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 #include <linux/usb/phy.h>
22 #include <linux/usb/of.h>
23 
24 #include "ehci.h"
25 
26 #define DRIVER_DESC "EHCI Atmel driver"
27 
28 static const char hcd_name[] = "ehci-atmel";
29 
30 #define EHCI_INSNREG(index)			((index) * 4 + 0x90)
31 #define EHCI_INSNREG08_HSIC_EN			BIT(2)
32 
33 /* interface and function clocks */
34 #define hcd_to_atmel_ehci_priv(h) \
35 	((struct atmel_ehci_priv *)hcd_to_ehci(h)->priv)
36 
37 struct atmel_ehci_priv {
38 	struct clk *iclk;
39 	struct clk *uclk;
40 	bool clocked;
41 };
42 
43 static struct hc_driver __read_mostly ehci_atmel_hc_driver;
44 
45 static const struct ehci_driver_overrides ehci_atmel_drv_overrides __initconst = {
46 	.extra_priv_size = sizeof(struct atmel_ehci_priv),
47 };
48 
49 /*-------------------------------------------------------------------------*/
50 
atmel_start_clock(struct atmel_ehci_priv * atmel_ehci)51 static void atmel_start_clock(struct atmel_ehci_priv *atmel_ehci)
52 {
53 	if (atmel_ehci->clocked)
54 		return;
55 
56 	clk_prepare_enable(atmel_ehci->uclk);
57 	clk_prepare_enable(atmel_ehci->iclk);
58 	atmel_ehci->clocked = true;
59 }
60 
atmel_stop_clock(struct atmel_ehci_priv * atmel_ehci)61 static void atmel_stop_clock(struct atmel_ehci_priv *atmel_ehci)
62 {
63 	if (!atmel_ehci->clocked)
64 		return;
65 
66 	clk_disable_unprepare(atmel_ehci->iclk);
67 	clk_disable_unprepare(atmel_ehci->uclk);
68 	atmel_ehci->clocked = false;
69 }
70 
atmel_start_ehci(struct platform_device * pdev)71 static void atmel_start_ehci(struct platform_device *pdev)
72 {
73 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
74 	struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
75 
76 	dev_dbg(&pdev->dev, "start\n");
77 	atmel_start_clock(atmel_ehci);
78 }
79 
atmel_stop_ehci(struct platform_device * pdev)80 static void atmel_stop_ehci(struct platform_device *pdev)
81 {
82 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
83 	struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
84 
85 	dev_dbg(&pdev->dev, "stop\n");
86 	atmel_stop_clock(atmel_ehci);
87 }
88 
89 /*-------------------------------------------------------------------------*/
90 
ehci_atmel_drv_probe(struct platform_device * pdev)91 static int ehci_atmel_drv_probe(struct platform_device *pdev)
92 {
93 	struct usb_hcd *hcd;
94 	const struct hc_driver *driver = &ehci_atmel_hc_driver;
95 	struct resource *res;
96 	struct ehci_hcd *ehci;
97 	struct atmel_ehci_priv *atmel_ehci;
98 	int irq;
99 	int retval;
100 
101 	if (usb_disabled())
102 		return -ENODEV;
103 
104 	pr_debug("Initializing Atmel-SoC USB Host Controller\n");
105 
106 	irq = platform_get_irq(pdev, 0);
107 	if (irq <= 0) {
108 		retval = -ENODEV;
109 		goto fail_create_hcd;
110 	}
111 
112 	/* Right now device-tree probed devices don't get dma_mask set.
113 	 * Since shared usb code relies on it, set it here for now.
114 	 * Once we have dma capability bindings this can go away.
115 	 */
116 	retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
117 	if (retval)
118 		goto fail_create_hcd;
119 
120 	hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
121 	if (!hcd) {
122 		retval = -ENOMEM;
123 		goto fail_create_hcd;
124 	}
125 	atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
126 
127 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
128 	hcd->regs = devm_ioremap_resource(&pdev->dev, res);
129 	if (IS_ERR(hcd->regs)) {
130 		retval = PTR_ERR(hcd->regs);
131 		goto fail_request_resource;
132 	}
133 
134 	hcd->rsrc_start = res->start;
135 	hcd->rsrc_len = resource_size(res);
136 
137 	atmel_ehci->iclk = devm_clk_get(&pdev->dev, "ehci_clk");
138 	if (IS_ERR(atmel_ehci->iclk)) {
139 		dev_err(&pdev->dev, "Error getting interface clock\n");
140 		retval = -ENOENT;
141 		goto fail_request_resource;
142 	}
143 
144 	atmel_ehci->uclk = devm_clk_get(&pdev->dev, "usb_clk");
145 	if (IS_ERR(atmel_ehci->uclk)) {
146 		dev_err(&pdev->dev, "failed to get uclk\n");
147 		retval = PTR_ERR(atmel_ehci->uclk);
148 		goto fail_request_resource;
149 	}
150 
151 	ehci = hcd_to_ehci(hcd);
152 	/* registers start at offset 0x0 */
153 	ehci->caps = hcd->regs;
154 
155 	atmel_start_ehci(pdev);
156 
157 	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
158 	if (retval)
159 		goto fail_add_hcd;
160 	device_wakeup_enable(hcd->self.controller);
161 
162 	if (of_usb_get_phy_mode(pdev->dev.of_node) == USBPHY_INTERFACE_MODE_HSIC)
163 		writel(EHCI_INSNREG08_HSIC_EN, hcd->regs + EHCI_INSNREG(8));
164 
165 	return retval;
166 
167 fail_add_hcd:
168 	atmel_stop_ehci(pdev);
169 fail_request_resource:
170 	usb_put_hcd(hcd);
171 fail_create_hcd:
172 	dev_err(&pdev->dev, "init %s fail, %d\n",
173 		dev_name(&pdev->dev), retval);
174 
175 	return retval;
176 }
177 
ehci_atmel_drv_remove(struct platform_device * pdev)178 static int ehci_atmel_drv_remove(struct platform_device *pdev)
179 {
180 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
181 
182 	usb_remove_hcd(hcd);
183 	usb_put_hcd(hcd);
184 
185 	atmel_stop_ehci(pdev);
186 
187 	return 0;
188 }
189 
ehci_atmel_drv_suspend(struct device * dev)190 static int __maybe_unused ehci_atmel_drv_suspend(struct device *dev)
191 {
192 	struct usb_hcd *hcd = dev_get_drvdata(dev);
193 	struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
194 	int ret;
195 
196 	ret = ehci_suspend(hcd, false);
197 	if (ret)
198 		return ret;
199 
200 	atmel_stop_clock(atmel_ehci);
201 	return 0;
202 }
203 
ehci_atmel_drv_resume(struct device * dev)204 static int __maybe_unused ehci_atmel_drv_resume(struct device *dev)
205 {
206 	struct usb_hcd *hcd = dev_get_drvdata(dev);
207 	struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
208 
209 	atmel_start_clock(atmel_ehci);
210 	ehci_resume(hcd, false);
211 	return 0;
212 }
213 
214 #ifdef CONFIG_OF
215 static const struct of_device_id atmel_ehci_dt_ids[] = {
216 	{ .compatible = "atmel,at91sam9g45-ehci" },
217 	{ /* sentinel */ }
218 };
219 
220 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
221 #endif
222 
223 static SIMPLE_DEV_PM_OPS(ehci_atmel_pm_ops, ehci_atmel_drv_suspend,
224 					ehci_atmel_drv_resume);
225 
226 static struct platform_driver ehci_atmel_driver = {
227 	.probe		= ehci_atmel_drv_probe,
228 	.remove		= ehci_atmel_drv_remove,
229 	.shutdown	= usb_hcd_platform_shutdown,
230 	.driver		= {
231 		.name	= "atmel-ehci",
232 		.pm	= &ehci_atmel_pm_ops,
233 		.of_match_table	= of_match_ptr(atmel_ehci_dt_ids),
234 	},
235 };
236 
ehci_atmel_init(void)237 static int __init ehci_atmel_init(void)
238 {
239 	if (usb_disabled())
240 		return -ENODEV;
241 
242 	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
243 	ehci_init_driver(&ehci_atmel_hc_driver, &ehci_atmel_drv_overrides);
244 	return platform_driver_register(&ehci_atmel_driver);
245 }
246 module_init(ehci_atmel_init);
247 
ehci_atmel_cleanup(void)248 static void __exit ehci_atmel_cleanup(void)
249 {
250 	platform_driver_unregister(&ehci_atmel_driver);
251 }
252 module_exit(ehci_atmel_cleanup);
253 
254 MODULE_DESCRIPTION(DRIVER_DESC);
255 MODULE_ALIAS("platform:atmel-ehci");
256 MODULE_AUTHOR("Nicolas Ferre");
257 MODULE_LICENSE("GPL");
258