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/clk.h>
10 #include <linux/device.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16 #include <linux/usb.h>
17 #include <linux/usb/otg.h>
18 
19 #include "fotg210.h"
20 
21 /* Role Register 0x80 */
22 #define FOTG210_RR			0x80
23 #define FOTG210_RR_ID			BIT(21) /* 1 = B-device, 0 = A-device */
24 #define FOTG210_RR_CROLE		BIT(20) /* 1 = device, 0 = host */
25 
26 /*
27  * Gemini-specific initialization function, only executed on the
28  * Gemini SoC using the global misc control register.
29  *
30  * The gemini USB blocks are connected to either Mini-A (host mode) or
31  * Mini-B (peripheral mode) plugs. There is no role switch support on the
32  * Gemini SoC, just either-or.
33  */
34 #define GEMINI_GLOBAL_MISC_CTRL		0x30
35 #define GEMINI_MISC_USB0_WAKEUP		BIT(14)
36 #define GEMINI_MISC_USB1_WAKEUP		BIT(15)
37 #define GEMINI_MISC_USB0_VBUS_ON	BIT(22)
38 #define GEMINI_MISC_USB1_VBUS_ON	BIT(23)
39 #define GEMINI_MISC_USB0_MINI_B		BIT(29)
40 #define GEMINI_MISC_USB1_MINI_B		BIT(30)
41 
42 static int fotg210_gemini_init(struct fotg210 *fotg, struct resource *res,
43 			       enum usb_dr_mode mode)
44 {
45 	struct device *dev = fotg->dev;
46 	struct device_node *np = dev->of_node;
47 	struct regmap *map;
48 	bool wakeup;
49 	u32 mask, val;
50 	int ret;
51 
52 	map = syscon_regmap_lookup_by_phandle(np, "syscon");
53 	if (IS_ERR(map))
54 		return dev_err_probe(dev, PTR_ERR(map), "no syscon\n");
55 	fotg->map = map;
56 	wakeup = of_property_read_bool(np, "wakeup-source");
57 
58 	/*
59 	 * Figure out if this is USB0 or USB1 by simply checking the
60 	 * physical base address.
61 	 */
62 	mask = 0;
63 	if (res->start == 0x69000000) {
64 		fotg->port = GEMINI_PORT_1;
65 		mask = GEMINI_MISC_USB1_VBUS_ON | GEMINI_MISC_USB1_MINI_B |
66 			GEMINI_MISC_USB1_WAKEUP;
67 		if (mode == USB_DR_MODE_HOST)
68 			val = GEMINI_MISC_USB1_VBUS_ON;
69 		else
70 			val = GEMINI_MISC_USB1_MINI_B;
71 		if (wakeup)
72 			val |= GEMINI_MISC_USB1_WAKEUP;
73 	} else {
74 		fotg->port = GEMINI_PORT_0;
75 		mask = GEMINI_MISC_USB0_VBUS_ON | GEMINI_MISC_USB0_MINI_B |
76 			GEMINI_MISC_USB0_WAKEUP;
77 		if (mode == USB_DR_MODE_HOST)
78 			val = GEMINI_MISC_USB0_VBUS_ON;
79 		else
80 			val = GEMINI_MISC_USB0_MINI_B;
81 		if (wakeup)
82 			val |= GEMINI_MISC_USB0_WAKEUP;
83 	}
84 
85 	ret = regmap_update_bits(map, GEMINI_GLOBAL_MISC_CTRL, mask, val);
86 	if (ret) {
87 		dev_err(dev, "failed to initialize Gemini PHY\n");
88 		return ret;
89 	}
90 
91 	dev_info(dev, "initialized Gemini PHY in %s mode\n",
92 		 (mode == USB_DR_MODE_HOST) ? "host" : "gadget");
93 	return 0;
94 }
95 
96 /**
97  * fotg210_vbus() - Called by gadget driver to enable/disable VBUS
98  * @enable: true to enable VBUS, false to disable VBUS
99  */
100 void fotg210_vbus(struct fotg210 *fotg, bool enable)
101 {
102 	u32 mask;
103 	u32 val;
104 	int ret;
105 
106 	switch (fotg->port) {
107 	case GEMINI_PORT_0:
108 		mask = GEMINI_MISC_USB0_VBUS_ON;
109 		val = enable ? GEMINI_MISC_USB0_VBUS_ON : 0;
110 		break;
111 	case GEMINI_PORT_1:
112 		mask = GEMINI_MISC_USB1_VBUS_ON;
113 		val = enable ? GEMINI_MISC_USB1_VBUS_ON : 0;
114 		break;
115 	default:
116 		return;
117 	}
118 	ret = regmap_update_bits(fotg->map, GEMINI_GLOBAL_MISC_CTRL, mask, val);
119 	if (ret)
120 		dev_err(fotg->dev, "failed to %s VBUS\n",
121 			enable ? "enable" : "disable");
122 	dev_info(fotg->dev, "%s: %s VBUS\n", __func__, enable ? "enable" : "disable");
123 }
124 
125 static int fotg210_probe(struct platform_device *pdev)
126 {
127 	struct device *dev = &pdev->dev;
128 	enum usb_dr_mode mode;
129 	struct fotg210 *fotg;
130 	u32 val;
131 	int ret;
132 
133 	fotg = devm_kzalloc(dev, sizeof(*fotg), GFP_KERNEL);
134 	if (!fotg)
135 		return -ENOMEM;
136 	fotg->dev = dev;
137 
138 	fotg->base = devm_platform_get_and_ioremap_resource(pdev, 0, &fotg->res);
139 	if (IS_ERR(fotg->base))
140 		return PTR_ERR(fotg->base);
141 
142 	fotg->pclk = devm_clk_get_optional_enabled(dev, "PCLK");
143 	if (IS_ERR(fotg->pclk))
144 		return PTR_ERR(fotg->pclk);
145 
146 	mode = usb_get_dr_mode(dev);
147 
148 	if (of_device_is_compatible(dev->of_node, "cortina,gemini-usb")) {
149 		ret = fotg210_gemini_init(fotg, fotg->res, mode);
150 		if (ret)
151 			return ret;
152 	}
153 
154 	val = readl(fotg->base + FOTG210_RR);
155 	if (mode == USB_DR_MODE_PERIPHERAL) {
156 		if (!(val & FOTG210_RR_CROLE))
157 			dev_err(dev, "block not in device role\n");
158 		ret = fotg210_udc_probe(pdev, fotg);
159 	} else {
160 		if (val & FOTG210_RR_CROLE)
161 			dev_err(dev, "block not in host role\n");
162 		ret = fotg210_hcd_probe(pdev, fotg);
163 	}
164 
165 	return ret;
166 }
167 
168 static void fotg210_remove(struct platform_device *pdev)
169 {
170 	struct device *dev = &pdev->dev;
171 	enum usb_dr_mode mode;
172 
173 	mode = usb_get_dr_mode(dev);
174 
175 	if (mode == USB_DR_MODE_PERIPHERAL)
176 		fotg210_udc_remove(pdev);
177 	else
178 		fotg210_hcd_remove(pdev);
179 }
180 
181 #ifdef CONFIG_OF
182 static const struct of_device_id fotg210_of_match[] = {
183 	{ .compatible = "faraday,fotg200" },
184 	{ .compatible = "faraday,fotg210" },
185 	/* TODO: can we also handle FUSB220? */
186 	{},
187 };
188 MODULE_DEVICE_TABLE(of, fotg210_of_match);
189 #endif
190 
191 static struct platform_driver fotg210_driver = {
192 	.driver = {
193 		.name   = "fotg210",
194 		.of_match_table = of_match_ptr(fotg210_of_match),
195 	},
196 	.probe  = fotg210_probe,
197 	.remove_new = fotg210_remove,
198 };
199 
200 static int __init fotg210_init(void)
201 {
202 	if (IS_ENABLED(CONFIG_USB_FOTG210_HCD) && !usb_disabled())
203 		fotg210_hcd_init();
204 	return platform_driver_register(&fotg210_driver);
205 }
206 module_init(fotg210_init);
207 
208 static void __exit fotg210_cleanup(void)
209 {
210 	platform_driver_unregister(&fotg210_driver);
211 	if (IS_ENABLED(CONFIG_USB_FOTG210_HCD))
212 		fotg210_hcd_cleanup();
213 }
214 module_exit(fotg210_cleanup);
215 
216 MODULE_AUTHOR("Yuan-Hsin Chen, Feng-Hsin Chiang");
217 MODULE_LICENSE("GPL");
218 MODULE_DESCRIPTION("FOTG210 Dual Role Controller Driver");
219