xref: /linux/drivers/usb/fotg210/fotg210-core.c (revision f2527d8f566a45fa00ee5abd04d1c9476d4d704f)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Central probing code for the FOTG210 dual role driver
4  * We register one driver for the hardware and then we decide
5  * whether to proceed with probing the host or the peripheral
6  * driver.
7  */
8 #include <linux/bitops.h>
9 #include <linux/device.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14 #include <linux/regmap.h>
15 #include <linux/usb.h>
16 #include <linux/usb/otg.h>
17 
18 #include "fotg210.h"
19 
20 /*
21  * Gemini-specific initialization function, only executed on the
22  * Gemini SoC using the global misc control register.
23  *
24  * The gemini USB blocks are connected to either Mini-A (host mode) or
25  * Mini-B (peripheral mode) plugs. There is no role switch support on the
26  * Gemini SoC, just either-or.
27  */
28 #define GEMINI_GLOBAL_MISC_CTRL		0x30
29 #define GEMINI_MISC_USB0_WAKEUP		BIT(14)
30 #define GEMINI_MISC_USB1_WAKEUP		BIT(15)
31 #define GEMINI_MISC_USB0_VBUS_ON	BIT(22)
32 #define GEMINI_MISC_USB1_VBUS_ON	BIT(23)
33 #define GEMINI_MISC_USB0_MINI_B		BIT(29)
34 #define GEMINI_MISC_USB1_MINI_B		BIT(30)
35 
36 static int fotg210_gemini_init(struct device *dev, struct resource *res,
37 			       enum usb_dr_mode mode)
38 {
39 	struct device_node *np = dev->of_node;
40 	struct regmap *map;
41 	bool wakeup;
42 	u32 mask, val;
43 	int ret;
44 
45 	map = syscon_regmap_lookup_by_phandle(np, "syscon");
46 	if (IS_ERR(map)) {
47 		dev_err(dev, "no syscon\n");
48 		return PTR_ERR(map);
49 	}
50 	wakeup = of_property_read_bool(np, "wakeup-source");
51 
52 	/*
53 	 * Figure out if this is USB0 or USB1 by simply checking the
54 	 * physical base address.
55 	 */
56 	mask = 0;
57 	if (res->start == 0x69000000) {
58 		mask = GEMINI_MISC_USB1_VBUS_ON | GEMINI_MISC_USB1_MINI_B |
59 			GEMINI_MISC_USB1_WAKEUP;
60 		if (mode == USB_DR_MODE_HOST)
61 			val = GEMINI_MISC_USB1_VBUS_ON;
62 		else
63 			val = GEMINI_MISC_USB1_MINI_B;
64 		if (wakeup)
65 			val |= GEMINI_MISC_USB1_WAKEUP;
66 	} else {
67 		mask = GEMINI_MISC_USB0_VBUS_ON | GEMINI_MISC_USB0_MINI_B |
68 			GEMINI_MISC_USB0_WAKEUP;
69 		if (mode == USB_DR_MODE_HOST)
70 			val = GEMINI_MISC_USB0_VBUS_ON;
71 		else
72 			val = GEMINI_MISC_USB0_MINI_B;
73 		if (wakeup)
74 			val |= GEMINI_MISC_USB0_WAKEUP;
75 	}
76 
77 	ret = regmap_update_bits(map, GEMINI_GLOBAL_MISC_CTRL, mask, val);
78 	if (ret) {
79 		dev_err(dev, "failed to initialize Gemini PHY\n");
80 		return ret;
81 	}
82 
83 	dev_info(dev, "initialized Gemini PHY in %s mode\n",
84 		 (mode == USB_DR_MODE_HOST) ? "host" : "gadget");
85 	return 0;
86 }
87 
88 static int fotg210_probe(struct platform_device *pdev)
89 {
90 	struct device *dev = &pdev->dev;
91 	enum usb_dr_mode mode;
92 	int ret;
93 
94 	mode = usb_get_dr_mode(dev);
95 
96 	if (of_device_is_compatible(dev->of_node, "cortina,gemini-usb")) {
97 		struct resource *res;
98 
99 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
100 		ret = fotg210_gemini_init(dev, res, mode);
101 		if (ret)
102 			return ret;
103 	}
104 
105 	if (mode == USB_DR_MODE_PERIPHERAL)
106 		ret = fotg210_udc_probe(pdev);
107 	else
108 		ret = fotg210_hcd_probe(pdev);
109 
110 	return ret;
111 }
112 
113 static int fotg210_remove(struct platform_device *pdev)
114 {
115 	struct device *dev = &pdev->dev;
116 	enum usb_dr_mode mode;
117 
118 	mode = usb_get_dr_mode(dev);
119 
120 	if (mode == USB_DR_MODE_PERIPHERAL)
121 		fotg210_udc_remove(pdev);
122 	else
123 		fotg210_hcd_remove(pdev);
124 
125 	return 0;
126 }
127 
128 #ifdef CONFIG_OF
129 static const struct of_device_id fotg210_of_match[] = {
130 	{ .compatible = "faraday,fotg210" },
131 	{},
132 };
133 MODULE_DEVICE_TABLE(of, fotg210_of_match);
134 #endif
135 
136 static struct platform_driver fotg210_driver = {
137 	.driver = {
138 		.name   = "fotg210",
139 		.of_match_table = of_match_ptr(fotg210_of_match),
140 	},
141 	.probe  = fotg210_probe,
142 	.remove = fotg210_remove,
143 };
144 
145 static int __init fotg210_init(void)
146 {
147 	if (IS_ENABLED(CONFIG_USB_FOTG210_HCD) && !usb_disabled())
148 		fotg210_hcd_init();
149 	return platform_driver_register(&fotg210_driver);
150 }
151 module_init(fotg210_init);
152 
153 static void __exit fotg210_cleanup(void)
154 {
155 	platform_driver_unregister(&fotg210_driver);
156 	if (IS_ENABLED(CONFIG_USB_FOTG210_HCD))
157 		fotg210_hcd_cleanup();
158 }
159 module_exit(fotg210_cleanup);
160 
161 MODULE_AUTHOR("Yuan-Hsin Chen, Feng-Hsin Chiang");
162 MODULE_LICENSE("GPL");
163 MODULE_DESCRIPTION("FOTG210 Dual Role Controller Driver");
164