root/drivers/mtd/nand/raw/intel-nand-controller.c
// 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.h>

#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/units.h>
#include <linux/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 MAX_CS  2

#define USEC_PER_SEC    1000000L

struct ebu_nand_cs {
        void __iomem *chipaddr;
        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;
        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, int timeout_ms)
{
        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, timeout_ms);
}

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 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);
        unsigned int rate = clk_get_rate(ctrl->clk) / HZ_PER_MHZ;
        unsigned int period = DIV_ROUND_UP(USEC_PER_SEC, rate);
        const struct nand_sdr_timings *timings;
        u32 trecov, thold, twrwait, trdwait;
        u32 reg = 0;

        timings = nand_get_sdr_timings(conf);
        if (IS_ERR(timings))
                return PTR_ERR(timings);

        if (csline == NAND_DATA_IFACE_CHECK_ONLY)
                return 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));

        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);
}

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;
        unsigned long time_left;

        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) {
                ret = -ENXIO;
                goto err_unmap;
        }

        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.*/
        time_left = wait_for_completion_timeout(dma_completion, msecs_to_jiffies(1000));
        if (!time_left) {
                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, timeout_ms, 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:
                        timeout_ms = instr->ctx.waitrdy.timeout_ms * 1000;
                        ret = ebu_nand_waitrdy(chip, timeout_ms);
                        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 device_node *chip_np;
        struct nand_chip *nand;
        struct mtd_info *mtd;
        struct resource *res;
        char *resname;
        int ret;
        u32 cs;

        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);

        ebu_host->ebu = devm_platform_ioremap_resource_byname(pdev, "ebunand");
        if (IS_ERR(ebu_host->ebu))
                return PTR_ERR(ebu_host->ebu);

        ebu_host->hsnand = devm_platform_ioremap_resource_byname(pdev, "hsnand");
        if (IS_ERR(ebu_host->hsnand))
                return PTR_ERR(ebu_host->hsnand);

        chip_np = of_get_next_child(dev->of_node, NULL);
        if (!chip_np)
                return dev_err_probe(dev, -EINVAL,
                                     "Could not find child node for the NAND chip\n");

        ret = of_property_read_u32(chip_np, "reg", &cs);
        if (ret) {
                dev_err(dev, "failed to get chip select: %d\n", ret);
                goto err_of_node_put;
        }
        if (cs >= MAX_CS) {
                dev_err(dev, "got invalid chip select: %d\n", cs);
                ret = -EINVAL;
                goto err_of_node_put;
        }

        ebu_host->cs_num = cs;

        resname = devm_kasprintf(dev, GFP_KERNEL, "nand_cs%d", cs);
        if (!resname) {
                ret = -ENOMEM;
                goto err_of_node_put;
        }

        ebu_host->cs[cs].chipaddr = devm_platform_ioremap_resource_byname(pdev,
                                                                          resname);
        if (IS_ERR(ebu_host->cs[cs].chipaddr)) {
                ret = PTR_ERR(ebu_host->cs[cs].chipaddr);
                goto err_of_node_put;
        }

        ebu_host->clk = devm_clk_get_enabled(dev, NULL);
        if (IS_ERR(ebu_host->clk)) {
                ret = dev_err_probe(dev, PTR_ERR(ebu_host->clk),
                                    "failed to get and enable clock\n");
                goto err_of_node_put;
        }

        ebu_host->dma_tx = dma_request_chan(dev, "tx");
        if (IS_ERR(ebu_host->dma_tx)) {
                ret = dev_err_probe(dev, PTR_ERR(ebu_host->dma_tx),
                                    "failed to request DMA tx chan!.\n");
                goto err_of_node_put;
        }

        ebu_host->dma_rx = dma_request_chan(dev, "rx");
        if (IS_ERR(ebu_host->dma_rx)) {
                ret = dev_err_probe(dev, PTR_ERR(ebu_host->dma_rx),
                                    "failed to request DMA rx chan!.\n");
                ebu_host->dma_rx = NULL;
                goto err_cleanup_dma;
        }

        resname = devm_kasprintf(dev, GFP_KERNEL, "addr_sel%d", cs);
        if (!resname) {
                ret = -ENOMEM;
                goto err_cleanup_dma;
        }

        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, resname);
        if (!res) {
                ret = -EINVAL;
                goto err_cleanup_dma;
        }
        ebu_host->cs[cs].addr_sel = res->start;
        writel(ebu_host->cs[cs].addr_sel | EBU_ADDR_MASK(5) | EBU_ADDR_SEL_REGEN,
               ebu_host->ebu + EBU_ADDR_SEL(cs));

        nand_set_flash_node(&ebu_host->chip, chip_np);

        mtd = nand_to_mtd(&ebu_host->chip);
        if (!mtd->name) {
                dev_err(ebu_host->dev, "NAND label property is mandatory\n");
                ret = -EINVAL;
                goto err_cleanup_dma;
        }

        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);
err_of_node_put:
        of_node_put(chip_np);

        return ret;
}

static void 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);
}

static const struct of_device_id ebu_nand_match[] = {
        { .compatible = "intel,lgm-ebunand" },
        {}
};
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@intel.com>");
MODULE_DESCRIPTION("Intel's LGM External Bus NAND Controller driver");