Re: [PATCH v2 2/2] mtd: nand: Add support for Arasan Nand Flash Controller

From: punnaiah choudary kalluri
Date: Wed May 20 2015 - 23:22:40 EST

On Thu, May 21, 2015 at 2:19 AM, Brian Norris
<computersforpeace@xxxxxxxxx> wrote:
> On Tue, May 19, 2015 at 07:19:17PM +0530, Punnaiah Choudary Kalluri wrote:
>> Added the basic driver for Arasan Nand Flash Controller used in
>> Zynq UltraScale+ MPSoC. It supports only Hw Ecc and upto 24bit
>> correction.
>>
>> Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xxxxxxxxxx>
>> Tested-by: Michal Simek <michal.simek@xxxxxxxxxx>
>> ---
>> Changes in v2:
>> - Added missing of.h to avoid kbuild system report error
>> ---
>> drivers/mtd/nand/Kconfig | 7 +
>> drivers/mtd/nand/Makefile | 1 +
>> drivers/mtd/nand/arasan_nfc.c | 862 +++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 870 insertions(+), 0 deletions(-)
>> create mode 100644 drivers/mtd/nand/arasan_nfc.c
>>
>> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
>> index 5897d8d..64e497c 100644
>> --- a/drivers/mtd/nand/Kconfig
>> +++ b/drivers/mtd/nand/Kconfig
>> @@ -530,4 +530,11 @@ config MTD_NAND_HISI504
>> help
>> Enables support for NAND controller on Hisilicon SoC Hip04.
>>
>> +config MTD_NAND_ARASAN
>> + tristate "Support for Arasan Nand Flash controller"
>> + depends on MTD_NAND
>> + help
>> + Enables the driver for the Arasan Nand Flash controller on
>> + Zynq UltraScale+ MPSoC.
>> +
>> endif # MTD_NAND
>> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
>> index 582bbd05..fd863ea 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_ARASAN) += arasan_nfc.o
>>
>> nand-objs := nand_base.o nand_bbt.o nand_timings.o
>> diff --git a/drivers/mtd/nand/arasan_nfc.c b/drivers/mtd/nand/arasan_nfc.c
>> new file mode 100644
>> index 0000000..5736864
>> --- /dev/null
>> +++ b/drivers/mtd/nand/arasan_nfc.c
>> @@ -0,0 +1,862 @@
>> +/*
>> + * Arasan Nand Flash Controller Driver
>> + *
>> + * Copyright (C) 2014 - 2015 Xilinx, Inc.
>> + *
>> + * 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; either version 2 of the License, or (at your
>> + * option) any later version.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/module.h>
>> +#include <linux/mtd/mtd.h>
>> +#include <linux/mtd/nand.h>
>> +#include <linux/mtd/partitions.h>
>> +#include <linux/of.h>
>> +#include <linux/of_mtd.h>
>> +#include <linux/platform_device.h>
>> +
>> +#define DRIVER_NAME "arasan_nfc"
>> +#define EVNT_TIMEOUT 1000
>> +#define STATUS_TIMEOUT 2000
>> +
>> +#define PKT_OFST 0x00
>> +#define MEM_ADDR1_OFST 0x04
>> +#define MEM_ADDR2_OFST 0x08
>> +#define CMD_OFST 0x0C
>> +#define PROG_OFST 0x10
>> +#define INTR_STS_EN_OFST 0x14
>> +#define INTR_SIG_EN_OFST 0x18
>> +#define INTR_STS_OFST 0x1C
>> +#define READY_STS_OFST 0x20
>> +#define DMA_ADDR1_OFST 0x24
>> +#define FLASH_STS_OFST 0x28
>> +#define DATA_PORT_OFST 0x30
>> +#define ECC_OFST 0x34
>> +#define ECC_ERR_CNT_OFST 0x38
>> +#define ECC_SPR_CMD_OFST 0x3C
>> +#define ECC_ERR_CNT_1BIT_OFST 0x40
>> +#define ECC_ERR_CNT_2BIT_OFST 0x44
>> +#define DMA_ADDR0_OFST 0x50
>> +
>> +#define PKT_CNT_SHIFT 12
>> +
>> +#define ECC_ENABLE BIT(31)
>> +#define DMA_EN_MASK GENMASK(27, 26)
>> +#define DMA_ENABLE 0x2
>> +#define DMA_EN_SHIFT 26
>> +#define PAGE_SIZE_MASK GENMASK(25, 23)
>> +#define PAGE_SIZE_SHIFT 23
>> +#define PAGE_SIZE_512 0
>> +#define PAGE_SIZE_1K 5
>> +#define PAGE_SIZE_2K 1
>> +#define PAGE_SIZE_4K 2
>> +#define PAGE_SIZE_8K 3
>> +#define PAGE_SIZE_16K 4
>> +#define CMD2_SHIFT 8
>> +#define ADDR_CYCLES_SHIFT 28
>> +
>> +#define XFER_COMPLETE BIT(2)
>> +#define READ_READY BIT(1)
>> +#define WRITE_READY BIT(0)
>> +#define MBIT_ERROR BIT(3)
>> +#define ERR_INTRPT BIT(4)
>> +
>> +#define PROG_PGRD BIT(0)
>> +#define PROG_ERASE BIT(2)
>> +#define PROG_STATUS BIT(3)
>> +#define PROG_PGPROG BIT(4)
>> +#define PROG_RDID BIT(6)
>> +#define PROG_RDPARAM BIT(7)
>> +#define PROG_RST BIT(8)
>> +
>> +#define ONFI_STATUS_FAIL BIT(0)
>> +#define ONFI_STATUS_READY BIT(6)
>> +
>> +#define PG_ADDR_SHIFT 16
>> +#define BCH_MODE_SHIFT 25
>> +#define BCH_EN_SHIFT 27
>> +#define ECC_SIZE_SHIFT 16
>> +
>> +#define MEM_ADDR_MASK GENMASK(7, 0)
>> +#define BCH_MODE_MASK GENMASK(27, 25)
>> +
>> +#define CS_MASK GENMASK(31, 30)
>> +#define CS_SHIFT 30
>> +
>> +#define PAGE_ERR_CNT_MASK GENMASK(16, 8)
>> +#define PKT_ERR_CNT_MASK GENMASK(7, 0)
>> +
>> +#define ONFI_ID_LEN 8
>> +#define TEMP_BUF_SIZE 512
>> +
>> +/**
>> + * struct anfc_ecc_matrix - Defines ecc information storage format
>> + * @pagesize: Page size in bytes.
>> + * @codeword_size: Code word size information.
>> + * @eccbits: Number of ecc bits.
>> + * @bch: Bch / Hamming mode enable/disable.
>> + * @eccsize: Ecc size information.
>> + */
>> +struct anfc_ecc_matrix {
>> + u32 pagesize;
>> + u32 codeword_size;
>> + u8 eccbits;
>> + u8 bch;
>> + u16 eccsize;
>> +};
>> +
>> +static const struct anfc_ecc_matrix ecc_matrix[] = {
>> + {512, 512, 1, 0, 0x3},
>> + {512, 512, 4, 1, 0x7},
>> + {512, 512, 8, 1, 0xD},
>> + /* 2K byte page */
>> + {2048, 512, 1, 0, 0xC},
>> + {2048, 512, 4, 1, 0x1A},
>> + {2048, 512, 8, 1, 0x34},
>> + {2048, 512, 12, 1, 0x4E},
>> + {2048, 1024, 24, 1, 0x54},
>> + /* 4K byte page */
>> + {4096, 512, 1, 0, 0x18},
>> + {4096, 512, 4, 1, 0x34},
>> + {4096, 512, 8, 1, 0x68},
>> + {4096, 512, 12, 1, 0x9C},
>> + {4096, 1024, 4, 1, 0xA8},
>> + /* 8K byte page */
>> + {8192, 512, 1, 0, 0x30},
>> + {8192, 512, 4, 1, 0x68},
>> + {8192, 512, 8, 1, 0xD0},
>> + {8192, 512, 12, 1, 0x138},
>> + {8192, 1024, 24, 1, 0x150},
>> + /* 16K byte page */
>> + {16384, 512, 1, 0, 0x60},
>> + {16384, 512, 4, 1, 0xD0},
>> + {16384, 512, 8, 1, 0x1A0},
>> + {16384, 512, 12, 1, 0x270},
>> + {16384, 1024, 24, 1, 0x2A0}
>> +};
>> +
>> +/**
>> + * struct anfc - Defines the Arasan NAND flash driver instance
>> + * @chip: NAND chip information structure.
>> + * @mtd: MTD information structure.
>> + * @parts: Pointer to the mtd_partition structure.
>> + * @dev: Pointer to the device structure.
>> + * @base: Virtual address of the NAND flash device.
>> + * @curr_cmd: Current command issued.
>> + * @dma: Dma enable/disable.
>> + * @bch: Bch / Hamming mode enable/disable.
>> + * @err: Error identifier.
>> + * @iswriteoob: Identifies if oob write operation is required.
>> + * @buf: Buffer used for read/write byte operations.
>> + * @raddr_cycles: Row address cycle information.
>> + * @caddr_cycles: Column address cycle information.
>> + * @irq: irq number
>> + * @page: Page address to be use for write oob operations.
>> + * @pktsize: Packet size for read / write operation.
>> + * @bufshift: Variable used for indexing buffer operation
>> + * @rdintrmask: Interrupt mask value for read operation.
>> + * @bufrdy: Completion event for buffer ready.
>> + * @xfercomp: Completion event for transfer complete.
>> + * @ecclayout: Ecc layout object
>> + */
>> +struct anfc {
>> + struct nand_chip chip;
>> + struct mtd_info mtd;
>> + struct mtd_partition *parts;
>
> ^^ This field is unused.

yaa. i will remove

>
>> + struct device *dev;
>> +
>> + void __iomem *base;
>> + int curr_cmd;
>> +
>> + bool dma;
>> + bool bch;
>> + bool err;
>> + bool iswriteoob;
>> +
>> + u8 buf[TEMP_BUF_SIZE];
>> +
>> + u16 raddr_cycles;)
>> + u16 caddr_cycles;
>> +
>> + u32 irq;
>> + u32 page;
>> + u32 pktsize;
>> + u32 bufshift;
>> + u32 rdintrmask;
>> +
>> + struct completion bufrdy;
>> + struct completion xfercomp;
>> + struct nand_ecclayout ecclayout;
>> +};
>> +
>> +static u8 anfc_page(u32 pagesize)
>> +{
>> + switch (pagesize) {
>> + case 512:
>> + return PAGE_SIZE_512;
>> + case 2048:
>> + return PAGE_SIZE_2K;
>> + case 4096:
>> + return PAGE_SIZE_4K;
>> + case 8192:
>> + return PAGE_SIZE_8K;
>> + case 16384:
>> + return PAGE_SIZE_16K;
>> + case 1024:
>> + return PAGE_SIZE_1K;
>> + default:
>> + break;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static inline void anfc_enable_intrs(struct anfc *nfc, u32 val)
>> +{
>> + writel(val, nfc->base + INTR_STS_EN_OFST);
>> + writel(val, nfc->base + INTR_SIG_EN_OFST);
>> +}
>> +
>> +static int anfc_wait_for_event(struct anfc *nfc, u32 event)
>> +{
>> + struct completion *comp;
>> + int ret;
>> +
>> + if (event == XFER_COMPLETE)
>> + comp = &nfc->xfercomp;
>> + else
>> + comp = &nfc->bufrdy;
>> +
>> + ret = wait_for_completion_timeout(comp, msecs_to_jiffies(EVNT_TIMEOUT));
>> +
>> + return ret;
>> +}
>> +
>> +static inline void anfc_setpktszcnt(struct anfc *nfc, u32 pktsize,
>> + u32 pktcount)
>> +{
>> + writel(pktsize | (pktcount << PKT_CNT_SHIFT), nfc->base + PKT_OFST);
>> +}
>> +
>> +static inline void anfc_set_eccsparecmd(struct anfc *nfc, u8 cmd1, u8 cmd2)
>> +{
>> + writel(cmd1 | (cmd2 << CMD2_SHIFT) |
>> + (nfc->caddr_cycles << ADDR_CYCLES_SHIFT),
>> + nfc->base + ECC_SPR_CMD_OFST);
>> +}
>> +
>> +static void anfc_setpagecoladdr(struct anfc *nfc, u32 page, u16 col)
>> +{
>> + u32 val;
>> +
>> + writel(col | (page << PG_ADDR_SHIFT), nfc->base + MEM_ADDR1_OFST);
>> +
>> + val = readl(nfc->base + MEM_ADDR2_OFST);
>> + val = (val & ~MEM_ADDR_MASK) |
>> + ((page >> PG_ADDR_SHIFT) & MEM_ADDR_MASK);
>> + writel(val, nfc->base + MEM_ADDR2_OFST);
>> +}
>> +
>> +static void anfc_prepare_cmd(struct anfc *nfc, u8 cmd1, u8 cmd2,
>> + u8 dmamode, u32 pagesize, u8 addrcycles)
>> +{
>> + u32 regval;
>> +
>> + regval = cmd1 | (cmd2 << CMD2_SHIFT);
>> + if (dmamode && nfc->dma)
>> + regval |= DMA_ENABLE << DMA_EN_SHIFT;
>> + if (addrcycles)
>> + regval |= addrcycles << ADDR_CYCLES_SHIFT;
>> + if (pagesize)
>> + regval |= anfc_page(pagesize) << PAGE_SIZE_SHIFT;
>> + writel(regval, nfc->base + CMD_OFST);
>> +}
>> +
>> +static int anfc_device_ready(struct mtd_info *mtd,
>> + struct nand_chip *chip)
>> +{
>> + u8 status;
>> + u32 timeout = STATUS_TIMEOUT;
>> +
>> + while (timeout--) {
>> + chip->cmdfunc(mtd, NAND_CMD_STATUS, 0, 0);
>> + status = chip->read_byte(mtd);
>> + if (status & ONFI_STATUS_READY) {
>> + if (status & ONFI_STATUS_FAIL)
>> + return NAND_STATUS_FAIL;
>> + return 0;
>> + }
>> + }
>
> No, we can't just do a busy-wait loop at an arbitrary count of 2000
> cycles. Can you do something that's interrupt-based? Or at least time
> yourself with jiffies or something similar.

I will Jiffies as there is no interrupt status for this.

>
>> +
>> + pr_err("%s timed out\n", __func__);
>> + return -ETIMEDOUT;
>> +}
>> +
>> +static int anfc_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
>> + int page)
>> +{
>> + struct anfc *nfc = container_of(mtd, struct anfc, mtd);
>> +
>> + chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
>> + if (nfc->dma)
>> + nfc->rdintrmask = XFER_COMPLETE;
>> + else
>> + nfc->rdintrmask = READ_READY;
>> + chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
>> +
>> + return 0;
>> +}
>> +
>> +static int anfc_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
>> + int page)
>> +{
>> + struct anfc *nfc = container_of(mtd, struct anfc, mtd);
>> +
>> + nfc->iswriteoob = true;
>> + chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page);
>> + chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
>> + nfc->iswriteoob = false;
>> +
>> + return 0;
>> +}
>> +
>> +static void anfc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
>> +{
>> + u32 i, pktcount, buf_rd_cnt = 0, pktsize;
>> + u32 *bufptr = (u32 *)buf;
>> + struct anfc *nfc = container_of(mtd, struct anfc, mtd);
>> + dma_addr_t paddr = 0;
>> +
>> + if (nfc->curr_cmd == NAND_CMD_READ0) {
>> + pktsize = nfc->pktsize;
>> + if (mtd->writesize % pktsize)
>> + pktcount = mtd->writesize / pktsize + 1;
>> + else
>> + pktcount = mtd->writesize / pktsize;
>> + } else {
>> + pktsize = len;
>> + pktcount = 1;
>> + }
>> +
>> + anfc_setpktszcnt(nfc, pktsize, pktcount);
>> +
>> + if (nfc->dma) {
>> + paddr = dma_map_single(nfc->dev, buf, len, DMA_FROM_DEVICE);
>> + if (dma_mapping_error(nfc->dev, paddr)) {
>> + dev_err(nfc->dev, "Read buffer mapping error");
>> + return;
>> + }
>> + writel(paddr, nfc->base + DMA_ADDR0_OFST);
>> + writel(paddr >> 32, nfc->base + DMA_ADDR1_OFST);
>
> drivers/mtd/nand/arasan_nfc.c: In function âanfc_read_bufâ:
> drivers/mtd/nand/arasan_nfc.c:355:3: warning: right shift count >= width of type [enabled by default]
> writel(paddr >> 32, nfc->base + DMA_ADDR1_OFST);
> ^
>
> How about using upper_32_bits() and lower_32_bits()?

I just tried and it works. Thanks.

>
>> + anfc_enable_intrs(nfc, nfc->rdintrmask);
>> + writel(PROG_PGRD, nfc->base + PROG_OFST);
>> + anfc_wait_for_event(nfc, XFER_COMPLETE);
>> + dma_unmap_single(nfc->dev, paddr, len, DMA_FROM_DEVICE);
>> + return;
>> + }
>> +
>> + anfc_enable_intrs(nfc, nfc->rdintrmask);
>> + writel(PROG_PGRD, nfc->base + PROG_OFST);
>> +
>> + while (buf_rd_cnt < pktcount) {
>> +
>> + anfc_wait_for_event(nfc, READ_READY);
>> + buf_rd_cnt++;
>> +
>> + if (buf_rd_cnt == pktcount)
>> + anfc_enable_intrs(nfc, XFER_COMPLETE);
>> +
>> + for (i = 0; i < pktsize / 4; i++)
>> + bufptr[i] = readl(nfc->base + DATA_PORT_OFST);
>> +
>> + bufptr += (pktsize / 4);
>> +
>> + if (buf_rd_cnt < pktcount)
>> + anfc_enable_intrs(nfc, nfc->rdintrmask);
>> + }
>> +
>> + anfc_wait_for_event(nfc, XFER_COMPLETE);
>> +}
>> +
>> +static void anfc_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
>> +{
>> + u32 buf_wr_cnt = 0, pktcount = 1, i, pktsize;
>> + u32 *bufptr = (u32 *)buf;
>> + struct anfc *nfc = container_of(mtd, struct anfc, mtd);
>> + dma_addr_t paddr = 0;
>> +
>> + if (nfc->iswriteoob) {
>> + pktsize = len;
>> + pktcount = 1;
>> + } else {
>> + pktsize = nfc->pktsize;
>> + pktcount = mtd->writesize / pktsize;
>> + }
>> +
>> + anfc_setpktszcnt(nfc, pktsize, pktcount);
>> +
>> + if (nfc->dma) {
>> + paddr = dma_map_single(nfc->dev, (void *)buf, len,
>> + DMA_TO_DEVICE);
>> + if (dma_mapping_error(nfc->dev, paddr)) {
>> + dev_err(nfc->dev, "Write buffer mapping error");
>> + return;
>> + }
>> + writel(paddr, nfc->base + DMA_ADDR0_OFST);
>> + writel(paddr >> 32, nfc->base + DMA_ADDR1_OFST);
>
> Same problem as in read_buf().
>
>> + anfc_enable_intrs(nfc, XFER_COMPLETE);
>> + writel(PROG_PGPROG, nfc->base + PROG_OFST);
>> + anfc_wait_for_event(nfc, XFER_COMPLETE);
>> + dma_unmap_single(nfc->dev, paddr, len, DMA_TO_DEVICE);
>> + return;
>> + }
>> +
>> + anfc_enable_intrs(nfc, WRITE_READY);
>> + writel(PROG_PGPROG, nfc->base + PROG_OFST);
>> +
>> + while (buf_wr_cnt < pktcount) {
>> + anfc_wait_for_event(nfc, WRITE_READY);
>> +
>> + buf_wr_cnt++;
>> + if (buf_wr_cnt == pktcount)
>> + anfc_enable_intrs(nfc, XFER_COMPLETE);
>> +
>> + for (i = 0; i < (pktsize / 4); i++)
>> + writel(bufptr[i], nfc->base + DATA_PORT_OFST);
>> +
>> + bufptr += (pktsize / 4);
>> +
>> + if (buf_wr_cnt < pktcount)
>> + anfc_enable_intrs(nfc, WRITE_READY);
>> + }
>> +
>> + anfc_wait_for_event(nfc, XFER_COMPLETE);
>> +}
>> +
>> +static int anfc_read_page_hwecc(struct mtd_info *mtd,
>> + struct nand_chip *chip, uint8_t *buf,
>> + int oob_required, int page)
>> +{
>> + u32 val;
>> + struct anfc *nfc = container_of(mtd, struct anfc, mtd);
>> +
>> + anfc_set_eccsparecmd(nfc, NAND_CMD_RNDOUT, NAND_CMD_RNDOUTSTART);
>> +
>> + val = readl(nfc->base + CMD_OFST);
>> + val = val | ECC_ENABLE;
>> + writel(val, nfc->base + CMD_OFST);
>> +
>> + if (nfc->dma)
>> + nfc->rdintrmask = XFER_COMPLETE;
>> + else
>> + nfc->rdintrmask = READ_READY;
>> +
>> + if (!nfc->bch)
>> + nfc->rdintrmask = MBIT_ERROR;
>> +
>> + chip->read_buf(mtd, buf, mtd->writesize);
>> +
>> + val = readl(nfc->base + ECC_ERR_CNT_OFST);
>> + if (nfc->bch) {
>> + mtd->ecc_stats.corrected += val & PAGE_ERR_CNT_MASK;
>> + } else {
>> + val = readl(nfc->base + ECC_ERR_CNT_1BIT_OFST);
>> + mtd->ecc_stats.corrected += val;
>> + val = readl(nfc->base + ECC_ERR_CNT_2BIT_OFST);
>> + mtd->ecc_stats.failed += val;
>> + /* Clear ecc error count register 1Bit, 2Bit */
>> + writel(0x0, nfc->base + ECC_ERR_CNT_1BIT_OFST);
>> + writel(0x0, nfc->base + ECC_ERR_CNT_2BIT_OFST);
>> + }
>> + nfc->err = false;
>> +
>> + if (oob_required)
>> + chip->ecc.read_oob(mtd, chip, page);
>> +
>> + return 0;
>> +}
>> +
>> +static int anfc_write_page_hwecc(struct mtd_info *mtd,
>> + struct nand_chip *chip, const uint8_t *buf,
>> + int oob_required)
>> +{
>> + u32 val, i;
>> + struct anfc *nfc = container_of(mtd, struct anfc, mtd);
>> + uint8_t *ecc_calc = chip->buffers->ecccalc;
>> + uint32_t *eccpos = chip->ecc.layout->eccpos;
>> +
>> + anfc_set_eccsparecmd(nfc, NAND_CMD_RNDIN, 0);
>> +
>> + val = readl(nfc->base + CMD_OFST);
>> + val = val | ECC_ENABLE;
>> + writel(val, nfc->base + CMD_OFST);
>> +
>> + chip->write_buf(mtd, buf, mtd->writesize);
>> +
>> + if (oob_required) {
>> + anfc_device_ready(mtd, chip);
>> + chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, nfc->page);
>> + if (nfc->dma)
>> + nfc->rdintrmask = XFER_COMPLETE;
>> + else
>> + nfc->rdintrmask = READ_READY;
>> + chip->read_buf(mtd, ecc_calc, mtd->oobsize);
>> + for (i = 0; i < chip->ecc.total; i++)
>> + chip->oob_poi[eccpos[i]] = ecc_calc[eccpos[i]];
>> + chip->ecc.write_oob(mtd, chip, nfc->page);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static u8 anfc_read_byte(struct mtd_info *mtd)
>> +{
>> + struct anfc *nfc = container_of(mtd, struct anfc, mtd);
>> +
>> + return nfc->buf[nfc->bufshift++];
>> +}
>> +
>> +static void anfc_readfifo(struct anfc *nfc, u32 prog, u32 size)
>> +{
>> + u32 i, *bufptr = (u32 *)&nfc->buf[0];
>> +
>> + anfc_enable_intrs(nfc, READ_READY);
>> +
>> + writel(prog, nfc->base + PROG_OFST);
>> + anfc_wait_for_event(nfc, READ_READY);
>> +
>> + anfc_enable_intrs(nfc, XFER_COMPLETE);
>> +
>> + for (i = 0; i < size / 4; i++)
>> + bufptr[i] = readl(nfc->base + DATA_PORT_OFST);
>> +
>> + anfc_wait_for_event(nfc, XFER_COMPLETE);
>> +}
>> +
>> +static int anfc_ecc_init(struct mtd_info *mtd,
>> + struct nand_ecc_ctrl *ecc)
>> +{
>> + u32 oob_index, i, ecc_addr, regval, bchmode = 0;
>> + struct nand_chip *nand_chip = mtd->priv;
>> + struct anfc *nfc = container_of(mtd, struct anfc, mtd);
>> + int found = -1;
>> +
>> + nand_chip->ecc.mode = NAND_ECC_HW;
>> + nand_chip->ecc.read_page = anfc_read_page_hwecc;
>> + nand_chip->ecc.write_page = anfc_write_page_hwecc;
>> + nand_chip->ecc.write_oob = anfc_write_oob;
>> + nand_chip->ecc.read_oob = anfc_read_oob;
>> +
>> + for (i = 0; i < sizeof(ecc_matrix) / sizeof(struct anfc_ecc_matrix);
>> + i++) {
>> + if ((ecc_matrix[i].pagesize == mtd->writesize) &&
>> + (ecc_matrix[i].codeword_size >= nand_chip->ecc_step_ds)) {
>> + if (ecc_matrix[i].eccbits >=
>> + nand_chip->ecc_strength_ds) {
>> + found = i;
>> + break;
>> + }
>> + found = i;
>> + }
>> + }
>> +
>> + if (found < 0) {
>> + dev_err(nfc->dev, "ECC scheme not supported");
>> + return 1;
>> + }
>> + if (ecc_matrix[found].bch) {
>> + switch (ecc_matrix[found].eccbits) {
>> + case 12:
>> + bchmode = 0x1;
>> + break;
>> + case 8:
>> + bchmode = 0x2;
>> + break;
>> + case 4:
>> + bchmode = 0x3;
>> + break;
>> + case 24:
>> + bchmode = 0x4;
>> + break;
>> + default:
>> + bchmode = 0x0;
>> + }
>> + }
>> +
>> + nand_chip->ecc.strength = ecc_matrix[found].eccbits;
>> + nand_chip->ecc.size = ecc_matrix[found].codeword_size;
>> + nand_chip->ecc.steps = ecc_matrix[found].pagesize /
>> + ecc_matrix[found].codeword_size;
>> + nand_chip->ecc.bytes = ecc_matrix[found].eccsize /
>> + nand_chip->ecc.steps;
>> + nfc->ecclayout.eccbytes = ecc_matrix[found].eccsize;
>> + nfc->bch = ecc_matrix[found].bch;
>> + oob_index = nand_chip->onfi_params.spare_bytes_per_page -
>> + nfc->ecclayout.eccbytes;
>
> sparse doesn't like this:
>
> drivers/mtd/nand/arasan_nfc.c:599:43: warning: restricted __le16 degrades to integer [sparse]
>
> You need to use __le16_to_cpu() when accessing ONFI params. But really,
> you should be using mtd->oobsize, not onfi_params

Correct. I can use mtd->oobsize.

>
>> + ecc_addr = mtd->writesize + oob_index;
>> +
>> + for (i = 0; i < nand_chip->ecc.size; i++)
>> + nfc->ecclayout.eccpos[i] = oob_index + i;
>> +
>> + nfc->ecclayout.oobfree->offset = 2;
>> + nfc->ecclayout.oobfree->length = oob_index -
>> + nfc->ecclayout.oobfree->offset;
>> +
>> + nand_chip->ecc.layout = &(nfc->ecclayout);
>> + regval = ecc_addr | (ecc_matrix[found].eccsize << ECC_SIZE_SHIFT) |
>> + (ecc_matrix[found].bch << BCH_EN_SHIFT);
>> + writel(regval, nfc->base + ECC_OFST);
>> +
>> + regval = readl(nfc->base + MEM_ADDR2_OFST);
>> + regval = (regval & ~(BCH_MODE_MASK)) | (bchmode << BCH_MODE_SHIFT);
>> + writel(regval, nfc->base + MEM_ADDR2_OFST);
>> +
>> + if (nand_chip->ecc_step_ds >= 1024)
>> + nfc->pktsize = 1024;
>> + else
>> + nfc->pktsize = 512;
>> +
>> + return 0;
>> +}
>> +
>> +static void anfc_cmd_function(struct mtd_info *mtd,
>> + unsigned int cmd, int column, int page_addr)
>> +{
>> + struct anfc *nfc = container_of(mtd, struct anfc, mtd);
>> + bool wait = false, read = false;
>> + u32 addrcycles, prog;
>> + u32 *bufptr = (u32 *)&nfc->buf[0];
>> +
>> + nfc->bufshift = 0;
>> + nfc->curr_cmd = cmd;
>> +
>> + if (page_addr == -1)
>> + page_addr = 0;
>> + if (column == -1)
>> + column = 0;
>> +
>> + switch (cmd) {
>> + case NAND_CMD_RESET:
>> + anfc_prepare_cmd(nfc, cmd, 0, 0, 0, 0);
>> + prog = PROG_RST;
>> + wait = true;
>> + break;
>> + case NAND_CMD_SEQIN:
>> + addrcycles = nfc->raddr_cycles + nfc->caddr_cycles;
>> + nfc->page = page_addr;
>> + anfc_prepare_cmd(nfc, cmd, NAND_CMD_PAGEPROG, 1,
>> + mtd->writesize, addrcycles);
>> + anfc_setpagecoladdr(nfc, page_addr, column);
>> + break;
>> + case NAND_CMD_READOOB:
>> + column += mtd->writesize;
>> + case NAND_CMD_READ0:
>> + case NAND_CMD_READ1:
>> + addrcycles = nfc->raddr_cycles + nfc->caddr_cycles;
>> + anfc_prepare_cmd(nfc, NAND_CMD_READ0, NAND_CMD_READSTART, 1,
>> + mtd->writesize, addrcycles);
>> + anfc_setpagecoladdr(nfc, page_addr, column);
>> + break;
>> + case NAND_CMD_RNDOUT:
>> + anfc_prepare_cmd(nfc, cmd, NAND_CMD_RNDOUTSTART, 1,
>> + mtd->writesize, 2);
>> + anfc_setpagecoladdr(nfc, page_addr, column);
>> + if (nfc->dma)
>> + nfc->rdintrmask = XFER_COMPLETE;
>> + else
>> + nfc->rdintrmask = READ_READY;
>> + break;
>> + case NAND_CMD_PARAM:
>> + anfc_prepare_cmd(nfc, cmd, 0, 0, 0, 1);
>> + anfc_setpagecoladdr(nfc, page_addr, column);
>> + anfc_setpktszcnt(nfc, sizeof(struct nand_onfi_params), 1);
>> + anfc_readfifo(nfc, PROG_RDPARAM,
>> + sizeof(struct nand_onfi_params));
>> + break;
>> + case NAND_CMD_READID:
>> + anfc_prepare_cmd(nfc, cmd, 0, 0, 0, 1);
>> + anfc_setpagecoladdr(nfc, page_addr, column);
>> + anfc_setpktszcnt(nfc, ONFI_ID_LEN, 1);
>> + anfc_readfifo(nfc, PROG_RDID, ONFI_ID_LEN);
>> + break;
>> + case NAND_CMD_ERASE1:
>> + addrcycles = nfc->raddr_cycles;
>> + prog = PROG_ERASE;
>> + anfc_prepare_cmd(nfc, cmd, NAND_CMD_ERASE2, 0, 0, addrcycles);
>> + column = page_addr & 0xffff;
>> + page_addr = (page_addr >> PG_ADDR_SHIFT) & 0xffff;
>> + anfc_setpagecoladdr(nfc, page_addr, column);
>> + wait = true;
>> + break;
>> + case NAND_CMD_STATUS:
>> + anfc_prepare_cmd(nfc, cmd, 0, 0, 0, 0);
>> + anfc_setpktszcnt(nfc, 1, 1);
>> + anfc_setpagecoladdr(nfc, page_addr, column);
>> + prog = PROG_STATUS;
>> + wait = read = true;
>> + break;
>> + default:
>> + return;
>> + }
>> +
>> + if (wait) {
>> + anfc_enable_intrs(nfc, XFER_COMPLETE);
>> + writel(prog, nfc->base + PROG_OFST);
>> + anfc_wait_for_event(nfc, XFER_COMPLETE);
>> + }
>> +
>> + if (read)
>> + bufptr[0] = readl(nfc->base + FLASH_STS_OFST);
>> +}
>> +
>> +static void anfc_select_chip(struct mtd_info *mtd, int num)
>> +{
>> + u32 val;
>> + struct anfc *nfc = container_of(mtd, struct anfc, mtd);
>> +
>> + if (num == -1)
>> + return;
>> +
>> + val = readl(nfc->base + MEM_ADDR2_OFST);
>> + val = (val & ~(CS_MASK)) | (num << CS_SHIFT);
>> + writel(val, nfc->base + MEM_ADDR2_OFST);
>> +}
>> +
>> +static irqreturn_t anfc_irq_handler(int irq, void *ptr)
>> +{
>> + struct anfc *nfc = ptr;
>> + u32 regval = 0, status;
>> +
>> + status = readl(nfc->base + INTR_STS_OFST);
>> + if (status & XFER_COMPLETE) {
>> + complete(&nfc->xfercomp);
>> + regval |= XFER_COMPLETE;
>> + }
>> +
>> + if (status & READ_READY) {
>> + complete(&nfc->bufrdy);
>> + regval |= READ_READY;
>> + }
>> +
>> + if (status & WRITE_READY) {
>> + complete(&nfc->bufrdy);
>> + regval |= WRITE_READY;
>> + }
>> +
>> + if (status & MBIT_ERROR) {
>> + nfc->err = true;
>> + complete(&nfc->bufrdy);
>> + regval |= MBIT_ERROR;
>> + }
>> +
>> + if (regval) {
>> + writel(regval, nfc->base + INTR_STS_OFST);
>> + writel(0, nfc->base + INTR_STS_EN_OFST);
>> + writel(0, nfc->base + INTR_SIG_EN_OFST);
>> +
>> + return IRQ_HANDLED;
>> + }
>> +
>> + return IRQ_NONE;
>> +}
>> +
>> +static int anfc_probe(struct platform_device *pdev)
>> +{
>> + struct anfc *nfc;
>> + struct mtd_info *mtd;
>> + struct nand_chip *nand_chip;
>> + struct resource *res;
>> + struct mtd_part_parser_data ppdata;
>> + int err;
>> +
>> + nfc = devm_kzalloc(&pdev->dev, sizeof(*nfc), GFP_KERNEL);
>> + if (!nfc)
>> + return -ENOMEM;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + nfc->base = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(nfc->base))
>> + return PTR_ERR(nfc->base);
>> +
>> + mtd = &nfc->mtd;
>> + nand_chip = &nfc->chip;
>> + nand_chip->priv = nfc;
>> + mtd->priv = nand_chip;
>> + mtd->owner = THIS_MODULE;
>> + mtd->name = DRIVER_NAME;
>> + nfc->dev = &pdev->dev;
>
> You should set mtd->dev.parent too.


Ok.

>
>> +
>> + nand_chip->cmdfunc = anfc_cmd_function;
>> + nand_chip->waitfunc = anfc_device_ready;
>> + nand_chip->chip_delay = 30;
>> + nand_chip->read_buf = anfc_read_buf;
>> + nand_chip->write_buf = anfc_write_buf;
>> + nand_chip->read_byte = anfc_read_byte;
>> + nand_chip->bbt_options = NAND_BBT_USE_FLASH;
>> + nand_chip->select_chip = anfc_select_chip;
>> + mtd->size = nand_chip->chipsize;
>
> This line looks superfluous. chipsize isn't even set at this point.

I will remove this.

>
>> + nfc->dma = of_property_read_bool(pdev->dev.of_node,
>> + "arasan,has-mdma");
>> + platform_set_drvdata(pdev, nfc);
>> + init_completion(&nfc->bufrdy);
>> + init_completion(&nfc->xfercomp);
>> + nfc->irq = platform_get_irq(pdev, 0);
>
> Check for errors?

I thought devm_request_irq will return error if an invalid irq number is passed.
i will cross check once again and add error check if required.

>
>> + err = devm_request_irq(&pdev->dev, nfc->irq, anfc_irq_handler,
>> + 0, "arasannfc", nfc);
>> + if (err)
>> + return err;
>> +
>> + if (nand_scan_ident(mtd, 1, NULL)) {
>> + dev_err(&pdev->dev, "nand_scan_ident for NAND failed\n");
>> + return -ENXIO;
>> + }
>> + nfc->raddr_cycles = nand_chip->onfi_params.addr_cycles & 0xF;
>> + nfc->caddr_cycles = (nand_chip->onfi_params.addr_cycles >> 4) & 0xF;
>
> Do you *have* to get this from ONFI? What if someone uses non-ONFI
> flash? You should at least check if this is an ONFI flash before using
> these param values.

Yes, i have to get this from onfi because though most of the flash
devices typically
using 5 address cycles (row + col) we have seen few spansion devices expecting
4 address cycles.

probably

if (nand_chip->onfi_version) // or add an equivalent API in mtd/nand.h
get the address cycles info from onfi
else
use default 5 address cycles.


Please let me know is it the correct implementation.

>
>> +
>> + if (anfc_ecc_init(mtd, &nand_chip->ecc))
>> + return -ENXIO;
>> +
>> + if (nand_scan_tail(mtd)) {
>> + dev_err(&pdev->dev, "nand_scan_tail for NAND failed\n");
>> + return -ENXIO;
>> + }
>> +
>> + ppdata.of_node = pdev->dev.of_node;
>> +
>> + mtd_device_parse_register(&nfc->mtd, NULL, &ppdata, NULL, 0);
>> + return 0;
>
> You're ignoring the return value from mtd_device_parse_register(). How
> about:

Ok.

Thanks Brian for the review.

Regards,
Punnaiah
>
> return mtd_device_parse_register(&nfc->mtd, NULL, &ppdata, NULL, 0);
>
>> +}
>> +
>> +static int anfc_remove(struct platform_device *pdev)
>> +{
>> + struct anfc *nfc = platform_get_drvdata(pdev);
>> +
>> + nand_release(&nfc->mtd);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id anfc_ids[] = {
>> + { .compatible = "arasan,nfc-v3p10" },
>> + { }
>> +};
>> +MODULE_DEVICE_TABLE(of, anfc_ids);
>> +
>> +static struct platform_driver anfc_driver = {
>> + .driver = {
>> + .name = DRIVER_NAME,
>> + .of_match_table = anfc_ids,
>> + },
>> + .probe = anfc_probe,
>> + .remove = anfc_remove,
>> +};
>> +module_platform_driver(anfc_driver);
>> +
>> +MODULE_LICENSE("GPL");
>> +MODULE_AUTHOR("Xilinx, Inc");
>> +MODULE_DESCRIPTION("Arasan NAND Flash Controller Driver");
>
> Brian
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