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

#include <linux/clk-provider.h>
#include <linux/mfd/syscon.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#define NB_GPIO1_LATCH  0x8
#define XTAL_MODE           BIT(9)

static int armada_3700_xtal_clock_probe(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        const char *xtal_name = "xtal";
        struct device_node *parent;
        struct regmap *regmap;
        struct clk_hw *xtal_hw;
        unsigned int rate;
        u32 reg;
        int ret;

        xtal_hw = devm_kzalloc(&pdev->dev, sizeof(*xtal_hw), GFP_KERNEL);
        if (!xtal_hw)
                return -ENOMEM;

        platform_set_drvdata(pdev, xtal_hw);

        parent = np->parent;
        if (!parent) {
                dev_err(&pdev->dev, "no parent\n");
                return -ENODEV;
        }

        regmap = syscon_node_to_regmap(parent);
        if (IS_ERR(regmap)) {
                dev_err(&pdev->dev, "cannot get regmap\n");
                return PTR_ERR(regmap);
        }

        ret = regmap_read(regmap, NB_GPIO1_LATCH, &reg);
        if (ret) {
                dev_err(&pdev->dev, "cannot read from regmap\n");
                return ret;
        }

        if (reg & XTAL_MODE)
                rate = 40000000;
        else
                rate = 25000000;

        of_property_read_string_index(np, "clock-output-names", 0, &xtal_name);
        xtal_hw = clk_hw_register_fixed_rate(NULL, xtal_name, NULL, 0, rate);
        if (IS_ERR(xtal_hw))
                return PTR_ERR(xtal_hw);
        ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, xtal_hw);

        return ret;
}

static void armada_3700_xtal_clock_remove(struct platform_device *pdev)
{
        of_clk_del_provider(pdev->dev.of_node);
}

static const struct of_device_id armada_3700_xtal_clock_of_match[] = {
        { .compatible = "marvell,armada-3700-xtal-clock", },
        { }
};

static struct platform_driver armada_3700_xtal_clock_driver = {
        .probe = armada_3700_xtal_clock_probe,
        .remove = armada_3700_xtal_clock_remove,
        .driver         = {
                .name   = "marvell-armada-3700-xtal-clock",
                .of_match_table = armada_3700_xtal_clock_of_match,
        },
};

builtin_platform_driver(armada_3700_xtal_clock_driver);