litmus-rt.git - The LITMUS^RT kernel.

/*
 * Palmas USB transceiver driver
 *
 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Author: Graeme Gregory <gg@slimlogic.co.uk>
 * Author: Kishon Vijay Abraham I <kishon@ti.com>
 *
 * Based on twl6030_usb.c
 *
 * Author: Hema HK <hemahk@ti.com>
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/mfd/palmas.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/workqueue.h>

#define USB_GPIO_DEBOUNCE_MS	20	/* ms */

static const unsigned int palmas_extcon_cable[] = {
	EXTCON_USB,
	EXTCON_USB_HOST,
	EXTCON_NONE,
};

static void palmas_usb_wakeup(struct palmas *palmas, int enable)
{
	if (enable)
		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP,
			PALMAS_USB_WAKEUP_ID_WK_UP_COMP);
	else
		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP, 0);
}

static irqreturn_t palmas_vbus_irq_handler(int irq, void *_palmas_usb)
{
	struct palmas_usb *palmas_usb = _palmas_usb;
	struct extcon_dev *edev = palmas_usb->edev;
	unsigned int vbus_line_state;

	palmas_read(palmas_usb->palmas, PALMAS_INTERRUPT_BASE,
		PALMAS_INT3_LINE_STATE, &vbus_line_state);

	if (vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS) {
		if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
			palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
			extcon_set_state_sync(edev, EXTCON_USB, true);
			dev_dbg(palmas_usb->dev, "USB cable is attached\n");
		} else {
			dev_dbg(palmas_usb->dev,
				"Spurious connect event detected\n");
		}
	} else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
		if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
			palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
			extcon_set_state_sync(edev, EXTCON_USB, false);
			dev_dbg(palmas_usb->dev, "USB cable is detached\n");
		} else {
			dev_dbg(palmas_usb->dev,
				"Spurious disconnect event detected\n");
		}
	}

	return IRQ_HANDLED;
}

static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
{
	unsigned int set, id_src;
	struct palmas_usb *palmas_usb = _palmas_usb;
	struct extcon_dev *edev = palmas_usb->edev;

	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
		PALMAS_USB_ID_INT_LATCH_SET, &set);
	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
		PALMAS_USB_ID_INT_SRC, &id_src);

	if ((set & PALMAS_USB_ID_INT_SRC_ID_GND) &&
				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
			PALMAS_USB_ID_INT_LATCH_CLR,
			PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
		extcon_set_state_sync(edev, EXTCON_USB_HOST, true);
		dev_dbg(palmas_usb->dev, "USB-HOST cable is attached\n");
	} else if ((set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) &&
				(id_src & PALMAS_USB_ID_INT_SRC_ID_FLOAT)) {
		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
			PALMAS_USB_ID_INT_LATCH_CLR,
			PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
		extcon_set_state_sync(edev, EXTCON_USB_HOST, false);
		dev_dbg(palmas_usb->dev, "USB-HOST cable is detached\n");
	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_ID) &&
				(!(set & PALMAS_USB_ID_INT_SRC_ID_GND))) {
		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
		extcon_set_state_sync(edev, EXTCON_USB_HOST, false);
		dev_dbg(palmas_usb->dev, "USB-HOST cable is detached\n");
	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_DISCONNECT) &&
				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
		extcon_set_state_sync(edev, EXTCON_USB_HOST, true);
		dev_dbg(palmas_usb->dev, " USB-HOST cable is attached\n");
	}

	return IRQ_HANDLED;
}

static void palmas_gpio_id_detect(struct work_struct *work)
{
	int id;
	struct palmas_usb *palmas_usb = container_of(to_delayed_work(work),
						     struct palmas_usb,
						     wq_detectid);
	struct extcon_dev *edev = palmas_usb->edev;

	if (!palmas_usb->id_gpiod)
		return;

	id = gpiod_get_value_cansleep(palmas_usb->id_gpiod);

	if (id) {
		extcon_set_state_sync(edev, EXTCON_USB_HOST, false);


context:
space:
mode: