// SPDX-License-Identifier: GPL-2.0-only
/*
* TWL6040 clock module driver for OMAP4 McPDM functional clock
*
* Copyright (C) 2012 Texas Instruments Inc.
* Peter Ujfalusi <peter.ujfalusi@ti.com>
*/

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/mfd/twl6040.h>
#include <linux/clk-provider.h>

struct twl6040_pdmclk {
        struct twl6040 *twl6040;
        struct device *dev;
        struct clk_hw pdmclk_hw;
        int enabled;
};

static int twl6040_pdmclk_is_prepared(struct clk_hw *hw)
{
        struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
                                                     pdmclk_hw);

        return pdmclk->enabled;
}

static int twl6040_pdmclk_reset_one_clock(struct twl6040_pdmclk *pdmclk,
                                          unsigned int reg)
{
        const u8 reset_mask = TWL6040_HPLLRST;  /* Same for HPPLL and LPPLL */
        int ret;

        ret = twl6040_set_bits(pdmclk->twl6040, reg, reset_mask);
        if (ret < 0)
                return ret;

        ret = twl6040_clear_bits(pdmclk->twl6040, reg, reset_mask);
        if (ret < 0)
                return ret;

        return 0;
}

/*
 * TWL6040A2 Phoenix Audio IC erratum #6: "PDM Clock Generation Issue At
 * Cold Temperature". This affects cold boot and deeper idle states it
 * seems. The workaround consists of resetting HPPLL and LPPLL.
 */
static int twl6040_pdmclk_quirk_reset_clocks(struct twl6040_pdmclk *pdmclk)
{
        int ret;

        ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_HPPLLCTL);
        if (ret)
                return ret;

        ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_LPPLLCTL);
        if (ret)
                return ret;

        return 0;
}

static int twl6040_pdmclk_prepare(struct clk_hw *hw)
{
        struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
                                                     pdmclk_hw);
        int ret;

        ret = twl6040_power(pdmclk->twl6040, 1);
        if (ret)
                return ret;

        ret = twl6040_pdmclk_quirk_reset_clocks(pdmclk);
        if (ret)
                goto out_err;

        pdmclk->enabled = 1;

        return 0;

out_err:
        dev_err(pdmclk->dev, "%s: error %i\n", __func__, ret);
        twl6040_power(pdmclk->twl6040, 0);

        return ret;
}

static void twl6040_pdmclk_unprepare(struct clk_hw *hw)
{
        struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
                                                     pdmclk_hw);
        int ret;

        ret = twl6040_power(pdmclk->twl6040, 0);
        if (!ret)
                pdmclk->enabled = 0;

}

static unsigned long twl6040_pdmclk_recalc_rate(struct clk_hw *hw,
                                                unsigned long parent_rate)
{
        struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
                                                     pdmclk_hw);

        return twl6040_get_sysclk(pdmclk->twl6040);
}

static const struct clk_ops twl6040_pdmclk_ops = {
        .is_prepared = twl6040_pdmclk_is_prepared,
        .prepare = twl6040_pdmclk_prepare,
        .unprepare = twl6040_pdmclk_unprepare,
        .recalc_rate = twl6040_pdmclk_recalc_rate,
};

static const struct clk_init_data twl6040_pdmclk_init = {
        .name = "pdmclk",
        .ops = &twl6040_pdmclk_ops,
        .flags = CLK_GET_RATE_NOCACHE,
};

static int twl6040_pdmclk_probe(struct platform_device *pdev)
{
        struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent);
        struct twl6040_pdmclk *clkdata;
        int ret;

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

        clkdata->dev = &pdev->dev;
        clkdata->twl6040 = twl6040;

        clkdata->pdmclk_hw.init = &twl6040_pdmclk_init;
        ret = devm_clk_hw_register(&pdev->dev, &clkdata->pdmclk_hw);
        if (ret)
                return ret;

        platform_set_drvdata(pdev, clkdata);

        return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,
                                           &clkdata->pdmclk_hw);
}

static struct platform_driver twl6040_pdmclk_driver = {
        .driver = {
                .name = "twl6040-pdmclk",
        },
        .probe = twl6040_pdmclk_probe,
};

module_platform_driver(twl6040_pdmclk_driver);

MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock");
MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
MODULE_ALIAS("platform:twl6040-pdmclk");
MODULE_LICENSE("GPL");