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
42static 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 */
100void 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
125static 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
168static 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
182static 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};
188MODULE_DEVICE_TABLE(of, fotg210_of_match);
189#endif
190
191static 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
200static 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}
206module_init(fotg210_init);
207
208static 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}
214module_exit(fotg210_cleanup);
215
216MODULE_AUTHOR("Yuan-Hsin Chen, Feng-Hsin Chiang");
217MODULE_LICENSE("GPL");
218MODULE_DESCRIPTION("FOTG210 Dual Role Controller Driver");
219