[PATCH v5 4/4] usb: typec: mux: add typec switch simple driver

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

This patch adds a simple typec switch driver for cases which only
needs some simple operations but a dedicated driver is required,
current driver only supports GPIO toggle to switch the super speed
active channel according to typec orientation.

Signed-off-by: Li Jun <jun.li@nxp.com>
---
Changes for v5:
- A few changes address Andy's comment, remove gpio check as it's
  optional, add module name for Kconfig, use correct header files,
  and other minor changes.
- Remove the mutex lock as it's not required currently.

Changes for v4:
- Change driver name to be switch simple from switch GPIO, to make it
  generic for possible extention.
- Use compatiable "typec-orientation-switch" instead of bool property
  for switch matching.
- Make acitve channel selection GPIO to be optional.
- Remove Andy's R-b tag since the driver changes a lot.

Change for v3:
- Remove file name in driver description.
- Add Andy Shevchenko's Reviewed-by tag.

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         |  10 ++++
 drivers/usb/typec/mux/Makefile        |   1 +
 drivers/usb/typec/mux/switch-simple.c | 100 ++++++++++++++++++++++++++++++++++
 3 files changed, 111 insertions(+)

diff --git a/drivers/usb/typec/mux/Kconfig b/drivers/usb/typec/mux/Kconfig
index a4dbd11..11320d7 100644
--- a/drivers/usb/typec/mux/Kconfig
+++ b/drivers/usb/typec/mux/Kconfig
@@ -18,4 +18,14 @@ config TYPEC_MUX_INTEL_PMC
 	  control the USB role switch and also the multiplexer/demultiplexer
 	  switches used with USB Type-C Alternate Modes.
 
+config TYPEC_SWITCH_SIMPLE
+	tristate "Type-C orientation switch simple driver"
+	depends on GPIOLIB
+	help
+	  Say Y or M if your system need a simple driver for typec switch
+	  control, like use GPIO to select active channel.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called switch-simple.
+
 endmenu
diff --git a/drivers/usb/typec/mux/Makefile b/drivers/usb/typec/mux/Makefile
index 280a6f5..712d0ad 100644
--- a/drivers/usb/typec/mux/Makefile
+++ b/drivers/usb/typec/mux/Makefile
@@ -2,3 +2,4 @@
 
 obj-$(CONFIG_TYPEC_MUX_PI3USB30532)	+= pi3usb30532.o
 obj-$(CONFIG_TYPEC_MUX_INTEL_PMC)	+= intel_pmc_mux.o
+obj-$(CONFIG_TYPEC_SWITCH_SIMPLE)	+= switch-simple.o
diff --git a/drivers/usb/typec/mux/switch-simple.c b/drivers/usb/typec/mux/switch-simple.c
new file mode 100644
index 0000000..8707703
--- /dev/null
+++ b/drivers/usb/typec/mux/switch-simple.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Type-C switch simple control driver
+ *
+ * Copyright 2020 NXP
+ * Author: Jun Li <jun.li@nxp.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/usb/typec_mux.h>
+
+struct typec_switch_simple {
+	struct typec_switch *sw;
+	struct gpio_desc *sel_gpio;
+};
+
+static int typec_switch_simple_set(struct typec_switch *sw,
+				   enum typec_orientation orientation)
+{
+	struct typec_switch_simple *typec_sw = typec_switch_get_drvdata(sw);
+
+	switch (orientation) {
+	case TYPEC_ORIENTATION_NORMAL:
+		gpiod_set_value_cansleep(typec_sw->sel_gpio, 1);
+		break;
+	case TYPEC_ORIENTATION_REVERSE:
+		gpiod_set_value_cansleep(typec_sw->sel_gpio, 0);
+		break;
+	case TYPEC_ORIENTATION_NONE:
+		break;
+	}
+
+	return 0;
+}
+
+static int typec_switch_simple_probe(struct platform_device *pdev)
+{
+	struct device			*dev = &pdev->dev;
+	struct typec_switch_desc	sw_desc;
+	struct typec_switch_simple	*typec_sw;
+
+	typec_sw = devm_kzalloc(dev, sizeof(*typec_sw), GFP_KERNEL);
+	if (!typec_sw)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, typec_sw);
+
+	sw_desc.drvdata = typec_sw;
+	sw_desc.fwnode = dev->fwnode;
+	sw_desc.set = typec_switch_simple_set;
+
+	/* Get the super speed active channel selection GPIO */
+	typec_sw->sel_gpio = devm_gpiod_get_optional(dev, "switch", GPIOD_OUT_LOW);
+	if (IS_ERR(typec_sw->sel_gpio))
+		return PTR_ERR(typec_sw->sel_gpio);
+
+	typec_sw->sw = typec_switch_register(dev, &sw_desc);
+	if (IS_ERR(typec_sw->sw)) {
+		dev_err(dev, "Error registering typec switch: %ld\n",
+			PTR_ERR(typec_sw->sw));
+		return PTR_ERR(typec_sw->sw);
+	}
+
+	return 0;
+}
+
+static int typec_switch_simple_remove(struct platform_device *pdev)
+{
+	struct typec_switch_simple *typec_sw = platform_get_drvdata(pdev);
+
+	typec_switch_unregister(typec_sw->sw);
+
+	return 0;
+}
+
+static const struct of_device_id of_typec_switch_simple_match[] = {
+	{ .compatible = "typec-orientation-switch" },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, of_typec_switch_simple_match);
+
+static struct platform_driver typec_switch_simple_driver = {
+	.probe		= typec_switch_simple_probe,
+	.remove		= typec_switch_simple_remove,
+	.driver		= {
+		.name	= "typec-switch-simple",
+		.of_match_table = of_typec_switch_simple_match,
+	},
+};
+
+module_platform_driver(typec_switch_simple_driver);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("TypeC Orientation Switch Simple driver");
+MODULE_AUTHOR("Jun Li <jun.li@nxp.com>");
-- 
2.7.4