[PATCH v4 2/2] usb: phy: Add USB3 PHY support for Intel LGM SoC

From: Ramuthevar,Vadivel MuruganX
Date: Wed Jun 17 2020 - 00:00:27 EST


From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>

Add support for USB PHY on Intel LGM SoC.

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
---
drivers/usb/phy/Kconfig | 11 ++
drivers/usb/phy/Makefile | 1 +
drivers/usb/phy/phy-lgm-usb.c | 275 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 287 insertions(+)
create mode 100644 drivers/usb/phy/phy-lgm-usb.c

diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 4b3fa78995cf..95f2e737d663 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -192,4 +192,15 @@ config JZ4770_PHY
This driver provides PHY support for the USB controller found
on the JZ4770 SoC from Ingenic.

+config USB_LGM_PHY
+ tristate "INTEL Lightning Mountain USB PHY Driver"
+ depends on USB_SUPPORT
+ select USB_PHY
+ select REGULATOR
+ select REGULATOR_FIXED_VOLTAGE
+ help
+ Enable this to support Intel DWC3 PHY USB phy. This driver provides
+ interface to interact with USB GEN-II and USB 3.x PHY that is part
+ of the Intel network SOC.
+
endmenu
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index b352bdbe8712..ef5345164e10 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -25,3 +25,4 @@ obj-$(CONFIG_USB_ULPI) += phy-ulpi.o
obj-$(CONFIG_USB_ULPI_VIEWPORT) += phy-ulpi-viewport.o
obj-$(CONFIG_KEYSTONE_USB_PHY) += phy-keystone.o
obj-$(CONFIG_JZ4770_PHY) += phy-jz4770.o
+obj-$(CONFIG_USB_LGM_PHY) += phy-lgm-usb.o
diff --git a/drivers/usb/phy/phy-lgm-usb.c b/drivers/usb/phy/phy-lgm-usb.c
new file mode 100644
index 000000000000..3da772dfd736
--- /dev/null
+++ b/drivers/usb/phy/phy-lgm-usb.c
@@ -0,0 +1,275 @@
+// 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_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 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 ret;
+}
+
+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)
+ 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);
+ if (ta->connected) {
+ 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) {
+ ret = regulator_enable(ta->vbus);
+ if (ret)
+ dev_err(ta->phy.dev, "regulator not enabled\n");
+ } else {
+ ret = regulator_disable(ta->vbus);
+ if (ret)
+ dev_err(ta->phy.dev, "regulator not disabled\n");
+ }
+
+ 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);
+ connected = extcon_get_state(ta->phy.edev, EXTCON_USB_HOST) && !ret;
+ if (connected == ta->connected)
+ return;
+
+ ta->connected = connected;
+ if (connected) {
+ val = TCPC_VALID | FIELD_PREP(TCPC_MUX_CTL, MUX_USB);
+ if (flipped)
+ val |= TCPC_FLIPPED;
+ dev_info(ta->phy.dev, "connected%s\n", flipped ? " flipped" : "");
+ } else {
+ val = TCPC_DISCONN;
+ dev_info(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 int phy_remove(struct platform_device *pdev)
+{
+ struct tca_apb *ta = platform_get_drvdata(pdev);
+
+ usb_remove_phy(&ta->phy);
+
+ return 0;
+}
+
+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 = phy_remove,
+};
+
+module_platform_driver(lgm_phy_driver);
+
+MODULE_DESCRIPTION("Intel LGM USB PHY driver");
+MODULE_AUTHOR("Li Yin <yin1.li@xxxxxxxxx>");
+MODULE_AUTHOR("Vadivel Murugan R <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
--
2.11.0