// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
*/
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/usb/role.h>
#define EUD_REG_INT1_EN_MASK 0x0024
#define EUD_REG_INT_STATUS_1 0x0044
#define EUD_REG_CTL_OUT_1 0x0074
#define EUD_REG_VBUS_INT_CLR 0x0080
#define EUD_REG_CSR_EUD_EN 0x1014
#define EUD_REG_SW_ATTACH_DET 0x1018
#define EUD_REG_EUD_EN2 0x0000
#define EUD_ENABLE BIT(0)
#define EUD_INT_PET_EUD BIT(0)
#define EUD_INT_VBUS BIT(2)
#define EUD_INT_SAFE_MODE BIT(4)
#define EUD_INT_ALL (EUD_INT_VBUS | EUD_INT_SAFE_MODE)
struct eud_chip {
struct device *dev;
struct usb_role_switch *role_sw;
void __iomem *base;
void __iomem *mode_mgr;
unsigned int int_status;
int irq;
bool enabled;
bool usb_attached;
};
static int enable_eud(struct eud_chip *priv)
{
writel(EUD_ENABLE, priv->base + EUD_REG_CSR_EUD_EN);
writel(EUD_INT_VBUS | EUD_INT_SAFE_MODE,
priv->base + EUD_REG_INT1_EN_MASK);
writel(1, priv->mode_mgr + EUD_REG_EUD_EN2);
return usb_role_switch_set_role(priv->role_sw, USB_ROLE_DEVICE);
}
static void disable_eud(struct eud_chip *priv)
{
writel(0, priv->base + EUD_REG_CSR_EUD_EN);
writel(0, priv->mode_mgr + EUD_REG_EUD_EN2);
}
static ssize_t enable_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct eud_chip *chip = dev_get_drvdata(dev);
return sysfs_emit(buf, "%d\n", chip->enabled);
}
static ssize_t enable_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct eud_chip *chip = dev_get_drvdata(dev);
bool enable;
int ret;
if (kstrtobool(buf, &enable))
return -EINVAL;
if (enable) {
ret = enable_eud(chip);
if (!ret)
chip->enabled = enable;
else
disable_eud(chip);
} else {
disable_eud(chip);
}
return count;
}
static DEVICE_ATTR_RW(enable);
static struct attribute *eud_attrs[] = {
&dev_attr_enable.attr,
NULL,
};
ATTRIBUTE_GROUPS(eud);
static void usb_attach_detach(struct eud_chip *chip)
{
u32 reg;
/* read ctl_out_1[4] to find USB attach or detach event */
reg = readl(chip->base + EUD_REG_CTL_OUT_1);
chip->usb_attached = reg & EUD_INT_SAFE_MODE;
}
static void pet_eud(struct eud_chip *chip)
{
u32 reg;
int ret;
/* When the EUD_INT_PET_EUD in SW_ATTACH_DET is set, the cable has been
* disconnected and we need to detach the pet to check if EUD is in safe
* mode before attaching again.
*/
reg = readl(chip->base + EUD_REG_SW_ATTACH_DET);
if (reg & EUD_INT_PET_EUD) {
/* Detach & Attach pet for EUD */
writel(0, chip->base + EUD_REG_SW_ATTACH_DET);
/* Delay to make sure detach pet is done before attach pet */
ret = readl_poll_timeout(chip->base + EUD_REG_SW_ATTACH_DET,
reg, (reg == 0), 1, 100);
if (ret) {
dev_err(chip->dev, "Detach pet failed\n");
return;
}
}
/* Attach pet for EUD */
writel(EUD_INT_PET_EUD, chip->base + EUD_REG_SW_ATTACH_DET);
}
static irqreturn_t handle_eud_irq(int irq, void *data)
{
struct eud_chip *chip = data;
u32 reg;
reg = readl(chip->base + EUD_REG_INT_STATUS_1);
switch (reg & EUD_INT_ALL) {
case EUD_INT_VBUS:
usb_attach_detach(chip);
return IRQ_WAKE_THREAD;
case EUD_INT_SAFE_MODE:
pet_eud(chip);
return IRQ_HANDLED;
default:
return IRQ_NONE;
}
}
static irqreturn_t handle_eud_irq_thread(int irq, void *data)
{
struct eud_chip *chip = data;
int ret;
if (chip->usb_attached)
ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_DEVICE);
else
ret = usb_role_switch_set_role(chip->role_sw, USB_ROLE_HOST);
if (ret)
dev_err(chip->dev, "failed to set role switch\n");
/* set and clear vbus_int_clr[0] to clear interrupt */
writel(BIT(0), chip->base + EUD_REG_VBUS_INT_CLR);
writel(0, chip->base + EUD_REG_VBUS_INT_CLR);
return IRQ_HANDLED;
}
static void eud_role_switch_release(void *data)
{
struct eud_chip *chip = data;
usb_role_switch_put(chip->role_sw);
}
static int eud_probe(struct platform_device *pdev)
{
struct eud_chip *chip;
int ret;
chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
chip->dev = &pdev->dev;
chip->role_sw = usb_role_switch_get(&pdev->dev);
if (IS_ERR(chip->role_sw))
return dev_err_probe(chip->dev, PTR_ERR(chip->role_sw),
"failed to get role switch\n");
ret = devm_add_action_or_reset(chip->dev, eud_role_switch_release, chip);
if (ret)
return dev_err_probe(chip->dev, ret,
"failed to add role switch release action\n");
chip->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(chip->base))
return PTR_ERR(chip->base);
chip->mode_mgr = devm_platform_ioremap_resource(pdev, 1);
if (IS_ERR(chip->mode_mgr))
return PTR_ERR(chip->mode_mgr);
chip->irq = platform_get_irq(pdev, 0);
if (chip->irq < 0)
return chip->irq;
ret = devm_request_threaded_irq(&pdev->dev, chip->irq, handle_eud_irq,
handle_eud_irq_thread, IRQF_ONESHOT, NULL, chip);
if (ret)
return dev_err_probe(chip->dev, ret, "failed to allocate irq\n");
enable_irq_wake(chip->irq);
platform_set_drvdata(pdev, chip);
return 0;
}
static void eud_remove(struct platform_device *pdev)
{
struct eud_chip *chip = platform_get_drvdata(pdev);
if (chip->enabled)
disable_eud(chip);
device_init_wakeup(&pdev->dev, false);
disable_irq_wake(chip->irq);
}
static const struct of_device_id eud_dt_match[] = {
{ .compatible = "qcom,eud" },
{ }
};
MODULE_DEVICE_TABLE(of, eud_dt_match);
static struct platform_driver eud_driver = {
.probe = eud_probe,
.remove_new = eud_remove,
.driver = {
.name = "qcom_eud",
.dev_groups = eud_groups,
.of_match_table = eud_dt_match,
},
};
module_platform_driver(eud_driver);
MODULE_DESCRIPTION("QTI EUD driver");
MODULE_LICENSE("GPL v2");
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