usb.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * USB block power/access management abstraction.
 *
 * Au1000+: The OHCI block control register is at the far end of the OHCI memory
 *	    area. Au1550 has OHCI on different base address. No need to handle
 *	    UDC here.
 * Au1200:  one register to control access and clocks to O/EHCI, UDC and OTG
 *	    as well as the PHY for EHCI and UDC.
 *
 */

#include <linux/clk.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/syscore_ops.h>
#include <asm/cpu.h>
#include <asm/mach-au1x00/au1000.h>

/* control register offsets */
#define AU1000_OHCICFG	0x7fffc
#define AU1550_OHCICFG	0x07ffc
#define AU1200_USBCFG	0x04

/* Au1000 USB block config bits */
#define USBHEN_RD	(1 << 4)		/* OHCI reset-done indicator */
#define USBHEN_CE	(1 << 3)		/* OHCI block clock enable */
#define USBHEN_E	(1 << 2)		/* OHCI block enable */
#define USBHEN_C	(1 << 1)		/* OHCI block coherency bit */
#define USBHEN_BE	(1 << 0)		/* OHCI Big-Endian */

/* Au1200 USB config bits */
#define USBCFG_PFEN	(1 << 31)		/* prefetch enable (undoc) */
#define USBCFG_RDCOMB	(1 << 30)		/* read combining (undoc) */
#define USBCFG_UNKNOWN	(5 << 20)		/* unknown, leave this way */
#define USBCFG_SSD	(1 << 23)		/* serial short detect en */
#define USBCFG_PPE	(1 << 19)		/* HS PHY PLL */
#define USBCFG_UCE	(1 << 18)		/* UDC clock enable */
#define USBCFG_ECE	(1 << 17)		/* EHCI clock enable */
#define USBCFG_OCE	(1 << 16)		/* OHCI clock enable */
#define USBCFG_FLA(x)	(((x) & 0x3f) << 8)
#define USBCFG_UCAM	(1 << 7)		/* coherent access (undoc) */
#define USBCFG_GME	(1 << 6)		/* OTG mem access */
#define USBCFG_DBE	(1 << 5)		/* UDC busmaster enable */
#define USBCFG_DME	(1 << 4)		/* UDC mem enable */
#define USBCFG_EBE	(1 << 3)		/* EHCI busmaster enable */
#define USBCFG_EME	(1 << 2)		/* EHCI mem enable */
#define USBCFG_OBE	(1 << 1)		/* OHCI busmaster enable */
#define USBCFG_OME	(1 << 0)		/* OHCI mem enable */
#define USBCFG_INIT_AU1200	(USBCFG_PFEN | USBCFG_RDCOMB | USBCFG_UNKNOWN |\
				 USBCFG_SSD | USBCFG_FLA(0x20) | USBCFG_UCAM | \
				 USBCFG_GME | USBCFG_DBE | USBCFG_DME |	       \
				 USBCFG_EBE | USBCFG_EME | USBCFG_OBE |	       \
				 USBCFG_OME)

/* Au1300 USB config registers */
#define USB_DWC_CTRL1		0x00
#define USB_DWC_CTRL2		0x04
#define USB_VBUS_TIMER		0x10
#define USB_SBUS_CTRL		0x14
#define USB_MSR_ERR		0x18
#define USB_DWC_CTRL3		0x1C
#define USB_DWC_CTRL4		0x20
#define USB_OTG_STATUS		0x28
#define USB_DWC_CTRL5		0x2C
#define USB_DWC_CTRL6		0x30
#define USB_DWC_CTRL7		0x34
#define USB_PHY_STATUS		0xC0
#define USB_INT_STATUS		0xC4
#define USB_INT_ENABLE		0xC8

#define USB_DWC_CTRL1_OTGD	0x04 /* set to DISable OTG */
#define USB_DWC_CTRL1_HSTRS	0x02 /* set to ENable EHCI */
#define USB_DWC_CTRL1_DCRS	0x01 /* set to ENable UDC */

#define USB_DWC_CTRL2_PHY1RS	0x04 /* set to enable PHY1 */
#define USB_DWC_CTRL2_PHY0RS	0x02 /* set to enable PHY0 */
#define USB_DWC_CTRL2_PHYRS	0x01 /* set to enable PHY */

#define USB_DWC_CTRL3_OHCI1_CKEN	(1 << 19)
#define USB_DWC_CTRL3_OHCI0_CKEN	(1 << 18)
#define USB_DWC_CTRL3_EHCI0_CKEN	(1 << 17)
#define USB_DWC_CTRL3_OTG0_CKEN		(1 << 16)

#define USB_SBUS_CTRL_SBCA		0x04 /* coherent access */

#define USB_INTEN_FORCE			0x20
#define USB_INTEN_PHY			0x10
#define USB_INTEN_UDC			0x08
#define USB_INTEN_EHCI			0x04
#define USB_INTEN_OHCI1			0x02
#define USB_INTEN_OHCI0			0x01

static DEFINE_SPINLOCK(alchemy_usb_lock);

static inline void __au1300_usb_phyctl(void __iomem *base, int enable)
{
	unsigned long r, s;

	r = __raw_readl(base + USB_DWC_CTRL2);
	s = __raw_readl(base + USB_DWC_CTRL3);

	s &= USB_DWC_CTRL3_OHCI1_CKEN | USB_DWC_CTRL3_OHCI0_CKEN |
		USB_DWC_CTRL3_EHCI0_CKEN | USB_DWC_CTRL3_OTG0_CKEN;

	if (enable) {
		/* simply enable all PHYs */
		r |= USB_DWC_CTRL2_PHY1RS | USB_DWC_CTRL2_PHY0RS |
		     USB_DWC_CTRL2_PHYRS;
		__raw_writel(r, base + USB_DWC_CTRL2);
		wmb();
	} else if (!s) {
		/* no USB block active, do disable all PHYs */
		r &= ~(USB_DWC_CTRL2_PHY1RS | USB_DWC_CTRL2_PHY0RS |
		       USB_DWC_CTRL2_PHYRS);
		__raw_writel(r, base + USB_DWC_CTRL2);
		wmb();
	}
}

static inline void __au1300_ohci_control(void __iomem *base, int enable, int id)
{
	unsigned long r;

	if (enable) {
		__raw_writel(1, base + USB_DWC_CTRL7);	/* start OHCI clock */
		wmb();

		r = __raw_readl(base + USB_DWC_CTRL3);	/* enable OHCI block */
		r |= (id == 0) ? USB_DWC_CTRL3_OHCI0_CKEN
			       : USB_DWC_CTRL3_OHCI1_CKEN;
		__raw_writel(r, base + USB_DWC_CTRL3);
		wmb();

		__au1300_usb_phyctl(base, enable);	/* power up the PHYs */

		r = __raw_readl(base + USB_INT_ENABLE);
		r |= (id == 0) ? USB_INTEN_OHCI0 : USB_INTEN_OHCI1;
		__raw_writel(r, base + USB_INT_ENABLE);
		wmb();

		/* reset the OHCI start clock bit */
		__raw_writel(0, base + USB_DWC_CTRL7);
		wmb();
	} else {
		r = __raw_readl(base + USB_INT_ENABLE);
		r &= ~((id == 0) ? USB_INTEN_OHCI0 : USB_INTEN_OHCI1);
		__raw_writel(r, base + USB_INT_ENABLE);
		wmb();

		r = __raw_readl(base + USB_DWC_CTRL3);
		r &= ~((id == 0) ? USB_DWC_CTRL3_OHCI0_CKEN
				 : USB_DWC_CTRL3_OHCI1_CKEN);
		__raw_writel(r, base + USB_DWC_CTRL3);
		wmb();

		__au1300_usb_phyctl(base, enable);
	}
}

static inline void __au1300_ehci_control(void __iomem *base, int enable)
{
	unsigned long r;

	if (enable) {
		r = __raw_readl(base + USB_DWC_CTRL3);
		r |= USB_DWC_CTRL3_EHCI0_CKEN;
		__raw_writel(r, base + USB_DWC_CTRL3);
		wmb();

		r = __raw_readl(base + USB_DWC_CTRL1);
		r |= USB_DWC_CTRL1_HSTRS;
		__raw_writel(r, base + USB_DWC_CTRL1);
		wmb();

		__au1300_usb_phyctl(base, enable);

		r = __raw_readl(base + USB_INT_ENABLE);
		r |= USB_INTEN_EHCI;
		__raw_writel(r, base + USB_INT_ENABLE);
		wmb();
	} else {
		r = __raw_readl(base + USB_INT_ENABLE);
		r &= ~USB_INTEN_EHCI;
		__raw_writel(r, base + USB_INT_ENABLE);
		wmb();

		r = __raw_readl(base + USB_DWC_CTRL1);
		r &= ~USB_DWC_CTRL1_HSTRS;
		__raw_writel(r, base + USB_DWC_CTRL1);
		wmb();

		r = __raw_readl(base + USB_DWC_CTRL3);
		r &= ~USB_DWC_CTRL3_EHCI0_CKEN;
		__raw_writel(r, base + USB_DWC_CTRL3);
		wmb();

		__au1300_usb_phyctl(base, enable);
	}
}

static inline void __au1300_udc_control(void __iomem *base, int enable)
{
	unsigned long r;

	if (enable) {
		r = __raw_readl(base + USB_DWC_CTRL1);
		r |= USB_DWC_CTRL1_DCRS;
		__raw_writel(r, base + USB_DWC_CTRL1);
		wmb();

		__au1300_usb_phyctl(base, enable);

		r = __raw_readl(base + USB_INT_ENABLE);
		r |= USB_INTEN_UDC;
		__raw_writel(r, base + USB_INT_ENABLE);
		wmb();
	} else {
		r = __raw_readl(base + USB_INT_ENABLE);
		r &= ~USB_INTEN_UDC;
		__raw_writel(r, base + USB_INT_ENABLE);
		wmb();

		r = __raw_readl(base + USB_DWC_CTRL1);
		r &= ~USB_DWC_CTRL1_DCRS;
		__raw_writel(r, base + USB_DWC_CTRL1);
		wmb();

		__au1300_usb_phyctl(base, enable);
	}
}

static inline void __au1300_otg_control(void __iomem *base, int enable)
{
	unsigned long r;
	if (enable) {
		r = __raw_readl(base + USB_DWC_CTRL3);
		r |= USB_DWC_CTRL3_OTG0_CKEN;
		__raw_writel(r, base + USB_DWC_CTRL3);
		wmb();

		r = __raw_readl(base + USB_DWC_CTRL1);
		r &= ~USB_DWC_CTRL1_OTGD;
		__raw_writel(r, base + USB_DWC_CTRL1);
		wmb();

		__au1300_usb_phyctl(base, enable);
	} else {
		r = __raw_readl(base + USB_DWC_CTRL1);
		r |= USB_DWC_CTRL1_OTGD;
		__raw_writel(r, base + USB_DWC_CTRL1);
		wmb();

		r = __raw_readl(base + USB_DWC_CTRL3);
		r &= ~USB_DWC_CTRL3_OTG0_CKEN;
		__raw_writel(r, base + USB_DWC_CTRL3);
		wmb();

		__au1300_usb_phyctl(base, enable);
	}
}

static inline int au1300_usb_control(int block, int enable)
{
	void __iomem *base =
		(void __iomem *)KSEG1ADDR(AU1300_USB_CTL_PHYS_ADDR);
	int ret = 0;

	switch (block) {
	case ALCHEMY_USB_OHCI0:
		__au1300_ohci_control(base, enable, 0);
		break;
	case ALCHEMY_USB_OHCI1:
		__au1300_ohci_control(base, enable, 1);
		break;
	case ALCHEMY_USB_EHCI0:
		__au1300_ehci_control(base, enable);
		break;
	case ALCHEMY_USB_UDC0:
		__au1300_udc_control(base, enable);
		break;
	case ALCHEMY_USB_OTG0:
		__au1300_otg_control(base, enable);
		break;
	default:
		ret = -ENODEV;
	}
	return ret;
}

static inline void au1300_usb_init(void)
{
	void __iomem *base =
		(void __iomem *)KSEG1ADDR(AU1300_USB_CTL_PHYS_ADDR);

	/* set some sane defaults.  Note: we don't fiddle with DWC_CTRL4
	 * here at all: Port 2 routing (EHCI or UDC) must be set either
	 * by boot firmware or platform init code; I can't autodetect
	 * a sane setting.
	 */
	__raw_writel(0, base + USB_INT_ENABLE); /* disable all USB irqs */
	wmb();
	__raw_writel(0, base + USB_DWC_CTRL3); /* disable all clocks */
	wmb();
	__raw_writel(~0, base + USB_MSR_ERR); /* clear all errors */
	wmb();
	__raw_writel(~0, base + USB_INT_STATUS); /* clear int status */
	wmb();
	/* set coherent access bit */
	__raw_writel(USB_SBUS_CTRL_SBCA, base + USB_SBUS_CTRL);
	wmb();
}

static inline void __au1200_ohci_control(void __iomem *base, int enable)
{
	unsigned long r = __raw_readl(base + AU1200_USBCFG);
	if (enable) {
		__raw_writel(r | USBCFG_OCE, base + AU1200_USBCFG);
		wmb();
		udelay(2000);
	} else {
		__raw_writel(r & ~USBCFG_OCE, base + AU1200_USBCFG);
		wmb();
		udelay(1000);
	}
}

static inline void __au1200_ehci_control(void __iomem *base, int enable)
{
	unsigned long r = __raw_readl(base + AU1200_USBCFG);
	if (enable) {
		__raw_writel(r | USBCFG_ECE | USBCFG_PPE, base + AU1200_USBCFG);
		wmb();
		udelay(1000);
	} else {
		if (!(r & USBCFG_UCE))		/* UDC also off? */
			r &= ~USBCFG_PPE;	/* yes: disable HS PHY PLL */
		__raw_writel(r & ~USBCFG_ECE, base + AU1200_USBCFG);
		wmb();
		udelay(1000);
	}
}

static inline void __au1200_udc_control(void __iomem *base, int enable)
{
	unsigned long r = __raw_readl(base + AU1200_USBCFG);
	if (enable) {
		__raw_writel(r | USBCFG_UCE | USBCFG_PPE, base + AU1200_USBCFG);
		wmb();
	} else {
		if (!(r & USBCFG_ECE))		/* EHCI also off? */
			r &= ~USBCFG_PPE;	/* yes: disable HS PHY PLL */
		__raw_writel(r & ~USBCFG_UCE, base + AU1200_USBCFG);
		wmb();
	}
}

static inline int au1200_usb_control(int block, int enable)
{
	void __iomem *base =
			(void __iomem *)KSEG1ADDR(AU1200_USB_CTL_PHYS_ADDR);

	switch (block) {
	case ALCHEMY_USB_OHCI0:
		__au1200_ohci_control(base, enable);
		break;
	case ALCHEMY_USB_UDC0:
		__au1200_udc_control(base, enable);
		break;
	case ALCHEMY_USB_EHCI0:
		__au1200_ehci_control(base, enable);
		break;
	default:
		return -ENODEV;
	}
	return 0;
}


/* initialize USB block(s) to a known working state */
static inline void au1200_usb_init(void)
{
	void __iomem *base =
			(void __iomem *)KSEG1ADDR(AU1200_USB_CTL_PHYS_ADDR);
	__raw_writel(USBCFG_INIT_AU1200, base + AU1200_USBCFG);
	wmb();
	udelay(1000);
}

static inline int au1000_usb_init(unsigned long rb, int reg)
{
	void __iomem *base = (void __iomem *)KSEG1ADDR(rb + reg);
	unsigned long r = __raw_readl(base);
	struct clk *c;

	/* 48MHz check. Don't init if no one can provide it */
	c = clk_get(NULL, "usbh_clk");
	if (IS_ERR(c))
		return -ENODEV;
	if (clk_round_rate(c, 48000000) != 48000000) {
		clk_put(c);
		return -ENODEV;
	}
	if (clk_set_rate(c, 48000000)) {
		clk_put(c);
		return -ENODEV;
	}
	clk_put(c);

#if defined(__BIG_ENDIAN)
	r |= USBHEN_BE;
#endif
	r |= USBHEN_C;

	__raw_writel(r, base);
	wmb();
	udelay(1000);

	return 0;
}


static inline void __au1xx0_ohci_control(int enable, unsigned long rb, int creg)
{
	void __iomem *base = (void __iomem *)KSEG1ADDR(rb);
	unsigned long r = __raw_readl(base + creg);
	struct clk *c = clk_get(NULL, "usbh_clk");

	if (IS_ERR(c))
		return;

	if (enable) {
		if (clk_prepare_enable(c))
			goto out;

		__raw_writel(r | USBHEN_CE, base + creg);
		wmb();
		udelay(1000);
		__raw_writel(r | USBHEN_CE | USBHEN_E, base + creg);
		wmb();
		udelay(1000);

		/* wait for reset complete (read reg twice: au1500 erratum) */
		while (__raw_readl(base + creg),
			!(__raw_readl(base + creg) & USBHEN_RD))
			udelay(1000);
	} else {
		__raw_writel(r & ~(USBHEN_CE | USBHEN_E), base + creg);
		wmb();
		clk_disable_unprepare(c);
	}
out:
	clk_put(c);
}

static inline int au1000_usb_control(int block, int enable, unsigned long rb,
				     int creg)
{
	int ret = 0;

	switch (block) {
	case ALCHEMY_USB_OHCI0:
		__au1xx0_ohci_control(enable, rb, creg);
		break;
	default:
		ret = -ENODEV;
	}
	return ret;
}

/*
 * alchemy_usb_control - control Alchemy on-chip USB blocks
 * @block:	USB block to target
 * @enable:	set 1 to enable a block, 0 to disable
 */
int alchemy_usb_control(int block, int enable)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&alchemy_usb_lock, flags);
	switch (alchemy_get_cputype()) {
	case ALCHEMY_CPU_AU1000:
	case ALCHEMY_CPU_AU1500:
	case ALCHEMY_CPU_AU1100:
		ret = au1000_usb_control(block, enable,
			AU1000_USB_OHCI_PHYS_ADDR, AU1000_OHCICFG);
		break;
	case ALCHEMY_CPU_AU1550:
		ret = au1000_usb_control(block, enable,
			AU1550_USB_OHCI_PHYS_ADDR, AU1550_OHCICFG);
		break;
	case ALCHEMY_CPU_AU1200:
		ret = au1200_usb_control(block, enable);
		break;
	case ALCHEMY_CPU_AU1300:
		ret = au1300_usb_control(block, enable);
		break;
	default:
		ret = -ENODEV;
	}
	spin_unlock_irqrestore(&alchemy_usb_lock, flags);
	return ret;
}
EXPORT_SYMBOL_GPL(alchemy_usb_control);


static unsigned long alchemy_usb_pmdata[2];

static void au1000_usb_pm(unsigned long br, int creg, int susp)
{
	void __iomem *base = (void __iomem *)KSEG1ADDR(br);

	if (susp) {
		alchemy_usb_pmdata[0] = __raw_readl(base + creg);
		/* There appears to be some undocumented reset register.... */
		__raw_writel(0, base + 0x04);
		wmb();
		__raw_writel(0, base + creg);
		wmb();
	} else {
		__raw_writel(alchemy_usb_pmdata[0], base + creg);
		wmb();
	}
}

static void au1200_usb_pm(int susp)
{
	void __iomem *base =
			(void __iomem *)KSEG1ADDR(AU1200_USB_OTG_PHYS_ADDR);
	if (susp) {
		/* save OTG_CAP/MUX registers which indicate port routing */
		/* FIXME: write an OTG driver to do that */
		alchemy_usb_pmdata[0] = __raw_readl(base + 0x00);
		alchemy_usb_pmdata[1] = __raw_readl(base + 0x04);
	} else {
		/* restore access to all MMIO areas */
		au1200_usb_init();

		/* restore OTG_CAP/MUX registers */
		__raw_writel(alchemy_usb_pmdata[0], base + 0x00);
		__raw_writel(alchemy_usb_pmdata[1], base + 0x04);
		wmb();
	}
}

static void au1300_usb_pm(int susp)
{
	void __iomem *base =
			(void __iomem *)KSEG1ADDR(AU1300_USB_CTL_PHYS_ADDR);
	/* remember Port2 routing */
	if (susp) {
		alchemy_usb_pmdata[0] = __raw_readl(base + USB_DWC_CTRL4);
	} else {
		au1300_usb_init();
		__raw_writel(alchemy_usb_pmdata[0], base + USB_DWC_CTRL4);
		wmb();
	}
}

static void alchemy_usb_pm(int susp)
{
	switch (alchemy_get_cputype()) {
	case ALCHEMY_CPU_AU1000:
	case ALCHEMY_CPU_AU1500:
	case ALCHEMY_CPU_AU1100:
		au1000_usb_pm(AU1000_USB_OHCI_PHYS_ADDR, AU1000_OHCICFG, susp);
		break;
	case ALCHEMY_CPU_AU1550:
		au1000_usb_pm(AU1550_USB_OHCI_PHYS_ADDR, AU1550_OHCICFG, susp);
		break;
	case ALCHEMY_CPU_AU1200:
		au1200_usb_pm(susp);
		break;
	case ALCHEMY_CPU_AU1300:
		au1300_usb_pm(susp);
		break;
	}
}

static int alchemy_usb_suspend(void)
{
	alchemy_usb_pm(1);
	return 0;
}

static void alchemy_usb_resume(void)
{
	alchemy_usb_pm(0);
}

static struct syscore_ops alchemy_usb_pm_ops = {
	.suspend	= alchemy_usb_suspend,
	.resume		= alchemy_usb_resume,
};

static int __init alchemy_usb_init(void)
{
	int ret = 0;

	switch (alchemy_get_cputype()) {
	case ALCHEMY_CPU_AU1000:
	case ALCHEMY_CPU_AU1500:
	case ALCHEMY_CPU_AU1100:
		ret = au1000_usb_init(AU1000_USB_OHCI_PHYS_ADDR,
				      AU1000_OHCICFG);
		break;
	case ALCHEMY_CPU_AU1550:
		ret = au1000_usb_init(AU1550_USB_OHCI_PHYS_ADDR,
				      AU1550_OHCICFG);
		break;
	case ALCHEMY_CPU_AU1200:
		au1200_usb_init();
		break;
	case ALCHEMY_CPU_AU1300:
		au1300_usb_init();
		break;
	}

	if (!ret)
		register_syscore_ops(&alchemy_usb_pm_ops);

	return ret;
}
arch_initcall(alchemy_usb_init);