tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Driver for EHCI UHP on Atmel chips
3 *
4 * Copyright (C) 2009 Atmel Corporation,
5 * Nicolas Ferre <nicolas.ferre@atmel.com>
6 *
7 * Based on various ehci-*.c drivers
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file COPYING in the main directory of this archive for
11 * more details.
12 */
13
14#include <linux/clk.h>
15#include <linux/dma-mapping.h>
16#include <linux/io.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/of_platform.h>
21#include <linux/platform_device.h>
22#include <linux/usb.h>
23#include <linux/usb/hcd.h>
24
25#include "ehci.h"
26
27#define DRIVER_DESC "EHCI Atmel driver"
28
29static const char hcd_name[] = "ehci-atmel";
30static struct hc_driver __read_mostly ehci_atmel_hc_driver;
31
32/* interface and function clocks */
33static struct clk *iclk, *fclk, *uclk;
34static int clocked;
35
36/*-------------------------------------------------------------------------*/
37
38static void atmel_start_clock(void)
39{
40 if (IS_ENABLED(CONFIG_COMMON_CLK)) {
41 clk_set_rate(uclk, 48000000);
42 clk_prepare_enable(uclk);
43 }
44 clk_prepare_enable(iclk);
45 clk_prepare_enable(fclk);
46 clocked = 1;
47}
48
49static void atmel_stop_clock(void)
50{
51 clk_disable_unprepare(fclk);
52 clk_disable_unprepare(iclk);
53 if (IS_ENABLED(CONFIG_COMMON_CLK))
54 clk_disable_unprepare(uclk);
55 clocked = 0;
56}
57
58static void atmel_start_ehci(struct platform_device *pdev)
59{
60 dev_dbg(&pdev->dev, "start\n");
61 atmel_start_clock();
62}
63
64static void atmel_stop_ehci(struct platform_device *pdev)
65{
66 dev_dbg(&pdev->dev, "stop\n");
67 atmel_stop_clock();
68}
69
70/*-------------------------------------------------------------------------*/
71
72static int ehci_atmel_drv_probe(struct platform_device *pdev)
73{
74 struct usb_hcd *hcd;
75 const struct hc_driver *driver = &ehci_atmel_hc_driver;
76 struct resource *res;
77 struct ehci_hcd *ehci;
78 int irq;
79 int retval;
80
81 if (usb_disabled())
82 return -ENODEV;
83
84 pr_debug("Initializing Atmel-SoC USB Host Controller\n");
85
86 irq = platform_get_irq(pdev, 0);
87 if (irq <= 0) {
88 dev_err(&pdev->dev,
89 "Found HC with no IRQ. Check %s setup!\n",
90 dev_name(&pdev->dev));
91 retval = -ENODEV;
92 goto fail_create_hcd;
93 }
94
95 /* Right now device-tree probed devices don't get dma_mask set.
96 * Since shared usb code relies on it, set it here for now.
97 * Once we have dma capability bindings this can go away.
98 */
99 retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
100 if (retval)
101 goto fail_create_hcd;
102
103 hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
104 if (!hcd) {
105 retval = -ENOMEM;
106 goto fail_create_hcd;
107 }
108
109 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
110 hcd->regs = devm_ioremap_resource(&pdev->dev, res);
111 if (IS_ERR(hcd->regs)) {
112 retval = PTR_ERR(hcd->regs);
113 goto fail_request_resource;
114 }
115
116 hcd->rsrc_start = res->start;
117 hcd->rsrc_len = resource_size(res);
118
119 iclk = devm_clk_get(&pdev->dev, "ehci_clk");
120 if (IS_ERR(iclk)) {
121 dev_err(&pdev->dev, "Error getting interface clock\n");
122 retval = -ENOENT;
123 goto fail_request_resource;
124 }
125 fclk = devm_clk_get(&pdev->dev, "uhpck");
126 if (IS_ERR(fclk)) {
127 dev_err(&pdev->dev, "Error getting function clock\n");
128 retval = -ENOENT;
129 goto fail_request_resource;
130 }
131 if (IS_ENABLED(CONFIG_COMMON_CLK)) {
132 uclk = devm_clk_get(&pdev->dev, "usb_clk");
133 if (IS_ERR(uclk)) {
134 dev_err(&pdev->dev, "failed to get uclk\n");
135 retval = PTR_ERR(uclk);
136 goto fail_request_resource;
137 }
138 }
139
140 ehci = hcd_to_ehci(hcd);
141 /* registers start at offset 0x0 */
142 ehci->caps = hcd->regs;
143
144 atmel_start_ehci(pdev);
145
146 retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
147 if (retval)
148 goto fail_add_hcd;
149 device_wakeup_enable(hcd->self.controller);
150
151 return retval;
152
153fail_add_hcd:
154 atmel_stop_ehci(pdev);
155fail_request_resource:
156 usb_put_hcd(hcd);
157fail_create_hcd:
158 dev_err(&pdev->dev, "init %s fail, %d\n",
159 dev_name(&pdev->dev), retval);
160
161 return retval;
162}
163
164static int ehci_atmel_drv_remove(struct platform_device *pdev)
165{
166 struct usb_hcd *hcd = platform_get_drvdata(pdev);
167
168 usb_remove_hcd(hcd);
169 usb_put_hcd(hcd);
170
171 atmel_stop_ehci(pdev);
172 fclk = iclk = NULL;
173
174 return 0;
175}
176
177#ifdef CONFIG_OF
178static const struct of_device_id atmel_ehci_dt_ids[] = {
179 { .compatible = "atmel,at91sam9g45-ehci" },
180 { /* sentinel */ }
181};
182
183MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
184#endif
185
186static struct platform_driver ehci_atmel_driver = {
187 .probe = ehci_atmel_drv_probe,
188 .remove = ehci_atmel_drv_remove,
189 .shutdown = usb_hcd_platform_shutdown,
190 .driver = {
191 .name = "atmel-ehci",
192 .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
193 },
194};
195
196static int __init ehci_atmel_init(void)
197{
198 if (usb_disabled())
199 return -ENODEV;
200
201 pr_info("%s: " DRIVER_DESC "\n", hcd_name);
202 ehci_init_driver(&ehci_atmel_hc_driver, NULL);
203 return platform_driver_register(&ehci_atmel_driver);
204}
205module_init(ehci_atmel_init);
206
207static void __exit ehci_atmel_cleanup(void)
208{
209 platform_driver_unregister(&ehci_atmel_driver);
210}
211module_exit(ehci_atmel_cleanup);
212
213MODULE_DESCRIPTION(DRIVER_DESC);
214MODULE_ALIAS("platform:atmel-ehci");
215MODULE_AUTHOR("Nicolas Ferre");
216MODULE_LICENSE("GPL");