lkml.org 
[lkml]   [2018]   [Sep]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 2/3] mtd: rawnand: stm32_fmc2: add STM32 FMC2 NAND flash controller driver
From
Date
Hi Miquèl,

On 09/22/2018 03:48 PM, Miquel Raynal wrote:
> Hi Christophe,
>
> I suppose you received the kbuildrobot issues already, please have a
> look at them.

Yes, kbuidroot issues will be solved in the v2 patchset.

>
> The driver looks well, some comments below.
>
> <christophe.kerello@st.com> wrote on Mon, 17 Sep 2018 17:47:39 +0200:
>
>> From: Christophe Kerello <christophe.kerello@st.com>
>>
>> The driver adds the support for the STMicroelectronics FMC2 NAND
>> Controller found on STM32MP SOCs.
>>
>> This patch is based on FMC2 command sequencer.
>> The purpose of the command sequencer is to facilitate the programming
>> and the reading of NAND flash pages with the ECC and to free the CPU
>> of sequencing tasks.
>> It requires one DMA channel for write and two DMA channels for read
>> operations.
>>
>> Only NAND_ECC_HW mode is actually supported.
>> The driver supports a maximum 8k page size.
>> The following ECC strength and step size are currently supported:
>> - nand-ecc-strength = <8>, nand-ecc-step-size = <512> (BCH8)
>> - nand-ecc-strength = <4>, nand-ecc-step-size = <512> (BCH4)
>> - nand-ecc-strength = <1>, nand-ecc-step-size = <512> (Extended ecc
>> based on HAMMING)
>>
>> This patch has been tested on Micron MT29F8G08ABACAH4 and
>> MT29F8G16ABACAH4
>>
>> Signed-off-by: Christophe Kerello <christophe.kerello@st.com>
>> ---
>> drivers/mtd/nand/raw/Kconfig | 9 +
>> drivers/mtd/nand/raw/Makefile | 1 +
>> drivers/mtd/nand/raw/stm32_fmc2_nand.c | 1729 ++++++++++++++++++++++++++++++++
>> 3 files changed, 1739 insertions(+)
>> create mode 100644 drivers/mtd/nand/raw/stm32_fmc2_nand.c
>>
>> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
>> index c7efc31..863662c 100644
>> --- a/drivers/mtd/nand/raw/Kconfig
>> +++ b/drivers/mtd/nand/raw/Kconfig
>> @@ -541,4 +541,13 @@ config MTD_NAND_TEGRA
>> is supported. Extra OOB bytes when using HW ECC are currently
>> not supported.
>>
>> +config MTD_NAND_STM32_FMC2
>> + tristate "Support for NAND controller on STM32MP SoCs"
>> + depends on MACH_STM32MP157 || COMPILE_TEST
>> + help
>> + Enables support for NAND Flash chips on SoCs containing the FMC2
>> + NAND controller. This controller is found on STM32MP SoCs.
>> + The driver supports a maximum 8k page size. HW ECC is enabled and
>> + supports a maximum 8-bit correction error per sector of 512 bytes.
>
> HW ECC should not be enabled by default. 8-bit/512B of correctability
> is good but not that high and people might want to use software ECC in
> conjunction with raw accesses.

Yes, I agree. The driver only supports NAND_ECC_HW mode. NAND_ECC_SOFT
mode was not requested by customers and was not implemented. The driver
could be improved later to support mode like NAND_ECC_SOFT or
NAND_ECC_ON_DIE. Should I remove "HW ECC is enabled" from Kconfig
description?

>
>> +
>> endif # MTD_NAND
>> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
>> index a6ef067..8c437e3 100644
>> --- a/drivers/mtd/nand/raw/Makefile
>> +++ b/drivers/mtd/nand/raw/Makefile
>> @@ -56,6 +56,7 @@ 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_TEGRA) += tegra_nand.o
>> +obj-$(CONFIG_MTD_NAND_STM32_FMC2) += stm32_fmc2_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/stm32_fmc2_nand.c b/drivers/mtd/nand/raw/stm32_fmc2_nand.c
>> new file mode 100644
>> index 0000000..dd5762a
>> --- /dev/null
>> +++ b/drivers/mtd/nand/raw/stm32_fmc2_nand.c
>> @@ -0,0 +1,1729 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
>> + * Author: Christophe Kerello <christophe.kerello@st.com> for STMicroelectronics
>
> I'm not sure the "All rights reserved" has a meaning here.
>
> But you definitely not have to add "for STMicroelectronics" because it
> is already in the copyright.

Ok.

>
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/dmaengine.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/errno.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/iopoll.h>
>> +#include <linux/module.h>
>> +#include <linux/mtd/rawnand.h>
>> +#include <linux/pinctrl/consumer.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/reset.h>
>> +
>> +/* Bad block marker length */
>> +#define FMC2_BBM_LEN 2
>> +
>> +/* ECC step size */
>> +#define FMC2_ECC_STEP_SIZE 512
>> +
>> +/* BCHDSRx registers length */
>> +#define FMC2_BCHDSRS_LEN 20
>> +
>> +/* HECCR length */
>> +#define FMC2_HECCR_LEN 4
>> +
>> +/* Max requests done for a 8k nand page size */
>> +#define FMC2_MAX_SG_COUNT 16
>> +
>> +/* Max chip enable */
>> +#define FMC2_MAX_CE 2
>> +
>> +/* Timings */
>> +#define FMC2_THIZ 1
>> +#define FMC2_TIO 8000
>> +#define FMC2_TSYNC 3000
>> +#define FMC2_PCR_TIMING_MASK 0xf
>> +#define FMC2_PMEM_PATT_TIMING_MASK 0xff
>> +
>> +/* FMC2 Controller Registers */
>> +#define FMC2_BCR1 0x0
>> +#define FMC2_PCR 0x80
>> +#define FMC2_SR 0x84
>> +#define FMC2_PMEM 0x88
>> +#define FMC2_PATT 0x8c
>> +#define FMC2_HECCR 0x94
>> +#define FMC2_CSQCR 0x200
>> +#define FMC2_CSQCFGR1 0x204
>> +#define FMC2_CSQCFGR2 0x208
>> +#define FMC2_CSQCFGR3 0x20c
>> +#define FMC2_CSQAR1 0x210
>> +#define FMC2_CSQAR2 0x214
>> +#define FMC2_CSQIER 0x220
>> +#define FMC2_CSQISR 0x224
>> +#define FMC2_CSQICR 0x228
>> +#define FMC2_CSQEMSR 0x230
>> +#define FMC2_BCHIER 0x250
>> +#define FMC2_BCHISR 0x254
>> +#define FMC2_BCHICR 0x258
>> +#define FMC2_BCHPBR1 0x260
>> +#define FMC2_BCHPBR2 0x264
>> +#define FMC2_BCHPBR3 0x268
>> +#define FMC2_BCHPBR4 0x26c
>> +#define FMC2_BCHDSR0 0x27c
>> +#define FMC2_BCHDSR1 0x280
>> +#define FMC2_BCHDSR2 0x284
>> +#define FMC2_BCHDSR3 0x288
>> +#define FMC2_BCHDSR4 0x28c
>> +
>> +/* Register: FMC2_BCR1 */
>> +#define FMC2_BCR1_FMC2EN BIT(31)
>> +
>> +/* Register: FMC2_PCR */
>> +#define FMC2_PCR_PWAITEN BIT(1)
>> +#define FMC2_PCR_PBKEN BIT(2)
>> +#define FMC2_PCR_PWID_MASK GENMASK(5, 4)
>> +#define FMC2_PCR_PWID(x) (((x) & 0x3) << 4)
>> +#define FMC2_PCR_PWID_BUSWIDTH_8 0
>> +#define FMC2_PCR_PWID_BUSWIDTH_16 1
>> +#define FMC2_PCR_ECCEN BIT(6)
>> +#define FMC2_PCR_ECCALG BIT(8)
>> +#define FMC2_PCR_TCLR_MASK GENMASK(12, 9)
>> +#define FMC2_PCR_TCLR(x) (((x) & 0xf) << 9)
>> +#define FMC2_PCR_TCLR_DEFAULT 0xf
>> +#define FMC2_PCR_TAR_MASK GENMASK(16, 13)
>> +#define FMC2_PCR_TAR(x) (((x) & 0xf) << 13)
>> +#define FMC2_PCR_TAR_DEFAULT 0xf
>> +#define FMC2_PCR_ECCSS_MASK GENMASK(19, 17)
>> +#define FMC2_PCR_ECCSS(x) (((x) & 0x7) << 17)
>> +#define FMC2_PCR_ECCSS_512 1
>> +#define FMC2_PCR_ECCSS_2048 3
>> +#define FMC2_PCR_BCHECC BIT(24)
>> +#define FMC2_PCR_WEN BIT(25)
>> +
>> +/* Register: FMC2_SR */
>> +#define FMC2_SR_NWRF BIT(6)
>> +
>> +/* Register: FMC2_PMEM */
>> +#define FMC2_PMEM_MEMSET(x) (((x) & 0xff) << 0)
>> +#define FMC2_PMEM_MEMWAIT(x) (((x) & 0xff) << 8)
>> +#define FMC2_PMEM_MEMHOLD(x) (((x) & 0xff) << 16)
>> +#define FMC2_PMEM_MEMHIZ(x) (((x) & 0xff) << 24)
>> +#define FMC2_PMEM_DEFAULT 0x0a0a0a0a
>> +
>> +/* Register: FMC2_PATT */
>> +#define FMC2_PATT_ATTSET(x) (((x) & 0xff) << 0)
>> +#define FMC2_PATT_ATTWAIT(x) (((x) & 0xff) << 8)
>> +#define FMC2_PATT_ATTHOLD(x) (((x) & 0xff) << 16)
>> +#define FMC2_PATT_ATTHIZ(x) (((x) & 0xff) << 24)
>> +#define FMC2_PATT_DEFAULT 0x0a0a0a0a
>> +
>> +/* Register: FMC2_CSQCR */
>> +#define FMC2_CSQCR_CSQSTART BIT(0)
>> +
>> +/* Register: FMC2_CSQCFGR1 */
>> +#define FMC2_CSQCFGR1_CMD2EN BIT(1)
>> +#define FMC2_CSQCFGR1_DMADEN BIT(2)
>> +#define FMC2_CSQCFGR1_ACYNBR(x) (((x) & 0x7) << 4)
>> +#define FMC2_CSQCFGR1_CMD1(x) (((x) & 0xff) << 8)
>> +#define FMC2_CSQCFGR1_CMD2(x) (((x) & 0xff) << 16)
>> +#define FMC2_CSQCFGR1_CMD1T BIT(24)
>> +#define FMC2_CSQCFGR1_CMD2T BIT(25)
>> +
>> +/* Register: FMC2_CSQCFGR2 */
>> +#define FMC2_CSQCFGR2_SQSDTEN BIT(0)
>> +#define FMC2_CSQCFGR2_RCMD2EN BIT(1)
>> +#define FMC2_CSQCFGR2_DMASEN BIT(2)
>> +#define FMC2_CSQCFGR2_RCMD1(x) (((x) & 0xff) << 8)
>> +#define FMC2_CSQCFGR2_RCMD2(x) (((x) & 0xff) << 16)
>> +#define FMC2_CSQCFGR2_RCMD1T BIT(24)
>> +#define FMC2_CSQCFGR2_RCMD2T BIT(25)
>> +
>> +/* Register: FMC2_CSQCFGR3 */
>> +#define FMC2_CSQCFGR3_SNBR(x) (((x) & 0x1f) << 8)
>> +#define FMC2_CSQCFGR3_AC1T BIT(16)
>> +#define FMC2_CSQCFGR3_AC2T BIT(17)
>> +#define FMC2_CSQCFGR3_AC3T BIT(18)
>> +#define FMC2_CSQCFGR3_AC4T BIT(19)
>> +#define FMC2_CSQCFGR3_AC5T BIT(20)
>> +#define FMC2_CSQCFGR3_SDT BIT(21)
>> +#define FMC2_CSQCFGR3_RAC1T BIT(22)
>> +#define FMC2_CSQCFGR3_RAC2T BIT(23)
>> +
>> +/* Register: FMC2_CSQCAR1 */
>> +#define FMC2_CSQCAR1_ADDC1(x) (((x) & 0xff) << 0)
>> +#define FMC2_CSQCAR1_ADDC2(x) (((x) & 0xff) << 8)
>> +#define FMC2_CSQCAR1_ADDC3(x) (((x) & 0xff) << 16)
>> +#define FMC2_CSQCAR1_ADDC4(x) (((x) & 0xff) << 24)
>> +
>> +/* Register: FMC2_CSQCAR2 */
>> +#define FMC2_CSQCAR2_ADDC5(x) (((x) & 0xff) << 0)
>> +#define FMC2_CSQCAR2_NANDCEN(x) (((x) & 0x3) << 10)
>> +#define FMC2_CSQCAR2_SAO(x) (((x) & 0xffff) << 16)
>> +
>> +/* Register: FMC2_CSQIER */
>> +#define FMC2_CSQIER_TCIE BIT(0)
>> +
>> +/* Register: FMC2_CSQICR */
>> +#define FMC2_CSQICR_CLEAR_IRQ GENMASK(4, 0)
>> +
>> +/* Register: FMC2_CSQEMSR */
>> +#define FMC2_CSQEMSR_SEM GENMASK(15, 0)
>> +
>> +/* Register: FMC2_BCHIER */
>> +#define FMC2_BCHIER_DERIE BIT(1)
>> +#define FMC2_BCHIER_EPBRIE BIT(4)
>> +
>> +/* Register: FMC2_BCHICR */
>> +#define FMC2_BCHICR_CLEAR_IRQ GENMASK(4, 0)
>> +
>> +/* Register: FMC2_BCHDSR0 */
>> +#define FMC2_BCHDSR0_DUE BIT(0)
>> +#define FMC2_BCHDSR0_DEF BIT(1)
>> +#define FMC2_BCHDSR0_DEN_MASK GENMASK(7, 4)
>> +#define FMC2_BCHDSR0_DEN_SHIFT 4
>> +
>> +/* Register: FMC2_BCHDSR1 */
>> +#define FMC2_BCHDSR1_EBP1_MASK GENMASK(12, 0)
>> +#define FMC2_BCHDSR1_EBP2_MASK GENMASK(28, 16)
>> +#define FMC2_BCHDSR1_EBP2_SHIFT 16
>> +
>> +/* Register: FMC2_BCHDSR2 */
>> +#define FMC2_BCHDSR2_EBP3_MASK GENMASK(12, 0)
>> +#define FMC2_BCHDSR2_EBP4_MASK GENMASK(28, 16)
>> +#define FMC2_BCHDSR2_EBP4_SHIFT 16
>> +
>> +/* Register: FMC2_BCHDSR3 */
>> +#define FMC2_BCHDSR3_EBP5_MASK GENMASK(12, 0)
>> +#define FMC2_BCHDSR3_EBP6_MASK GENMASK(28, 16)
>> +#define FMC2_BCHDSR3_EBP6_SHIFT 16
>> +
>> +/* Register: FMC2_BCHDSR4 */
>> +#define FMC2_BCHDSR4_EBP7_MASK GENMASK(12, 0)
>> +#define FMC2_BCHDSR4_EBP8_MASK GENMASK(28, 16)
>> +#define FMC2_BCHDSR4_EBP8_SHIFT 16
>> +
>> +enum stm32_fmc2_ecc {
>> + FMC2_ECC_HAM = 1,
>> + FMC2_ECC_BCH4 = 4,
>> + FMC2_ECC_BCH8 = 8
>> +};
>> +
>> +struct stm32_fmc2_timings {
>> + u8 tclr;
>> + u8 tar;
>> + u8 thiz;
>> + u8 twait;
>> + u8 thold_mem;
>> + u8 tset_mem;
>> + u8 thold_att;
>> + u8 tset_att;
>> +};
>> +
>> +struct stm32_fmc2 {
>> + struct nand_chip chip;
>> + struct device *dev;
>> + void __iomem *io_base;
>> + void __iomem *data_base[FMC2_MAX_CE];
>> + void __iomem *cmd_base[FMC2_MAX_CE];
>> + void __iomem *addr_base[FMC2_MAX_CE];
>> + phys_addr_t io_phys_addr;
>> + phys_addr_t data_phys_addr[FMC2_MAX_CE];
>> + struct clk *clk;
>> +
>> + struct dma_chan *dma_tx_ch;
>> + struct dma_chan *dma_rx_ch;
>> + struct dma_chan *dma_ecc_ch;
>> + struct sg_table dma_data_sg;
>> + struct sg_table dma_ecc_sg;
>> + u8 *ecc_buf;
>> + int dma_ecc_len;
>> +
>> + struct completion complete;
>> + struct completion dma_data_complete;
>> + struct completion dma_ecc_complete;
>> +
>> + struct stm32_fmc2_timings timings;
>> + u8 cs_assigned;
>> + int cs_sel;
>> + int ncs;
>> + int cs_used[FMC2_MAX_CE];
>> +};
>> +
>> +/* Enable irq sources in case of the sequencer is used */
>> +static inline void stm32_fmc2_enable_seq_irq(struct stm32_fmc2 *fmc2)
>> +{
>> + u32 csqier = readl_relaxed(fmc2->io_base + FMC2_CSQIER);
>> +
>> + csqier |= FMC2_CSQIER_TCIE;
>> +
>> + writel_relaxed(csqier, fmc2->io_base + FMC2_CSQIER);
>> +}
>> +
>> +/* Disable irq sources in case of the sequencer is used */
>> +static inline void stm32_fmc2_disable_seq_irq(struct stm32_fmc2 *fmc2)
>> +{
>> + u32 csqier = readl_relaxed(fmc2->io_base + FMC2_CSQIER);
>> +
>> + csqier &= ~FMC2_CSQIER_TCIE;
>> +
>> + writel_relaxed(csqier, fmc2->io_base + FMC2_CSQIER);
>> +}
>> +
>> +/* Clear irq sources in case of the sequencer is used */
>> +static inline void stm32_fmc2_clear_seq_irq(struct stm32_fmc2 *fmc2)
>> +{
>> + writel_relaxed(FMC2_CSQICR_CLEAR_IRQ, fmc2->io_base + FMC2_CSQICR);
>> +}
>> +
>> +/* Select function */
>> +static void stm32_fmc2_select_chip(struct nand_chip *chip, int chipnr)
>> +{
>> + struct stm32_fmc2 *fmc2 = nand_get_controller_data(chip);
>> + struct dma_slave_config dma_cfg;
>> +
>> + if (chipnr < 0 || chipnr >= fmc2->ncs)
>> + return;
>> +
>> + if (fmc2->cs_used[chipnr] == fmc2->cs_sel)
>> + return;
>> +
>> + fmc2->cs_sel = fmc2->cs_used[chipnr];
>> +
>> + if (fmc2->dma_tx_ch && fmc2->dma_rx_ch) {
>> + memset(&dma_cfg, 0, sizeof(dma_cfg));
>> + dma_cfg.src_addr = fmc2->data_phys_addr[fmc2->cs_sel];
>> + dma_cfg.dst_addr = fmc2->data_phys_addr[fmc2->cs_sel];
>> + dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>> + dma_cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>> + dma_cfg.src_maxburst = 32;
>> + dma_cfg.dst_maxburst = 32;
>> +
>> + if (dmaengine_slave_config(fmc2->dma_tx_ch, &dma_cfg))
>> + dev_warn(fmc2->dev, "tx DMA engine slave config failed\n");
>> +
>> + if (dmaengine_slave_config(fmc2->dma_rx_ch, &dma_cfg))
>> + dev_warn(fmc2->dev, "rx DMA engine slave config failed\n");
>> + }
>
> What if there are two NAND chips using different timing modes? You
> should probably reconfigure the timings registers, unless there are
> already a set of timing registers per CS?

Yes, it's true. In case of 2 NAND chips, timings and pcr registers
should have been reconfigured. But, the driver only supports one NAND
chip connected to 1 or 2 CS. There was no requirement on our side to
support 2 different NAND chips. I do not have a board to test such
configuration, so i do not want to deliver this support without being
able to test it on my side. The driver will be improved later to support
2 different NAND chips, in case this configuration is requested by
customers.

>> +}
>> +
>> +/*
>> + * ECC HAMMING calculation
>> + * ECC is 3 bytes for 512 bytes of data (supports error correction up to
>> + * max of 1-bit)
>> + */
>> +static inline void stm32_fmc2_ham_set_ecc(const u32 ecc_sta, u8 *ecc)
>> +{
>> + ecc[0] = ecc_sta;
>> + ecc[1] = ecc_sta >> 8;
>> + ecc[2] = ecc_sta >> 16;
>> +}
>> +
>> +static int stm32_fmc2_ham_correct(struct nand_chip *chip, uint8_t *dat,
>> + uint8_t *read_ecc, uint8_t *calc_ecc)
>> +{
>> + u8 bit_position = 0, b0, b1, b2;
>> + u32 byte_addr = 0, b;
>> + u32 i, shifting = 1;
>> +
>> + /* Indicate which bit and byte is faulty (if any) */
>> + b0 = read_ecc[0] ^ calc_ecc[0];
>> + b1 = read_ecc[1] ^ calc_ecc[1];
>> + b2 = read_ecc[2] ^ calc_ecc[2];
>> + b = b0 | (b1 << 8) | (b2 << 16);
>> +
>> + /* No errors */
>> + if (likely(!b))
>> + return 0;
>> +
>> + /* Calculate bit position */
>> + for (i = 0; i < 3; i++) {
>> + switch (b % 4) {
>> + case 2:
>> + bit_position += shifting;
>> + case 1:
>> + break;
>> + default:
>> + return -EBADMSG;
>> + }
>> + shifting <<= 1;
>> + b >>= 2;
>> + }
>> +
>> + /* Calculate byte position */
>> + shifting = 1;
>> + for (i = 0; i < 9; i++) {
>> + switch (b % 4) {
>> + case 2:
>> + byte_addr += shifting;
>> + case 1:
>> + break;
>> + default:
>> + return -EBADMSG;
>> + }
>> + shifting <<= 1;
>> + b >>= 2;
>> + }
>> +
>> + /* Flip the bit */
>> + dat[byte_addr] ^= (1 << bit_position);
>> +
>> + return 1;
>> +}
>> +
>> +/* BCH algorithm correction */
>> +static int stm32_fmc2_bch_decode(int eccsize, u8 *dat, u32 *ecc_sta)
>> +{
>> + u32 bchdsr0 = ecc_sta[0];
>> + u32 bchdsr1 = ecc_sta[1];
>> + u32 bchdsr2 = ecc_sta[2];
>> + u32 bchdsr3 = ecc_sta[3];
>> + u32 bchdsr4 = ecc_sta[4];
>> + u16 pos[8];
>> + int i, den;
>> + unsigned int nb_errs = 0;
>> +
>> + /* No errors found */
>> + if (likely(!(bchdsr0 & FMC2_BCHDSR0_DEF)))
>> + return 0;
>> +
>> + /* Too many errors detected */
>> + if (unlikely(bchdsr0 & FMC2_BCHDSR0_DUE))
>> + return -EBADMSG;
>> +
>> + pos[0] = bchdsr1 & FMC2_BCHDSR1_EBP1_MASK;
>> + pos[1] = (bchdsr1 & FMC2_BCHDSR1_EBP2_MASK) >> FMC2_BCHDSR1_EBP2_SHIFT;
>> + pos[2] = bchdsr2 & FMC2_BCHDSR2_EBP3_MASK;
>> + pos[3] = (bchdsr2 & FMC2_BCHDSR2_EBP4_MASK) >> FMC2_BCHDSR2_EBP4_SHIFT;
>> + pos[4] = bchdsr3 & FMC2_BCHDSR3_EBP5_MASK;
>> + pos[5] = (bchdsr3 & FMC2_BCHDSR3_EBP6_MASK) >> FMC2_BCHDSR3_EBP6_SHIFT;
>> + pos[6] = bchdsr4 & FMC2_BCHDSR4_EBP7_MASK;
>> + pos[7] = (bchdsr4 & FMC2_BCHDSR4_EBP8_MASK) >> FMC2_BCHDSR4_EBP8_SHIFT;
>> +
>> + den = (bchdsr0 & FMC2_BCHDSR0_DEN_MASK) >> FMC2_BCHDSR0_DEN_SHIFT;
>> + for (i = 0; i < den; i++) {
>> + if (pos[i] < eccsize * 8) {
>> + change_bit(pos[i], (unsigned long *)dat);
>> + nb_errs++;
>> + }
>> + }
>> +
>> + return nb_errs;
>> +}
>> +
>> +/* Sequencer read/write configuration */
>> +static void stm32_fmc2_rw_page_init(struct stm32_fmc2 *fmc2, int page,
>> + int raw, bool write_data)
>> +{
>> + struct nand_chip *chip = &fmc2->chip;
>> + struct mtd_info *mtd = nand_to_mtd(chip);
>> + u32 csqcfgr1, csqcfgr2, csqcfgr3;
>> + u32 csqar1, csqar2;
>> + u32 ecc_offset = mtd->writesize + FMC2_BBM_LEN;
>> + u32 pcr = readl_relaxed(fmc2->io_base + FMC2_PCR);
>> +
>> + if (write_data)
>> + pcr |= FMC2_PCR_WEN;
>> + else
>> + pcr &= ~FMC2_PCR_WEN;
>> + writel_relaxed(pcr, fmc2->io_base + FMC2_PCR);
>> +
>> + /*
>> + * - Set Program Page/Page Read command
>> + * - Enable DMA request data
>> + * - Set timings
>> + */
>> + csqcfgr1 = FMC2_CSQCFGR1_DMADEN | FMC2_CSQCFGR1_CMD1T;
>> + if (write_data)
>> + csqcfgr1 |= FMC2_CSQCFGR1_CMD1(NAND_CMD_SEQIN);
>> + else
>> + csqcfgr1 |= FMC2_CSQCFGR1_CMD1(NAND_CMD_READ0) |
>> + FMC2_CSQCFGR1_CMD2EN |
>> + FMC2_CSQCFGR1_CMD2(NAND_CMD_READSTART) |
>> + FMC2_CSQCFGR1_CMD2T;
>> +
>> + /*
>> + * - Set Random Data Input/Random Data Read command
>> + * - Enable the sequencer to access the Spare data area
>> + * - Enable DMA request status decoding for read
>> + * - Set timings
>> + */
>> + if (write_data)
>> + csqcfgr2 = FMC2_CSQCFGR2_RCMD1(NAND_CMD_RNDIN);
>> + else
>> + csqcfgr2 = FMC2_CSQCFGR2_RCMD1(NAND_CMD_RNDOUT) |
>> + FMC2_CSQCFGR2_RCMD2EN |
>> + FMC2_CSQCFGR2_RCMD2(NAND_CMD_RNDOUTSTART) |
>> + FMC2_CSQCFGR2_RCMD1T |
>> + FMC2_CSQCFGR2_RCMD2T;
>> + if (!raw) {
>> + csqcfgr2 |= write_data ? 0 : FMC2_CSQCFGR2_DMASEN;
>> + csqcfgr2 |= FMC2_CSQCFGR2_SQSDTEN;
>> + }
>> +
>> + /*
>> + * - Set the number of sectors to be written
>> + * - Set timings
>> + */
>> + csqcfgr3 = FMC2_CSQCFGR3_SNBR(chip->ecc.steps - 1);
>> + if (write_data) {
>> + csqcfgr3 |= FMC2_CSQCFGR3_RAC2T;
>> + if (chip->chipsize > SZ_128M)
>> + csqcfgr3 |= FMC2_CSQCFGR3_AC5T;
>> + else
>> + csqcfgr3 |= FMC2_CSQCFGR3_AC4T;
>> + }
>> +
>> + /*
>> + * Set the fourth first address cycles
>> + * Byte 1 and byte 2 => column, we start at 0x0
>> + * Byte 3 and byte 4 => page
>> + */
>> + csqar1 = FMC2_CSQCAR1_ADDC3(page);
>> + csqar1 |= FMC2_CSQCAR1_ADDC4(page >> 8);
>> +
>> + /*
>> + * - Set chip enable number
>> + * - Set ecc byte offset in the spare area
>> + * - Calculate the number of address cycles to be issued
>> + * - Set byte 5 of address cycle if needed
>> + */
>> + csqar2 = FMC2_CSQCAR2_NANDCEN(fmc2->cs_sel);
>> + if (chip->options & NAND_BUSWIDTH_16)
>> + csqar2 |= FMC2_CSQCAR2_SAO(ecc_offset >> 1);
>> + else
>> + csqar2 |= FMC2_CSQCAR2_SAO(ecc_offset);
>> + if (chip->chipsize > SZ_128M) {
>> + csqcfgr1 |= FMC2_CSQCFGR1_ACYNBR(5);
>> + csqar2 |= FMC2_CSQCAR2_ADDC5(page >> 16);
>> + } else {
>> + csqcfgr1 |= FMC2_CSQCFGR1_ACYNBR(4);
>> + }
>> +
>> + writel_relaxed(csqcfgr1, fmc2->io_base + FMC2_CSQCFGR1);
>> + writel_relaxed(csqcfgr2, fmc2->io_base + FMC2_CSQCFGR2);
>> + writel_relaxed(csqcfgr3, fmc2->io_base + FMC2_CSQCFGR3);
>> + writel_relaxed(csqar1, fmc2->io_base + FMC2_CSQAR1);
>> + writel_relaxed(csqar2, fmc2->io_base + FMC2_CSQAR2);
>> +}
>> +
>> +static void stm32_fmc2_dma_callback(void *arg)
>> +{
>> + complete((struct completion *)arg);
>> +}
>> +
>> +/* Read/write data from/to a page */
>> +static int stm32_fmc2_xfer(struct stm32_fmc2 *fmc2, const u8 *buf,
>> + int raw, bool write_data)
>> +{
>> + struct nand_chip *chip = &fmc2->chip;
>> + struct dma_async_tx_descriptor *desc_data, *desc_ecc;
>> + struct scatterlist *sg;
>> + struct dma_chan *dma_ch = fmc2->dma_rx_ch;
>> + enum dma_data_direction dma_data_dir = DMA_FROM_DEVICE;
>> + enum dma_transfer_direction dma_transfer_dir = DMA_DEV_TO_MEM;
>> + u32 csqcr = readl_relaxed(fmc2->io_base + FMC2_CSQCR);
>> + int eccsteps = chip->ecc.steps;
>> + int eccsize = chip->ecc.size;
>> + const u8 *p = buf;
>> + int s, ret;
>> +
>> + /* Configure DMA data */
>> + if (write_data) {
>> + dma_data_dir = DMA_TO_DEVICE;
>> + dma_transfer_dir = DMA_MEM_TO_DEV;
>> + dma_ch = fmc2->dma_tx_ch;
>> + }
>> +
>> + for_each_sg(fmc2->dma_data_sg.sgl, sg, eccsteps, s) {
>> + sg_set_buf(sg, p, eccsize);
>> + p += eccsize;
>> + }
>> +
>> + ret = dma_map_sg(fmc2->dev, fmc2->dma_data_sg.sgl,
>> + eccsteps, dma_data_dir);
>> + if (ret < 0)
>> + return ret;
>> +
>> + desc_data = dmaengine_prep_slave_sg(dma_ch, fmc2->dma_data_sg.sgl,
>> + eccsteps, dma_transfer_dir,
>> + DMA_PREP_INTERRUPT);
>> + if (!desc_data) {
>> + ret = -ENOMEM;
>> + goto err_unmap_data;
>> + }
>> +
>> + reinit_completion(&fmc2->dma_data_complete);
>> + reinit_completion(&fmc2->complete);
>> + desc_data->callback = stm32_fmc2_dma_callback;
>> + desc_data->callback_param = &fmc2->dma_data_complete;
>> + ret = dma_submit_error(dmaengine_submit(desc_data));
>> + if (ret)
>> + goto err_unmap_data;
>> +
>> + dma_async_issue_pending(dma_ch);
>> +
>> + if (!write_data && !raw) {
>> + /* Configure DMA ecc status */
>> + p = fmc2->ecc_buf;
>> + for_each_sg(fmc2->dma_ecc_sg.sgl, sg, eccsteps, s) {
>> + sg_set_buf(sg, p, fmc2->dma_ecc_len);
>> + p += fmc2->dma_ecc_len;
>> + }
>> +
>> + ret = dma_map_sg(fmc2->dev, fmc2->dma_ecc_sg.sgl,
>> + eccsteps, dma_data_dir);
>> + if (ret < 0)
>> + goto err_unmap_data;
>> +
>> + desc_ecc = dmaengine_prep_slave_sg(fmc2->dma_ecc_ch,
>> + fmc2->dma_ecc_sg.sgl,
>> + eccsteps, dma_transfer_dir,
>> + DMA_PREP_INTERRUPT);
>> + if (!desc_ecc) {
>> + ret = -ENOMEM;
>> + goto err_unmap_ecc;
>> + }
>> +
>> + reinit_completion(&fmc2->dma_ecc_complete);
>> + desc_ecc->callback = stm32_fmc2_dma_callback;
>> + desc_ecc->callback_param = &fmc2->dma_ecc_complete;
>> + ret = dma_submit_error(dmaengine_submit(desc_ecc));
>> + if (ret)
>> + goto err_unmap_ecc;
>> +
>> + dma_async_issue_pending(fmc2->dma_ecc_ch);
>> + }
>> +
>> + stm32_fmc2_clear_seq_irq(fmc2);
>> + stm32_fmc2_enable_seq_irq(fmc2);
>> +
>> + /* Start the transfer */
>> + csqcr |= FMC2_CSQCR_CSQSTART;
>> + writel_relaxed(csqcr, fmc2->io_base + FMC2_CSQCR);
>> +
>> + /* Wait end of sequencer transfer */
>> + if (!wait_for_completion_timeout(&fmc2->complete,
>> + msecs_to_jiffies(1000))) {
>> + dev_err(fmc2->dev, "seq timeout\n");
>> + stm32_fmc2_disable_seq_irq(fmc2);
>> + dmaengine_terminate_all(dma_ch);
>> + if (!write_data && !raw)
>> + dmaengine_terminate_all(fmc2->dma_ecc_ch);
>> + ret = -ETIMEDOUT;
>> + goto err_unmap_ecc;
>> + }
>> +
>> + /* Wait DMA data transfer completion */
>> + if (!wait_for_completion_timeout(&fmc2->dma_data_complete,
>> + msecs_to_jiffies(100))) {
>> + dev_err(fmc2->dev, "data DMA timeout\n");
>> + dmaengine_terminate_all(dma_ch);
>> + ret = -ETIMEDOUT;
>> + }
>> +
>> + /* Wait DMA ecc transfer completion */
>> + if (!write_data && !raw) {
>> + if (!wait_for_completion_timeout(&fmc2->dma_ecc_complete,
>> + msecs_to_jiffies(100))) {
>> + dev_err(fmc2->dev, "ecc DMA timeout\n");
>> + dmaengine_terminate_all(fmc2->dma_ecc_ch);
>> + ret = -ETIMEDOUT;
>> + }
>> + }
>> +
>> +err_unmap_ecc:
>> + if (!write_data && !raw)
>> + dma_unmap_sg(fmc2->dev, fmc2->dma_ecc_sg.sgl,
>> + eccsteps, dma_data_dir);
>> +
>> +err_unmap_data:
>> + dma_unmap_sg(fmc2->dev, fmc2->dma_data_sg.sgl, eccsteps, dma_data_dir);
>> +
>> + return ret;
>> +}
>> +
>> +static int stm32_fmc2_sequencer_write(struct nand_chip *chip,
>> + const u8 *buf, int oob_required,
>> + int page, int raw)
>> +{
>> + struct mtd_info *mtd = nand_to_mtd(chip);
>> + struct stm32_fmc2 *fmc2 = nand_get_controller_data(chip);
>> + int ret;
>> +
>> + /* Configure the sequencer */
>> + stm32_fmc2_rw_page_init(fmc2, page, raw, true);
>> +
>> + /* Write the page */
>> + ret = stm32_fmc2_xfer(fmc2, buf, raw, true);
>> + if (ret)
>> + return ret;
>> +
>> + /* Write oob */
>> + if (oob_required) {
>> + ret = nand_change_write_column_op(chip, mtd->writesize,
>> + chip->oob_poi, mtd->oobsize,
>> + false);
>> + if (ret)
>> + return ret;
>> + }
>> +
>> + return nand_prog_page_end_op(chip);
>> +}
>> +
>> +static int stm32_fmc2_sequencer_write_page(struct nand_chip *chip,
>> + const uint8_t *buf,
>> + int oob_required,
>> + int page)
>> +{
>> + return stm32_fmc2_sequencer_write(chip, buf, oob_required, page, false);
>> +}
>> +
>> +static int stm32_fmc2_sequencer_write_page_raw(struct nand_chip *chip,
>> + const uint8_t *buf,
>> + int oob_required,
>> + int page)
>> +{
>> + return stm32_fmc2_sequencer_write(chip, buf, oob_required, page, true);
>> +}
>> +
>> +/*
>> + * Get a status indicating which sectors have errors
>> + * Only available when the sequencer is used (BCH only)
>> + */
>> +static inline u16 stm32_fmc2_get_mapping_status(struct stm32_fmc2 *fmc2)
>> +{
>> + u32 csqemsr = readl_relaxed(fmc2->io_base + FMC2_CSQEMSR);
>> +
>> + return csqemsr & FMC2_CSQEMSR_SEM;
>> +}
>> +
>> +static int stm32_fmc2_sequencer_read_page(struct nand_chip *chip,
>> + uint8_t *buf,
>> + int oob_required,
>> + int page)
>> +{
>> + struct mtd_info *mtd = nand_to_mtd(chip);
>> + struct stm32_fmc2 *fmc2 = nand_get_controller_data(chip);
>> + int i, s, ret, eccsize = chip->ecc.size;
>> + int eccbytes = chip->ecc.bytes;
>> + int eccsteps = chip->ecc.steps;
>> + int eccstrength = chip->ecc.strength;
>> + u8 *p = buf;
>> + u8 *ecc_calc = chip->ecc.calc_buf;
>> + u8 *ecc_code = chip->ecc.code_buf;
>> + u32 *ecc_sta = (u32 *)fmc2->ecc_buf;
>> + u16 sta_map;
>> + unsigned int max_bitflips = 0;
>> +
>> + /* Configure the sequencer */
>> + stm32_fmc2_rw_page_init(fmc2, page, 0, false);
>> +
>> + /* Read the page */
>> + ret = stm32_fmc2_xfer(fmc2, buf, 0, false);
>> + if (ret)
>> + return ret;
>> +
>> + sta_map = stm32_fmc2_get_mapping_status(fmc2);
>> +
>> + /* Check if errors happen */
>> + if (likely(!sta_map)) {
>> + if (oob_required)
>> + return nand_change_read_column_op(chip, mtd->writesize,
>> + chip->oob_poi,
>> + mtd->oobsize, false);
>> +
>> + return 0;
>> + }
>> +
>> + /* Read oob */
>> + ret = nand_change_read_column_op(chip, mtd->writesize,
>> + chip->oob_poi, mtd->oobsize, false);
>> + if (ret)
>> + return ret;
>> +
>> + ret = mtd_ooblayout_get_eccbytes(mtd, ecc_code, chip->oob_poi, 0,
>> + chip->ecc.total);
>> + if (ret)
>> + return ret;
>> +
>> + /* Correct data */
>> + for (i = 0, s = 0; s < eccsteps; s++, i += eccbytes, p += eccsize) {
>> + int stat = 0;
>> +
>> + if (eccstrength == FMC2_ECC_HAM) {
>> + /* Ecc_sta = FMC2_HECCR */
>> + if (sta_map & BIT(s)) {
>> + stm32_fmc2_ham_set_ecc(*ecc_sta, &ecc_calc[i]);
>> + stat = chip->ecc.correct(chip, p, &ecc_code[i],
>> + &ecc_calc[i]);
>> + }
>> + ecc_sta++;
>> + } else {
>> + /*
>> + * Ecc_sta[0] = FMC2_BCHDSR0
>> + * Ecc_sta[1] = FMC2_BCHDSR1
>> + * Ecc_sta[2] = FMC2_BCHDSR2
>> + * Ecc_sta[3] = FMC2_BCHDSR3
>> + * Ecc_sta[4] = FMC2_BCHDSR4
>> + */
>> + if (sta_map & BIT(s))
>> + stat = stm32_fmc2_bch_decode(chip->ecc.size,
>> + p, ecc_sta);
>> + ecc_sta += 5;
>> + }
>> +
>> + if (stat == -EBADMSG)
>> + /* Check for empty pages with bitflips */
>> + stat = nand_check_erased_ecc_chunk(p, eccsize,
>> + &ecc_code[i],
>> + eccbytes,
>> + NULL, 0,
>> + eccstrength);
>> +
>> + 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;
>> +}
>> +
>> +static int stm32_fmc2_sequencer_read_page_raw(struct nand_chip *chip,
>> + uint8_t *buf,
>> + int oob_required,
>> + int page)
>> +{
>> + struct mtd_info *mtd = nand_to_mtd(chip);
>> + struct stm32_fmc2 *fmc2 = nand_get_controller_data(chip);
>> + int ret;
>> +
>> + /* Configure the sequencer */
>> + stm32_fmc2_rw_page_init(fmc2, page, 1, false);
>> +
>> + /* Read the page */
>> + ret = stm32_fmc2_xfer(fmc2, buf, 1, false);
>> + if (ret)
>> + return ret;
>> +
>> + /* Read oob */
>> + if (oob_required)
>> + return nand_change_read_column_op(chip, mtd->writesize,
>> + chip->oob_poi, mtd->oobsize,
>> + false);
>> +
>> + return 0;
>> +}
>> +
>> +static irqreturn_t stm32_fmc2_irq(int irq, void *dev_id)
>> +{
>> + struct stm32_fmc2 *fmc2 = (struct stm32_fmc2 *)dev_id;
>> +
>> + stm32_fmc2_disable_seq_irq(fmc2);
>> +
>> + complete(&fmc2->complete);
>> +
>> + return IRQ_HANDLED;
>
> You don't have any bit to check/ack/read?

No, nothing to check.

>
>> +}
>> +
>> +void stm32_fmc2_read_data(struct nand_chip *chip, void *buf,
>> + unsigned int len, bool force_8bit)
>> +{
>> + struct stm32_fmc2 *fmc2 = nand_get_controller_data(chip);
>> + void __iomem *io_addr_r = fmc2->data_base[fmc2->cs_sel];
>> + u8 *p = buf;
>> + unsigned int i;
>> +
>> + if (force_8bit)
>> + goto read_8bit;
>> +
>> + if (IS_ALIGNED((u32)buf, sizeof(u32)) && IS_ALIGNED(len, sizeof(u32))) {
>
> If you selected BOUNCE_BUFFER in the options, buf is supposedly
> aligned, or am I missing something?

2 FMC2 internal modes can be used:
- Sequencer mode (Patch 2/3): dmas are used and NAND_USE_BOUNCE_BUFFER
option is selected.
- Manual mode (Patch 3/3): no dma channel is used and
NAND_USE_BOUNCE_BUFFER is not selected.
Should i select NAND_USE_BOUNCE_BUFFER for sequencer and manual mode,
and remove IS_ALIGNED test on buf?

>
>> + u32 *p = buf;
>> +
>> + len >>= 2;
>
> Please don't do such optimization by hand. Compilers are doing it for
> it, so let's keep the code readable. Just do a regular "/=
> sizeof(unsigned long)".

Ok, i will replace this line with: len /= sizeof(u32)

>
>> + for (i = 0; i < len; i++)
>> + p[i] = readl_relaxed(io_addr_r);
>> + return;
>> + }
>> +
>> + if (chip->options & NAND_BUSWIDTH_16) {
>> + u16 *p = buf;
>> +
>> + len >>= 1;
>
> Ditto

Ok, i will replace this line with: len /= sizeof(u16)
Same modifications will be done in stm32_fmc2_write_data function.

>
>> + for (i = 0; i < len; i++)
>> + p[i] = readw_relaxed(io_addr_r);
>> + return;
>> + }
>> +
>> +read_8bit:
>> + for (i = 0; i < len; i++)
>> + p[i] = readb_relaxed(io_addr_r);
>> +}
>> +
>> +void stm32_fmc2_write_data(struct nand_chip *chip, const void *buf,
>> + unsigned int len, bool force_8bit)
>> +{
>> + struct stm32_fmc2 *fmc2 = nand_get_controller_data(chip);
>> + void __iomem *io_addr_w = fmc2->data_base[fmc2->cs_sel];
>> + const u8 *p = buf;
>> + unsigned int i;
>> +
>> + if (force_8bit)
>> + goto write_8bit;
>> +
>> + if (IS_ALIGNED((u32)buf, sizeof(u32)) && IS_ALIGNED(len, sizeof(u32))) {
>> + const u32 *p = buf;
>> +
>> + len >>= 2;
>> + for (i = 0; i < len; i++)
>> + writel_relaxed(p[i], io_addr_w);
>> + return;
>> + }
>> +
>> + if (chip->options & NAND_BUSWIDTH_16) {
>> + const u16 *p = buf;
>> +
>> + len >>= 1;
>> + for (i = 0; i < len; i++)
>> + writew_relaxed(p[i], io_addr_w);
>> + return;
>> + }
>> +
>> +write_8bit:
>> + for (i = 0; i < len; i++)
>> + writeb_relaxed(p[i], io_addr_w);
>> +}
>> +
>> +static int stm32_fmc2_exec_op(struct nand_chip *chip,
>> + const struct nand_operation *op,
>> + bool check_only)
>
> You should probably return 0 if check_only == true, otherwise you could
> do twice each operation.

Ok.

>
>> +{
>> + struct stm32_fmc2 *fmc2 = nand_get_controller_data(chip);
>> + const struct nand_op_instr *instr = NULL;
>> + unsigned int op_id, i;
>> + int ret = 0;
>> +
>> + for (op_id = 0; op_id < op->ninstrs; op_id++) {
>> + instr = &op->instrs[op_id];
>> +
>> + switch (instr->type) {
>> + case NAND_OP_CMD_INSTR:
>> + writeb_relaxed(instr->ctx.cmd.opcode,
>> + fmc2->cmd_base[fmc2->cs_sel]);
>> + break;
>> +
>> + case NAND_OP_ADDR_INSTR:
>> + for (i = 0; i < instr->ctx.addr.naddrs; i++)
>> + writeb_relaxed(instr->ctx.addr.addrs[i],
>> + fmc2->addr_base[fmc2->cs_sel]);
>> + break;
>> +
>> + case NAND_OP_DATA_IN_INSTR:
>> + stm32_fmc2_read_data(chip, instr->ctx.data.buf.in,
>> + instr->ctx.data.len,
>> + instr->ctx.data.force_8bit);
>> + break;
>> +
>> + case NAND_OP_DATA_OUT_INSTR:
>> + stm32_fmc2_write_data(chip, instr->ctx.data.buf.out,
>> + instr->ctx.data.len,
>> + instr->ctx.data.force_8bit);
>> + break;
>> +
>> + case NAND_OP_WAITRDY_INSTR:
>> + ret = nand_soft_waitrdy(chip,
>> + instr->ctx.waitrdy.timeout_ms);
>> + break;
>> + }
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +/* Timings configuration */
>> +static void stm32_fmc2_timings_init(struct stm32_fmc2 *fmc2)
>> +{
>> + struct stm32_fmc2_timings *timings = &fmc2->timings;
>> + u32 pcr = readl_relaxed(fmc2->io_base + FMC2_PCR);
>> + u32 pmem, patt;
>> +
>> + /* Set tclr/tar timings */
>> + pcr &= ~FMC2_PCR_TCLR_MASK;
>> + pcr |= FMC2_PCR_TCLR(timings->tclr);
>> + pcr &= ~FMC2_PCR_TAR_MASK;
>> + pcr |= FMC2_PCR_TAR(timings->tar);
>> +
>> + /* Set tset/twait/thold/thiz timings in common bank */
>> + pmem = FMC2_PMEM_MEMSET(timings->tset_mem);
>> + pmem |= FMC2_PMEM_MEMWAIT(timings->twait);
>> + pmem |= FMC2_PMEM_MEMHOLD(timings->thold_mem);
>> + pmem |= FMC2_PMEM_MEMHIZ(timings->thiz);
>> +
>> + /* Set tset/twait/thold/thiz timings in attribut bank */
>> + patt = FMC2_PATT_ATTSET(timings->tset_att);
>> + patt |= FMC2_PATT_ATTWAIT(timings->twait);
>> + patt |= FMC2_PATT_ATTHOLD(timings->thold_att);
>> + patt |= FMC2_PATT_ATTHIZ(timings->thiz);
>> +
>> + writel_relaxed(pcr, fmc2->io_base + FMC2_PCR);
>> + writel_relaxed(pmem, fmc2->io_base + FMC2_PMEM);
>> + writel_relaxed(patt, fmc2->io_base + FMC2_PATT);
>> +}
>> +
>> +/* Controller initialization */
>> +static void stm32_fmc2_init(struct stm32_fmc2 *fmc2)
>> +{
>> + u32 pcr = readl_relaxed(fmc2->io_base + FMC2_PCR);
>> + u32 bcr1 = readl_relaxed(fmc2->io_base + FMC2_BCR1);
>> +
>> + /* Enable wait feature and nand flash memory bank */
>> + pcr |= FMC2_PCR_PWAITEN;
>> + pcr |= FMC2_PCR_PBKEN;
>> +
>> + /* Set buswidth to 8 bits mode for identification */
>> + pcr &= ~FMC2_PCR_PWID_MASK;
>> +
>> + /* Ecc logic is disabled */
>> + pcr &= ~FMC2_PCR_ECCEN;
>> +
>> + /* Default mode */
>> + pcr &= ~FMC2_PCR_ECCALG;
>> + pcr &= ~FMC2_PCR_BCHECC;
>> + pcr &= ~FMC2_PCR_WEN;
>> +
>> + /* Set default ecc sector size */
>> + pcr &= ~FMC2_PCR_ECCSS_MASK;
>> + pcr |= FMC2_PCR_ECCSS(FMC2_PCR_ECCSS_2048);
>> +
>> + /* Set default tclr/tar timings */
>> + pcr &= ~FMC2_PCR_TCLR_MASK;
>> + pcr |= FMC2_PCR_TCLR(FMC2_PCR_TCLR_DEFAULT);
>> + pcr &= ~FMC2_PCR_TAR_MASK;
>> + pcr |= FMC2_PCR_TAR(FMC2_PCR_TAR_DEFAULT);
>> +
>> + /* Enable FMC2 controller */
>> + bcr1 |= FMC2_BCR1_FMC2EN;
>> +
>> + writel_relaxed(bcr1, fmc2->io_base + FMC2_BCR1);
>> + writel_relaxed(pcr, fmc2->io_base + FMC2_PCR);
>> + writel_relaxed(FMC2_PMEM_DEFAULT, fmc2->io_base + FMC2_PMEM);
>> + writel_relaxed(FMC2_PATT_DEFAULT, fmc2->io_base + FMC2_PATT);
>> +}
>> +
>> +/* Controller configuration */
>> +static void stm32_fmc2_setup(struct stm32_fmc2 *fmc2)
>> +{
>> + struct nand_chip *chip = &fmc2->chip;
>> + u32 pcr = readl_relaxed(fmc2->io_base + FMC2_PCR);
>> +
>> + /* Configure in HAMMING by default */
>
> In other comments you use "Hamming", not "HAMMING".
>
> And this comment is weird, you don't configure for Hamming below. Maybe
> you meant that the controller is by default configured to work with
> Hamming error detection?

Yes, it's true. Hamming error detection is set by default. Below
implementation configures the controller in BCH4 or BCH8. I will modify
the comment.

>
>> + if (chip->ecc.strength == FMC2_ECC_BCH8) {
>> + pcr |= FMC2_PCR_ECCALG;
>> + pcr |= FMC2_PCR_BCHECC;
>> + } else if (chip->ecc.strength == FMC2_ECC_BCH4) {
>> + pcr |= FMC2_PCR_ECCALG;
>> + }
>> +
>> + /* Set buswidth */
>> + if (chip->options & NAND_BUSWIDTH_16)
>> + pcr |= FMC2_PCR_PWID(FMC2_PCR_PWID_BUSWIDTH_16);
>> +
>> + /* Set ecc sector size */
>> + pcr &= ~FMC2_PCR_ECCSS_MASK;
>> + pcr |= FMC2_PCR_ECCSS(FMC2_PCR_ECCSS_512);
>> +
>> + writel_relaxed(pcr, fmc2->io_base + FMC2_PCR);
>> +}
>> +
>> +/* Controller timings */
>> +static void stm32_fmc2_calc_timings(struct stm32_fmc2 *fmc2,
>> + const struct nand_sdr_timings *sdrt,
>> + struct stm32_fmc2_timings *tims)
>> +{
>> + unsigned long hclk = clk_get_rate(fmc2->clk);
>> + unsigned long hclkp = NSEC_PER_SEC / (hclk / 1000);
>> + int tar, tclr, thiz, twait, tset_mem, tset_att, thold_mem, thold_att;
>> +
>> + tar = hclkp;
>> + if (tar < sdrt->tAR_min)
>> + tar = sdrt->tAR_min;
>> + tims->tar = DIV_ROUND_UP(tar, hclkp) - 1;
>> + if (tims->tar > FMC2_PCR_TIMING_MASK)
>> + tims->tar = FMC2_PCR_TIMING_MASK;
>> +
>> + tclr = hclkp;
>> + if (tclr < sdrt->tCLR_min)
>> + tclr = sdrt->tCLR_min;
>> + tims->tclr = DIV_ROUND_UP(tclr, hclkp) - 1;
>> + if (tims->tclr > FMC2_PCR_TIMING_MASK)
>> + tims->tclr = FMC2_PCR_TIMING_MASK;
>> +
>> + tims->thiz = FMC2_THIZ;
>> + thiz = (tims->thiz + 1) * hclkp;
>> +
>> + /*
>> + * tWAIT > tRP
>> + * tWAIT > tWP
>> + * tWAIT > tREA + tIO
>> + */
>> + twait = hclkp;
>> + if (twait < sdrt->tRP_min)
>> + twait = sdrt->tRP_min;
>> + if (twait < sdrt->tWP_min)
>> + twait = sdrt->tWP_min;
>> + if (twait < sdrt->tREA_max + FMC2_TIO)
>> + twait = sdrt->tREA_max + FMC2_TIO;
>> + tims->twait = DIV_ROUND_UP(twait, hclkp);
>> + if (tims->twait == 0)
>> + tims->twait = 1;
>> + else if (tims->twait > FMC2_PMEM_PATT_TIMING_MASK)
>> + tims->twait = FMC2_PMEM_PATT_TIMING_MASK;
>> +
>> + /*
>> + * tSETUP_MEM > tCS - tWAIT
>> + * tSETUP_MEM > tALS - tWAIT
>> + * tSETUP_MEM > tDS - (tWAIT - tHIZ)
>> + */
>> + tset_mem = hclkp;
>> + if (sdrt->tCS_min > twait && (tset_mem < sdrt->tCS_min - twait))
>> + tset_mem = sdrt->tCS_min - twait;
>> + if (sdrt->tALS_min > twait && (tset_mem < sdrt->tALS_min - twait))
>> + tset_mem = sdrt->tALS_min - twait;
>> + if (twait > thiz && (sdrt->tDS_min > twait - thiz) &&
>> + (tset_mem < sdrt->tDS_min - (twait - thiz)))
>> + tset_mem = sdrt->tDS_min - (twait - thiz);
>> + tims->tset_mem = DIV_ROUND_UP(tset_mem, hclkp);
>> + if (tims->tset_mem == 0)
>> + tims->tset_mem = 1;
>> + else if (tims->tset_mem > FMC2_PMEM_PATT_TIMING_MASK)
>> + tims->tset_mem = FMC2_PMEM_PATT_TIMING_MASK;
>> +
>> + /*
>> + * tHOLD_MEM > tCH
>> + * tHOLD_MEM > tREH - tSETUP_MEM
>> + * tHOLD_MEM > max(tRC, tWC) - (tSETUP_MEM + tWAIT)
>> + */
>> + thold_mem = hclkp;
>> + if (thold_mem < sdrt->tCH_min)
>> + thold_mem = sdrt->tCH_min;
>> + if (sdrt->tREH_min > tset_mem &&
>> + (thold_mem < sdrt->tREH_min - tset_mem))
>> + thold_mem = sdrt->tREH_min - tset_mem;
>> + if ((sdrt->tRC_min > tset_mem + twait) &&
>> + (thold_mem < sdrt->tRC_min - (tset_mem + twait)))
>> + thold_mem = sdrt->tRC_min - (tset_mem + twait);
>> + if ((sdrt->tWC_min > tset_mem + twait) &&
>> + (thold_mem < sdrt->tWC_min - (tset_mem + twait)))
>> + thold_mem = sdrt->tWC_min - (tset_mem + twait);
>> + tims->thold_mem = DIV_ROUND_UP(thold_mem, hclkp);
>> + if (tims->thold_mem == 0)
>> + tims->thold_mem = 1;
>> + else if (tims->thold_mem > FMC2_PMEM_PATT_TIMING_MASK)
>> + tims->thold_mem = FMC2_PMEM_PATT_TIMING_MASK;
>> +
>> + /*
>> + * tSETUP_ATT > tCS - tWAIT
>> + * tSETUP_ATT > tCLS - tWAIT
>> + * tSETUP_ATT > tALS - tWAIT
>> + * tSETUP_ATT > tRHW - tHOLD_MEM
>> + * tSETUP_ATT > tDS - (tWAIT - tHIZ)
>> + */
>> + tset_att = hclkp;
>> + if (sdrt->tCS_min > twait && (tset_att < sdrt->tCS_min - twait))
>> + tset_att = sdrt->tCS_min - twait;
>> + if (sdrt->tCLS_min > twait && (tset_att < sdrt->tCLS_min - twait))
>> + tset_att = sdrt->tCLS_min - twait;
>> + if (sdrt->tALS_min > twait && (tset_att < sdrt->tALS_min - twait))
>> + tset_att = sdrt->tALS_min - twait;
>> + if (sdrt->tRHW_min > thold_mem &&
>> + (tset_att < sdrt->tRHW_min - thold_mem))
>> + tset_att = sdrt->tRHW_min - thold_mem;
>> + if (twait > thiz && (sdrt->tDS_min > twait - thiz) &&
>> + (tset_att < sdrt->tDS_min - (twait - thiz)))
>> + tset_att = sdrt->tDS_min - (twait - thiz);
>> + tims->tset_att = DIV_ROUND_UP(tset_att, hclkp);
>> + if (tims->tset_att == 0)
>> + tims->tset_att = 1;
>> + else if (tims->tset_att > FMC2_PMEM_PATT_TIMING_MASK)
>> + tims->tset_att = FMC2_PMEM_PATT_TIMING_MASK;
>> +
>> + /*
>> + * tHOLD_ATT > tALH
>> + * tHOLD_ATT > tCH
>> + * tHOLD_ATT > tCLH
>> + * tHOLD_ATT > tCOH
>> + * tHOLD_ATT > tDH
>> + * tHOLD_ATT > tWB + tIO + tSYNC - tSETUP_MEM
>> + * tHOLD_ATT > tADL - tSETUP_MEM
>> + * tHOLD_ATT > tWH - tSETUP_MEM
>> + * tHOLD_ATT > tWHR - tSETUP_MEM
>> + * tHOLD_ATT > tRC - (tSETUP_ATT + tWAIT)
>> + * tHOLD_ATT > tWC - (tSETUP_ATT + tWAIT)
>> + */
>> + thold_att = hclkp;
>> + if (thold_att < sdrt->tALH_min)
>> + thold_att = sdrt->tALH_min;
>> + if (thold_att < sdrt->tCH_min)
>> + thold_att = sdrt->tCH_min;
>> + if (thold_att < sdrt->tCLH_min)
>> + thold_att = sdrt->tCLH_min;
>> + if (thold_att < sdrt->tCOH_min)
>> + thold_att = sdrt->tCOH_min;
>> + if (thold_att < sdrt->tDH_min)
>> + thold_att = sdrt->tDH_min;
>> + if ((sdrt->tWB_max + FMC2_TIO + FMC2_TSYNC > tset_mem) &&
>> + (thold_att < sdrt->tWB_max + FMC2_TIO + FMC2_TSYNC - tset_mem))
>> + thold_att = sdrt->tWB_max + FMC2_TIO + FMC2_TSYNC - tset_mem;
>> + if (sdrt->tADL_min > tset_mem &&
>> + (thold_att < sdrt->tADL_min - tset_mem))
>> + thold_att = sdrt->tADL_min - tset_mem;
>> + if (sdrt->tWH_min > tset_mem &&
>> + (thold_att < sdrt->tWH_min - tset_mem))
>> + thold_att = sdrt->tWH_min - tset_mem;
>> + if (sdrt->tWHR_min > tset_mem &&
>> + (thold_att < sdrt->tWHR_min - tset_mem))
>> + thold_att = sdrt->tWHR_min - tset_mem;
>> + if ((sdrt->tRC_min > tset_att + twait) &&
>> + (thold_att < sdrt->tRC_min - (tset_att + twait)))
>> + thold_att = sdrt->tRC_min - (tset_att + twait);
>> + if ((sdrt->tWC_min > tset_att + twait) &&
>> + (thold_att < sdrt->tWC_min - (tset_att + twait)))
>> + thold_att = sdrt->tWC_min - (tset_att + twait);
>> + tims->thold_att = DIV_ROUND_UP(thold_att, hclkp);
>> + if (tims->thold_att == 0)
>> + tims->thold_att = 1;
>> + else if (tims->thold_att > FMC2_PMEM_PATT_TIMING_MASK)
>> + tims->thold_att = FMC2_PMEM_PATT_TIMING_MASK;
>> +}
>> +
>> +static int stm32_fmc2_setup_interface(struct nand_chip *chip, int chipnr,
>> + const struct nand_data_interface *conf)
>> +{
>> + struct stm32_fmc2 *fmc2 = nand_get_controller_data(chip);
>> + struct stm32_fmc2_timings tims;
>> + const struct nand_sdr_timings *sdrt;
>> +
>> + sdrt = nand_get_sdr_timings(conf);
>> + if (IS_ERR(sdrt))
>> + return PTR_ERR(sdrt);
>> +
>> + stm32_fmc2_calc_timings(fmc2, sdrt, &tims);
>
> Why do you need 'tims' if the only use is to memcpy it in
> fmc2->timings? I suppose you can get rid of it.

Yes, it is not needed to use a local variable.

>
>> +
>> + if (chipnr == NAND_DATA_IFACE_CHECK_ONLY)
>> + return 0;
>
> If the controller may support all the timing modes, then you can
> certainly return on CHECK_ONLY before *_calc_timings().

Yes, i will move this check before stm32_fmc2_calc_timings().

>
>> +
>> + /* Save and apply timings */
>> + memcpy(&fmc2->timings, &tims, sizeof(tims));
>> + stm32_fmc2_timings_init(fmc2);
>> +
>> + return 0;
>> +}
>> +
>> +/* DMA configuration */
>> +static int stm32_fmc2_dma_setup(struct stm32_fmc2 *fmc2, u8 nbsect)
>> +{
>> + struct nand_chip *chip = &fmc2->chip;
>> + struct dma_slave_config dma_cfg;
>> + int ret;
>> +
>> + memset(&dma_cfg, 0, sizeof(dma_cfg));
>> + dma_cfg.src_addr = fmc2->data_phys_addr[fmc2->cs_sel];
>> + dma_cfg.dst_addr = fmc2->data_phys_addr[fmc2->cs_sel];
>> + dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>> + dma_cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>> + dma_cfg.src_maxburst = 32;
>> + dma_cfg.dst_maxburst = 32;
>> +
>> + fmc2->dma_tx_ch = dma_request_slave_channel(fmc2->dev, "tx");
>> + if (fmc2->dma_tx_ch) {
>> + ret = dmaengine_slave_config(fmc2->dma_tx_ch, &dma_cfg);
>> + if (ret) {
>> + dev_err(fmc2->dev, "data tx DMA engine slave config failed\n");
>> + return ret;
>> + }
>> + }
>> +
>> + fmc2->dma_rx_ch = dma_request_slave_channel(fmc2->dev, "rx");
>> + if (fmc2->dma_rx_ch) {
>> + ret = dmaengine_slave_config(fmc2->dma_rx_ch, &dma_cfg);
>> + if (ret) {
>> + dev_err(fmc2->dev, "data rx DMA engine slave config failed\n");
>> + return ret;
>> + }
>> +
>> + fmc2->dma_ecc_ch = dma_request_slave_channel(fmc2->dev, "ecc");
>> + if (fmc2->dma_ecc_ch) {
>> + /*
>> + * HAMMING: we read HECCR register
>> + * BCH4/BCH8: we read BCHDSRSx registers
>> + */
>> + memset(&dma_cfg, 0, sizeof(dma_cfg));
>> + dma_cfg.src_addr = fmc2->io_phys_addr;
>> + dma_cfg.src_addr += chip->ecc.strength == FMC2_ECC_HAM ?
>> + FMC2_HECCR : FMC2_BCHDSR0;
>> + dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>> +
>> + ret = dmaengine_slave_config(fmc2->dma_ecc_ch,
>> + &dma_cfg);
>> + if (ret) {
>> + dev_err(fmc2->dev, "ecc DMA engine slave config failed\n");
>> + return ret;
>> + }
>> +
>> + ret = sg_alloc_table(&fmc2->dma_ecc_sg,
>> + nbsect, GFP_KERNEL);
>> + if (ret)
>> + return ret;
>> +
>> + /* Calculate ecc length needed for one sector */
>> + fmc2->dma_ecc_len = chip->ecc.strength == FMC2_ECC_HAM ?
>> + FMC2_HECCR_LEN : FMC2_BCHDSRS_LEN;
>> +
>> + /* Allocate a buffer to store ecc status registers */
>> + fmc2->ecc_buf = devm_kzalloc(fmc2->dev,
>> + fmc2->dma_ecc_len * nbsect,
>> + GFP_KERNEL);
>> + if (!fmc2->ecc_buf)
>> + return -ENOMEM;
>> + } else {
>> + dev_err(fmc2->dev, "ecc DMA not defined in the device tree\n");
>> + return -ENOENT;
>> + }
>> + }
>> +
>> + if (fmc2->dma_tx_ch && fmc2->dma_rx_ch) {
>> + ret = sg_alloc_table(&fmc2->dma_data_sg, nbsect, GFP_KERNEL);
>> + if (ret)
>> + return ret;
>> +
>> + init_completion(&fmc2->dma_data_complete);
>> + init_completion(&fmc2->dma_ecc_complete);
>> + } else {
>> + dev_err(fmc2->dev, "rx/tx DMA not defined in the device tree\n");
>> + return -ENOENT;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +/* NAND callbacks setup */
>> +static void stm32_fmc2_nand_callbacks_setup(struct stm32_fmc2 *fmc2)
>> +{
>> + struct nand_chip *chip = &fmc2->chip;
>> +
>> + /* Specific callbacks to read/write a page */
>> + chip->ecc.correct = stm32_fmc2_ham_correct;
>> + chip->ecc.write_page = stm32_fmc2_sequencer_write_page;
>> + chip->ecc.read_page = stm32_fmc2_sequencer_read_page;
>> + chip->ecc.write_page_raw = stm32_fmc2_sequencer_write_page_raw;
>> + chip->ecc.read_page_raw = stm32_fmc2_sequencer_read_page_raw;
>> + chip->options |= NAND_USE_BOUNCE_BUFFER;
>> +
>> + /* Specific configurations depending on the algo used */
>> + if (chip->ecc.strength == FMC2_ECC_HAM)
>> + chip->ecc.bytes = chip->options & NAND_BUSWIDTH_16 ? 4 : 3;
>> + else if (chip->ecc.strength == FMC2_ECC_BCH8)
>> + chip->ecc.bytes = chip->options & NAND_BUSWIDTH_16 ? 14 : 13;
>> + else
>> + chip->ecc.bytes = chip->options & NAND_BUSWIDTH_16 ? 8 : 7;
>> +}
>> +
>> +/* FMC2 layout */
>> +static int stm32_fmc2_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
>> + struct mtd_oob_region *oobregion)
>> +{
>> + struct nand_chip *chip = mtd_to_nand(mtd);
>> + struct nand_ecc_ctrl *ecc = &chip->ecc;
>> +
>> + if (section)
>> + return -ERANGE;
>> +
>> + oobregion->length = ecc->total;
>> + oobregion->offset = FMC2_BBM_LEN;
>> +
>> + return 0;
>> +}
>> +
>> +static int stm32_fmc2_nand_ooblayout_free(struct mtd_info *mtd, int section,
>> + struct mtd_oob_region *oobregion)
>> +{
>> + struct nand_chip *chip = mtd_to_nand(mtd);
>> + struct nand_ecc_ctrl *ecc = &chip->ecc;
>> +
>> + if (section)
>> + return -ERANGE;
>> +
>> + oobregion->length = mtd->oobsize - ecc->total - FMC2_BBM_LEN;
>> + oobregion->offset = ecc->total + FMC2_BBM_LEN;
>> +
>> + return 0;
>> +}
>> +
>> +const struct mtd_ooblayout_ops stm32_fmc2_nand_ooblayout_ops = {
>> + .ecc = stm32_fmc2_nand_ooblayout_ecc,
>> + .free = stm32_fmc2_nand_ooblayout_free,
>> +};
>> +
>> +/* FMC2 caps */
>> +static int stm32_fmc2_calc_ecc_bytes(int step_size, int strength)
>> +{
>> + /* Hamming */
>> + if (strength == FMC2_ECC_HAM)
>> + return 4;
>> +
>> + /* BCH8 */
>> + if (strength == FMC2_ECC_BCH8)
>> + return 14;
>> +
>> + /* BCH4 */
>> + return 8;
>> +}
>> +
>> +NAND_ECC_CAPS_SINGLE(stm32_fmc2_ecc_caps, stm32_fmc2_calc_ecc_bytes,
>> + FMC2_ECC_STEP_SIZE,
>> + FMC2_ECC_HAM, FMC2_ECC_BCH4, FMC2_ECC_BCH8);
>> +
>> +/* FMC2 controller ops */
>> +static int stm32_fmc2_attach_chip(struct nand_chip *chip)
>> +{
>> + struct stm32_fmc2 *fmc2 = nand_get_controller_data(chip);
>> + struct mtd_info *mtd = nand_to_mtd(chip);
>> + u8 nbsect;
>> + int ret;
>> +
>> + /*
>> + * Only NAND_ECC_HW mode is actually supported
>> + * HAMMING => ecc.strength = 1
>> + * BCH4 => ecc.strength = 4
>> + * BCH8 => ecc.strength = 8
>> + * ecc sector size = 512
>> + */
>> + if (chip->ecc.mode != NAND_ECC_HW) {
>> + dev_err(fmc2->dev, "nand_ecc_mode is not well defined in the DT\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = nand_ecc_choose_conf(chip, &stm32_fmc2_ecc_caps,
>> + mtd->oobsize - FMC2_BBM_LEN);
>> + if (ret) {
>> + dev_err(fmc2->dev, "no valid ECC settings set\n");
>> + return ret;
>> + }
>> +
>> + nbsect = mtd->writesize / chip->ecc.size;
>> + if (nbsect > FMC2_MAX_SG_COUNT) {
>> + dev_err(fmc2->dev, "nand page size is not supported\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (chip->bbt_options & NAND_BBT_USE_FLASH)
>> + chip->bbt_options |= NAND_BBT_NO_OOB;
>> +
>> + /* FMC2 setup routine */
>> + stm32_fmc2_setup(fmc2);
>> +
>> + /* DMA setup */
>> + ret = stm32_fmc2_dma_setup(fmc2, nbsect);
>> + if (ret)
>> + return ret;
>> +
>> + /* NAND callbacks setup */
>> + stm32_fmc2_nand_callbacks_setup(fmc2);
>> +
>> + /* Define ECC layout */
>> + mtd_set_ooblayout(mtd, &stm32_fmc2_nand_ooblayout_ops);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct nand_controller_ops stm32_fmc2_nand_controller_ops = {
>> + .attach_chip = stm32_fmc2_attach_chip,
>> +};
>> +
>> +/* FMC2 probe */
>> +static int stm32_fmc2_parse_child(struct device *dev,
>> + struct stm32_fmc2 *fmc2,
>> + struct device_node *dn)
>> +{
>> + u32 cs;
>> + int ret, i;
>> +
>> + if (!of_get_property(dn, "reg", &fmc2->ncs))
>> + return -EINVAL;
>> +
>> + fmc2->ncs /= sizeof(u32);
>> + if (!fmc2->ncs) {
>> + dev_err(dev, "invalid reg property size\n");
>> + return -EINVAL;
>> + }
>> +
>> + for (i = 0; i < fmc2->ncs; i++) {
>> + ret = of_property_read_u32_index(dn, "reg", i, &cs);
>> + if (ret) {
>> + dev_err(dev, "could not retrieve reg property: %d\n",
>> + ret);
>> + return ret;
>> + }
>> +
>> + if (cs > FMC2_MAX_CE) {
>> + dev_err(dev, "invalid reg value: %d\n", cs);
>> + return -EINVAL;
>> + }
>> +
>> + if (fmc2->cs_assigned & BIT(cs)) {
>> + dev_err(dev, "cs already assigned: %d\n", cs);
>> + return -EINVAL;
>> + }
>> +
>> + fmc2->cs_assigned |= BIT(cs);
>> + fmc2->cs_used[i] = cs;
>> + }
>> +
>> + /* Default cs used */
>
> s/cs/CS/

OK

>
>> + fmc2->cs_sel = fmc2->cs_used[0];
>> +
>> + /* Timings */
>> + ret = of_property_read_u8_array(dn, "st,fmc2_timings",
>> + (u8 *)&fmc2->timings,
>> + sizeof(fmc2->timings));
>> + return ret ? 0 : 1;
>> +}
>> +
>> +static int stm32_fmc2_parse_dt(struct device *dev,
>> + struct stm32_fmc2 *fmc2)
>> +{
>> + struct device_node *dn = dev->of_node;
>> + struct device_node *child;
>> + int nchips = of_get_child_count(dn);
>> + int ret = 0;
>> +
>> + if (!nchips) {
>> + dev_err(dev, "NAND chip not defined\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (nchips > 1) {
>
> If you have two CS, can't you have two NAND chips connected?
>

No HW board has been designed with 2 NAND chips connected. I am not able
to test this configuration. The driver will be improved when i will be
able to test such configuration.

>> + dev_err(dev, "too many NAND chips defined\n");
>> + return -EINVAL;
>> + }
>> +
>> + for_each_child_of_node(dn, child) {
>> + ret = stm32_fmc2_parse_child(dev, fmc2, child);
>> + if (ret < 0) {
>> + of_node_put(child);
>> + return ret;
>> + }
>> +
>> + nand_set_flash_node(&fmc2->chip, child);
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static int stm32_fmc2_probe(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct reset_control *rstc;
>> + struct stm32_fmc2 *fmc2;
>> + struct resource *res;
>> + struct mtd_info *mtd;
>> + struct nand_chip *chip;
>> + int i, j, ret, irq, timings_def;
>> +
>> + fmc2 = devm_kzalloc(dev, sizeof(*fmc2), GFP_KERNEL);
>> + if (!fmc2)
>> + return -ENOMEM;
>> +
>> + timings_def = stm32_fmc2_parse_dt(dev, fmc2);
>> + if (timings_def < 0)
>> + return timings_def;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + fmc2->io_base = devm_ioremap_resource(dev, res);
>> + if (IS_ERR(fmc2->io_base))
>> + return PTR_ERR(fmc2->io_base);
>> +
>> + fmc2->io_phys_addr = res->start;
>> +
>> + for (i = 0, j = 1; i < FMC2_MAX_CE; i++, j += 3) {
>
> Maybe naming i 'chip_id' and j 'mem_region' or something else, more
> meaningful than just i/j would be more clear?

Ok.

>
>> + if (!(fmc2->cs_assigned & BIT(i)))
>> + continue;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, j);
>> + fmc2->data_base[i] = devm_ioremap_resource(dev, res);
>> + if (IS_ERR(fmc2->data_base[i]))
>> + return PTR_ERR(fmc2->data_base[i]);
>> +
>> + fmc2->data_phys_addr[i] = res->start;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, j + 1);
>> + fmc2->cmd_base[i] = devm_ioremap_resource(dev, res);
>> + if (IS_ERR(fmc2->cmd_base[i]))
>> + return PTR_ERR(fmc2->cmd_base[i]);
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, j + 2);
>> + fmc2->addr_base[i] = devm_ioremap_resource(dev, res);
>> + if (IS_ERR(fmc2->addr_base[i]))
>> + return PTR_ERR(fmc2->addr_base[i]);
>> + }
>> +
>> + irq = platform_get_irq(pdev, 0);
>> + ret = devm_request_irq(dev, irq, stm32_fmc2_irq, 0,
>> + dev_name(dev), fmc2);
>> + if (ret) {
>> + dev_err(dev, "failed to request irq\n");
>> + return ret;
>> + }
>> +
>> + init_completion(&fmc2->complete);
>> +
>> + fmc2->clk = devm_clk_get(dev, NULL);
>> + if (IS_ERR(fmc2->clk))
>> + return PTR_ERR(fmc2->clk);
>> +
>> + ret = clk_prepare_enable(fmc2->clk);
>> + if (ret) {
>> + dev_err(dev, "can not enable the clock\n");
>> + return ret;
>> + }
>> +
>> + rstc = devm_reset_control_get(dev, NULL);
>> + if (!IS_ERR(rstc)) {
>> + reset_control_assert(rstc);
>> + reset_control_deassert(rstc);
>> + }
>> +
>> + fmc2->dev = dev;
>> + mtd = nand_to_mtd(&fmc2->chip);
>> + chip = &fmc2->chip;
>> + nand_set_controller_data(chip, fmc2);
>> + mtd->dev.parent = dev;
>> +
>> + chip->exec_op = stm32_fmc2_exec_op;
>> + chip->select_chip = stm32_fmc2_select_chip;
>> + chip->options |= NAND_BUSWIDTH_AUTO | NAND_NO_SUBPAGE_WRITE;
>> +
>> + /* FMC2 init routine */
>> + stm32_fmc2_init(fmc2);
>> + if (timings_def)
>> + stm32_fmc2_timings_init(fmc2);
>
> You already implement ->setup_data_interface, why do you need this
> stm32_fmc2_timings_init()?

"st,fmc2-timings" is an optional property that allow the end user to
overwrite the timings calculated by setup_data_interface callback. In
case this property is defined in the device tree, timings are directly
set and stm32_fmc2_setup_interface() will be never called.

>
>> + else
>> + chip->setup_data_interface = stm32_fmc2_setup_interface;
>> +
>> + /* Default settings */
>> + chip->ecc.mode = NAND_ECC_HW;
>> + chip->ecc.size = FMC2_ECC_STEP_SIZE;
>> + chip->ecc.strength = FMC2_ECC_BCH8;
>> +
>> + /* Scan to find existence of the device */
>> + chip->dummy_controller.ops = &stm32_fmc2_nand_controller_ops;
>> + ret = nand_scan(chip, fmc2->ncs);
>> + if (ret)
>> + goto err_scan;
>> +
>> + ret = mtd_device_register(mtd, NULL, 0);
>> + if (ret)
>> + goto err_device_register;
>> +
>> + platform_set_drvdata(pdev, fmc2);
>> +
>> + return 0;
>> +
>> +err_device_register:
>> + nand_cleanup(chip);
>> +
>> +err_scan:
>> + if (fmc2->dma_ecc_ch)
>> + dma_release_channel(fmc2->dma_ecc_ch);
>> + if (fmc2->dma_tx_ch)
>> + dma_release_channel(fmc2->dma_tx_ch);
>> + if (fmc2->dma_rx_ch)
>> + dma_release_channel(fmc2->dma_rx_ch);
>> +
>> + sg_free_table(&fmc2->dma_data_sg);
>> + sg_free_table(&fmc2->dma_ecc_sg);
>> +
>> + clk_disable_unprepare(fmc2->clk);
>> +
>> + return ret;
>> +}
>> +
>> +static int stm32_fmc2_remove(struct platform_device *pdev)
>> +{
>> + struct stm32_fmc2 *fmc2 = platform_get_drvdata(pdev);
>> +
>> + nand_release(&fmc2->chip);
>> +
>> + if (fmc2->dma_ecc_ch)
>> + dma_release_channel(fmc2->dma_ecc_ch);
>> + if (fmc2->dma_tx_ch)
>> + dma_release_channel(fmc2->dma_tx_ch);
>> + if (fmc2->dma_rx_ch)
>> + dma_release_channel(fmc2->dma_rx_ch);
>> +
>> + sg_free_table(&fmc2->dma_data_sg);
>> + sg_free_table(&fmc2->dma_ecc_sg);
>> +
>> + clk_disable_unprepare(fmc2->clk);
>> +
>> + return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int stm32_fmc2_suspend(struct device *dev)
>
> Please remove the pre-processor conditionals and add
> __maybe_unused in the suspend/resume functions definitions.

Ok.

>
>> +{
>> + struct stm32_fmc2 *fmc2 = dev_get_drvdata(dev);
>> +
>> + clk_disable_unprepare(fmc2->clk);
>> +
>> + pinctrl_pm_select_sleep_state(dev);
>> +
>> + return 0;
>> +}
>> +
>> +static int stm32_fmc2_resume(struct device *dev)
>> +{
>> + struct stm32_fmc2 *fmc2 = dev_get_drvdata(dev);
>> + int i, ret;
>> +
>> + pinctrl_pm_select_default_state(dev);
>> +
>> + ret = clk_prepare_enable(fmc2->clk);
>> + if (ret) {
>> + dev_err(dev, "can not enable the clock\n");
>> + return ret;
>> + }
>> +
>> + stm32_fmc2_init(fmc2);
>> + stm32_fmc2_timings_init(fmc2);
>> + stm32_fmc2_setup(fmc2);
>> +
>> + for (i = 0; i < fmc2->ncs; i++)
>> + nand_reset(&fmc2->chip, i);
>
> This means you have one different NAND chip wired on each CS.
>
> We could have two CS wired to the same NAND chip. Calling nand_reset
> twice would be harmless but a lost of time.

Ok, so i will call nand_reset() only once as this driver only supports
one or two CS wired connected to the same NAND chip.

>
>> +
>> + return 0;
>> +}
>> +#endif
>> +
>> +static SIMPLE_DEV_PM_OPS(stm32_fmc2_pm_ops, stm32_fmc2_suspend,
>> + stm32_fmc2_resume);
>> +
>> +static const struct of_device_id stm32_fmc2_match[] = {
>> + {.compatible = "st,stm32mp15-fmc2"},
>> + {}
>> +};
>> +MODULE_DEVICE_TABLE(of, stm32_fmc2_match);
>> +
>> +static struct platform_driver stm32_fmc2_driver = {
>> + .probe = stm32_fmc2_probe,
>> + .remove = stm32_fmc2_remove,
>> + .driver = {
>> + .name = "stm32-fmc2",
>> + .of_match_table = stm32_fmc2_match,
>> + .pm = &stm32_fmc2_pm_ops,
>> + },
>> +};
>> +module_platform_driver(stm32_fmc2_driver);
>> +
>> +MODULE_ALIAS("platform:" DRIVER_NAME);
>> +MODULE_AUTHOR("Christophe Kerello <christophe.kerello@st.com>");
>> +MODULE_DESCRIPTION("STMicroelectronics STM32 FMC2 nand driver");
>> +MODULE_LICENSE("GPL v2");
>
>
> Thanks,
> Miquèl
>

Thanks,
Christophe Kerello.

\
 
 \ /
  Last update: 2018-09-24 18:39    [W:0.219 / U:0.660 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site