[RFC/RFT PATCH v1 6/9] mtd: spi: Enhance the fsl_qspi_read() method to support DUAL and QUAD

Lukasz Majewski
2018-09-26T22:09:06Z

This commit not only provides the DUAL and QUAD read capability for QSPI
controller, but also resets the AHB pointer sequence (as recommended) and
makes sure that AHB - not IP - mode is used for reading SPI-NOR data to
internal buffer.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
---
drivers/mtd/spi-nor/fsl-quadspi.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 0c381cdfb39f..97546fa70b79 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -119,6 +119,10 @@
#define QUADSPI_FR 0x160
#define QUADSPI_FR_TFF_MASK 0x1

+#define QUADSPI_SPTRCLR 0x16c
+#define QUADSPI_SPTRCLR_BFPTRC_SHIFT 0
+#define QUADSPI_SPTRCLR_BFPTRC_MASK (0x1 << QUADSPI_SPTRCLR_BFPTRC_SHIFT)
+
#define QUADSPI_SFA1AD 0x180
#define QUADSPI_SFA2AD 0x184
#define QUADSPI_SFB1AD 0x188
@@ -903,6 +907,22 @@ static ssize_t fsl_qspi_read(struct spi_nor *nor, loff_t from,
{
struct fsl_qspi *q = nor->priv;
u8 cmd = nor->read_opcode;
+ int seqid;
+
+ /* Set the actual lut sequence for AHB Read from the considered nor. */
+ seqid = fsl_qspi_get_seqid(q, nor->read_opcode);
+ if (seqid < 0)
+ return seqid;
+
+ qspi_writel(q, seqid << QUADSPI_BFGENCR_SEQID_SHIFT,
+ q->iobase + QUADSPI_BFGENCR);
+
+ /* Reset the AHB sequence pointer */
+ qspi_writel(q, QUADSPI_SPTRCLR_BFPTRC_MASK,
+ q->iobase + QUADSPI_SPTRCLR);
+
+ /* make sure the Rx buffer is read through AHB, not IP */
+ qspi_writel(q, QUADSPI_RBCT_WMRK_MASK, q->iobase + QUADSPI_RBCT);

/* if necessary,ioremap buffer before AHB read, */
if (!q->ahb_addr) {
--
2.11.0