add spi nor flash driver for mediatek controller

Signed-off-by: Bayi Cheng <redacted>
---
 drivers/mtd/spi-nor/Kconfig       |   7 +
 drivers/mtd/spi-nor/Makefile      |   1 +
 drivers/mtd/spi-nor/mtk_quadspi.c | 483 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 491 insertions(+)
 create mode 100644 drivers/mtd/spi-nor/mtk_quadspi.c

diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index 89bf4c1..f433890 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig

@@ -7,6 +7,13 @@ menuconfig MTD_SPI_NOR
 
 if MTD_SPI_NOR
 
+config MTD_MT81xx_NOR
+	tristate "Support SPI flash Controller MTD_MT81xx_NOR"
+	help
+	  This enables access to SPI Nor flash, using MTD_MT81XX_NOR controller.
+	  This controller does nor support generic SPI BUS, It only supports
+	  SPI NOR Flash.
+
 config MTD_SPI_NOR_USE_4K_SECTORS
 	bool "Use small 4096 B erase sectors"
 	default y

diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
index e53333e..138cfea 100644
--- a/drivers/mtd/spi-nor/Makefile
+++ b/drivers/mtd/spi-nor/Makefile

@@ -1,3 +1,4 @@
+obj-$(CONFIG_MTD_MT81xx_NOR)	+= mtk_quadspi.o
 obj-$(CONFIG_MTD_SPI_NOR)	+= spi-nor.o
 obj-$(CONFIG_SPI_FSL_QUADSPI)	+= fsl-quadspi.o
 obj-$(CONFIG_SPI_NXP_SPIFI)	+= nxp-spifi.o

diff --git a/drivers/mtd/spi-nor/mtk_quadspi.c b/drivers/mtd/spi-nor/mtk_quadspi.c
new file mode 100644
index 0000000..f60560e
--- /dev/null
+++ b/drivers/mtd/spi-nor/mtk_quadspi.c

@@ -0,0 +1,483 @@
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ * Author: Bayi Cheng <bayi.cheng@mediatek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/ioport.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/spi-nor.h>
+
+#define MTK_NOR_CMD_REG			0x00
+#define MTK_NOR_CNT_REG			0x04
+#define MTK_NOR_RDSR_REG		0x08
+#define MTK_NOR_RDATA_REG		0x0c
+#define MTK_NOR_RADR0_REG		0x10
+#define MTK_NOR_RADR1_REG		0x14
+#define MTK_NOR_RADR2_REG		0x18
+#define MTK_NOR_WDATA_REG		0x1c
+#define MTK_NOR_PRGDATA0_REG		0x20
+#define MTK_NOR_PRGDATA1_REG		0x24
+#define MTK_NOR_PRGDATA2_REG		0x28
+#define MTK_NOR_PRGDATA3_REG		0x2c
+#define MTK_NOR_PRGDATA4_REG		0x30
+#define MTK_NOR_PRGDATA5_REG		0x34
+#define MTK_NOR_SHREG0_REG		0x38
+#define MTK_NOR_SHREG1_REG		0x3c
+#define MTK_NOR_SHREG2_REG		0x40
+#define MTK_NOR_SHREG3_REG		0x44
+#define MTK_NOR_SHREG4_REG		0x48
+#define MTK_NOR_SHREG5_REG		0x4c
+#define MTK_NOR_SHREG6_REG		0x50
+#define MTK_NOR_SHREG7_REG		0x54
+#define MTK_NOR_SHREG8_REG		0x58
+#define MTK_NOR_SHREG9_REG		0x5c
+#define MTK_NOR_FLHCFG_REG		0x84
+#define MTK_NOR_PP_DATA_REG		0x98
+#define MTK_NOR_PREBUF_STUS_REG		0x9c
+#define MTK_NOR_INTRSTUS_REG		0xa8
+#define MTK_NOR_INTREN_REG		0xac
+#define MTK_NOR_TIME_REG		0x94
+#define MTK_NOR_CHKSUM_CTL_REG		0xb8
+#define MTK_NOR_CHKSUM_REG		0xbc
+#define MTK_NOR_CMD2_REG		0xc0
+#define MTK_NOR_WRPROT_REG		0xc4
+#define MTK_NOR_RADR3_REG		0xc8
+#define MTK_NOR_DUAL_REG		0xcc
+#define MTK_NOR_DELSEL0_REG		0xa0
+#define MTK_NOR_DELSEL1_REG		0xa4
+#define MTK_NOR_DELSEL2_REG		0xd0
+#define MTK_NOR_DELSEL3_REG		0xd4
+#define MTK_NOR_DELSEL4_REG		0xd8
+#define MTK_NOR_CFG1_REG		0x60
+#define MTK_NOR_CFG2_REG		0x64
+#define MTK_NOR_CFG3_REG		0x68
+#define MTK_NOR_STATUS0_REG		0x70
+#define MTK_NOR_STATUS1_REG		0x74
+#define MTK_NOR_STATUS2_REG		0x78
+#define MTK_NOR_STATUS3_REG		0x7c
+/* commands for mtk nor controller */
+#define MTK_NOR_READ_CMD		0x0
+#define MTK_NOR_RDSR_CMD		0x2
+#define MTK_NOR_PRG_CMD			0x4
+#define MTK_NOR_WR_CMD			0x10
+#define MTK_NOR_WRSR_CMD		0x20
+#define MTK_NOR_PIO_READ_CMD		0x81
+#define MTK_NOR_WR_BUF_ENABLE		0x1
+#define MTK_NOR_WR_BUF_DISABLE		0x0
+#define MTK_NOR_ENABLE_SF_CMD		0x30
+#define MTK_NOR_DUAD_ADDR_EN		0x8
+#define MTK_NOR_QUAD_READ_EN		0x4
+#define MTK_NOR_DUAL_ADDR_EN		0x2
+#define MTK_NOR_DUAL_READ_EN		0x1
+#define MTK_NOR_DUAL_DISABLE		0x0
+#define MTK_NOR_FAST_READ		0x1
+
+#define SFLASH_WRBUF_SIZE		128
+#define MAX_FLASHCOUNT			1
+#define SFLASHHWNAME_LEN		12
+#define SFLASH_MAX_DMA_SIZE		(1024 * 8)
+
+#define LOCAL_BUF_SIZE		(SFLASH_MAX_DMA_SIZE * 20)
+
+struct mt8173_nor {
+	struct mtd_info mtd;
+	struct spi_nor nor;
+	struct device *dev;
+	void __iomem *base;	/* nor flash base address */
+	struct clk *spi_clk;
+	struct clk *nor_clk;
+};
+
+static void mt8173_nor_set_read_mode(struct mt8173_nor *mt8173_nor)
+{
+	struct spi_nor *nor = &mt8173_nor->nor;
+
+	switch (nor->flash_read) {
+	case SPI_NOR_FAST:
+		writeb(SPINOR_OP_READ_FAST, mt8173_nor->base +
+		       MTK_NOR_PRGDATA3_REG);
+		writeb(MTK_NOR_FAST_READ, mt8173_nor->base +
+		       MTK_NOR_CFG1_REG);
+		break;
+	case SPI_NOR_DUAL:
+		writeb(SPINOR_OP_READ_1_1_2, mt8173_nor->base +
+		       MTK_NOR_PRGDATA3_REG);
+		writeb(MTK_NOR_DUAL_READ_EN, mt8173_nor->base +
+		       MTK_NOR_DUAL_REG);
+		break;
+	case SPI_NOR_QUAD:
+		writeb(SPINOR_OP_READ_1_1_4, mt8173_nor->base +
+		       MTK_NOR_PRGDATA3_REG);
+		writeb(MTK_NOR_QUAD_READ_EN, mt8173_nor->base +
+		       MTK_NOR_DUAL_REG);
+		break;
+	default:
+		writeb(SPINOR_OP_READ, mt8173_nor->base +
+		       MTK_NOR_PRGDATA3_REG);
+		writeb(MTK_NOR_DUAL_DISABLE, mt8173_nor->base +
+		       MTK_NOR_DUAL_REG);
+		break;
+	}
+}
+
+static int mt8173_nor_execute_cmd(struct mt8173_nor *mt8173_nor, u8 cmdval)
+{
+	int reg;
+	u8 val = cmdval & 0x1f;
+
+	writeb(cmdval, mt8173_nor->base + MTK_NOR_CMD_REG);
+	return readl_poll_timeout(mt8173_nor->base + MTK_NOR_CMD_REG, reg,
+				  !(reg & val), 100, 10000);
+}
+
+static int mt8173_nor_set_cmd(struct mt8173_nor *mt8173_nor, int addr, int len,
+			      int op)
+{
+	writeb(op, mt8173_nor->base + MTK_NOR_PRGDATA5_REG);
+	/*  send the address to nor flash
+	 *  MTK_NOR_PRGDATA5_REG is shifted first
+	 *  MTK_NOR_PRGDATA0_REG is shifted last
+	 */
+	writeb(((addr >> 16) & 0xff), mt8173_nor->base + MTK_NOR_PRGDATA4_REG);
+	writeb(((addr >> 8) & 0xff), mt8173_nor->base + MTK_NOR_PRGDATA3_REG);
+	writeb((addr & 0xff), mt8173_nor->base + MTK_NOR_PRGDATA2_REG);