drivers/reset/reset-npcm.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 // Copyright (c) 2019 Nuvoton Technology corporation.

 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/init.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/reboot.h>
 #include <linux/reset-controller.h>
 #include <linux/spinlock.h>
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
 #include <linux/of_address.h>

 /* NPCM7xx GCR registers */
 #define NPCM_MDLR_OFFSET	0x7C
 #define NPCM7XX_MDLR_USBD0	BIT(9)
 #define NPCM7XX_MDLR_USBD1	BIT(8)
 #define NPCM7XX_MDLR_USBD2_4	BIT(21)
 #define NPCM7XX_MDLR_USBD5_9	BIT(22)

 /* NPCM8xx MDLR bits */
 #define NPCM8XX_MDLR_USBD0_3	BIT(9)
 #define NPCM8XX_MDLR_USBD4_7	BIT(22)
 #define NPCM8XX_MDLR_USBD8	BIT(24)
 #define NPCM8XX_MDLR_USBD9	BIT(21)

 #define NPCM_USB1PHYCTL_OFFSET	0x140
 #define NPCM_USB2PHYCTL_OFFSET	0x144
 #define NPCM_USB3PHYCTL_OFFSET	0x148
 #define NPCM_USBXPHYCTL_RS	BIT(28)

 /* NPCM7xx Reset registers */
 #define NPCM_SWRSTR		0x14
 #define NPCM_SWRST		BIT(2)

 #define NPCM_IPSRST1		0x20
 #define NPCM_IPSRST1_USBD1	BIT(5)
 #define NPCM_IPSRST1_USBD2	BIT(8)
 #define NPCM_IPSRST1_USBD3	BIT(25)
 #define NPCM_IPSRST1_USBD4	BIT(22)
 #define NPCM_IPSRST1_USBD5	BIT(23)
 #define NPCM_IPSRST1_USBD6	BIT(24)

 #define NPCM_IPSRST2		0x24
 #define NPCM_IPSRST2_USB_HOST	BIT(26)

 #define NPCM_IPSRST3		0x34
 #define NPCM_IPSRST3_USBD0	BIT(4)
 #define NPCM_IPSRST3_USBD7	BIT(5)
 #define NPCM_IPSRST3_USBD8	BIT(6)
 #define NPCM_IPSRST3_USBD9	BIT(7)
 #define NPCM_IPSRST3_USBPHY1	BIT(24)
 #define NPCM_IPSRST3_USBPHY2	BIT(25)

 #define NPCM_IPSRST4		0x74
 #define NPCM_IPSRST4_USBPHY3	BIT(25)
 #define NPCM_IPSRST4_USB_HOST2	BIT(31)

 #define NPCM_RC_RESETS_PER_REG	32
 #define NPCM_MASK_RESETS	GENMASK(4, 0)

 enum {
 	BMC_NPCM7XX = 0,
 	BMC_NPCM8XX,
 };

 static const u32 npxm7xx_ipsrst[] = {NPCM_IPSRST1, NPCM_IPSRST2, NPCM_IPSRST3};
 static const u32 npxm8xx_ipsrst[] = {NPCM_IPSRST1, NPCM_IPSRST2, NPCM_IPSRST3,
 	NPCM_IPSRST4};

 struct npcm_reset_info {
 	u32 bmc_id;
 	u32 num_ipsrst;
 	const u32 *ipsrst;
 };

 static const struct npcm_reset_info npxm7xx_reset_info[] = {
 	{.bmc_id = BMC_NPCM7XX, .num_ipsrst = 3, .ipsrst = npxm7xx_ipsrst}};
 static const struct npcm_reset_info npxm8xx_reset_info[] = {
 	{.bmc_id = BMC_NPCM8XX, .num_ipsrst = 4, .ipsrst = npxm8xx_ipsrst}};

 struct npcm_rc_data {
 	struct reset_controller_dev rcdev;
 	struct notifier_block restart_nb;
 	const struct npcm_reset_info *info;
 	struct regmap *gcr_regmap;
 	u32 sw_reset_number;
 	void __iomem *base;
 	spinlock_t lock;
 };

 #define to_rc_data(p) container_of(p, struct npcm_rc_data, rcdev)

 static int npcm_rc_restart(struct notifier_block *nb, unsigned long mode,
 			   void *cmd)
 {
 	struct npcm_rc_data *rc = container_of(nb, struct npcm_rc_data,
 					       restart_nb);

 	writel(NPCM_SWRST << rc->sw_reset_number, rc->base + NPCM_SWRSTR);
 	mdelay(1000);

 	pr_emerg("%s: unable to restart system\n", __func__);

 	return NOTIFY_DONE;
 }

 static int npcm_rc_setclear_reset(struct reset_controller_dev *rcdev,
 				  unsigned long id, bool set)
 {
 	struct npcm_rc_data *rc = to_rc_data(rcdev);
 	unsigned int rst_bit = BIT(id & NPCM_MASK_RESETS);
 	unsigned int ctrl_offset = id >> 8;
 	unsigned long flags;
 	u32 stat;

 	spin_lock_irqsave(&rc->lock, flags);
 	stat = readl(rc->base + ctrl_offset);
 	if (set)
 		writel(stat | rst_bit, rc->base + ctrl_offset);
 	else
 		writel(stat & ~rst_bit, rc->base + ctrl_offset);
 	spin_unlock_irqrestore(&rc->lock, flags);

 	return 0;
 }

 static int npcm_rc_assert(struct reset_controller_dev *rcdev, unsigned long id)
 {
 	return npcm_rc_setclear_reset(rcdev, id, true);
 }

 static int npcm_rc_deassert(struct reset_controller_dev *rcdev,
 			    unsigned long id)
 {
 	return npcm_rc_setclear_reset(rcdev, id, false);
 }

 static int npcm_rc_status(struct reset_controller_dev *rcdev,
 			  unsigned long id)
 {
 	struct npcm_rc_data *rc = to_rc_data(rcdev);
 	unsigned int rst_bit = BIT(id & NPCM_MASK_RESETS);
 	unsigned int ctrl_offset = id >> 8;

 	return (readl(rc->base + ctrl_offset) & rst_bit);
 }

 static int npcm_reset_xlate(struct reset_controller_dev *rcdev,
 			    const struct of_phandle_args *reset_spec)
 {
 	struct npcm_rc_data *rc = to_rc_data(rcdev);
 	unsigned int offset, bit;
 	bool offset_found = false;
 	int off_num;

 	offset = reset_spec->args[0];
 	for (off_num = 0 ; off_num < rc->info->num_ipsrst ; off_num++) {
 		if (offset == rc->info->ipsrst[off_num]) {
 			offset_found = true;
 			break;
 		}
 	}

 	if (!offset_found) {
 		dev_err(rcdev->dev, "Error reset register (0x%x)\n", offset);
 		return -EINVAL;
 	}

 	bit = reset_spec->args[1];
 	if (bit >= NPCM_RC_RESETS_PER_REG) {
 		dev_err(rcdev->dev, "Error reset number (%d)\n", bit);
 		return -EINVAL;
 	}

 	return (offset << 8) | bit;
 }

 static const struct of_device_id npcm_rc_match[] = {
 	{ .compatible = "nuvoton,npcm750-reset", .data = &npxm7xx_reset_info},
 	{ .compatible = "nuvoton,npcm845-reset", .data = &npxm8xx_reset_info},
 	{ }
 };

 static void npcm_usb_reset_npcm7xx(struct npcm_rc_data *rc)
 {
 	u32 mdlr, iprst1, iprst2, iprst3;
 	u32 ipsrst1_bits = 0;
 	u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST;
 	u32 ipsrst3_bits = 0;

 	/* checking which USB device is enabled */
 	regmap_read(rc->gcr_regmap, NPCM_MDLR_OFFSET, &mdlr);
 	if (!(mdlr & NPCM7XX_MDLR_USBD0))
 		ipsrst3_bits |= NPCM_IPSRST3_USBD0;
 	if (!(mdlr & NPCM7XX_MDLR_USBD1))
 		ipsrst1_bits |= NPCM_IPSRST1_USBD1;
 	if (!(mdlr & NPCM7XX_MDLR_USBD2_4))
 		ipsrst1_bits |= (NPCM_IPSRST1_USBD2 |
 				 NPCM_IPSRST1_USBD3 |
 				 NPCM_IPSRST1_USBD4);
 	if (!(mdlr & NPCM7XX_MDLR_USBD0)) {
 		ipsrst1_bits |= (NPCM_IPSRST1_USBD5 |
 				 NPCM_IPSRST1_USBD6);
 		ipsrst3_bits |= (NPCM_IPSRST3_USBD7 |
 				 NPCM_IPSRST3_USBD8 |
 				 NPCM_IPSRST3_USBD9);
 	}

 	/* assert reset USB PHY and USB devices */
 	iprst1 = readl(rc->base + NPCM_IPSRST1);
 	iprst2 = readl(rc->base + NPCM_IPSRST2);
 	iprst3 = readl(rc->base + NPCM_IPSRST3);

 	iprst1 |= ipsrst1_bits;
 	iprst2 |= ipsrst2_bits;
 	iprst3 |= (ipsrst3_bits | NPCM_IPSRST3_USBPHY1 |
 		   NPCM_IPSRST3_USBPHY2);

 	writel(iprst1, rc->base + NPCM_IPSRST1);
 	writel(iprst2, rc->base + NPCM_IPSRST2);
 	writel(iprst3, rc->base + NPCM_IPSRST3);

 	/* clear USB PHY RS bit */
 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
 			   NPCM_USBXPHYCTL_RS, 0);
 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
 			   NPCM_USBXPHYCTL_RS, 0);

 	/* deassert reset USB PHY */
 	iprst3 &= ~(NPCM_IPSRST3_USBPHY1 | NPCM_IPSRST3_USBPHY2);
 	writel(iprst3, rc->base + NPCM_IPSRST3);

 	udelay(50);

 	/* set USB PHY RS bit */
 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);

 	/* deassert reset USB devices*/
 	iprst1 &= ~ipsrst1_bits;
 	iprst2 &= ~ipsrst2_bits;
 	iprst3 &= ~ipsrst3_bits;

 	writel(iprst1, rc->base + NPCM_IPSRST1);
 	writel(iprst2, rc->base + NPCM_IPSRST2);
 	writel(iprst3, rc->base + NPCM_IPSRST3);
 }

 static void npcm_usb_reset_npcm8xx(struct npcm_rc_data *rc)
 {
 	u32 mdlr, iprst1, iprst2, iprst3, iprst4;
 	u32 ipsrst1_bits = 0;
 	u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST;
 	u32 ipsrst3_bits = 0;
 	u32 ipsrst4_bits = NPCM_IPSRST4_USB_HOST2 | NPCM_IPSRST4_USBPHY3;

 	/* checking which USB device is enabled */
 	regmap_read(rc->gcr_regmap, NPCM_MDLR_OFFSET, &mdlr);
 	if (!(mdlr & NPCM8XX_MDLR_USBD0_3)) {
 		ipsrst3_bits |= NPCM_IPSRST3_USBD0;
 		ipsrst1_bits |= (NPCM_IPSRST1_USBD1 |
 				 NPCM_IPSRST1_USBD2 |
 				 NPCM_IPSRST1_USBD3);
 	}
 	if (!(mdlr & NPCM8XX_MDLR_USBD4_7)) {
 		ipsrst1_bits |= (NPCM_IPSRST1_USBD4 |
 				 NPCM_IPSRST1_USBD5 |
 				 NPCM_IPSRST1_USBD6);
 		ipsrst3_bits |= NPCM_IPSRST3_USBD7;
 	}

 	if (!(mdlr & NPCM8XX_MDLR_USBD8))
 		ipsrst3_bits |= NPCM_IPSRST3_USBD8;
 	if (!(mdlr & NPCM8XX_MDLR_USBD9))
 		ipsrst3_bits |= NPCM_IPSRST3_USBD9;

 	/* assert reset USB PHY and USB devices */
 	iprst1 = readl(rc->base + NPCM_IPSRST1);
 	iprst2 = readl(rc->base + NPCM_IPSRST2);
 	iprst3 = readl(rc->base + NPCM_IPSRST3);
 	iprst4 = readl(rc->base + NPCM_IPSRST4);

 	iprst1 |= ipsrst1_bits;
 	iprst2 |= ipsrst2_bits;
 	iprst3 |= (ipsrst3_bits | NPCM_IPSRST3_USBPHY1 |
 		   NPCM_IPSRST3_USBPHY2);
 	iprst4 |= ipsrst4_bits;

 	writel(iprst1, rc->base + NPCM_IPSRST1);
 	writel(iprst2, rc->base + NPCM_IPSRST2);
 	writel(iprst3, rc->base + NPCM_IPSRST3);
 	writel(iprst4, rc->base + NPCM_IPSRST4);

 	/* clear USB PHY RS bit */
 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
 			   NPCM_USBXPHYCTL_RS, 0);
 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
 			   NPCM_USBXPHYCTL_RS, 0);
 	regmap_update_bits(rc->gcr_regmap, NPCM_USB3PHYCTL_OFFSET,
 			   NPCM_USBXPHYCTL_RS, 0);

 	/* deassert reset USB PHY */
 	iprst3 &= ~(NPCM_IPSRST3_USBPHY1 | NPCM_IPSRST3_USBPHY2);
 	writel(iprst3, rc->base + NPCM_IPSRST3);
 	iprst4 &= ~NPCM_IPSRST4_USBPHY3;
 	writel(iprst4, rc->base + NPCM_IPSRST4);

 	/* set USB PHY RS bit */
 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
 	regmap_update_bits(rc->gcr_regmap, NPCM_USB3PHYCTL_OFFSET,
 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);

 	/* deassert reset USB devices*/
 	iprst1 &= ~ipsrst1_bits;
 	iprst2 &= ~ipsrst2_bits;
 	iprst3 &= ~ipsrst3_bits;
 	iprst4 &= ~ipsrst4_bits;

 	writel(iprst1, rc->base + NPCM_IPSRST1);
 	writel(iprst2, rc->base + NPCM_IPSRST2);
 	writel(iprst3, rc->base + NPCM_IPSRST3);
 	writel(iprst4, rc->base + NPCM_IPSRST4);
 }

 /*
  *  The following procedure should be observed in USB PHY, USB device and
  *  USB host initialization at BMC boot
  */
 static int npcm_usb_reset(struct platform_device *pdev, struct npcm_rc_data *rc)
 {
 	struct device *dev = &pdev->dev;

 	rc->gcr_regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "nuvoton,sysgcr");
 	if (IS_ERR(rc->gcr_regmap)) {
 		dev_warn(&pdev->dev, "Failed to find nuvoton,sysgcr property, please update the device tree\n");
 		dev_info(&pdev->dev, "Using nuvoton,npcm750-gcr for Poleg backward compatibility\n");
 		rc->gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
 		if (IS_ERR(rc->gcr_regmap)) {
 			dev_err(&pdev->dev, "Failed to find nuvoton,npcm750-gcr");
 			return PTR_ERR(rc->gcr_regmap);
 		}
 	}

 	rc->info = device_get_match_data(dev);
 	switch (rc->info->bmc_id) {
 	case BMC_NPCM7XX:
 		npcm_usb_reset_npcm7xx(rc);
 		break;
 	case BMC_NPCM8XX:
 		npcm_usb_reset_npcm8xx(rc);
 		break;
 	default:
 		return -ENODEV;
 	}

 	return 0;
 }

 static const struct reset_control_ops npcm_rc_ops = {
 	.assert		= npcm_rc_assert,
 	.deassert	= npcm_rc_deassert,
 	.status		= npcm_rc_status,
 };

 static int npcm_rc_probe(struct platform_device *pdev)
 {
 	struct npcm_rc_data *rc;
 	int ret;

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

 	rc->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(rc->base))
 		return PTR_ERR(rc->base);

 	spin_lock_init(&rc->lock);

 	rc->rcdev.owner = THIS_MODULE;
 	rc->rcdev.ops = &npcm_rc_ops;
 	rc->rcdev.of_node = pdev->dev.of_node;
 	rc->rcdev.of_reset_n_cells = 2;
 	rc->rcdev.of_xlate = npcm_reset_xlate;

 	ret = devm_reset_controller_register(&pdev->dev, &rc->rcdev);
 	if (ret) {
 		dev_err(&pdev->dev, "unable to register device\n");
 		return ret;
 	}

 	if (npcm_usb_reset(pdev, rc))
 		dev_warn(&pdev->dev, "NPCM USB reset failed, can cause issues with UDC and USB host\n");

 	if (!of_property_read_u32(pdev->dev.of_node, "nuvoton,sw-reset-number",
 				  &rc->sw_reset_number)) {
 		if (rc->sw_reset_number && rc->sw_reset_number < 5) {
 			rc->restart_nb.priority = 192,
 			rc->restart_nb.notifier_call = npcm_rc_restart,
 			ret = register_restart_handler(&rc->restart_nb);
 			if (ret)
 				dev_warn(&pdev->dev, "failed to register restart handler\n");
 		}
 	}

 	return ret;
 }

 static struct platform_driver npcm_rc_driver = {
 	.probe	= npcm_rc_probe,
 	.driver	= {
 		.name			= "npcm-reset",
 		.of_match_table		= npcm_rc_match,
 		.suppress_bind_attrs	= true,
 	},
 };
 builtin_platform_driver(npcm_rc_driver);
	// SPDX-License-Identifier: GPL-2.0
	// Copyright (c) 2019 Nuvoton Technology corporation.

	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/init.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/property.h>
	#include <linux/reboot.h>
	#include <linux/reset-controller.h>
	#include <linux/spinlock.h>
	#include <linux/mfd/syscon.h>
	#include <linux/regmap.h>
	#include <linux/of_address.h>

	/* NPCM7xx GCR registers */
	#define NPCM_MDLR_OFFSET 0x7C
	#define NPCM7XX_MDLR_USBD0 BIT(9)
	#define NPCM7XX_MDLR_USBD1 BIT(8)
	#define NPCM7XX_MDLR_USBD2_4 BIT(21)
	#define NPCM7XX_MDLR_USBD5_9 BIT(22)

	/* NPCM8xx MDLR bits */
	#define NPCM8XX_MDLR_USBD0_3 BIT(9)
	#define NPCM8XX_MDLR_USBD4_7 BIT(22)
	#define NPCM8XX_MDLR_USBD8 BIT(24)
	#define NPCM8XX_MDLR_USBD9 BIT(21)

	#define NPCM_USB1PHYCTL_OFFSET 0x140
	#define NPCM_USB2PHYCTL_OFFSET 0x144
	#define NPCM_USB3PHYCTL_OFFSET 0x148
	#define NPCM_USBXPHYCTL_RS BIT(28)

	/* NPCM7xx Reset registers */
	#define NPCM_SWRSTR 0x14
	#define NPCM_SWRST BIT(2)

	#define NPCM_IPSRST1 0x20
	#define NPCM_IPSRST1_USBD1 BIT(5)
	#define NPCM_IPSRST1_USBD2 BIT(8)
	#define NPCM_IPSRST1_USBD3 BIT(25)
	#define NPCM_IPSRST1_USBD4 BIT(22)
	#define NPCM_IPSRST1_USBD5 BIT(23)
	#define NPCM_IPSRST1_USBD6 BIT(24)

	#define NPCM_IPSRST2 0x24
	#define NPCM_IPSRST2_USB_HOST BIT(26)

	#define NPCM_IPSRST3 0x34
	#define NPCM_IPSRST3_USBD0 BIT(4)
	#define NPCM_IPSRST3_USBD7 BIT(5)
	#define NPCM_IPSRST3_USBD8 BIT(6)
	#define NPCM_IPSRST3_USBD9 BIT(7)
	#define NPCM_IPSRST3_USBPHY1 BIT(24)
	#define NPCM_IPSRST3_USBPHY2 BIT(25)

	#define NPCM_IPSRST4 0x74
	#define NPCM_IPSRST4_USBPHY3 BIT(25)
	#define NPCM_IPSRST4_USB_HOST2 BIT(31)

	#define NPCM_RC_RESETS_PER_REG 32
	#define NPCM_MASK_RESETS GENMASK(4, 0)

	enum {
	BMC_NPCM7XX = 0,
	BMC_NPCM8XX,
	};

	static const u32 npxm7xx_ipsrst[] = {NPCM_IPSRST1, NPCM_IPSRST2, NPCM_IPSRST3};
	static const u32 npxm8xx_ipsrst[] = {NPCM_IPSRST1, NPCM_IPSRST2, NPCM_IPSRST3,
	NPCM_IPSRST4};

	struct npcm_reset_info {
	u32 bmc_id;
	u32 num_ipsrst;
	const u32 *ipsrst;
	};

	static const struct npcm_reset_info npxm7xx_reset_info[] = {
	{.bmc_id = BMC_NPCM7XX, .num_ipsrst = 3, .ipsrst = npxm7xx_ipsrst}};
	static const struct npcm_reset_info npxm8xx_reset_info[] = {
	{.bmc_id = BMC_NPCM8XX, .num_ipsrst = 4, .ipsrst = npxm8xx_ipsrst}};

	struct npcm_rc_data {
	struct reset_controller_dev rcdev;
	struct notifier_block restart_nb;
	const struct npcm_reset_info *info;
	struct regmap *gcr_regmap;
	u32 sw_reset_number;
	void __iomem *base;
	spinlock_t lock;
	};

	#define to_rc_data(p) container_of(p, struct npcm_rc_data, rcdev)

	static int npcm_rc_restart(struct notifier_block *nb, unsigned long mode,
	void *cmd)
	{
	struct npcm_rc_data *rc = container_of(nb, struct npcm_rc_data,
	restart_nb);

	writel(NPCM_SWRST << rc->sw_reset_number, rc->base + NPCM_SWRSTR);
	mdelay(1000);

	pr_emerg("%s: unable to restart system\n", __func__);

	return NOTIFY_DONE;
	}

	static int npcm_rc_setclear_reset(struct reset_controller_dev *rcdev,
	unsigned long id, bool set)
	{
	struct npcm_rc_data *rc = to_rc_data(rcdev);
	unsigned int rst_bit = BIT(id & NPCM_MASK_RESETS);
	unsigned int ctrl_offset = id >> 8;
	unsigned long flags;
	u32 stat;

	spin_lock_irqsave(&rc->lock, flags);
	stat = readl(rc->base + ctrl_offset);
	if (set)
	writel(stat \| rst_bit, rc->base + ctrl_offset);
	else
	writel(stat & ~rst_bit, rc->base + ctrl_offset);
	spin_unlock_irqrestore(&rc->lock, flags);

	return 0;
	}

	static int npcm_rc_assert(struct reset_controller_dev *rcdev, unsigned long id)
	{
	return npcm_rc_setclear_reset(rcdev, id, true);
	}

	static int npcm_rc_deassert(struct reset_controller_dev *rcdev,
	unsigned long id)
	{
	return npcm_rc_setclear_reset(rcdev, id, false);
	}

	static int npcm_rc_status(struct reset_controller_dev *rcdev,
	unsigned long id)
	{
	struct npcm_rc_data *rc = to_rc_data(rcdev);
	unsigned int rst_bit = BIT(id & NPCM_MASK_RESETS);
	unsigned int ctrl_offset = id >> 8;

	return (readl(rc->base + ctrl_offset) & rst_bit);
	}

	static int npcm_reset_xlate(struct reset_controller_dev *rcdev,
	const struct of_phandle_args *reset_spec)
	{
	struct npcm_rc_data *rc = to_rc_data(rcdev);
	unsigned int offset, bit;
	bool offset_found = false;
	int off_num;

	offset = reset_spec->args[0];
	for (off_num = 0 ; off_num < rc->info->num_ipsrst ; off_num++) {
	if (offset == rc->info->ipsrst[off_num]) {
	offset_found = true;
	break;
	}
	}

	if (!offset_found) {
	dev_err(rcdev->dev, "Error reset register (0x%x)\n", offset);
	return -EINVAL;
	}

	bit = reset_spec->args[1];
	if (bit >= NPCM_RC_RESETS_PER_REG) {
	dev_err(rcdev->dev, "Error reset number (%d)\n", bit);
	return -EINVAL;
	}

	return (offset << 8) \| bit;
	}

	static const struct of_device_id npcm_rc_match[] = {
	{ .compatible = "nuvoton,npcm750-reset", .data = &npxm7xx_reset_info},
	{ .compatible = "nuvoton,npcm845-reset", .data = &npxm8xx_reset_info},
	{ }
	};

	static void npcm_usb_reset_npcm7xx(struct npcm_rc_data *rc)
	{
	u32 mdlr, iprst1, iprst2, iprst3;
	u32 ipsrst1_bits = 0;
	u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST;
	u32 ipsrst3_bits = 0;

	/* checking which USB device is enabled */
	regmap_read(rc->gcr_regmap, NPCM_MDLR_OFFSET, &mdlr);
	if (!(mdlr & NPCM7XX_MDLR_USBD0))
	ipsrst3_bits \|= NPCM_IPSRST3_USBD0;
	if (!(mdlr & NPCM7XX_MDLR_USBD1))
	ipsrst1_bits \|= NPCM_IPSRST1_USBD1;
	if (!(mdlr & NPCM7XX_MDLR_USBD2_4))
	ipsrst1_bits \|= (NPCM_IPSRST1_USBD2 \|
	NPCM_IPSRST1_USBD3 \|
	NPCM_IPSRST1_USBD4);
	if (!(mdlr & NPCM7XX_MDLR_USBD0)) {
	ipsrst1_bits \|= (NPCM_IPSRST1_USBD5 \|
	NPCM_IPSRST1_USBD6);
	ipsrst3_bits \|= (NPCM_IPSRST3_USBD7 \|
	NPCM_IPSRST3_USBD8 \|
	NPCM_IPSRST3_USBD9);
	}

	/* assert reset USB PHY and USB devices */
	iprst1 = readl(rc->base + NPCM_IPSRST1);
	iprst2 = readl(rc->base + NPCM_IPSRST2);
	iprst3 = readl(rc->base + NPCM_IPSRST3);

	iprst1 \|= ipsrst1_bits;
	iprst2 \|= ipsrst2_bits;
	iprst3 \|= (ipsrst3_bits \| NPCM_IPSRST3_USBPHY1 \|
	NPCM_IPSRST3_USBPHY2);

	writel(iprst1, rc->base + NPCM_IPSRST1);
	writel(iprst2, rc->base + NPCM_IPSRST2);
	writel(iprst3, rc->base + NPCM_IPSRST3);

	/* clear USB PHY RS bit */
	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
	NPCM_USBXPHYCTL_RS, 0);
	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
	NPCM_USBXPHYCTL_RS, 0);

	/* deassert reset USB PHY */
	iprst3 &= ~(NPCM_IPSRST3_USBPHY1 \| NPCM_IPSRST3_USBPHY2);
	writel(iprst3, rc->base + NPCM_IPSRST3);

	udelay(50);

	/* set USB PHY RS bit */
	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
	NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
	NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);

	/* deassert reset USB devices*/
	iprst1 &= ~ipsrst1_bits;
	iprst2 &= ~ipsrst2_bits;
	iprst3 &= ~ipsrst3_bits;

	writel(iprst1, rc->base + NPCM_IPSRST1);
	writel(iprst2, rc->base + NPCM_IPSRST2);
	writel(iprst3, rc->base + NPCM_IPSRST3);
	}

	static void npcm_usb_reset_npcm8xx(struct npcm_rc_data *rc)
	{
	u32 mdlr, iprst1, iprst2, iprst3, iprst4;
	u32 ipsrst1_bits = 0;
	u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST;
	u32 ipsrst3_bits = 0;
	u32 ipsrst4_bits = NPCM_IPSRST4_USB_HOST2 \| NPCM_IPSRST4_USBPHY3;

	/* checking which USB device is enabled */
	regmap_read(rc->gcr_regmap, NPCM_MDLR_OFFSET, &mdlr);
	if (!(mdlr & NPCM8XX_MDLR_USBD0_3)) {
	ipsrst3_bits \|= NPCM_IPSRST3_USBD0;
	ipsrst1_bits \|= (NPCM_IPSRST1_USBD1 \|
	NPCM_IPSRST1_USBD2 \|
	NPCM_IPSRST1_USBD3);
	}
	if (!(mdlr & NPCM8XX_MDLR_USBD4_7)) {
	ipsrst1_bits \|= (NPCM_IPSRST1_USBD4 \|
	NPCM_IPSRST1_USBD5 \|
	NPCM_IPSRST1_USBD6);
	ipsrst3_bits \|= NPCM_IPSRST3_USBD7;
	}

	if (!(mdlr & NPCM8XX_MDLR_USBD8))
	ipsrst3_bits \|= NPCM_IPSRST3_USBD8;
	if (!(mdlr & NPCM8XX_MDLR_USBD9))
	ipsrst3_bits \|= NPCM_IPSRST3_USBD9;

	/* assert reset USB PHY and USB devices */
	iprst1 = readl(rc->base + NPCM_IPSRST1);
	iprst2 = readl(rc->base + NPCM_IPSRST2);
	iprst3 = readl(rc->base + NPCM_IPSRST3);
	iprst4 = readl(rc->base + NPCM_IPSRST4);

	iprst1 \|= ipsrst1_bits;
	iprst2 \|= ipsrst2_bits;
	iprst3 \|= (ipsrst3_bits \| NPCM_IPSRST3_USBPHY1 \|
	NPCM_IPSRST3_USBPHY2);
	iprst4 \|= ipsrst4_bits;

	writel(iprst1, rc->base + NPCM_IPSRST1);
	writel(iprst2, rc->base + NPCM_IPSRST2);
	writel(iprst3, rc->base + NPCM_IPSRST3);
	writel(iprst4, rc->base + NPCM_IPSRST4);

	/* clear USB PHY RS bit */
	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
	NPCM_USBXPHYCTL_RS, 0);
	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
	NPCM_USBXPHYCTL_RS, 0);
	regmap_update_bits(rc->gcr_regmap, NPCM_USB3PHYCTL_OFFSET,
	NPCM_USBXPHYCTL_RS, 0);

	/* deassert reset USB PHY */
	iprst3 &= ~(NPCM_IPSRST3_USBPHY1 \| NPCM_IPSRST3_USBPHY2);
	writel(iprst3, rc->base + NPCM_IPSRST3);
	iprst4 &= ~NPCM_IPSRST4_USBPHY3;
	writel(iprst4, rc->base + NPCM_IPSRST4);

	/* set USB PHY RS bit */
	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
	NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
	NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
	regmap_update_bits(rc->gcr_regmap, NPCM_USB3PHYCTL_OFFSET,
	NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);

	/* deassert reset USB devices*/
	iprst1 &= ~ipsrst1_bits;
	iprst2 &= ~ipsrst2_bits;
	iprst3 &= ~ipsrst3_bits;
	iprst4 &= ~ipsrst4_bits;

	writel(iprst1, rc->base + NPCM_IPSRST1);
	writel(iprst2, rc->base + NPCM_IPSRST2);
	writel(iprst3, rc->base + NPCM_IPSRST3);
	writel(iprst4, rc->base + NPCM_IPSRST4);
	}

	/*
	* The following procedure should be observed in USB PHY, USB device and
	* USB host initialization at BMC boot
	*/
	static int npcm_usb_reset(struct platform_device pdev, struct npcm_rc_data rc)
	{
	struct device *dev = &pdev->dev;

	rc->gcr_regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "nuvoton,sysgcr");
	if (IS_ERR(rc->gcr_regmap)) {
	dev_warn(&pdev->dev, "Failed to find nuvoton,sysgcr property, please update the device tree\n");
	dev_info(&pdev->dev, "Using nuvoton,npcm750-gcr for Poleg backward compatibility\n");
	rc->gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
	if (IS_ERR(rc->gcr_regmap)) {
	dev_err(&pdev->dev, "Failed to find nuvoton,npcm750-gcr");
	return PTR_ERR(rc->gcr_regmap);
	}
	}

	rc->info = device_get_match_data(dev);
	switch (rc->info->bmc_id) {
	case BMC_NPCM7XX:
	npcm_usb_reset_npcm7xx(rc);
	break;
	case BMC_NPCM8XX:
	npcm_usb_reset_npcm8xx(rc);
	break;
	default:
	return -ENODEV;
	}

	return 0;
	}

	static const struct reset_control_ops npcm_rc_ops = {
	.assert = npcm_rc_assert,
	.deassert = npcm_rc_deassert,
	.status = npcm_rc_status,
	};

	static int npcm_rc_probe(struct platform_device *pdev)
	{
	struct npcm_rc_data *rc;
	int ret;

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

	rc->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(rc->base))
	return PTR_ERR(rc->base);

	spin_lock_init(&rc->lock);

	rc->rcdev.owner = THIS_MODULE;
	rc->rcdev.ops = &npcm_rc_ops;
	rc->rcdev.of_node = pdev->dev.of_node;
	rc->rcdev.of_reset_n_cells = 2;
	rc->rcdev.of_xlate = npcm_reset_xlate;

	ret = devm_reset_controller_register(&pdev->dev, &rc->rcdev);
	if (ret) {
	dev_err(&pdev->dev, "unable to register device\n");
	return ret;
	}

	if (npcm_usb_reset(pdev, rc))
	dev_warn(&pdev->dev, "NPCM USB reset failed, can cause issues with UDC and USB host\n");

	if (!of_property_read_u32(pdev->dev.of_node, "nuvoton,sw-reset-number",
	&rc->sw_reset_number)) {
	if (rc->sw_reset_number && rc->sw_reset_number < 5) {
	rc->restart_nb.priority = 192,
	rc->restart_nb.notifier_call = npcm_rc_restart,
	ret = register_restart_handler(&rc->restart_nb);
	if (ret)
	dev_warn(&pdev->dev, "failed to register restart handler\n");
	}
	}

	return ret;
	}

	static struct platform_driver npcm_rc_driver = {
	.probe = npcm_rc_probe,
	.driver = {
	.name = "npcm-reset",
	.of_match_table = npcm_rc_match,
	.suppress_bind_attrs = true,
	},
	};
	builtin_platform_driver(npcm_rc_driver);