spi: rzv2h-rspi: enable TX buffer empty interrupt

In preparation for implementing DMA support, enable the transmit buffer
empty interrupt, which is necessary for DMA to write more data to the
FIFO.

This does not affect the PIO mode as we do not even request the TX
interrupt line.

Signed-off-by: Cosmin Tanislav <cosmin-gabriel.tanislav.xa@renesas.com>
Link: https://patch.msgid.link/20251201134229.600817-9-cosmin-gabriel.tanislav.xa@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-rzv2h-rspi.c b/drivers/spi/spi-rzv2h-rspi.c
index 83bb0b7400b2173fca414657e9ba29fb5519b158..b31ef2f31f1b415b70b46b6a42d601835d6db6cb 100644 (file)
--- a/drivers/spi/spi-rzv2h-rspi.c
+++ b/drivers/spi/spi-rzv2h-rspi.c
@@ -37,6 +37,7 @@
 /* Register SPCR */
 #define RSPI_SPCR_BPEN         BIT(31)
 #define RSPI_SPCR_MSTR         BIT(30)
+#define RSPI_SPCR_SPTIE                BIT(20)
 #define RSPI_SPCR_SPRIE                BIT(17)
 #define RSPI_SPCR_SCKASE       BIT(12)
 #define RSPI_SPCR_SPE          BIT(0)
@@ -474,6 +475,9 @@ static int rzv2h_rspi_prepare_message(struct spi_controller *ctlr,
        /* SPI receive buffer full interrupt enable */
        conf32 |= RSPI_SPCR_SPRIE;
 
+       /* SPI transmit buffer empty interrupt enable */
+       conf32 |= RSPI_SPCR_SPTIE;
+
        /* Bypass synchronization circuit */
        conf32 |= FIELD_PREP(RSPI_SPCR_BPEN, rspi->use_pclk);