// SPDX-License-Identifier: GPL-2.0+
/*
 * Marvell Armada 37xx SoC Time Base Generator clocks
 *
 * Copyright (C) 2016 Marvell
 *
 * Gregory CLEMENT <gregory.clement@free-electrons.com>
 */

#include <linux/clk-provider.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#define NUM_TBG     4

#define TBG_CTRL0               0x4
#define TBG_CTRL1               0x8
#define TBG_CTRL7               0x20
#define TBG_CTRL8               0x30

#define TBG_DIV_MASK            0x1FF

#define TBG_A_REFDIV            0
#define TBG_B_REFDIV            16

#define TBG_A_FBDIV             2
#define TBG_B_FBDIV             18

#define TBG_A_VCODIV_SE         0
#define TBG_B_VCODIV_SE         16

#define TBG_A_VCODIV_DIFF       1
#define TBG_B_VCODIV_DIFF       17

struct tbg_def {
        char *name;
        u32 refdiv_offset;
        u32 fbdiv_offset;
        u32 vcodiv_reg;
        u32 vcodiv_offset;
};

static const struct tbg_def tbg[NUM_TBG] = {
        {"TBG-A-P", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL8, TBG_A_VCODIV_DIFF},
        {"TBG-B-P", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL8, TBG_B_VCODIV_DIFF},
        {"TBG-A-S", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL1, TBG_A_VCODIV_SE},
        {"TBG-B-S", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL1, TBG_B_VCODIV_SE},
};

static unsigned int tbg_get_mult(void __iomem *reg, const struct tbg_def *ptbg)
{
        u32 val;

        val = readl(reg + TBG_CTRL0);

        return ((val >> ptbg->fbdiv_offset) & TBG_DIV_MASK) << 2;
}

static unsigned int tbg_get_div(void __iomem *reg, const struct tbg_def *ptbg)
{
        u32 val;
        unsigned int div;

        val = readl(reg + TBG_CTRL7);

        div = (val >> ptbg->refdiv_offset) & TBG_DIV_MASK;
        if (div == 0)
                div = 1;
        val = readl(reg + ptbg->vcodiv_reg);

        div *= 1 << ((val >>  ptbg->vcodiv_offset) & TBG_DIV_MASK);

        return div;
}


static int armada_3700_tbg_clock_probe(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        struct clk_hw_onecell_data *hw_tbg_data;
        struct device *dev = &pdev->dev;
        const char *parent_name;
        struct clk *parent;
        void __iomem *reg;
        int i;

        hw_tbg_data = devm_kzalloc(&pdev->dev,
                                   struct_size(hw_tbg_data, hws, NUM_TBG),
                                   GFP_KERNEL);
        if (!hw_tbg_data)
                return -ENOMEM;
        hw_tbg_data->num = NUM_TBG;
        platform_set_drvdata(pdev, hw_tbg_data);

        parent = clk_get(dev, NULL);
        if (IS_ERR(parent)) {
                dev_err(dev, "Could get the clock parent\n");
                return -EINVAL;
        }
        parent_name = __clk_get_name(parent);
        clk_put(parent);

        reg = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(reg))
                return PTR_ERR(reg);

        for (i = 0; i < NUM_TBG; i++) {
                const char *name;
                unsigned int mult, div;

                name = tbg[i].name;
                mult = tbg_get_mult(reg, &tbg[i]);
                div = tbg_get_div(reg, &tbg[i]);
                hw_tbg_data->hws[i] = clk_hw_register_fixed_factor(NULL, name,
                                                parent_name, 0, mult, div);
                if (IS_ERR(hw_tbg_data->hws[i]))
                        dev_err(dev, "Can't register TBG clock %s\n", name);
        }

        return of_clk_add_hw_provider(np, of_clk_hw_onecell_get, hw_tbg_data);
}

static void armada_3700_tbg_clock_remove(struct platform_device *pdev)
{
        int i;
        struct clk_hw_onecell_data *hw_tbg_data = platform_get_drvdata(pdev);

        of_clk_del_provider(pdev->dev.of_node);
        for (i = 0; i < hw_tbg_data->num; i++)
                clk_hw_unregister_fixed_factor(hw_tbg_data->hws[i]);
}

static const struct of_device_id armada_3700_tbg_clock_of_match[] = {
        { .compatible = "marvell,armada-3700-tbg-clock", },
        { }
};

static struct platform_driver armada_3700_tbg_clock_driver = {
        .probe = armada_3700_tbg_clock_probe,
        .remove = armada_3700_tbg_clock_remove,
        .driver         = {
                .name   = "marvell-armada-3700-tbg-clock",
                .of_match_table = armada_3700_tbg_clock_of_match,
        },
};

builtin_platform_driver(armada_3700_tbg_clock_driver);