root/drivers/clk/imx/clk-pllv2.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/err.h>

#include <asm/div64.h>

#include "clk.h"

#define to_clk_pllv2(clk) (container_of(clk, struct clk_pllv2, clk))

/* PLL Register Offsets */
#define MXC_PLL_DP_CTL                  0x00
#define MXC_PLL_DP_CONFIG               0x04
#define MXC_PLL_DP_OP                   0x08
#define MXC_PLL_DP_MFD                  0x0C
#define MXC_PLL_DP_MFN                  0x10
#define MXC_PLL_DP_MFNMINUS             0x14
#define MXC_PLL_DP_MFNPLUS              0x18
#define MXC_PLL_DP_HFS_OP               0x1C
#define MXC_PLL_DP_HFS_MFD              0x20
#define MXC_PLL_DP_HFS_MFN              0x24
#define MXC_PLL_DP_MFN_TOGC             0x28
#define MXC_PLL_DP_DESTAT               0x2c

/* PLL Register Bit definitions */
#define MXC_PLL_DP_CTL_MUL_CTRL         0x2000
#define MXC_PLL_DP_CTL_DPDCK0_2_EN      0x1000
#define MXC_PLL_DP_CTL_DPDCK0_2_OFFSET  12
#define MXC_PLL_DP_CTL_ADE              0x800
#define MXC_PLL_DP_CTL_REF_CLK_DIV      0x400
#define MXC_PLL_DP_CTL_REF_CLK_SEL_MASK (3 << 8)
#define MXC_PLL_DP_CTL_REF_CLK_SEL_OFFSET       8
#define MXC_PLL_DP_CTL_HFSM             0x80
#define MXC_PLL_DP_CTL_PRE              0x40
#define MXC_PLL_DP_CTL_UPEN             0x20
#define MXC_PLL_DP_CTL_RST              0x10
#define MXC_PLL_DP_CTL_RCP              0x8
#define MXC_PLL_DP_CTL_PLM              0x4
#define MXC_PLL_DP_CTL_BRM0             0x2
#define MXC_PLL_DP_CTL_LRF              0x1

#define MXC_PLL_DP_CONFIG_BIST          0x8
#define MXC_PLL_DP_CONFIG_SJC_CE        0x4
#define MXC_PLL_DP_CONFIG_AREN          0x2
#define MXC_PLL_DP_CONFIG_LDREQ         0x1

#define MXC_PLL_DP_OP_MFI_OFFSET        4
#define MXC_PLL_DP_OP_MFI_MASK          (0xF << 4)
#define MXC_PLL_DP_OP_PDF_OFFSET        0
#define MXC_PLL_DP_OP_PDF_MASK          0xF

#define MXC_PLL_DP_MFD_OFFSET           0
#define MXC_PLL_DP_MFD_MASK             0x07FFFFFF

#define MXC_PLL_DP_MFN_OFFSET           0x0
#define MXC_PLL_DP_MFN_MASK             0x07FFFFFF

#define MXC_PLL_DP_MFN_TOGC_TOG_DIS     (1 << 17)
#define MXC_PLL_DP_MFN_TOGC_TOG_EN      (1 << 16)
#define MXC_PLL_DP_MFN_TOGC_CNT_OFFSET  0x0
#define MXC_PLL_DP_MFN_TOGC_CNT_MASK    0xFFFF

#define MXC_PLL_DP_DESTAT_TOG_SEL       (1 << 31)
#define MXC_PLL_DP_DESTAT_MFN           0x07FFFFFF

#define MAX_DPLL_WAIT_TRIES     1000 /* 1000 * udelay(1) = 1ms */

struct clk_pllv2 {
        struct clk_hw   hw;
        void __iomem    *base;
};

static unsigned long __clk_pllv2_recalc_rate(unsigned long parent_rate,
                u32 dp_ctl, u32 dp_op, u32 dp_mfd, u32 dp_mfn)
{
        long mfi, mfn, mfd, pdf, ref_clk;
        unsigned long dbl;
        u64 temp;

        dbl = dp_ctl & MXC_PLL_DP_CTL_DPDCK0_2_EN;

        pdf = dp_op & MXC_PLL_DP_OP_PDF_MASK;
        mfi = (dp_op & MXC_PLL_DP_OP_MFI_MASK) >> MXC_PLL_DP_OP_MFI_OFFSET;
        mfi = (mfi <= 5) ? 5 : mfi;
        mfd = dp_mfd & MXC_PLL_DP_MFD_MASK;
        mfn = dp_mfn & MXC_PLL_DP_MFN_MASK;
        mfn = sign_extend32(mfn, 26);

        ref_clk = 2 * parent_rate;
        if (dbl != 0)
                ref_clk *= 2;

        ref_clk /= (pdf + 1);
        temp = (u64) ref_clk * abs(mfn);
        do_div(temp, mfd + 1);
        if (mfn < 0)
                temp = (ref_clk * mfi) - temp;
        else
                temp = (ref_clk * mfi) + temp;

        return temp;
}

static unsigned long clk_pllv2_recalc_rate(struct clk_hw *hw,
                unsigned long parent_rate)
{
        u32 dp_op, dp_mfd, dp_mfn, dp_ctl;
        void __iomem *pllbase;
        struct clk_pllv2 *pll = to_clk_pllv2(hw);

        pllbase = pll->base;

        dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL);
        dp_op = __raw_readl(pllbase + MXC_PLL_DP_OP);
        dp_mfd = __raw_readl(pllbase + MXC_PLL_DP_MFD);
        dp_mfn = __raw_readl(pllbase + MXC_PLL_DP_MFN);

        return __clk_pllv2_recalc_rate(parent_rate, dp_ctl, dp_op, dp_mfd, dp_mfn);
}

static int __clk_pllv2_set_rate(unsigned long rate, unsigned long parent_rate,
                u32 *dp_op, u32 *dp_mfd, u32 *dp_mfn)
{
        u32 reg;
        long mfi, pdf, mfn, mfd = 999999;
        u64 temp64;
        unsigned long quad_parent_rate;

        quad_parent_rate = 4 * parent_rate;
        pdf = mfi = -1;
        while (++pdf < 16 && mfi < 5)
                mfi = rate * (pdf+1) / quad_parent_rate;
        if (mfi > 15)
                return -EINVAL;
        pdf--;

        temp64 = rate * (pdf + 1) - quad_parent_rate * mfi;
        do_div(temp64, quad_parent_rate / 1000000);
        mfn = (long)temp64;

        reg = mfi << 4 | pdf;

        *dp_op = reg;
        *dp_mfd = mfd;
        *dp_mfn = mfn;

        return 0;
}

static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate,
                unsigned long parent_rate)
{
        struct clk_pllv2 *pll = to_clk_pllv2(hw);
        void __iomem *pllbase;
        u32 dp_ctl, dp_op, dp_mfd, dp_mfn;
        int ret;

        pllbase = pll->base;


        ret = __clk_pllv2_set_rate(rate, parent_rate, &dp_op, &dp_mfd, &dp_mfn);
        if (ret)
                return ret;

        dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL);
        /* use dpdck0_2 */
        __raw_writel(dp_ctl | 0x1000L, pllbase + MXC_PLL_DP_CTL);

        __raw_writel(dp_op, pllbase + MXC_PLL_DP_OP);
        __raw_writel(dp_mfd, pllbase + MXC_PLL_DP_MFD);
        __raw_writel(dp_mfn, pllbase + MXC_PLL_DP_MFN);

        return 0;
}

static int clk_pllv2_determine_rate(struct clk_hw *hw,
                                    struct clk_rate_request *req)
{
        u32 dp_op, dp_mfd, dp_mfn;
        int ret;

        ret = __clk_pllv2_set_rate(req->rate, req->best_parent_rate, &dp_op,
                                   &dp_mfd, &dp_mfn);
        if (ret) {
                req->rate = ret;

                return 0;
        }

        req->rate = __clk_pllv2_recalc_rate(req->best_parent_rate,
                                            MXC_PLL_DP_CTL_DPDCK0_2_EN, dp_op,
                                            dp_mfd, dp_mfn);

        return 0;
}

static int clk_pllv2_prepare(struct clk_hw *hw)
{
        struct clk_pllv2 *pll = to_clk_pllv2(hw);
        u32 reg;
        void __iomem *pllbase;
        int i = 0;

        pllbase = pll->base;
        reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) | MXC_PLL_DP_CTL_UPEN;
        __raw_writel(reg, pllbase + MXC_PLL_DP_CTL);

        /* Wait for lock */
        do {
                reg = __raw_readl(pllbase + MXC_PLL_DP_CTL);
                if (reg & MXC_PLL_DP_CTL_LRF)
                        break;

                udelay(1);
        } while (++i < MAX_DPLL_WAIT_TRIES);

        if (i == MAX_DPLL_WAIT_TRIES) {
                pr_err("MX5: pll locking failed\n");
                return -EINVAL;
        }

        return 0;
}

static void clk_pllv2_unprepare(struct clk_hw *hw)
{
        struct clk_pllv2 *pll = to_clk_pllv2(hw);
        u32 reg;
        void __iomem *pllbase;

        pllbase = pll->base;
        reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) & ~MXC_PLL_DP_CTL_UPEN;
        __raw_writel(reg, pllbase + MXC_PLL_DP_CTL);
}

static const struct clk_ops clk_pllv2_ops = {
        .prepare = clk_pllv2_prepare,
        .unprepare = clk_pllv2_unprepare,
        .recalc_rate = clk_pllv2_recalc_rate,
        .determine_rate = clk_pllv2_determine_rate,
        .set_rate = clk_pllv2_set_rate,
};

struct clk_hw *imx_clk_hw_pllv2(const char *name, const char *parent,
                void __iomem *base)
{
        struct clk_pllv2 *pll;
        struct clk_hw *hw;
        struct clk_init_data init;
        int ret;

        pll = kzalloc_obj(*pll);
        if (!pll)
                return ERR_PTR(-ENOMEM);

        pll->base = base;

        init.name = name;
        init.ops = &clk_pllv2_ops;
        init.flags = 0;
        init.parent_names = &parent;
        init.num_parents = 1;

        pll->hw.init = &init;
        hw = &pll->hw;

        ret = clk_hw_register(NULL, hw);
        if (ret) {
                kfree(pll);
                return ERR_PTR(ret);
        }

        return hw;
}