1/*
  2 * OMAP OTG controller driver
  3 *
  4 * Based on code from tahvo-usb.c and isp1301_omap.c drivers.
  5 *
  6 * Copyright (C) 2005-2006 Nokia Corporation
  7 * Copyright (C) 2004 Texas Instruments
  8 * Copyright (C) 2004 David Brownell
  9 *
 10 * This file is subject to the terms and conditions of the GNU General
 11 * Public License. See the file "COPYING" in the main directory of this
 12 * archive for more details.
 13 *
 14 * This program is distributed in the hope that it will be useful,
 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 17 * GNU General Public License for more details.
 18 */
 19
 20#include <linux/io.h>
 21#include <linux/err.h>
 22#include <linux/extcon.h>
 23#include <linux/kernel.h>
 24#include <linux/module.h>
 25#include <linux/interrupt.h>
 26#include <linux/platform_device.h>
 27#include <linux/platform_data/usb-omap1.h>
 28
 29struct otg_device {
 30	void __iomem			*base;
 31	bool				id;
 32	bool				vbus;
 33	struct extcon_specific_cable_nb	vbus_dev;
 34	struct extcon_specific_cable_nb	id_dev;
 35	struct notifier_block		vbus_nb;
 36	struct notifier_block		id_nb;
 37};
 38
 39#define OMAP_OTG_CTRL		0x0c
 40#define OMAP_OTG_ASESSVLD	(1 << 20)
 41#define OMAP_OTG_BSESSEND	(1 << 19)
 42#define OMAP_OTG_BSESSVLD	(1 << 18)
 43#define OMAP_OTG_VBUSVLD	(1 << 17)
 44#define OMAP_OTG_ID		(1 << 16)
 45#define OMAP_OTG_XCEIV_OUTPUTS \
 46	(OMAP_OTG_ASESSVLD | OMAP_OTG_BSESSEND | OMAP_OTG_BSESSVLD | \
 47	 OMAP_OTG_VBUSVLD  | OMAP_OTG_ID)
 48
 49static void omap_otg_ctrl(struct otg_device *otg_dev, u32 outputs)
 50{
 51	u32 l;
 52
 53	l = readl(otg_dev->base + OMAP_OTG_CTRL);
 54	l &= ~OMAP_OTG_XCEIV_OUTPUTS;
 55	l |= outputs;
 56	writel(l, otg_dev->base + OMAP_OTG_CTRL);
 57}
 58
 59static void omap_otg_set_mode(struct otg_device *otg_dev)
 60{
 61	if (!otg_dev->id && otg_dev->vbus)
 62		/* Set B-session valid. */
 63		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSVLD);
 64	else if (otg_dev->vbus)
 65		/* Set A-session valid. */
 66		omap_otg_ctrl(otg_dev, OMAP_OTG_ASESSVLD);
 67	else if (!otg_dev->id)
 68		/* Set B-session end to indicate no VBUS. */
 69		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSEND);
 70}
 71
 72static int omap_otg_id_notifier(struct notifier_block *nb,
 73				unsigned long event, void *ptr)
 74{
 75	struct otg_device *otg_dev = container_of(nb, struct otg_device, id_nb);
 76
 77	otg_dev->id = event;
 78	omap_otg_set_mode(otg_dev);
 79
 80	return NOTIFY_DONE;
 81}
 82
 83static int omap_otg_vbus_notifier(struct notifier_block *nb,
 84				  unsigned long event, void *ptr)
 85{
 86	struct otg_device *otg_dev = container_of(nb, struct otg_device,
 87						  vbus_nb);
 88
 89	otg_dev->vbus = event;
 90	omap_otg_set_mode(otg_dev);
 91
 92	return NOTIFY_DONE;
 93}
 94
 95static int omap_otg_probe(struct platform_device *pdev)
 96{
 97	const struct omap_usb_config *config = pdev->dev.platform_data;
 98	struct otg_device *otg_dev;
 99	struct extcon_dev *extcon;
100	int ret;
101	u32 rev;
102
103	if (!config || !config->extcon)
104		return -ENODEV;
105
106	extcon = extcon_get_extcon_dev(config->extcon);
107	if (!extcon)
108		return -EPROBE_DEFER;
109
110	otg_dev = devm_kzalloc(&pdev->dev, sizeof(*otg_dev), GFP_KERNEL);
111	if (!otg_dev)
112		return -ENOMEM;
113
114	otg_dev->base = devm_ioremap_resource(&pdev->dev, &pdev->resource[0]);
115	if (IS_ERR(otg_dev->base))
116		return PTR_ERR(otg_dev->base);
117
118	otg_dev->id_nb.notifier_call = omap_otg_id_notifier;
119	otg_dev->vbus_nb.notifier_call = omap_otg_vbus_notifier;
120
121	ret = extcon_register_interest(&otg_dev->id_dev, config->extcon,
122				       "USB-HOST", &otg_dev->id_nb);
123	if (ret)
124		return ret;
125
126	ret = extcon_register_interest(&otg_dev->vbus_dev, config->extcon,
127				       "USB", &otg_dev->vbus_nb);
128	if (ret) {
129		extcon_unregister_interest(&otg_dev->id_dev);
130		return ret;
131	}
132
133	otg_dev->id = extcon_get_cable_state(extcon, "USB-HOST");
134	otg_dev->vbus = extcon_get_cable_state(extcon, "USB");
135	omap_otg_set_mode(otg_dev);
136
137	rev = readl(otg_dev->base);
138
139	dev_info(&pdev->dev,
140		 "OMAP USB OTG controller rev %d.%d (%s, id=%d, vbus=%d)\n",
141		 (rev >> 4) & 0xf, rev & 0xf, config->extcon, otg_dev->id,
142		 otg_dev->vbus);
143
144	return 0;
145}
146
147static int omap_otg_remove(struct platform_device *pdev)
148{
149	struct otg_device *otg_dev = platform_get_drvdata(pdev);
150
151	extcon_unregister_interest(&otg_dev->id_dev);
152	extcon_unregister_interest(&otg_dev->vbus_dev);
153
154	return 0;
155}
156
157static struct platform_driver omap_otg_driver = {
158	.probe		= omap_otg_probe,
159	.remove		= omap_otg_remove,
160	.driver		= {
161		.owner	= THIS_MODULE,
162		.name	= "omap_otg",
163	},
164};
165module_platform_driver(omap_otg_driver);
166
167MODULE_DESCRIPTION("OMAP USB OTG controller driver");
168MODULE_LICENSE("GPL");
169MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");