// SPDX-License-Identifier: GPL-2.0
/*
 * Xilinx VCU Init
 *
 * Copyright (C) 2016 - 2017 Xilinx, Inc.
 *
 * Contacts   Dhaval Shah <dshah@xilinx.com>
 */
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/xlnx-vcu.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#include <dt-bindings/clock/xlnx-vcu.h>

#define VCU_PLL_CTRL                    0x24
#define VCU_PLL_CTRL_RESET              BIT(0)
#define VCU_PLL_CTRL_POR_IN             BIT(1)
#define VCU_PLL_CTRL_PWR_POR            BIT(2)
#define VCU_PLL_CTRL_BYPASS             BIT(3)
#define VCU_PLL_CTRL_FBDIV              GENMASK(14, 8)
#define VCU_PLL_CTRL_CLKOUTDIV          GENMASK(18, 16)

#define VCU_PLL_CFG                     0x28
#define VCU_PLL_CFG_RES                 GENMASK(3, 0)
#define VCU_PLL_CFG_CP                  GENMASK(8, 5)
#define VCU_PLL_CFG_LFHF                GENMASK(12, 10)
#define VCU_PLL_CFG_LOCK_CNT            GENMASK(22, 13)
#define VCU_PLL_CFG_LOCK_DLY            GENMASK(31, 25)
#define VCU_ENC_CORE_CTRL               0x30
#define VCU_ENC_MCU_CTRL                0x34
#define VCU_DEC_CORE_CTRL               0x38
#define VCU_DEC_MCU_CTRL                0x3c
#define VCU_PLL_STATUS                  0x60
#define VCU_PLL_STATUS_LOCK_STATUS      BIT(0)

#define MHZ                             1000000
#define FVCO_MIN                        (1500U * MHZ)
#define FVCO_MAX                        (3000U * MHZ)

/**
 * struct xvcu_device - Xilinx VCU init device structure
 * @dev: Platform device
 * @pll_ref: pll ref clock source
 * @aclk: axi clock source
 * @reset_gpio: vcu reset gpio
 * @logicore_reg_ba: logicore reg base address
 * @vcu_slcr_ba: vcu_slcr Register base address
 * @pll: handle for the VCU PLL
 * @pll_post: handle for the VCU PLL post divider
 * @clk_data: clocks provided by the vcu clock provider
 */
struct xvcu_device {
        struct device *dev;
        struct clk *pll_ref;
        struct clk *aclk;
        struct gpio_desc *reset_gpio;
        struct regmap *logicore_reg_ba;
        void __iomem *vcu_slcr_ba;
        struct clk_hw *pll;
        struct clk_hw *pll_post;
        struct clk_hw_onecell_data *clk_data;
};

static const struct regmap_config vcu_settings_regmap_config = {
        .name = "regmap",
        .reg_bits = 32,
        .val_bits = 32,
        .reg_stride = 4,
        .max_register = 0xfff,
        .cache_type = REGCACHE_NONE,
};

/**
 * struct xvcu_pll_cfg - Helper data
 * @fbdiv: The integer portion of the feedback divider to the PLL
 * @cp: PLL charge pump control
 * @res: PLL loop filter resistor control
 * @lfhf: PLL loop filter high frequency capacitor control
 * @lock_dly: Lock circuit configuration settings for lock windowsize
 * @lock_cnt: Lock circuit counter setting
 */
struct xvcu_pll_cfg {
        u32 fbdiv;
        u32 cp;
        u32 res;
        u32 lfhf;
        u32 lock_dly;
        u32 lock_cnt;
};

static const struct xvcu_pll_cfg xvcu_pll_cfg[] = {
        { 25, 3, 10, 3, 63, 1000 },
        { 26, 3, 10, 3, 63, 1000 },
        { 27, 4, 6, 3, 63, 1000 },
        { 28, 4, 6, 3, 63, 1000 },
        { 29, 4, 6, 3, 63, 1000 },
        { 30, 4, 6, 3, 63, 1000 },
        { 31, 6, 1, 3, 63, 1000 },
        { 32, 6, 1, 3, 63, 1000 },
        { 33, 4, 10, 3, 63, 1000 },
        { 34, 5, 6, 3, 63, 1000 },
        { 35, 5, 6, 3, 63, 1000 },
        { 36, 5, 6, 3, 63, 1000 },
        { 37, 5, 6, 3, 63, 1000 },
        { 38, 5, 6, 3, 63, 975 },
        { 39, 3, 12, 3, 63, 950 },
        { 40, 3, 12, 3, 63, 925 },
        { 41, 3, 12, 3, 63, 900 },
        { 42, 3, 12, 3, 63, 875 },
        { 43, 3, 12, 3, 63, 850 },
        { 44, 3, 12, 3, 63, 850 },
        { 45, 3, 12, 3, 63, 825 },
        { 46, 3, 12, 3, 63, 800 },
        { 47, 3, 12, 3, 63, 775 },
        { 48, 3, 12, 3, 63, 775 },
        { 49, 3, 12, 3, 63, 750 },
        { 50, 3, 12, 3, 63, 750 },
        { 51, 3, 2, 3, 63, 725 },
        { 52, 3, 2, 3, 63, 700 },
        { 53, 3, 2, 3, 63, 700 },
        { 54, 3, 2, 3, 63, 675 },
        { 55, 3, 2, 3, 63, 675 },
        { 56, 3, 2, 3, 63, 650 },
        { 57, 3, 2, 3, 63, 650 },
        { 58, 3, 2, 3, 63, 625 },
        { 59, 3, 2, 3, 63, 625 },
        { 60, 3, 2, 3, 63, 625 },
        { 61, 3, 2, 3, 63, 600 },
        { 62, 3, 2, 3, 63, 600 },
        { 63, 3, 2, 3, 63, 600 },
        { 64, 3, 2, 3, 63, 600 },
        { 65, 3, 2, 3, 63, 600 },
        { 66, 3, 2, 3, 63, 600 },
        { 67, 3, 2, 3, 63, 600 },
        { 68, 3, 2, 3, 63, 600 },
        { 69, 3, 2, 3, 63, 600 },
        { 70, 3, 2, 3, 63, 600 },
        { 71, 3, 2, 3, 63, 600 },
        { 72, 3, 2, 3, 63, 600 },
        { 73, 3, 2, 3, 63, 600 },
        { 74, 3, 2, 3, 63, 600 },
        { 75, 3, 2, 3, 63, 600 },
        { 76, 3, 2, 3, 63, 600 },
        { 77, 3, 2, 3, 63, 600 },
        { 78, 3, 2, 3, 63, 600 },
        { 79, 3, 2, 3, 63, 600 },
        { 80, 3, 2, 3, 63, 600 },
        { 81, 3, 2, 3, 63, 600 },
        { 82, 3, 2, 3, 63, 600 },
        { 83, 4, 2, 3, 63, 600 },
        { 84, 4, 2, 3, 63, 600 },
        { 85, 4, 2, 3, 63, 600 },
        { 86, 4, 2, 3, 63, 600 },
        { 87, 4, 2, 3, 63, 600 },
        { 88, 4, 2, 3, 63, 600 },
        { 89, 4, 2, 3, 63, 600 },
        { 90, 4, 2, 3, 63, 600 },
        { 91, 4, 2, 3, 63, 600 },
        { 92, 4, 2, 3, 63, 600 },
        { 93, 4, 2, 3, 63, 600 },
        { 94, 4, 2, 3, 63, 600 },
        { 95, 4, 2, 3, 63, 600 },
        { 96, 4, 2, 3, 63, 600 },
        { 97, 4, 2, 3, 63, 600 },
        { 98, 4, 2, 3, 63, 600 },
        { 99, 4, 2, 3, 63, 600 },
        { 100, 4, 2, 3, 63, 600 },
        { 101, 4, 2, 3, 63, 600 },
        { 102, 4, 2, 3, 63, 600 },
        { 103, 5, 2, 3, 63, 600 },
        { 104, 5, 2, 3, 63, 600 },
        { 105, 5, 2, 3, 63, 600 },
        { 106, 5, 2, 3, 63, 600 },
        { 107, 3, 4, 3, 63, 600 },
        { 108, 3, 4, 3, 63, 600 },
        { 109, 3, 4, 3, 63, 600 },
        { 110, 3, 4, 3, 63, 600 },
        { 111, 3, 4, 3, 63, 600 },
        { 112, 3, 4, 3, 63, 600 },
        { 113, 3, 4, 3, 63, 600 },
        { 114, 3, 4, 3, 63, 600 },
        { 115, 3, 4, 3, 63, 600 },
        { 116, 3, 4, 3, 63, 600 },
        { 117, 3, 4, 3, 63, 600 },
        { 118, 3, 4, 3, 63, 600 },
        { 119, 3, 4, 3, 63, 600 },
        { 120, 3, 4, 3, 63, 600 },
        { 121, 3, 4, 3, 63, 600 },
        { 122, 3, 4, 3, 63, 600 },
        { 123, 3, 4, 3, 63, 600 },
        { 124, 3, 4, 3, 63, 600 },
        { 125, 3, 4, 3, 63, 600 },
};

/**
 * xvcu_read - Read from the VCU register space
 * @iomem:      vcu reg space base address
 * @offset:     vcu reg offset from base
 *
 * Return:      Returns 32bit value from VCU register specified
 *
 */
static inline u32 xvcu_read(void __iomem *iomem, u32 offset)
{
        return ioread32(iomem + offset);
}

/**
 * xvcu_write - Write to the VCU register space
 * @iomem:      vcu reg space base address
 * @offset:     vcu reg offset from base
 * @value:      Value to write
 */
static inline void xvcu_write(void __iomem *iomem, u32 offset, u32 value)
{
        iowrite32(value, iomem + offset);
}

#define to_vcu_pll(_hw) container_of(_hw, struct vcu_pll, hw)

struct vcu_pll {
        struct clk_hw hw;
        void __iomem *reg_base;
        unsigned long fvco_min;
        unsigned long fvco_max;
};

static int xvcu_pll_wait_for_lock(struct vcu_pll *pll)
{
        void __iomem *base = pll->reg_base;
        unsigned long timeout;
        u32 lock_status;

        timeout = jiffies + msecs_to_jiffies(2000);
        do {
                lock_status = xvcu_read(base, VCU_PLL_STATUS);
                if (lock_status & VCU_PLL_STATUS_LOCK_STATUS)
                        return 0;
        } while (!time_after(jiffies, timeout));

        return -ETIMEDOUT;
}

static struct clk_hw *xvcu_register_pll_post(struct device *dev,
                                             const char *name,
                                             const struct clk_hw *parent_hw,
                                             void __iomem *reg_base)
{
        u32 div;
        u32 vcu_pll_ctrl;

        /*
         * The output divider of the PLL must be set to 1/2 to meet the
         * timing in the design.
         */
        vcu_pll_ctrl = xvcu_read(reg_base, VCU_PLL_CTRL);
        div = FIELD_GET(VCU_PLL_CTRL_CLKOUTDIV, vcu_pll_ctrl);
        if (div != 1)
                return ERR_PTR(-EINVAL);

        return clk_hw_register_fixed_factor(dev, "vcu_pll_post",
                                            clk_hw_get_name(parent_hw),
                                            CLK_SET_RATE_PARENT, 1, 2);
}

static const struct xvcu_pll_cfg *xvcu_find_cfg(int div)
{
        const struct xvcu_pll_cfg *cfg = NULL;
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(xvcu_pll_cfg) - 1; i++)
                if (xvcu_pll_cfg[i].fbdiv == div)
                        cfg = &xvcu_pll_cfg[i];

        return cfg;
}

static int xvcu_pll_set_div(struct vcu_pll *pll, int div)
{
        void __iomem *base = pll->reg_base;
        const struct xvcu_pll_cfg *cfg = NULL;
        u32 vcu_pll_ctrl;
        u32 cfg_val;

        cfg = xvcu_find_cfg(div);
        if (!cfg)
                return -EINVAL;

        vcu_pll_ctrl = xvcu_read(base, VCU_PLL_CTRL);
        vcu_pll_ctrl &= ~VCU_PLL_CTRL_FBDIV;
        vcu_pll_ctrl |= FIELD_PREP(VCU_PLL_CTRL_FBDIV, cfg->fbdiv);
        xvcu_write(base, VCU_PLL_CTRL, vcu_pll_ctrl);

        cfg_val = FIELD_PREP(VCU_PLL_CFG_RES, cfg->res) |
                  FIELD_PREP(VCU_PLL_CFG_CP, cfg->cp) |
                  FIELD_PREP(VCU_PLL_CFG_LFHF, cfg->lfhf) |
                  FIELD_PREP(VCU_PLL_CFG_LOCK_CNT, cfg->lock_cnt) |
                  FIELD_PREP(VCU_PLL_CFG_LOCK_DLY, cfg->lock_dly);
        xvcu_write(base, VCU_PLL_CFG, cfg_val);

        return 0;
}

static int xvcu_pll_determine_rate(struct clk_hw *hw,
                                   struct clk_rate_request *req)
{
        struct vcu_pll *pll = to_vcu_pll(hw);
        unsigned int feedback_div;

        req->rate = clamp_t(unsigned long, req->rate, pll->fvco_min,
                            pll->fvco_max);

        feedback_div = DIV_ROUND_CLOSEST_ULL(req->rate, req->best_parent_rate);
        feedback_div = clamp_t(unsigned int, feedback_div, 25, 125);

        req->rate = req->best_parent_rate * feedback_div;

        return 0;
}

static unsigned long xvcu_pll_recalc_rate(struct clk_hw *hw,
                                          unsigned long parent_rate)
{
        struct vcu_pll *pll = to_vcu_pll(hw);
        void __iomem *base = pll->reg_base;
        unsigned int div;
        u32 vcu_pll_ctrl;

        vcu_pll_ctrl = xvcu_read(base, VCU_PLL_CTRL);
        div = FIELD_GET(VCU_PLL_CTRL_FBDIV, vcu_pll_ctrl);

        return div * parent_rate;
}

static int xvcu_pll_set_rate(struct clk_hw *hw,
                             unsigned long rate, unsigned long parent_rate)
{
        struct vcu_pll *pll = to_vcu_pll(hw);

        return xvcu_pll_set_div(pll, rate / parent_rate);
}

static int xvcu_pll_enable(struct clk_hw *hw)
{
        struct vcu_pll *pll = to_vcu_pll(hw);
        void __iomem *base = pll->reg_base;
        u32 vcu_pll_ctrl;
        int ret;

        vcu_pll_ctrl = xvcu_read(base, VCU_PLL_CTRL);
        vcu_pll_ctrl |= VCU_PLL_CTRL_BYPASS;
        xvcu_write(base, VCU_PLL_CTRL, vcu_pll_ctrl);

        vcu_pll_ctrl = xvcu_read(base, VCU_PLL_CTRL);
        vcu_pll_ctrl &= ~VCU_PLL_CTRL_POR_IN;
        vcu_pll_ctrl &= ~VCU_PLL_CTRL_PWR_POR;
        vcu_pll_ctrl &= ~VCU_PLL_CTRL_RESET;
        xvcu_write(base, VCU_PLL_CTRL, vcu_pll_ctrl);

        ret = xvcu_pll_wait_for_lock(pll);
        if (ret) {
                pr_err("VCU PLL is not locked\n");
                goto err;
        }

        vcu_pll_ctrl = xvcu_read(base, VCU_PLL_CTRL);
        vcu_pll_ctrl &= ~VCU_PLL_CTRL_BYPASS;
        xvcu_write(base, VCU_PLL_CTRL, vcu_pll_ctrl);

err:
        return ret;
}

static void xvcu_pll_disable(struct clk_hw *hw)
{
        struct vcu_pll *pll = to_vcu_pll(hw);
        void __iomem *base = pll->reg_base;
        u32 vcu_pll_ctrl;

        vcu_pll_ctrl = xvcu_read(base, VCU_PLL_CTRL);
        vcu_pll_ctrl |= VCU_PLL_CTRL_POR_IN;
        vcu_pll_ctrl |= VCU_PLL_CTRL_PWR_POR;
        vcu_pll_ctrl |= VCU_PLL_CTRL_RESET;
        xvcu_write(base, VCU_PLL_CTRL, vcu_pll_ctrl);
}

static const struct clk_ops vcu_pll_ops = {
        .enable = xvcu_pll_enable,
        .disable = xvcu_pll_disable,
        .determine_rate = xvcu_pll_determine_rate,
        .recalc_rate = xvcu_pll_recalc_rate,
        .set_rate = xvcu_pll_set_rate,
};

static struct clk_hw *xvcu_register_pll(struct device *dev,
                                        void __iomem *reg_base,
                                        const char *name, const char *parent,
                                        unsigned long flags)
{
        struct vcu_pll *pll;
        struct clk_hw *hw;
        struct clk_init_data init;
        int ret;

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

        pll = devm_kmalloc(dev, sizeof(*pll), GFP_KERNEL);
        if (!pll)
                return ERR_PTR(-ENOMEM);

        pll->hw.init = &init;
        pll->reg_base = reg_base;
        pll->fvco_min = FVCO_MIN;
        pll->fvco_max = FVCO_MAX;

        hw = &pll->hw;
        ret = devm_clk_hw_register(dev, hw);
        if (ret)
                return ERR_PTR(ret);

        clk_hw_set_rate_range(hw, pll->fvco_min, pll->fvco_max);

        return hw;
}

static struct clk_hw *xvcu_clk_hw_register_leaf(struct device *dev,
                                                const char *name,
                                                const struct clk_parent_data *parent_data,
                                                u8 num_parents,
                                                void __iomem *reg)
{
        u8 mux_flags = CLK_MUX_ROUND_CLOSEST;
        u8 divider_flags = CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO |
                           CLK_DIVIDER_ROUND_CLOSEST;
        struct clk_hw *mux = NULL;
        struct clk_hw *divider = NULL;
        struct clk_hw *gate = NULL;
        char *name_mux;
        char *name_div;
        int err;
        /* Protect register shared by clocks */
        spinlock_t *lock;

        lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
        if (!lock)
                return ERR_PTR(-ENOMEM);
        spin_lock_init(lock);

        name_mux = devm_kasprintf(dev, GFP_KERNEL, "%s%s", name, "_mux");
        if (!name_mux)
                return ERR_PTR(-ENOMEM);
        mux = clk_hw_register_mux_parent_data(dev, name_mux,
                                              parent_data, num_parents,
                                              CLK_SET_RATE_PARENT,
                                              reg, 0, 1, mux_flags, lock);
        if (IS_ERR(mux))
                return mux;

        name_div = devm_kasprintf(dev, GFP_KERNEL, "%s%s", name, "_div");
        if (!name_div) {
                err = -ENOMEM;
                goto unregister_mux;
        }
        divider = clk_hw_register_divider_parent_hw(dev, name_div, mux,
                                                    CLK_SET_RATE_PARENT,
                                                    reg, 4, 6, divider_flags,
                                                    lock);
        if (IS_ERR(divider)) {
                err = PTR_ERR(divider);
                goto unregister_mux;
        }

        gate = clk_hw_register_gate_parent_hw(dev, name, divider,
                                              CLK_SET_RATE_PARENT, reg, 12, 0,
                                              lock);
        if (IS_ERR(gate)) {
                err = PTR_ERR(gate);
                goto unregister_divider;
        }

        return gate;

unregister_divider:
        clk_hw_unregister_divider(divider);
unregister_mux:
        clk_hw_unregister_mux(mux);

        return ERR_PTR(err);
}

static void xvcu_clk_hw_unregister_leaf(struct clk_hw *hw)
{
        struct clk_hw *gate = hw;
        struct clk_hw *divider;
        struct clk_hw *mux;

        if (!gate)
                return;

        divider = clk_hw_get_parent(gate);
        clk_hw_unregister_gate(gate);
        if (!divider)
                return;

        mux = clk_hw_get_parent(divider);
        clk_hw_unregister_mux(mux);
        if (!divider)
                return;

        clk_hw_unregister_divider(divider);
}

static int xvcu_register_clock_provider(struct xvcu_device *xvcu)
{
        struct device *dev = xvcu->dev;
        struct clk_parent_data parent_data[2] = { 0 };
        struct clk_hw_onecell_data *data;
        struct clk_hw **hws;
        struct clk_hw *hw;
        void __iomem *reg_base = xvcu->vcu_slcr_ba;

        data = devm_kzalloc(dev, struct_size(data, hws, CLK_XVCU_NUM_CLOCKS), GFP_KERNEL);
        if (!data)
                return -ENOMEM;
        data->num = CLK_XVCU_NUM_CLOCKS;
        hws = data->hws;

        xvcu->clk_data = data;

        hw = xvcu_register_pll(dev, reg_base,
                               "vcu_pll", __clk_get_name(xvcu->pll_ref),
                               CLK_SET_RATE_NO_REPARENT | CLK_OPS_PARENT_ENABLE);
        if (IS_ERR(hw))
                return PTR_ERR(hw);
        xvcu->pll = hw;

        hw = xvcu_register_pll_post(dev, "vcu_pll_post", xvcu->pll, reg_base);
        if (IS_ERR(hw))
                return PTR_ERR(hw);
        xvcu->pll_post = hw;

        parent_data[0].fw_name = "pll_ref";
        parent_data[1].hw = xvcu->pll_post;

        hws[CLK_XVCU_ENC_CORE] =
                xvcu_clk_hw_register_leaf(dev, "venc_core_clk",
                                          parent_data,
                                          ARRAY_SIZE(parent_data),
                                          reg_base + VCU_ENC_CORE_CTRL);
        hws[CLK_XVCU_ENC_MCU] =
                xvcu_clk_hw_register_leaf(dev, "venc_mcu_clk",
                                          parent_data,
                                          ARRAY_SIZE(parent_data),
                                          reg_base + VCU_ENC_MCU_CTRL);
        hws[CLK_XVCU_DEC_CORE] =
                xvcu_clk_hw_register_leaf(dev, "vdec_core_clk",
                                          parent_data,
                                          ARRAY_SIZE(parent_data),
                                          reg_base + VCU_DEC_CORE_CTRL);
        hws[CLK_XVCU_DEC_MCU] =
                xvcu_clk_hw_register_leaf(dev, "vdec_mcu_clk",
                                          parent_data,
                                          ARRAY_SIZE(parent_data),
                                          reg_base + VCU_DEC_MCU_CTRL);

        return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, data);
}

static void xvcu_unregister_clock_provider(struct xvcu_device *xvcu)
{
        struct clk_hw_onecell_data *data = xvcu->clk_data;
        struct clk_hw **hws = data->hws;

        if (!IS_ERR_OR_NULL(hws[CLK_XVCU_DEC_MCU]))
                xvcu_clk_hw_unregister_leaf(hws[CLK_XVCU_DEC_MCU]);
        if (!IS_ERR_OR_NULL(hws[CLK_XVCU_DEC_CORE]))
                xvcu_clk_hw_unregister_leaf(hws[CLK_XVCU_DEC_CORE]);
        if (!IS_ERR_OR_NULL(hws[CLK_XVCU_ENC_MCU]))
                xvcu_clk_hw_unregister_leaf(hws[CLK_XVCU_ENC_MCU]);
        if (!IS_ERR_OR_NULL(hws[CLK_XVCU_ENC_CORE]))
                xvcu_clk_hw_unregister_leaf(hws[CLK_XVCU_ENC_CORE]);
        if (!IS_ERR_OR_NULL(xvcu->pll_post))
                clk_hw_unregister_fixed_factor(xvcu->pll_post);
}

/**
 * xvcu_probe - Probe existence of the logicoreIP
 *                      and initialize PLL
 *
 * @pdev:       Pointer to the platform_device structure
 *
 * Return:      Returns 0 on success
 *              Negative error code otherwise
 */
static int xvcu_probe(struct platform_device *pdev)
{
        struct resource *res;
        struct xvcu_device *xvcu;
        void __iomem *regs;
        int ret;

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

        xvcu->dev = &pdev->dev;
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "vcu_slcr");
        if (!res) {
                dev_err(&pdev->dev, "get vcu_slcr memory resource failed.\n");
                return -ENODEV;
        }

        xvcu->vcu_slcr_ba = devm_ioremap(&pdev->dev, res->start,
                                         resource_size(res));
        if (!xvcu->vcu_slcr_ba) {
                dev_err(&pdev->dev, "vcu_slcr register mapping failed.\n");
                return -ENOMEM;
        }

        xvcu->logicore_reg_ba =
                syscon_regmap_lookup_by_compatible("xlnx,vcu-settings");
        if (IS_ERR(xvcu->logicore_reg_ba)) {
                dev_info(&pdev->dev,
                         "could not find xlnx,vcu-settings: trying direct register access\n");

                res = platform_get_resource_byname(pdev,
                                                   IORESOURCE_MEM, "logicore");
                if (!res) {
                        dev_err(&pdev->dev, "get logicore memory resource failed.\n");
                        return -ENODEV;
                }

                regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
                if (!regs) {
                        dev_err(&pdev->dev, "logicore register mapping failed.\n");
                        return -ENOMEM;
                }

                xvcu->logicore_reg_ba =
                        devm_regmap_init_mmio(&pdev->dev, regs,
                                              &vcu_settings_regmap_config);
                if (IS_ERR(xvcu->logicore_reg_ba)) {
                        dev_err(&pdev->dev, "failed to init regmap\n");
                        return PTR_ERR(xvcu->logicore_reg_ba);
                }
        }

        xvcu->aclk = devm_clk_get(&pdev->dev, "aclk");
        if (IS_ERR(xvcu->aclk)) {
                dev_err(&pdev->dev, "Could not get aclk clock\n");
                return PTR_ERR(xvcu->aclk);
        }

        xvcu->pll_ref = devm_clk_get(&pdev->dev, "pll_ref");
        if (IS_ERR(xvcu->pll_ref)) {
                dev_err(&pdev->dev, "Could not get pll_ref clock\n");
                return PTR_ERR(xvcu->pll_ref);
        }

        ret = clk_prepare_enable(xvcu->aclk);
        if (ret) {
                dev_err(&pdev->dev, "aclk clock enable failed\n");
                return ret;
        }

        /*
         * Do the Gasket isolation and put the VCU out of reset
         * Bit 0 : Gasket isolation
         * Bit 1 : put VCU out of reset
         */
        xvcu->reset_gpio = devm_gpiod_get_optional(&pdev->dev, "reset",
                                                   GPIOD_OUT_LOW);
        if (IS_ERR(xvcu->reset_gpio)) {
                ret = PTR_ERR(xvcu->reset_gpio);
                dev_err_probe(&pdev->dev, ret, "failed to get reset gpio for vcu.\n");
                goto error_get_gpio;
        }

        if (xvcu->reset_gpio) {
                gpiod_set_value(xvcu->reset_gpio, 0);
                /* min 2 clock cycle of vcu pll_ref, slowest freq is 33.33KHz */
                usleep_range(60, 120);
                gpiod_set_value(xvcu->reset_gpio, 1);
                usleep_range(60, 120);
        } else {
                dev_dbg(&pdev->dev, "No reset gpio info found in dts for VCU. This may result in incorrect functionality if VCU isolation is removed after initialization in designs where the VCU reset is driven by gpio.\n");
        }

        regmap_write(xvcu->logicore_reg_ba, VCU_GASKET_INIT, VCU_GASKET_VALUE);

        ret = xvcu_register_clock_provider(xvcu);
        if (ret) {
                dev_err(&pdev->dev, "failed to register clock provider\n");
                goto error_clk_provider;
        }

        dev_set_drvdata(&pdev->dev, xvcu);

        return 0;

error_clk_provider:
        xvcu_unregister_clock_provider(xvcu);
error_get_gpio:
        clk_disable_unprepare(xvcu->aclk);
        return ret;
}

/**
 * xvcu_remove - Insert gasket isolation
 *                      and disable the clock
 * @pdev:       Pointer to the platform_device structure
 *
 * Return:      Returns 0 on success
 *              Negative error code otherwise
 */
static void xvcu_remove(struct platform_device *pdev)
{
        struct xvcu_device *xvcu;

        xvcu = platform_get_drvdata(pdev);

        xvcu_unregister_clock_provider(xvcu);

        /* Add the Gasket isolation and put the VCU in reset. */
        if (xvcu->reset_gpio) {
                gpiod_set_value(xvcu->reset_gpio, 0);
                /* min 2 clock cycle of vcu pll_ref, slowest freq is 33.33KHz */
                usleep_range(60, 120);
                gpiod_set_value(xvcu->reset_gpio, 1);
                usleep_range(60, 120);
        }
        regmap_write(xvcu->logicore_reg_ba, VCU_GASKET_INIT, 0);

        clk_disable_unprepare(xvcu->aclk);
}

static const struct of_device_id xvcu_of_id_table[] = {
        { .compatible = "xlnx,vcu" },
        { .compatible = "xlnx,vcu-logicoreip-1.0" },
        { }
};
MODULE_DEVICE_TABLE(of, xvcu_of_id_table);

static struct platform_driver xvcu_driver = {
        .driver = {
                .name           = "xilinx-vcu",
                .of_match_table = xvcu_of_id_table,
        },
        .probe                  = xvcu_probe,
        .remove                 = xvcu_remove,
};

module_platform_driver(xvcu_driver);

MODULE_AUTHOR("Dhaval Shah <dshah@xilinx.com>");
MODULE_DESCRIPTION("Xilinx VCU init Driver");
MODULE_LICENSE("GPL v2");