From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthe...@linux.intel.com>

Add support for USB PHY on Intel LGM SoC.

Signed-off-by: Ramuthevar Vadivel Murugan 
<vadivel.muruganx.ramuthe...@linux.intel.com>
Reviewed-by: Philipp Zabel <p.za...@pengutronix.de>
---
 drivers/phy/Kconfig       |  11 ++
 drivers/phy/Makefile      |   3 +-
 drivers/phy/phy-lgm-usb.c | 278 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 291 insertions(+), 1 deletion(-)
 create mode 100644 drivers/phy/phy-lgm-usb.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index de9362c25c07..01b53f86004c 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -49,6 +49,17 @@ config PHY_XGENE
        help
          This option enables support for APM X-Gene SoC multi-purpose PHY.
 
+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.
+
 source "drivers/phy/allwinner/Kconfig"
 source "drivers/phy/amlogic/Kconfig"
 source "drivers/phy/broadcom/Kconfig"
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index c27408e4daae..90030ff299eb 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0
+PDX-License-Identifier: GPL-2.0
 #
 # Makefile for the phy drivers.
 #
@@ -8,6 +8,7 @@ obj-$(CONFIG_GENERIC_PHY_MIPI_DPHY)     += phy-core-mipi-dphy.o
 obj-$(CONFIG_PHY_LPC18XX_USB_OTG)      += phy-lpc18xx-usb-otg.o
 obj-$(CONFIG_PHY_XGENE)                        += phy-xgene.o
 obj-$(CONFIG_PHY_PISTACHIO_USB)                += phy-pistachio-usb.o
+obj-$(CONFIG_USB_LGM_PHY)              += phy-lgm-usb.o
 obj-y                                  += allwinner/   \
                                           amlogic/     \
                                           broadcom/    \
diff --git a/drivers/phy/phy-lgm-usb.c b/drivers/phy/phy-lgm-usb.c
new file mode 100644
index 000000000000..1ec9ab266e08
--- /dev/null
+++ b/drivers/phy/phy-lgm-usb.c
@@ -0,0 +1,278 @@
+// 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 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) {
+               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) {
+               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_CONN;
+               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...@intel.com>");
+MODULE_AUTHOR("Vadivel Murugan R 
<vadivel.muruganx.ramuthe...@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.11.0

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