RE: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface

From: Naga Sureshkumar Relli
Date: Tue Jul 31 2018 - 03:52:53 EST

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In reply to: Miquel Raynal: "Re: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface"
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Hi Miquel,

Thanks for the review.

> -----Original Message-----
> From: Miquel Raynal [mailto:miquel.raynal@xxxxxxxxxxx]
> Sent: Monday, July 30, 2018 12:46 AM
> To: Naga Sureshkumar Relli <nagasure@xxxxxxxxxx>
> Cc: boris.brezillon@xxxxxxxxxxx; richard@xxxxxx; dwmw2@xxxxxxxxxxxxx;
> computersforpeace@xxxxxxxxx; marek.vasut@xxxxxxxxx; f.fainelli@xxxxxxxxx;
> mmayer@xxxxxxxxxxxx; rogerq@xxxxxx; ladis@xxxxxxxxxxxxxx; ada@xxxxxxxxxx;
> honghui.zhang@xxxxxxxxxxxx; linus.walleij@xxxxxxxxxx; linux-mtd@xxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; nagasureshkumarrelli@xxxxxxxxx; Michal Simek
> <michals@xxxxxxxxxx>
> Subject: Re: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353
> smc nand interface
>
> Hi Naga,
>
> Naga Sureshkumar Relli <naga.sureshkumar.relli@xxxxxxxxxx> wrote on Wed, 11 Jul 2018
> 13:06:52 +0530:
>
> > Add driver for arm pl353 static memory controller nand interface with
> > HW ECC support. This controller is used in Xilinx Zynq SoC for
> > interfacing the NAND flash memory.
> >
> > Signed-off-by: Naga Sureshkumar Relli
> > <naga.sureshkumar.relli@xxxxxxxxxx>
> > ---
> > Changes in v11:
> > - Removed Documentation patch and added the required info in driver as
> > per Boris comments.
> > - Removed unwanted variables from pl353_nand_info as per Miquel
> > comments
> > - Removed IO_ADDR_R/W.
> > - Replaced onhot() with hweight32()
> > - Defined macros for static values in function
> > pl353_nand_correct_data()
> > - Removed all unnecessary delays
> > - Used nand_wait_ready() where ever is required
> > - Modifed the pl353_setup_data_interface() logic as per Miquel comments.
> > - Taken array instead of 7 values in pl353_setup_data_interface() and pass
> > it to smc driver.
> > - Added check to collect the return value of mtd_device_register().
> > Changes in 10:
> > - Typos correction like nand to NAND and soc to SOC etc..
> > - Defined macros for the values in pl353_nand_calculate_hwecc()
> > - Modifed ecc_status from int to char in pl353_nand_calculate_hwecc()
> > - Changed the return type form int to bool to the function
> > onehot()
> > - Removed udelay(1000) in pl353_cmd_function, as it is not required
> > - Dropped ecc->hwctl = NULL in pl353_ecc_init()
> > - Added an error message in pl353_ecc_init(), when there is no matching
> > oobsize
> > - Changed the variable from xnand to xnfc
> > - Added logic to get mtd->name from DT, if it is specified in DT
> > Changes in v9:
> > - Addressed the below comments given by Miquel
> > - instead of using pl353_nand_write32, use directly writel_relaxed
> > - Fixed check patch warnings
> > - Renamed write_buf/read_buf to write_data_op/read_data_op
> > - use BIT macro instead of 1 << nr
> > - Use NAND_ROW_ADDR_3 flag
> > - Use nand_wait_ready()
> > - Removed swecc functions
> > - Use address cycles as per size, instead of reading it from
> > Parameter page
> > - Instead of writing too many patterns, use optional property Changes
> > in v8:
> > - Added exec_op() implementation
> > - Fixed the below v7 review comments
> > - removed mtd_info from pl353_nand_info struct
> > - Corrected ecc layout offsets
> > - Added on-die ecc support
> > Changes in v7:
> > - Currently not implemented the memclk rate adjustments. I will
> > look into this later and once the basic driver is accepted.
> > - Fixed GPL licence ident
> > Changes in v6:
> > - Fixed the checkpatch.pl reported warnings
> > - Using the address cycles information from the onfi param page
> > earlier it is hardcoded to 5 in driver Changes in v5:
> > - Configure the nand timing parameters as per the onfi spec Changes in v4:
> > - Updated the driver to sync with pl353_smc driver APIs Changes in
> > v3:
> > - implemented the proper error codes
> > - further breakdown this patch to multiple sets
> > - added the controller and driver details to Documentation section
> > - updated the licenece to GPLv2
> > - reorganized the pl353_nand_ecc_init function Changes in v2:
> > - use "depends on" rather than "select" option in kconfig
> > - remove unused variable parts
> > ---
> > drivers/mtd/nand/raw/Kconfig | 7 +
> > drivers/mtd/nand/raw/Makefile | 1 +
> > drivers/mtd/nand/raw/pl353_nand.c | 1314
> > +++++++++++++++++++++++++++++++++++++
> > 3 files changed, 1322 insertions(+)
> > create mode 100644 drivers/mtd/nand/raw/pl353_nand.c
> >
> > diff --git a/drivers/mtd/nand/raw/Kconfig
> > b/drivers/mtd/nand/raw/Kconfig index 6871ff0..1c5d528 100644
> > --- a/drivers/mtd/nand/raw/Kconfig
> > +++ b/drivers/mtd/nand/raw/Kconfig
> > @@ -530,4 +530,11 @@ config MTD_NAND_MTK
> > Enables support for NAND controller on MTK SoCs.
> > This controller is found on mt27xx, mt81xx, mt65xx SoCs.
> >
> > +config MTD_NAND_PL353
> > + tristate "ARM Pl353 NAND flash driver"
> > + depends on MTD_NAND && ARM
> > + depends on PL353_SMC
> > + help
> > + Enables support for PrimeCell Static Memory Controller PL353.
> > +
> > endif # MTD_NAND
> > diff --git a/drivers/mtd/nand/raw/Makefile
> > b/drivers/mtd/nand/raw/Makefile index 165b7ef..1c702e1 100644
> > --- a/drivers/mtd/nand/raw/Makefile
> > +++ b/drivers/mtd/nand/raw/Makefile
> > @@ -56,6 +56,7 @@ obj-$(CONFIG_MTD_NAND_HISI504) +=
> hisi504_nand.o
> > obj-$(CONFIG_MTD_NAND_BRCMNAND) += brcmnand/
> > obj-$(CONFIG_MTD_NAND_QCOM) += qcom_nandc.o
> > obj-$(CONFIG_MTD_NAND_MTK) += mtk_ecc.o mtk_nand.o
> > +obj-$(CONFIG_MTD_NAND_PL353) += pl353_nand.o
> >
> > nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o
> > nand-objs += nand_amd.o diff --git a/drivers/mtd/nand/raw/pl353_nand.c
> > b/drivers/mtd/nand/raw/pl353_nand.c
> > new file mode 100644
> > index 0000000..3fa9ba07
> > --- /dev/null
> > +++ b/drivers/mtd/nand/raw/pl353_nand.c
> > @@ -0,0 +1,1314 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * ARM PL353 NAND flash controller driver
> > + *
> > + * Copyright (C) 2017 Xilinx, Inc
> > + * Author: Punnaiah chowdary kalluri <punnaiah@xxxxxxxxxx>
> > + * Author: Naga Sureshkumar Relli <nagasure@xxxxxxxxxx>
> > + *
> > + */
> > +
> > +#include <linux/err.h>
> > +#include <linux/delay.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/ioport.h>
> > +#include <linux/irq.h>
> > +#include <linux/module.h>
> > +#include <linux/moduleparam.h>
> > +#include <linux/mtd/mtd.h>
> > +#include <linux/mtd/rawnand.h>
> > +#include <linux/mtd/nand_ecc.h>
> > +#include <linux/mtd/partitions.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_device.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +#include <linux/pl353-smc.h>
> > +#include <linux/clk.h>
> > +
> > +#define PL353_NAND_DRIVER_NAME "pl353-nand"
> > +
> > +/* NAND flash driver defines */
> > +#define PL353_NAND_CMD_PHASE 1 /* End command valid in command
> phase */
> > +#define PL353_NAND_DATA_PHASE 2 /* End command valid in data phase
> */
> > +#define PL353_NAND_ECC_SIZE 512 /* Size of data for ECC operation */
> > +
> > +/* Flash memory controller operating parameters */
> > +
> > +#define PL353_NAND_ECC_CONFIG (BIT(4) | /* ECC read at end of page */
> \
> > + (0 << 5)) /* No Jumping */
> > +
> > +/* AXI Address definitions */
> > +#define START_CMD_SHIFT 3
> > +#define END_CMD_SHIFT 11
> > +#define END_CMD_VALID_SHIFT 20
> > +#define ADDR_CYCLES_SHIFT 21
> > +#define CLEAR_CS_SHIFT 21
> > +#define ECC_LAST_SHIFT 10
> > +#define COMMAND_PHASE (0 << 19)
> > +#define DATA_PHASE BIT(19)
> > +
> > +#define PL353_NAND_ECC_LAST BIT(ECC_LAST_SHIFT) /* Set
> ECC_Last */
> > +#define PL353_NAND_CLEAR_CS BIT(CLEAR_CS_SHIFT) /* Clear chip
> select */
> > +
> > +#define ONDIE_ECC_FEATURE_ADDR 0x90
> > +#define PL353_NAND_ECC_BUSY_TIMEOUT (1 * HZ)
> > +#define PL353_NAND_DEV_BUSY_TIMEOUT (1 * HZ)
> > +#define PL353_NAND_LAST_TRANSFER_LENGTH 4
> > +#define PL353_NAND_ECC_VALID_SHIFT 24
> > +#define PL353_NAND_ECC_VALID_MASK 0x40
> > +#define PL353_ECC_BITS_BYTEOFF_MASK 0x1FF
> > +#define PL353_ECC_BITS_BITOFF_MASK 0x7
> > +#define PL353_ECC_BIT_MASK 0xFFF
> > +#define PL353_TREA_MAX_VALUE 1
> > +
> > +struct pl353_nfc_op {
> > + u32 cmnds[4];
> > + u32 thirdrow;
> > + u32 type;
> > + u32 end_cmd;
> > + u32 addrs;
> > + u32 len;
> > + u32 naddrs;
> > + u32 addr5;
> > + u32 addr6;
> > + unsigned int data_instr_idx;
> > + unsigned int rdy_timeout_ms;
> > + unsigned int rdy_delay_ns;
> > + unsigned int cle_ale_delay_ns;
> > + const struct nand_op_instr *data_instr; };
> > +
> > +/**
> > + * struct pl353_nand_info - Defines the NAND flash driver instance
>
> I suppose you mean "NAND flash controller driver instance", in this case, pl353_nand_info
> could be pl353_nand_controller?
Yes, I will change pl353_nand_info to pl353_nand_controller.

>
> > + * @chip: NAND chip information structure
> > + * @dev: Parent device (used to print error messages)
> > + * @nand_base: Virtual address of the NAND flash device
> > + * @nandaddr: Virtual address of the NAND flash device for
> > + * data read/writes
> > + * @addr_cycles: Address cycles
> > + * @mclk: Memory controller clock
> > + */
> > +struct pl353_nand_info {
> > + struct nand_chip chip;
> > + struct device *dev;
> > + void __iomem *nand_base;
> > + void __iomem *nandaddr;
>
> Maybe nand_base and nandaddr are not very descriptive names. What about 'regs' intead of
> nand_base? And if nandaddr is a buffer address, what about "buf_addr"?
Miquel, the nand_base is actual io remapped address, and nandaddr is the address that can be used
During data transfers(i.e command phase and data phase)
It can be found in "Table 2-2 NAND AXI address setup" of
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0380g/DDI0380G_smc_pl350_series_r2p1_trm.pdf
and yes, I will change the naming's as mentioned above.

>
> > + u8 addr_cycles;
> > + struct clk *mclk;
> > +};
> > +
> > +static int pl353_ecc_ooblayout16_ecc(struct mtd_info *mtd, int section,
> > + struct mtd_oob_region *oobregion) {
> > + struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > + if (section >= chip->ecc.steps)
> > + return -ERANGE;
> > +
> > + oobregion->offset = (section * chip->ecc.bytes);
> > + oobregion->length = chip->ecc.bytes;
> > +
> > + return 0;
> > +}
> > +
> > +static int pl353_ecc_ooblayout16_free(struct mtd_info *mtd, int section,
> > + struct mtd_oob_region *oobregion) {
> > + struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > + if (section >= chip->ecc.steps)
> > + return -ERANGE;
> > +
> > + oobregion->offset = (section * chip->ecc.bytes) + 8;
> > + oobregion->length = 8;
> > +
> > + return 0;
> > +}
> > +
> > +static const struct mtd_ooblayout_ops pl353_ecc_ooblayout16_ops = {
> > + .ecc = pl353_ecc_ooblayout16_ecc,
> > + .free = pl353_ecc_ooblayout16_free,
> > +};
> > +
> > +static int pl353_ecc_ooblayout64_ecc(struct mtd_info *mtd, int section,
> > + struct mtd_oob_region *oobregion) {
> > + struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > + if (section >= chip->ecc.steps)
> > + return -ERANGE;
> > +
> > + oobregion->offset = (section * chip->ecc.bytes) + 52;
> > + oobregion->length = chip->ecc.bytes;
> > +
> > + return 0;
> > +}
> > +
> > +static int pl353_ecc_ooblayout64_free(struct mtd_info *mtd, int section,
> > + struct mtd_oob_region *oobregion) {
> > + struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > + if (section)
> > + return -ERANGE;
> > +
> > + if (section >= chip->ecc.steps)
> > + return -ERANGE;
> > +
> > + oobregion->offset = (section * chip->ecc.bytes) + 2;
> > + oobregion->length = 50;
> > +
> > + return 0;
> > +}
> > +
> > +static const struct mtd_ooblayout_ops pl353_ecc_ooblayout64_ops = {
> > + .ecc = pl353_ecc_ooblayout64_ecc,
> > + .free = pl353_ecc_ooblayout64_free,
> > +};
> > +
> > +/* Generic flash bbt decriptors */
> > +static u8 bbt_pattern[] = { 'B', 'b', 't', '0' }; static u8
> > +mirror_pattern[] = { '1', 't', 'b', 'B' };
> > +
> > +static struct nand_bbt_descr bbt_main_descr = {
> > + .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE |
> NAND_BBT_WRITE
> > + | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
> > + .offs = 4,
> > + .len = 4,
> > + .veroffs = 20,
> > + .maxblocks = 4,
> > + .pattern = bbt_pattern
> > +};
> > +
> > +static struct nand_bbt_descr bbt_mirror_descr = {
> > + .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE |
> NAND_BBT_WRITE
> > + | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
> > + .offs = 4,
> > + .len = 4,
> > + .veroffs = 20,
> > + .maxblocks = 4,
> > + .pattern = mirror_pattern
> > +};
> > +
> > +/**
> > + * pl353_nand_read_data_op - read chip data into buffer
> > + * @chip: Pointer to the NAND chip info structure
> > + * @in: Pointer to the buffer to store read data
> > + * @len: Number of bytes to read
> > + * Return: Always return zero
> > + */
> > +static int pl353_nand_read_data_op(struct nand_chip *chip,
> > + u8 *in,
> > + unsigned int len)
> > +{
> > + int i;
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > +
> > + if (IS_ALIGNED((uint32_t)in, sizeof(uint32_t)) &&
> > + IS_ALIGNED(len, sizeof(uint32_t))) {
> > + u32 *ptr = (u32 *)in;
> > +
> > + len /= 4;
> > + for (i = 0; i < len; i++)
> > + ptr[i] = readl(xnfc->nandaddr);
> > + } else {
> > + for (i = 0; i < len; i++)
> > + in[i] = readb(xnfc->nandaddr);
> > + }
>
> What about reading 0-3 bytes with readb if the driver is not aligned, then doing aligned
> access with readl until readb must be used again for the last 0-3 bytes?
The else case is handling that right?

>
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_write_buf - write buffer to chip
> > + * @mtd: Pointer to the mtd info structure
> > + * @buf: Pointer to the buffer to store write data
> > + * @len: Number of bytes to write
> > + */
> > +static void pl353_nand_write_data_op(struct mtd_info *mtd, const u8 *buf,
> > + int len)
> > +{
> > + int i;
> > + struct nand_chip *chip = mtd_to_nand(mtd);
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > +
> > + if (IS_ALIGNED((uint32_t)buf, sizeof(uint32_t)) &&
> > + IS_ALIGNED(len, sizeof(uint32_t))) {
> > + u32 *ptr = (u32 *)buf;
> > +
> > + len /= 4;
> > + for (i = 0; i < len; i++)
> > + writel(ptr[i], xnfc->nandaddr);
> > + } else {
> > + for (i = 0; i < len; i++)
> > + writeb(buf[i], xnfc->nandaddr);
> > + }
>
> Ditto.
>
> > +}
> > +
> > +/**
> > + * pl353_nand_calculate_hwecc - Calculate Hardware ECC
> > + * @mtd: Pointer to the mtd_info structure
> > + * @data: Pointer to the page data
> > + * @ecc: Pointer to the ECC buffer where ECC data needs to be stored
> > + *
> > + * This function retrieves the Hardware ECC data from the controller
> > +and returns
> > + * ECC data back to the MTD subsystem.
> > + * It operates on a number of 512 byte blocks of NAND memory and can
> > +be
> > + * programmed to store the ECC codes after the data in memory. For
> > +writes,
> > + * the ECC is written to the spare area of the page. For reads, the
> > +result of
> > + * a block ECC check are made available to the device driver.
> > + *
> > + * ------------------------------------------------------------------------
> > + * | n * 512 blocks | extra | ecc | |
> > + * | | block | codes | |
> > + *
> > +---------------------------------------------------------------------
> > +---
> > + *
> > + * The ECC calculation uses a simple Hamming code, using 1-bit
> > +correction 2-bit
> > + * detection. It starts when a valid read or write command with a 512
> > +byte
> > + * aligned address is detected on the memory interface.
> > + *
> > + * Return: 0 on success or error value on failure
> > + */
> > +static int pl353_nand_calculate_hwecc(struct mtd_info *mtd,
> > + const u8 *data, u8 *ecc)
> > +{
> > + u32 ecc_value;
> > + u8 ecc_reg, ecc_byte, ecc_status;
> > + unsigned long timeout = jiffies + PL353_NAND_ECC_BUSY_TIMEOUT;
> > +
> > + /* Wait till the ECC operation is complete or timeout */
> > + do {
> > + if (pl353_smc_ecc_is_busy())
> > + cpu_relax();
> > + else
> > + break;
> > + } while (!time_after_eq(jiffies, timeout));
> > +
> > + if (time_after_eq(jiffies, timeout)) {
> > + pr_err("%s timed out\n", __func__);
> > + return -ETIMEDOUT;
> > + }
>
> All of this should be done by the function calling nand_calculate_hwecc(), not here.
Ok, I will update it.
>
> Plus, it should deserve a function on its own.
Ok, will add new one.
>
> > +
> > + for (ecc_reg = 0; ecc_reg < 4; ecc_reg++) {
> > + /* Read ECC value for each block */
>
> So you assume here that there are 4, and only 4 "blocks" (I prefer "ECC chunks" or
> "subpages"). Is it always the case? Or is it just how it works in your situation? I would rather
> prefer a to define this value anyway.
Sure, I will define a macro as ECC chunks to represent 4.
And there are always 4 ECC registers as per the controller. And there is no assumption here.

>
> > + ecc_value = pl353_smc_get_ecc_val(ecc_reg);
> > + ecc_status = (ecc_value >> PL353_NAND_ECC_VALID_SHIFT);
>
> Space
Hmm. I will correct it.
>
> > + /* ECC value valid */
> > + if (ecc_status & PL353_NAND_ECC_VALID_MASK) {
> > + for (ecc_byte = 0; ecc_byte < 3; ecc_byte++) {
>
> Define 3
Ok, I will update it.
>
> > + /* Copy ECC bytes to MTD buffer */
> > + *ecc = ~ecc_value & 0xFF;
> > + ecc_value = ecc_value >> 8;
> > + ecc++;
> > + }
> > + } else {
> > + pr_warn("%s status failed\n", __func__);
> > + return -1;
> > + }
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_correct_data - ECC correction function
> > + * @mtd: Pointer to the mtd_info structure
> > + * @buf: Pointer to the page data
> > + * @read_ecc: Pointer to the ECC value read from spare data area
> > + * @calc_ecc: Pointer to the calculated ECC value
> > + *
> > + * This function corrects the ECC single bit errors & detects 2-bit errors.
> > + *
> > + * Return: 0 if no ECC errors found
> > + * 1 if single bit error found and corrected.
> > + * -1 if multiple uncorrectable ECC errors found.
> > + */
> > +static int pl353_nand_correct_data(struct mtd_info *mtd, unsigned char *buf,
> > + unsigned char *read_ecc,
> > + unsigned char *calc_ecc)
> > +{
> > + unsigned char bit_addr;
> > + unsigned int byte_addr;
> > + unsigned short ecc_odd, ecc_even, read_ecc_lower, read_ecc_upper;
> > + unsigned short calc_ecc_lower, calc_ecc_upper;
> > +
> > + read_ecc_lower = (read_ecc[0] | (read_ecc[1] << 8)) &
> > + PL353_ECC_BIT_MASK;
> > + read_ecc_upper = ((read_ecc[1] >> 4) | (read_ecc[2] << 4)) &
> > + PL353_ECC_BIT_MASK;
> > +
> > + calc_ecc_lower = (calc_ecc[0] | (calc_ecc[1] << 8)) &
> > + PL353_ECC_BIT_MASK;
> > + calc_ecc_upper = ((calc_ecc[1] >> 4) | (calc_ecc[2] << 4)) &
> > + PL353_ECC_BIT_MASK;
> > +
> > + ecc_odd = read_ecc_lower ^ calc_ecc_lower;
> > + ecc_even = read_ecc_upper ^ calc_ecc_upper;
> > +
> > + /* no error */
> > + if (!ecc_odd && !ecc_even)
> > + return 0;
> > +
> > + if (ecc_odd == (~ecc_even & PL353_ECC_BIT_MASK)) {
> > + /* bits [11:3] of error code is byte offset */
> > + byte_addr = (ecc_odd >> 3) & PL353_ECC_BITS_BYTEOFF_MASK;
> > + /* bits [2:0] of error code is bit offset */
> > + bit_addr = ecc_odd & PL353_ECC_BITS_BITOFF_MASK;
> > + /* Toggling error bit */
> > + buf[byte_addr] ^= (BIT(bit_addr));
> > + return 1;
> > + }
> > +
> > + /* one error in parity */
> > + if (hweight32(ecc_odd | ecc_even) == 1)
> > + return 1;
> > +
> > + /* Uncorrectable error */
> > + return -1;
> > +}
> > +
> > +static void pl353_prepare_cmd(struct mtd_info *mtd, struct nand_chip *chip,
> > + int page, int column, int start_cmd, int end_cmd,
> > + bool read)
> > +{
> > + unsigned long data_phase_addr;
> > + u32 end_cmd_valid = 0;
> > + unsigned long cmd_phase_addr = 0, cmd_data = 0;
> > +
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > +
> > + end_cmd_valid = read ? 1 : 0;
> > +
> > + cmd_phase_addr = (unsigned long __force)xnfc->nand_base +
>
> do you really need this cast?
As I said above, during command and data phases, we have to update the AXI Read/Write addresses with cycles, start command, end command
And some extra info. Hence I am converting it to a value and then adding the above values and then again converting back as an
Address.

>
> > + ((xnfc->addr_cycles
> > + << ADDR_CYCLES_SHIFT) |
> > + (end_cmd_valid << END_CMD_VALID_SHIFT) |
> > + (COMMAND_PHASE) |
> > + (end_cmd << END_CMD_SHIFT) |
> > + (start_cmd << START_CMD_SHIFT));
>
> So the number of address cycles changes the address where you should write the address
> cycles? that's weird, no?
I agree, but the implementation of PL353 is like that.
As I pointed the spec above, for every transfer we have to frame AXI Write address and Read address.

>
> > +
> > + /* Get the data phase address */
> > + data_phase_addr = (unsigned long __force)xnfc->nand_base +
> > + ((0x0 << CLEAR_CS_SHIFT) |
> > + (0 << END_CMD_VALID_SHIFT) |
> > + (DATA_PHASE) |
> > + (end_cmd << END_CMD_SHIFT) |
> > + (0x0 << ECC_LAST_SHIFT));
> > +
> Same question here?
>
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
>
> This should be done only once in the probe
No, as explained above, once we frame the Axi Write address/Read address with valid data, then we
Are converting back as memory address with the casting.
Do you see any issues with that?
Let me know, is there an alternative to achieve the same.
All is about, constructing AXI Write address and Read address during command and data phases.
>
> > +
> > + if (chip->options & NAND_BUSWIDTH_16)
> > + column /= 2;
> > + cmd_data = column;
>
> Please rename cmd_data because assigning a column (ie, an address
> cycle) to a variable name "cmd_data" is weird.
Ok, I will change it.
>
> > + if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> > + cmd_data |= page << 16;
> > + /* Another address cycle for devices > 128MiB */
> > + if (chip->options & NAND_ROW_ADDR_3) {
> > + writel_relaxed(cmd_data,
> > + (void __iomem * __force)cmd_phase_addr);
> > + cmd_data = (page >> 16);
> > + }
> > + } else {
> > + cmd_data |= page << 8;
> > + }
> > +
> > + writel_relaxed(cmd_data, (void __iomem * __force)cmd_phase_addr); }
> > +
> > +/**
> > + * pl353_nand_read_oob - [REPLACEABLE] the most common OOB data read function
> > + * @mtd: Pointer to the mtd info structure
>
> NAND and MTD are always upper case in plain english. Here I suppose you refer to the
> structure name, the use the exact name "mtd_info".
Ok, I will correct it.
>
>
> > + * @chip: Pointer to the NAND chip info structure
> > + * @page: Page number to read
> > + *
> > + * Return: Always return zero
> > + */
> > +static int pl353_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
> > + int page)
> > +{
> > + unsigned long data_phase_addr;
> > + u8 *p;
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > + unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +
> > + chip->pagebuf = -1;
> > + if (mtd->writesize < PL353_NAND_ECC_SIZE)
> > + return 0;
> > +
> > + pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_READ0,
> > + NAND_CMD_READSTART, 1);
> > +
> > + nand_wait_ready(mtd);
> > +
> > + p = chip->oob_poi;
> > + pl353_nand_read_data_op(chip, p,
> > + (mtd->oobsize -
> > + PL353_NAND_LAST_TRANSFER_LENGTH));
> > + p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > + data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > + data_phase_addr -= nand_offset;
> > + data_phase_addr |= PL353_NAND_CLEAR_CS;
> > + data_phase_addr += nand_offset;
>
> This is still a foreign language for me, why do you do the math everytime? And please explain
> what's done here, it's absolutely not clear for me.
Explained above.
>
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
>
> You should not need the cast.
>
> > + pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_write_oob - [REPLACEABLE] the most common OOB data write
> function
> > + * @mtd: Pointer to the mtd info structure
> > + * @chip: Pointer to the NAND chip info structure
> > + * @page: Page number to write
> > + *
> > + * Return: Zero on success and EIO on failure
> > + */
> > +static int pl353_nand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
> > + int page)
> > +{
> > + const u8 *buf = chip->oob_poi;
> > + unsigned long data_phase_addr;
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > + unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > + u32 addrcycles = 0;
> > +
> > + chip->pagebuf = -1;
> > + addrcycles = xnfc->addr_cycles;
> > + pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_SEQIN,
> > + NAND_CMD_PAGEPROG, 0);
> > +
> > + pl353_nand_write_data_op(mtd, buf,
> > + (mtd->oobsize -
> > + PL353_NAND_LAST_TRANSFER_LENGTH));
> > + buf += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > + data_phase_addr -= nand_offset;
> > + data_phase_addr |= PL353_NAND_CLEAR_CS;
> > + data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> > + data_phase_addr += nand_offset;
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > + pl353_nand_write_data_op(mtd, buf,
> PL353_NAND_LAST_TRANSFER_LENGTH);
> > + nand_wait_ready(mtd);
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_read_page_raw - [Intern] read raw page data without ecc
> > + * @mtd: Pointer to the mtd info structure
> > + * @chip: Pointer to the NAND chip info structure
> > + * @buf: Pointer to the data buffer
> > + * @oob_required: Caller requires OOB data read to chip->oob_poi
> > + * @page: Page number to read
> > + *
> > + * Return: Always return zero
> > + */
> > +static int pl353_nand_read_page_raw(struct mtd_info *mtd,
> > + struct nand_chip *chip,
> > + u8 *buf, int oob_required, int page) {
> > + unsigned long data_phase_addr;
> > + u8 *p;
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > + unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +
> > + pl353_nand_read_data_op(chip, buf, mtd->writesize);
> > + p = chip->oob_poi;
> > + pl353_nand_read_data_op(chip, p,
> > + (mtd->oobsize -
> > + PL353_NAND_LAST_TRANSFER_LENGTH));
> > + p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > + data_phase_addr -= nand_offset;
> > + data_phase_addr |= PL353_NAND_CLEAR_CS;
> > + data_phase_addr += nand_offset;
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +
> > + pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_write_page_raw - [Intern] raw page write function
> > + * @mtd: Pointer to the mtd info structure
> > + * @chip: Pointer to the NAND chip info structure
> > + * @buf: Pointer to the data buffer
> > + * @oob_required: Caller requires OOB data read to chip->oob_poi
> > + * @page: Page number to write
> > + *
> > + * Return: Always return zero
> > + */
> > +static int pl353_nand_write_page_raw(struct mtd_info *mtd,
> > + struct nand_chip *chip,
> > + const u8 *buf, int oob_required,
> > + int page)
> > +{
> > + unsigned long data_phase_addr;
> > + u8 *p;
> > +
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > + unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +
> > + pl353_nand_write_data_op(mtd, buf, mtd->writesize);
> > + p = chip->oob_poi;
> > + pl353_nand_write_data_op(mtd, p,
> > + (mtd->oobsize -
> > + PL353_NAND_LAST_TRANSFER_LENGTH));
> > + p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > + data_phase_addr -= nand_offset;
> > + data_phase_addr |= PL353_NAND_CLEAR_CS;
> > + data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> > + data_phase_addr += nand_offset;
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > + pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * nand_write_page_hwecc - Hardware ECC based page write function
> > + * @mtd: Pointer to the mtd info structure
> > + * @chip: Pointer to the NAND chip info structure
> > + * @buf: Pointer to the data buffer
> > + * @oob_required: Caller requires OOB data read to chip->oob_poi
> > + * @page: Page number to write
> > + *
> > + * This functions writes data and hardware generated ECC values in to the page.
> > + *
> > + * Return: Always return zero
> > + */
> > +static int pl353_nand_write_page_hwecc(struct mtd_info *mtd,
> > + struct nand_chip *chip,
> > + const u8 *buf, int oob_required,
> > + int page)
> > +{
> > + int eccsize = chip->ecc.size;
> > + int eccsteps = chip->ecc.steps;
> > + u8 *ecc_calc = chip->ecc.calc_buf;
> > + u8 *oob_ptr;
> > + const u8 *p = buf;
> > + u32 ret;
> > + unsigned long data_phase_addr;
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > + unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +
> > + pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_SEQIN,
> > + NAND_CMD_PAGEPROG, 0);
> > +
> > + for ( ; (eccsteps - 1); eccsteps--) {
> > + pl353_nand_write_data_op(mtd, p, eccsize);
> > + p += eccsize;
> > + }
> > + pl353_nand_write_data_op(mtd, p,
> > + (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
> > + p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + /* Set ECC Last bit to 1 */
> > + data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > + data_phase_addr -= nand_offset;
> > + data_phase_addr |= PL353_NAND_ECC_LAST;
> > + data_phase_addr += nand_offset;
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > + pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + p = buf;
> > + chip->ecc.calculate(mtd, p, &ecc_calc[0]);
>
> You should check the returned value?
Ok, I will update it.
>
> > +
> > + /* Wait for ECC to be calculated and read the error values */
> > + ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi,
> > + 0, chip->ecc.total);
> > + if (ret)
> > + return ret;
> > + /* Clear ECC last bit */
> > + data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > + data_phase_addr -= nand_offset;
> > + data_phase_addr &= ~PL353_NAND_ECC_LAST;
> > + data_phase_addr += nand_offset;
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +
> > + /* Write the spare area with ECC bytes */
> > + oob_ptr = chip->oob_poi;
> > + pl353_nand_write_data_op(mtd, oob_ptr,
> > + (mtd->oobsize -
> > + PL353_NAND_LAST_TRANSFER_LENGTH));
> > +
> > + data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > + data_phase_addr -= nand_offset;
> > + data_phase_addr |= PL353_NAND_CLEAR_CS;
> > + data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> > + data_phase_addr += nand_offset;
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > + oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > + pl353_nand_write_data_op(mtd, oob_ptr,
> PL353_NAND_LAST_TRANSFER_LENGTH);
> > + nand_wait_ready(mtd);
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_read_page_hwecc - Hardware ECC based page read function
> > + * @mtd: Pointer to the mtd info structure
> > + * @chip: Pointer to the NAND chip info structure
> > + * @buf: Pointer to the buffer to store read data
> > + * @oob_required: Caller requires OOB data read to chip->oob_poi
> > + * @page: Page number to read
> > + *
> > + * This functions reads data and checks the data integrity by
> > +comparing
> > + * hardware generated ECC values and read ECC values from spare area.
> > + * There is a limitation in SMC controller, that we must set ECC LAST
> > +on
> > + * last data phase access, to tell ECC block not to expect any data further.
> > + * Ex: When number of ECC STEPS are 4, then till 3 we will write to
> > +flash
> > + * using SMC with HW ECC enabled. And for the last ECC STEP, we will
> > +subtract
> > + * 4bytes from page size, and will initiate a transfer. And the
> > +remaining 4 as
> > + * one more transfer with ECC_LAST bit set in NAND data phase
> > +register to
> > + * notify ECC block not to expect any more data. The last block
> > +should be align
> > + * with end of 512 byte block. Because of this limitation, we are not
> > +using
> > + * core routines.
> > + *
> > + * Return: 0 always and updates ECC operation status in to MTD structure
> > + */
> > +static int pl353_nand_read_page_hwecc(struct mtd_info *mtd,
> > + struct nand_chip *chip,
> > + u8 *buf, int oob_required, int page) {
> > + int i, stat, eccsize = chip->ecc.size;
> > + int eccbytes = chip->ecc.bytes;
> > + int eccsteps = chip->ecc.steps;
> > + u8 *p = buf;
> > + u8 *ecc_calc = chip->ecc.calc_buf;
> > + u8 *ecc = chip->ecc.code_buf;
> > + unsigned int max_bitflips = 0;
> > + u8 *oob_ptr;
> > + u32 ret;
> > + unsigned long data_phase_addr;
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > + unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +
> > + pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_READ0,
> > + NAND_CMD_READSTART, 1);
> > + nand_wait_ready(mtd);
> > +
> > + for ( ; (eccsteps - 1); eccsteps--) {
> > + pl353_nand_read_data_op(chip, p, eccsize);
> > + p += eccsize;
> > + }
> > + pl353_nand_read_data_op(chip, p,
> > + (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
> > + p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + /* Set ECC Last bit to 1 */
> > + data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > + data_phase_addr -= nand_offset;
> > + data_phase_addr |= PL353_NAND_ECC_LAST;
> > + data_phase_addr += nand_offset;
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > + pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + /* Read the calculated ECC value */
> > + p = buf;
> > + chip->ecc.calculate(mtd, p, &ecc_calc[0]);
> > +
>
> You should check the returned value?
Ok, I will update it.

>
> > + /* Clear ECC last bit */
> > + data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > + data_phase_addr -= nand_offset;
> > + data_phase_addr &= ~PL353_NAND_ECC_LAST;
> > + data_phase_addr += nand_offset;
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +
> > + /* Read the stored ECC value */
> > + oob_ptr = chip->oob_poi;
> > + pl353_nand_read_data_op(chip, oob_ptr,
> > + (mtd->oobsize -
> > + PL353_NAND_LAST_TRANSFER_LENGTH));
> > +
> > + /* de-assert chip select */
> > + data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > + data_phase_addr -= nand_offset;
> > + data_phase_addr |= PL353_NAND_CLEAR_CS;
> > + data_phase_addr += nand_offset;
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +
> > + oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > + pl353_nand_read_data_op(chip, oob_ptr,
> > +PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > + ret = mtd_ooblayout_get_eccbytes(mtd, ecc, chip->oob_poi, 0,
> > + chip->ecc.total);
> > + if (ret)
> > + return ret;
> > +
> > + eccsteps = chip->ecc.steps;
> > + p = buf;
> > +
> > + /* Check ECC error for all blocks and correct if it is correctable */
> > + for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
> > + stat = chip->ecc.correct(mtd, p, &ecc[i], &ecc_calc[i]);
> > + if (stat < 0) {
> > + mtd->ecc_stats.failed++;
> > + } else {
> > + mtd->ecc_stats.corrected += stat;
> > + max_bitflips = max_t(unsigned int, max_bitflips, stat);
> > + }
> > + }
> > +
> > + return max_bitflips;
> > +}
> > +
> > +/**
> > + * pl353_nand_select_chip - Select the flash device
> > + * @mtd: Pointer to the mtd info structure
> > + * @chip: Pointer to the NAND chip info structure
> > + *
> > + * This function is empty as the NAND controller handles chip select
> > +line
> > + * internally based on the chip address passed in command and data phase.
> > + */
> > +static void pl353_nand_select_chip(struct mtd_info *mtd, int chip) {
> > +}
> > +
> > +/* NAND framework ->exec_op() hooks and related helpers */ static
> > +void pl353_nfc_parse_instructions(struct nand_chip *chip,
> > + const struct nand_subop *subop,
> > + struct pl353_nfc_op *nfc_op)
> > +{
> > + const struct nand_op_instr *instr = NULL;
> > + unsigned int op_id, offset, naddrs;
> > + int i, len;
> > + const u8 *addrs;
> > +
> > + memset(nfc_op, 0, sizeof(struct pl353_nfc_op));
> > + for (op_id = 0; op_id < subop->ninstrs; op_id++) {
> > + nfc_op->len = nand_subop_get_data_len(subop, op_id);
> > + len = nand_subop_get_data_len(subop, op_id);
> > + instr = &subop->instrs[op_id];
> > +
> > + switch (instr->type) {
> > + case NAND_OP_CMD_INSTR:
> > + nfc_op->type = NAND_OP_CMD_INSTR;
> > + if (op_id)
> > + nfc_op->cmnds[1] = instr->ctx.cmd.opcode;
> > + else
> > + nfc_op->cmnds[0] = instr->ctx.cmd.opcode;
> > + nfc_op->cle_ale_delay_ns = instr->delay_ns;
> > + break;
> > +
> > + case NAND_OP_ADDR_INSTR:
> > + offset = nand_subop_get_addr_start_off(subop, op_id);
> > + naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
> > + addrs = &instr->ctx.addr.addrs[offset];
> > + nfc_op->addrs = instr->ctx.addr.addrs[offset];
> > + for (i = 0; i < min_t(unsigned int, 4, naddrs); i++) {
> > + nfc_op->addrs |= instr->ctx.addr.addrs[i] <<
> > + (8 * i);
> > + }
> > +
> > + if (naddrs >= 5)
> > + nfc_op->addr5 = addrs[4];
> > + if (naddrs >= 6)
> > + nfc_op->addr6 = addrs[5];
> > + nfc_op->naddrs = nand_subop_get_num_addr_cyc(subop,
> > + op_id);
> > + nfc_op->cle_ale_delay_ns = instr->delay_ns;
> > + break;
> > +
> > + case NAND_OP_DATA_IN_INSTR:
> > + nfc_op->data_instr = instr;
> > + nfc_op->type = NAND_OP_DATA_IN_INSTR;
> > + nfc_op->data_instr_idx = op_id;
> > + break;
> > +
> > + case NAND_OP_DATA_OUT_INSTR:
> > + nfc_op->data_instr = instr;
> > + nfc_op->type = NAND_OP_DATA_IN_INSTR;
> > + nfc_op->data_instr_idx = op_id;
> > + break;
> > +
> > + case NAND_OP_WAITRDY_INSTR:
> > + nfc_op->rdy_timeout_ms = instr->ctx.waitrdy.timeout_ms;
> > + nfc_op->rdy_delay_ns = instr->delay_ns;
> > + break;
> > + }
> > + }
> > +}
> > +
> > +static void cond_delay(unsigned int ns) {
> > + if (!ns)
> > + return;
> > +
> > + if (ns < 10000)
> > + ndelay(ns);
> > + else
> > + udelay(DIV_ROUND_UP(ns, 1000));
> > +}
> > +
> > +/**
> > + * pl353_nand_cmd_function - Send command to NAND device
> > + * @chip: Pointer to the NAND chip info structure
> > + * @subop: Pointer to array of instructions
> > + * Return: Always return zero
> > + */
> > +static int pl353_nand_cmd_function(struct nand_chip *chip,
> > + const struct nand_subop *subop)
>
> Please don't use this name, too close from the cmdfunc() hook we are trying to remove.
Sure, I will change it.

>
> > +{
> > + struct mtd_info *mtd = nand_to_mtd(chip);
> > + const struct nand_op_instr *instr;
> > + struct pl353_nfc_op nfc_op = {};
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > + unsigned long cmd_data = 0, end_cmd_valid = 0;
> > + unsigned long cmd_phase_addr, data_phase_addr, end_cmd;
> > + unsigned int op_id, len, offset;
> > + bool reading;
> > +
> > + pl353_nfc_parse_instructions(chip, subop, &nfc_op);
> > + instr = nfc_op.data_instr;
> > + op_id = nfc_op.data_instr_idx;
> > + len = nand_subop_get_data_len(subop, op_id);
> > + offset = nand_subop_get_data_start_off(subop, op_id);
> > +
> > + pl353_smc_clr_nand_int();
> > + /* Get the command phase address */
> > + if (nfc_op.cmnds[1] != 0) {
> > + if (nfc_op.cmnds[0] == NAND_CMD_SEQIN)
> > + end_cmd_valid = 0;
> > + else
> > + end_cmd_valid = 1;
> > + end_cmd = nfc_op.cmnds[1];
> > + } else {
> > + end_cmd = 0x0;
> > + }
> > +
> > + /*
> > + * The SMC defines two phases of commands when transferring data to or
> > + * from NAND flash.
> > + * Command phase: Commands and optional address information are written
> > + * to the NAND flash.The command and address can be associated with
> > + * either a data phase operation to write to or read from the array,
> > + * or a status/ID register transfer.
> > + * Data phase: Data is either written to or read from the NAND flash.
> > + * This data can be either data transferred to or from the array,
> > + * or status/ID register information.
> > + */
> > + cmd_phase_addr = (unsigned long __force)xnfc->nand_base +
> > + ((nfc_op.naddrs << ADDR_CYCLES_SHIFT) |
> > + (end_cmd_valid << END_CMD_VALID_SHIFT) |
> > + (COMMAND_PHASE) |
> > + (end_cmd << END_CMD_SHIFT) |
> > + (nfc_op.cmnds[0] << START_CMD_SHIFT));
> > +
> > + /* Get the data phase address */
> > + end_cmd_valid = 0;
> > +
> > + data_phase_addr = (unsigned long __force)xnfc->nand_base +
> > + ((0x0 << CLEAR_CS_SHIFT) |
> > + (end_cmd_valid << END_CMD_VALID_SHIFT) |
> > + (DATA_PHASE) |
> > + (end_cmd << END_CMD_SHIFT) |
> > + (0x0 << ECC_LAST_SHIFT));
> > + xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +
> > + /* Command phase AXI Read & Write */
> > + if (nfc_op.naddrs >= 5) {
> > + if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> > + cmd_data = nfc_op.addrs;
> > + /* Another address cycle for devices > 128MiB */
> > + if (chip->options & NAND_ROW_ADDR_3) {
> > + writel_relaxed(cmd_data,
> > + (void __iomem * __force)
> > + cmd_phase_addr);
> > + cmd_data = nfc_op.addr5;
> > + if (nfc_op.naddrs >= 6)
> > + cmd_data |= (nfc_op.addr6 << 8);
> > + }
> > + }
> > + } else {
> > + if (nfc_op.addrs != -1) {
> > + int column = nfc_op.addrs;
> > + /*
> > + * Change read/write column, read id etc
> > + * Adjust columns for 16 bit bus width
> > + */
> > + if ((chip->options & NAND_BUSWIDTH_16) &&
> > + (nfc_op.cmnds[0] == NAND_CMD_READ0 ||
> > + nfc_op.cmnds[0] == NAND_CMD_SEQIN ||
> > + nfc_op.cmnds[0] == NAND_CMD_RNDOUT ||
> > + nfc_op.cmnds[0] == NAND_CMD_RNDIN)) {
> > + column >>= 1;
> > + }
> > + cmd_data = column;
> > + }
> > + }
> > + writel_relaxed(cmd_data, (void __iomem * __force)cmd_phase_addr);
> > +
> > + if (!nfc_op.data_instr) {
> > + if (nfc_op.rdy_timeout_ms)
> > + nand_wait_ready(mtd);
> > + return 0;
> > + }
> > +
> > + reading = (nfc_op.data_instr->type == NAND_OP_DATA_IN_INSTR);
> > + if (!reading) {
> > + if (nfc_op.cmnds[0] == NAND_CMD_SEQIN &&
> > + nfc_op.cmnds[1] == NAND_CMD_PAGEPROG) {
> > + pl353_nand_write_page_raw(mtd, chip,
> > + instr->ctx.data.buf.out, 0,
> > + nfc_op.addrs);
> > +
> > + } else {
> > + pl353_nand_write_data_op(mtd, instr->ctx.data.buf.out,
> > + len);
> > + }
> > + if (nfc_op.rdy_timeout_ms)
> > + nand_wait_ready(mtd);
> > + cond_delay(nfc_op.rdy_delay_ns);
> > + }
> > + if (reading) {
> > + cond_delay(nfc_op.rdy_delay_ns);
> > + if (nfc_op.rdy_timeout_ms)
> > + nand_wait_ready(mtd);
> > + pl353_nand_read_data_op(chip, instr->ctx.data.buf.in, len);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static const struct nand_op_parser pl353_nfc_op_parser = NAND_OP_PARSER
> > + (NAND_OP_PARSER_PATTERN
> > + (pl353_nand_cmd_function,
> > + NAND_OP_PARSER_PAT_CMD_ELEM(true),
> > + NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
> > + NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
> > + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> > + NAND_OP_PARSER_PATTERN
> > + (pl353_nand_cmd_function,
> > + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > + NAND_OP_PARSER_PAT_ADDR_ELEM(false, 7),
> > + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > + NAND_OP_PARSER_PAT_WAITRDY_ELEM(false),
> > + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> > + NAND_OP_PARSER_PATTERN
> > + (pl353_nand_cmd_function,
> > + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > + NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
> > + NAND_OP_PARSER_PAT_CMD_ELEM(true),
> > + NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> > + NAND_OP_PARSER_PATTERN
> > + (pl353_nand_cmd_function,
> > + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > + NAND_OP_PARSER_PAT_ADDR_ELEM(false, 8),
> > + NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 2048),
> > + NAND_OP_PARSER_PAT_CMD_ELEM(true),
> > + NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
> > + NAND_OP_PARSER_PATTERN
> > + (pl353_nand_cmd_function,
> > + NAND_OP_PARSER_PAT_CMD_ELEM(false)),
> > + );
> > +
> > +static int pl353_nfc_exec_op(struct nand_chip *chip,
> > + const struct nand_operation *op,
> > + bool check_only)
> > +{
> > + return nand_op_parser_exec_op(chip, &pl353_nfc_op_parser,
> > + op, check_only);
> > +}
> > +
> > +/**
> > + * pl353_nand_device_ready - Check device ready/busy line
> > + * @mtd: Pointer to the mtd_info structure
> > + *
> > + * Return: 0 on busy or 1 on ready state
> > + */
> > +static int pl353_nand_device_ready(struct mtd_info *mtd {
> > + if (pl353_smc_get_nand_int_status_raw()) {
> > + pl353_smc_clr_nand_int();
> > + return 1;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_ecc_init - Initialize the ecc information as per the ecc mode
> > + * @mtd: Pointer to the mtd_info structure
> > + * @ecc: Pointer to ECC control structure
> > + * @ecc_mode: ondie ecc status
> > + *
> > + * This function initializes the ecc block and functional pointers as
> > +per the
> > + * ecc mode
> > + *
> > + * Return: 0 on success or negative errno.
> > + */
> > +static int pl353_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
> > + int ecc_mode)
> > +{
> > + struct nand_chip *chip = mtd_to_nand(mtd);
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > + int err = 0;
> > +
> > + if (ecc_mode == NAND_ECC_ON_DIE) {
> > + pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_BYPASS);
> > + /*
> > + * On-Die ECC spare bytes offset 8 is used for ECC codes
> > + * Use the BBT pattern descriptors
> > + */
> > + chip->bbt_td = &bbt_main_descr;
> > + chip->bbt_md = &bbt_mirror_descr;
> > + bitmap_set(chip->parameters.get_feature_list,
> > + ONFI_FEATURE_ON_DIE_ECC,
> ONFI_FEATURE_ON_DIE_ECC_EN);
> > + bitmap_set(chip->parameters.set_feature_list,
> > + ONFI_FEATURE_ON_DIE_ECC,
> ONFI_FEATURE_ON_DIE_ECC_EN);
> > + } else {
> > + ecc->read_oob = pl353_nand_read_oob;
> > + ecc->write_oob = pl353_nand_write_oob;
> > +
> > + ecc->mode = NAND_ECC_HW;
> > + /* Hardware ECC generates 3 bytes ECC code for each 512 bytes */
> > + ecc->bytes = 3;
> > + ecc->strength = 1;
> > + ecc->calculate = pl353_nand_calculate_hwecc;
> > + ecc->correct = pl353_nand_correct_data;
> > + ecc->read_page = pl353_nand_read_page_hwecc;
> > + ecc->size = PL353_NAND_ECC_SIZE;
> > + ecc->write_page = pl353_nand_write_page_hwecc;
> > + pl353_smc_set_ecc_pg_size(mtd->writesize);
> > + switch (mtd->writesize) {
> > + case SZ_512:
> > + case SZ_1K:
> > + case SZ_2K:
> > + pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_APB);
> > + break;
> > + default:
> > + ecc->calculate = nand_calculate_ecc;
> > + ecc->correct = nand_correct_data;
> > + ecc->size = 256;
> > + break;
> > + }
> > + if (mtd->writesize <= SZ_512)
> > + xnfc->addr_cycles = 1;
> > + else
> > + xnfc->addr_cycles = 2;
> > +
> > + if (chip->options & NAND_ROW_ADDR_3)
> > + xnfc->addr_cycles += 3;
> > + else
> > + xnfc->addr_cycles += 2;
> > +
> > + if (mtd->oobsize == 16) {
> > + mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout16_ops);
> > + } else if (mtd->oobsize == 64) {
> > + mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout64_ops);
> > + } else {
> > + err = -ENXIO;
> > + dev_err(xnfc->dev, "Unsupported oob Layout\n");
> > + }
> > + }
> > + return err;
> > +}
> > +
> > +static int pl353_setup_data_interface(struct mtd_info *mtd, int csline,
> > + const struct nand_data_interface *conf) {
> > + struct nand_chip *chip = mtd_to_nand(mtd);
> > + struct pl353_nand_info *xnfc =
> > + container_of(chip, struct pl353_nand_info, chip);
> > + const struct nand_sdr_timings *sdr;
> > + u32 timings[7], mckperiodps;
> > +
> > + sdr = nand_get_sdr_timings(conf);
> > + if (IS_ERR(sdr))
> > + return PTR_ERR(sdr);
> > +
> > + /*
> > + * SDR timings are given in pico-seconds while NFC timings must be
> > + * expressed in NAND controller clock cycles.
> > + */
> > + mckperiodps = NSEC_PER_SEC / clk_get_rate(xnfc->mclk);
> > + mckperiodps *= 1000;
> > + if (sdr->tRC_min <= 20000)
> > + /*
> > + * PL353 SMC needs one extra read cycle in SDR Mode 5
> > + * This is not written anywhere in the datasheet but
> > + * the results observed during testing.
>
> Oh, that's bad.
>
> > + */
> > + timings[0] = DIV_ROUND_UP(sdr->tRC_min, mckperiodps) + 1;
> > + else
> > + timings[0] = DIV_ROUND_UP(sdr->tRC_min, mckperiodps);
> > +
> > + timings[1] = DIV_ROUND_UP(sdr->tWC_min, mckperiodps);
> > + /*
> > + * For all SDR modes, PL353 SMC needs tREA max value as 1
> > + * These results observed during testing.
>
> s/These results/Results/
Ok, will update.
>
> > + */
> > + timings[2] = PL353_TREA_MAX_VALUE;
> > + timings[3] = DIV_ROUND_UP(sdr->tWP_min, mckperiodps);
> > + timings[4] = DIV_ROUND_UP(sdr->tCLR_min, mckperiodps);
> > + timings[5] = DIV_ROUND_UP(sdr->tAR_min, mckperiodps);
> > + timings[6] = DIV_ROUND_UP(sdr->tRR_min, mckperiodps);
> > +
> > + if (csline == NAND_DATA_IFACE_CHECK_ONLY)
> > + return 0;
>
> You should move this to the top.
Ok, I will change it.
>
> > +
> > + pl353_smc_set_cycles(timings);
> > +
> > + return 0;
> > +}
> > +/**
> > + * pl353_nand_probe - Probe method for the NAND driver
> > + * @pdev: Pointer to the platform_device structure
> > + *
> > + * This function initializes the driver data structures and the hardware.
> > + * The NAND driver has dependency with the pl353_smc memory
> > +controller
> > + * driver for initializing the NAND timing parameters, bus width, ECC
> > +modes,
> > + * control and status information.
> > + *
> > + * Return: 0 on success or error value on failure
> > + */
> > +static int pl353_nand_probe(struct platform_device *pdev) {
> > + struct pl353_nand_info *xnfc;
> > + struct mtd_info *mtd;
> > + struct nand_chip *chip;
> > + struct resource *res;
> > + struct device_node *np;
> > + u32 ret;
> > +
> > + xnfc = devm_kzalloc(&pdev->dev, sizeof(*xnfc), GFP_KERNEL);
> > + if (!xnfc)
> > + return -ENOMEM;
> > + xnfc->dev = &pdev->dev;
> > + /* Map physical address of NAND flash */
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + xnfc->nand_base = devm_ioremap_resource(xnfc->dev, res);
> > + if (IS_ERR(xnfc->nand_base))
> > + return PTR_ERR(xnfc->nand_base);
> > +
> > + chip = &xnfc->chip;
> > + mtd = nand_to_mtd(chip);
> > + chip->exec_op = pl353_nfc_exec_op;
> > + nand_set_controller_data(chip, xnfc);
> > + mtd->priv = chip;
> > + mtd->owner = THIS_MODULE;
> > + if (!mtd->name) {
> > + /*
> > + * If the new bindings are used and the bootloader has not been
> > + * updated to pass a new mtdparts parameter on the cmdline, you
> > + * should define the following property in your NAND node, ie:
> > + *
> > + * label = "pl353-nand";
> > + *
> > + * This way, mtd->name will be set by the core when
> > + * nand_set_flash_node() is called.
> > + */
> > + mtd->name = devm_kasprintf(xnfc->dev, GFP_KERNEL,
> > + "%s", PL353_NAND_DRIVER_NAME);
> > + if (!mtd->name) {
> > + dev_err(xnfc->dev, "Failed to allocate mtd->name\n");
> > + return -ENOMEM;
> > + }
> > + }
> > + nand_set_flash_node(chip, xnfc->dev->of_node);
> > +
> > + /* Set the driver entry points for MTD */
> > + chip->dev_ready = pl353_nand_device_ready;
> > + chip->select_chip = pl353_nand_select_chip;
> > + /* If we don't set this delay driver sets 20us by default */
> > + np = of_get_next_parent(xnfc->dev->of_node);
> > + xnfc->mclk = of_clk_get(np, 0);
> > + if (IS_ERR(xnfc->mclk)) {
> > + dev_err(xnfc->dev, "Failed to retrieve MCK clk\n");
> > + return PTR_ERR(xnfc->mclk);
> > + }
> > + chip->chip_delay = 30;
> > + /* Set the device option and flash width */
> > + chip->options = NAND_BUSWIDTH_AUTO;
> > + chip->bbt_options = NAND_BBT_USE_FLASH;
> > + platform_set_drvdata(pdev, xnfc);
> > + chip->setup_data_interface = pl353_setup_data_interface;
> > + /* first scan to find the device and get the page size */
> > + if (nand_scan_ident(mtd, 1, NULL)) {
> > + dev_err(xnfc->dev, "nand_scan_ident for NAND failed\n");
> > + return -ENXIO;
> > + }
> > + ret = pl353_nand_ecc_init(mtd, &chip->ecc, chip->ecc.mode);
> > + if (chip->options & NAND_BUSWIDTH_16)
> > + pl353_smc_set_buswidth(PL353_SMC_MEM_WIDTH_16);
> > + /* second phase scan */
> > + if (nand_scan_tail(mtd)) {
> > + dev_err(xnfc->dev, "nand_scan_tail for NAND failed\n");
> > + return -ENXIO;
> > + }
> > +
>
> I suggest you to wait for v4.19-rc1 to be out and then rebase on top of it as this cycle we
> changed a lot of things.
>
> Particularly, nand_scan_ident() and nand_scan_tail() are not exposed anymore, you should
> create nand_controller_ops with an
> ->attach_chip() hook that does everything between ident() and tail()
> and use nand_scan() instead.
Sure Miquel, I will modify the driver as per v4.19-rc1, once it is out.
And thanks for you review again and thanks for your comments.
Compare to the initial version of this patch series, I think the current driver is in good shape now.
Thanks again for the review.

>
> > + ret = mtd_device_register(mtd, NULL, 0);
> > + if (ret) {
> > + dev_err(xnfc->dev, "Failed to register mtd device: %d\n", ret);
> > + nand_cleanup(chip);
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_remove - Remove method for the NAND driver
> > + * @pdev: Pointer to the platform_device structure
> > + *
> > + * This function is called if the driver module is being unloaded. It
> > +frees all
> > + * resources allocated to the device.
> > + *
> > + * Return: 0 on success or error value on failure
> > + */
> > +static int pl353_nand_remove(struct platform_device *pdev) {
> > + struct pl353_nand_info *xnfc = platform_get_drvdata(pdev);
> > + struct mtd_info *mtd = nand_to_mtd(&xnfc->chip);
> > +
> > + /* Release resources, unregister device */
> > + nand_release(mtd);
> > +
> > + return 0;
> > +}
> > +
> > +/* Match table for device tree binding */ static const struct
> > +of_device_id pl353_nand_of_match[] = {
> > + { .compatible = "arm,pl353-nand-r2p1" },
> > + {},
> > +};
> > +MODULE_DEVICE_TABLE(of, pl353_nand_of_match);
> > +
> > +/*
> > + * pl353_nand_driver - This structure defines the NAND subsystem
> > +platform driver */ static struct platform_driver pl353_nand_driver =
> > +{
> > + .probe = pl353_nand_probe,
> > + .remove = pl353_nand_remove,
> > + .driver = {
> > + .name = PL353_NAND_DRIVER_NAME,
> > + .of_match_table = pl353_nand_of_match,
> > + },
> > +};
> > +
> > +module_platform_driver(pl353_nand_driver);
> > +
> > +MODULE_AUTHOR("Xilinx, Inc.");
> > +MODULE_ALIAS("platform:" PL353_NAND_DRIVER_NAME);
> > +MODULE_DESCRIPTION("ARM PL353 NAND Flash Driver");
> > +MODULE_LICENSE("GPL");
>
>
> Thanks,
> MiquÃl

Regards,
Naga Sureshkumar Relli

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