Re: [RESENDPATCH v15 2/2] mtd: rawnand: Add NAND controller support on Intel LGM SoC

From: Ramuthevar, Vadivel MuruganX
Date: Thu Oct 29 2020 - 23:20:22 EST

Hi Miquel,

Thank you very much for the review comments...

On 28/10/2020 6:20 pm, Miquel Raynal wrote:
Hello,

"Ramuthevar,Vadivel MuruganX"
<vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> wrote on Mon, 26 Oct 2020
15:30:21 +0800:

From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>

This patch adds the new IP of Nand Flash Controller(NFC) support
on Intel's Lightning Mountain(LGM) SoC.

DMA is used for burst data transfer operation, also DMA HW supports
aligned 32bit memory address and aligned data access by default.
DMA burst of 8 supported. Data register used to support the read/write
operation from/to device.

NAND controller driver implements ->exec_op() to replace legacy hooks,
these specific call-back method to execute NAND operations.

No need to mention legacy hooks here as they are not part of your
driver at all.
Ok, Noted.


Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
---
drivers/mtd/nand/raw/Kconfig | 8 +
drivers/mtd/nand/raw/Makefile | 1 +
drivers/mtd/nand/raw/intel-nand-controller.c | 734 +++++++++++++++++++++++++++
3 files changed, 743 insertions(+)
create mode 100644 drivers/mtd/nand/raw/intel-nand-controller.c

diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index 6c46f25b57e2..1b3690fd08dc 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -462,6 +462,14 @@ config MTD_NAND_ARASAN
Enables the driver for the Arasan NAND flash controller on
Zynq Ultrascale+ MPSoC.
+config MTD_NAND_INTEL_LGM
+ tristate "Support for NAND controller on Intel LGM SoC"
+ depends on OF || COMPILE_TEST
+ depends on HAS_IOMEM
+ help
+ Enables support for NAND Flash chips on Intel's LGM SoC.
+ NAND flash controller interfaced through the External Bus Unit.
+
comment "Misc"
config MTD_SM_COMMON
diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
index 2930f5b9015d..9e6037363fc6 100644
--- a/drivers/mtd/nand/raw/Makefile
+++ b/drivers/mtd/nand/raw/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_MTD_NAND_STM32_FMC2) += stm32_fmc2_nand.o
obj-$(CONFIG_MTD_NAND_MESON) += meson_nand.o
obj-$(CONFIG_MTD_NAND_CADENCE) += cadence-nand-controller.o
obj-$(CONFIG_MTD_NAND_ARASAN) += arasan-nand-controller.o
+obj-$(CONFIG_MTD_NAND_INTEL_LGM) += intel-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/intel-nand-controller.c b/drivers/mtd/nand/raw/intel-nand-controller.c
new file mode 100644
index 000000000000..0aefc441c7d5
--- /dev/null
+++ b/drivers/mtd/nand/raw/intel-nand-controller.c
@@ -0,0 +1,734 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (c) 2020 Intel Corporation. */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/nand.h>
+
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <asm/unaligned.h>
+
+#define EBU_CLC 0x000
+#define EBU_CLC_RST 0x00000000u
+
+#define EBU_ADDR_SEL(n) (0x020 + (n) * 4)
+/* 5 bits 26:22 included for comparison in the ADDR_SELx */
+#define EBU_ADDR_MASK(x) ((x) << 4)
+#define EBU_ADDR_SEL_REGEN 0x1
+
+#define EBU_BUSCON(n) (0x060 + (n) * 4)
+#define EBU_BUSCON_CMULT_V4 0x1
+#define EBU_BUSCON_RECOVC(n) ((n) << 2)
+#define EBU_BUSCON_HOLDC(n) ((n) << 4)
+#define EBU_BUSCON_WAITRDC(n) ((n) << 6)
+#define EBU_BUSCON_WAITWRC(n) ((n) << 8)
+#define EBU_BUSCON_BCGEN_CS 0x0
+#define EBU_BUSCON_SETUP_EN BIT(22)
+#define EBU_BUSCON_ALEC 0xC000
+
+#define EBU_CON 0x0B0
+#define EBU_CON_NANDM_EN BIT(0)
+#define EBU_CON_NANDM_DIS 0x0
+#define EBU_CON_CSMUX_E_EN BIT(1)
+#define EBU_CON_ALE_P_LOW BIT(2)
+#define EBU_CON_CLE_P_LOW BIT(3)
+#define EBU_CON_CS_P_LOW BIT(4)
+#define EBU_CON_SE_P_LOW BIT(5)
+#define EBU_CON_WP_P_LOW BIT(6)
+#define EBU_CON_PRE_P_LOW BIT(7)
+#define EBU_CON_IN_CS_S(n) ((n) << 8)
+#define EBU_CON_OUT_CS_S(n) ((n) << 10)
+#define EBU_CON_LAT_EN_CS_P ((0x3D) << 18)
+
+#define EBU_WAIT 0x0B4
+#define EBU_WAIT_RDBY BIT(0)
+#define EBU_WAIT_WR_C BIT(3)
+
+#define HSNAND_CTL1 0x110
+#define HSNAND_CTL1_ADDR_SHIFT 24
+
+#define HSNAND_CTL2 0x114
+#define HSNAND_CTL2_ADDR_SHIFT 8
+#define HSNAND_CTL2_CYC_N_V5 (0x2 << 16)
+
+#define HSNAND_INT_MSK_CTL 0x124
+#define HSNAND_INT_MSK_CTL_WR_C BIT(4)
+
+#define HSNAND_INT_STA 0x128
+#define HSNAND_INT_STA_WR_C BIT(4)
+
+#define HSNAND_CTL 0x130
+#define HSNAND_CTL_ENABLE_ECC BIT(0)
+#define HSNAND_CTL_GO BIT(2)
+#define HSNAND_CTL_CE_SEL_CS(n) BIT(3 + (n))
+#define HSNAND_CTL_RW_READ 0x0
+#define HSNAND_CTL_RW_WRITE BIT(10)
+#define HSNAND_CTL_ECC_OFF_V8TH BIT(11)
+#define HSNAND_CTL_CKFF_EN 0x0
+#define HSNAND_CTL_MSG_EN BIT(17)
+
+#define HSNAND_PARA0 0x13c
+#define HSNAND_PARA0_PAGE_V8192 0x3
+#define HSNAND_PARA0_PIB_V256 (0x3 << 4)
+#define HSNAND_PARA0_BYP_EN_NP 0x0
+#define HSNAND_PARA0_BYP_DEC_NP 0x0
+#define HSNAND_PARA0_TYPE_ONFI BIT(18)
+#define HSNAND_PARA0_ADEP_EN BIT(21)
+
+#define HSNAND_CMSG_0 0x150
+#define HSNAND_CMSG_1 0x154
+
+#define HSNAND_ALE_OFFS BIT(2)
+#define HSNAND_CLE_OFFS BIT(3)
+#define HSNAND_CS_OFFS BIT(4)
+
+#define HSNAND_ECC_OFFSET 0x008
+
+#define NAND_DATA_IFACE_CHECK_ONLY -1
+
+#define MAX_CS 2
+
+#define HZ_PER_MHZ 1000000L
+#define USEC_PER_SEC 1000000L
+
+struct ebu_nand_cs {
+ void __iomem *chipaddr;
+ dma_addr_t nand_pa;
+ u32 addr_sel;
+};
+
+struct ebu_nand_controller {
+ struct nand_controller controller;
+ struct nand_chip chip;
+ struct device *dev;
+ void __iomem *ebu;
+ void __iomem *hsnand;
+ struct dma_chan *dma_tx;
+ struct dma_chan *dma_rx;
+ struct completion dma_access_complete;
+ unsigned long clk_rate;
+ struct clk *clk;
+ u32 nd_para0;
+ u8 cs_num;
+ struct ebu_nand_cs cs[MAX_CS];
+};
+
+static inline struct ebu_nand_controller *nand_to_ebu(struct nand_chip *chip)
+{
+ return container_of(chip, struct ebu_nand_controller, chip);
+}
+
+static int ebu_nand_waitrdy(struct nand_chip *chip, unsigned int time_out)

Please mention the unit somewhere.Sure, will update

+{
+ struct ebu_nand_controller *ctrl = nand_to_ebu(chip);
+ u32 status;
+
+ return readl_poll_timeout(ctrl->ebu + EBU_WAIT, status,
+ (status & EBU_WAIT_RDBY) ||
+ (status & EBU_WAIT_WR_C), 20, time_out);
+}
+
+static u8 ebu_nand_readb(struct nand_chip *chip)
+{
+ struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
+ u8 cs_num = ebu_host->cs_num;
+ u8 val;
+
+ val = readb(ebu_host->cs[cs_num].chipaddr + HSNAND_CS_OFFS);
+ ebu_nand_waitrdy(chip, 1000);
+ return val;
+}
+
+static void ebu_nand_writeb(struct nand_chip *chip, u32 offset, u8 value)
+{
+ struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
+ u8 cs_num = ebu_host->cs_num;
+
+ writeb(value, ebu_host->cs[cs_num].chipaddr + offset);
+ ebu_nand_waitrdy(chip, 1000);
+}
+
+static void ebu_read_buf(struct nand_chip *chip, u_char *buf, unsigned int len)
+{
+ int i;
+
+ for (i = 0; i < len; i++)
+ buf[i] = ebu_nand_readb(chip);
+}
+
+static void ebu_write_buf(struct nand_chip *chip, const u_char *buf, int len)
+{
+ int i;
+
+ for (i = 0; i < len; i++)
+ ebu_nand_writeb(chip, HSNAND_CS_OFFS, buf[i]);
+}
+
+static void ebu_nand_disable(struct nand_chip *chip)
+{
+ struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
+
+ writel(0, ebu_host->ebu + EBU_CON);
+}
+
+static void ebu_select_chip(struct nand_chip *chip)
+{
+ struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
+ void __iomem *nand_con = ebu_host->ebu + EBU_CON;
+ u32 cs = ebu_host->cs_num;
+
+ writel(EBU_CON_NANDM_EN | EBU_CON_CSMUX_E_EN | EBU_CON_CS_P_LOW |
+ EBU_CON_SE_P_LOW | EBU_CON_WP_P_LOW | EBU_CON_PRE_P_LOW |
+ EBU_CON_IN_CS_S(cs) | EBU_CON_OUT_CS_S(cs) |
+ EBU_CON_LAT_EN_CS_P, nand_con);
+}
+
+static void ebu_nand_setup_timing(struct ebu_nand_controller *ctrl,
+ const struct nand_sdr_timings *timings)
+{
+ unsigned int rate = clk_get_rate(ctrl->clk) / HZ_PER_MHZ;
+ unsigned int period = DIV_ROUND_UP(USEC_PER_SEC, rate);
+ u32 trecov, thold, twrwait, trdwait;
+ u32 reg = 0;
+
+ trecov = DIV_ROUND_UP(max(timings->tREA_max, timings->tREH_min),
+ period);
+ reg |= EBU_BUSCON_RECOVC(trecov);
+
+ thold = DIV_ROUND_UP(max(timings->tDH_min, timings->tDS_min), period);
+ reg |= EBU_BUSCON_HOLDC(thold);
+
+ trdwait = DIV_ROUND_UP(max(timings->tRC_min, timings->tREH_min),
+ period);
+ reg |= EBU_BUSCON_WAITRDC(trdwait);
+
+ twrwait = DIV_ROUND_UP(max(timings->tWC_min, timings->tWH_min), period);
+ reg |= EBU_BUSCON_WAITWRC(twrwait);
+
+ reg |= EBU_BUSCON_CMULT_V4 | EBU_BUSCON_BCGEN_CS | EBU_BUSCON_ALEC |
+ EBU_BUSCON_SETUP_EN;
+
+ writel(reg, ctrl->ebu + EBU_BUSCON(ctrl->cs_num));
+}
+
+static int ebu_nand_set_timings(struct nand_chip *chip, int csline,
+ const struct nand_interface_config *conf)
+{
+ struct ebu_nand_controller *ctrl = nand_to_ebu(chip);
+ const struct nand_sdr_timings *timings;
+
+ timings = nand_get_sdr_timings(conf);
+ if (IS_ERR(timings))
+ return PTR_ERR(timings);
+
+ if (csline == NAND_DATA_IFACE_CHECK_ONLY)
+ return 0;
+
+ ebu_nand_setup_timing(ctrl, timings);

I don't think adding this helper helps much. You could insert the code
from this function here directly?
Yes, You're right, earlier we added directely, the during the code adaptation exec_op() changed, will update it as per your suggestions

+
+ return 0;
+}
+
+static int ebu_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
+ struct mtd_oob_region *oobregion)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+
+ if (section)
+ return -ERANGE;
+
+ oobregion->offset = HSNAND_ECC_OFFSET;
+ oobregion->length = chip->ecc.total;
+
+ return 0;
+}
+
+static int ebu_nand_ooblayout_free(struct mtd_info *mtd, int section,
+ struct mtd_oob_region *oobregion)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+
+ if (section)
+ return -ERANGE;
+
+ oobregion->offset = chip->ecc.total + HSNAND_ECC_OFFSET;
+ oobregion->length = mtd->oobsize - oobregion->offset;
+
+ return 0;
+}
+
+static const struct mtd_ooblayout_ops ebu_nand_ooblayout_ops = {
+ .ecc = ebu_nand_ooblayout_ecc,
+ .free = ebu_nand_ooblayout_free,
+};
+
+static void ebu_dma_rx_callback(void *cookie)
+{
+ struct ebu_nand_controller *ebu_host = cookie;
+
+ dmaengine_terminate_async(ebu_host->dma_rx);
+
+ complete(&ebu_host->dma_access_complete);
+}
+
+static void ebu_dma_tx_callback(void *cookie)
+{
+ struct ebu_nand_controller *ebu_host = cookie;
+
+ dmaengine_terminate_async(ebu_host->dma_tx);
+
+ complete(&ebu_host->dma_access_complete);

Please check return codes when they are relevant, and return the
errors. Also treat them below.
Noted.

+}
+
+static int ebu_dma_start(struct ebu_nand_controller *ebu_host, u32 dir,
+ const u8 *buf, u32 len)
+{
+ struct dma_async_tx_descriptor *tx;
+ struct completion *dma_completion;
+ dma_async_tx_callback callback;
+ struct dma_chan *chan;
+ dma_cookie_t cookie;
+ unsigned long flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
+ dma_addr_t buf_dma;
+ int ret;
+ u32 timeout;
+
+ if (dir == DMA_DEV_TO_MEM) {
+ chan = ebu_host->dma_rx;
+ dma_completion = &ebu_host->dma_access_complete;
+ callback = ebu_dma_rx_callback;
+ } else {
+ chan = ebu_host->dma_tx;
+ dma_completion = &ebu_host->dma_access_complete;
+ callback = ebu_dma_tx_callback;
+ }
+
+ buf_dma = dma_map_single(chan->device->dev, (void *)buf, len, dir);
+ if (dma_mapping_error(chan->device->dev, buf_dma)) {
+ dev_err(ebu_host->dev, "Failed to map DMA buffer\n");
+ ret = -EIO;
+ goto err_unmap;
+ }
+
+ tx = dmaengine_prep_slave_single(chan, buf_dma, len, dir, flags);
+ if (!tx)
+ return -ENXIO;
+
+ tx->callback = callback;
+ tx->callback_param = ebu_host;
+ cookie = tx->tx_submit(tx);
+
+ ret = dma_submit_error(cookie);
+ if (ret) {
+ dev_err(ebu_host->dev, "dma_submit_error %d\n", cookie);
+ ret = -EIO;
+ goto err_unmap;
+ }
+
+ init_completion(dma_completion);
+ dma_async_issue_pending(chan);
+
+ /* Wait DMA to finish the data transfer.*/
+ timeout = wait_for_completion_timeout(dma_completion, msecs_to_jiffies(1000));
+ if (!timeout) {
+ dev_err(ebu_host->dev, "I/O Error in DMA RX (status %d)\n",
+ dmaengine_tx_status(chan, cookie, NULL));
+ dmaengine_terminate_sync(chan);
+ ret = -ETIMEDOUT;
+ goto err_unmap;
+ }
+
+ return 0;
+
+err_unmap:
+ dma_unmap_single(ebu_host->dev, buf_dma, len, dir);
+
+ return ret;
+}
+
+static void ebu_nand_trigger(struct ebu_nand_controller *ebu_host,
+ int page, u32 cmd)
+{
+ unsigned int val;
+
+ val = cmd | (page & 0xFF) << HSNAND_CTL1_ADDR_SHIFT;
+ writel(val, ebu_host->hsnand + HSNAND_CTL1);
+ val = (page & 0xFFFF00) >> 8 | HSNAND_CTL2_CYC_N_V5;
+ writel(val, ebu_host->hsnand + HSNAND_CTL2);
+
+ writel(ebu_host->nd_para0, ebu_host->hsnand + HSNAND_PARA0);
+
+ /* clear first, will update later */
+ writel(0xFFFFFFFF, ebu_host->hsnand + HSNAND_CMSG_0);
+ writel(0xFFFFFFFF, ebu_host->hsnand + HSNAND_CMSG_1);
+
+ writel(HSNAND_INT_MSK_CTL_WR_C,
+ ebu_host->hsnand + HSNAND_INT_MSK_CTL);
+
+ if (!cmd)
+ val = HSNAND_CTL_RW_READ;
+ else
+ val = HSNAND_CTL_RW_WRITE;
+
+ writel(HSNAND_CTL_MSG_EN | HSNAND_CTL_CKFF_EN |
+ HSNAND_CTL_ECC_OFF_V8TH | HSNAND_CTL_CE_SEL_CS(ebu_host->cs_num) |
+ HSNAND_CTL_ENABLE_ECC | HSNAND_CTL_GO | val,
+ ebu_host->hsnand + HSNAND_CTL);
+}
+
+static int ebu_nand_read_page_hwecc(struct nand_chip *chip, u8 *buf,
+ int oob_required, int page)
+{
+ struct mtd_info *mtd = nand_to_mtd(chip);
+ struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
+ int ret, reg_data;
+
+ ebu_nand_trigger(ebu_host, page, NAND_CMD_READ0);
+
+ ret = ebu_dma_start(ebu_host, DMA_DEV_TO_MEM, buf, mtd->writesize);
+ if (ret)
+ return ret;
+
+ if (oob_required)
+ chip->ecc.read_oob(chip, page);
+
+ reg_data = readl(ebu_host->hsnand + HSNAND_CTL);
+ reg_data &= ~HSNAND_CTL_GO;
+ writel(reg_data, ebu_host->hsnand + HSNAND_CTL);
+
+ return 0;
+}
+
+static int ebu_nand_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
+ int oob_required, int page)
+{
+ struct mtd_info *mtd = nand_to_mtd(chip);
+ struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
+ void __iomem *int_sta = ebu_host->hsnand + HSNAND_INT_STA;
+ int reg_data, ret, val;
+ u32 reg;
+
+ ebu_nand_trigger(ebu_host, page, NAND_CMD_SEQIN);
+
+ ret = ebu_dma_start(ebu_host, DMA_MEM_TO_DEV, buf, mtd->writesize);
+ if (ret)
+ return ret;
+
+ if (oob_required) {
+ reg = get_unaligned_le32(chip->oob_poi);
+ writel(reg, ebu_host->hsnand + HSNAND_CMSG_0);
+
+ reg = get_unaligned_le32(chip->oob_poi + 4);
+ writel(reg, ebu_host->hsnand + HSNAND_CMSG_1);
+ }
+
+ ret = readl_poll_timeout_atomic(int_sta, val, !(val & HSNAND_INT_STA_WR_C),
+ 10, 1000);
+ if (ret)
+ return ret;
+
+ reg_data = readl(ebu_host->hsnand + HSNAND_CTL);
+ reg_data &= ~HSNAND_CTL_GO;
+ writel(reg_data, ebu_host->hsnand + HSNAND_CTL);
+
+ return 0;
+}
+
+static const u8 ecc_strength[] = { 1, 1, 4, 8, 24, 32, 40, 60, };
+
+static int ebu_nand_attach_chip(struct nand_chip *chip)
+{
+ struct mtd_info *mtd = nand_to_mtd(chip);
+ struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
+ u32 ecc_steps, ecc_bytes, ecc_total, pagesize, pg_per_blk;
+ u32 ecc_strength_ds = chip->ecc.strength;
+ u32 ecc_size = chip->ecc.size;
+ u32 writesize = mtd->writesize;
+ u32 blocksize = mtd->erasesize;
+ int bch_algo, start, val;
+
+ /* Default to an ECC size of 512 */
+ if (!chip->ecc.size)
+ chip->ecc.size = 512;
+
+ switch (ecc_size) {
+ case 512:
+ start = 1;
+ if (!ecc_strength_ds)
+ ecc_strength_ds = 4;
+ break;
+ case 1024:
+ start = 4;
+ if (!ecc_strength_ds)
+ ecc_strength_ds = 32;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* BCH ECC algorithm Settings for number of bits per 512B/1024B */
+ bch_algo = round_up(start + 1, 4);
+ for (val = start; val < bch_algo; val++) {
+ if (ecc_strength_ds == ecc_strength[val])
+ break;
+ }
+ if (val == bch_algo)
+ return -EINVAL;
+
+ if (ecc_strength_ds == 8)
+ ecc_bytes = 14;
+ else
+ ecc_bytes = DIV_ROUND_UP(ecc_strength_ds * fls(8 * ecc_size), 8);
+
+ ecc_steps = writesize / ecc_size;
+ ecc_total = ecc_steps * ecc_bytes;
+ if ((ecc_total + 8) > mtd->oobsize)
+ return -ERANGE;
+
+ chip->ecc.total = ecc_total;
+ pagesize = fls(writesize >> 11);
+ if (pagesize > HSNAND_PARA0_PAGE_V8192)
+ return -ERANGE;
+
+ pg_per_blk = fls((blocksize / writesize) >> 6) / 8;
+ if (pg_per_blk > HSNAND_PARA0_PIB_V256)
+ return -ERANGE;
+
+ ebu_host->nd_para0 = pagesize | pg_per_blk | HSNAND_PARA0_BYP_EN_NP |
+ HSNAND_PARA0_BYP_DEC_NP | HSNAND_PARA0_ADEP_EN |
+ HSNAND_PARA0_TYPE_ONFI | (val << 29);
+
+ mtd_set_ooblayout(mtd, &ebu_nand_ooblayout_ops);
+ chip->ecc.read_page = ebu_nand_read_page_hwecc;
+ chip->ecc.write_page = ebu_nand_write_page_hwecc;
+
+ return 0;
+}
+
+static int ebu_nand_exec_op(struct nand_chip *chip,
+ const struct nand_operation *op, bool check_only)
+{
+ const struct nand_op_instr *instr = NULL;
+ unsigned int op_id;
+ int i, time_out, ret = 0;
+
+ if (check_only)
+ return 0;
+
+ ebu_select_chip(chip);
+ for (op_id = 0; op_id < op->ninstrs; op_id++) {
+ instr = &op->instrs[op_id];
+
+ switch (instr->type) {
+ case NAND_OP_CMD_INSTR:
+ ebu_nand_writeb(chip, HSNAND_CLE_OFFS | HSNAND_CS_OFFS,
+ instr->ctx.cmd.opcode);
+ break;
+
+ case NAND_OP_ADDR_INSTR:
+ for (i = 0; i < instr->ctx.addr.naddrs; i++)
+ ebu_nand_writeb(chip,
+ HSNAND_ALE_OFFS | HSNAND_CS_OFFS,
+ instr->ctx.addr.addrs[i]);
+ break;
+
+ case NAND_OP_DATA_IN_INSTR:
+ ebu_read_buf(chip, instr->ctx.data.buf.in,
+ instr->ctx.data.len);
+ break;
+
+ case NAND_OP_DATA_OUT_INSTR:
+ ebu_write_buf(chip, instr->ctx.data.buf.out,
+ instr->ctx.data.len);
+ break;
+
+ case NAND_OP_WAITRDY_INSTR:
+ time_out = instr->ctx.waitrdy.timeout_ms * 1000;
+ ret = ebu_nand_waitrdy(chip, time_out);
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static const struct nand_controller_ops ebu_nand_controller_ops = {
+ .attach_chip = ebu_nand_attach_chip,
+ .setup_interface = ebu_nand_set_timings,
+ .exec_op = ebu_nand_exec_op,
+};
+
+static void ebu_dma_cleanup(struct ebu_nand_controller *ebu_host)
+{
+ if (ebu_host->dma_rx)
+ dma_release_channel(ebu_host->dma_rx);
+
+ if (ebu_host->dma_tx)
+ dma_release_channel(ebu_host->dma_tx);
+}
+
+static int ebu_nand_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ebu_nand_controller *ebu_host;
+ struct nand_chip *nand;
+ struct mtd_info *mtd;
+ struct resource *res;
+ char *resname;
+ int ret, i;
+ u32 reg;
+
+ ebu_host = devm_kzalloc(dev, sizeof(*ebu_host), GFP_KERNEL);
+ if (!ebu_host)
+ return -ENOMEM;
+
+ ebu_host->dev = dev;
+ nand_controller_init(&ebu_host->controller);
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ebunand");
+ ebu_host->ebu = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(ebu_host->ebu))
+ return PTR_ERR(ebu_host->ebu);
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hsnand");
+ ebu_host->hsnand = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(ebu_host->hsnand))
+ return PTR_ERR(ebu_host->hsnand);
+
+ ret = device_property_read_u32(dev, "nand,cs", &reg);

There is no nand,cs property. Use 'reg' instead.
Noted.

+ if (ret) {
+ dev_err(dev, "failed to get chip select: %d\n", ret);
+ return ret;
+ }
+ ebu_host->cs_num = reg;

The following for loop is weird, above you can only store a single cs
number, while below you seem to reserve serveral memory areas. Please
clarify this code.
This IP supports 2 chip select for 2 different memory regions so we used the below for loop, as per reviewers comment updated.
EBU_CS0_BASE 0xE1C0_0000 (Memory-Mapped)
EBU_CS0_IO_BASE 0x1740_0000 (FPI I/O Mapped)

EBU_CS1_BASE 0xE140_0000 (Memory-Mapped)
EBU_CS1_IO_BASE 0x17C0_0000 (FPI I/O Mapped)


+
+ for (i = 0; i < MAX_CS; i++) {
+ resname = devm_kasprintf(dev, GFP_KERNEL, "nand_cs%d", i);
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+ resname);
+ ebu_host->cs[i].chipaddr = devm_ioremap_resource(dev, res);
+ ebu_host->cs[i].nand_pa = res->start;
+ if (IS_ERR(ebu_host->cs[i].chipaddr))
+ return PTR_ERR(ebu_host->cs[i].chipaddr);
+ }
+
+ ebu_host->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(ebu_host->clk))
+ return dev_err_probe(dev, PTR_ERR(ebu_host->clk),
+ "failed to get clock\n");
+
+ ret = clk_prepare_enable(ebu_host->clk);
+ if (ret) {
+ dev_err(dev, "failed to enable clock: %d\n", ret);
+ return ret;
+ }
+ ebu_host->clk_rate = clk_get_rate(ebu_host->clk);
+
+ ebu_host->dma_tx = dma_request_chan(dev, "tx");
+ if (IS_ERR(ebu_host->dma_tx))
+ return dev_err_probe(dev, PTR_ERR(ebu_host->dma_tx),
+ "failed to request DMA tx chan!.\n");
+
+ ebu_host->dma_rx = dma_request_chan(dev, "rx");
+ if (IS_ERR(ebu_host->dma_rx))
+ return dev_err_probe(dev, PTR_ERR(ebu_host->dma_rx),
+ "failed to request DMA rx chan!.\n");
+
+ for (i = 0; i < MAX_CS; i++) {
+ resname = devm_kasprintf(dev, GFP_KERNEL, "addr_sel%d", i);
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+ resname);
+ if (!res)
+ return -EINVAL;
+ ebu_host->cs[i].addr_sel = res->start;
+ writel(ebu_host->cs[i].addr_sel | EBU_ADDR_MASK(5) |
+ EBU_ADDR_SEL_REGEN, ebu_host->ebu + EBU_ADDR_SEL(i));
+ }
+
+ nand_set_flash_node(&ebu_host->chip, dev->of_node);
+ if (!mtd->name) {
+ dev_err(ebu_host->dev, "NAND label property is mandatory\n");
+ return -EINVAL;
+ }
+
+ mtd = nand_to_mtd(&ebu_host->chip);
+ mtd->dev.parent = dev;
+ ebu_host->dev = dev;
+
+ platform_set_drvdata(pdev, ebu_host);
+ nand_set_controller_data(&ebu_host->chip, ebu_host);
+
+ nand = &ebu_host->chip;
+ nand->controller = &ebu_host->controller;
+ nand->controller->ops = &ebu_nand_controller_ops;
+
+ /* Scan to find existence of the device */
+ ret = nand_scan(&ebu_host->chip, 1);
+ if (ret)
+ goto err_cleanup_dma;
+
+ ret = mtd_device_register(mtd, NULL, 0);
+ if (ret)
+ goto err_clean_nand;
+
+ return 0;
+
+err_clean_nand:
+ nand_cleanup(&ebu_host->chip);
+err_cleanup_dma:
+ ebu_dma_cleanup(ebu_host);
+ clk_disable_unprepare(ebu_host->clk);
+
+ return ret;
+}
+
+static int ebu_nand_remove(struct platform_device *pdev)
+{
+ struct ebu_nand_controller *ebu_host = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = mtd_device_unregister(nand_to_mtd(&ebu_host->chip));
+ WARN_ON(ret);
+ nand_cleanup(&ebu_host->chip);
+ ebu_nand_disable(&ebu_host->chip);
+ ebu_dma_cleanup(ebu_host);
+ clk_disable_unprepare(ebu_host->clk);
+
+ return 0;
+}
+
+static const struct of_device_id ebu_nand_match[] = {
+ { .compatible = "intel,nand-controller", },

No version or soc in the compatible? (not mandatory).
Yes, you're right, it should be "intel,lgm-ebunand", but this same driver supports 2 dfferent SOC's , that's the reason kept as generic
"intel,nand-controller"

Best Regards
Vadivel

+ {}
+};
+MODULE_DEVICE_TABLE(of, ebu_nand_match);
+
+static struct platform_driver ebu_nand_driver = {
+ .probe = ebu_nand_probe,
+ .remove = ebu_nand_remove,
+ .driver = {
+ .name = "intel-nand-controller",
+ .of_match_table = ebu_nand_match,
+ },
+
+};
+module_platform_driver(ebu_nand_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Vadivel Murugan R <vadivel.muruganx.ramuthevar@xxxxxxxxx>");
+MODULE_DESCRIPTION("Intel's LGM External Bus NAND Controller driver");

Thanks,
Miquèl