[PATCH 7/7] mfd: intel_vuport: Add Intel virtual USB port MFD Driver

[Lu Baolu <baolu.lu@linux.intel.com>]

Some Intel platforms have an USB port mux controlled by GPIOs.
There's a single ACPI platform device that provides both USB ID
extcon device and a USB port mux device. This MFD driver will
split the 2 devices for their respective drivers.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Suggested-by: David Cohen <david.a.cohen@linux.intel.com>
Reviewed-by: Felipe Balbi <balbi@kernel.org>
---
 MAINTAINERS                |  1 +
 drivers/mfd/Kconfig        |  7 ++++
 drivers/mfd/Makefile       |  1 +
 drivers/mfd/intel-vuport.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 88 insertions(+)
 create mode 100644 drivers/mfd/intel-vuport.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 20eb873..6e0bb12 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11397,6 +11397,7 @@ F:	drivers/usb/misc/mux.c
 F:	include/linux/usb/mux.h
 F:	drivers/usb/misc/intel-mux-gpio.c
 F:	drivers/usb/misc/intel-mux-drcfg.c
+F:	drivers/mfd/intel-vuport.c
 
 USB PRINTER DRIVER (usblp)
 M:	Pete Zaitcev <zaitcev@redhat.com>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 9ca66de..0913494 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1534,5 +1534,12 @@ config MFD_VEXPRESS_SYSREG
 	  System Registers are the platform configuration block
 	  on the ARM Ltd. Versatile Express board.
 
+config MFD_INTEL_VUPORT
+	tristate "Intel virtual USB port controller"
+	select MFD_CORE
+	help
+	  Say Y here to enable support for Intel dual role port mux
+	  controlled by 3 GPIOs.
+
 endmenu
 endif
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 0f230a6..0ccd107 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -198,3 +198,4 @@ intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
 intel-soc-pmic-$(CONFIG_INTEL_PMC_IPC)	+= intel_soc_pmic_bxtwc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
 obj-$(CONFIG_MFD_MT6397)	+= mt6397-core.o
+obj-$(CONFIG_MFD_INTEL_VUPORT)	+= intel-vuport.o
diff --git a/drivers/mfd/intel-vuport.c b/drivers/mfd/intel-vuport.c
new file mode 100644
index 0000000..63391dc
--- /dev/null
+++ b/drivers/mfd/intel-vuport.c
@@ -0,0 +1,79 @@
+/*
+ * MFD driver for Intel virtual USB port
+ *
+ * Copyright(c) 2016 Intel Corporation.
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/gpio.h>
+#include <linux/mfd/core.h>
+#include <linux/platform_device.h>
+
+/* ACPI GPIO Mappings */
+static const struct acpi_gpio_params id_gpio = { 0, 0, false };
+static const struct acpi_gpio_params vbus_gpio = { 1, 0, false };
+static const struct acpi_gpio_params mux_gpio = { 2, 0, false };
+static const struct acpi_gpio_mapping acpi_usb_gpios[] = {
+	{ "id-gpios", &id_gpio, 1 },
+	{ "vbus_en-gpios", &vbus_gpio, 1 },
+	{ "usb_mux-gpios", &mux_gpio, 1 },
+	{ },
+};
+
+static const struct mfd_cell intel_vuport_mfd_cells[] = {
+	{
+		.name = "extcon-usb-gpio",
+	},
+	{
+		.name = "intel-mux-gpio",
+	},
+};
+
+static int vuport_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	ret = acpi_dev_add_driver_gpios(ACPI_COMPANION(dev), acpi_usb_gpios);
+	if (ret)
+		return ret;
+
+	return mfd_add_devices(&pdev->dev, 0, intel_vuport_mfd_cells,
+			ARRAY_SIZE(intel_vuport_mfd_cells), NULL, 0,
+			NULL);
+}
+
+static int vuport_remove(struct platform_device *pdev)
+{
+	mfd_remove_devices(&pdev->dev);
+	acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->dev));
+
+	return 0;
+}
+
+static struct acpi_device_id vuport_acpi_match[] = {
+	{ "INT3496" },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, vuport_acpi_match);
+
+static struct platform_driver vuport_driver = {
+	.driver = {
+		.name = "intel-vuport",
+		.owner = THIS_MODULE,
+		.acpi_match_table = ACPI_PTR(vuport_acpi_match),
+	},
+	.probe = vuport_probe,
+	.remove = vuport_remove,
+};
+
+module_platform_driver(vuport_driver);
+
+MODULE_AUTHOR("Lu Baolu <baolu.lu@linux.intel.com>");
+MODULE_DESCRIPTION("Intel virtual USB port");
+MODULE_LICENSE("GPL v2");
-- 
2.1.4