// SPDX-License-Identifier: GPL-2.0-only
/*
 * Joshua Henderson <joshua.henderson@microchip.com>
 * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
 */
#include <linux/io.h>
#include <linux/platform_data/pic32.h>

#include "pic32mzda.h"

/* Oscillators, PLL & clocks */
#define ICLK_MASK       0x00000080
#define PLLDIV_MASK     0x00000007
#define CUROSC_MASK     0x00000007
#define PLLMUL_MASK     0x0000007F
#define PB_MASK         0x00000007
#define FRC1            0
#define FRC2            7
#define SPLL            1
#define POSC            2
#define FRC_CLK         8000000

#define PIC32_POSC_FREQ 24000000

#define OSCCON          0x0000
#define SPLLCON         0x0020
#define PB1DIV          0x0140

u32 pic32_get_sysclk(void)
{
        u32 osc_freq = 0;
        u32 pllclk;
        u32 frcdivn;
        u32 osccon;
        u32 spllcon;
        int curr_osc;

        u32 plliclk;
        u32 pllidiv;
        u32 pllodiv;
        u32 pllmult;
        u32 frcdiv;

        void __iomem *osc_base = ioremap(PIC32_BASE_OSC, 0x200);

        osccon = __raw_readl(osc_base + OSCCON);
        spllcon = __raw_readl(osc_base + SPLLCON);

        plliclk = (spllcon & ICLK_MASK);
        pllidiv = ((spllcon >> 8) & PLLDIV_MASK) + 1;
        pllodiv = ((spllcon >> 24) & PLLDIV_MASK);
        pllmult = ((spllcon >> 16) & PLLMUL_MASK) + 1;
        frcdiv = ((osccon >> 24) & PLLDIV_MASK);

        pllclk = plliclk ? FRC_CLK : PIC32_POSC_FREQ;
        frcdivn = ((1 << frcdiv) + 1) + (128 * (frcdiv == 7));

        if (pllodiv < 2)
                pllodiv = 2;
        else if (pllodiv < 5)
                pllodiv = (1 << pllodiv);
        else
                pllodiv = 32;

        curr_osc = (int)((osccon >> 12) & CUROSC_MASK);

        switch (curr_osc) {
        case FRC1:
        case FRC2:
                osc_freq = FRC_CLK / frcdivn;
                break;
        case SPLL:
                osc_freq = ((pllclk / pllidiv) * pllmult) / pllodiv;
                break;
        case POSC:
                osc_freq = PIC32_POSC_FREQ;
                break;
        default:
                break;
        }

        iounmap(osc_base);

        return osc_freq;
}

u32 pic32_get_pbclk(int bus)
{
        u32 clk_freq;
        void __iomem *osc_base = ioremap(PIC32_BASE_OSC, 0x200);
        u32 pbxdiv = PB1DIV + ((bus - 1) * 0x10);
        u32 pbdiv = (__raw_readl(osc_base + pbxdiv) & PB_MASK) + 1;

        iounmap(osc_base);

        clk_freq = pic32_get_sysclk();

        return clk_freq / pbdiv;
}