spi: rzv2h-rspi: Fix SPDR read access width for 16-bit RX

The RZ/V2H hardware manual (section 7.5.2.2.1) specifies that read access
size for the SPI Data Register (SPDR) are fixed at 32 bits. The
RZV2H_RSPI_RX macro for the 16-bit data path used readw(), violating
this requirement.

Switch to readl() for the 16-bit RX path to conform to the hardware
specification.

Fixes: 8b61c8919dff ("spi: Add driver for the RZ/V2H(P) RSPI IP")
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Link: https://patch.msgid.link/20260610-rzv2h-rspi-v2-1-40c80b4a2c90@gmail.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 1655efda7d20900d6a0d333ebd1a79c2999778c8..6ed3fad873b8cfa0efddf74b2f0857c84c2fa313 100644 (file)
--- a/drivers/spi/spi-rzv2h-rspi.c
+++ b/drivers/spi/spi-rzv2h-rspi.c
@@ -135,8 +135,9 @@ static inline void rzv2h_rspi_rx_##type(struct rzv2h_rspi_priv *rspi,       \
 RZV2H_RSPI_TX(writel, u32)
 RZV2H_RSPI_TX(writew, u16)
 RZV2H_RSPI_TX(writeb, u8)
+/* The read access size for RSPI_SPDR is fixed at 32 bits */
 RZV2H_RSPI_RX(readl, u32)
-RZV2H_RSPI_RX(readw, u16)
+RZV2H_RSPI_RX(readl, u16)
 RZV2H_RSPI_RX(readl, u8)
 
 static void rzv2h_rspi_reg_rmw(const struct rzv2h_rspi_priv *rspi,