root/drivers/clk/sunxi/clk-usb.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2013-2015 Emilio López
 *
 * Emilio López <emilio@elopez.com.ar>
 */

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/reset-controller.h>
#include <linux/slab.h>
#include <linux/spinlock.h>


/*
 * sunxi_usb_reset... - reset bits in usb clk registers handling
 */

struct usb_reset_data {
        void __iomem                    *reg;
        spinlock_t                      *lock;
        struct clk                      *clk;
        struct reset_controller_dev     rcdev;
};

static int sunxi_usb_reset_assert(struct reset_controller_dev *rcdev,
                              unsigned long id)
{
        struct usb_reset_data *data = container_of(rcdev,
                                                   struct usb_reset_data,
                                                   rcdev);
        unsigned long flags;
        u32 reg;

        clk_prepare_enable(data->clk);
        spin_lock_irqsave(data->lock, flags);

        reg = readl(data->reg);
        writel(reg & ~BIT(id), data->reg);

        spin_unlock_irqrestore(data->lock, flags);
        clk_disable_unprepare(data->clk);

        return 0;
}

static int sunxi_usb_reset_deassert(struct reset_controller_dev *rcdev,
                                unsigned long id)
{
        struct usb_reset_data *data = container_of(rcdev,
                                                     struct usb_reset_data,
                                                     rcdev);
        unsigned long flags;
        u32 reg;

        clk_prepare_enable(data->clk);
        spin_lock_irqsave(data->lock, flags);

        reg = readl(data->reg);
        writel(reg | BIT(id), data->reg);

        spin_unlock_irqrestore(data->lock, flags);
        clk_disable_unprepare(data->clk);

        return 0;
}

static const struct reset_control_ops sunxi_usb_reset_ops = {
        .assert         = sunxi_usb_reset_assert,
        .deassert       = sunxi_usb_reset_deassert,
};


#define SUNXI_USB_MAX_SIZE 32

struct usb_clk_data {
        u32 clk_mask;
        u32 reset_mask;
        bool reset_needs_clk;
};

/**
 * sunxi_usb_clk_setup() - Setup function for usb gate clocks
 * @node: &struct device_node for the clock
 * @data: &struct usb_clk_data for the clock
 * @lock: spinlock for the clock
 */
static void __init sunxi_usb_clk_setup(struct device_node *node,
                                       const struct usb_clk_data *data,
                                       spinlock_t *lock)
{
        struct clk_onecell_data *clk_data;
        struct usb_reset_data *reset_data;
        const char *clk_parent;
        const char *clk_name;
        void __iomem *reg;
        int qty;
        int i = 0;
        int j = 0;

        reg = of_io_request_and_map(node, 0, of_node_full_name(node));
        if (IS_ERR(reg))
                return;

        clk_parent = of_clk_get_parent_name(node, 0);
        if (!clk_parent)
                return;

        /* Worst-case size approximation and memory allocation */
        qty = find_last_bit((unsigned long *)&data->clk_mask,
                            SUNXI_USB_MAX_SIZE);

        clk_data = kmalloc_obj(struct clk_onecell_data);
        if (!clk_data)
                return;

        clk_data->clks = kzalloc_objs(struct clk *, qty + 1);
        if (!clk_data->clks) {
                kfree(clk_data);
                return;
        }

        for_each_set_bit(i, (unsigned long *)&data->clk_mask,
                         SUNXI_USB_MAX_SIZE) {
                of_property_read_string_index(node, "clock-output-names",
                                              j, &clk_name);
                clk_data->clks[i] = clk_register_gate(NULL, clk_name,
                                                      clk_parent, 0,
                                                      reg, i, 0, lock);
                WARN_ON(IS_ERR(clk_data->clks[i]));

                j++;
        }

        /* Adjust to the real max */
        clk_data->clk_num = i;

        of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);

        /* Register a reset controller for usb with reset bits */
        if (data->reset_mask == 0)
                return;

        reset_data = kzalloc_obj(*reset_data);
        if (!reset_data)
                return;

        if (data->reset_needs_clk) {
                reset_data->clk = of_clk_get(node, 0);
                if (IS_ERR(reset_data->clk)) {
                        pr_err("Could not get clock for reset controls\n");
                        kfree(reset_data);
                        return;
                }
        }

        reset_data->reg = reg;
        reset_data->lock = lock;
        reset_data->rcdev.nr_resets = __fls(data->reset_mask) + 1;
        reset_data->rcdev.ops = &sunxi_usb_reset_ops;
        reset_data->rcdev.of_node = node;
        reset_controller_register(&reset_data->rcdev);
}

static const struct usb_clk_data sun4i_a10_usb_clk_data __initconst = {
        .clk_mask = BIT(8) | BIT(7) | BIT(6),
        .reset_mask = BIT(2) | BIT(1) | BIT(0),
};

static DEFINE_SPINLOCK(sun4i_a10_usb_lock);

static void __init sun4i_a10_usb_setup(struct device_node *node)
{
        sunxi_usb_clk_setup(node, &sun4i_a10_usb_clk_data, &sun4i_a10_usb_lock);
}
CLK_OF_DECLARE(sun4i_a10_usb, "allwinner,sun4i-a10-usb-clk", sun4i_a10_usb_setup);

static const struct usb_clk_data sun5i_a13_usb_clk_data __initconst = {
        .clk_mask = BIT(8) | BIT(6),
        .reset_mask = BIT(1) | BIT(0),
};

static void __init sun5i_a13_usb_setup(struct device_node *node)
{
        sunxi_usb_clk_setup(node, &sun5i_a13_usb_clk_data, &sun4i_a10_usb_lock);
}
CLK_OF_DECLARE(sun5i_a13_usb, "allwinner,sun5i-a13-usb-clk", sun5i_a13_usb_setup);

static const struct usb_clk_data sun6i_a31_usb_clk_data __initconst = {
        .clk_mask = BIT(18) | BIT(17) | BIT(16) | BIT(10) | BIT(9) | BIT(8),
        .reset_mask = BIT(2) | BIT(1) | BIT(0),
};

static void __init sun6i_a31_usb_setup(struct device_node *node)
{
        sunxi_usb_clk_setup(node, &sun6i_a31_usb_clk_data, &sun4i_a10_usb_lock);
}
CLK_OF_DECLARE(sun6i_a31_usb, "allwinner,sun6i-a31-usb-clk", sun6i_a31_usb_setup);

static const struct usb_clk_data sun8i_a23_usb_clk_data __initconst = {
        .clk_mask = BIT(16) | BIT(11) | BIT(10) | BIT(9) | BIT(8),
        .reset_mask = BIT(2) | BIT(1) | BIT(0),
};

static void __init sun8i_a23_usb_setup(struct device_node *node)
{
        sunxi_usb_clk_setup(node, &sun8i_a23_usb_clk_data, &sun4i_a10_usb_lock);
}
CLK_OF_DECLARE(sun8i_a23_usb, "allwinner,sun8i-a23-usb-clk", sun8i_a23_usb_setup);

static const struct usb_clk_data sun8i_h3_usb_clk_data __initconst = {
        .clk_mask =  BIT(19) | BIT(18) | BIT(17) | BIT(16) |
                     BIT(11) | BIT(10) | BIT(9) | BIT(8),
        .reset_mask = BIT(3) | BIT(2) | BIT(1) | BIT(0),
};

static void __init sun8i_h3_usb_setup(struct device_node *node)
{
        sunxi_usb_clk_setup(node, &sun8i_h3_usb_clk_data, &sun4i_a10_usb_lock);
}
CLK_OF_DECLARE(sun8i_h3_usb, "allwinner,sun8i-h3-usb-clk", sun8i_h3_usb_setup);

static const struct usb_clk_data sun9i_a80_usb_mod_data __initconst = {
        .clk_mask = BIT(6) | BIT(5) | BIT(4) | BIT(3) | BIT(2) | BIT(1),
        .reset_mask = BIT(19) | BIT(18) | BIT(17),
        .reset_needs_clk = 1,
};

static DEFINE_SPINLOCK(a80_usb_mod_lock);

static void __init sun9i_a80_usb_mod_setup(struct device_node *node)
{
        sunxi_usb_clk_setup(node, &sun9i_a80_usb_mod_data, &a80_usb_mod_lock);
}
CLK_OF_DECLARE(sun9i_a80_usb_mod, "allwinner,sun9i-a80-usb-mod-clk", sun9i_a80_usb_mod_setup);

static const struct usb_clk_data sun9i_a80_usb_phy_data __initconst = {
        .clk_mask = BIT(10) | BIT(5) | BIT(4) | BIT(3) | BIT(2) | BIT(1),
        .reset_mask = BIT(21) | BIT(20) | BIT(19) | BIT(18) | BIT(17),
        .reset_needs_clk = 1,
};

static DEFINE_SPINLOCK(a80_usb_phy_lock);

static void __init sun9i_a80_usb_phy_setup(struct device_node *node)
{
        sunxi_usb_clk_setup(node, &sun9i_a80_usb_phy_data, &a80_usb_phy_lock);
}
CLK_OF_DECLARE(sun9i_a80_usb_phy, "allwinner,sun9i-a80-usb-phy-clk", sun9i_a80_usb_phy_setup);