// SPDX-License-Identifier: GPL-2.0
/*
 * DFL device driver for Nios private feature on Intel PAC (Programmable
 * Acceleration Card) N3000
 *
 * Copyright (C) 2019-2020 Intel Corporation, Inc.
 *
 * Authors:
 *   Wu Hao <hao.wu@intel.com>
 *   Xu Yilun <yilun.xu@intel.com>
 */
#include <linux/bitfield.h>
#include <linux/dfl.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/stddef.h>
#include <linux/spi/altera.h>
#include <linux/spi/spi.h>
#include <linux/types.h>

/*
 * N3000 Nios private feature registers, named as NIOS_SPI_XX on spec.
 * NS is the abbreviation of NIOS_SPI.
 */
#define N3000_NS_PARAM                          0x8
#define N3000_NS_PARAM_SHIFT_MODE_MSK           BIT_ULL(1)
#define N3000_NS_PARAM_SHIFT_MODE_MSB           0
#define N3000_NS_PARAM_SHIFT_MODE_LSB           1
#define N3000_NS_PARAM_DATA_WIDTH               GENMASK_ULL(7, 2)
#define N3000_NS_PARAM_NUM_CS                   GENMASK_ULL(13, 8)
#define N3000_NS_PARAM_CLK_POL                  BIT_ULL(14)
#define N3000_NS_PARAM_CLK_PHASE                BIT_ULL(15)
#define N3000_NS_PARAM_PERIPHERAL_ID            GENMASK_ULL(47, 32)

#define N3000_NS_CTRL                           0x10
#define N3000_NS_CTRL_WR_DATA                   GENMASK_ULL(31, 0)
#define N3000_NS_CTRL_ADDR                      GENMASK_ULL(44, 32)
#define N3000_NS_CTRL_CMD_MSK                   GENMASK_ULL(63, 62)
#define N3000_NS_CTRL_CMD_NOP                   0
#define N3000_NS_CTRL_CMD_RD                    1
#define N3000_NS_CTRL_CMD_WR                    2

#define N3000_NS_STAT                           0x18
#define N3000_NS_STAT_RD_DATA                   GENMASK_ULL(31, 0)
#define N3000_NS_STAT_RW_VAL                    BIT_ULL(32)

/* Nios handshake registers, indirect access */
#define N3000_NIOS_INIT                         0x1000
#define N3000_NIOS_INIT_DONE                    BIT(0)
#define N3000_NIOS_INIT_START                   BIT(1)
/* Mode for retimer A, link 0, the same below */
#define N3000_NIOS_INIT_REQ_FEC_MODE_A0_MSK     GENMASK(9, 8)
#define N3000_NIOS_INIT_REQ_FEC_MODE_A1_MSK     GENMASK(11, 10)
#define N3000_NIOS_INIT_REQ_FEC_MODE_A2_MSK     GENMASK(13, 12)
#define N3000_NIOS_INIT_REQ_FEC_MODE_A3_MSK     GENMASK(15, 14)
#define N3000_NIOS_INIT_REQ_FEC_MODE_B0_MSK     GENMASK(17, 16)
#define N3000_NIOS_INIT_REQ_FEC_MODE_B1_MSK     GENMASK(19, 18)
#define N3000_NIOS_INIT_REQ_FEC_MODE_B2_MSK     GENMASK(21, 20)
#define N3000_NIOS_INIT_REQ_FEC_MODE_B3_MSK     GENMASK(23, 22)
#define N3000_NIOS_INIT_REQ_FEC_MODE_NO         0x0
#define N3000_NIOS_INIT_REQ_FEC_MODE_KR         0x1
#define N3000_NIOS_INIT_REQ_FEC_MODE_RS         0x2

#define N3000_NIOS_FW_VERSION                   0x1004
#define N3000_NIOS_FW_VERSION_PATCH             GENMASK(23, 20)
#define N3000_NIOS_FW_VERSION_MINOR             GENMASK(27, 24)
#define N3000_NIOS_FW_VERSION_MAJOR             GENMASK(31, 28)

/* The retimers we use on Intel PAC N3000 is Parkvale, abbreviated to PKVL */
#define N3000_NIOS_PKVL_A_MODE_STS              0x1020
#define N3000_NIOS_PKVL_B_MODE_STS              0x1024
#define N3000_NIOS_PKVL_MODE_STS_GROUP_MSK      GENMASK(15, 8)
#define N3000_NIOS_PKVL_MODE_STS_GROUP_OK       0x0
#define N3000_NIOS_PKVL_MODE_STS_ID_MSK         GENMASK(7, 0)
/* When GROUP MASK field == GROUP_OK  */
#define N3000_NIOS_PKVL_MODE_ID_RESET           0x0
#define N3000_NIOS_PKVL_MODE_ID_4X10G           0x1
#define N3000_NIOS_PKVL_MODE_ID_4X25G           0x2
#define N3000_NIOS_PKVL_MODE_ID_2X25G           0x3
#define N3000_NIOS_PKVL_MODE_ID_2X25G_2X10G     0x4
#define N3000_NIOS_PKVL_MODE_ID_1X25G           0x5

#define N3000_NIOS_REGBUS_RETRY_COUNT           10000   /* loop count */

#define N3000_NIOS_INIT_TIMEOUT                 10000000        /* usec */
#define N3000_NIOS_INIT_TIME_INTV               100000          /* usec */

#define N3000_NIOS_INIT_REQ_FEC_MODE_MSK_ALL    \
        (N3000_NIOS_INIT_REQ_FEC_MODE_A0_MSK |  \
         N3000_NIOS_INIT_REQ_FEC_MODE_A1_MSK |  \
         N3000_NIOS_INIT_REQ_FEC_MODE_A2_MSK |  \
         N3000_NIOS_INIT_REQ_FEC_MODE_A3_MSK |  \
         N3000_NIOS_INIT_REQ_FEC_MODE_B0_MSK |  \
         N3000_NIOS_INIT_REQ_FEC_MODE_B1_MSK |  \
         N3000_NIOS_INIT_REQ_FEC_MODE_B2_MSK |  \
         N3000_NIOS_INIT_REQ_FEC_MODE_B3_MSK)

#define N3000_NIOS_INIT_REQ_FEC_MODE_NO_ALL                     \
        (FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A0_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_NO) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A1_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_NO) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A2_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_NO) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A3_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_NO) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B0_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_NO) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B1_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_NO) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B2_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_NO) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B3_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_NO))

#define N3000_NIOS_INIT_REQ_FEC_MODE_KR_ALL                     \
        (FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A0_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_KR) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A1_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_KR) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A2_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_KR) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A3_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_KR) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B0_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_KR) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B1_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_KR) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B2_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_KR) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B3_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_KR))

#define N3000_NIOS_INIT_REQ_FEC_MODE_RS_ALL                     \
        (FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A0_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_RS) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A1_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_RS) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A2_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_RS) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_A3_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_RS) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B0_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_RS) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B1_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_RS) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B2_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_RS) |          \
         FIELD_PREP(N3000_NIOS_INIT_REQ_FEC_MODE_B3_MSK,        \
                    N3000_NIOS_INIT_REQ_FEC_MODE_RS))

struct n3000_nios {
        void __iomem *base;
        struct regmap *regmap;
        struct device *dev;
        struct platform_device *altera_spi;
};

static ssize_t nios_fw_version_show(struct device *dev,
                                    struct device_attribute *attr, char *buf)
{
        struct n3000_nios *nn = dev_get_drvdata(dev);
        unsigned int val;
        int ret;

        ret = regmap_read(nn->regmap, N3000_NIOS_FW_VERSION, &val);
        if (ret)
                return ret;

        return sysfs_emit(buf, "%x.%x.%x\n",
                          (u8)FIELD_GET(N3000_NIOS_FW_VERSION_MAJOR, val),
                          (u8)FIELD_GET(N3000_NIOS_FW_VERSION_MINOR, val),
                          (u8)FIELD_GET(N3000_NIOS_FW_VERSION_PATCH, val));
}
static DEVICE_ATTR_RO(nios_fw_version);

#define IS_MODE_STATUS_OK(mode_stat)                                    \
        (FIELD_GET(N3000_NIOS_PKVL_MODE_STS_GROUP_MSK, (mode_stat)) ==  \
         N3000_NIOS_PKVL_MODE_STS_GROUP_OK)

#define IS_RETIMER_FEC_SUPPORTED(retimer_mode)                  \
        ((retimer_mode) != N3000_NIOS_PKVL_MODE_ID_RESET &&     \
         (retimer_mode) != N3000_NIOS_PKVL_MODE_ID_4X10G)

static int get_retimer_mode(struct n3000_nios *nn, unsigned int mode_stat_reg,
                            unsigned int *retimer_mode)
{
        unsigned int val;
        int ret;

        ret = regmap_read(nn->regmap, mode_stat_reg, &val);
        if (ret)
                return ret;

        if (!IS_MODE_STATUS_OK(val))
                return -EFAULT;

        *retimer_mode = FIELD_GET(N3000_NIOS_PKVL_MODE_STS_ID_MSK, val);

        return 0;
}

static ssize_t retimer_A_mode_show(struct device *dev,
                                   struct device_attribute *attr, char *buf)
{
        struct n3000_nios *nn = dev_get_drvdata(dev);
        unsigned int mode;
        int ret;

        ret = get_retimer_mode(nn, N3000_NIOS_PKVL_A_MODE_STS, &mode);
        if (ret)
                return ret;

        return sysfs_emit(buf, "0x%x\n", mode);
}
static DEVICE_ATTR_RO(retimer_A_mode);

static ssize_t retimer_B_mode_show(struct device *dev,
                                   struct device_attribute *attr, char *buf)
{
        struct n3000_nios *nn = dev_get_drvdata(dev);
        unsigned int mode;
        int ret;

        ret = get_retimer_mode(nn, N3000_NIOS_PKVL_B_MODE_STS, &mode);
        if (ret)
                return ret;

        return sysfs_emit(buf, "0x%x\n", mode);
}
static DEVICE_ATTR_RO(retimer_B_mode);

static ssize_t fec_mode_show(struct device *dev,
                             struct device_attribute *attr, char *buf)
{
        unsigned int val, retimer_a_mode, retimer_b_mode, fec_modes;
        struct n3000_nios *nn = dev_get_drvdata(dev);
        int ret;

        /* FEC mode setting is not supported in early FW versions */
        ret = regmap_read(nn->regmap, N3000_NIOS_FW_VERSION, &val);
        if (ret)
                return ret;

        if (FIELD_GET(N3000_NIOS_FW_VERSION_MAJOR, val) < 3)
                return sysfs_emit(buf, "not supported\n");

        /* If no 25G links, FEC mode setting is not supported either */
        ret = get_retimer_mode(nn, N3000_NIOS_PKVL_A_MODE_STS, &retimer_a_mode);
        if (ret)
                return ret;

        ret = get_retimer_mode(nn, N3000_NIOS_PKVL_B_MODE_STS, &retimer_b_mode);
        if (ret)
                return ret;

        if (!IS_RETIMER_FEC_SUPPORTED(retimer_a_mode) &&
            !IS_RETIMER_FEC_SUPPORTED(retimer_b_mode))
                return sysfs_emit(buf, "not supported\n");

        /* get the valid FEC mode for 25G links */
        ret = regmap_read(nn->regmap, N3000_NIOS_INIT, &val);
        if (ret)
                return ret;

        /*
         * FEC mode should always be the same for all links, as we set them
         * in this way.
         */
        fec_modes = (val & N3000_NIOS_INIT_REQ_FEC_MODE_MSK_ALL);
        if (fec_modes == N3000_NIOS_INIT_REQ_FEC_MODE_NO_ALL)
                return sysfs_emit(buf, "no\n");
        else if (fec_modes == N3000_NIOS_INIT_REQ_FEC_MODE_KR_ALL)
                return sysfs_emit(buf, "kr\n");
        else if (fec_modes == N3000_NIOS_INIT_REQ_FEC_MODE_RS_ALL)
                return sysfs_emit(buf, "rs\n");

        return -EFAULT;
}
static DEVICE_ATTR_RO(fec_mode);

static struct attribute *n3000_nios_attrs[] = {
        &dev_attr_nios_fw_version.attr,
        &dev_attr_retimer_A_mode.attr,
        &dev_attr_retimer_B_mode.attr,
        &dev_attr_fec_mode.attr,
        NULL,
};
ATTRIBUTE_GROUPS(n3000_nios);

static int n3000_nios_init_done_check(struct n3000_nios *nn)
{
        unsigned int val, state_a, state_b;
        struct device *dev = nn->dev;
        int ret, ret2;

        /*
         * The SPI is shared by the Nios core inside the FPGA, Nios will use
         * this SPI master to do some one time initialization after power up,
         * and then release the control to OS. The driver needs to poll on
         * INIT_DONE to see when driver could take the control.
         *
         * Please note that after Nios firmware version 3.0.0, INIT_START is
         * introduced, so driver needs to trigger START firstly and then check
         * INIT_DONE.
         */

        ret = regmap_read(nn->regmap, N3000_NIOS_FW_VERSION, &val);
        if (ret)
                return ret;

        /*
         * If Nios version register is totally uninitialized(== 0x0), then the
         * Nios firmware is missing. So host could take control of SPI master
         * safely, but initialization work for Nios is not done. To restore the
         * card, we need to reprogram a new Nios firmware via the BMC chip on
         * SPI bus. So the driver doesn't error out, it continues to create the
         * spi controller device and spi_board_info for BMC.
         */
        if (val == 0) {
                dev_err(dev, "Nios version reg = 0x%x, skip INIT_DONE check, but the retimer may be uninitialized\n",
                        val);
                return 0;
        }

        if (FIELD_GET(N3000_NIOS_FW_VERSION_MAJOR, val) >= 3) {
                /* read NIOS_INIT to check if retimer initialization is done */
                ret = regmap_read(nn->regmap, N3000_NIOS_INIT, &val);
                if (ret)
                        return ret;

                /* check if retimers are initialized already */
                if (val & (N3000_NIOS_INIT_DONE | N3000_NIOS_INIT_START))
                        goto nios_init_done;

                /* configure FEC mode per module param */
                val = N3000_NIOS_INIT_START;

                /*
                 * When the retimer is to be set to 10G mode, there is no FEC
                 * mode setting, so the REQ_FEC_MODE field will be ignored by
                 * Nios firmware in this case. But we should still fill the FEC
                 * mode field cause host could not get the retimer working mode
                 * until the Nios init is done.
                 *
                 * For now the driver doesn't support the retimer FEC mode
                 * switching per user's request. It is always set to Reed
                 * Solomon FEC.
                 *
                 * The driver will set the same FEC mode for all links.
                 */
                val |= N3000_NIOS_INIT_REQ_FEC_MODE_RS_ALL;

                ret = regmap_write(nn->regmap, N3000_NIOS_INIT, val);
                if (ret)
                        return ret;
        }

nios_init_done:
        /* polls on NIOS_INIT_DONE */
        ret = regmap_read_poll_timeout(nn->regmap, N3000_NIOS_INIT, val,
                                       val & N3000_NIOS_INIT_DONE,
                                       N3000_NIOS_INIT_TIME_INTV,
                                       N3000_NIOS_INIT_TIMEOUT);
        if (ret)
                dev_err(dev, "NIOS_INIT_DONE %s\n",
                        (ret == -ETIMEDOUT) ? "timed out" : "check error");

        ret2 = regmap_read(nn->regmap, N3000_NIOS_PKVL_A_MODE_STS, &state_a);
        if (ret2)
                return ret2;

        ret2 = regmap_read(nn->regmap, N3000_NIOS_PKVL_B_MODE_STS, &state_b);
        if (ret2)
                return ret2;

        if (!ret) {
                /*
                 * After INIT_DONE is detected, it still needs to check if the
                 * Nios firmware reports any error during the retimer
                 * configuration.
                 */
                if (IS_MODE_STATUS_OK(state_a) && IS_MODE_STATUS_OK(state_b))
                        return 0;

                /*
                 * If the retimer configuration is failed, the Nios firmware
                 * will still release the spi controller for host to
                 * communicate with the BMC. It makes possible for people to
                 * reprogram a new Nios firmware and restore the card. So the
                 * driver doesn't error out, it continues to create the spi
                 * controller device and spi_board_info for BMC.
                 */
                dev_err(dev, "NIOS_INIT_DONE OK, but err on retimer init\n");
        }

        dev_err(nn->dev, "PKVL_A_MODE_STS 0x%x\n", state_a);
        dev_err(nn->dev, "PKVL_B_MODE_STS 0x%x\n", state_b);

        return ret;
}

static struct spi_board_info m10_n3000_info = {
        .modalias = "m10-n3000",
        .max_speed_hz = 12500000,
        .bus_num = 0,
        .chip_select = 0,
};

static int create_altera_spi_controller(struct n3000_nios *nn)
{
        struct altera_spi_platform_data pdata = { 0 };
        struct platform_device_info pdevinfo = { 0 };
        void __iomem *base = nn->base;
        u64 v;

        v = readq(base + N3000_NS_PARAM);

        pdata.mode_bits = SPI_CS_HIGH;
        if (FIELD_GET(N3000_NS_PARAM_CLK_POL, v))
                pdata.mode_bits |= SPI_CPOL;
        if (FIELD_GET(N3000_NS_PARAM_CLK_PHASE, v))
                pdata.mode_bits |= SPI_CPHA;

        pdata.num_chipselect = FIELD_GET(N3000_NS_PARAM_NUM_CS, v);
        pdata.bits_per_word_mask =
                SPI_BPW_RANGE_MASK(1, FIELD_GET(N3000_NS_PARAM_DATA_WIDTH, v));

        pdata.num_devices = 1;
        pdata.devices = &m10_n3000_info;

        dev_dbg(nn->dev, "%s cs %u bpm 0x%x mode 0x%x\n", __func__,
                pdata.num_chipselect, pdata.bits_per_word_mask,
                pdata.mode_bits);

        pdevinfo.name = "subdev_spi_altera";
        pdevinfo.id = PLATFORM_DEVID_AUTO;
        pdevinfo.parent = nn->dev;
        pdevinfo.data = &pdata;
        pdevinfo.size_data = sizeof(pdata);

        nn->altera_spi = platform_device_register_full(&pdevinfo);
        return PTR_ERR_OR_ZERO(nn->altera_spi);
}

static void destroy_altera_spi_controller(struct n3000_nios *nn)
{
        platform_device_unregister(nn->altera_spi);
}

static int n3000_nios_poll_stat_timeout(void __iomem *base, u64 *v)
{
        int loops;

        /*
         * We don't use the time based timeout here for performance.
         *
         * The regbus read/write is on the critical path of Intel PAC N3000
         * image programming. The time based timeout checking will add too much
         * overhead on it. Usually the state changes in 1 or 2 loops on the
         * test server, and we set 10000 times loop here for safety.
         */
        for (loops = N3000_NIOS_REGBUS_RETRY_COUNT; loops > 0 ; loops--) {
                *v = readq(base + N3000_NS_STAT);
                if (*v & N3000_NS_STAT_RW_VAL)
                        break;
                cpu_relax();
        }

        return (loops > 0) ? 0 : -ETIMEDOUT;
}

static int n3000_nios_reg_write(void *context, unsigned int reg, unsigned int val)
{
        struct n3000_nios *nn = context;
        u64 v;
        int ret;

        v = FIELD_PREP(N3000_NS_CTRL_CMD_MSK, N3000_NS_CTRL_CMD_WR) |
            FIELD_PREP(N3000_NS_CTRL_ADDR, reg) |
            FIELD_PREP(N3000_NS_CTRL_WR_DATA, val);
        writeq(v, nn->base + N3000_NS_CTRL);

        ret = n3000_nios_poll_stat_timeout(nn->base, &v);
        if (ret)
                dev_err(nn->dev, "fail to write reg 0x%x val 0x%x: %d\n",
                        reg, val, ret);

        return ret;
}

static int n3000_nios_reg_read(void *context, unsigned int reg, unsigned int *val)
{
        struct n3000_nios *nn = context;
        u64 v;
        int ret;

        v = FIELD_PREP(N3000_NS_CTRL_CMD_MSK, N3000_NS_CTRL_CMD_RD) |
            FIELD_PREP(N3000_NS_CTRL_ADDR, reg);
        writeq(v, nn->base + N3000_NS_CTRL);

        ret = n3000_nios_poll_stat_timeout(nn->base, &v);
        if (ret)
                dev_err(nn->dev, "fail to read reg 0x%x: %d\n", reg, ret);
        else
                *val = FIELD_GET(N3000_NS_STAT_RD_DATA, v);

        return ret;
}

static const struct regmap_config n3000_nios_regbus_cfg = {
        .reg_bits = 32,
        .reg_stride = 4,
        .val_bits = 32,
        .fast_io = true,

        .reg_write = n3000_nios_reg_write,
        .reg_read = n3000_nios_reg_read,
};

static int n3000_nios_probe(struct dfl_device *ddev)
{
        struct device *dev = &ddev->dev;
        struct n3000_nios *nn;
        int ret;

        nn = devm_kzalloc(dev, sizeof(*nn), GFP_KERNEL);
        if (!nn)
                return -ENOMEM;

        dev_set_drvdata(&ddev->dev, nn);

        nn->dev = dev;

        nn->base = devm_ioremap_resource(&ddev->dev, &ddev->mmio_res);
        if (IS_ERR(nn->base))
                return PTR_ERR(nn->base);

        nn->regmap = devm_regmap_init(dev, NULL, nn, &n3000_nios_regbus_cfg);
        if (IS_ERR(nn->regmap))
                return PTR_ERR(nn->regmap);

        ret = n3000_nios_init_done_check(nn);
        if (ret)
                return ret;

        ret = create_altera_spi_controller(nn);
        if (ret)
                dev_err(dev, "altera spi controller create failed: %d\n", ret);

        return ret;
}

static void n3000_nios_remove(struct dfl_device *ddev)
{
        struct n3000_nios *nn = dev_get_drvdata(&ddev->dev);

        destroy_altera_spi_controller(nn);
}

#define FME_FEATURE_ID_N3000_NIOS       0xd

static const struct dfl_device_id n3000_nios_ids[] = {
        { FME_ID, FME_FEATURE_ID_N3000_NIOS },
        { }
};
MODULE_DEVICE_TABLE(dfl, n3000_nios_ids);

static struct dfl_driver n3000_nios_driver = {
        .drv    = {
                .name       = "dfl-n3000-nios",
                .dev_groups = n3000_nios_groups,
        },
        .id_table = n3000_nios_ids,
        .probe   = n3000_nios_probe,
        .remove  = n3000_nios_remove,
};

module_dfl_driver(n3000_nios_driver);

MODULE_DESCRIPTION("Driver for Nios private feature on Intel PAC N3000");
MODULE_AUTHOR("Intel Corporation");
MODULE_LICENSE("GPL v2");