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 */
 38static 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
 60static 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 */
118static 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
189err_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 */
204static void 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
215static const struct of_device_id ehci_hcd_xilinx_of_match[] = {
216		{.compatible = "xlnx,xps-usb-host-1.00.a",},
217	{},
218};
219MODULE_DEVICE_TABLE(of, ehci_hcd_xilinx_of_match);
220
221static struct platform_driver ehci_hcd_xilinx_of_driver = {
222	.probe		= ehci_hcd_xilinx_of_probe,
223	.remove_new	= ehci_hcd_xilinx_of_remove,
224	.shutdown	= usb_hcd_platform_shutdown,
225	.driver = {
226		.name = "xilinx-of-ehci",
227		.of_match_table = ehci_hcd_xilinx_of_match,
228	},
229};