xref: /openbmc/u-boot/drivers/usb/host/xhci-omap.c (revision afea2c96)
1 /*
2  * OMAP USB HOST xHCI Controller
3  *
4  * (C) Copyright 2013
5  * Texas Instruments, <www.ti.com>
6  *
7  * Author: Dan Murphy <dmurphy@ti.com>
8  *
9  * SPDX-License-Identifier:	GPL-2.0+
10  */
11 
12 #include <common.h>
13 #include <usb.h>
14 #include <asm-generic/errno.h>
15 #include <asm/omap_common.h>
16 #include <asm/arch/cpu.h>
17 #include <asm/arch/sys_proto.h>
18 
19 #include <linux/compat.h>
20 #include <linux/usb/dwc3.h>
21 #include <linux/usb/xhci-omap.h>
22 
23 #include "xhci.h"
24 
25 /* Declare global data pointer */
26 DECLARE_GLOBAL_DATA_PTR;
27 
28 static struct omap_xhci omap;
29 
30 inline int __board_usb_init(int index, enum usb_init_type init)
31 {
32 	return 0;
33 }
34 int board_usb_init(int index, enum usb_init_type init)
35 	__attribute__((weak, alias("__board_usb_init")));
36 
37 static void dwc3_set_mode(struct dwc3 *dwc3_reg, u32 mode)
38 {
39 	clrsetbits_le32(&dwc3_reg->g_ctl,
40 			DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG),
41 			DWC3_GCTL_PRTCAPDIR(mode));
42 }
43 
44 static void dwc3_core_soft_reset(struct dwc3 *dwc3_reg)
45 {
46 	/* Before Resetting PHY, put Core in Reset */
47 	setbits_le32(&dwc3_reg->g_ctl, DWC3_GCTL_CORESOFTRESET);
48 
49 	omap_reset_usb_phy(dwc3_reg);
50 
51 	/* After PHYs are stable we can take Core out of reset state */
52 	clrbits_le32(&dwc3_reg->g_ctl, DWC3_GCTL_CORESOFTRESET);
53 }
54 
55 static int dwc3_core_init(struct dwc3 *dwc3_reg)
56 {
57 	u32 reg;
58 	u32 revision;
59 	unsigned int dwc3_hwparams1;
60 
61 	revision = readl(&dwc3_reg->g_snpsid);
62 	/* This should read as U3 followed by revision number */
63 	if ((revision & DWC3_GSNPSID_MASK) != 0x55330000) {
64 		puts("this is not a DesignWare USB3 DRD Core\n");
65 		return -1;
66 	}
67 
68 	dwc3_core_soft_reset(dwc3_reg);
69 
70 	dwc3_hwparams1 = readl(&dwc3_reg->g_hwparams1);
71 
72 	reg = readl(&dwc3_reg->g_ctl);
73 	reg &= ~DWC3_GCTL_SCALEDOWN_MASK;
74 	reg &= ~DWC3_GCTL_DISSCRAMBLE;
75 	switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc3_hwparams1)) {
76 	case DWC3_GHWPARAMS1_EN_PWROPT_CLK:
77 		reg &= ~DWC3_GCTL_DSBLCLKGTNG;
78 		break;
79 	default:
80 		debug("No power optimization available\n");
81 	}
82 
83 	/*
84 	 * WORKAROUND: DWC3 revisions <1.90a have a bug
85 	 * where the device can fail to connect at SuperSpeed
86 	 * and falls back to high-speed mode which causes
87 	 * the device to enter a Connect/Disconnect loop
88 	 */
89 	if ((revision & DWC3_REVISION_MASK) < 0x190a)
90 		reg |= DWC3_GCTL_U2RSTECN;
91 
92 	writel(reg, &dwc3_reg->g_ctl);
93 
94 	return 0;
95 }
96 
97 static int omap_xhci_core_init(struct omap_xhci *omap)
98 {
99 	int ret = 0;
100 
101 	omap_enable_phy(omap);
102 
103 	ret = dwc3_core_init(omap->dwc3_reg);
104 	if (ret) {
105 		debug("%s:failed to initialize core\n", __func__);
106 		return ret;
107 	}
108 
109 	/* We are hard-coding DWC3 core to Host Mode */
110 	dwc3_set_mode(omap->dwc3_reg, DWC3_GCTL_PRTCAP_HOST);
111 
112 	return ret;
113 }
114 
115 static void omap_xhci_core_exit(struct omap_xhci *omap)
116 {
117 	usb_phy_power(0);
118 }
119 
120 int xhci_hcd_init(int index, struct xhci_hccr **hccr, struct xhci_hcor **hcor)
121 {
122 	struct omap_xhci *ctx = &omap;
123 	int ret = 0;
124 
125 	ctx->hcd = (struct xhci_hccr *)OMAP_XHCI_BASE;
126 	ctx->dwc3_reg = (struct dwc3 *)((char *)(ctx->hcd) + DWC3_REG_OFFSET);
127 	ctx->usb3_phy = (struct omap_usb3_phy *)OMAP_OCP1_SCP_BASE;
128 	ctx->otg_wrapper = (struct omap_dwc_wrapper *)OMAP_OTG_WRAPPER_BASE;
129 
130 	ret = board_usb_init(index, USB_INIT_HOST);
131 	if (ret != 0) {
132 		puts("Failed to initialize board for USB\n");
133 		return ret;
134 	}
135 
136 	ret = omap_xhci_core_init(ctx);
137 	if (ret < 0) {
138 		puts("Failed to initialize xhci\n");
139 		return ret;
140 	}
141 
142 	*hccr = (struct xhci_hccr *)(OMAP_XHCI_BASE);
143 	*hcor = (struct xhci_hcor *)((uint32_t) *hccr
144 				+ HC_LENGTH(xhci_readl(&(*hccr)->cr_capbase)));
145 
146 	debug("omap-xhci: init hccr %x and hcor %x hc_length %d\n",
147 	      (uint32_t)*hccr, (uint32_t)*hcor,
148 	      (uint32_t)HC_LENGTH(xhci_readl(&(*hccr)->cr_capbase)));
149 
150 	return ret;
151 }
152 
153 void xhci_hcd_stop(int index)
154 {
155 	struct omap_xhci *ctx = &omap;
156 
157 	omap_xhci_core_exit(ctx);
158 }
159