diff mbox series

[4/7] spi: realtek-rtl: add parallel IO suppport

Message ID a9568128-172a-6693-c059-7b2be2cafb97@birger-koblitz.de (mailing list archive)
State New, archived
Headers show
Series [1/7] spi: realteak-rtl: Add support for RTL93xx SoCs | expand

Commit Message

Birger Koblitz Aug. 1, 2022, 6:19 a.m. UTC 
The Realtek SoCs are capable of dual and/or quad IO.
Add a function to enable this functionality.

Signed-off-by: Birger Koblitz <mail@birger-koblitz.de>
---
  drivers/spi/spi-realtek-rtl.c | 22 ++++++++++++++++++++++
  1 file changed, 22 insertions(+)
diff mbox series

Patch

diff --git a/drivers/spi/spi-realtek-rtl.c b/drivers/spi/spi-realtek-rtl.c
index 5979233522f4..25a90493bf6e 100644
--- a/drivers/spi/spi-realtek-rtl.c
+++ b/drivers/spi/spi-realtek-rtl.c
@@ -25,6 +25,9 @@  struct rtspi {
  #define RTL_SPI_SFCSR_CSB3		BIT(14)
  #define RTL_SPI_SFCSR_RDY		BIT(27)
  #define RTL_SPI_SFCSR_CS		BIT(24)
+#define RTL_SPI_SFCSR_WIDTH_MASK	~(0x03 << 25)
+#define RTL_SPI_SFCSR_WIDTH_DUAL	(0x01 << 25)
+#define RTL_SPI_SFCSR_WIDTH_QUAD	(0x02 << 25)
  #define RTL_SPI_SFCSR_LEN_MASK		~(0x03 << 28)
  #define RTL_SPI_SFCSR_LEN1		(0x00 << 28)
  #define RTL_SPI_SFCSR_LEN4		(0x03 << 28)
@@ -118,6 +121,25 @@  static void rcv1(struct rtspi *rtspi, u8 *buf)
  	*buf = readl(REG(RTL_SPI_SFDR)) >> 24;
  }

+static void set_mode(struct rtspi *rtspi, unsigned int mode)
+{
+	u32 value;
+
+	value = readl(REG(RTL_SPI_SFCSR));
+	value &= RTL_SPI_SFCSR_WIDTH_MASK;
+	switch (mode) {
+	case SPI_NBITS_QUAD:
+		value |= RTL_SPI_SFCSR_WIDTH_QUAD;
+		break;
+	case SPI_NBITS_DUAL:
+		value |= RTL_SPI_SFCSR_WIDTH_DUAL;
+		break;
+	default:
+		break;
+	}
+	writel(value, REG(RTL_SPI_SFCSR));
+}
+
  static int transfer_one(struct spi_controller *ctrl, struct spi_device *spi,
  			struct spi_transfer *xfer)
  {