// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2015-2016 Reinhard Pfau <reinhard.pfau@gdsys.cc>
 */

#include <config.h>
#include <common.h>
#include <errno.h>
#include <asm/io.h>
#include <asm/arch/cpu.h>
#include <asm/arch/efuse.h>
#include <asm/arch/soc.h>
#include <asm/gpio.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/mbus.h>

#if defined(CONFIG_MVEBU_EFUSE_FAKE)
#define DRY_RUN
#else
#undef DRY_RUN
#endif

#define MBUS_EFUSE_BASE 0xF6000000
#define MBUS_EFUSE_SIZE BIT(20)

#define MVEBU_EFUSE_CONTROL (MVEBU_REGISTER(0xE4008))

enum {
        MVEBU_EFUSE_CTRL_PROGRAM_ENABLE = (1 << 31),
        MVEBU_EFUSE_LD1_SELECT          = (1 <<  6),
};

struct mvebu_hd_efuse {
        u32 bits_31_0;
        u32 bits_63_32;
        u32 bit64;
        u32 reserved0;
};

#ifndef DRY_RUN
static struct mvebu_hd_efuse *efuses =
        (struct mvebu_hd_efuse *)(MBUS_EFUSE_BASE + 0xF9000);
static u32 *ld_efuses = (void *)MBUS_EFUSE_BASE + 0xF8F00;
#else
static struct mvebu_hd_efuse efuses[EFUSE_LINE_MAX + 1];
static u32 ld_efuses[EFUSE_LD_WORDS];
#endif

static int efuse_initialised;

static struct mvebu_hd_efuse *get_efuse_line(int nr)
{
        if (nr < 0 || nr > 63 || !efuse_initialised)
                return NULL;

        return efuses + nr;
}

#ifndef DRY_RUN
static int vhv_gpio;
#endif

static int enable_efuse_program(void)
{
#ifndef DRY_RUN
        if (CONFIG_MVEBU_EFUSE_VHV_GPIO[0]) {
                if (gpio_lookup_name(CONFIG_MVEBU_EFUSE_VHV_GPIO, NULL, NULL, &vhv_gpio)) {
                        printf("Error: VHV gpio lookup failed\n");
                        return -EOPNOTSUPP;
                }
                if (gpio_request(vhv_gpio, CONFIG_MVEBU_EFUSE_VHV_GPIO)) {
                        printf("Error: VHV gpio request failed\n");
                        return -EOPNOTSUPP;
                }
                if (gpio_direction_output(vhv_gpio,
                    IS_ENABLED(CONFIG_MVEBU_EFUSE_VHV_GPIO_ACTIVE_LOW) ? 0 : 1)) {
                        printf("Error: VHV gpio enable failed\n");
                        return -EINVAL;
                }
                mdelay(5); /* Wait for the VHV power to stabilize */
        }

        setbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_CTRL_PROGRAM_ENABLE);
#endif

        return 0;
}

static void disable_efuse_program(void)
{
#ifndef DRY_RUN
        clrbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_CTRL_PROGRAM_ENABLE);

        if (CONFIG_MVEBU_EFUSE_VHV_GPIO[0]) {
                if (gpio_direction_output(vhv_gpio,
                    IS_ENABLED(CONFIG_MVEBU_EFUSE_VHV_GPIO_ACTIVE_LOW) ? 1 : 0))
                        printf("Error: VHV gpio disable failed\n");
                gpio_free(vhv_gpio);
                vhv_gpio = 0;
        }
#endif
}

static int do_prog_efuse(struct mvebu_hd_efuse *efuse,
                         struct efuse_val *new_val, u32 mask0, u32 mask1)
{
        struct efuse_val val;

        val.dwords.d[0] = readl(&efuse->bits_31_0);
        val.dwords.d[1] = readl(&efuse->bits_63_32);
        val.lock = readl(&efuse->bit64);

        if (val.lock & 1)
                return -EPERM;

        val.dwords.d[0] |= (new_val->dwords.d[0] & mask0);
        val.dwords.d[1] |= (new_val->dwords.d[1] & mask1);
        val.lock |= new_val->lock;

        writel(val.dwords.d[0], &efuse->bits_31_0);
        mdelay(1);
        writel(val.dwords.d[1], &efuse->bits_63_32);
        mdelay(1);
        writel(val.lock, &efuse->bit64);
        mdelay(5);

        return 0;
}

static int prog_efuse(int nr, struct efuse_val *new_val, u32 mask0, u32 mask1)
{
        struct mvebu_hd_efuse *efuse;
        int res = 0;

        res = mvebu_efuse_init_hw();
        if (res)
                return res;

        efuse = get_efuse_line(nr);
        if (!efuse)
                return -ENODEV;

        if (!new_val)
                return -EINVAL;

        /* only write a fuse line with lock bit */
        if (!new_val->lock)
                return -EINVAL;

        /* according to specs ECC protection bits must be 0 on write */
        if (new_val->bytes.d[7] & 0xFE)
                return -EINVAL;

        if (!new_val->dwords.d[0] && !new_val->dwords.d[1] && (mask0 | mask1))
                return 0;

        res = enable_efuse_program();
        if (res)
                return res;

        res = do_prog_efuse(efuse, new_val, mask0, mask1);

        disable_efuse_program();

        return res;
}

int mvebu_prog_ld_efuse(int ld1, u32 word, u32 val)
{
        int i, res;
        u32 line[EFUSE_LD_WORDS];

        res = mvebu_efuse_init_hw();
        if (res)
                return res;

        mvebu_read_ld_efuse(ld1, line);

        /* check if lock bit is already programmed */
        if (line[EFUSE_LD_WORDS - 1])
                return -EPERM;

        /* check if word is valid */
        if (word >= EFUSE_LD_WORDS)
                return -EINVAL;

        /* check if there is some bit for programming */
        if (val == (line[word] & val))
                return 0;

        res = enable_efuse_program();
        if (res)
                return res;

        mvebu_read_ld_efuse(ld1, line);
        line[word] |= val;

        for (i = 0; i < EFUSE_LD_WORDS; i++) {
                writel(line[i], ld_efuses + i);
                mdelay(1);
        }

        mdelay(5);

        disable_efuse_program();

        return 0;
}

int mvebu_efuse_init_hw(void)
{
        int ret;

        if (efuse_initialised)
                return 0;

        ret = mvebu_mbus_add_window_by_id(
                CPU_TARGET_SATA23_DFX, 0xA, MBUS_EFUSE_BASE, MBUS_EFUSE_SIZE);

        if (ret)
                return ret;

        efuse_initialised = 1;

        return 0;
}

int mvebu_read_efuse(int nr, struct efuse_val *val)
{
        struct mvebu_hd_efuse *efuse;
        int res;

        res = mvebu_efuse_init_hw();
        if (res)
                return res;

        efuse = get_efuse_line(nr);
        if (!efuse)
                return -ENODEV;

        if (!val)
                return -EINVAL;

        val->dwords.d[0] = readl(&efuse->bits_31_0);
        val->dwords.d[1] = readl(&efuse->bits_63_32);
        val->lock = readl(&efuse->bit64);
        return 0;
}

void mvebu_read_ld_efuse(int ld1, u32 *line)
{
        int i;

#ifndef DRY_RUN
        if (ld1)
                setbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_LD1_SELECT);
        else
                clrbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_LD1_SELECT);
#endif

        for (i = 0; i < EFUSE_LD_WORDS; i++)
                line[i] = readl(ld_efuses + i);
}

int mvebu_write_efuse(int nr, struct efuse_val *val)
{
        return prog_efuse(nr, val, ~0, ~0);
}

int mvebu_lock_efuse(int nr)
{
        struct efuse_val val = {
                .lock = 1,
        };

        return prog_efuse(nr, &val, 0, 0);
}

/*
 * wrapper funcs providing the fuse API
 *
 * we use the following mapping:
 *   "bank" ->  eFuse line
 *   "word" ->  0: bits 0-31
 *              1: bits 32-63
 *              2: bit 64 (lock)
 */

static struct efuse_val prog_val;
static int valid_prog_words;

int fuse_read(u32 bank, u32 word, u32 *val)
{
        struct efuse_val fuse_line;
        u32 ld_line[EFUSE_LD_WORDS];
        int res;

        if ((bank == EFUSE_LD0_LINE || bank == EFUSE_LD1_LINE) && word < EFUSE_LD_WORDS) {
                res = mvebu_efuse_init_hw();
                if (res)
                        return res;
                mvebu_read_ld_efuse(bank == EFUSE_LD1_LINE, ld_line);
                *val = ld_line[word];
                return 0;
        }

        if (bank < EFUSE_LINE_MIN || bank > EFUSE_LINE_MAX || word > 2)
                return -EINVAL;

        res = mvebu_read_efuse(bank, &fuse_line);
        if (res)
                return res;

        if (word < 2)
                *val = fuse_line.dwords.d[word];
        else
                *val = fuse_line.lock;

        return res;
}

int fuse_sense(u32 bank, u32 word, u32 *val)
{
        /* not supported */
        return -ENOSYS;
}

int fuse_prog(u32 bank, u32 word, u32 val)
{
        int res = 0;

        if (bank == EFUSE_LD0_LINE || bank == EFUSE_LD1_LINE)
                return mvebu_prog_ld_efuse(bank == EFUSE_LD1_LINE, word, val);

        /*
         * NOTE: Fuse line should be written as whole.
         * So how can we do that with this API?
         * For now: remember values for word == 0 and word == 1 and write the
         * whole line when word == 2.
         * This implies that we always require all 3 fuse prog cmds (one for
         * for each word) to write a single fuse line.
         * Exception is a single write to word 2 which will lock the fuse line.
         *
         * Hope that will be OK.
         */

        if (bank < EFUSE_LINE_MIN || bank > EFUSE_LINE_MAX || word > 2)
                return -EINVAL;

        if (word < 2) {
                prog_val.dwords.d[word] = val;
                valid_prog_words |= (1 << word);
        } else if ((valid_prog_words & 3) == 0 && val) {
                res = mvebu_lock_efuse(bank);
                valid_prog_words = 0;
        } else if ((valid_prog_words & 3) != 3 || !val) {
                res = -EINVAL;
        } else {
                prog_val.lock = val != 0;
                res = mvebu_write_efuse(bank, &prog_val);
                valid_prog_words = 0;
        }

        return res;
}

int fuse_override(u32 bank, u32 word, u32 val)
{
        /* not supported */
        return -ENOSYS;
}