xref: /openbmc/linux/drivers/usb/host/ehci-atmel.c (revision 9470114d)
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 #define EHCI_INSNREG(index)			((index) * 4 + 0x90)
29 #define EHCI_INSNREG08_HSIC_EN			BIT(2)
30 
31 /* interface and function clocks */
32 #define hcd_to_atmel_ehci_priv(h) \
33 	((struct atmel_ehci_priv *)hcd_to_ehci(h)->priv)
34 
35 struct atmel_ehci_priv {
36 	struct clk *iclk;
37 	struct clk *uclk;
38 	bool clocked;
39 };
40 
41 static struct hc_driver __read_mostly ehci_atmel_hc_driver;
42 
43 static const struct ehci_driver_overrides ehci_atmel_drv_overrides __initconst = {
44 	.extra_priv_size = sizeof(struct atmel_ehci_priv),
45 };
46 
47 /*-------------------------------------------------------------------------*/
48 
49 static void atmel_start_clock(struct atmel_ehci_priv *atmel_ehci)
50 {
51 	if (atmel_ehci->clocked)
52 		return;
53 
54 	clk_prepare_enable(atmel_ehci->uclk);
55 	clk_prepare_enable(atmel_ehci->iclk);
56 	atmel_ehci->clocked = true;
57 }
58 
59 static void atmel_stop_clock(struct atmel_ehci_priv *atmel_ehci)
60 {
61 	if (!atmel_ehci->clocked)
62 		return;
63 
64 	clk_disable_unprepare(atmel_ehci->iclk);
65 	clk_disable_unprepare(atmel_ehci->uclk);
66 	atmel_ehci->clocked = false;
67 }
68 
69 static void atmel_start_ehci(struct platform_device *pdev)
70 {
71 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
72 	struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
73 
74 	dev_dbg(&pdev->dev, "start\n");
75 	atmel_start_clock(atmel_ehci);
76 }
77 
78 static void atmel_stop_ehci(struct platform_device *pdev)
79 {
80 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
81 	struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
82 
83 	dev_dbg(&pdev->dev, "stop\n");
84 	atmel_stop_clock(atmel_ehci);
85 }
86 
87 /*-------------------------------------------------------------------------*/
88 
89 static int ehci_atmel_drv_probe(struct platform_device *pdev)
90 {
91 	struct usb_hcd *hcd;
92 	const struct hc_driver *driver = &ehci_atmel_hc_driver;
93 	struct resource *res;
94 	struct ehci_hcd *ehci;
95 	struct atmel_ehci_priv *atmel_ehci;
96 	int irq;
97 	int retval;
98 
99 	if (usb_disabled())
100 		return -ENODEV;
101 
102 	pr_debug("Initializing Atmel-SoC USB Host Controller\n");
103 
104 	irq = platform_get_irq(pdev, 0);
105 	if (irq < 0) {
106 		retval = irq;
107 		goto fail_create_hcd;
108 	}
109 
110 	/* Right now device-tree probed devices don't get dma_mask set.
111 	 * Since shared usb code relies on it, set it here for now.
112 	 * Once we have dma capability bindings this can go away.
113 	 */
114 	retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
115 	if (retval)
116 		goto fail_create_hcd;
117 
118 	hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
119 	if (!hcd) {
120 		retval = -ENOMEM;
121 		goto fail_create_hcd;
122 	}
123 	atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
124 
125 	hcd->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
126 	if (IS_ERR(hcd->regs)) {
127 		retval = PTR_ERR(hcd->regs);
128 		goto fail_request_resource;
129 	}
130 
131 	hcd->rsrc_start = res->start;
132 	hcd->rsrc_len = resource_size(res);
133 
134 	atmel_ehci->iclk = devm_clk_get(&pdev->dev, "ehci_clk");
135 	if (IS_ERR(atmel_ehci->iclk)) {
136 		dev_err(&pdev->dev, "Error getting interface clock\n");
137 		retval = -ENOENT;
138 		goto fail_request_resource;
139 	}
140 
141 	atmel_ehci->uclk = devm_clk_get(&pdev->dev, "usb_clk");
142 	if (IS_ERR(atmel_ehci->uclk)) {
143 		dev_err(&pdev->dev, "failed to get uclk\n");
144 		retval = PTR_ERR(atmel_ehci->uclk);
145 		goto fail_request_resource;
146 	}
147 
148 	ehci = hcd_to_ehci(hcd);
149 	/* registers start at offset 0x0 */
150 	ehci->caps = hcd->regs;
151 
152 	atmel_start_ehci(pdev);
153 
154 	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
155 	if (retval)
156 		goto fail_add_hcd;
157 	device_wakeup_enable(hcd->self.controller);
158 
159 	if (of_usb_get_phy_mode(pdev->dev.of_node) == USBPHY_INTERFACE_MODE_HSIC)
160 		writel(EHCI_INSNREG08_HSIC_EN, hcd->regs + EHCI_INSNREG(8));
161 
162 	return retval;
163 
164 fail_add_hcd:
165 	atmel_stop_ehci(pdev);
166 fail_request_resource:
167 	usb_put_hcd(hcd);
168 fail_create_hcd:
169 	dev_err(&pdev->dev, "init %s fail, %d\n",
170 		dev_name(&pdev->dev), retval);
171 
172 	return retval;
173 }
174 
175 static void ehci_atmel_drv_remove(struct platform_device *pdev)
176 {
177 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
178 
179 	usb_remove_hcd(hcd);
180 	usb_put_hcd(hcd);
181 
182 	atmel_stop_ehci(pdev);
183 }
184 
185 static int __maybe_unused ehci_atmel_drv_suspend(struct device *dev)
186 {
187 	struct usb_hcd *hcd = dev_get_drvdata(dev);
188 	struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
189 	int ret;
190 
191 	ret = ehci_suspend(hcd, false);
192 	if (ret)
193 		return ret;
194 
195 	atmel_stop_clock(atmel_ehci);
196 	return 0;
197 }
198 
199 static int __maybe_unused ehci_atmel_drv_resume(struct device *dev)
200 {
201 	struct usb_hcd *hcd = dev_get_drvdata(dev);
202 	struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd);
203 
204 	atmel_start_clock(atmel_ehci);
205 	ehci_resume(hcd, false);
206 	return 0;
207 }
208 
209 #ifdef CONFIG_OF
210 static const struct of_device_id atmel_ehci_dt_ids[] = {
211 	{ .compatible = "atmel,at91sam9g45-ehci" },
212 	{ /* sentinel */ }
213 };
214 
215 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
216 #endif
217 
218 static SIMPLE_DEV_PM_OPS(ehci_atmel_pm_ops, ehci_atmel_drv_suspend,
219 					ehci_atmel_drv_resume);
220 
221 static struct platform_driver ehci_atmel_driver = {
222 	.probe		= ehci_atmel_drv_probe,
223 	.remove_new	= ehci_atmel_drv_remove,
224 	.shutdown	= usb_hcd_platform_shutdown,
225 	.driver		= {
226 		.name	= "atmel-ehci",
227 		.pm	= &ehci_atmel_pm_ops,
228 		.of_match_table	= of_match_ptr(atmel_ehci_dt_ids),
229 	},
230 };
231 
232 static int __init ehci_atmel_init(void)
233 {
234 	if (usb_disabled())
235 		return -ENODEV;
236 
237 	ehci_init_driver(&ehci_atmel_hc_driver, &ehci_atmel_drv_overrides);
238 	return platform_driver_register(&ehci_atmel_driver);
239 }
240 module_init(ehci_atmel_init);
241 
242 static void __exit ehci_atmel_cleanup(void)
243 {
244 	platform_driver_unregister(&ehci_atmel_driver);
245 }
246 module_exit(ehci_atmel_cleanup);
247 
248 MODULE_DESCRIPTION(DRIVER_DESC);
249 MODULE_ALIAS("platform:atmel-ehci");
250 MODULE_AUTHOR("Nicolas Ferre");
251 MODULE_LICENSE("GPL");
252