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  * Return: Always return 0
37  */
ehci_xilinx_port_handed_over(struct usb_hcd * hcd,int portnum)38 static int ehci_xilinx_port_handed_over(struct usb_hcd *hcd, int portnum)
39 {
40 	dev_warn(hcd->self.controller, "port %d cannot be enabled\n", portnum);
41 	if (hcd->has_tt) {
42 		dev_warn(hcd->self.controller,
43 			"Maybe you have connected a low speed device?\n");
44 
45 		dev_warn(hcd->self.controller,
46 			"We do not support low speed devices\n");
47 	} else {
48 		dev_warn(hcd->self.controller,
49 			"Maybe your device is not a high speed device?\n");
50 		dev_warn(hcd->self.controller,
51 			"The USB host controller does not support full speed nor low speed devices\n");
52 		dev_warn(hcd->self.controller,
53 			"You can reconfigure the host controller to have 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  * Return: zero on success, negative error code otherwise
117  */
ehci_hcd_xilinx_of_probe(struct platform_device * op)118 static int ehci_hcd_xilinx_of_probe(struct platform_device *op)
119 {
120 	struct device_node *dn = op->dev.of_node;
121 	struct usb_hcd *hcd;
122 	struct ehci_hcd	*ehci;
123 	struct resource res;
124 	int irq;
125 	int rv;
126 	int *value;
127 
128 	if (usb_disabled())
129 		return -ENODEV;
130 
131 	dev_dbg(&op->dev, "initializing XILINX-OF USB Controller\n");
132 
133 	rv = of_address_to_resource(dn, 0, &res);
134 	if (rv)
135 		return rv;
136 
137 	hcd = usb_create_hcd(&ehci_xilinx_of_hc_driver, &op->dev,
138 				"XILINX-OF USB");
139 	if (!hcd)
140 		return -ENOMEM;
141 
142 	hcd->rsrc_start = res.start;
143 	hcd->rsrc_len = resource_size(&res);
144 
145 	irq = irq_of_parse_and_map(dn, 0);
146 	if (!irq) {
147 		dev_err(&op->dev, "%s: irq_of_parse_and_map failed\n",
148 			__FILE__);
149 		rv = -EBUSY;
150 		goto err_irq;
151 	}
152 
153 	hcd->regs = devm_ioremap_resource(&op->dev, &res);
154 	if (IS_ERR(hcd->regs)) {
155 		rv = PTR_ERR(hcd->regs);
156 		goto err_irq;
157 	}
158 
159 	ehci = hcd_to_ehci(hcd);
160 
161 	/* This core always has big-endian register interface and uses
162 	 * big-endian memory descriptors.
163 	 */
164 	ehci->big_endian_mmio = 1;
165 	ehci->big_endian_desc = 1;
166 
167 	/* Check whether the FS support option is selected in the hardware.
168 	 */
169 	value = (int *)of_get_property(dn, "xlnx,support-usb-fs", NULL);
170 	if (value && (*value == 1)) {
171 		ehci_dbg(ehci, "USB host controller supports FS devices\n");
172 		hcd->has_tt = 1;
173 	} else {
174 		ehci_dbg(ehci,
175 			"USB host controller is HS only\n");
176 		hcd->has_tt = 0;
177 	}
178 
179 	/* Debug registers are at the first 0x100 region
180 	 */
181 	ehci->caps = hcd->regs + 0x100;
182 
183 	rv = usb_add_hcd(hcd, irq, 0);
184 	if (rv == 0) {
185 		device_wakeup_enable(hcd->self.controller);
186 		return 0;
187 	}
188 
189 err_irq:
190 	usb_put_hcd(hcd);
191 
192 	return rv;
193 }
194 
195 /**
196  * ehci_hcd_xilinx_of_remove - shutdown hcd and release resources
197  * @op:		pointer to platform_device structure that is to be removed
198  *
199  * Remove the hcd structure, and release resources that has been requested
200  * during probe.
201  *
202  * Return: Always return 0
203  */
ehci_hcd_xilinx_of_remove(struct platform_device * op)204 static int ehci_hcd_xilinx_of_remove(struct platform_device *op)
205 {
206 	struct usb_hcd *hcd = platform_get_drvdata(op);
207 
208 	dev_dbg(&op->dev, "stopping XILINX-OF USB Controller\n");
209 
210 	usb_remove_hcd(hcd);
211 
212 	usb_put_hcd(hcd);
213 
214 	return 0;
215 }
216 
217 static const struct of_device_id ehci_hcd_xilinx_of_match[] = {
218 		{.compatible = "xlnx,xps-usb-host-1.00.a",},
219 	{},
220 };
221 MODULE_DEVICE_TABLE(of, ehci_hcd_xilinx_of_match);
222 
223 static struct platform_driver ehci_hcd_xilinx_of_driver = {
224 	.probe		= ehci_hcd_xilinx_of_probe,
225 	.remove		= ehci_hcd_xilinx_of_remove,
226 	.shutdown	= usb_hcd_platform_shutdown,
227 	.driver = {
228 		.name = "xilinx-of-ehci",
229 		.of_match_table = ehci_hcd_xilinx_of_match,
230 	},
231 };
232