Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 * Tahvo USB transceiver driver
 *
 * Copyright (C) 2005-2006 Nokia Corporation
 *
 * Parts copied from isp1301_omap.c.
 * Copyright (C) 2004 Texas Instruments
 * Copyright (C) 2004 David Brownell
 *
 * Original driver written by Juha Yrjölä, Tony Lindgren and Timo Teräs.
 * Modified for Retu/Tahvo MFD by Aaro Koskinen.
 */
 
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/usb.h>
#include <linux/extcon-provider.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/usb/otg.h>
#include <linux/mfd/retu.h>
#include <linux/usb/gadget.h>
#include <linux/platform_device.h>
 
#define DRIVER_NAME     "tahvo-usb"
 
#define TAHVO_REG_IDSR	0x02
#define TAHVO_REG_USBR	0x06
 
#define USBR_SLAVE_CONTROL	(1 << 8)
#define USBR_VPPVIO_SW		(1 << 7)
#define USBR_SPEED		(1 << 6)
#define USBR_REGOUT		(1 << 5)
#define USBR_MASTER_SW2		(1 << 4)
#define USBR_MASTER_SW1		(1 << 3)
#define USBR_SLAVE_SW		(1 << 2)
#define USBR_NSUSPEND		(1 << 1)
#define USBR_SEMODE		(1 << 0)
 
#define TAHVO_MODE_HOST		0
#define TAHVO_MODE_PERIPHERAL	1
 
struct tahvo_usb {
<------>struct platform_device	*pt_dev;
<------>struct usb_phy		phy;
<------>int			vbus_state;
<------>struct mutex		serialize;
<------>struct clk		*ick;
<------>int			irq;
<------>int			tahvo_mode;
<------>struct extcon_dev	*extcon;
};
 
static const unsigned int tahvo_cable[] = {
<------>EXTCON_USB,
<------>EXTCON_USB_HOST,
 
<------>EXTCON_NONE,
};
 
static ssize_t vbus_show(struct device *device,
<------><------><------>       struct device_attribute *attr, char *buf)
{
<------>struct tahvo_usb *tu = dev_get_drvdata(device);
<------>return sprintf(buf, "%s\n", tu->vbus_state ? "on" : "off");
}
static DEVICE_ATTR_RO(vbus);
 
static void check_vbus_state(struct tahvo_usb *tu)
{
<------>struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
<------>int reg, prev_state;
 
<------>reg = retu_read(rdev, TAHVO_REG_IDSR);
<------>if (reg & TAHVO_STAT_VBUS) {
<------><------>switch (tu->phy.otg->state) {
<------><------>case OTG_STATE_B_IDLE:
<------><------><------>/* Enable the gadget driver */
<------><------><------>if (tu->phy.otg->gadget)
<------><------><------><------>usb_gadget_vbus_connect(tu->phy.otg->gadget);
<------><------><------>tu->phy.otg->state = OTG_STATE_B_PERIPHERAL;
<------><------><------>usb_phy_set_event(&tu->phy, USB_EVENT_ENUMERATED);
<------><------><------>break;
<------><------>case OTG_STATE_A_IDLE:
<------><------><------>/*
<------><------><------> * Session is now valid assuming the USB hub is driving
<------><------><------> * Vbus.
<------><------><------> */
<------><------><------>tu->phy.otg->state = OTG_STATE_A_HOST;
<------><------><------>break;
<------><------>default:
<------><------><------>break;
<------><------>}
<------><------>dev_info(&tu->pt_dev->dev, "USB cable connected\n");
<------>} else {
<------><------>switch (tu->phy.otg->state) {
<------><------>case OTG_STATE_B_PERIPHERAL:
<------><------><------>if (tu->phy.otg->gadget)
<------><------><------><------>usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
<------><------><------>tu->phy.otg->state = OTG_STATE_B_IDLE;
<------><------><------>usb_phy_set_event(&tu->phy, USB_EVENT_NONE);
<------><------><------>break;
<------><------>case OTG_STATE_A_HOST:
<------><------><------>tu->phy.otg->state = OTG_STATE_A_IDLE;
<------><------><------>break;
<------><------>default:
<------><------><------>break;
<------><------>}
<------><------>dev_info(&tu->pt_dev->dev, "USB cable disconnected\n");
<------>}
 
<------>prev_state = tu->vbus_state;
<------>tu->vbus_state = reg & TAHVO_STAT_VBUS;
<------>if (prev_state != tu->vbus_state) {
<------><------>extcon_set_state_sync(tu->extcon, EXTCON_USB, tu->vbus_state);
<------><------>sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state");
<------>}
}
 
static void tahvo_usb_become_host(struct tahvo_usb *tu)
{
<------>struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 
<------>extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST, true);
 
<------>/* Power up the transceiver in USB host mode */
<------>retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
<------><------>   USBR_MASTER_SW2 | USBR_MASTER_SW1);
<------>tu->phy.otg->state = OTG_STATE_A_IDLE;
 
<------>check_vbus_state(tu);
}
 
static void tahvo_usb_stop_host(struct tahvo_usb *tu)
{
<------>tu->phy.otg->state = OTG_STATE_A_IDLE;
}
 
static void tahvo_usb_become_peripheral(struct tahvo_usb *tu)
{
<------>struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 
<------>extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST, false);
 
<------>/* Power up transceiver and set it in USB peripheral mode */
<------>retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT |
<------><------>   USBR_NSUSPEND | USBR_SLAVE_SW);
<------>tu->phy.otg->state = OTG_STATE_B_IDLE;
 
<------>check_vbus_state(tu);
}
 
static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu)
{
<------>if (tu->phy.otg->gadget)
<------><------>usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
<------>tu->phy.otg->state = OTG_STATE_B_IDLE;
}
 
static void tahvo_usb_power_off(struct tahvo_usb *tu)
{
<------>struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
 
<------>/* Disable gadget controller if any */
<------>if (tu->phy.otg->gadget)
<------><------>usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 
<------>/* Power off transceiver */
<------>retu_write(rdev, TAHVO_REG_USBR, 0);
<------>tu->phy.otg->state = OTG_STATE_UNDEFINED;
}
 
static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend)
{
<------>struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy);
<------>struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
<------>u16 w;
 
<------>dev_dbg(&tu->pt_dev->dev, "%s\n", __func__);
 
<------>w = retu_read(rdev, TAHVO_REG_USBR);
<------>if (suspend)
<------><------>w &= ~USBR_NSUSPEND;
<------>else
<------><------>w |= USBR_NSUSPEND;
<------>retu_write(rdev, TAHVO_REG_USBR, w);
 
<------>return 0;
}
 
static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
{
<------>struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb,
<------><------><------><------><------>    phy);
 
<------>dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
 
<------>mutex_lock(&tu->serialize);
 
<------>if (host == NULL) {
<------><------>if (tu->tahvo_mode == TAHVO_MODE_HOST)
<------><------><------>tahvo_usb_power_off(tu);
<------><------>otg->host = NULL;
<------><------>mutex_unlock(&tu->serialize);
<------><------>return 0;
<------>}
 
<------>if (tu->tahvo_mode == TAHVO_MODE_HOST) {
<------><------>otg->host = NULL;
<------><------>tahvo_usb_become_host(tu);
<------>}
 
<------>otg->host = host;
 
<------>mutex_unlock(&tu->serialize);
 
<------>return 0;
}
 
static int tahvo_usb_set_peripheral(struct usb_otg *otg,
<------><------><------><------>    struct usb_gadget *gadget)
{
<------>struct tahvo_usb *tu = container_of(otg->usb_phy, struct tahvo_usb,
<------><------><------><------><------>    phy);
 
<------>dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget);
 
<------>mutex_lock(&tu->serialize);
 
<------>if (!gadget) {
<------><------>if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
<------><------><------>tahvo_usb_power_off(tu);
<------><------>tu->phy.otg->gadget = NULL;
<------><------>mutex_unlock(&tu->serialize);
<------><------>return 0;
<------>}
 
<------>tu->phy.otg->gadget = gadget;
<------>if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
<------><------>tahvo_usb_become_peripheral(tu);
 
<------>mutex_unlock(&tu->serialize);
 
<------>return 0;
}
 
static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu)
{
<------>struct tahvo_usb *tu = _tu;
 
<------>mutex_lock(&tu->serialize);
<------>check_vbus_state(tu);
<------>mutex_unlock(&tu->serialize);
 
<------>return IRQ_HANDLED;
}
 
static ssize_t otg_mode_show(struct device *device,
<------><------><------>     struct device_attribute *attr, char *buf)
{
<------>struct tahvo_usb *tu = dev_get_drvdata(device);
 
<------>switch (tu->tahvo_mode) {
<------>case TAHVO_MODE_HOST:
<------><------>return sprintf(buf, "host\n");
<------>case TAHVO_MODE_PERIPHERAL:
<------><------>return sprintf(buf, "peripheral\n");
<------>}
 
<------>return -EINVAL;
}
 
static ssize_t otg_mode_store(struct device *device,
<------><------><------>      struct device_attribute *attr,
<------><------><------>      const char *buf, size_t count)
{
<------>struct tahvo_usb *tu = dev_get_drvdata(device);
<------>int r;
 
<------>mutex_lock(&tu->serialize);
<------>if (count >= 4 && strncmp(buf, "host", 4) == 0) {
<------><------>if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
<------><------><------>tahvo_usb_stop_peripheral(tu);
<------><------>tu->tahvo_mode = TAHVO_MODE_HOST;
<------><------>if (tu->phy.otg->host) {
<------><------><------>dev_info(device, "HOST mode: host controller present\n");
<------><------><------>tahvo_usb_become_host(tu);
<------><------>} else {
<------><------><------>dev_info(device, "HOST mode: no host controller, powering off\n");
<------><------><------>tahvo_usb_power_off(tu);
<------><------>}
<------><------>r = strlen(buf);
<------>} else if (count >= 10 && strncmp(buf, "peripheral", 10) == 0) {
<------><------>if (tu->tahvo_mode == TAHVO_MODE_HOST)
<------><------><------>tahvo_usb_stop_host(tu);
<------><------>tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
<------><------>if (tu->phy.otg->gadget) {
<------><------><------>dev_info(device, "PERIPHERAL mode: gadget driver present\n");
<------><------><------>tahvo_usb_become_peripheral(tu);
<------><------>} else {
<------><------><------>dev_info(device, "PERIPHERAL mode: no gadget driver, powering off\n");
<------><------><------>tahvo_usb_power_off(tu);
<------><------>}
<------><------>r = strlen(buf);
<------>} else {
<------><------>r = -EINVAL;
<------>}
<------>mutex_unlock(&tu->serialize);
 
<------>return r;
}
static DEVICE_ATTR_RW(otg_mode);
 
static struct attribute *tahvo_attrs[] = {
<------>&dev_attr_vbus.attr,
<------>&dev_attr_otg_mode.attr,
<------>NULL
};
ATTRIBUTE_GROUPS(tahvo);
 
static int tahvo_usb_probe(struct platform_device *pdev)
{
<------>struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
<------>struct tahvo_usb *tu;
<------>int ret;
 
<------>tu = devm_kzalloc(&pdev->dev, sizeof(*tu), GFP_KERNEL);
<------>if (!tu)
<------><------>return -ENOMEM;
 
<------>tu->phy.otg = devm_kzalloc(&pdev->dev, sizeof(*tu->phy.otg),
<------><------><------><------>   GFP_KERNEL);
<------>if (!tu->phy.otg)
<------><------>return -ENOMEM;
 
<------>tu->pt_dev = pdev;
 
<------>/* Default mode */
#ifdef CONFIG_TAHVO_USB_HOST_BY_DEFAULT
<------>tu->tahvo_mode = TAHVO_MODE_HOST;
#else
<------>tu->tahvo_mode = TAHVO_MODE_PERIPHERAL;
#endif
 
<------>mutex_init(&tu->serialize);
 
<------>tu->ick = devm_clk_get(&pdev->dev, "usb_l4_ick");
<------>if (!IS_ERR(tu->ick))
<------><------>clk_enable(tu->ick);
 
<------>/*
<------> * Set initial state, so that we generate kevents only on state changes.
<------> */
<------>tu->vbus_state = retu_read(rdev, TAHVO_REG_IDSR) & TAHVO_STAT_VBUS;
 
<------>tu->extcon = devm_extcon_dev_allocate(&pdev->dev, tahvo_cable);
<------>if (IS_ERR(tu->extcon)) {
<------><------>dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
<------><------>ret = PTR_ERR(tu->extcon);
<------><------>goto err_disable_clk;
<------>}
 
<------>ret = devm_extcon_dev_register(&pdev->dev, tu->extcon);
<------>if (ret) {
<------><------>dev_err(&pdev->dev, "could not register extcon device: %d\n",
<------><------><------>ret);
<------><------>goto err_disable_clk;
<------>}
 
<------>/* Set the initial cable state. */
<------>extcon_set_state_sync(tu->extcon, EXTCON_USB_HOST,
<------><------><------>       tu->tahvo_mode == TAHVO_MODE_HOST);
<------>extcon_set_state_sync(tu->extcon, EXTCON_USB, tu->vbus_state);
 
<------>/* Create OTG interface */
<------>tahvo_usb_power_off(tu);
<------>tu->phy.dev = &pdev->dev;
<------>tu->phy.otg->state = OTG_STATE_UNDEFINED;
<------>tu->phy.label = DRIVER_NAME;
<------>tu->phy.set_suspend = tahvo_usb_set_suspend;
 
<------>tu->phy.otg->usb_phy = &tu->phy;
<------>tu->phy.otg->set_host = tahvo_usb_set_host;
<------>tu->phy.otg->set_peripheral = tahvo_usb_set_peripheral;
 
<------>ret = usb_add_phy(&tu->phy, USB_PHY_TYPE_USB2);
<------>if (ret < 0) {
<------><------>dev_err(&pdev->dev, "cannot register USB transceiver: %d\n",
<------><------><------>ret);
<------><------>goto err_disable_clk;
<------>}
 
<------>dev_set_drvdata(&pdev->dev, tu);
 
<------>tu->irq = ret = platform_get_irq(pdev, 0);
<------>if (ret < 0)
<------><------>return ret;
<------>ret = request_threaded_irq(tu->irq, NULL, tahvo_usb_vbus_interrupt,
<------><------><------><------>   IRQF_ONESHOT,
<------><------><------><------>   "tahvo-vbus", tu);
<------>if (ret) {
<------><------>dev_err(&pdev->dev, "could not register tahvo-vbus irq: %d\n",
<------><------><------>ret);
<------><------>goto err_remove_phy;
<------>}
 
<------>return 0;
 
err_remove_phy:
<------>usb_remove_phy(&tu->phy);
err_disable_clk:
<------>if (!IS_ERR(tu->ick))
<------><------>clk_disable(tu->ick);
 
<------>return ret;
}
 
static int tahvo_usb_remove(struct platform_device *pdev)
{
<------>struct tahvo_usb *tu = platform_get_drvdata(pdev);
 
<------>free_irq(tu->irq, tu);
<------>usb_remove_phy(&tu->phy);
<------>if (!IS_ERR(tu->ick))
<------><------>clk_disable(tu->ick);
 
<------>return 0;
}
 
static struct platform_driver tahvo_usb_driver = {
<------>.probe		= tahvo_usb_probe,
<------>.remove		= tahvo_usb_remove,
<------>.driver		= {
<------><------>.name	= "tahvo-usb",
<------><------>.dev_groups = tahvo_groups,
<------>},
};
module_platform_driver(tahvo_usb_driver);
 
MODULE_DESCRIPTION("Tahvo USB transceiver driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Juha Yrjölä, Tony Lindgren, and Timo Teräs");
MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");