2 slots in total even for mono mode */
+    cnt = ((cnt < 2) && (slot_cfg->tdm.ws_width != 1)) ? 2 : cnt;
     uint32_t total_slot = slot_cfg->tdm.total_slot > cnt ? slot_cfg->tdm.total_slot : cnt;
     i2s_ll_rx_reset(hal->dev);
     i2s_ll_rx_set_slave_mod(hal->dev, is_slave); //RX Slave