diff mbox series

[v4,4/4] usb: typec: mux: add typec switch simple driver

Message ID 1603098195-9923-4-git-send-email-jun.li@nxp.com
State New
Headers show
Series [v4,1/4] dt-bindings: usb: add documentation for typec switch simple driver | expand

Commit Message

Jun Li Oct. 19, 2020, 9:03 a.m. UTC
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 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         |   6 ++
 drivers/usb/typec/mux/Makefile        |   1 +
 drivers/usb/typec/mux/switch-simple.c | 110 ++++++++++++++++++++++++++++++++++
 3 files changed, 117 insertions(+)

Comments

Andy Shevchenko Oct. 19, 2020, 12:31 p.m. UTC | #1
On Mon, Oct 19, 2020 at 05:03:15PM +0800, Li Jun wrote:
> 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.

...

>  	  Driver for USB muxes controlled by Intel PMC FW. Intel PMC FW can
>  	  control the USB role switch and also the multiplexer/demultiplexer
>  	  switches used with USB Type-C Alternate Modes.

Missed blank line.

> +config TYPEC_SWITCH_SIMPLE
> +	tristate "Type-c orientation switch Simple driver"

Type-c -> Type-C

Simple -> simple


> +	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.

Driver name?

...

> +/**

Is it kernel doc?!

> + * switch-simple.c - typec switch simple control.

Remove file name from the file.

> + *
> + * Copyright 2020 NXP
> + * Author: Jun Li <jun.li@nxp.com>

> + *

Redundant blank line.

> + */

...

> +#include <linux/of.h>
> +#include <linux/of_gpio.h>

No evidence of use of these headers, but
mod_devicetable.h along with gpio/consumer.h are missed.


...

> +	switch (orientation) {
> +	case TYPEC_ORIENTATION_NORMAL:
> +		if (typec_sw->sel_gpio)

Optional GPIO does not require these checks. Drop them and learn what "optional" means.

> +			gpiod_set_value_cansleep(typec_sw->sel_gpio, 1);
> +		break;
> +	case TYPEC_ORIENTATION_REVERSE:
> +		if (typec_sw->sel_gpio)
> +			gpiod_set_value_cansleep(typec_sw->sel_gpio, 0);
> +		break;
> +	case TYPEC_ORIENTATION_NONE:
> +		break;
> +	}

...

> +	struct typec_switch_simple	*typec_sw;
> +	struct device			*dev = &pdev->dev;
> +	struct typec_switch_desc sw_desc;

Be consistent with indentation.

...

> +	/* Get the super speed active channel selection GPIO */
> +	typec_sw->sel_gpio = devm_gpiod_get_optional(dev, "switch",
> +						     GPIOD_OUT_LOW);

It can be one line.

> +	if (IS_ERR(typec_sw->sel_gpio))
> +		return PTR_ERR(typec_sw->sel_gpio);
Jun Li Oct. 20, 2020, 12:48 p.m. UTC | #2
> -----Original Message-----
> From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Sent: Monday, October 19, 2020 8:31 PM
> To: Jun Li <jun.li@nxp.com>
> Cc: heikki.krogerus@linux.intel.com; robh+dt@kernel.org;
> rafael@kernel.org; gregkh@linuxfoundation.org; hdegoede@redhat.com;
> lee.jones@linaro.org; mika.westerberg@linux.intel.com;
> dmitry.torokhov@gmail.com; prabhakar.mahadev-lad.rj@bp.renesas.com;
> laurent.pinchart+renesas@ideasonboard.com; linux-usb@vger.kernel.org;
> devicetree@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>; Peter Chen
> <peter.chen@nxp.com>
> Subject: Re: [PATCH v4 4/4] usb: typec: mux: add typec switch simple driver
> 
> On Mon, Oct 19, 2020 at 05:03:15PM +0800, Li Jun wrote:
> > 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.
> 
> ...
> 
> >  	  Driver for USB muxes controlled by Intel PMC FW. Intel PMC FW can
> >  	  control the USB role switch and also the multiplexer/demultiplexer
> >  	  switches used with USB Type-C Alternate Modes.
> 
> Missed blank line.

Will add.

> 
> > +config TYPEC_SWITCH_SIMPLE
> > +	tristate "Type-c orientation switch Simple driver"
> 
> Type-c -> Type-C
> 
> Simple -> simple

Will change.

> 
> 
> > +	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.
> 
> Driver name?

Will add the driver module name.

> 
> ...
> 
> > +/**
> 
> Is it kernel doc?!

Will change to "/*"

> 
> > + * switch-simple.c - typec switch simple control.
> 
> Remove file name from the file.

Will remove it.
> 
> > + *
> > + * Copyright 2020 NXP
> > + * Author: Jun Li <jun.li@nxp.com>
> 
> > + *
> 
> Redundant blank line.

Will remove.

> 
> > + */
> 
> ...
> 
> > +#include <linux/of.h>
> > +#include <linux/of_gpio.h>
> 
> No evidence of use of these headers, but mod_devicetable.h along with
> gpio/consumer.h are missed.

Thanks, will change.

> 
> 
> ...
> 
> > +	switch (orientation) {
> > +	case TYPEC_ORIENTATION_NORMAL:
> > +		if (typec_sw->sel_gpio)
> 
> Optional GPIO does not require these checks. Drop them and learn what
> "optional" means.

Checked, will drop those checks.

> 
> > +			gpiod_set_value_cansleep(typec_sw->sel_gpio, 1);
> > +		break;
> > +	case TYPEC_ORIENTATION_REVERSE:
> > +		if (typec_sw->sel_gpio)
> > +			gpiod_set_value_cansleep(typec_sw->sel_gpio, 0);
> > +		break;
> > +	case TYPEC_ORIENTATION_NONE:
> > +		break;
> > +	}
> 
> ...
> 
> > +	struct typec_switch_simple	*typec_sw;
> > +	struct device			*dev = &pdev->dev;
> > +	struct typec_switch_desc sw_desc;
> 
> Be consistent with indentation.

Wil change.

> 
> ...
> 
> > +	/* Get the super speed active channel selection GPIO */
> > +	typec_sw->sel_gpio = devm_gpiod_get_optional(dev, "switch",
> > +						     GPIOD_OUT_LOW);
> 
> It can be one line.

Will change.

Thanks
Li Jun
> 
> > +	if (IS_ERR(typec_sw->sel_gpio))
> > +		return PTR_ERR(typec_sw->sel_gpio);
> 
> --
> With Best Regards,
> Andy Shevchenko
>
Dmitry Torokhov Oct. 21, 2020, 7:55 p.m. UTC | #3
Hi,

On Mon, Oct 19, 2020 at 05:03:15PM +0800, Li Jun wrote:
> +
> +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);
> +
> +	mutex_lock(&typec_sw->lock);

Why is this lock needed? It looks like we are passing requests directly
to gpiochip which I expect would take care of this.

> +
> +	switch (orientation) {
> +	case TYPEC_ORIENTATION_NORMAL:
> +		if (typec_sw->sel_gpio)
> +			gpiod_set_value_cansleep(typec_sw->sel_gpio, 1);
> +		break;
> +	case TYPEC_ORIENTATION_REVERSE:
> +		if (typec_sw->sel_gpio)
> +			gpiod_set_value_cansleep(typec_sw->sel_gpio, 0);
> +		break;
> +	case TYPEC_ORIENTATION_NONE:
> +		break;
> +	}
> +
> +	mutex_unlock(&typec_sw->lock);
> +
> +	return 0;
> +}
> +
> +static int typec_switch_simple_probe(struct platform_device *pdev)
> +{
> +	struct typec_switch_simple	*typec_sw;
> +	struct device			*dev = &pdev->dev;
> +	struct typec_switch_desc sw_desc;
> +
> +	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;
> +	mutex_init(&typec_sw->lock);
> +
> +	/* Get the super speed active channel selection GPIO */
> +	typec_sw->sel_gpio = devm_gpiod_get_optional(dev, "switch",
> +						     GPIOD_OUT_LOW);

Does this driver make sense without the GPIO? Should it be made
mandatory?

Thanks.
Jun Li Oct. 22, 2020, 11:52 a.m. UTC | #4
> -----Original Message-----
> From: dmitry.torokhov@gmail.com <dmitry.torokhov@gmail.com>
> Sent: Thursday, October 22, 2020 3:56 AM
> To: Jun Li <jun.li@nxp.com>
> Cc: heikki.krogerus@linux.intel.com; robh+dt@kernel.org;
> rafael@kernel.org; gregkh@linuxfoundation.org;
> andriy.shevchenko@linux.intel.com; hdegoede@redhat.com;
> lee.jones@linaro.org; mika.westerberg@linux.intel.com;
> prabhakar.mahadev-lad.rj@bp.renesas.com;
> laurent.pinchart+renesas@ideasonboard.com; linux-usb@vger.kernel.org;
> devicetree@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>; Peter Chen
> <peter.chen@nxp.com>
> Subject: Re: [PATCH v4 4/4] usb: typec: mux: add typec switch simple driver
> 
> Hi,
> 
> On Mon, Oct 19, 2020 at 05:03:15PM +0800, Li Jun wrote:
> > +
> > +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);
> > +
> > +	mutex_lock(&typec_sw->lock);
> 
> Why is this lock needed? It looks like we are passing requests directly to
> gpiochip which I expect would take care of this.

Checked some gpiochips, looks like with only GPIO, yes, this lock is not required,
I will remove it.

> 
> > +
> > +	switch (orientation) {
> > +	case TYPEC_ORIENTATION_NORMAL:
> > +		if (typec_sw->sel_gpio)
> > +			gpiod_set_value_cansleep(typec_sw->sel_gpio, 1);
> > +		break;
> > +	case TYPEC_ORIENTATION_REVERSE:
> > +		if (typec_sw->sel_gpio)
> > +			gpiod_set_value_cansleep(typec_sw->sel_gpio, 0);
> > +		break;
> > +	case TYPEC_ORIENTATION_NONE:
> > +		break;
> > +	}
> > +
> > +	mutex_unlock(&typec_sw->lock);
> > +
> > +	return 0;
> > +}
> > +
> > +static int typec_switch_simple_probe(struct platform_device *pdev) {
> > +	struct typec_switch_simple	*typec_sw;
> > +	struct device			*dev = &pdev->dev;
> > +	struct typec_switch_desc sw_desc;
> > +
> > +	typec_sw = devm_kzalloc(dev, sizeof(*typec_sw), GFP_KERNEL);
> > +	if (!typec_sw)
> > +		return -ENOMEM;
> > +q
> > +	platform_set_drvdata(pdev, typec_sw);
> > +
> > +	sw_desc.drvdata = typec_sw;
> > +	sw_desc.fwnode = dev->fwnode;
> > +	sw_desc.set = typec_switch_simple_set;
> > +	mutex_init(&typec_sw->lock);
> > +
> > +	/* Get the super speed active channel selection GPIO */
> > +	typec_sw->sel_gpio = devm_gpiod_get_optional(dev, "switch",
> > +						     GPIOD_OUT_LOW);
> 
> Does this driver make sense without the GPIO? Should it be made mandatory?

My old version made it to be mandatory, I change it to be optional in this version
for possible extend to other simple typec switch design which do not use GPIO as
this is going to be a generic typec switch driver. yes, for current implementation,
this driver will only register a typec switch in sys if without GPIO provided.

Li Jun

> 
> Thanks.
> 
> --
> Dmitry
diff mbox series

Patch

diff --git a/drivers/usb/typec/mux/Kconfig b/drivers/usb/typec/mux/Kconfig
index a4dbd11..2942588 100644
--- a/drivers/usb/typec/mux/Kconfig
+++ b/drivers/usb/typec/mux/Kconfig
@@ -17,5 +17,11 @@  config TYPEC_MUX_INTEL_PMC
 	  Driver for USB muxes controlled by Intel PMC FW. Intel PMC FW can
 	  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.
 
 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..98f4b49
--- /dev/null
+++ b/drivers/usb/typec/mux/switch-simple.c
@@ -0,0 +1,110 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * switch-simple.c - typec switch simple control.
+ *
+ * Copyright 2020 NXP
+ * Author: Jun Li <jun.li@nxp.com>
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/usb/typec_mux.h>
+
+struct typec_switch_simple {
+	struct typec_switch *sw;
+	struct mutex lock;
+	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);
+
+	mutex_lock(&typec_sw->lock);
+
+	switch (orientation) {
+	case TYPEC_ORIENTATION_NORMAL:
+		if (typec_sw->sel_gpio)
+			gpiod_set_value_cansleep(typec_sw->sel_gpio, 1);
+		break;
+	case TYPEC_ORIENTATION_REVERSE:
+		if (typec_sw->sel_gpio)
+			gpiod_set_value_cansleep(typec_sw->sel_gpio, 0);
+		break;
+	case TYPEC_ORIENTATION_NONE:
+		break;
+	}
+
+	mutex_unlock(&typec_sw->lock);
+
+	return 0;
+}
+
+static int typec_switch_simple_probe(struct platform_device *pdev)
+{
+	struct typec_switch_simple	*typec_sw;
+	struct device			*dev = &pdev->dev;
+	struct typec_switch_desc sw_desc;
+
+	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;
+	mutex_init(&typec_sw->lock);
+
+	/* 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>");