1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * EHCI HCD (Host Controller Driver) for USB.
4  *
5  * Bus Glue for Xilinx EHCI core on the of_platform bus
6  *
7  * Copyright (c) 2009 Xilinx, Inc.
8  *
9  * Based on "ehci-ppc-of.c" by Valentine Barshak <vbarshak@ru.mvista.com>
10  * and "ehci-ppc-soc.c" by Stefan Roese <sr@denx.de>
11  * and "ohci-ppc-of.c" by Sylvain Munaut <tnt@246tNt.com>
12  */
13 
14 #include <linux/err.h>
15 #include <linux/signal.h>
16 
17 #include <linux/of.h>
18 #include <linux/of_platform.h>
19 #include <linux/of_address.h>
20 #include <linux/of_irq.h>
21 
22 /**
23  * ehci_xilinx_port_handed_over - hand the port out if failed to enable it
24  * @hcd:	Pointer to the usb_hcd device to which the host controller bound
25  * @portnum:Port number to which the device is attached.
26  *
27  * This function is used as a place to tell the user that the Xilinx USB host
28  * controller does support LS devices. And in an HS only configuration, it
29  * does not support FS devices either. It is hoped that this can help a
30  * confused user.
31  *
32  * There are cases when the host controller fails to enable the port due to,
33  * for example, insufficient power that can be supplied to the device from
34  * the USB bus. In those cases, the messages printed here are not helpful.
35  */
36 static int ehci_xilinx_port_handed_over(struct usb_hcd *hcd, int portnum)
37 {
38 	dev_warn(hcd->self.controller, "port %d cannot be enabled\n", portnum);
39 	if (hcd->has_tt) {
40 		dev_warn(hcd->self.controller,
41 			"Maybe you have connected a low speed device?\n");
42 
43 		dev_warn(hcd->self.controller,
44 			"We do not support low speed devices\n");
45 	} else {
46 		dev_warn(hcd->self.controller,
47 			"Maybe your device is not a high speed device?\n");
48 		dev_warn(hcd->self.controller,
49 			"The USB host controller does not support full speed "
50 			"nor low speed devices\n");
51 		dev_warn(hcd->self.controller,
52 			"You can reconfigure the host controller to have "
53 			"full speed support\n");
54 	}
55 
56 	return 0;
57 }
58 
59 
60 static const struct hc_driver ehci_xilinx_of_hc_driver = {
61 	.description		= hcd_name,
62 	.product_desc		= "OF EHCI",
63 	.hcd_priv_size		= sizeof(struct ehci_hcd),
64 
65 	/*
66 	 * generic hardware linkage
67 	 */
68 	.irq			= ehci_irq,
69 	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH,
70 
71 	/*
72 	 * basic lifecycle operations
73 	 */
74 	.reset			= ehci_setup,
75 	.start			= ehci_run,
76 	.stop			= ehci_stop,
77 	.shutdown		= ehci_shutdown,
78 
79 	/*
80 	 * managing i/o requests and associated device resources
81 	 */
82 	.urb_enqueue		= ehci_urb_enqueue,
83 	.urb_dequeue		= ehci_urb_dequeue,
84 	.endpoint_disable	= ehci_endpoint_disable,
85 	.endpoint_reset		= ehci_endpoint_reset,
86 
87 	/*
88 	 * scheduling support
89 	 */
90 	.get_frame_number	= ehci_get_frame,
91 
92 	/*
93 	 * root hub support
94 	 */
95 	.hub_status_data	= ehci_hub_status_data,
96 	.hub_control		= ehci_hub_control,
97 #ifdef	CONFIG_PM
98 	.bus_suspend		= ehci_bus_suspend,
99 	.bus_resume		= ehci_bus_resume,
100 #endif
101 	.relinquish_port	= NULL,
102 	.port_handed_over	= ehci_xilinx_port_handed_over,
103 
104 	.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
105 };
106 
107 /**
108  * ehci_hcd_xilinx_of_probe - Probe method for the USB host controller
109  * @op:		pointer to the platform_device bound to the host controller
110  *
111  * This function requests resources and sets up appropriate properties for the
112  * host controller. Because the Xilinx USB host controller can be configured
113  * as HS only or HS/FS only, it checks the configuration in the device tree
114  * entry, and sets an appropriate value for hcd->has_tt.
115  */
116 static int ehci_hcd_xilinx_of_probe(struct platform_device *op)
117 {
118 	struct device_node *dn = op->dev.of_node;
119 	struct usb_hcd *hcd;
120 	struct ehci_hcd	*ehci;
121 	struct resource res;
122 	int irq;
123 	int rv;
124 	int *value;
125 
126 	if (usb_disabled())
127 		return -ENODEV;
128 
129 	dev_dbg(&op->dev, "initializing XILINX-OF USB Controller\n");
130 
131 	rv = of_address_to_resource(dn, 0, &res);
132 	if (rv)
133 		return rv;
134 
135 	hcd = usb_create_hcd(&ehci_xilinx_of_hc_driver, &op->dev,
136 				"XILINX-OF USB");
137 	if (!hcd)
138 		return -ENOMEM;
139 
140 	hcd->rsrc_start = res.start;
141 	hcd->rsrc_len = resource_size(&res);
142 
143 	irq = irq_of_parse_and_map(dn, 0);
144 	if (!irq) {
145 		dev_err(&op->dev, "%s: irq_of_parse_and_map failed\n",
146 			__FILE__);
147 		rv = -EBUSY;
148 		goto err_irq;
149 	}
150 
151 	hcd->regs = devm_ioremap_resource(&op->dev, &res);
152 	if (IS_ERR(hcd->regs)) {
153 		rv = PTR_ERR(hcd->regs);
154 		goto err_irq;
155 	}
156 
157 	ehci = hcd_to_ehci(hcd);
158 
159 	/* This core always has big-endian register interface and uses
160 	 * big-endian memory descriptors.
161 	 */
162 	ehci->big_endian_mmio = 1;
163 	ehci->big_endian_desc = 1;
164 
165 	/* Check whether the FS support option is selected in the hardware.
166 	 */
167 	value = (int *)of_get_property(dn, "xlnx,support-usb-fs", NULL);
168 	if (value && (*value == 1)) {
169 		ehci_dbg(ehci, "USB host controller supports FS devices\n");
170 		hcd->has_tt = 1;
171 	} else {
172 		ehci_dbg(ehci,
173 			"USB host controller is HS only\n");
174 		hcd->has_tt = 0;
175 	}
176 
177 	/* Debug registers are at the first 0x100 region
178 	 */
179 	ehci->caps = hcd->regs + 0x100;
180 
181 	rv = usb_add_hcd(hcd, irq, 0);
182 	if (rv == 0) {
183 		device_wakeup_enable(hcd->self.controller);
184 		return 0;
185 	}
186 
187 err_irq:
188 	usb_put_hcd(hcd);
189 
190 	return rv;
191 }
192 
193 /**
194  * ehci_hcd_xilinx_of_remove - shutdown hcd and release resources
195  * @op:		pointer to platform_device structure that is to be removed
196  *
197  * Remove the hcd structure, and release resources that has been requested
198  * during probe.
199  */
200 static int ehci_hcd_xilinx_of_remove(struct platform_device *op)
201 {
202 	struct usb_hcd *hcd = platform_get_drvdata(op);
203 
204 	dev_dbg(&op->dev, "stopping XILINX-OF USB Controller\n");
205 
206 	usb_remove_hcd(hcd);
207 
208 	usb_put_hcd(hcd);
209 
210 	return 0;
211 }
212 
213 static const struct of_device_id ehci_hcd_xilinx_of_match[] = {
214 		{.compatible = "xlnx,xps-usb-host-1.00.a",},
215 	{},
216 };
217 MODULE_DEVICE_TABLE(of, ehci_hcd_xilinx_of_match);
218 
219 static struct platform_driver ehci_hcd_xilinx_of_driver = {
220 	.probe		= ehci_hcd_xilinx_of_probe,
221 	.remove		= ehci_hcd_xilinx_of_remove,
222 	.shutdown	= usb_hcd_platform_shutdown,
223 	.driver = {
224 		.name = "xilinx-of-ehci",
225 		.of_match_table = ehci_hcd_xilinx_of_match,
226 	},
227 };
228