[Patch v3 2/5] mtd: nand: add NVIDIA Tegra NAND Flash controller driver
From: computersforpeace@gmail.com (Brian Norris)
Date: 2015-07-21 21:27:10
Also in:
linux-devicetree, linux-tegra
Hi Lucas, On Sun, May 10, 2015 at 08:29:59PM +0200, Lucas Stach wrote:
Add support for the NAND flash controller found on NVIDIA Tegra 2/3 SoCs. Signed-off-by: Thierry Reding <redacted> Signed-off-by: Lucas Stach <dev@lynxeye.de> Reviewed-by: Stefan Agner <stefan@agner.ch> --- 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 v3: - remove superfluous NAND cap setting - correct ECC layout - don't flag ECC error for erased pages
^^ So you approached a tricky subject here :) more below
quoted hunk
- make MTD device name a bit human friendlier - mark subpage writes as unsupported - parse BBT on flash property --- MAINTAINERS | 6 + drivers/mtd/nand/Kconfig | 6 + drivers/mtd/nand/Makefile | 1 + drivers/mtd/nand/tegra_nand.c | 801 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 814 insertions(+) create mode 100644 drivers/mtd/nand/tegra_nand.cdiff --git a/MAINTAINERS b/MAINTAINERS index 781e099..7e5551f 100644 --- a/MAINTAINERS +++ b/MAINTAINERS@@ -9747,6 +9747,12 @@ M: Laxman Dewangan <ldewangan@nvidia.com> S: Supported F: drivers/input/keyboard/tegra-kbc.c +TEGRA NAND DRIVER +M: Lucas Stach <dev@lynxeye.de> +S: Maintained +F: Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt +F: drivers/mtd/nand/tegra_nand.c
Thanks for doing this.
quoted hunk
+ TEGRA PWM DRIVER M: Thierry Reding [off-list ref] S: Supporteddiff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig index 5897d8d..2696418 100644 --- a/drivers/mtd/nand/Kconfig +++ b/drivers/mtd/nand/Kconfig@@ -530,4 +530,10 @@ 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
Is this a strict depends? Maybe relax to the following at least: depends on ARCH_TEGRA || COMPILE_TEST
quoted hunk
+ help + Enables support for NAND flash on NVIDIA Tegra SoC based boards. + endif # MTD_NANDdiff --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.odiff --git a/drivers/mtd/nand/tegra_nand.c b/drivers/mtd/nand/tegra_nand.c new file mode 100644 index 0000000..20ea1f1 --- /dev/null +++ b/drivers/mtd/nand/tegra_nand.c@@ -0,0 +1,801 @@ +/* + * Copyright (C) 2014-2015 Lucas Stach <dev@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 = { 4, 5, 6, 7 }, + .oobfree = { + { .offset = 8, . length = 8 } + } +}; + +static struct nand_ecclayout tegra_nand_oob_64 = { + .eccbytes = 36, + .eccpos = { + 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 = { + 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 = { + 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) { + /* + * The ECC isn't smart enough to figure out if a page is + * completely erased and flags an error in this case. So we + * check the read data here to figure out if it's a legitimate + * error or a false positive. + */ + int i; + u32 *data = (u32 *)buf; + for (i = 0; i < mtd->writesize / 4; i++) { + if (data[i] != 0xffffffff) { + mtd->ecc_stats.failed++; + return -EBADMSG; + } + }
Hmm, what about OOB? It's possible to actually write 0xff to the entire page. This hunk means that such a data pattern would then be unprotected. You should probably check that *both* the main and OOB data are all 0xff; if there are non-0xff bytes, then that (probably, see the following) means someone intentionally wrote all 0xff to the page. [1] Also, your check doesn't handle the case of finding bitflips in erased pages. So not only do you need to check for all 0xff, but you also need to tolerate a few flips. e.g., using hweight*() functions. There is plenty of discussion on this subject, as many people have tried to resolve this for their various drivers. But none have really done this in a thorough and correct way, so few have been merged. Thus, I'd really like to get something like this merged to nand_base.c, with a NAND_* flag or two to enable it. That would help drivers like yours to easily grab a good (albeit, likely slow) implementation. So, I'd like to see the first request (about OOB checks) solved, and if the larger bitflips-in-erased-pages issue isn't addressed, please include a FIXME comment, or something similar.
+ return 0;
+ }
+
+ if (value & DEC_STATUS_ERR_COUNT_MASK) {
+ value = (value & DEC_STATUS_ERR_COUNT_MASK) >>
+ DEC_STATUS_ERR_COUNT_SHIFT;What does this ERR_COUNT represent? The total bitflips seen in this page? The max seen per ECC region? Or something else?
+ mtd->ecc_stats.corrected += value;
I ask because this ^^^ should be accounting the total bitflips for the page, if possible...
+ return value;
...and this ^^^ should be returning the max bitflips seen in a single correction region (see the mtd_read() API). There is a subtle difference.
+ }
+
+ 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)
+{This function could use some comments. The math can be easy to get wrong, especially without the annotation of units (e.g., picoseconds). Also, look out for rounding inaccuracies. DIV_ROUND_UP() is nice for getting conservative conversions at times.
+ 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;You could set chip->dn, then nand_dt_init() might capture this for you.
+ + 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 = "tegra_nand"; + mtd->owner = THIS_MODULE; + mtd->priv = &nand->chip; + + /* 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->options = NAND_NO_SUBPAGE_WRITE; + 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; + + if (of_get_nand_on_flash_bbt(pdev->dev.of_node)) + chip->bbt_options = NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
Again, nand_dt_init() might help you. You might then augment it with: if (chip->bbt_options & NAND_BBT_USE_FLASH) chip->bbt_options |= NAND_BBT_NO_OOB;
+
+ 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);Check the return value for errors.
+
+ 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@avionic-design.de");
+MODULE_AUTHOR("Lucas Stach <dev@lynxeye.de");
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(of, tegra_nand_of_match);Thanks, Brian [1] Litmus test: write all 0xff with nandwrite, then read back with nanddump. Do you get 'ECC failed' counts? Now that I think about it, we should probably publish a proper test, either in mtd-utils or drivers/mtd/tests/ to check for this.