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mxs-phy.c
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1 /*
2  * Copyright 2012 Freescale Semiconductor, Inc.
3  * Copyright (C) 2012 Marek Vasut <[email protected]>
4  * on behalf of DENX Software Engineering GmbH
5  *
6  * The code contained herein is licensed under the GNU General Public
7  * License. You may obtain a copy of the GNU General Public License
8  * Version 2 or later at the following locations:
9  *
10  * http://www.opensource.org/licenses/gpl-license.html
11  * http://www.gnu.org/copyleft/gpl.html
12  */
13 
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/platform_device.h>
17 #include <linux/clk.h>
18 #include <linux/usb/otg.h>
19 #include <linux/stmp_device.h>
20 #include <linux/delay.h>
21 #include <linux/err.h>
22 #include <linux/io.h>
23 #include <linux/workqueue.h>
24 
25 #define DRIVER_NAME "mxs_phy"
26 
27 #define HW_USBPHY_PWD 0x00
28 #define HW_USBPHY_CTRL 0x30
29 #define HW_USBPHY_CTRL_SET 0x34
30 #define HW_USBPHY_CTRL_CLR 0x38
31 
32 #define BM_USBPHY_CTRL_SFTRST BIT(31)
33 #define BM_USBPHY_CTRL_CLKGATE BIT(30)
34 #define BM_USBPHY_CTRL_ENUTMILEVEL3 BIT(15)
35 #define BM_USBPHY_CTRL_ENUTMILEVEL2 BIT(14)
36 #define BM_USBPHY_CTRL_ENHOSTDISCONDETECT BIT(1)
37 
38 /*
39  * Amount of delay in miliseconds to safely enable ENHOSTDISCONDETECT bit
40  * so that connection and reset processing can be completed for the root hub.
41  */
42 #define MXY_PHY_ENHOSTDISCONDETECT_DELAY 250
43 
44 struct mxs_phy {
45  struct usb_phy phy;
46  struct clk *clk;
48 };
49 
50 #define to_mxs_phy(p) container_of((p), struct mxs_phy, phy)
51 
52 static void mxs_phy_hw_init(struct mxs_phy *mxs_phy)
53 {
54  void __iomem *base = mxs_phy->phy.io_priv;
55 
57 
58  /* Power up the PHY */
59  writel_relaxed(0, base + HW_USBPHY_PWD);
60 
61  /* enable FS/LS device */
62  writel_relaxed(BM_USBPHY_CTRL_ENUTMILEVEL2 |
64  base + HW_USBPHY_CTRL_SET);
65 }
66 
67 static int mxs_phy_init(struct usb_phy *phy)
68 {
69  struct mxs_phy *mxs_phy = to_mxs_phy(phy);
70 
71  clk_prepare_enable(mxs_phy->clk);
72  mxs_phy_hw_init(mxs_phy);
74 
75  return 0;
76 }
77 
78 static void mxs_phy_shutdown(struct usb_phy *phy)
79 {
80  struct mxs_phy *mxs_phy = to_mxs_phy(phy);
81 
82  writel_relaxed(BM_USBPHY_CTRL_CLKGATE,
84 
85  clk_disable_unprepare(mxs_phy->clk);
86 }
87 
88 static void mxs_phy_enhostdiscondetect_delay(struct work_struct *ws)
89 {
90  struct mxs_phy *mxs_phy = container_of(ws, struct mxs_phy,
92 
93  /* Enable HOSTDISCONDETECT after delay. */
94  dev_dbg(mxs_phy->phy.dev, "Setting ENHOSTDISCONDETECT\n");
95  writel_relaxed(BM_USBPHY_CTRL_ENHOSTDISCONDETECT,
96  mxs_phy->phy.io_priv + HW_USBPHY_CTRL_SET);
97 }
98 
99 static int mxs_phy_on_connect(struct usb_phy *phy, int port)
100 {
101  struct mxs_phy *mxs_phy = to_mxs_phy(phy);
102 
103  dev_dbg(phy->dev, "Connect on port %d\n", port);
104 
105  mxs_phy_hw_init(mxs_phy);
106 
107  /*
108  * Delay enabling ENHOSTDISCONDETECT so that connection and
109  * reset processing can be completed for the root hub.
110  */
111  dev_dbg(phy->dev, "Delaying setting ENHOSTDISCONDETECT\n");
113  mxs_phy_enhostdiscondetect_delay);
116 
117  return 0;
118 }
119 
120 static int mxs_phy_on_disconnect(struct usb_phy *phy, int port)
121 {
122  dev_dbg(phy->dev, "Disconnect on port %d\n", port);
123 
124  /* No need to delay before clearing ENHOSTDISCONDETECT. */
125  dev_dbg(phy->dev, "Clearing ENHOSTDISCONDETECT\n");
126  writel_relaxed(BM_USBPHY_CTRL_ENHOSTDISCONDETECT,
127  phy->io_priv + HW_USBPHY_CTRL_CLR);
128 
129  return 0;
130 }
131 
132 static int mxs_phy_probe(struct platform_device *pdev)
133 {
134  struct resource *res;
135  void __iomem *base;
136  struct clk *clk;
137  struct mxs_phy *mxs_phy;
138 
139  res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
140  if (!res) {
141  dev_err(&pdev->dev, "can't get device resources\n");
142  return -ENOENT;
143  }
144 
145  base = devm_request_and_ioremap(&pdev->dev, res);
146  if (!base)
147  return -EBUSY;
148 
149  clk = devm_clk_get(&pdev->dev, NULL);
150  if (IS_ERR(clk)) {
151  dev_err(&pdev->dev,
152  "can't get the clock, err=%ld", PTR_ERR(clk));
153  return PTR_ERR(clk);
154  }
155 
156  mxs_phy = devm_kzalloc(&pdev->dev, sizeof(*mxs_phy), GFP_KERNEL);
157  if (!mxs_phy) {
158  dev_err(&pdev->dev, "Failed to allocate USB PHY structure!\n");
159  return -ENOMEM;
160  }
161 
162  mxs_phy->phy.io_priv = base;
163  mxs_phy->phy.dev = &pdev->dev;
164  mxs_phy->phy.label = DRIVER_NAME;
165  mxs_phy->phy.init = mxs_phy_init;
166  mxs_phy->phy.shutdown = mxs_phy_shutdown;
167  mxs_phy->phy.notify_connect = mxs_phy_on_connect;
168  mxs_phy->phy.notify_disconnect = mxs_phy_on_disconnect;
169 
170  ATOMIC_INIT_NOTIFIER_HEAD(&mxs_phy->phy.notifier);
171 
172  mxs_phy->clk = clk;
173 
174  platform_set_drvdata(pdev, &mxs_phy->phy);
175 
176  return 0;
177 }
178 
179 static int __devexit mxs_phy_remove(struct platform_device *pdev)
180 {
181  platform_set_drvdata(pdev, NULL);
182 
183  return 0;
184 }
185 
186 static const struct of_device_id mxs_phy_dt_ids[] = {
187  { .compatible = "fsl,imx23-usbphy", },
188  { /* sentinel */ }
189 };
190 MODULE_DEVICE_TABLE(of, mxs_phy_dt_ids);
191 
192 static struct platform_driver mxs_phy_driver = {
193  .probe = mxs_phy_probe,
194  .remove = __devexit_p(mxs_phy_remove),
195  .driver = {
196  .name = DRIVER_NAME,
197  .owner = THIS_MODULE,
198  .of_match_table = mxs_phy_dt_ids,
199  },
200 };
201 
202 static int __init mxs_phy_module_init(void)
203 {
204  return platform_driver_register(&mxs_phy_driver);
205 }
206 postcore_initcall(mxs_phy_module_init);
207 
208 static void __exit mxs_phy_module_exit(void)
209 {
210  platform_driver_unregister(&mxs_phy_driver);
211 }
212 module_exit(mxs_phy_module_exit);
213 
214 MODULE_ALIAS("platform:mxs-usb-phy");
215 MODULE_AUTHOR("Marek Vasut <[email protected]>");
216 MODULE_AUTHOR("Richard Zhao <[email protected]>");
217 MODULE_DESCRIPTION("Freescale MXS USB PHY driver");
218 MODULE_LICENSE("GPL");