Re: [v5 1/2] mtd: nand: Add new Cadence NAND driver to MTD subsystem

From: Miquel Raynal
Date: Sat Aug 24 2019 - 06:49:54 EST


Hi Dmitry,

Dmitry Osipenko <digetx@xxxxxxxxx> wrote on Thu, 25 Jul 2019 18:11:43
+0300:

> 25.07.2019 18:00, Piotr Sroka ÐÐÑÐÑ:
> > Add new Cadence NAND driver to MTD subsystem
> >
> > Signed-off-by: Piotr Sroka <piotrs@xxxxxxxxxxx>
> > ---
> > Changes for v5:
> > - fix "ecc config strength" field size
> > - remove unused macros
> > - fix address of timing2 register
> > - add guard for accessing data_control_size register
> > - simplify the driver by use the same function
> > for accessing main area and oob area
> > - add comment to the driver describing main controller modes
> > - change compatible name from cdns,hpnfc to cdns,hp-nfc
> > Changes for v4:
> > - fix comments issues like typos, missing capitals, missing dots etc.
> > - remove unnecessary PHY options phy_dll_aging and phy_per_bit_deskew
> > - replace all register access functions to "relaxed" version
> > - remove all unnecessary variables initializations
> > - handle error inside cadence_nand_get_ecc_strength_idx function in case
> > correnction strength is not found
> > - add commit message
> > Changes for v3:
> > - remove definitions of unused registers
> > - remove configuring registers which are not expected to be configured in
> > asynchronous mode
> > - remove not needed function reading timing registers
> > - remove information about oob size and write size from cdns_nand_chip type
> > and use vales from mtd_info directly
> > - use nand_cleanup instead of nand_release if mtd device is not registered yet
> > - fix cadence_nand_chips_init function add garbage collection
> > if a chip init fails
> > - simplify PHY calculations
> > Changes for v2:
> > - create one universal wait function for all events instead of one
> > function per event.
> > - split one big function executing nand operations to separate
> > functions one per each type of operation.
> > - add erase atomic operation to nand operation parser
> > - remove unnecessary includes.
> > - remove unused register defines
> > - add support for multiple nand chips
> > - remove all code using legacy functions
> > - remove chip dependents parameters from dts bindings, they were
> > attached to the SoC specific compatible at the driver level
> > - simplify interrupt handling
> > - simplify timing calculations
> > - fix calculation of maximum supported cs signals
> > - simplify ecc size calculation
> > - remove header file and put whole code to one c file
> > ---
> > drivers/mtd/nand/raw/Kconfig | 7 +
> > drivers/mtd/nand/raw/Makefile | 1 +
> > drivers/mtd/nand/raw/cadence-nand-controller.c | 3021 ++++++++++++++++++++++++
> > 3 files changed, 3029 insertions(+)
> > create mode 100644 drivers/mtd/nand/raw/cadence-nand-controller.c
> >
> > diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
> > index e604625e2dfa..4d2ce3b5b2ae 100644
> > --- a/drivers/mtd/nand/raw/Kconfig
> > +++ b/drivers/mtd/nand/raw/Kconfig
> > @@ -557,5 +557,12 @@ config MTD_NAND_MESON
> > help
> > Enables support for NAND controller on Amlogic's Meson SoCs.
> > This controller is found on Meson SoCs.
> > +config MTD_NAND_CADENCE
> > + tristate "Support Cadence NAND (HPNFC) controller"
> > + depends on OF
> > + help
> > + Enable the driver for NAND flash on platforms using a Cadence NAND
> > + controller.
> > +
> >
> > endif # MTD_NAND
> > diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
> > index 5a5a72f0793e..f4b099f276f7 100644
> > --- a/drivers/mtd/nand/raw/Makefile
> > +++ b/drivers/mtd/nand/raw/Makefile
> > @@ -58,6 +58,7 @@ obj-$(CONFIG_MTD_NAND_MTK) += mtk_ecc.o mtk_nand.o
> > obj-$(CONFIG_MTD_NAND_TEGRA) += tegra_nand.o
> > obj-$(CONFIG_MTD_NAND_STM32_FMC2) += stm32_fmc2_nand.o
> > obj-$(CONFIG_MTD_NAND_MESON) += meson_nand.o
> > +obj-$(CONFIG_MTD_NAND_CADENCE) += cadence-nand-controller.o
> >
> > nand-objs := nand_base.o nand_legacy.o nand_bbt.o nand_timings.o nand_ids.o
> > nand-objs += nand_onfi.o
> > diff --git a/drivers/mtd/nand/raw/cadence-nand-controller.c b/drivers/mtd/nand/raw/cadence-nand-controller.c
> > new file mode 100644
> > index 000000000000..a7ff4e4585d3
> > --- /dev/null
> > +++ b/drivers/mtd/nand/raw/cadence-nand-controller.c
> > @@ -0,0 +1,3021 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Cadence NAND flash controller driver
> > + *
> > + * Copyright (C) 2019 Cadence
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/clk.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/dmaengine.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/module.h>
> > +#include <linux/mtd/mtd.h>
> > +#include <linux/mtd/rawnand.h>
> > +#include <linux/of_device.h>
> > +#include <linux/iopoll.h>
> > +
> > +/*
> > + * HPNFC can work in 3 modes:
> > + * - PIO - can work in master or slave DMA.
> > + * - CDMA - needs Master DMA for accessing command descriptors.
> > + * - Generic mode - can use only slave DMA.
> > + * CDMA and PIO modes can be used to execute only base commands.
> > + * Generic mode can be used to execute any command
> > + * on NAND flash memory. Driver uses CDMA mode for
> > + * block erasing, page reading, page programing.
> > + * Generic mode is used for executing rest of commands.
> > + */
> > +
> > +#define MAX_OOB_SIZE_PER_SECTOR 32
> > +#define MAX_ADDRESS_CYC 6
> > +#define MAX_ERASE_ADDRESS_CYC 3
> > +#define MAX_DATA_SIZE 0xFFFC
> > +
> > +/* Register definition. */
> > +/*
> > + * Command register 0.
> > + * Writing data to this register will initiate a new transaction
> > + * of the NF controller.
> > + */
> > +#define CMD_REG0 0x0000
> > +/* Command type field mask. */
> > +#define CMD_REG0_CT GENMASK(31, 30)
> > +/* Command type CDMA. */
> > +#define CMD_REG0_CT_CDMA 0uL
> > +/* Command type generic. */
> > +#define CMD_REG0_CT_GEN 3uL
> > +/* Command thread number field mask. */
> > +#define CMD_REG0_TN GENMASK(27, 24)
> > +
> > +/* Command register 2. */
> > +#define CMD_REG2 0x0008
> > +/* Command register 3. */
> > +#define CMD_REG3 0x000C
> > +/* Pointer register to select which thread status will be selected. */
> > +#define CMD_STATUS_PTR 0x0010
> > +/* Command status register for selected thread. */
> > +#define CMD_STATUS 0x0014
> > +
> > +/* Interrupt status register. */
> > +#define INTR_STATUS 0x0110
> > +#define INTR_STATUS_SDMA_ERR BIT(22)
> > +#define INTR_STATUS_SDMA_TRIGG BIT(21)
> > +#define INTR_STATUS_UNSUPP_CMD BIT(19)
> > +#define INTR_STATUS_DDMA_TERR BIT(18)
> > +#define INTR_STATUS_CDMA_TERR BIT(17)
> > +#define INTR_STATUS_CDMA_IDL BIT(16)
> > +
> > +/* Interrupt enable register. */
> > +#define INTR_ENABLE 0x0114
> > +#define INTR_ENABLE_INTR_EN BIT(31)
> > +#define INTR_ENABLE_SDMA_ERR_EN BIT(22)
> > +#define INTR_ENABLE_SDMA_TRIGG_EN BIT(21)
> > +#define INTR_ENABLE_UNSUPP_CMD_EN BIT(19)
> > +#define INTR_ENABLE_DDMA_TERR_EN BIT(18)
> > +#define INTR_ENABLE_CDMA_TERR_EN BIT(17)
> > +#define INTR_ENABLE_CDMA_IDLE_EN BIT(16)
> > +
> > +/* Controller internal state. */
> > +#define CTRL_STATUS 0x0118
> > +#define CTRL_STATUS_INIT_COMP BIT(9)
> > +#define CTRL_STATUS_CTRL_BUSY BIT(8)
> > +
> > +/* Command Engine threads state. */
> > +#define TRD_STATUS 0x0120
> > +
> > +/* Command Engine interrupt thread error status. */
> > +#define TRD_ERR_INT_STATUS 0x0128
> > +/* Command Engine interrupt thread error enable. */
> > +#define TRD_ERR_INT_STATUS_EN 0x0130
> > +/* Command Engine interrupt thread complete status. */
> > +#define TRD_COMP_INT_STATUS 0x0138
> > +
> > +/*
> > + * Transfer config 0 register.
> > + * Configures data transfer parameters.
> > + */
> > +#define TRAN_CFG_0 0x0400
> > +/* Offset value from the beginning of the page. */
> > +#define TRAN_CFG_0_OFFSET GENMASK(31, 16)
> > +/* Numbers of sectors to transfer within singlNF device's page. */
> > +#define TRAN_CFG_0_SEC_CNT GENMASK(7, 0)
> > +
> > +/*
> > + * Transfer config 1 register.
> > + * Configures data transfer parameters.
> > + */
> > +#define TRAN_CFG_1 0x0404
> > +/* Size of last data sector. */
> > +#define TRAN_CFG_1_LAST_SEC_SIZE GENMASK(31, 16)
> > +/* Size of not-last data sector. */
> > +#define TRAN_CFG_1_SECTOR_SIZE GENMASK(15, 0)
> > +
> > +/* ECC engine configuration register 0. */
> > +#define ECC_CONFIG_0 0x0428
> > +/* Correction strength. */
> > +#define ECC_CONFIG_0_CORR_STR GENMASK(10, 8)
> > +/* Enable erased pages detection mechanism. */
> > +#define ECC_CONFIG_0_ERASE_DET_EN BIT(1)
> > +/* Enable controller ECC check bits generation and correction. */
> > +#define ECC_CONFIG_0_ECC_EN BIT(0)
> > +
> > +/* ECC engine configuration register 1. */
> > +#define ECC_CONFIG_1 0x042C
> > +
> > +/* Multiplane settings register. */
> > +#define MULTIPLANE_CFG 0x0434
> > +/* Cache operation settings. */
> > +#define CACHE_CFG 0x0438
> > +
> > +/* DMA settings register. */
> > +#define DMA_SETINGS 0x043C
> > +/* Enable SDMA error report on access unprepared slave DMA interface. */
> > +#define DMA_SETINGS_SDMA_ERR_RSP BIT(17)
> > +
> > +/* Transferred data block size for the slave DMA module. */
> > +#define SDMA_SIZE 0x0440
> > +
> > +/* Thread number associated with transferred data block
> > + * for the slave DMA module.
> > + */
> > +#define SDMA_TRD_NUM 0x0444
> > +/* Thread number mask. */
> > +#define SDMA_TRD_NUM_SDMA_TRD GENMASK(2, 0)
> > +
> > +#define CONTROL_DATA_CTRL 0x0494
> > +/* Thread number mask. */
> > +#define CONTROL_DATA_CTRL_SIZE GENMASK(15, 0)
> > +
> > +#define CTRL_VERSION 0x800
> > +
> > +/* Available hardware features of the controller. */
> > +#define CTRL_FEATURES 0x804
> > +/* Support for NV-DDR2/3 work mode. */
> > +#define CTRL_FEATURES_NVDDR_2_3 BIT(28)
> > +/* Support for NV-DDR work mode. */
> > +#define CTRL_FEATURES_NVDDR BIT(27)
> > +/* Support for asynchronous work mode. */
> > +#define CTRL_FEATURES_ASYNC BIT(26)
> > +/* Support for asynchronous work mode. */
> > +#define CTRL_FEATURES_N_BANKS GENMASK(25, 24)
> > +/* Slave and Master DMA data width. */
> > +#define CTRL_FEATURES_DMA_DWITH64 BIT(21)
> > +/* Availability of Control Data feature.*/
> > +#define CTRL_FEATURES_CONTROL_DATA BIT(10)
> > +
> > +/* BCH Engine identification register 0 - correction strengths. */
> > +#define BCH_CFG_0 0x838
> > +#define BCH_CFG_0_CORR_CAP_0 GENMASK(7, 0)
> > +#define BCH_CFG_0_CORR_CAP_1 GENMASK(15, 8)
> > +#define BCH_CFG_0_CORR_CAP_2 GENMASK(23, 16)
> > +#define BCH_CFG_0_CORR_CAP_3 GENMASK(31, 24)
> > +
> > +/* BCH Engine identification register 1 - correction strengths. */
> > +#define BCH_CFG_1 0x83C
> > +#define BCH_CFG_1_CORR_CAP_4 GENMASK(7, 0)
> > +#define BCH_CFG_1_CORR_CAP_5 GENMASK(15, 8)
> > +#define BCH_CFG_1_CORR_CAP_6 GENMASK(23, 16)
> > +#define BCH_CFG_1_CORR_CAP_7 GENMASK(31, 24)
> > +
> > +/* BCH Engine identification register 2 - sector sizes. */
> > +#define BCH_CFG_2 0x840
> > +#define BCH_CFG_2_SECT_0 GENMASK(15, 0)
> > +#define BCH_CFG_2_SECT_1 GENMASK(31, 16)
> > +
> > +/* BCH Engine identification register 3. */
> > +#define BCH_CFG_3 0x844
> > +
> > +/* Ready/Busy# line status. */
> > +#define RBN_SETINGS 0x1004
> > +
> > +/* Common settings. */
> > +#define COMMON_SET 0x1008
> > +/* 16 bit device connected to the NAND Flash interface. */
> > +#define COMMON_SET_DEVICE_16BIT BIT(8)
> > +
> > +/* Skip_bytes registers. */
> > +#define SKIP_BYTES_CONF 0x100C
> > +#define SKIP_BYTES_MARKER_VALUE GENMASK(31, 16)
> > +#define SKIP_BYTES_NUM_OF_BYTES GENMASK(7, 0)
> > +
> > +#define SKIP_BYTES_OFFSET 0x1010
> > +#define SKIP_BYTES_OFFSET_VALUE GENMASK(23, 0)
> > +
> > +/* Timings configuration. */
> > +#define ASYNC_TOGGLE_TIMINGS 0x101c
> > +#define ASYNC_TOGGLE_TIMINGS_TRH GENMASK(28, 24)
> > +#define ASYNC_TOGGLE_TIMINGS_TRP GENMASK(20, 16)
> > +#define ASYNC_TOGGLE_TIMINGS_TWH GENMASK(12, 8)
> > +#define ASYNC_TOGGLE_TIMINGS_TWP GENMASK(4, 0)
> > +
> > +#define TIMINGS0 0x1024
> > +#define TIMINGS0_TADL GENMASK(31, 24)
> > +#define TIMINGS0_TCCS GENMASK(23, 16)
> > +#define TIMINGS0_TWHR GENMASK(15, 8)
> > +#define TIMINGS0_TRHW GENMASK(7, 0)
> > +
> > +#define TIMINGS1 0x1028
> > +#define TIMINGS1_TRHZ GENMASK(31, 24)
> > +#define TIMINGS1_TWB GENMASK(23, 16)
> > +#define TIMINGS1_TVDLY GENMASK(7, 0)
> > +
> > +#define TIMINGS2 0x102c
> > +#define TIMINGS2_TFEAT GENMASK(25, 16)
> > +#define TIMINGS2_CS_HOLD_TIME GENMASK(13, 8)
> > +#define TIMINGS2_CS_SETUP_TIME GENMASK(5, 0)
> > +
> > +/* Configuration of the resynchronization of slave DLL of PHY. */
> > +#define DLL_PHY_CTRL 0x1034
> > +#define DLL_PHY_CTRL_DLL_RST_N BIT(24)
> > +#define DLL_PHY_CTRL_EXTENDED_WR_MODE BIT(17)
> > +#define DLL_PHY_CTRL_EXTENDED_RD_MODE BIT(16)
> > +#define DLL_PHY_CTRL_RS_HIGH_WAIT_CNT GENMASK(11, 8)
> > +#define DLL_PHY_CTRL_RS_IDLE_CNT GENMASK(7, 0)
> > +
> > +/* Register controlling DQ related timing. */
> > +#define PHY_DQ_TIMING 0x2000
> > +/* Register controlling DSQ related timing. */
> > +#define PHY_DQS_TIMING 0x2004
> > +#define PHY_DQS_TIMING_DQS_SEL_OE_END GENMASK(3, 0)
> > +#define PHY_DQS_TIMING_PHONY_DQS_SEL BIT(16)
> > +#define PHY_DQS_TIMING_USE_PHONY_DQS BIT(20)
> > +
> > +/* Register controlling the gate and loopback control related timing. */
> > +#define PHY_GATE_LPBK_CTRL 0x2008
> > +#define PHY_GATE_LPBK_CTRL_RDS GENMASK(24, 19)
> > +
> > +/* Register holds the control for the master DLL logic. */
> > +#define PHY_DLL_MASTER_CTRL 0x200C
> > +#define PHY_DLL_MASTER_CTRL_BYPASS_MODE BIT(23)
> > +
> > +/* Register holds the control for the slave DLL logic. */
> > +#define PHY_DLL_SLAVE_CTRL 0x2010
> > +
> > +/* This register handles the global control settings for the PHY. */
> > +#define PHY_CTRL 0x2080
> > +#define PHY_CTRL_SDR_DQS BIT(14)
> > +#define PHY_CTRL_PHONY_DQS GENMASK(9, 4)
> > +
> > +/*
> > + * This register handles the global control settings
> > + * for the termination selects for reads.
> > + */
> > +#define PHY_TSEL 0x2084
> > +
> > +/* Generic command layout. */
> > +#define GCMD_LAY_CS GENMASK_ULL(11, 8)
> > +/*
> > + * This bit informs the minicotroller if it has to wait for tWB
> > + * after sending the last CMD/ADDR/DATA in the sequence.
> > + */
> > +#define GCMD_LAY_TWB BIT_ULL(6)
> > +/* Type of generic instruction. */
> > +#define GCMD_LAY_INSTR GENMASK_ULL(5, 0)
> > +
> > +/* Generic CMD sequence type. */
> > +#define GCMD_LAY_INSTR_CMD 0
> > +/* Generic ADDR sequence type. */
> > +#define GCMD_LAY_INSTR_ADDR 1
> > +/* Generic data transfer sequence type. */
> > +#define GCMD_LAY_INSTR_DATA 2
> > +
> > +/* Input part of generic command type of input is command. */
> > +#define GCMD_LAY_INPUT_CMD GENMASK_ULL(23, 16)
> > +
> > +/* Generic command address sequence - address fields. */
> > +#define GCMD_LAY_INPUT_ADDR GENMASK_ULL(63, 16)
> > +/* Generic command address sequence - address size. */
> > +#define GCMD_LAY_INPUT_ADDR_SIZE GENMASK_ULL(13, 11)
> > +
> > +/* Transfer direction field of generic command data sequence. */
> > +#define GCMD_DIR BIT_ULL(11)
> > +/* Read transfer direction of generic command data sequence. */
> > +#define GCMD_DIR_READ 0
> > +/* Write transfer direction of generic command data sequence. */
> > +#define GCMD_DIR_WRITE 1
> > +
> > +/* ECC enabled flag of generic command data sequence - ECC enabled. */
> > +#define GCMD_ECC_EN BIT_ULL(12)
> > +/* Generic command data sequence - sector size. */
> > +#define GCMD_SECT_SIZE GENMASK_ULL(31, 16)
> > +/* Generic command data sequence - sector count. */
> > +#define GCMD_SECT_CNT GENMASK_ULL(39, 32)
> > +/* Generic command data sequence - last sector size. */
> > +#define GCMD_LAST_SIZE GENMASK_ULL(55, 40)
> > +
> > +/* CDMA descriptor fields. */
> > +/* Erase command type of CDMA descriptor. */
> > +#define CDMA_CT_ERASE 0x1000
> > +/* Program page command type of CDMA descriptor. */
> > +#define CDMA_CT_WR 0x2100
> > +/* Read page command type of CDMA descriptor. */
> > +#define CDMA_CT_RD 0x2200
> > +
> > +/* Flash pointer memory shift. */
> > +#define CDMA_CFPTR_MEM_SHIFT 24
> > +/* Flash pointer memory mask. */
> > +#define CDMA_CFPTR_MEM GENMASK(26, 24)
> > +
> > +/*
> > + * Command DMA descriptor flags. If set causes issue interrupt after
> > + * the completion of descriptor processing.
> > + */
> > +#define CDMA_CF_INT BIT(8)
> > +/*
> > + * Command DMA descriptor flags - the next descriptor
> > + * address field is valid and descriptor processing should continue.
> > + */
> > +#define CDMA_CF_CONT BIT(9)
> > +/* DMA master flag of command DMA descriptor. */
> > +#define CDMA_CF_DMA_MASTER BIT(10)
> > +
> > +/* Operation complete status of command descriptor. */
> > +#define CDMA_CS_COMP BIT(15)
> > +/* Operation complete status of command descriptor. */
> > +/* Command descriptor status - operation fail. */
> > +#define CDMA_CS_FAIL BIT(14)
> > +/* Command descriptor status - page erased. */
> > +#define CDMA_CS_ERP BIT(11)
> > +/* Command descriptor status - timeout occurred. */
> > +#define CDMA_CS_TOUT BIT(10)
> > +/*
> > + * Maximum amount of correction applied to one ECC sector.
> > + * It is part of command descriptor status.
> > + */
> > +#define CDMA_CS_MAXERR GENMASK(9, 2)
> > +/* Command descriptor status - uncorrectable ECC error. */
> > +#define CDMA_CS_UNCE BIT(1)
> > +/* Command descriptor status - descriptor error. */
> > +#define CDMA_CS_ERR BIT(0)
> > +
> > +/* Status of operation - OK. */
> > +#define STAT_OK 0
> > +/* Status of operation - FAIL. */
> > +#define STAT_FAIL 2
> > +/* Status of operation - uncorrectable ECC error. */
> > +#define STAT_ECC_UNCORR 3
> > +/* Status of operation - page erased. */
> > +#define STAT_ERASED 5
> > +/* Status of operation - correctable ECC error. */
> > +#define STAT_ECC_CORR 6
> > +/* Status of operation - unsuspected state. */
> > +#define STAT_UNKNOWN 7
> > +/* Status of operation - operation is not completed yet. */
> > +#define STAT_BUSY 0xFF
> > +
> > +#define BCH_MAX_NUM_CORR_CAPS 8
> > +#define BCH_MAX_NUM_SECTOR_SIZES 2
> > +
> > +struct cadence_nand_timings {
> > + u32 async_toggle_timings;
> > + u32 timings0;
> > + u32 timings1;
> > + u32 timings2;
> > + u32 dll_phy_ctrl;
> > + u32 phy_ctrl;
> > + u32 phy_dqs_timing;
> > + u32 phy_gate_lpbk_ctrl;
> > +};
> > +
> > +/* Command DMA descriptor. */
> > +struct cadence_nand_cdma_desc {
> > + /* Next descriptor address. */
> > + u64 next_pointer;
> > +
> > + /* Flash address is a 32-bit address comprising of BANK and ROW ADDR. */
> > + u32 flash_pointer;
> > + u32 rsvd0;
> > +
> > + /* Operation the controller needs to perform. */
> > + u16 command_type;
> > + u16 rsvd1;
> > + /* Flags for operation of this command. */
> > + u16 command_flags;
> > + u16 rsvd2;
> > +
> > + /* System/host memory address required for data DMA commands. */
> > + u64 memory_pointer;
> > +
> > + /* Status of operation. */
> > + u32 status;
> > + u32 rsvd3;
> > +
> > + /* Address pointer to sync buffer location. */
> > + u64 sync_flag_pointer;
> > +
> > + /* Controls the buffer sync mechanism. */
> > + u32 sync_arguments;
> > + u32 rsvd4;
> > +
> > + /* Control data pointer. */
> > + u64 ctrl_data_ptr;
> > +};
> > +
> > +/* Interrupt status. */
> > +struct cadence_nand_irq_status {
> > + /* Thread operation complete status. */
> > + u32 trd_status;
> > + /* Thread operation error. */
> > + u32 trd_error;
> > + /* Controller status. */
> > + u32 status;
> > +};
> > +
> > +/* Cadence NAND flash controller capabilities get from driver data. */
> > +struct cadence_nand_dt_devdata {
> > + /* Skew value of the output signals of the NAND Flash interface. */
> > + u32 if_skew;
> > + /* It informs if slave DMA interface is connected to DMA engine. */
> > + unsigned int has_dma:1;
> > +};
> > +
> > +/* Cadence NAND flash controller capabilities read from registers. */
> > +struct cdns_nand_caps {
> > + /* Maximum number of banks supported by hardware. */
> > + u8 max_banks;
> > + /* Slave and Master DMA data width in bytes (4 or 8). */
> > + u8 data_dma_width;
> > + /* Control Data feature supported. */
> > + u8 data_control_supp;
> > + /* Is PHY type DLL. */
> > + u8 is_phy_type_dll;
>
> I'd make 'data_control_supp' and 'is_phy_type_dll' u8:1 or unsigned
> int:1 as you did for 'has_dma', for consistency.

Or just booleans. I know under certain circumstances it can be badly
handled but I don't think we care here.


Thanks,
MiquÃl