mtd: mtk-nor: new Mediatek serial flash controller driver

Add spi nor flash driver for mediatek controller

Signed-off-by: Bayi Cheng <bayi.cheng@mediatek.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/spi-nor/Kconfig

@@ -7,6 +7,13 @@ menuconfig MTD_SPI_NOR
 
 if MTD_SPI_NOR
 
+config MTD_MT81xx_NOR
+	tristate "Mediatek MT81xx SPI NOR flash controller"
+	help
+	  This enables access to SPI NOR flash, using MT81xx SPI NOR flash
+	  controller. This controller does not 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

drivers/mtd/spi-nor/Makefile

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

drivers/mtd/spi-nor/mtk-quadspi.c

@@ -0,0 +1,486 @@
+/*
+ * 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/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_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
+#define MTK_NOR_FLHCFG_REG		0x84
+#define MTK_NOR_TIME_REG		0x94
+#define MTK_NOR_PP_DATA_REG		0x98
+#define MTK_NOR_PREBUF_STUS_REG		0x9c
+#define MTK_NOR_DELSEL0_REG		0xa0
+#define MTK_NOR_DELSEL1_REG		0xa4
+#define MTK_NOR_INTRSTUS_REG		0xa8
+#define MTK_NOR_INTREN_REG		0xac
+#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_DELSEL2_REG		0xd0
+#define MTK_NOR_DELSEL3_REG		0xd4
+#define MTK_NOR_DELSEL4_REG		0xd8
+
+/* 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_PIO_WR_CMD		0x90
+#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
+
+/* Can shift up to 48 bits (6 bytes) of TX/RX */
+#define MTK_NOR_MAX_RX_TX_SHIFT		6
+/* can shift up to 56 bits (7 bytes) transfer by MTK_NOR_PRG_CMD */
+#define MTK_NOR_MAX_SHIFT		7
+
+/* Helpers for accessing the program data / shift data registers */
+#define MTK_NOR_PRG_REG(n)		(MTK_NOR_PRGDATA0_REG + 4 * (n))
+#define MTK_NOR_SHREG(n)		(MTK_NOR_SHREG0_REG + 4 * (n))
+
+struct mt8173_nor {
+	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(nor->read_opcode, 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(nor->read_opcode, 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(nor->read_opcode, mt8173_nor->base +
+		       MTK_NOR_PRGDATA4_REG);
+		writeb(MTK_NOR_QUAD_READ_EN, mt8173_nor->base +
+		       MTK_NOR_DUAL_REG);
+		break;
+	default:
+		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_do_tx_rx(struct mt8173_nor *mt8173_nor, u8 op,
+			       u8 *tx, int txlen, u8 *rx, int rxlen)
+{
+	int len = 1 + txlen + rxlen;
+	int i, ret, idx;
+
+	if (len > MTK_NOR_MAX_SHIFT)
+		return -EINVAL;
+
+	writeb(len * 8, mt8173_nor->base + MTK_NOR_CNT_REG);
+
+	/* start at PRGDATA5, go down to PRGDATA0 */
+	idx = MTK_NOR_MAX_RX_TX_SHIFT - 1;
+
+	/* opcode */
+	writeb(op, mt8173_nor->base + MTK_NOR_PRG_REG(idx));
+	idx--;
+
+	/* program TX data */
+	for (i = 0; i < txlen; i++, idx--)
+		writeb(tx[i], mt8173_nor->base + MTK_NOR_PRG_REG(idx));
+
+	/* clear out rest of TX registers */
+	while (idx >= 0) {
+		writeb(0, mt8173_nor->base + MTK_NOR_PRG_REG(idx));
+		idx--;
+	}
+
+	ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_PRG_CMD);
+	if (ret)
+		return ret;
+
+	/* restart at first RX byte */
+	idx = rxlen - 1;
+
+	/* read out RX data */
+	for (i = 0; i < rxlen; i++, idx--)
+		rx[i] = readb(mt8173_nor->base + MTK_NOR_SHREG(idx));
+
+	return 0;
+}
+
+/* Do a WRSR (Write Status Register) command */
+static int mt8173_nor_wr_sr(struct mt8173_nor *mt8173_nor, u8 sr)
+{
+	writeb(sr, mt8173_nor->base + MTK_NOR_PRGDATA5_REG);
+	writeb(8, mt8173_nor->base + MTK_NOR_CNT_REG);
+	return mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_WRSR_CMD);
+}
+
+static int mt8173_nor_write_buffer_enable(struct mt8173_nor *mt8173_nor)
+{
+	u8 reg;
+
+	/* the bit0 of MTK_NOR_CFG2_REG is pre-fetch buffer
+	 * 0: pre-fetch buffer use for read
+	 * 1: pre-fetch buffer use for page program
+	 */
+	writel(MTK_NOR_WR_BUF_ENABLE, mt8173_nor->base + MTK_NOR_CFG2_REG);
+	return readb_poll_timeout(mt8173_nor->base + MTK_NOR_CFG2_REG, reg,
+				  0x01 == (reg & 0x01), 100, 10000);
+}
+
+static int mt8173_nor_write_buffer_disable(struct mt8173_nor *mt8173_nor)
+{
+	u8 reg;
+
+	writel(MTK_NOR_WR_BUF_DISABLE, mt8173_nor->base + MTK_NOR_CFG2_REG);
+	return readb_poll_timeout(mt8173_nor->base + MTK_NOR_CFG2_REG, reg,
+				  MTK_NOR_WR_BUF_DISABLE == (reg & 0x1), 100,
+				  10000);
+}
+
+static void mt8173_nor_set_addr(struct mt8173_nor *mt8173_nor, u32 addr)
+{
+	int i;
+
+	for (i = 0; i < 3; i++) {
+		writeb(addr & 0xff, mt8173_nor->base + MTK_NOR_RADR0_REG + i * 4);
+		addr >>= 8;
+	}
+	/* Last register is non-contiguous */
+	writeb(addr & 0xff, mt8173_nor->base + MTK_NOR_RADR3_REG);
+}
+
+static int mt8173_nor_read(struct spi_nor *nor, loff_t from, size_t length,
+			   size_t *retlen, u_char *buffer)
+{
+	int i, ret;
+	int addr = (int)from;
+	u8 *buf = (u8 *)buffer;
+	struct mt8173_nor *mt8173_nor = nor->priv;
+
+	/* set mode for fast read mode ,dual mode or quad mode */
+	mt8173_nor_set_read_mode(mt8173_nor);
+	mt8173_nor_set_addr(mt8173_nor, addr);
+
+	for (i = 0; i < length; i++, (*retlen)++) {
+		ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_PIO_READ_CMD);
+		if (ret < 0)
+			return ret;
+		buf[i] = readb(mt8173_nor->base + MTK_NOR_RDATA_REG);
+	}
+	return 0;
+}
+
+static int mt8173_nor_write_single_byte(struct mt8173_nor *mt8173_nor,
+					int addr, int length, u8 *data)
+{
+	int i, ret;
+
+	mt8173_nor_set_addr(mt8173_nor, addr);
+
+	for (i = 0; i < length; i++) {
+		ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_PIO_WR_CMD);
+		if (ret < 0)
+			return ret;
+		writeb(*data++, mt8173_nor->base + MTK_NOR_WDATA_REG);
+	}
+	return 0;
+}
+
+static int mt8173_nor_write_buffer(struct mt8173_nor *mt8173_nor, int addr,
+				   const u8 *buf)
+{
+	int i, bufidx, data;
+
+	mt8173_nor_set_addr(mt8173_nor, addr);
+
+	bufidx = 0;
+	for (i = 0; i < SFLASH_WRBUF_SIZE; i += 4) {
+		data = buf[bufidx + 3]<<24 | buf[bufidx + 2]<<16 |
+		       buf[bufidx + 1]<<8 | buf[bufidx];
+		bufidx += 4;
+		writel(data, mt8173_nor->base + MTK_NOR_PP_DATA_REG);
+	}
+	return mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_WR_CMD);
+}
+
+static void mt8173_nor_write(struct spi_nor *nor, loff_t to, size_t len,
+			     size_t *retlen, const u_char *buf)
+{
+	int ret;
+	struct mt8173_nor *mt8173_nor = nor->priv;
+
+	ret = mt8173_nor_write_buffer_enable(mt8173_nor);
+	if (ret < 0)
+		dev_warn(mt8173_nor->dev, "write buffer enable failed!\n");
+
+	while (len >= SFLASH_WRBUF_SIZE) {
+		ret = mt8173_nor_write_buffer(mt8173_nor, to, buf);
+		if (ret < 0)
+			dev_err(mt8173_nor->dev, "write buffer failed!\n");
+		len -= SFLASH_WRBUF_SIZE;
+		to += SFLASH_WRBUF_SIZE;
+		buf += SFLASH_WRBUF_SIZE;
+		(*retlen) += SFLASH_WRBUF_SIZE;
+	}
+	ret = mt8173_nor_write_buffer_disable(mt8173_nor);
+	if (ret < 0)
+		dev_warn(mt8173_nor->dev, "write buffer disable failed!\n");
+
+	if (len) {
+		ret = mt8173_nor_write_single_byte(mt8173_nor, to, (int)len,
+						   (u8 *)buf);
+		if (ret < 0)
+			dev_err(mt8173_nor->dev, "write single byte failed!\n");
+		(*retlen) += len;
+	}
+}
+
+static int mt8173_nor_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+	int ret;
+	struct mt8173_nor *mt8173_nor = nor->priv;
+
+	switch (opcode) {
+	case SPINOR_OP_RDSR:
+		ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_RDSR_CMD);
+		if (ret < 0)
+			return ret;
+		if (len == 1)
+			*buf = readb(mt8173_nor->base + MTK_NOR_RDSR_REG);
+		else
+			dev_err(mt8173_nor->dev, "len should be 1 for read status!\n");
+		break;
+	default:
+		ret = mt8173_nor_do_tx_rx(mt8173_nor, opcode, NULL, 0, buf, len);
+		break;
+	}
+	return ret;
+}
+
+static int mt8173_nor_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf,
+				int len)
+{
+	int ret;
+	struct mt8173_nor *mt8173_nor = nor->priv;
+
+	switch (opcode) {
+	case SPINOR_OP_WRSR:
+		/* We only handle 1 byte */
+		ret = mt8173_nor_wr_sr(mt8173_nor, *buf);
+		break;
+	default:
+		ret = mt8173_nor_do_tx_rx(mt8173_nor, opcode, buf, len, NULL, 0);
+		if (ret)
+			dev_warn(mt8173_nor->dev, "write reg failure!\n");
+		break;
+	}
+	return ret;
+}
+
+static int __init mtk_nor_init(struct mt8173_nor *mt8173_nor,
+			       struct device_node *flash_node)
+{
+	int ret;
+	struct spi_nor *nor;
+
+	/* initialize controller to accept commands */
+	writel(MTK_NOR_ENABLE_SF_CMD, mt8173_nor->base + MTK_NOR_WRPROT_REG);
+
+	nor = &mt8173_nor->nor;
+	nor->dev = mt8173_nor->dev;
+	nor->priv = mt8173_nor;
+	spi_nor_set_flash_node(nor, flash_node);
+
+	/* fill the hooks to spi nor */
+	nor->read = mt8173_nor_read;
+	nor->read_reg = mt8173_nor_read_reg;
+	nor->write = mt8173_nor_write;
+	nor->write_reg = mt8173_nor_write_reg;
+	nor->mtd.owner = THIS_MODULE;
+	nor->mtd.name = "mtk_nor";
+	/* initialized with NULL */
+	ret = spi_nor_scan(nor, NULL, SPI_NOR_DUAL);
+	if (ret)
+		return ret;
+
+	return mtd_device_register(&nor->mtd, NULL, 0);
+}
+
+static int mtk_nor_drv_probe(struct platform_device *pdev)
+{
+	struct device_node *flash_np;
+	struct resource *res;
+	int ret;
+	struct mt8173_nor *mt8173_nor;
+
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev, "No DT found\n");
+		return -EINVAL;
+	}
+
+	mt8173_nor = devm_kzalloc(&pdev->dev, sizeof(*mt8173_nor), GFP_KERNEL);
+	if (!mt8173_nor)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, mt8173_nor);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mt8173_nor->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(mt8173_nor->base))
+		return PTR_ERR(mt8173_nor->base);
+
+	mt8173_nor->spi_clk = devm_clk_get(&pdev->dev, "spi");
+	if (IS_ERR(mt8173_nor->spi_clk))
+		return PTR_ERR(mt8173_nor->spi_clk);
+
+	mt8173_nor->nor_clk = devm_clk_get(&pdev->dev, "sf");
+	if (IS_ERR(mt8173_nor->nor_clk))
+		return PTR_ERR(mt8173_nor->nor_clk);
+
+	mt8173_nor->dev = &pdev->dev;
+	ret = clk_prepare_enable(mt8173_nor->spi_clk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(mt8173_nor->nor_clk);
+	if (ret) {
+		clk_disable_unprepare(mt8173_nor->spi_clk);
+		return ret;
+	}
+	/* only support one attached flash */
+	flash_np = of_get_next_available_child(pdev->dev.of_node, NULL);
+	if (!flash_np) {
+		dev_err(&pdev->dev, "no SPI flash device to configure\n");
+		ret = -ENODEV;
+		goto nor_free;
+	}
+	ret = mtk_nor_init(mt8173_nor, flash_np);
+
+nor_free:
+	if (ret) {
+		clk_disable_unprepare(mt8173_nor->spi_clk);
+		clk_disable_unprepare(mt8173_nor->nor_clk);
+	}
+	return ret;
+}
+
+static int mtk_nor_drv_remove(struct platform_device *pdev)
+{
+	struct mt8173_nor *mt8173_nor = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(mt8173_nor->spi_clk);
+	clk_disable_unprepare(mt8173_nor->nor_clk);
+	return 0;
+}
+
+static const struct of_device_id mtk_nor_of_ids[] = {
+	{ .compatible = "mediatek,mt8173-nor"},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mtk_nor_of_ids);
+
+static struct platform_driver mtk_nor_driver = {
+	.probe = mtk_nor_drv_probe,
+	.remove = mtk_nor_drv_remove,
+	.driver = {
+		.name = "mtk-nor",
+		.of_match_table = mtk_nor_of_ids,
+	},
+};
+
+module_platform_driver(mtk_nor_driver);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MediaTek SPI NOR Flash Driver");