fotg210-core.c

  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/string_choices.h>
 17#include <linux/usb.h>
 18#include <linux/usb/otg.h>
 19
 20#include "fotg210.h"
 21
 22/* Role Register 0x80 */
 23#define FOTG210_RR			0x80
 24#define FOTG210_RR_ID			BIT(21) /* 1 = B-device, 0 = A-device */
 25#define FOTG210_RR_CROLE		BIT(20) /* 1 = device, 0 = host */
 26
 27/*
 28 * Gemini-specific initialization function, only executed on the
 29 * Gemini SoC using the global misc control register.
 30 *
 31 * The gemini USB blocks are connected to either Mini-A (host mode) or
 32 * Mini-B (peripheral mode) plugs. There is no role switch support on the
 33 * Gemini SoC, just either-or.
 34 */
 35#define GEMINI_GLOBAL_MISC_CTRL		0x30
 36#define GEMINI_MISC_USB0_WAKEUP		BIT(14)
 37#define GEMINI_MISC_USB1_WAKEUP		BIT(15)
 38#define GEMINI_MISC_USB0_VBUS_ON	BIT(22)
 39#define GEMINI_MISC_USB1_VBUS_ON	BIT(23)
 40#define GEMINI_MISC_USB0_MINI_B		BIT(29)
 41#define GEMINI_MISC_USB1_MINI_B		BIT(30)
 42
 43static int fotg210_gemini_init(struct fotg210 *fotg, struct resource *res,
 44			       enum usb_dr_mode mode)
 45{
 46	struct device *dev = fotg->dev;
 47	struct device_node *np = dev->of_node;
 48	struct regmap *map;
 49	bool wakeup;
 50	u32 mask, val;
 51	int ret;
 52
 53	map = syscon_regmap_lookup_by_phandle(np, "syscon");
 54	if (IS_ERR(map))
 55		return dev_err_probe(dev, PTR_ERR(map), "no syscon\n");
 56	fotg->map = map;
 57	wakeup = of_property_read_bool(np, "wakeup-source");
 58
 59	/*
 60	 * Figure out if this is USB0 or USB1 by simply checking the
 61	 * physical base address.
 62	 */
 63	mask = 0;
 64	if (res->start == 0x69000000) {
 65		fotg->port = GEMINI_PORT_1;
 66		mask = GEMINI_MISC_USB1_VBUS_ON | GEMINI_MISC_USB1_MINI_B |
 67			GEMINI_MISC_USB1_WAKEUP;
 68		if (mode == USB_DR_MODE_HOST)
 69			val = GEMINI_MISC_USB1_VBUS_ON;
 70		else
 71			val = GEMINI_MISC_USB1_MINI_B;
 72		if (wakeup)
 73			val |= GEMINI_MISC_USB1_WAKEUP;
 74	} else {
 75		fotg->port = GEMINI_PORT_0;
 76		mask = GEMINI_MISC_USB0_VBUS_ON | GEMINI_MISC_USB0_MINI_B |
 77			GEMINI_MISC_USB0_WAKEUP;
 78		if (mode == USB_DR_MODE_HOST)
 79			val = GEMINI_MISC_USB0_VBUS_ON;
 80		else
 81			val = GEMINI_MISC_USB0_MINI_B;
 82		if (wakeup)
 83			val |= GEMINI_MISC_USB0_WAKEUP;
 84	}
 85
 86	ret = regmap_update_bits(map, GEMINI_GLOBAL_MISC_CTRL, mask, val);
 87	if (ret) {
 88		dev_err(dev, "failed to initialize Gemini PHY\n");
 89		return ret;
 90	}
 91
 92	dev_info(dev, "initialized Gemini PHY in %s mode\n",
 93		 (mode == USB_DR_MODE_HOST) ? "host" : "gadget");
 94	return 0;
 95}
 96
 97/**
 98 * fotg210_vbus() - Called by gadget driver to enable/disable VBUS
 99 * @fotg: pointer to a private fotg210 object
100 * @enable: true to enable VBUS, false to disable VBUS
101 */
102void fotg210_vbus(struct fotg210 *fotg, bool enable)
103{
104	u32 mask;
105	u32 val;
106	int ret;
107
108	switch (fotg->port) {
109	case GEMINI_PORT_0:
110		mask = GEMINI_MISC_USB0_VBUS_ON;
111		val = enable ? GEMINI_MISC_USB0_VBUS_ON : 0;
112		break;
113	case GEMINI_PORT_1:
114		mask = GEMINI_MISC_USB1_VBUS_ON;
115		val = enable ? GEMINI_MISC_USB1_VBUS_ON : 0;
116		break;
117	default:
118		return;
119	}
120	ret = regmap_update_bits(fotg->map, GEMINI_GLOBAL_MISC_CTRL, mask, val);
121	if (ret)
122		dev_err(fotg->dev, "failed to %s VBUS\n",
123			str_enable_disable(enable));
124	dev_info(fotg->dev, "%s: %s VBUS\n", __func__, str_enable_disable(enable));
125}
126
127static int fotg210_probe(struct platform_device *pdev)
128{
129	struct device *dev = &pdev->dev;
130	enum usb_dr_mode mode;
131	struct fotg210 *fotg;
132	u32 val;
133	int ret;
134
135	fotg = devm_kzalloc(dev, sizeof(*fotg), GFP_KERNEL);
136	if (!fotg)
137		return -ENOMEM;
138	fotg->dev = dev;
139
140	fotg->base = devm_platform_get_and_ioremap_resource(pdev, 0, &fotg->res);
141	if (IS_ERR(fotg->base))
142		return PTR_ERR(fotg->base);
143
144	fotg->pclk = devm_clk_get_optional_enabled(dev, "PCLK");
145	if (IS_ERR(fotg->pclk))
146		return PTR_ERR(fotg->pclk);
147
148	mode = usb_get_dr_mode(dev);
149
150	if (of_device_is_compatible(dev->of_node, "cortina,gemini-usb")) {
151		ret = fotg210_gemini_init(fotg, fotg->res, mode);
152		if (ret)
153			return ret;
154	}
155
156	val = readl(fotg->base + FOTG210_RR);
157	if (mode == USB_DR_MODE_PERIPHERAL) {
158		if (!(val & FOTG210_RR_CROLE))
159			dev_err(dev, "block not in device role\n");
160		ret = fotg210_udc_probe(pdev, fotg);
161	} else {
162		if (val & FOTG210_RR_CROLE)
163			dev_err(dev, "block not in host role\n");
164		ret = fotg210_hcd_probe(pdev, fotg);
165	}
166
167	return ret;
168}
169
170static void fotg210_remove(struct platform_device *pdev)
171{
172	struct device *dev = &pdev->dev;
173	enum usb_dr_mode mode;
174
175	mode = usb_get_dr_mode(dev);
176
177	if (mode == USB_DR_MODE_PERIPHERAL)
178		fotg210_udc_remove(pdev);
179	else
180		fotg210_hcd_remove(pdev);
181}
182
183#ifdef CONFIG_OF
184static const struct of_device_id fotg210_of_match[] = {
185	{ .compatible = "faraday,fotg200" },
186	{ .compatible = "faraday,fotg210" },
187	/* TODO: can we also handle FUSB220? */
188	{},
189};
190MODULE_DEVICE_TABLE(of, fotg210_of_match);
191#endif
192
193static struct platform_driver fotg210_driver = {
194	.driver = {
195		.name   = "fotg210",
196		.of_match_table = of_match_ptr(fotg210_of_match),
197	},
198	.probe  = fotg210_probe,
199	.remove = fotg210_remove,
200};
201
202static int __init fotg210_init(void)
203{
204	if (IS_ENABLED(CONFIG_USB_FOTG210_HCD) && !usb_disabled())
205		fotg210_hcd_init();
206	return platform_driver_register(&fotg210_driver);
207}
208module_init(fotg210_init);
209
210static void __exit fotg210_cleanup(void)
211{
212	platform_driver_unregister(&fotg210_driver);
213	if (IS_ENABLED(CONFIG_USB_FOTG210_HCD))
214		fotg210_hcd_cleanup();
215}
216module_exit(fotg210_cleanup);
217
218MODULE_AUTHOR("Yuan-Hsin Chen, Feng-Hsin Chiang");
219MODULE_LICENSE("GPL");
220MODULE_DESCRIPTION("FOTG210 Dual Role Controller Driver");