[PATCH v2 10/14] spi: dw: Add ENHANCED cap

[Sean Anderson]

This capability corresponds to an SSIC_SPI_MODE of 1, 2, or 3.  This
doesn't do much yet, but it does add support for detection and for
disallowing unsupported modes. Unfortunately, we cannot discriminate
between these modes (only that SSIC_SPI_MODE != 0), so we just pretend to
have DUAL+QUAD+OCTAL and let the slave determine what we actually use.

Signed-off-by: Sean Anderson <seanga2 at gmail.com>
---

Changes in v2:
- Merge CAP_{DUAL,QUAD,OCTAL} into CAP_ENHANCED

 drivers/spi/designware_spi.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/designware_spi.c b/drivers/spi/designware_spi.c
index 72cca14887..c2639141c6 100644
--- a/drivers/spi/designware_spi.c
+++ b/drivers/spi/designware_spi.c
@@ -129,6 +129,7 @@ struct dw_spi_priv {
 #define DW_SPI_CAP_KEEMBAY_MST		BIT(1) /* Unimplemented */
 #define DW_SPI_CAP_DWC_SSI		BIT(2)
 #define DW_SPI_CAP_DFS32		BIT(3)
+#define DW_SPI_CAP_ENHANCED		BIT(4)
 	unsigned long caps;
 	unsigned long bus_clk_rate;
 	unsigned int freq;		/* Default frequency */
@@ -141,6 +142,7 @@ struct dw_spi_priv {
 	u8 cs;				/* chip select pin */
 	u8 tmode;			/* TR/TO/RO/EEPROM */
 	u8 type;			/* SPI/SSP/MicroWire */
+	u8 spi_frf;			/* BYTE/DUAL/QUAD/OCTAL */
 };
 
 static inline u32 dw_read(struct dw_spi_priv *priv, u32 offset)
@@ -249,6 +251,18 @@ static void spi_hw_init(struct udevice *bus, struct dw_spi_priv *priv)
 	if (priv->caps & DW_SPI_CAP_DWC_SSI || !FIELD_GET(CTRLR0_DFS_MASK, cr0))
 		priv->caps |= DW_SPI_CAP_DFS32;
 
+	/*
+	 * If SPI_FRF exists that means we have DUAL, QUAD, or OCTAL. Since we
+	 * can't differentiate, just set a general ENHANCED cap and let the
+	 * slave decide what to use.
+	 */
+	if (priv->caps & DW_SPI_CAP_DWC_SSI) {
+		if (FIELD_GET(DWC_SSI_CTRLR0_SPI_FRF_MASK, cr0))
+			priv->caps |= DW_SPI_CAP_ENHANCED;
+	} else if (FIELD_GET(CTRLR0_SPI_FRF_MASK, cr0)) {
+		priv->caps |= DW_SPI_CAP_ENHANCED;
+	}
+
 	dw_write(priv, DW_SPI_SSIENR, 1);
 
 	/*
@@ -746,13 +760,19 @@ static int dw_spi_set_mode(struct udevice *bus, uint mode)
 {
 	struct dw_spi_priv *priv = dev_get_priv(bus);
 
+	if (!(priv->caps & DW_SPI_CAP_ENHANCED) &&
+	    (mode & (SPI_RX_DUAL | SPI_TX_DUAL |
+		     SPI_RX_QUAD | SPI_TX_QUAD |
+		     SPI_RX_OCTAL | SPI_TX_OCTAL)))
+		return -EINVAL;
+
 	/*
 	 * Can't set mode yet. Since this depends on if rx, tx, or
 	 * rx & tx is requested. So we have to defer this to the
 	 * real transfer function.
 	 */
 	priv->mode = mode;
-	dev_dbg(bus, "mode=%d\n", priv->mode);
+	dev_dbg(bus, "mode=%x\n", mode);
 
 	return 0;
 }
-- 
2.29.2