xref: /openbmc/u-boot/drivers/usb/host/xhci-dwc3.c (revision 6b44ae6b)
1 /*
2  * Copyright 2015 Freescale Semiconductor, Inc.
3  *
4  * DWC3 controller driver
5  *
6  * Author: Ramneek Mehresh<ramneek.mehresh@freescale.com>
7  *
8  * SPDX-License-Identifier:     GPL-2.0+
9  */
10 
11 #include <common.h>
12 #include <asm/io.h>
13 #include <linux/usb/dwc3.h>
14 
15 void dwc3_set_mode(struct dwc3 *dwc3_reg, u32 mode)
16 {
17 	clrsetbits_le32(&dwc3_reg->g_ctl,
18 			DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG),
19 			DWC3_GCTL_PRTCAPDIR(mode));
20 }
21 
22 void dwc3_phy_reset(struct dwc3 *dwc3_reg)
23 {
24 	/* Assert USB3 PHY reset */
25 	setbits_le32(&dwc3_reg->g_usb3pipectl[0], DWC3_GUSB3PIPECTL_PHYSOFTRST);
26 
27 	/* Assert USB2 PHY reset */
28 	setbits_le32(&dwc3_reg->g_usb2phycfg, DWC3_GUSB2PHYCFG_PHYSOFTRST);
29 
30 	mdelay(100);
31 
32 	/* Clear USB3 PHY reset */
33 	clrbits_le32(&dwc3_reg->g_usb3pipectl[0], DWC3_GUSB3PIPECTL_PHYSOFTRST);
34 
35 	/* Clear USB2 PHY reset */
36 	clrbits_le32(&dwc3_reg->g_usb2phycfg, DWC3_GUSB2PHYCFG_PHYSOFTRST);
37 }
38 
39 void dwc3_core_soft_reset(struct dwc3 *dwc3_reg)
40 {
41 	/* Before Resetting PHY, put Core in Reset */
42 	setbits_le32(&dwc3_reg->g_ctl, DWC3_GCTL_CORESOFTRESET);
43 
44 	/* reset USB3 phy - if required */
45 	dwc3_phy_reset(dwc3_reg);
46 
47 	/* After PHYs are stable we can take Core out of reset state */
48 	clrbits_le32(&dwc3_reg->g_ctl, DWC3_GCTL_CORESOFTRESET);
49 }
50 
51 int dwc3_core_init(struct dwc3 *dwc3_reg)
52 {
53 	u32 reg;
54 	u32 revision;
55 	unsigned int dwc3_hwparams1;
56 
57 	revision = readl(&dwc3_reg->g_snpsid);
58 	/* This should read as U3 followed by revision number */
59 	if ((revision & DWC3_GSNPSID_MASK) != 0x55330000) {
60 		puts("this is not a DesignWare USB3 DRD Core\n");
61 		return -1;
62 	}
63 
64 	dwc3_core_soft_reset(dwc3_reg);
65 
66 	dwc3_hwparams1 = readl(&dwc3_reg->g_hwparams1);
67 
68 	reg = readl(&dwc3_reg->g_ctl);
69 	reg &= ~DWC3_GCTL_SCALEDOWN_MASK;
70 	reg &= ~DWC3_GCTL_DISSCRAMBLE;
71 	switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc3_hwparams1)) {
72 	case DWC3_GHWPARAMS1_EN_PWROPT_CLK:
73 		reg &= ~DWC3_GCTL_DSBLCLKGTNG;
74 		break;
75 	default:
76 		debug("No power optimization available\n");
77 	}
78 
79 	/*
80 	 * WORKAROUND: DWC3 revisions <1.90a have a bug
81 	 * where the device can fail to connect at SuperSpeed
82 	 * and falls back to high-speed mode which causes
83 	 * the device to enter a Connect/Disconnect loop
84 	 */
85 	if ((revision & DWC3_REVISION_MASK) < 0x190a)
86 		reg |= DWC3_GCTL_U2RSTECN;
87 
88 	writel(reg, &dwc3_reg->g_ctl);
89 
90 	return 0;
91 }
92 
93 void dwc3_set_fladj(struct dwc3 *dwc3_reg, u32 val)
94 {
95 	setbits_le32(&dwc3_reg->g_fladj, GFLADJ_30MHZ_REG_SEL |
96 			GFLADJ_30MHZ(val));
97 }
98