[PATCH v2 1/3] platform/x86: Add Intel Input Output Manager (IOM) driver

From: Rajmohan Mani
Date: Sat Aug 22 2020 - 00:42:18 EST

Input Output Manager (IOM) is part of the Tiger Lake SoC that
configures the Type-C Sub System (TCSS). IOM is a micro controller
that handles Type-C topology, configuration and PM functions of
various Type-C devices connected on the platform.

This driver helps read relevant information such as Type-C port
status (whether a device is connected to a Type-C port or not) and
the activity type on the Type-C ports (such as USB, Display Port,
Thunderbolt), for consumption by other drivers.

Currently intel_iom_port_status() API is exported by this driver,
that has information about the Type-C port status and port activity
type.

Signed-off-by: Rajmohan Mani <rajmohan.mani@xxxxxxxxx>
---
drivers/platform/x86/Kconfig | 16 ++++
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/intel_iom.c | 95 +++++++++++++++++++++
include/linux/platform_data/x86/intel_iom.h | 49 +++++++++++
4 files changed, 161 insertions(+)
create mode 100644 drivers/platform/x86/intel_iom.c
create mode 100644 include/linux/platform_data/x86/intel_iom.h

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 40219bba6801..f09b4b525ea5 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -837,6 +837,22 @@ config INTEL_INT0002_VGPIO
To compile this driver as a module, choose M here: the module will
be called intel_int0002_vgpio.

+config INTEL_IOM
+ tristate "Intel Input Output Manager (IOM) driver"
+ depends on ACPI && PCI
+ help
+ This driver helps read relevant information such as Type-C port
+ status (whether a device is connected to a Type-C port or not)
+ and the activity type on the Type-C ports (such as USB, Display
+ Port, Thunderbolt), for consumption by other drivers.
+
+ Currently intel_iom_port_status() API is exported by this driver,
+ that has information about the Type-C port status and port activity
+ type.
+
+ To compile this driver as a module, choose M here: the module will
+ be called intel_iom.
+
config INTEL_MENLOW
tristate "Thermal Management driver for Intel menlow platform"
depends on ACPI_THERMAL
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 5f823f7eff45..b44f706074c3 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -77,6 +77,7 @@ intel_cht_int33fe-objs := intel_cht_int33fe_common.o \
intel_cht_int33fe_microb.o
obj-$(CONFIG_INTEL_HID_EVENT) += intel-hid.o
obj-$(CONFIG_INTEL_INT0002_VGPIO) += intel_int0002_vgpio.o
+obj-$(CONFIG_INTEL_IOM) += intel_iom.o
obj-$(CONFIG_INTEL_MENLOW) += intel_menlow.o
obj-$(CONFIG_INTEL_OAKTRAIL) += intel_oaktrail.o
obj-$(CONFIG_INTEL_VBTN) += intel-vbtn.o
diff --git a/drivers/platform/x86/intel_iom.c b/drivers/platform/x86/intel_iom.c
new file mode 100644
index 000000000000..cda7716410c6
--- /dev/null
+++ b/drivers/platform/x86/intel_iom.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel Core SoC Input Output Manager (IOM) driver.
+ *
+ * This driver provides access to the Input Output Manager (IOM) (that
+ * is part of Tiger Lake SoC) registers that can be used to know about
+ * Type-C Sub System related information (such as Type-C port status,
+ * activity type on Type-C ports).
+ *
+ * Copyright (C) 2020, Intel Corporation
+ * Author: Rajmohan Mani <rajmohan.mani@xxxxxxxxx>
+ */
+
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_data/x86/intel_iom.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define IOM_PORT_STATUS_OFFSET 0x560
+
+struct intel_iom {
+ struct device *dev;
+ void __iomem *regbar;
+};
+
+static struct intel_iom *iom;
+
+/**
+ * intel_iom_port_status() - Get status bits for the Type-C port
+ * @port: Type-C port number
+ * @status: pointer to receive the status bits
+ *
+ * Returns 0 on success, error otherwise.
+ */
+int intel_iom_port_status(u8 port, u32 *status)
+{
+ void __iomem *reg;
+
+ if (!iom || !iom->dev || !iom->regbar)
+ return -ENODEV;
+
+ if (!status || (port > IOM_MAX_PORTS - 1))
+ return -EINVAL;
+
+ reg = iom->regbar + IOM_PORT_STATUS_OFFSET + IOM_REG_LEN * port;
+
+ *status = ioread32(reg);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(intel_iom_port_status);
+
+static int intel_iom_probe(struct platform_device *pdev)
+{
+ void __iomem *addr;
+
+ /* only one IOM device is supported */
+ if (iom)
+ return -EBUSY;
+
+ iom = devm_kzalloc(&pdev->dev, sizeof(*iom), GFP_KERNEL);
+ if (!iom)
+ return -ENOMEM;
+
+ addr = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(addr))
+ return PTR_ERR(addr);
+
+ iom->regbar = addr;
+ iom->dev = &pdev->dev;
+
+ return 0;
+}
+
+static const struct acpi_device_id intel_iom_acpi_ids[] = {
+ { "INTC1072" },
+ {}
+};
+MODULE_DEVICE_TABLE(acpi, intel_iom_acpi_ids);
+
+static struct platform_driver intel_iom_driver = {
+ .probe = intel_iom_probe,
+ .driver = {
+ .name = "intel_iom",
+ .acpi_match_table = intel_iom_acpi_ids,
+ },
+};
+
+module_platform_driver_probe(intel_iom_driver, intel_iom_probe);
+
+MODULE_AUTHOR("Rajmohan Mani <rajmohan.mani@xxxxxxxxx>");
+MODULE_DESCRIPTION("Intel IOM driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/platform_data/x86/intel_iom.h b/include/linux/platform_data/x86/intel_iom.h
new file mode 100644
index 000000000000..e4c9a305e7a9
--- /dev/null
+++ b/include/linux/platform_data/x86/intel_iom.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _PLATFORM_DATA_X86_INTEL_IOM_H_
+#define _PLATFORM_DATA_X86_INTEL_IOM_H_
+
+#include <linux/bits.h>
+#include <linux/types.h>
+
+/* Input Output Manager (IOM) PORT STATUS */
+#define IOM_PORT_STATUS_ACTIVITY_TYPE_MASK GENMASK(9, 6)
+#define IOM_PORT_STATUS_ACTIVITY_TYPE_SHIFT 0x06
+#define IOM_PORT_STATUS_ACTIVITY_TYPE_USB 0x03
+/* activity type: Safe Mode */
+#define IOM_PORT_STATUS_ACTIVITY_TYPE_SAFE_MODE 0x04
+/* activity type: Display Port */
+#define IOM_PORT_STATUS_ACTIVITY_TYPE_DP 0x05
+/* activity type: Display Port Multi Function Device */
+#define IOM_PORT_STATUS_ACTIVITY_TYPE_DP_MFD 0x06
+/* activity type: Thunderbolt */
+#define IOM_PORT_STATUS_ACTIVITY_TYPE_TBT 0x07
+#define IOM_PORT_STATUS_ACTIVITY_TYPE_ALT_MODE_USB 0x0c
+#define IOM_PORT_STATUS_ACTIVITY_TYPE_ALT_MODE_TBT_USB 0x0d
+/* Upstream Facing Port Information */
+#define IOM_PORT_STATUS_UFP BIT(10)
+/* Display Port Hot Plug Detect status */
+#define IOM_PORT_STATUS_DHPD_HPD_STATUS_MASK GENMASK(13, 12)
+#define IOM_PORT_STATUS_DHPD_HPD_STATUS_SHIFT 0x0c
+#define IOM_PORT_STATUS_DHPD_HPD_STATUS_ASSERT 0x01
+#define IOM_PORT_STATUS_DHPD_HPD_SOURCE_TBT BIT(14)
+#define IOM_PORT_STATUS_CONNECTED BIT(31)
+
+#define IOM_MAX_PORTS 4
+/* Register length in bytes */
+#define IOM_REG_LEN 4
+
+#ifdef CONFIG_ACPI
+
+int intel_iom_port_status(u8 port, u32 *status);
+
+#else
+
+int intel_iom_port_status(struct intel_iom *iom, u8 port, u32 *status)
+{
+ return 0;
+}
+
+#endif
+
+#endif /* _PLATFORM_DATA_X86_INTEL_IOM_H_ */
--
2.20.1