Hi Jagan,
On Wed, 2018-11-21 at 15:08 +0530, Jagan Teki wrote:
+static int mtk_qspi_tx_rx(struct mtk_qspi_priv *priv) +{
int len = 1 + priv->txlen + priv->rxlen;int i, ret, idx;if (len > MTK_QSPI_MAX_SHIFT)return -ERR_INVAL;writeb(len * 8, &priv->regs->cnt);/* start at PRGDATA5, go down to PRGDATA0 */idx = MTK_QSPI_MAX_RX_TX_SHIFT - 1;/* opcode */writeb(priv->op, &priv->regs->prgdata[idx]);idx--;/* program TX data */for (i = 0; i < priv->txlen; i++, idx--)writeb(priv->tx[i], &priv->regs->prgdata[idx]);/* clear out rest of TX registers */while (idx >= 0) {writeb(0, &priv->regs->prgdata[idx]);idx--;}ret = mtk_qspi_execute_cmd(priv, MTK_QSPI_PRG_CMD);What does this execute do?
It send command to flash, and latch data if need.
does it intiate the controller register based flash command or so?
No, it doesn't.
Do you have Linux driver on the controller?
Yes, it's drivers/mtd/spi-nor/mtk-quadspi.c
This sounds more specific to flash controller rather than spi driver. Can you try to write driver in mtd side itself, like Linux spi-nor. use UCLASS_SPI_FLASH
Sorry, I'm a little confused. There are many files(***qspi.c) those that used for accessing spi flash under folder drivers/spi/. However, there's no specific flash controller driver implemented under drives/mtd, only common spi_flash framework. It's different with kernel. It seems that we only need implement the spi control logic of spi-flash-controller(this part not based on flash, it only do data-xfer), and spi_flash framework will work well base on it. Isn't that the purpose of this architecture?