[PATCH v2 2/5] mtd: nand: add NVIDIA Tegra NAND Flash controller driver

Lucas Stach dev at lynxeye.de
Wed Apr 8 12:46:07 PDT 2015


Add support for the NAND flash controller found on NVIDIA
Tegra 2/3 SoCs.

Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>
Signed-off-by: Lucas Stach <dev at lynxeye.de>
---
v2:
- remove Tegra 3 compatible
- remove useless part_probes
- don't store irq number
- use gpiod API instead of deprecated of_gpios
- don't store reset
- correct TIMING_TCS mask
- simplify irq handler
- correct timing calculations
- don't store buswidth
- drop compile test
- correct ECC handling
---
 MAINTAINERS                   |   6 +
 drivers/mtd/nand/Kconfig      |   6 +
 drivers/mtd/nand/Makefile     |   1 +
 drivers/mtd/nand/tegra_nand.c | 786 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 799 insertions(+)
 create mode 100644 drivers/mtd/nand/tegra_nand.c

diff --git a/MAINTAINERS b/MAINTAINERS
index ddc5a8c..6c56739 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9641,6 +9641,12 @@ M:	Laxman Dewangan <ldewangan at nvidia.com>
 S:	Supported
 F:	drivers/input/keyboard/tegra-kbc.c
 
+TEGRA NAND DRIVER
+M:	Lucas Stach <dev at lynxeye.de>
+S:	Maintained
+F:	Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
+F:	drivers/mtd/nand/tegra_nand.c
+
 TEGRA PWM DRIVER
 M:	Thierry Reding <thierry.reding at gmail.com>
 S:	Supported
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 5b76a17..86d7c87 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -529,4 +529,10 @@ config MTD_NAND_HISI504
 	help
 	  Enables support for NAND controller on Hisilicon SoC Hip04.
 
+config MTD_NAND_TEGRA
+	tristate "Support for NAND on NVIDIA Tegra"
+	depends on ARCH_TEGRA
+	help
+	  Enables support for NAND flash on NVIDIA Tegra SoC based boards.
+
 endif # MTD_NAND
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 582bbd05..3228e6e 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -52,5 +52,6 @@ obj-$(CONFIG_MTD_NAND_XWAY)		+= xway_nand.o
 obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash/
 obj-$(CONFIG_MTD_NAND_SUNXI)		+= sunxi_nand.o
 obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
+obj-$(CONFIG_MTD_NAND_TEGRA)		+= tegra_nand.o
 
 nand-objs := nand_base.o nand_bbt.o nand_timings.o
diff --git a/drivers/mtd/nand/tegra_nand.c b/drivers/mtd/nand/tegra_nand.c
new file mode 100644
index 0000000..0e42985
--- /dev/null
+++ b/drivers/mtd/nand/tegra_nand.c
@@ -0,0 +1,786 @@
+/*
+ * Copyright (C) 2014-2015 Lucas Stach <dev at lynxeye.de>
+ * Copyright (C) 2012 Avionic Design GmbH
+ *
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of_mtd.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#define CMD				0x00
+#define   CMD_GO			(1 << 31)
+#define   CMD_CLE			(1 << 30)
+#define   CMD_ALE			(1 << 29)
+#define   CMD_PIO			(1 << 28)
+#define   CMD_TX			(1 << 27)
+#define   CMD_RX			(1 << 26)
+#define   CMD_SEC_CMD			(1 << 25)
+#define   CMD_AFT_DAT			(1 << 24)
+#define   CMD_TRANS_SIZE(x)		(((x) & 0xf) << 20)
+#define   CMD_A_VALID			(1 << 19)
+#define   CMD_B_VALID			(1 << 18)
+#define   CMD_RD_STATUS_CHK		(1 << 17)
+#define   CMD_RBSY_CHK			(1 << 16)
+#define   CMD_CE(x)			(1 << (8 + ((x) & 0x7)))
+#define   CMD_CLE_SIZE(x)		(((x) & 0x3) << 4)
+#define   CMD_ALE_SIZE(x)		(((x) & 0xf) << 0)
+
+#define STATUS				0x04
+
+#define ISR				0x08
+#define   ISR_UND			(1 << 7)
+#define   ISR_OVR			(1 << 6)
+#define   ISR_CMD_DONE			(1 << 5)
+#define   ISR_ECC_ERR			(1 << 4)
+
+#define IER				0x0c
+#define   IER_ERR_TRIG_VAL(x)		(((x) & 0xf) << 16)
+#define   IER_UND			(1 << 7)
+#define   IER_OVR			(1 << 6)
+#define   IER_CMD_DONE			(1 << 5)
+#define   IER_ECC_ERR			(1 << 4)
+#define   IER_GIE			(1 << 0)
+
+#define CFG				0x10
+#define   CFG_HW_ECC			(1 << 31)
+#define   CFG_ECC_SEL			(1 << 30)
+#define   CFG_ERR_COR			(1 << 29)
+#define   CFG_PIPE_EN			(1 << 28)
+#define   CFG_TVAL_4			(0 << 24)
+#define   CFG_TVAL_6			(1 << 24)
+#define   CFG_TVAL_8			(2 << 24)
+#define   CFG_SKIP_SPARE		(1 << 23)
+#define   CFG_BUS_WIDTH_8		(0 << 21)
+#define   CFG_BUS_WIDTH_16		(1 << 21)
+#define   CFG_COM_BSY			(1 << 20)
+#define   CFG_PS_256			(0 << 16)
+#define   CFG_PS_512			(1 << 16)
+#define   CFG_PS_1024			(2 << 16)
+#define   CFG_PS_2048			(3 << 16)
+#define   CFG_PS_4096			(4 << 16)
+#define   CFG_SKIP_SPARE_SIZE_4		(0 << 14)
+#define   CFG_SKIP_SPARE_SIZE_8		(1 << 14)
+#define   CFG_SKIP_SPARE_SIZE_12	(2 << 14)
+#define   CFG_SKIP_SPARE_SIZE_16	(3 << 14)
+#define   CFG_TAG_BYTE_SIZE(x)		((x) & 0xff)
+
+#define TIMING_1			0x14
+#define   TIMING_TRP_RESP(x)		(((x) & 0xf) << 28)
+#define   TIMING_TWB(x)			(((x) & 0xf) << 24)
+#define   TIMING_TCR_TAR_TRR(x)		(((x) & 0xf) << 20)
+#define   TIMING_TWHR(x)		(((x) & 0xf) << 16)
+#define   TIMING_TCS(x)			(((x) & 0x3) << 14)
+#define   TIMING_TWH(x)			(((x) & 0x3) << 12)
+#define   TIMING_TWP(x)			(((x) & 0xf) <<  8)
+#define   TIMING_TRH(x)			(((x) & 0xf) <<  4)
+#define   TIMING_TRP(x)			(((x) & 0xf) <<  0)
+
+#define RESP				0x18
+
+#define TIMING_2			0x1c
+#define   TIMING_TADL(x)		((x) & 0xf)
+
+#define CMD_1				0x20
+#define CMD_2				0x24
+#define ADDR_1				0x28
+#define ADDR_2				0x2c
+
+#define DMA_CTRL			0x30
+#define   DMA_CTRL_GO			(1 << 31)
+#define   DMA_CTRL_IN			(0 << 30)
+#define   DMA_CTRL_OUT			(1 << 30)
+#define   DMA_CTRL_PERF_EN		(1 << 29)
+#define   DMA_CTRL_IE_DONE		(1 << 28)
+#define   DMA_CTRL_REUSE		(1 << 27)
+#define   DMA_CTRL_BURST_1		(2 << 24)
+#define   DMA_CTRL_BURST_4		(3 << 24)
+#define   DMA_CTRL_BURST_8		(4 << 24)
+#define   DMA_CTRL_BURST_16		(5 << 24)
+#define   DMA_CTRL_IS_DONE		(1 << 20)
+#define   DMA_CTRL_EN_A			(1 <<  2)
+#define   DMA_CTRL_EN_B			(1 <<  1)
+
+#define DMA_CFG_A			0x34
+#define DMA_CFG_B			0x38
+
+#define FIFO_CTRL			0x3c
+#define   FIFO_CTRL_CLR_ALL		(1 << 3)
+
+#define DATA_PTR			0x40
+#define TAG_PTR				0x44
+#define ECC_PTR				0x48
+
+#define DEC_STATUS			0x4c
+#define   DEC_STATUS_A_ECC_FAIL		(1 << 1)
+#define   DEC_STATUS_ERR_COUNT_MASK	0x00ff0000
+#define   DEC_STATUS_ERR_COUNT_SHIFT	16
+
+#define HWSTATUS_CMD			0x50
+#define HWSTATUS_MASK			0x54
+#define   HWSTATUS_RDSTATUS_MASK(x)	(((x) & 0xff) << 24)
+#define   HWSTATUS_RDSTATUS_VALUE(x)	(((x) & 0xff) << 16)
+#define   HWSTATUS_RBSY_MASK(x)		(((x) & 0xff) << 8)
+#define   HWSTATUS_RBSY_VALUE(x)	(((x) & 0xff) << 0)
+
+struct tegra_nand {
+	void __iomem *regs;
+	struct clk *clk;
+	struct gpio_desc *wp_gpio;
+
+	struct nand_chip chip;
+	struct mtd_info mtd;
+	struct device *dev;
+
+	struct completion command_complete;
+	struct completion dma_complete;
+
+	dma_addr_t data_dma;
+	void *data_buf;
+	dma_addr_t oob_dma;
+	void *oob_buf;
+
+	int cur_chip;
+};
+
+static inline struct tegra_nand *to_tegra_nand(struct mtd_info *mtd)
+{
+	return container_of(mtd, struct tegra_nand, mtd);
+}
+
+static struct nand_ecclayout tegra_nand_oob_16 = {
+	.eccbytes = 4,
+	.eccpos = { 3, 4, 5, 6 },
+	.oobfree = {
+		{ .offset = 7, . length = 8 }
+	}
+};
+
+static struct nand_ecclayout tegra_nand_oob_64 = {
+	.eccbytes = 36,
+	.eccpos = {
+		 3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
+		19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,
+		35, 36, 37, 38, 39
+	},
+	.oobfree = {
+		{ .offset = 40, .length = 24 }
+	}
+};
+
+static struct nand_ecclayout tegra_nand_oob_128 = {
+	.eccbytes = 72,
+	.eccpos = {
+		 3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
+		19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,
+		35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50,
+		51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66,
+		67, 68, 69, 70, 71, 72, 73, 74, 75
+	},
+	.oobfree = {
+		{ .offset = 76, .length = 52 }
+	}
+};
+
+static struct nand_ecclayout tegra_nand_oob_224 = {
+	.eccbytes = 144,
+	.eccpos = {
+		  3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
+		 15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,
+		 27,  28,  29,  30,  31,  32,  33,  34,  35,  36,  37,  38,
+		 39,  40,  41,  42,  43,  44,  45,  46,  47,  48,  49,  50,
+		 51,  52,  53,  54,  55,  56,  57,  58,  59,  60,  61,  62,
+		 63,  64,  65,  66,  67,  68,  69,  70,  71,  72,  73,  74,
+		 75,  76,  77,  78,  79,  80,  81,  82,  83,  84,  85,  86,
+		 87,  88,  89,  90,  91,  92,  93,  94,  95,  96,  97,  98,
+		 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110,
+		111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122,
+		123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134,
+		135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146,
+		147
+	},
+	.oobfree = {
+		{ .offset = 148, .length = 76 }
+	}
+};
+
+static irqreturn_t tegra_nand_irq(int irq, void *data)
+{
+	struct tegra_nand *nand = data;
+	u32 isr, dma;
+
+	isr = readl(nand->regs + ISR);
+	dma = readl(nand->regs + DMA_CTRL);
+
+	if (!isr && !(dma & DMA_CTRL_IS_DONE))
+		return IRQ_NONE;
+
+	if (isr & ISR_CMD_DONE)
+		complete(&nand->command_complete);
+
+	if (isr & ISR_UND)
+		dev_dbg(nand->dev, "FIFO underrun\n");
+
+	if (isr & ISR_OVR)
+		dev_dbg(nand->dev, "FIFO overrun\n");
+
+	/* handle DMA interrupts */
+	if (dma & DMA_CTRL_IS_DONE) {
+		writel(dma, nand->regs + DMA_CTRL);
+		complete(&nand->dma_complete);
+	}
+
+	/* clear interrupts */
+	writel(isr, nand->regs + ISR);
+
+	return IRQ_HANDLED;
+}
+
+static void tegra_nand_command(struct mtd_info *mtd, unsigned int command,
+			       int column, int page_addr)
+{
+	struct tegra_nand *nand = to_tegra_nand(mtd);
+	u32 value;
+
+	switch (command) {
+	case NAND_CMD_READOOB:
+		column += mtd->writesize;
+		/* fall-through */
+
+	case NAND_CMD_READ0:
+		writel(NAND_CMD_READ0, nand->regs + CMD_1);
+		writel(NAND_CMD_READSTART, nand->regs + CMD_2);
+
+		value = (page_addr << 16) | (column & 0xffff);
+		writel(value, nand->regs + ADDR_1);
+
+		value = page_addr >> 16;
+		writel(value, nand->regs + ADDR_2);
+
+		value = CMD_CLE | CMD_ALE | CMD_ALE_SIZE(4) | CMD_SEC_CMD |
+			CMD_RBSY_CHK | CMD_CE(nand->cur_chip) | CMD_GO;
+		writel(value, nand->regs + CMD);
+		break;
+
+	case NAND_CMD_SEQIN:
+		writel(NAND_CMD_SEQIN, nand->regs + CMD_1);
+
+		value = (page_addr << 16) | (column & 0xffff);
+		writel(value, nand->regs + ADDR_1);
+
+		value = page_addr >> 16;
+		writel(value, nand->regs + ADDR_2);
+
+		value = CMD_CLE | CMD_ALE | CMD_ALE_SIZE(4) |
+			CMD_CE(nand->cur_chip) | CMD_GO;
+		writel(value, nand->regs + CMD);
+		break;
+
+	case NAND_CMD_PAGEPROG:
+		writel(NAND_CMD_PAGEPROG, nand->regs + CMD_1);
+
+		value = CMD_CLE | CMD_CE(nand->cur_chip) | CMD_GO;
+		writel(value, nand->regs + CMD);
+		break;
+
+	case NAND_CMD_READID:
+		writel(NAND_CMD_READID, nand->regs + CMD_1);
+		writel(column & 0xff, nand->regs + ADDR_1);
+
+		value = CMD_GO | CMD_CLE | CMD_ALE | CMD_CE(nand->cur_chip);
+		writel(value, nand->regs + CMD);
+		break;
+
+	case NAND_CMD_ERASE1:
+		writel(NAND_CMD_ERASE1, nand->regs + CMD_1);
+		writel(NAND_CMD_ERASE2, nand->regs + CMD_2);
+		writel(page_addr, nand->regs + ADDR_1);
+
+		value = CMD_GO | CMD_CLE | CMD_ALE | CMD_ALE_SIZE(2) |
+			CMD_SEC_CMD | CMD_RBSY_CHK | CMD_CE(nand->cur_chip);
+		writel(value, nand->regs + CMD);
+		break;
+
+	case NAND_CMD_ERASE2:
+		return;
+
+	case NAND_CMD_STATUS:
+		writel(NAND_CMD_STATUS, nand->regs + CMD_1);
+
+		value = CMD_GO | CMD_CLE | CMD_CE(nand->cur_chip);
+		writel(value, nand->regs + CMD);
+		break;
+
+	case NAND_CMD_PARAM:
+		writel(NAND_CMD_PARAM, nand->regs + CMD_1);
+		writel(column & 0xff, nand->regs + ADDR_1);
+		value = CMD_GO | CMD_CLE | CMD_ALE | CMD_CE(nand->cur_chip);
+		writel(value, nand->regs + CMD);
+		break;
+
+	case NAND_CMD_RESET:
+		writel(NAND_CMD_RESET, nand->regs + CMD_1);
+
+		value = CMD_GO | CMD_CLE | CMD_CE(nand->cur_chip);
+		writel(value, nand->regs + CMD);
+		break;
+
+	default:
+		dev_warn(nand->dev, "unsupported command: %x\n", command);
+		return;
+	}
+
+	wait_for_completion(&nand->command_complete);
+}
+
+static void tegra_nand_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct tegra_nand *nand = to_tegra_nand(mtd);
+
+	nand->cur_chip = chip;
+}
+
+static uint8_t tegra_nand_read_byte(struct mtd_info *mtd)
+{
+	struct tegra_nand *nand = to_tegra_nand(mtd);
+	u32 value;
+
+	value = CMD_TRANS_SIZE(0) | CMD_CE(nand->cur_chip) |
+		CMD_PIO | CMD_RX | CMD_A_VALID | CMD_GO;
+
+	writel(value, nand->regs + CMD);
+	wait_for_completion(&nand->command_complete);
+
+	return readl(nand->regs + RESP) & 0xff;
+}
+
+static void tegra_nand_read_buf(struct mtd_info *mtd, uint8_t *buffer,
+				int length)
+{
+	struct tegra_nand *nand = to_tegra_nand(mtd);
+	size_t i;
+
+	for (i = 0; i < length; i += 4) {
+		u32 value;
+		size_t n = min_t(size_t, length - i, 4);
+
+		value = CMD_GO | CMD_PIO | CMD_RX | CMD_A_VALID |
+			CMD_CE(nand->cur_chip) | CMD_TRANS_SIZE(n - 1);
+
+		writel(value, nand->regs + CMD);
+		wait_for_completion(&nand->command_complete);
+
+		value = readl(nand->regs + RESP);
+		memcpy(buffer + i, &value, n);
+	}
+}
+
+static void tegra_nand_write_buf(struct mtd_info *mtd, const uint8_t *buffer,
+				 int length)
+{
+	struct tegra_nand *nand = to_tegra_nand(mtd);
+	size_t i;
+
+	for (i = 0; i < length; i += 4) {
+		u32 value;
+		size_t n = min_t(size_t, length - i, 4);
+
+		memcpy(&value, buffer + i, n);
+		writel(value, nand->regs + RESP);
+
+		value = CMD_GO | CMD_PIO | CMD_TX | CMD_A_VALID |
+			CMD_CE(nand->cur_chip) | CMD_TRANS_SIZE(n - 1);
+
+		writel(value, nand->regs + CMD);
+		wait_for_completion(&nand->command_complete);
+	}
+}
+
+static int tegra_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
+				uint8_t *buf, int oob_required, int page)
+{
+	struct tegra_nand *nand = to_tegra_nand(mtd);
+	u32 value;
+
+	value = readl(nand->regs + CFG);
+	value |= CFG_HW_ECC | CFG_ERR_COR;
+	writel(value, nand->regs + CFG);
+
+	writel(mtd->writesize - 1, nand->regs + DMA_CFG_A);
+	writel(nand->data_dma, nand->regs + DATA_PTR);
+
+	if (oob_required) {
+		writel(mtd->oobsize - 1, nand->regs + DMA_CFG_B);
+		writel(nand->oob_dma, nand->regs + TAG_PTR);
+	} else {
+		writel(0, nand->regs + DMA_CFG_B);
+		writel(0, nand->regs + TAG_PTR);
+	}
+
+	value = DMA_CTRL_GO | DMA_CTRL_IN | DMA_CTRL_PERF_EN |
+		DMA_CTRL_REUSE | DMA_CTRL_IE_DONE | DMA_CTRL_IS_DONE |
+		DMA_CTRL_BURST_8 | DMA_CTRL_EN_A;
+
+	if (oob_required)
+		value |= DMA_CTRL_EN_B;
+
+	writel(value, nand->regs + DMA_CTRL);
+
+	value = CMD_GO | CMD_RX | CMD_TRANS_SIZE(8) |
+		CMD_A_VALID | CMD_CE(nand->cur_chip);
+	if (oob_required)
+		value |= CMD_B_VALID;
+	writel(value, nand->regs + CMD);
+
+	wait_for_completion(&nand->command_complete);
+	wait_for_completion(&nand->dma_complete);
+
+	if (oob_required)
+		memcpy(chip->oob_poi, nand->oob_buf, mtd->oobsize);
+	memcpy(buf, nand->data_buf, mtd->writesize);
+
+	value = readl(nand->regs + CFG);
+	value &= ~(CFG_HW_ECC | CFG_ERR_COR);
+	writel(value, nand->regs + CFG);
+
+	value = readl(nand->regs + DEC_STATUS);
+	if (value & DEC_STATUS_A_ECC_FAIL) {
+		mtd->ecc_stats.failed++;
+		return -EBADMSG;
+	}
+	if (value & DEC_STATUS_ERR_COUNT_MASK) {
+		value = (value & DEC_STATUS_ERR_COUNT_MASK) >>
+			DEC_STATUS_ERR_COUNT_SHIFT;
+		mtd->ecc_stats.corrected += value;
+		return value;
+	}
+
+	return 0;
+}
+
+static int tegra_nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+				 const uint8_t *buf, int oob_required)
+{
+	struct tegra_nand *nand = to_tegra_nand(mtd);
+	unsigned long value;
+
+	value = readl(nand->regs + CFG);
+	value |= CFG_HW_ECC | CFG_ERR_COR;
+	writel(value, nand->regs + CFG);
+
+	memcpy(nand->data_buf, buf, mtd->writesize);
+
+	writel(mtd->writesize - 1, nand->regs + DMA_CFG_A);
+	writel(nand->data_dma, nand->regs + DATA_PTR);
+
+	writel(0, nand->regs + DMA_CFG_B);
+	writel(0, nand->regs + TAG_PTR);
+
+	value = DMA_CTRL_GO | DMA_CTRL_OUT | DMA_CTRL_PERF_EN |
+		DMA_CTRL_IE_DONE | DMA_CTRL_IS_DONE |
+		DMA_CTRL_BURST_8 | DMA_CTRL_EN_A;
+	writel(value, nand->regs + DMA_CTRL);
+
+	value = CMD_GO | CMD_TX | CMD_A_VALID | CMD_TRANS_SIZE(8) |
+		CMD_CE(nand->cur_chip);
+	writel(value, nand->regs + CMD);
+
+	wait_for_completion(&nand->command_complete);
+	wait_for_completion(&nand->dma_complete);
+
+	value = readl(nand->regs + CFG);
+	value &= ~(CFG_HW_ECC | CFG_ERR_COR);
+	writel(value, nand->regs + CFG);
+
+	return 0;
+}
+
+static void tegra_nand_setup_timing(struct tegra_nand *nand, int mode)
+{
+	unsigned long rate = clk_get_rate(nand->clk) / 1000000;
+	unsigned long period = 1000000 / rate;
+	const struct nand_sdr_timings *timings;
+	u32 val, reg = 0;
+
+	timings = onfi_async_timing_mode_to_sdr_timings(mode);
+
+	val = max3(timings->tAR_min, timings->tRR_min,
+		   timings->tRC_min) / period;
+	if (val > 2)
+		val -= 3;
+	reg |= TIMING_TCR_TAR_TRR(val);
+
+	val = max(max(timings->tCS_min, timings->tCH_min),
+		  max(timings->tALS_min, timings->tALH_min)) / period;
+	if (val > 1)
+		val -= 2;
+	reg |= TIMING_TCS(val);
+
+	val = (max(timings->tRP_min, timings->tREA_max) + 6000) / period;
+	reg |= (TIMING_TRP(val) | TIMING_TRP_RESP(val));
+
+	reg |= TIMING_TWB(timings->tWB_max / period);
+	reg |= TIMING_TWHR(timings->tWHR_min / period);
+	reg |= TIMING_TWH(timings->tWH_min / period);
+	reg |= TIMING_TWP(timings->tWP_min / period);
+	reg |= TIMING_TRH(timings->tRHW_min / period);
+
+	writel(reg, nand->regs + TIMING_1);
+
+	val = timings->tADL_min / period;
+	if (val > 2)
+		val -= 3;
+	reg = TIMING_TADL(val);
+
+	writel(reg, nand->regs + TIMING_2);
+}
+
+static void tegra_nand_setup_chiptiming(struct tegra_nand *nand)
+{
+	struct nand_chip *chip = &nand->chip;
+	int mode;
+
+	mode = onfi_get_async_timing_mode(chip);
+	if (mode == ONFI_TIMING_MODE_UNKNOWN)
+		mode = chip->onfi_timing_mode_default;
+	else
+		mode = fls(mode);
+
+	tegra_nand_setup_timing(nand, mode);
+}
+
+static int tegra_nand_probe(struct platform_device *pdev)
+{
+	struct reset_control *rst;
+	struct tegra_nand *nand;
+	struct nand_chip *chip;
+	struct mtd_info *mtd;
+	struct resource *res;
+	unsigned long value;
+	int irq, buswidth, err = 0;
+
+	nand = devm_kzalloc(&pdev->dev, sizeof(*nand), GFP_KERNEL);
+	if (!nand)
+		return -ENOMEM;
+
+	nand->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	nand->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(nand->regs))
+		return PTR_ERR(nand->regs);
+
+	irq = platform_get_irq(pdev, 0);
+	err = devm_request_irq(&pdev->dev, irq, tegra_nand_irq, 0,
+			       dev_name(&pdev->dev), nand);
+	if (err)
+		return err;
+
+	rst = devm_reset_control_get(&pdev->dev, "nand");
+	if (IS_ERR(rst))
+		return PTR_ERR(rst);
+
+	nand->clk = devm_clk_get(&pdev->dev, "nand");
+	if (IS_ERR(nand->clk))
+		return PTR_ERR(nand->clk);
+
+	nand->wp_gpio = gpiod_get_optional(&pdev->dev, "nvidia,wp-gpios",
+					   GPIOD_OUT_HIGH);
+	if (IS_ERR(nand->wp_gpio))
+		return PTR_ERR(nand->wp_gpio);
+
+	buswidth = of_get_nand_bus_width(pdev->dev.of_node);
+	if (buswidth < 0)
+		return buswidth;
+
+	err = clk_prepare_enable(nand->clk);
+	if (err)
+		return err;
+
+	reset_control_assert(rst);
+	udelay(2);
+	reset_control_deassert(rst);
+
+	value = HWSTATUS_RDSTATUS_MASK(1) | HWSTATUS_RDSTATUS_VALUE(0) |
+		HWSTATUS_RBSY_MASK(NAND_STATUS_READY) |
+		HWSTATUS_RBSY_VALUE(NAND_STATUS_READY);
+	writel(NAND_CMD_STATUS, nand->regs + HWSTATUS_CMD);
+	writel(value, nand->regs + HWSTATUS_MASK);
+
+	init_completion(&nand->command_complete);
+	init_completion(&nand->dma_complete);
+
+	mtd = &nand->mtd;
+	mtd->name = dev_name(&pdev->dev);
+	mtd->owner = THIS_MODULE;
+	mtd->priv = &nand->chip;
+
+	mtd->type = MTD_NANDFLASH;
+	mtd->flags = MTD_CAP_NANDFLASH;
+
+	/* clear interrupts */
+	value = readl(nand->regs + ISR);
+	writel(value, nand->regs + ISR);
+
+	writel(DMA_CTRL_IS_DONE, nand->regs + DMA_CTRL);
+
+	/* enable interrupts */
+	value = IER_UND | IER_OVR | IER_CMD_DONE | IER_ECC_ERR | IER_GIE;
+	writel(value, nand->regs + IER);
+
+	value = 0;
+	if (buswidth == 16)
+		value |= CFG_BUS_WIDTH_16;
+	writel(value, nand->regs + CFG);
+
+	chip = &nand->chip;
+	chip->cmdfunc = tegra_nand_command;
+	chip->select_chip = tegra_nand_select_chip;
+	chip->read_byte = tegra_nand_read_byte;
+	chip->read_buf = tegra_nand_read_buf;
+	chip->write_buf = tegra_nand_write_buf;
+
+	tegra_nand_setup_timing(nand, 0);
+
+	err = nand_scan_ident(mtd, 1, NULL);
+	if (err)
+		return err;
+
+	nand->data_buf = dmam_alloc_coherent(&pdev->dev, mtd->writesize,
+					    &nand->data_dma, GFP_KERNEL);
+	if (!nand->data_buf)
+		return -ENOMEM;
+
+	nand->oob_buf = dmam_alloc_coherent(&pdev->dev, mtd->oobsize,
+					    &nand->oob_dma, GFP_KERNEL);
+	if (!nand->oob_buf)
+		return -ENOMEM;
+
+	chip->ecc.mode = NAND_ECC_HW;
+	chip->ecc.size = 512;
+	chip->ecc.bytes = mtd->oobsize;
+	chip->ecc.read_page = tegra_nand_read_page;
+	chip->ecc.write_page = tegra_nand_write_page;
+
+	value = readl(nand->regs + CFG);
+	value |=  CFG_PIPE_EN | CFG_SKIP_SPARE | CFG_SKIP_SPARE_SIZE_4;
+
+	switch (mtd->oobsize) {
+	case 16:
+		chip->ecc.layout = &tegra_nand_oob_16;
+		chip->ecc.strength = 1;
+		value |= CFG_TAG_BYTE_SIZE(tegra_nand_oob_16.oobfree[0].length
+			 - 1);
+		break;
+	case 64:
+		chip->ecc.layout = &tegra_nand_oob_64;
+		chip->ecc.strength = 8;
+		value |= CFG_ECC_SEL | CFG_TVAL_8 |
+			 CFG_TAG_BYTE_SIZE(tegra_nand_oob_64.oobfree[0].length
+			 - 1);
+		break;
+	case 128:
+		chip->ecc.layout = &tegra_nand_oob_128;
+		chip->ecc.strength = 8;
+		value |= CFG_ECC_SEL | CFG_TVAL_8 |
+			 CFG_TAG_BYTE_SIZE(tegra_nand_oob_128.oobfree[0].length
+			 - 1);
+		break;
+	case 224:
+		chip->ecc.layout = &tegra_nand_oob_224;
+		chip->ecc.strength = 8;
+		value |= CFG_ECC_SEL | CFG_TVAL_8 |
+			 CFG_TAG_BYTE_SIZE(tegra_nand_oob_224.oobfree[0].length
+			 - 1);
+		break;
+	default:
+		dev_err(&pdev->dev, "unhandled OOB size %d\n", mtd->oobsize);
+		return -ENODEV;
+	}
+
+	switch (mtd->writesize) {
+	case 256:
+		value |= CFG_PS_256;
+		break;
+	case 512:
+		value |= CFG_PS_512;
+		break;
+	case 1024:
+		value |= CFG_PS_1024;
+		break;
+	case 2048:
+		value |= CFG_PS_2048;
+		break;
+	case 4096:
+		value |= CFG_PS_4096;
+		break;
+	default:
+		dev_err(&pdev->dev, "unhandled writesize %d\n", mtd->writesize);
+		return -ENODEV;
+	}
+
+	writel(value, nand->regs + CFG);
+
+	tegra_nand_setup_chiptiming(nand);
+
+	err = nand_scan_tail(mtd);
+	if (err)
+		return err;
+
+	mtd_device_parse_register(mtd, NULL,
+				  &(struct mtd_part_parser_data) {
+					.of_node = pdev->dev.of_node,
+				  },
+				  NULL, 0);
+
+	platform_set_drvdata(pdev, nand);
+
+	return 0;
+}
+
+static int tegra_nand_remove(struct platform_device *pdev)
+{
+	struct tegra_nand *nand = platform_get_drvdata(pdev);
+
+	nand_release(&nand->mtd);
+
+	clk_disable_unprepare(nand->clk);
+
+	return 0;
+}
+
+static const struct of_device_id tegra_nand_of_match[] = {
+	{ .compatible = "nvidia,tegra20-nand" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver tegra_nand_driver = {
+	.driver = {
+		.name = "tegra-nand",
+		.of_match_table = tegra_nand_of_match,
+	},
+	.probe = tegra_nand_probe,
+	.remove = tegra_nand_remove,
+};
+module_platform_driver(tegra_nand_driver);
+
+MODULE_DESCRIPTION("NVIDIA Tegra NAND driver");
+MODULE_AUTHOR("Thierry Reding <thierry.reding at avionic-design.de");
+MODULE_AUTHOR("Lucas Stach <dev at lynxeye.de");
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(of, tegra_nand_of_match);
-- 
2.1.0




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