[PATCH v2 2/2] usb: typec: add typec switch via GPIO control

[Jun Li <jun.li@nxp.com>]

This patch adds a simple typec switch driver which only needs
a GPIO to switch the super speed active channel according to
typec orientation.

Signed-off-by: Li Jun <jun.li@nxp.com>
---

Changes for v2:
- Use the correct head files for gpio api and of_device_id:
  #include <linux/gpio/consumer.h>
  #include <linux/mod_devicetable.h>
- Add driver dependency on GPIOLIB

 drivers/usb/typec/mux/Kconfig       |   7 +++
 drivers/usb/typec/mux/Makefile      |   1 +
 drivers/usb/typec/mux/gpio-switch.c | 105 ++++++++++++++++++++++++++++++++++++
 3 files changed, 113 insertions(+)

diff --git a/drivers/usb/typec/mux/Kconfig b/drivers/usb/typec/mux/Kconfig
index 01ed0d5..27120e6 100644
--- a/drivers/usb/typec/mux/Kconfig
+++ b/drivers/usb/typec/mux/Kconfig
@@ -9,4 +9,11 @@ config TYPEC_MUX_PI3USB30532
 	  Say Y or M if your system has a Pericom PI3USB30532 Type-C cross
 	  switch / mux chip found on some devices with a Type-C port.
 
+config TYPEC_SWITCH_GPIO
+	tristate "Simple Super Speed Active Switch via GPIO"
+	depends on GPIOLIB
+	help
+	  Say Y or M if your system has a typec super speed channel
+	  switch via a simple GPIO control.
+
 endmenu
diff --git a/drivers/usb/typec/mux/Makefile b/drivers/usb/typec/mux/Makefile
index 1332e46..e29377c 100644
--- a/drivers/usb/typec/mux/Makefile
+++ b/drivers/usb/typec/mux/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_TYPEC_MUX_PI3USB30532)	+= pi3usb30532.o
+obj-$(CONFIG_TYPEC_SWITCH_GPIO)		+= gpio-switch.o
diff --git a/drivers/usb/typec/mux/gpio-switch.c b/drivers/usb/typec/mux/gpio-switch.c
new file mode 100644
index 0000000..b01844c
--- /dev/null
+++ b/drivers/usb/typec/mux/gpio-switch.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * gpio-switch.c - typec switch via a simple GPIO control.
+ *
+ * Copyright 2019 NXP
+ * Author: Jun Li <jun.li@nxp.com>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mod_devicetable.h>
+#include <linux/usb/typec_mux.h>
+
+struct gpio_typec_switch {
+	struct typec_switch sw;
+	struct mutex lock;
+	struct gpio_desc *ss_sel;
+};
+
+static int switch_gpio_set(struct typec_switch *sw,
+			   enum typec_orientation orientation)
+{
+	struct gpio_typec_switch *gpio_sw = container_of(sw,
+				struct gpio_typec_switch, sw);
+
+	mutex_lock(&gpio_sw->lock);
+
+	switch (orientation) {
+	case TYPEC_ORIENTATION_NORMAL:
+		gpiod_set_value_cansleep(gpio_sw->ss_sel, 1);
+		break;
+	case TYPEC_ORIENTATION_REVERSE:
+		gpiod_set_value_cansleep(gpio_sw->ss_sel, 0);
+		break;
+	case TYPEC_ORIENTATION_NONE:
+		break;
+	}
+
+	mutex_unlock(&gpio_sw->lock);
+
+	return 0;
+}
+
+static int typec_switch_gpio_probe(struct platform_device *pdev)
+{
+	struct gpio_typec_switch	*gpio_sw;
+	struct device			*dev = &pdev->dev;
+	int				ret;
+
+	gpio_sw = devm_kzalloc(dev, sizeof(*gpio_sw), GFP_KERNEL);
+	if (!gpio_sw)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, gpio_sw);
+
+	gpio_sw->sw.dev = dev;
+	gpio_sw->sw.set = switch_gpio_set;
+	mutex_init(&gpio_sw->lock);
+
+	/* Get the super speed active channel selection GPIO */
+	gpio_sw->ss_sel = devm_gpiod_get(dev, NULL, GPIOD_OUT_LOW);
+	if (IS_ERR(gpio_sw->ss_sel))
+		return PTR_ERR(gpio_sw->ss_sel);
+
+	ret = typec_switch_register(&gpio_sw->sw);
+	if (ret) {
+		dev_err(dev, "Error registering typec switch: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int typec_switch_gpio_remove(struct platform_device *pdev)
+{
+	struct gpio_typec_switch *gpio_sw = platform_get_drvdata(pdev);
+
+	typec_switch_unregister(&gpio_sw->sw);
+
+	return 0;
+}
+
+static const struct of_device_id of_typec_switch_gpio_match[] = {
+	{ .compatible = "nxp,ptn36043" },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, of_typec_switch_gpio_match);
+
+static struct platform_driver typec_switch_gpio_driver = {
+	.probe		= typec_switch_gpio_probe,
+	.remove		= typec_switch_gpio_remove,
+	.driver		= {
+		.name	= "typec-switch-gpio",
+		.of_match_table = of_typec_switch_gpio_match,
+	},
+};
+
+module_platform_driver(typec_switch_gpio_driver);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("TypeC Super Speed Switch GPIO driver");
+MODULE_AUTHOR("Jun Li <jun.li@nxp.com>");
-- 
2.7.4