/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2020 Oleksandr Tymoshenko <gonzo@FreeBSD.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>

#include <dev/clk/clk.h>

#include <arm64/freescale/imx/clk/imx_clk_sscg_pll.h>

#include "clkdev_if.h"

struct imx_clk_sscg_pll_sc {
        uint32_t        offset;
};

#define WRITE4(_clk, off, val)                                          \
        CLKDEV_WRITE_4(clknode_get_device(_clk), off, val)
#define READ4(_clk, off, val)                                           \
        CLKDEV_READ_4(clknode_get_device(_clk), off, val)
#define DEVICE_LOCK(_clk)                                               \
        CLKDEV_DEVICE_LOCK(clknode_get_device(_clk))
#define DEVICE_UNLOCK(_clk)                                             \
        CLKDEV_DEVICE_UNLOCK(clknode_get_device(_clk))

#define CFG0    0x00
#define  CFG0_PLL_LOCK  (1 << 31)
#define  CFG0_PD        (1 << 7)
#define  CFG0_BYPASS2   (1 << 5)
#define  CFG0_BYPASS1   (1 << 4)
#define CFG1    0x04
#define CFG2    0x08
#define  CFG2_DIVR1_MASK        (7 << 25)
#define  CFG2_DIVR1_SHIFT       25
#define  CFG2_DIVR2_MASK        (0x3f << 19)
#define  CFG2_DIVR2_SHIFT       19
#define  CFG2_DIVF1_MASK        (0x3f << 13)
#define  CFG2_DIVF1_SHIFT       13
#define  CFG2_DIVF2_MASK        (0x3f << 7)
#define  CFG2_DIVF2_SHIFT       7
#define  CFG2_DIV_MASK          (0x3f << 1)
#define  CFG2_DIV_SHIFT         1

#if 0
#define dprintf(format, arg...)                                         \
        printf("%s:(%s)" format, __func__, clknode_get_name(clk), arg)
#else
#define dprintf(format, arg...)
#endif

static int
imx_clk_sscg_pll_init(struct clknode *clk, device_t dev)
{
        if (clknode_get_parents_num(clk) > 1) {
                device_printf(clknode_get_device(clk),
                   "error: SSCG PLL does not support more than one parent yet\n");
                return (EINVAL);
        }
        clknode_init_parent_idx(clk, 0);

        return (0);
}

static int
imx_clk_sscg_pll_set_gate(struct clknode *clk, bool enable)
{
        struct imx_clk_sscg_pll_sc *sc;
        uint32_t cfg0;
        int timeout;

        sc = clknode_get_softc(clk);

        DEVICE_LOCK(clk);
        READ4(clk, sc->offset + CFG0, &cfg0);
        if (enable)
                cfg0 &= ~(CFG0_PD);
        else
                cfg0 |= CFG0_PD;
        WRITE4(clk, sc->offset + CFG0, cfg0);

        /* Reading lock */
        if (enable) {
                for (timeout = 1000; timeout; timeout--) {
                        READ4(clk, sc->offset + CFG0, &cfg0);
                        if (cfg0 & CFG0_PLL_LOCK)
                                break;
                        DELAY(1);
                }
        }

        DEVICE_UNLOCK(clk);

        return (0);
}

static int
imx_clk_sscg_pll_recalc(struct clknode *clk, uint64_t *freq)
{
        struct imx_clk_sscg_pll_sc *sc;
        uint32_t cfg0, cfg2;
        int divr1, divr2, divf1, divf2, div;

        sc = clknode_get_softc(clk);

        DEVICE_LOCK(clk);
        READ4(clk, sc->offset + CFG0, &cfg0);
        READ4(clk, sc->offset + CFG2, &cfg2);
        DEVICE_UNLOCK(clk);

        /* PLL is bypassed */
        if (cfg0 & CFG0_BYPASS2)
                return (0);

        divr1 = (cfg2 & CFG2_DIVR1_MASK) >> CFG2_DIVR1_SHIFT;
        divr2 = (cfg2 & CFG2_DIVR2_MASK) >> CFG2_DIVR2_SHIFT;
        divf1 = (cfg2 & CFG2_DIVF1_MASK) >> CFG2_DIVF1_SHIFT;
        divf2 = (cfg2 & CFG2_DIVF2_MASK) >> CFG2_DIVF2_SHIFT;
        div = (cfg2 & CFG2_DIV_MASK) >> CFG2_DIV_SHIFT;

        if (cfg0 & CFG0_BYPASS1) {
                *freq = *freq / ((divr2 + 1) * (div + 1));
                return (0);
        }

        *freq *= 2 * (divf1 + 1) * (divf2 + 1);
        *freq /= (divr1 + 1) * (divr2 + 1) * (div + 1);

        return (0);
}

static clknode_method_t imx_clk_sscg_pll_clknode_methods[] = {
        /* Device interface */
        CLKNODEMETHOD(clknode_init,             imx_clk_sscg_pll_init),
        CLKNODEMETHOD(clknode_set_gate,         imx_clk_sscg_pll_set_gate),
        CLKNODEMETHOD(clknode_recalc_freq,      imx_clk_sscg_pll_recalc),
        CLKNODEMETHOD_END
};

DEFINE_CLASS_1(imx_clk_sscg_pll_clknode, imx_clk_sscg_pll_clknode_class,
    imx_clk_sscg_pll_clknode_methods, sizeof(struct imx_clk_sscg_pll_sc),
    clknode_class);

int
imx_clk_sscg_pll_register(struct clkdom *clkdom,
    struct imx_clk_sscg_pll_def *clkdef)
{
        struct clknode *clk;
        struct imx_clk_sscg_pll_sc *sc;

        clk = clknode_create(clkdom, &imx_clk_sscg_pll_clknode_class,
            &clkdef->clkdef);
        if (clk == NULL)
                return (1);

        sc = clknode_get_softc(clk);

        sc->offset = clkdef->offset;

        clknode_register(clkdom, clk);

        return (0);
}