// SPDX-License-Identifier: GPL-2.0
/*
* Intel LGM USB PHY driver
*
* Copyright (C) 2020 Intel Corporation.
*/
#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include <linux/usb/phy.h>
#include <linux/workqueue.h>
#define CTRL1_OFFSET 0x14
#define SRAM_EXT_LD_DONE BIT(25)
#define SRAM_INIT_DONE BIT(26)
#define TCPC_OFFSET 0x1014
#define TCPC_MUX_CTL GENMASK(1, 0)
#define MUX_NC 0
#define MUX_USB 1
#define MUX_DP 2
#define MUX_USBDP 3
#define TCPC_FLIPPED BIT(2)
#define TCPC_LOW_POWER_EN BIT(3)
#define TCPC_VALID BIT(4)
#define TCPC_CONN \
(TCPC_VALID | FIELD_PREP(TCPC_MUX_CTL, MUX_USB))
#define TCPC_DISCONN \
(TCPC_VALID | FIELD_PREP(TCPC_MUX_CTL, MUX_NC) | TCPC_LOW_POWER_EN)
static const char *const PHY_RESETS[] = { "phy31", "phy", };
static const char *const CTL_RESETS[] = { "apb", "ctrl", };
struct tca_apb {
struct reset_control *resets[ARRAY_SIZE(PHY_RESETS)];
struct regulator *vbus;
struct work_struct wk;
struct usb_phy phy;
bool regulator_enabled;
bool phy_initialized;
bool connected;
};
static int get_flipped(struct tca_apb *ta, bool *flipped)
{
union extcon_property_value property;
int ret;
ret = extcon_get_property(ta->phy.edev, EXTCON_USB_HOST,
EXTCON_PROP_USB_TYPEC_POLARITY, &property);
if (ret) {
dev_err(ta->phy.dev, "no polarity property from extcon\n");
return ret;
}
*flipped = property.intval;
return 0;
}
static int phy_init(struct usb_phy *phy)
{
struct tca_apb *ta = container_of(phy, struct tca_apb, phy);
void __iomem *ctrl1 = phy->io_priv + CTRL1_OFFSET;
int val, ret, i;
if (ta->phy_initialized)
return 0;
for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++)
reset_control_deassert(ta->resets[i]);
ret = readl_poll_timeout(ctrl1, val, val & SRAM_INIT_DONE, 10, 10 * 1000);
if (ret) {
dev_err(ta->phy.dev, "SRAM init failed, 0x%x\n", val);
return ret;
}
writel(readl(ctrl1) | SRAM_EXT_LD_DONE, ctrl1);
ta->phy_initialized = true;
if (!ta->phy.edev) {
writel(TCPC_CONN, ta->phy.io_priv + TCPC_OFFSET);
return phy->set_vbus(phy, true);
}
schedule_work(&ta->wk);
return ret;
}
static void phy_shutdown(struct usb_phy *phy)
{
struct tca_apb *ta = container_of(phy, struct tca_apb, phy);
int i;
if (!ta->phy_initialized)
return;
ta->phy_initialized = false;
flush_work(&ta->wk);
ta->phy.set_vbus(&ta->phy, false);
ta->connected = false;
writel(TCPC_DISCONN, ta->phy.io_priv + TCPC_OFFSET);
for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++)
reset_control_assert(ta->resets[i]);
}
static int phy_set_vbus(struct usb_phy *phy, int on)
{
struct tca_apb *ta = container_of(phy, struct tca_apb, phy);
int ret;
if (!!on == ta->regulator_enabled)
return 0;
if (on)
ret = regulator_enable(ta->vbus);
else
ret = regulator_disable(ta->vbus);
if (!ret)
ta->regulator_enabled = on;
dev_dbg(ta->phy.dev, "set vbus: %d\n", on);
return ret;
}
static void tca_work(struct work_struct *work)
{
struct tca_apb *ta = container_of(work, struct tca_apb, wk);
bool connected;
bool flipped = false;
u32 val;
int ret;
ret = get_flipped(ta, &flipped);
if (ret)
return;
connected = extcon_get_state(ta->phy.edev, EXTCON_USB_HOST);
if (connected == ta->connected)
return;
ta->connected = connected;
if (connected) {
val = TCPC_CONN;
if (flipped)
val |= TCPC_FLIPPED;
dev_dbg(ta->phy.dev, "connected%s\n", flipped ? " flipped" : "");
} else {
val = TCPC_DISCONN;
dev_dbg(ta->phy.dev, "disconnected\n");
}
writel(val, ta->phy.io_priv + TCPC_OFFSET);
ret = ta->phy.set_vbus(&ta->phy, connected);
if (ret)
dev_err(ta->phy.dev, "failed to set VBUS\n");
}
static int id_notifier(struct notifier_block *nb, unsigned long event, void *ptr)
{
struct tca_apb *ta = container_of(nb, struct tca_apb, phy.id_nb);
if (ta->phy_initialized)
schedule_work(&ta->wk);
return NOTIFY_DONE;
}
static int vbus_notifier(struct notifier_block *nb, unsigned long evnt, void *ptr)
{
return NOTIFY_DONE;
}
static int phy_probe(struct platform_device *pdev)
{
struct reset_control *resets[ARRAY_SIZE(CTL_RESETS)];
struct device *dev = &pdev->dev;
struct usb_phy *phy;
struct tca_apb *ta;
int i;
ta = devm_kzalloc(dev, sizeof(*ta), GFP_KERNEL);
if (!ta)
return -ENOMEM;
platform_set_drvdata(pdev, ta);
INIT_WORK(&ta->wk, tca_work);
phy = &ta->phy;
phy->dev = dev;
phy->label = dev_name(dev);
phy->type = USB_PHY_TYPE_USB3;
phy->init = phy_init;
phy->shutdown = phy_shutdown;
phy->set_vbus = phy_set_vbus;
phy->id_nb.notifier_call = id_notifier;
phy->vbus_nb.notifier_call = vbus_notifier;
phy->io_priv = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(phy->io_priv))
return PTR_ERR(phy->io_priv);
ta->vbus = devm_regulator_get(dev, "vbus");
if (IS_ERR(ta->vbus))
return PTR_ERR(ta->vbus);
for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++) {
resets[i] = devm_reset_control_get_exclusive(dev, CTL_RESETS[i]);
if (IS_ERR(resets[i])) {
dev_err(dev, "%s reset not found\n", CTL_RESETS[i]);
return PTR_ERR(resets[i]);
}
}
for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++) {
ta->resets[i] = devm_reset_control_get_exclusive(dev, PHY_RESETS[i]);
if (IS_ERR(ta->resets[i])) {
dev_err(dev, "%s reset not found\n", PHY_RESETS[i]);
return PTR_ERR(ta->resets[i]);
}
}
for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++)
reset_control_assert(resets[i]);
for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++)
reset_control_assert(ta->resets[i]);
/*
* Out-of-band reset of the controller after PHY reset will cause
* controller malfunctioning, so we should use in-band controller
* reset only and leave the controller de-asserted here.
*/
for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++)
reset_control_deassert(resets[i]);
/* Need to wait at least 20us after de-assert the controller */
usleep_range(20, 100);
return usb_add_phy_dev(phy);
}
static void phy_remove(struct platform_device *pdev)
{
struct tca_apb *ta = platform_get_drvdata(pdev);
usb_remove_phy(&ta->phy);
}
static const struct of_device_id intel_usb_phy_dt_ids[] = {
{ .compatible = "intel,lgm-usb-phy" },
{ }
};
MODULE_DEVICE_TABLE(of, intel_usb_phy_dt_ids);
static struct platform_driver lgm_phy_driver = {
.driver = {
.name = "lgm-usb-phy",
.of_match_table = intel_usb_phy_dt_ids,
},
.probe = phy_probe,
.remove_new = phy_remove,
};
module_platform_driver(lgm_phy_driver);
MODULE_DESCRIPTION("Intel LGM USB PHY driver");
MODULE_AUTHOR("Li Yin <[email protected]>");
MODULE_AUTHOR("Vadivel Murugan R <[email protected]>");
MODULE_LICENSE("GPL v2");
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