237 lines
6.2 KiB
C
237 lines
6.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Renesas RZ/V2H(P) USB2PHY Port reset control driver
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*
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* Copyright (C) 2025 Renesas Electronics Corporation
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*/
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#include <linux/cleanup.h>
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#include <linux/delay.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#include <linux/reset.h>
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#include <linux/reset-controller.h>
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struct rzv2h_usb2phy_regval {
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u16 reg;
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u16 val;
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};
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struct rzv2h_usb2phy_reset_of_data {
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const struct rzv2h_usb2phy_regval *init_vals;
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unsigned int init_val_count;
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u16 reset_reg;
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u16 reset_assert_val;
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u16 reset_deassert_val;
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u16 reset_status_bits;
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u16 reset_release_val;
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u16 reset2_reg;
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u16 reset2_acquire_val;
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u16 reset2_release_val;
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};
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struct rzv2h_usb2phy_reset_priv {
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const struct rzv2h_usb2phy_reset_of_data *data;
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void __iomem *base;
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struct device *dev;
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struct reset_controller_dev rcdev;
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spinlock_t lock; /* protects register accesses */
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};
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static inline struct rzv2h_usb2phy_reset_priv
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*rzv2h_usbphy_rcdev_to_priv(struct reset_controller_dev *rcdev)
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{
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return container_of(rcdev, struct rzv2h_usb2phy_reset_priv, rcdev);
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}
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/* This function must be called only after pm_runtime_resume_and_get() has been called */
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static void rzv2h_usbphy_assert_helper(struct rzv2h_usb2phy_reset_priv *priv)
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{
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const struct rzv2h_usb2phy_reset_of_data *data = priv->data;
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scoped_guard(spinlock, &priv->lock) {
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writel(data->reset2_acquire_val, priv->base + data->reset2_reg);
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writel(data->reset_assert_val, priv->base + data->reset_reg);
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}
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usleep_range(11, 20);
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}
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static int rzv2h_usbphy_reset_assert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct rzv2h_usb2phy_reset_priv *priv = rzv2h_usbphy_rcdev_to_priv(rcdev);
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struct device *dev = priv->dev;
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int ret;
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ret = pm_runtime_resume_and_get(dev);
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if (ret) {
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dev_err(dev, "pm_runtime_resume_and_get failed\n");
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return ret;
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}
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rzv2h_usbphy_assert_helper(priv);
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pm_runtime_put(dev);
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return 0;
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}
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static int rzv2h_usbphy_reset_deassert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct rzv2h_usb2phy_reset_priv *priv = rzv2h_usbphy_rcdev_to_priv(rcdev);
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const struct rzv2h_usb2phy_reset_of_data *data = priv->data;
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struct device *dev = priv->dev;
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int ret;
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ret = pm_runtime_resume_and_get(dev);
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if (ret) {
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dev_err(dev, "pm_runtime_resume_and_get failed\n");
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return ret;
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}
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scoped_guard(spinlock, &priv->lock) {
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writel(data->reset_deassert_val, priv->base + data->reset_reg);
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writel(data->reset2_release_val, priv->base + data->reset2_reg);
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writel(data->reset_release_val, priv->base + data->reset_reg);
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}
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pm_runtime_put(dev);
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return 0;
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}
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static int rzv2h_usbphy_reset_status(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct rzv2h_usb2phy_reset_priv *priv = rzv2h_usbphy_rcdev_to_priv(rcdev);
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struct device *dev = priv->dev;
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int ret;
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u32 reg;
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ret = pm_runtime_resume_and_get(dev);
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if (ret) {
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dev_err(dev, "pm_runtime_resume_and_get failed\n");
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return ret;
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}
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reg = readl(priv->base + priv->data->reset_reg);
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pm_runtime_put(dev);
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return (reg & priv->data->reset_status_bits) == priv->data->reset_status_bits;
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}
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static const struct reset_control_ops rzv2h_usbphy_reset_ops = {
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.assert = rzv2h_usbphy_reset_assert,
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.deassert = rzv2h_usbphy_reset_deassert,
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.status = rzv2h_usbphy_reset_status,
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};
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static int rzv2h_usb2phy_reset_of_xlate(struct reset_controller_dev *rcdev,
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const struct of_phandle_args *reset_spec)
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{
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/* No special handling needed, we have only one reset line per device */
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return 0;
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}
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static int rzv2h_usb2phy_reset_probe(struct platform_device *pdev)
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{
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const struct rzv2h_usb2phy_reset_of_data *data;
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struct rzv2h_usb2phy_reset_priv *priv;
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struct device *dev = &pdev->dev;
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struct reset_control *rstc;
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int error;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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data = of_device_get_match_data(dev);
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priv->data = data;
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priv->dev = dev;
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priv->base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(priv->base))
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return PTR_ERR(priv->base);
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rstc = devm_reset_control_get_shared_deasserted(dev, NULL);
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if (IS_ERR(rstc))
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return dev_err_probe(dev, PTR_ERR(rstc),
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"failed to get deasserted reset\n");
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spin_lock_init(&priv->lock);
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error = devm_pm_runtime_enable(dev);
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if (error)
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return dev_err_probe(dev, error, "Failed to enable pm_runtime\n");
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error = pm_runtime_resume_and_get(dev);
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if (error)
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return dev_err_probe(dev, error, "pm_runtime_resume_and_get failed\n");
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for (unsigned int i = 0; i < data->init_val_count; i++)
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writel(data->init_vals[i].val, priv->base + data->init_vals[i].reg);
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/* keep usb2phy in asserted state */
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rzv2h_usbphy_assert_helper(priv);
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pm_runtime_put(dev);
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priv->rcdev.ops = &rzv2h_usbphy_reset_ops;
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priv->rcdev.of_reset_n_cells = 0;
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priv->rcdev.nr_resets = 1;
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priv->rcdev.of_xlate = rzv2h_usb2phy_reset_of_xlate;
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priv->rcdev.of_node = dev->of_node;
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priv->rcdev.dev = dev;
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return devm_reset_controller_register(dev, &priv->rcdev);
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}
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/*
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* initialization values required to prepare the PHY to receive
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* assert and deassert requests.
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*/
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static const struct rzv2h_usb2phy_regval rzv2h_init_vals[] = {
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{ .reg = 0xc10, .val = 0x67c },
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{ .reg = 0xc14, .val = 0x1f },
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{ .reg = 0x600, .val = 0x909 },
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};
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static const struct rzv2h_usb2phy_reset_of_data rzv2h_reset_of_data = {
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.init_vals = rzv2h_init_vals,
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.init_val_count = ARRAY_SIZE(rzv2h_init_vals),
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.reset_reg = 0,
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.reset_assert_val = 0x206,
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.reset_status_bits = BIT(2),
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.reset_deassert_val = 0x200,
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.reset_release_val = 0x0,
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.reset2_reg = 0xb04,
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.reset2_acquire_val = 0x303,
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.reset2_release_val = 0x3,
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};
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static const struct of_device_id rzv2h_usb2phy_reset_of_match[] = {
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{ .compatible = "renesas,r9a09g057-usb2phy-reset", .data = &rzv2h_reset_of_data },
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{ /* Sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, rzv2h_usb2phy_reset_of_match);
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static struct platform_driver rzv2h_usb2phy_reset_driver = {
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.driver = {
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.name = "rzv2h_usb2phy_reset",
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.of_match_table = rzv2h_usb2phy_reset_of_match,
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},
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.probe = rzv2h_usb2phy_reset_probe,
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};
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module_platform_driver(rzv2h_usb2phy_reset_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
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MODULE_DESCRIPTION("Renesas RZ/V2H(P) USB2PHY Control");
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