1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * OMAP OTG controller driver
  4 *
  5 * Based on code from tahvo-usb.c and isp1301_omap.c drivers.
  6 *
  7 * Copyright (C) 2005-2006 Nokia Corporation
  8 * Copyright (C) 2004 Texas Instruments
  9 * Copyright (C) 2004 David Brownell
 10 */
 11
 12#include <linux/io.h>
 13#include <linux/err.h>
 14#include <linux/extcon.h>
 15#include <linux/kernel.h>
 16#include <linux/module.h>
 17#include <linux/interrupt.h>
 18#include <linux/platform_device.h>
 19#include <linux/platform_data/usb-omap1.h>
 20
 21struct otg_device {
 22	void __iomem			*base;
 23	bool				id;
 24	bool				vbus;
 25	struct extcon_dev		*extcon;
 26	struct notifier_block		vbus_nb;
 27	struct notifier_block		id_nb;
 28};
 29
 30#define OMAP_OTG_CTRL		0x0c
 31#define OMAP_OTG_ASESSVLD	(1 << 20)
 32#define OMAP_OTG_BSESSEND	(1 << 19)
 33#define OMAP_OTG_BSESSVLD	(1 << 18)
 34#define OMAP_OTG_VBUSVLD	(1 << 17)
 35#define OMAP_OTG_ID		(1 << 16)
 36#define OMAP_OTG_XCEIV_OUTPUTS \
 37	(OMAP_OTG_ASESSVLD | OMAP_OTG_BSESSEND | OMAP_OTG_BSESSVLD | \
 38	 OMAP_OTG_VBUSVLD  | OMAP_OTG_ID)
 39
 40static void omap_otg_ctrl(struct otg_device *otg_dev, u32 outputs)
 41{
 42	u32 l;
 43
 44	l = readl(otg_dev->base + OMAP_OTG_CTRL);
 45	l &= ~OMAP_OTG_XCEIV_OUTPUTS;
 46	l |= outputs;
 47	writel(l, otg_dev->base + OMAP_OTG_CTRL);
 48}
 49
 50static void omap_otg_set_mode(struct otg_device *otg_dev)
 51{
 52	if (!otg_dev->id && otg_dev->vbus)
 53		/* Set B-session valid. */
 54		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSVLD);
 55	else if (otg_dev->vbus)
 56		/* Set A-session valid. */
 57		omap_otg_ctrl(otg_dev, OMAP_OTG_ASESSVLD);
 58	else if (!otg_dev->id)
 59		/* Set B-session end to indicate no VBUS. */
 60		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSEND);
 61}
 62
 63static int omap_otg_id_notifier(struct notifier_block *nb,
 64				unsigned long event, void *ptr)
 65{
 66	struct otg_device *otg_dev = container_of(nb, struct otg_device, id_nb);
 67
 68	otg_dev->id = event;
 69	omap_otg_set_mode(otg_dev);
 70
 71	return NOTIFY_DONE;
 72}
 73
 74static int omap_otg_vbus_notifier(struct notifier_block *nb,
 75				  unsigned long event, void *ptr)
 76{
 77	struct otg_device *otg_dev = container_of(nb, struct otg_device,
 78						  vbus_nb);
 79
 80	otg_dev->vbus = event;
 81	omap_otg_set_mode(otg_dev);
 82
 83	return NOTIFY_DONE;
 84}
 85
 86static int omap_otg_probe(struct platform_device *pdev)
 87{
 88	const struct omap_usb_config *config = pdev->dev.platform_data;
 89	struct otg_device *otg_dev;
 90	struct extcon_dev *extcon;
 91	int ret;
 92	u32 rev;
 93
 94	if (!config || !config->extcon)
 95		return -ENODEV;
 96
 97	extcon = extcon_get_extcon_dev(config->extcon);
 98	if (IS_ERR(extcon))
 99		return PTR_ERR(extcon);
100
101	otg_dev = devm_kzalloc(&pdev->dev, sizeof(*otg_dev), GFP_KERNEL);
102	if (!otg_dev)
103		return -ENOMEM;
104
105	otg_dev->base = devm_ioremap_resource(&pdev->dev, &pdev->resource[0]);
106	if (IS_ERR(otg_dev->base))
107		return PTR_ERR(otg_dev->base);
108
109	otg_dev->extcon = extcon;
110	otg_dev->id_nb.notifier_call = omap_otg_id_notifier;
111	otg_dev->vbus_nb.notifier_call = omap_otg_vbus_notifier;
112
113	ret = devm_extcon_register_notifier(&pdev->dev, extcon,
114					EXTCON_USB_HOST, &otg_dev->id_nb);
115	if (ret)
116		return ret;
117
118	ret = devm_extcon_register_notifier(&pdev->dev, extcon,
119					EXTCON_USB, &otg_dev->vbus_nb);
120	if (ret) {
121		return ret;
122	}
123
124	otg_dev->id = extcon_get_state(extcon, EXTCON_USB_HOST);
125	otg_dev->vbus = extcon_get_state(extcon, EXTCON_USB);
126	omap_otg_set_mode(otg_dev);
127
128	rev = readl(otg_dev->base);
129
130	dev_info(&pdev->dev,
131		 "OMAP USB OTG controller rev %d.%d (%s, id=%d, vbus=%d)\n",
132		 (rev >> 4) & 0xf, rev & 0xf, config->extcon, otg_dev->id,
133		 otg_dev->vbus);
134
135	platform_set_drvdata(pdev, otg_dev);
136
137	return 0;
138}
139
140static struct platform_driver omap_otg_driver = {
141	.probe		= omap_otg_probe,
142	.driver		= {
143		.name	= "omap_otg",
144	},
145};
146module_platform_driver(omap_otg_driver);
147
148MODULE_DESCRIPTION("OMAP USB OTG controller driver");
149MODULE_LICENSE("GPL");
150MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");