drivers: i3c: cadence: fix tx_fifo width for target mode on REV_ID 1.7

Cadence I3C target FIFO width has been increased to 4 bytes in i3c
hardware REV_ID 1.7. Writing 1 byte to 4 byte FIFOs can cause
unintentional padding for bytes written from TX threshold interrupt
handler. Fixed the target callback to handle tx width of i3c target
writes to FIFO, by using run time rev_id check.

Signed-off-by: Naveen Gangadharan <naveeng1001@meta.com>

drivers/i3c/i3c_cdns.c

@@ -2387,6 +2387,60 @@ static void cdns_i3c_target_ibi_hj_complete(const struct device *dev)
 }
 #endif
 
+static void cdns_i3c_target_sdr_tx_thr_int_handler(const struct device *dev,
+ const struct i3c_target_callbacks *target_cb)
+{
+ int status = 0;
+ struct cdns_i3c_data *data = dev->data;
+ const struct cdns_i3c_config *config = dev->config;
+
+ if (target_cb != NULL && target_cb->read_processed_cb) {
+ /* with REV_ID 1.7, as a target, the fifos are full word, otherwise only the first
+ * byte is used.
+ */
+ if (REV_ID_REV(data->hw_cfg.rev_id) >= REV_ID_VERSION(1, 7)) {
+ /* while tx fifo is not full and there is still data available */
+ while ((!(sys_read32(config->base + SLV_STATUS1) &
+ SLV_STATUS1_SDR_TX_FULL)) &&
+ (status == 0)) {
+ /* call function pointer for read */
+ uint32_t tx_data = 0;
+ bool data_valid = false;
+
+ for (int j = 0; j < 4; j++) {
+ uint8_t byte;
+ /* will return negative if no data left to transmit and 0
+ * if data available
+ */
+ status = target_cb->read_processed_cb(data->target_config,
+ &byte);
+ if (status == 0) {
+ data_valid = true;
+ tx_data |= (byte << (j * 8));
+ }
+ }
+ if (data_valid) {
+ cdns_i3c_write_tx_fifo(config, &tx_data, sizeof(uint32_t));
+ }
+ }
+ } else {
+ /* while tx fifo is not full and there is still data available */
+ while ((!(sys_read32(config->base + SLV_STATUS1) &
+ SLV_STATUS1_SDR_TX_FULL)) &&
+ (status == 0)) {
+ uint8_t byte;
+ /* will return negative if no data left to transmit and 0 if
+ * data available
+ */
+ status = target_cb->read_processed_cb(data->target_config, &byte);
+ if (status == 0) {
+ cdns_i3c_write_tx_fifo(config, &byte, sizeof(uint8_t));
+ }
+ }
+ }
+ }
+}
+
 static void cdns_i3c_irq_handler(const struct device *dev)
 {
  const struct cdns_i3c_config *config = dev->config;
@@ -2468,25 +2522,7 @@ static void cdns_i3c_irq_handler(const struct device *dev)
 
  /* SLV SDR tx fifo threshold */
  if (int_sl & SLV_INT_SDR_TX_THR) {
- int status = 0;
-
- if (target_cb != NULL && target_cb->read_processed_cb) {
- /* while tx fifo is not full and there is still data available */
- while ((!(sys_read32(config->base + SLV_STATUS1) &
- SLV_STATUS1_SDR_TX_FULL)) &&
- (status == 0)) {
- /* call function pointer for read */
- uint8_t byte;
- /* will return negative if no data left to transmit and 0 if
- * data available
- */
- status = target_cb->read_processed_cb(data->target_config,
- &byte);
- if (status == 0) {
- cdns_i3c_write_tx_fifo(config, &byte, sizeof(byte));
- }
- }
- }
+ cdns_i3c_target_sdr_tx_thr_int_handler(dev, target_cb);
  }
 
  /* SLV SDR rx complete */