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 * @fotg: pointer to a private fotg210 object
 99 * @enable: true to enable VBUS, false to disable VBUS
100 */
101void fotg210_vbus(struct fotg210 *fotg, bool enable)
102{
103	u32 mask;
104	u32 val;
105	int ret;
106
107	switch (fotg->port) {
108	case GEMINI_PORT_0:
109		mask = GEMINI_MISC_USB0_VBUS_ON;
110		val = enable ? GEMINI_MISC_USB0_VBUS_ON : 0;
111		break;
112	case GEMINI_PORT_1:
113		mask = GEMINI_MISC_USB1_VBUS_ON;
114		val = enable ? GEMINI_MISC_USB1_VBUS_ON : 0;
115		break;
116	default:
117		return;
118	}
119	ret = regmap_update_bits(fotg->map, GEMINI_GLOBAL_MISC_CTRL, mask, val);
120	if (ret)
121		dev_err(fotg->dev, "failed to %s VBUS\n",
122			enable ? "enable" : "disable");
123	dev_info(fotg->dev, "%s: %s VBUS\n", __func__, enable ? "enable" : "disable");
124}
125
126static int fotg210_probe(struct platform_device *pdev)
127{
128	struct device *dev = &pdev->dev;
129	enum usb_dr_mode mode;
130	struct fotg210 *fotg;
131	u32 val;
132	int ret;
133
134	fotg = devm_kzalloc(dev, sizeof(*fotg), GFP_KERNEL);
135	if (!fotg)
136		return -ENOMEM;
137	fotg->dev = dev;
138
139	fotg->base = devm_platform_get_and_ioremap_resource(pdev, 0, &fotg->res);
140	if (IS_ERR(fotg->base))
141		return PTR_ERR(fotg->base);
142
143	fotg->pclk = devm_clk_get_optional_enabled(dev, "PCLK");
144	if (IS_ERR(fotg->pclk))
145		return PTR_ERR(fotg->pclk);
146
147	mode = usb_get_dr_mode(dev);
148
149	if (of_device_is_compatible(dev->of_node, "cortina,gemini-usb")) {
150		ret = fotg210_gemini_init(fotg, fotg->res, mode);
151		if (ret)
152			return ret;
153	}
154
155	val = readl(fotg->base + FOTG210_RR);
156	if (mode == USB_DR_MODE_PERIPHERAL) {
157		if (!(val & FOTG210_RR_CROLE))
158			dev_err(dev, "block not in device role\n");
159		ret = fotg210_udc_probe(pdev, fotg);
160	} else {
161		if (val & FOTG210_RR_CROLE)
162			dev_err(dev, "block not in host role\n");
163		ret = fotg210_hcd_probe(pdev, fotg);
164	}
165
166	return ret;
167}
168
169static void fotg210_remove(struct platform_device *pdev)
170{
171	struct device *dev = &pdev->dev;
172	enum usb_dr_mode mode;
173
174	mode = usb_get_dr_mode(dev);
175
176	if (mode == USB_DR_MODE_PERIPHERAL)
177		fotg210_udc_remove(pdev);
178	else
179		fotg210_hcd_remove(pdev);
180}
181
182#ifdef CONFIG_OF
183static const struct of_device_id fotg210_of_match[] = {
184	{ .compatible = "faraday,fotg200" },
185	{ .compatible = "faraday,fotg210" },
186	/* TODO: can we also handle FUSB220? */
187	{},
188};
189MODULE_DEVICE_TABLE(of, fotg210_of_match);
190#endif
191
192static struct platform_driver fotg210_driver = {
193	.driver = {
194		.name   = "fotg210",
195		.of_match_table = of_match_ptr(fotg210_of_match),
196	},
197	.probe  = fotg210_probe,
198	.remove = fotg210_remove,
199};
200
201static int __init fotg210_init(void)
202{
203	if (IS_ENABLED(CONFIG_USB_FOTG210_HCD) && !usb_disabled())
204		fotg210_hcd_init();
205	return platform_driver_register(&fotg210_driver);
206}
207module_init(fotg210_init);
208
209static void __exit fotg210_cleanup(void)
210{
211	platform_driver_unregister(&fotg210_driver);
212	if (IS_ENABLED(CONFIG_USB_FOTG210_HCD))
213		fotg210_hcd_cleanup();
214}
215module_exit(fotg210_cleanup);
216
217MODULE_AUTHOR("Yuan-Hsin Chen, Feng-Hsin Chiang");
218MODULE_LICENSE("GPL");
219MODULE_DESCRIPTION("FOTG210 Dual Role Controller Driver");