1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Driver for EHCI UHP on Atmel chips
4 *
5 * Copyright (C) 2009 Atmel Corporation,
6 * Nicolas Ferre <nicolas.ferre@atmel.com>
7 *
8 * Based on various ehci-*.c drivers
9 */
10
11 #include <linux/clk.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/io.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_platform.h>
18 #include <linux/platform_device.h>
19 #include <linux/usb.h>
20 #include <linux/usb/hcd.h>
21
22 #include "ehci.h"
23
24 #define DRIVER_DESC "EHCI Atmel driver"
25
26 static const char hcd_name[] = "ehci-atmel";
27
28 /* interface and function clocks */
29 #define hcd_to_atmel_ehci_priv(h) \
30 ((struct atmel_ehci_priv *)hcd_to_ehci(h)->priv)
31
32 struct atmel_ehci_priv {
33 struct clk *iclk;
34 struct clk *uclk;
35 bool clocked;
36 };
37
38 static struct hc_driver __read_mostly ehci_atmel_hc_driver;
39
40 static const struct ehci_driver_overrides ehci_atmel_drv_overrides __initconst = {
41 .extra_priv_size = sizeof(struct atmel_ehci_priv),
42 };
43
44 /*-------------------------------------------------------------------------*/
45
atmel_start_clock(struct atmel_ehci_priv * atmel_ehci)46 static void atmel_start_clock(struct atmel_ehci_priv *atmel_ehci)
47 {
48 if (atmel_ehci->clocked)
49 return;
50
51 clk_prepare_enable(atmel_ehci->uclk);
52 clk_prepare_enable(atmel_ehci->iclk);
53 atmel_ehci->clocked = true;
54 }
55
atmel_stop_clock(struct atmel_ehci_priv * atmel_ehci)56 static void atmel_stop_clock(struct atmel_ehci_priv *atmel_ehci)
57 {
58 if (!atmel_ehci->clocked)
59 return;
60
61 clk_disable_unprepare(atmel_ehci->iclk);
62 clk_disable_unprepare(atmel_ehci->uclk);
63 atmel_ehci->clocked = false;
64 }
65
atmel_start_ehci(struct platform_device * pdev)66 static void atmel_start_ehci(struct platform_device *pdev)
67 {
68 struct usb_hcd *hcd = platform_get_drvdata(pdev);
69 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
70
71 dev_dbg(&pdev->dev, "start\n");
72 atmel_start_clock(atmel_ehci);
73 }
74
atmel_stop_ehci(struct platform_device * pdev)75 static void atmel_stop_ehci(struct platform_device *pdev)
76 {
77 struct usb_hcd *hcd = platform_get_drvdata(pdev);
78 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
79
80 dev_dbg(&pdev->dev, "stop\n");
81 atmel_stop_clock(atmel_ehci);
82 }
83
84 /*-------------------------------------------------------------------------*/
85
ehci_atmel_drv_probe(struct platform_device * pdev)86 static int ehci_atmel_drv_probe(struct platform_device *pdev)
87 {
88 struct usb_hcd *hcd;
89 const struct hc_driver *driver = &ehci_atmel_hc_driver;
90 struct resource *res;
91 struct ehci_hcd *ehci;
92 struct atmel_ehci_priv *atmel_ehci;
93 int irq;
94 int retval;
95
96 if (usb_disabled())
97 return -ENODEV;
98
99 pr_debug("Initializing Atmel-SoC USB Host Controller\n");
100
101 irq = platform_get_irq(pdev, 0);
102 if (irq <= 0) {
103 retval = -ENODEV;
104 goto fail_create_hcd;
105 }
106
107 /* Right now device-tree probed devices don't get dma_mask set.
108 * Since shared usb code relies on it, set it here for now.
109 * Once we have dma capability bindings this can go away.
110 */
111 retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
112 if (retval)
113 goto fail_create_hcd;
114
115 hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
116 if (!hcd) {
117 retval = -ENOMEM;
118 goto fail_create_hcd;
119 }
120 atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
121
122 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
123 hcd->regs = devm_ioremap_resource(&pdev->dev, res);
124 if (IS_ERR(hcd->regs)) {
125 retval = PTR_ERR(hcd->regs);
126 goto fail_request_resource;
127 }
128
129 hcd->rsrc_start = res->start;
130 hcd->rsrc_len = resource_size(res);
131
132 atmel_ehci->iclk = devm_clk_get(&pdev->dev, "ehci_clk");
133 if (IS_ERR(atmel_ehci->iclk)) {
134 dev_err(&pdev->dev, "Error getting interface clock\n");
135 retval = -ENOENT;
136 goto fail_request_resource;
137 }
138
139 atmel_ehci->uclk = devm_clk_get(&pdev->dev, "usb_clk");
140 if (IS_ERR(atmel_ehci->uclk)) {
141 dev_err(&pdev->dev, "failed to get uclk\n");
142 retval = PTR_ERR(atmel_ehci->uclk);
143 goto fail_request_resource;
144 }
145
146 ehci = hcd_to_ehci(hcd);
147 /* registers start at offset 0x0 */
148 ehci->caps = hcd->regs;
149
150 atmel_start_ehci(pdev);
151
152 retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
153 if (retval)
154 goto fail_add_hcd;
155 device_wakeup_enable(hcd->self.controller);
156
157 return retval;
158
159 fail_add_hcd:
160 atmel_stop_ehci(pdev);
161 fail_request_resource:
162 usb_put_hcd(hcd);
163 fail_create_hcd:
164 dev_err(&pdev->dev, "init %s fail, %d\n",
165 dev_name(&pdev->dev), retval);
166
167 return retval;
168 }
169
ehci_atmel_drv_remove(struct platform_device * pdev)170 static int ehci_atmel_drv_remove(struct platform_device *pdev)
171 {
172 struct usb_hcd *hcd = platform_get_drvdata(pdev);
173
174 usb_remove_hcd(hcd);
175 usb_put_hcd(hcd);
176
177 atmel_stop_ehci(pdev);
178
179 return 0;
180 }
181
ehci_atmel_drv_suspend(struct device * dev)182 static int __maybe_unused ehci_atmel_drv_suspend(struct device *dev)
183 {
184 struct usb_hcd *hcd = dev_get_drvdata(dev);
185 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
186 int ret;
187
188 ret = ehci_suspend(hcd, false);
189 if (ret)
190 return ret;
191
192 atmel_stop_clock(atmel_ehci);
193 return 0;
194 }
195
ehci_atmel_drv_resume(struct device * dev)196 static int __maybe_unused ehci_atmel_drv_resume(struct device *dev)
197 {
198 struct usb_hcd *hcd = dev_get_drvdata(dev);
199 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
200
201 atmel_start_clock(atmel_ehci);
202 ehci_resume(hcd, false);
203 return 0;
204 }
205
206 #ifdef CONFIG_OF
207 static const struct of_device_id atmel_ehci_dt_ids[] = {
208 { .compatible = "atmel,at91sam9g45-ehci" },
209 { /* sentinel */ }
210 };
211
212 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
213 #endif
214
215 static SIMPLE_DEV_PM_OPS(ehci_atmel_pm_ops, ehci_atmel_drv_suspend,
216 ehci_atmel_drv_resume);
217
218 static struct platform_driver ehci_atmel_driver = {
219 .probe = ehci_atmel_drv_probe,
220 .remove = ehci_atmel_drv_remove,
221 .shutdown = usb_hcd_platform_shutdown,
222 .driver = {
223 .name = "atmel-ehci",
224 .pm = &ehci_atmel_pm_ops,
225 .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
226 },
227 };
228
ehci_atmel_init(void)229 static int __init ehci_atmel_init(void)
230 {
231 if (usb_disabled())
232 return -ENODEV;
233
234 pr_info("%s: " DRIVER_DESC "\n", hcd_name);
235 ehci_init_driver(&ehci_atmel_hc_driver, &ehci_atmel_drv_overrides);
236 return platform_driver_register(&ehci_atmel_driver);
237 }
238 module_init(ehci_atmel_init);
239
ehci_atmel_cleanup(void)240 static void __exit ehci_atmel_cleanup(void)
241 {
242 platform_driver_unregister(&ehci_atmel_driver);
243 }
244 module_exit(ehci_atmel_cleanup);
245
246 MODULE_DESCRIPTION(DRIVER_DESC);
247 MODULE_ALIAS("platform:atmel-ehci");
248 MODULE_AUTHOR("Nicolas Ferre");
249 MODULE_LICENSE("GPL");
250