drivers: i2s: nrf_tdm: Add guards for buffers size

TDM peripheral requires TXD.MAXCNT and RXD.MAXCNT registers to be:
- multiple of 4 bytes
- larger than 8 bytes

Signed-off-by: Adam Kondraciuk <[email protected]>

Author: adamkondraciuk

drivers/i2s/i2s_nrf_tdm.c

@@ -32,6 +32,11 @@ LOG_MODULE_REGISTER(tdm_nrf, CONFIG_I2S_LOG_LEVEL);
  */
 #define NRFX_TDM_STATUS_TRANSFER_STOPPED BIT(1)
 
+/* Due to hardware limitations, the TDM peripheral requires the rx/tx size
+ * to be greater than 8 bytes.
+ */
+#define NRFX_TDM_MIN_TRANSFER_SIZE_ALLOWED 8
+
 /* Maximum clock divider value. Corresponds to CKDIV2. */
 #define NRFX_TDM_MAX_SCK_DIV_VALUE TDM_CONFIG_SCK_DIV_SCKDIV_Max
 #define NRFX_TDM_MAX_MCK_DIV_VALUE TDM_CONFIG_MCK_DIV_DIV_Max
@@ -475,8 +480,10 @@ static int tdm_nrf_configure(const struct device *dev, enum i2s_dir dir,
 
 	__ASSERT_NO_MSG(tdm_cfg->mem_slab != NULL && tdm_cfg->block_size != 0);
 
-	if ((tdm_cfg->block_size % sizeof(uint32_t)) != 0) {
-		LOG_ERR("This device can transfer only full 32-bit words");
+	if ((tdm_cfg->block_size % sizeof(uint32_t)) != 0 ||
+		tdm_cfg->block_size <= NRFX_TDM_MIN_TRANSFER_SIZE_ALLOWED) {
+		LOG_ERR("This device can only transmit full 32-bit words greater than %u bytes.",
+			NRFX_TDM_MIN_TRANSFER_SIZE_ALLOWED);
 		return -EINVAL;
 	}
 
@@ -673,11 +680,18 @@ static int tdm_nrf_write(const struct device *dev, void *mem_block, size_t size)
 		return -EIO;
 	}
 
-	if (size > drv_data->tx.cfg.block_size || size < sizeof(uint32_t)) {
+	if (size > drv_data->tx.cfg.block_size) {
 		LOG_ERR("This device can only write blocks up to %u bytes",
 			drv_data->tx.cfg.block_size);
 		return -EIO;
 	}
+
+	if ((size % sizeof(uint32_t)) != 0 || size <= NRFX_TDM_MIN_TRANSFER_SIZE_ALLOWED) {
+		LOG_ERR("This device can only write full 32-bit words greater than %u bytes.",
+			NRFX_TDM_MIN_TRANSFER_SIZE_ALLOWED);
+		return -EIO;
+	}
+
 	ret = dmm_buffer_out_prepare(drv_cfg->mem_reg, buf.mem_block, buf.size,
 				     (void **)&buf.dmm_buf);
 	ret = k_msgq_put(&drv_data->tx_queue, &buf, SYS_TIMEOUT_MS(drv_data->tx.cfg.timeout));