[U-Boot,18/20] spi: mtk_qspi: add qspi driver for MT7629 SoC

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 7d4d47d..0c37ac0 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -117,6 +117,13 @@  config MVEBU_A3700_SPI
 	  used to access the SPI NOR flash on platforms embedding this
 	  Marvell IP core.
 
+config MTK_QSPI
+	bool "Mediatek QSPI driver"
+	help
+	  Enable the Mediatek QSPI driver. This driver can be
+	  used to access the SPI NOR flash on platforms embedding this
+	  Mediatek QSPI IP core.
+
 config PIC32_SPI
 	bool "Microchip PIC32 SPI driver"
 	depends on MACH_PIC32
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 6679987..f1c6400 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -32,6 +32,7 @@  obj-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
 obj-$(CONFIG_LPC32XX_SSP) += lpc32xx_ssp.o
 obj-$(CONFIG_MPC8XX_SPI) += mpc8xx_spi.o
 obj-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
+obj-$(CONFIG_MTK_QSPI) += mtk_qspi.o
 obj-$(CONFIG_MVEBU_A3700_SPI) += mvebu_a3700_spi.o
 obj-$(CONFIG_MXC_SPI) += mxc_spi.o
 obj-$(CONFIG_MXS_SPI) += mxs_spi.o
diff --git a/drivers/spi/mtk_qspi.c b/drivers/spi/mtk_qspi.c
new file mode 100644
index 0000000..87117fa
--- /dev/null
+++ b/drivers/spi/mtk_qspi.c
@@ -0,0 +1,406 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018  MediaTek, Inc.
+ * Author : Guochun.Mao@mediatek.com
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <malloc.h>
+#include <spi.h>
+#include <asm/io.h>
+#include <linux/iopoll.h>
+#include <linux/ioport.h>
+
+/* Register Offset */
+struct mtk_qspi_regs {
+	u32 cmd;
+	u32 cnt;
+	u32 rdsr;
+	u32 rdata;
+	u32 radr[3];
+	u32 wdata;
+	u32 prgdata[6];
+	u32 shreg[10];
+	u32 cfg[2];
+	u32 shreg10;
+	u32 mode_mon;
+	u32 status[4];
+	u32 flash_time;
+	u32 flash_cfg;
+	u32 reserved_0[3];
+	u32 sf_time;
+	u32 pp_dw_data;
+	u32 reserved_1;
+	u32 delsel_0[2];
+	u32 intrstus;
+	u32 intren;
+	u32 reserved_2;
+	u32 cfg3;
+	u32 reserved_3;
+	u32 chksum;
+	u32 aaicmd;
+	u32 wrprot;
+	u32 radr3;
+	u32 dual;
+	u32 delsel_1[3];
+};
+
+struct mtk_qspi_platdata {
+	fdt_addr_t reg_base;
+	fdt_addr_t mem_base;
+};
+
+struct mtk_qspi_priv {
+	struct mtk_qspi_regs *regs;
+	unsigned long *mem_base;
+	u8 op;
+	/* Max paras length is 3 bytes. */
+	u8 tx[3];
+	u32 txlen;
+	u8 *rx;
+	u32 rxlen;
+};
+
+#define MTK_QSPI_CMD_POLLINGREG_US 500000
+#define MTK_QSPI_WRBUF_SIZE        256
+#define MTK_QSPI_COMMAND_ENABLE    0x30
+
+/* NOR flash controller commands */
+#define MTK_QSPI_RD_TRIGGER        BIT(0)
+#define MTK_QSPI_READSTATUS        BIT(1)
+#define MTK_QSPI_PRG_CMD           BIT(2)
+#define MTK_QSPI_WR_TRIGGER        BIT(4)
+#define MTK_QSPI_WRITESTATUS       BIT(5)
+#define MTK_QSPI_AUTOINC           BIT(7)
+
+/* NOR flash commands */
+#define MTK_QSPI_OP_WREN           0x6
+#define MTK_QSPI_OP_READ_QUAD      0x6B
+#define MTK_QSPI_OP_READ_DUAL      0x3B
+#define MTK_QSPI_OP_FAST_READ      0xB
+#define MTK_QSPI_OP_READ           0x3
+#define MTK_QSPI_OP_PP             0x2
+
+#define MTK_QSPI_MAX_RX_TX_SHIFT   0x6
+#define MTK_QSPI_MAX_SHIFT         0x8
+
+#define MTK_QSPI_WR_BUF_ENABLE     0x1
+#define MTK_QSPI_WR_BUF_DISABLE    0x0
+
+#define MTK_QSPI_FAST_READ_ENABLE  0x1
+#define MTK_QSPI_FAST_READ_DISABLE 0x0
+
+#define MTK_QSPI_READ_MODE_MASK    0x1f
+#define MTK_QSPI_READ_QUAD_EN      0x4
+#define MTK_QSPI_READ_DUAL_EN      0x1
+
+static int mtk_qspi_execute_cmd(struct mtk_qspi_priv *priv, u8 cmd)
+{
+	u8 tmp;
+	u8 val = cmd & ~MTK_QSPI_AUTOINC;
+
+	writeb(cmd, &priv->regs->cmd);
+
+	return readb_poll_timeout(&priv->regs->cmd, tmp, !(val & tmp),
+		MTK_QSPI_CMD_POLLINGREG_US);
+}
+
+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);
+	if (ret)
+		return ret;
+
+	/* restart at first RX byte */
+	idx = priv->rxlen - 1;
+
+	/* read out RX data */
+	for (i = 0; i < priv->rxlen; i++, idx--)
+		priv->rx[i] = readb(&priv->regs->shreg[idx]);
+
+	return 0;
+}
+
+static void mtk_qspi_set_read_mode(struct mtk_qspi_priv *priv)
+{
+	u8 val = readb(&priv->regs->dual) & (~MTK_QSPI_READ_MODE_MASK);
+
+	/* clean fast read bit */
+	writeb(MTK_QSPI_FAST_READ_DISABLE, &priv->regs->cfg[0]);
+
+	switch (priv->op) {
+	case MTK_QSPI_OP_FAST_READ:
+		writeb(MTK_QSPI_FAST_READ_ENABLE, &priv->regs->cfg[0]);
+		break;
+	case MTK_QSPI_OP_READ_DUAL:
+		writeb(priv->op, &priv->regs->prgdata[3]);
+		val |= MTK_QSPI_READ_DUAL_EN;
+		break;
+	case MTK_QSPI_OP_READ_QUAD:
+		writeb(priv->op, &priv->regs->prgdata[4]);
+		val |= MTK_QSPI_READ_QUAD_EN;
+		break;
+	default:
+		break;
+	}
+
+	writeb(val, &priv->regs->dual);
+}
+
+static int mtk_qspi_read(struct mtk_qspi_priv *priv,
+			 u32 addr, u8 *buf, u32 len)
+{
+	memcpy(buf, (u8 *)priv->mem_base + addr, len);
+	return 0;
+}
+
+static void mtk_qspi_set_addr(struct mtk_qspi_priv *priv, u32 addr)
+{
+	int i;
+
+	for (i = 0; i < 3; i++) {
+		writeb(addr & 0xff, &priv->regs->radr[i]);
+		addr >>= 8;
+	}
+}
+
+static int mtk_qspi_write_single_byte(struct mtk_qspi_priv *priv,
+				      u32 addr, u32 length, const u8 *data)
+{
+	int i, ret;
+
+	mtk_qspi_set_addr(priv, addr);
+
+	for (i = 0; i < length; i++) {
+		writeb(*data++, &priv->regs->wdata);
+		ret = mtk_qspi_execute_cmd(priv, MTK_QSPI_WR_TRIGGER);
+		if (ret < 0)
+			return ret;
+	}
+	return 0;
+}
+
+static int mtk_qspi_write_buffer(struct mtk_qspi_priv *priv, u32 addr,
+				 const u8 *buf)
+{
+	int i, data;
+
+	mtk_qspi_set_addr(priv, addr);
+
+	for (i = 0; i < MTK_QSPI_WRBUF_SIZE; i += 4) {
+		data = buf[i + 3] << 24 | buf[i + 2] << 16 |
+		       buf[i + 1] << 8 | buf[i];
+		writel(data, &priv->regs->pp_dw_data);
+	}
+
+	return mtk_qspi_execute_cmd(priv, MTK_QSPI_WR_TRIGGER);
+}
+
+static int mtk_qspi_write(struct mtk_qspi_priv *priv,
+			  u32 addr, const u8 *buf, u32 len)
+{
+	int ret;
+
+	/* setting pre-fetch buffer for page program*/
+	writel(MTK_QSPI_WR_BUF_ENABLE, &priv->regs->cfg[1]);
+	while (len >= MTK_QSPI_WRBUF_SIZE) {
+		ret = mtk_qspi_write_buffer(priv, addr, buf);
+		if (ret < 0)
+			return ret;
+
+		len -= MTK_QSPI_WRBUF_SIZE;
+		addr += MTK_QSPI_WRBUF_SIZE;
+		buf += MTK_QSPI_WRBUF_SIZE;
+	}
+	/* disable pre-fetch buffer for page program*/
+	writel(MTK_QSPI_WR_BUF_DISABLE, &priv->regs->cfg[1]);
+
+	if (len)
+		return mtk_qspi_write_single_byte(priv, addr, len, buf);
+
+	return 0;
+}
+
+static int mtk_qspi_claim_bus(struct udevice *dev)
+{
+	/* Nothing to do */
+	return 0;
+}
+
+static int mtk_qspi_release_bus(struct udevice *dev)
+{
+	/* Nothing to do */
+	return 0;
+}
+
+static int mtk_qspi_transfer(struct mtk_qspi_priv *priv, unsigned int bitlen,
+			     const void *dout, void *din, unsigned long flags)
+{
+	u32 bytes = DIV_ROUND_UP(bitlen, 8);
+	u32 addr;
+
+	if (!bytes)
+		return -ERR_INVAL;
+
+	if (dout) {
+		if (flags & SPI_XFER_BEGIN) {
+			/* dout format unknown here,
+			 * parse op code & potential paras first.
+			 */
+			priv->op = *(u8 *)dout;
+			if (bytes > 1)
+				memcpy(priv->tx, (u8 *)dout + 1,
+				       bytes <= 4 ? bytes - 1 : 3);
+			priv->txlen = bytes - 1;
+		}
+
+		if (flags == SPI_XFER_END) {
+			if (priv->op == MTK_QSPI_OP_PP) {
+				/* here dout format should be:
+				 * 1B op-code + 3B address + data
+				 */
+				if (bytes <= 4)
+					return -ERR_INVAL;
+				addr = priv->tx[0] << 16 | priv->tx[1] << 8 |
+				       priv->tx[2];
+				return mtk_qspi_write(priv, addr,
+						      (u8 *)dout + 4,
+						      bytes - 4);
+			}
+
+			/* operations without reveiving data. */
+			priv->rx = NULL;
+			priv->rxlen = 0;
+			return mtk_qspi_tx_rx(priv);
+		}
+	}
+
+	if (din) {
+		if (priv->op == MTK_QSPI_OP_READ ||
+		    priv->op == MTK_QSPI_OP_FAST_READ ||
+		    priv->op == MTK_QSPI_OP_READ_DUAL ||
+		    priv->op == MTK_QSPI_OP_READ_QUAD) {
+			/* if run to here, priv->tx[3] should be the address
+			 * where read data from,
+			 * and, din is the buf to receive data.
+			 */
+			mtk_qspi_set_read_mode(priv);
+			addr = priv->tx[0] << 16 | priv->tx[1] << 8 |
+			       priv->tx[2];
+			return mtk_qspi_read(priv, addr, (u8 *)din, bytes);
+		}
+
+		/* would be reading flash register */
+		priv->rx = (u8 *)din;
+		priv->rxlen = bytes;
+		return mtk_qspi_tx_rx(priv);
+	}
+
+	return 0;
+}
+
+static int mtk_qspi_xfer(struct udevice *dev, unsigned int bitlen,
+			 const void *dout, void *din, unsigned long flags)
+{
+	struct udevice *bus = dev->parent;
+	struct mtk_qspi_priv *priv = dev_get_priv(bus);
+
+	return  mtk_qspi_transfer(priv, bitlen, dout, din, flags);
+}
+
+static int mtk_qspi_set_speed(struct udevice *bus, uint speed)
+{
+	/* Nothing to do */
+	return 0;
+}
+
+static int mtk_qspi_set_mode(struct udevice *bus, uint mode)
+{
+	/* Nothing to do */
+	return 0;
+}
+
+static int mtk_qspi_ofdata_to_platdata(struct udevice *bus)
+{
+	struct resource res_reg, res_mem;
+	struct mtk_qspi_platdata *plat = bus->platdata;
+	int ret;
+
+	ret = dev_read_resource_byname(bus, "reg_base", &res_reg);
+	if (ret) {
+		debug("Error: can't get regs base address(ret = %d)!\n", ret);
+		return -ENOMEM;
+	}
+	ret = dev_read_resource_byname(bus, "mem_base", &res_mem);
+	if (ret) {
+		debug("Error: can't get mmap base address(ret = %d)!\n", ret);
+		return -ENOMEM;
+	}
+	plat->mem_base = res_mem.start;
+	plat->reg_base = res_reg.start;
+
+	return 0;
+}
+
+static int mtk_qspi_probe(struct udevice *bus)
+{
+	struct mtk_qspi_platdata *plat = dev_get_platdata(bus);
+	struct mtk_qspi_priv *priv = dev_get_priv(bus);
+
+	priv->regs = (struct mtk_qspi_regs *)plat->reg_base;
+	priv->mem_base = (unsigned long *)plat->mem_base;
+
+	writel(MTK_QSPI_COMMAND_ENABLE, &priv->regs->wrprot);
+
+	return 0;
+}
+
+static const struct dm_spi_ops mtk_qspi_ops = {
+	.claim_bus      = mtk_qspi_claim_bus,
+	.release_bus    = mtk_qspi_release_bus,
+	.xfer           = mtk_qspi_xfer,
+	.set_speed      = mtk_qspi_set_speed,
+	.set_mode       = mtk_qspi_set_mode,
+};
+
+static const struct udevice_id mtk_qspi_ids[] = {
+	{ .compatible = "mediatek,mt7629-qspi" },
+	{ }
+};
+
+U_BOOT_DRIVER(mtk_qspi) = {
+	.name     = "mtk_qspi",
+	.id       = UCLASS_SPI,
+	.of_match = mtk_qspi_ids,
+	.ops      = &mtk_qspi_ops,
+	.ofdata_to_platdata       = mtk_qspi_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct mtk_qspi_platdata),
+	.priv_auto_alloc_size     = sizeof(struct mtk_qspi_priv),
+	.probe    = mtk_qspi_probe,
+};