[PATCH v2 16/30] spi: cadence_ospi_versal: ospi ddr changes in cadence ospi versal driver

[Tejas Bhumkar]

From: T Karthik Reddy <t.karthik.re...@xilinx.com>

Set cmd, address & data buswidth to octal. Handle dummy clock
cycles incase of reads & writes. Convert odd bytes to even
bytes lengths in ddr mode, as we cannot rx/tx odd data in
ddr mode.

Disable the DMA once the transfer is done to avoid disabling
it at other places.

Signed-off-by: T Karthik Reddy <t.karthik.re...@xilinx.com>
Signed-off-by: Tejas Bhumkar <tejas.arvind.bhum...@amd.com>
---
 drivers/spi/cadence_ospi_versal.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/cadence_ospi_versal.c 
b/drivers/spi/cadence_ospi_versal.c
index 243de6efaf..9db1911110 100644
--- a/drivers/spi/cadence_ospi_versal.c
+++ b/drivers/spi/cadence_ospi_versal.c
@@ -21,12 +21,13 @@
 
 #define CMD_4BYTE_READ  0x13
 #define CMD_4BYTE_FAST_READ  0x0C
+#define CMD_4BYTE_OCTAL_READ 0x7c
 
 int cadence_qspi_apb_dma_read(struct cadence_spi_priv *priv,
                              const struct spi_mem_op *op)
 {
        u32 reg, ret, rx_rem, n_rx, bytes_to_dma, data;
-       u8 opcode, addr_bytes, *rxbuf, dummy_cycles;
+       u8 opcode, addr_bytes, *rxbuf, dummy_cycles, unaligned_byte;
 
        n_rx = op->data.nbytes;
        rxbuf = op->data.buf.in;
@@ -70,13 +71,14 @@ int cadence_qspi_apb_dma_read(struct cadence_spi_priv *priv,
                writel(CQSPI_REG_INDIRECTRD_DONE, priv->regbase +
                       CQSPI_REG_INDIRECTRD);
                rxbuf += bytes_to_dma;
-       }
 
-       if (rx_rem) {
+               /* Disable DMA on completion */
                reg = readl(priv->regbase + CQSPI_REG_CONFIG);
                reg &= ~CQSPI_REG_CONFIG_ENBL_DMA;
                writel(reg, priv->regbase + CQSPI_REG_CONFIG);
+       }
 
+       if (rx_rem) {
                reg = readl(priv->regbase + CQSPI_REG_INDIRECTRDSTARTADDR);
                reg += bytes_to_dma;
                writel(reg, priv->regbase + CQSPI_REG_CMDADDRESS);
@@ -84,10 +86,10 @@ int cadence_qspi_apb_dma_read(struct cadence_spi_priv *priv,
                addr_bytes = readl(priv->regbase + CQSPI_REG_SIZE) &
                                   CQSPI_REG_SIZE_ADDRESS_MASK;
 
-               opcode = CMD_4BYTE_FAST_READ;
-               dummy_cycles = 8;
-               writel((dummy_cycles << CQSPI_REG_RD_INSTR_DUMMY_LSB) | opcode,
-                      priv->regbase + CQSPI_REG_RD_INSTR);
+               opcode = (u8)readl(priv->regbase + CQSPI_REG_RD_INSTR);
+               if (opcode == CMD_4BYTE_OCTAL_READ &&
+                   priv->edge_mode != CQSPI_EDGE_MODE_DDR)
+                       opcode = CMD_4BYTE_FAST_READ;
 
                reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
                reg |= (0x1 << CQSPI_REG_CMDCTRL_RD_EN_LSB);
@@ -99,7 +101,12 @@ int cadence_qspi_apb_dma_read(struct cadence_spi_priv *priv,
                                CQSPI_REG_RD_INSTR_DUMMY_MASK;
                reg |= (dummy_cycles & CQSPI_REG_CMDCTRL_DUMMY_MASK) <<
                        CQSPI_REG_CMDCTRL_DUMMY_LSB;
-               reg |= (((rx_rem - 1) & CQSPI_REG_CMDCTRL_RD_BYTES_MASK) <<
+               if (priv->edge_mode == CQSPI_EDGE_MODE_DDR && (rx_rem % 2) != 0)
+                       unaligned_byte = 1;
+               else
+                       unaligned_byte = 0;
+               reg |= (((rx_rem - 1 + unaligned_byte) &
+                       CQSPI_REG_CMDCTRL_RD_BYTES_MASK) <<
                        CQSPI_REG_CMDCTRL_RD_BYTES_LSB);
                ret = cadence_qspi_apb_exec_flash_cmd(priv->regbase, reg);
                if (ret)
-- 
2.27.0