[PATCH v3] extcon: add Maxim MAX3355 driver

[PATCH v3] extcon: add Maxim MAX3355 driver

[Sergei Shtylyov]

Maxim Integrated MAX3355E chip integrates a charge pump and comparators to
enable a system with an integrated USB OTG dual-role transceiver to
function as an USB OTG dual-role device. In addition to sensing/controlling
Vbus, the chip also passes thru the ID signal from the USB OTG connector.
On some Renesas boards, this signal is just fed into the SoC thru a GPIO
pin -- there's no real OTG controller, only host and gadget USB controllers
sharing the same USB bus; however, we'd like to allow host or gadget
drivers to be loaded depending on the cable type, hence the need for the
MAX3355 extcon driver. The Vbus status signals are also wired to GPIOs
(however, we aren't currently interested in them), the OFFVBUS# signal is
controlled by the host controllers, there's also the SHDN# signal wired to
a GPIO, it should be driven high for the normal operation.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

---
Changes in version 3:
- reformatted the change log.

Changes in version 2:
- added the USB gadget cable support;
- added the remove() driver method which drives SHDN# GPIO low to save power;
- dropped vendor prefix from the ID GPIO property name;
- changed the GPIO property name suffix to "-gpios";
- switched to usign extcon_set_cable_state_() API;
- switched to using the gpiod/sleeping 'gpiolib' APIs;
- addded error messages to max3355_probe();
- added IRQF_NO_SUSPEND flasg to the devm_request_threaded_irq() call;
- renamed 'ret' variable to 'err' in max3355_probe();
- expanded the Kconfig entry help text;
- added vendor name to the patch summary, the bindings document, the Kconfig
  entry, the driver heading comment, the module description, and the change log;
- fixed up and reformatted the change log.

 Documentation/devicetree/bindings/extcon/extcon-max3355.txt |   21 +
 drivers/extcon/Kconfig                                      |    8 
 drivers/extcon/Makefile                                     |    1 
 drivers/extcon/extcon-max3355.c                             |  153 ++++++++++++
 4 files changed, 183 insertions(+)

Index: renesas/Documentation/devicetree/bindings/extcon/extcon-max3355.txt
===================================================================
--- /dev/null
+++ renesas/Documentation/devicetree/bindings/extcon/extcon-max3355.txt
@@ -0,0 +1,21 @@
+Maxim Integrated MAX3355 USB OTG chip
+-------------------------------------
+
+MAX3355 integrates a charge pump and comparators to enable a system with an
+integrated USB OTG dual-role transceiver to function as a USB OTG dual-role
+device.
+
+Required properties:
+- compatible: should be "maxim,max3355";
+- maxim,shdn-gpios: should contain a phandle and GPIO specifier for the GPIO pin
+  connected to the MAX3355's SHDN# pin;
+- id-gpios: should contain a phandle and GPIO specifier for the GPIO pin
+  connected to the MAX3355's ID_OUT pin.
+
+Example (Koelsch board):
+
+	usb-otg {
+		compatible = "maxim,max3355";
+		maxim,shdn-gpios = <&gpio2 4 GPIO_ACTIVE_LOW>;
+		id-gpios = <&gpio5 31 GPIO_ACTIVE_HIGH>;
+	};
Index: renesas/drivers/extcon/Kconfig
===================================================================
--- renesas.orig/drivers/extcon/Kconfig
+++ renesas/drivers/extcon/Kconfig
@@ -52,6 +52,14 @@ config EXTCON_MAX14577
 	  Maxim MAX14577/77836. The MAX14577/77836 MUIC is a USB port accessory
 	  detector and switch.
 
+config EXTCON_MAX3355
+	tristate "Maxim MAX3355 USB OTG EXTCON Support"
+	help
+	  If you say yes here you get support for the USB OTG role detection by
+	  MAX3355. The MAX3355 chip integrates a charge pump and comparators to
+	  enable a system with an integrated USB OTG dual-role transceiver to
+	  function as an USB OTG dual-role device.
+
 config EXTCON_MAX77693
 	tristate "Maxim MAX77693 EXTCON Support"
 	depends on MFD_MAX77693 && INPUT
Index: renesas/drivers/extcon/Makefile
===================================================================
--- renesas.orig/drivers/extcon/Makefile
+++ renesas/drivers/extcon/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_EXTCON_ARIZONA)	+= extcon-a
 obj-$(CONFIG_EXTCON_AXP288)	+= extcon-axp288.o
 obj-$(CONFIG_EXTCON_GPIO)	+= extcon-gpio.o
 obj-$(CONFIG_EXTCON_MAX14577)	+= extcon-max14577.o
+obj-$(CONFIG_EXTCON_MAX3355)	+= extcon-max3355.o
 obj-$(CONFIG_EXTCON_MAX77693)	+= extcon-max77693.o
 obj-$(CONFIG_EXTCON_MAX77843)	+= extcon-max77843.o
 obj-$(CONFIG_EXTCON_MAX8997)	+= extcon-max8997.o
Index: renesas/drivers/extcon/extcon-max3355.c
===================================================================
--- /dev/null
+++ renesas/drivers/extcon/extcon-max3355.c
@@ -0,0 +1,153 @@
+/*
+ * Maxim Integrated MAX3355 USB OTG chip extcon driver
+ *
+ * Copyright (C) 2014 Cogent Embedded, Inc.
+ * Author: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ */
+
+#include <linux/extcon.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+struct max3355_data {
+	struct extcon_dev *edev;
+	struct gpio_desc *id_gpiod;
+	struct gpio_desc *shdn_gpiod;
+};
+
+static const unsigned int max3355_cable[] = {
+	EXTCON_USB,
+	EXTCON_USB_HOST,
+	EXTCON_NONE,
+};
+
+static irqreturn_t max3355_id_irq(int irq, void *dev_id)
+{
+	struct max3355_data *data = dev_id;
+	int id = gpiod_get_value_cansleep(data->id_gpiod);
+
+	if (id) {
+		/*
+		 * ID = 1 means USB HOST cable detached.
+		 * As we don't have event for USB peripheral cable attached,
+		 * we simulate USB peripheral attach here.
+		 */
+		extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, false);
+		extcon_set_cable_state_(data->edev, EXTCON_USB, true);
+	} else {
+		/*
+		 * ID = 0 means USB HOST cable attached.
+		 * As we don't have event for USB peripheral cable detached,
+		 * we simulate USB peripheral detach here.
+		 */
+		extcon_set_cable_state_(data->edev, EXTCON_USB, false);
+		extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, true);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int max3355_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct max3355_data *data;
+	struct gpio_desc *gpiod;
+	int irq, err;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
+	if (IS_ERR(data->edev)) {
+		dev_err(&pdev->dev, "failed to allocate extcon device\n");
+		return PTR_ERR(data->edev);
+	}
+	data->edev->name = kstrdup(np->name, GFP_KERNEL);
+
+	gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
+	if (IS_ERR(gpiod)) {
+		dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
+		return PTR_ERR(gpiod);
+	}
+	data->id_gpiod = gpiod;
+
+	gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpiod)) {
+		dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
+		return PTR_ERR(gpiod);
+	}
+	data->shdn_gpiod = gpiod;
+
+	err = devm_extcon_dev_register(&pdev->dev, data->edev);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to register extcon device\n");
+		return err;
+	}
+
+	irq = gpiod_to_irq(data->id_gpiod);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
+		return irq;
+	}
+
+	err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
+					IRQF_ONESHOT | IRQF_NO_SUSPEND |
+					IRQF_TRIGGER_RISING |
+					IRQF_TRIGGER_FALLING,
+					pdev->name, data);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
+		return err;
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	/* Perform initial detection */
+	max3355_id_irq(irq, data);
+
+	return 0;
+}
+
+static int max3355_remove(struct platform_device *pdev)
+{
+	struct max3355_data *data = platform_get_drvdata(pdev);
+
+	gpiod_set_value_cansleep(data->shdn_gpiod, 0);
+
+	return 0;
+}
+
+static const struct of_device_id max3355_match_table[] = {
+	{ .compatible = "maxim,max3355", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max3355_match_table);
+
+static struct platform_driver max3355_driver = {
+	.probe		= max3355_probe,
+	.remove		= max3355_remove,
+	.driver		= {
+		.name	= "extcon-max3355",
+		.of_match_table = max3355_match_table,
+		.owner	= THIS_MODULE,
+	},
+};
+
+module_platform_driver(max3355_driver);
+
+MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
+MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
+MODULE_LICENSE("GPL v2");

Re: [PATCH v3] extcon: add Maxim MAX3355 driver

[Krzysztof Kozlowski]

2015-12-17 3:07 GMT+09:00 Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>:
> Maxim Integrated MAX3355E chip integrates a charge pump and comparators to
> enable a system with an integrated USB OTG dual-role transceiver to
> function as an USB OTG dual-role device. In addition to sensing/controlling
> Vbus, the chip also passes thru the ID signal from the USB OTG connector.
> On some Renesas boards, this signal is just fed into the SoC thru a GPIO
> pin -- there's no real OTG controller, only host and gadget USB controllers
> sharing the same USB bus; however, we'd like to allow host or gadget
> drivers to be loaded depending on the cable type, hence the need for the
> MAX3355 extcon driver. The Vbus status signals are also wired to GPIOs
> (however, we aren't currently interested in them), the OFFVBUS# signal is
> controlled by the host controllers, there's also the SHDN# signal wired to
> a GPIO, it should be driven high for the normal operation.
>
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>
> ---
> Changes in version 3:
> - reformatted the change log.
>
> Changes in version 2:
> - added the USB gadget cable support;
> - added the remove() driver method which drives SHDN# GPIO low to save power;
> - dropped vendor prefix from the ID GPIO property name;
> - changed the GPIO property name suffix to "-gpios";
> - switched to usign extcon_set_cable_state_() API;
> - switched to using the gpiod/sleeping 'gpiolib' APIs;
> - addded error messages to max3355_probe();
> - added IRQF_NO_SUSPEND flasg to the devm_request_threaded_irq() call;
> - renamed 'ret' variable to 'err' in max3355_probe();
> - expanded the Kconfig entry help text;
> - added vendor name to the patch summary, the bindings document, the Kconfig
>   entry, the driver heading comment, the module description, and the change log;
> - fixed up and reformatted the change log.
>
>  Documentation/devicetree/bindings/extcon/extcon-max3355.txt |   21 +
>  drivers/extcon/Kconfig                                      |    8
>  drivers/extcon/Makefile                                     |    1
>  drivers/extcon/extcon-max3355.c                             |  153 ++++++++++++
>  4 files changed, 183 insertions(+)
>
> Index: renesas/Documentation/devicetree/bindings/extcon/extcon-max3355.txt
> ===================================================================
> --- /dev/null
> +++ renesas/Documentation/devicetree/bindings/extcon/extcon-max3355.txt
> @@ -0,0 +1,21 @@
> +Maxim Integrated MAX3355 USB OTG chip
> +-------------------------------------
> +
> +MAX3355 integrates a charge pump and comparators to enable a system with an
> +integrated USB OTG dual-role transceiver to function as a USB OTG dual-role
> +device.
> +
> +Required properties:
> +- compatible: should be "maxim,max3355";
> +- maxim,shdn-gpios: should contain a phandle and GPIO specifier for the GPIO pin
> +  connected to the MAX3355's SHDN# pin;

Could you add some indentation to the wrapped line for this property?
For readability.

> +- id-gpios: should contain a phandle and GPIO specifier for the GPIO pin
> +  connected to the MAX3355's ID_OUT pin.

Ditto.

Why this property lacks the vendor prefix i(n comparison to shdn-gpios
which has the prefix)?

> +
> +Example (Koelsch board):
> +
> +       usb-otg {
> +               compatible = "maxim,max3355";
> +               maxim,shdn-gpios = <&gpio2 4 GPIO_ACTIVE_LOW>;
> +               id-gpios = <&gpio5 31 GPIO_ACTIVE_HIGH>;
> +       };
> Index: renesas/drivers/extcon/Kconfig
> ===================================================================
> --- renesas.orig/drivers/extcon/Kconfig
> +++ renesas/drivers/extcon/Kconfig
> @@ -52,6 +52,14 @@ config EXTCON_MAX14577
>           Maxim MAX14577/77836. The MAX14577/77836 MUIC is a USB port accessory
>           detector and switch.
>
> +config EXTCON_MAX3355
> +       tristate "Maxim MAX3355 USB OTG EXTCON Support"
> +       help
> +         If you say yes here you get support for the USB OTG role detection by
> +         MAX3355. The MAX3355 chip integrates a charge pump and comparators to
> +         enable a system with an integrated USB OTG dual-role transceiver to
> +         function as an USB OTG dual-role device.
> +
>  config EXTCON_MAX77693
>         tristate "Maxim MAX77693 EXTCON Support"
>         depends on MFD_MAX77693 && INPUT
> Index: renesas/drivers/extcon/Makefile
> ===================================================================
> --- renesas.orig/drivers/extcon/Makefile
> +++ renesas/drivers/extcon/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_EXTCON_ARIZONA)    += extcon-a
>  obj-$(CONFIG_EXTCON_AXP288)    += extcon-axp288.o
>  obj-$(CONFIG_EXTCON_GPIO)      += extcon-gpio.o
>  obj-$(CONFIG_EXTCON_MAX14577)  += extcon-max14577.o
> +obj-$(CONFIG_EXTCON_MAX3355)   += extcon-max3355.o
>  obj-$(CONFIG_EXTCON_MAX77693)  += extcon-max77693.o
>  obj-$(CONFIG_EXTCON_MAX77843)  += extcon-max77843.o
>  obj-$(CONFIG_EXTCON_MAX8997)   += extcon-max8997.o
> Index: renesas/drivers/extcon/extcon-max3355.c
> ===================================================================
> --- /dev/null
> +++ renesas/drivers/extcon/extcon-max3355.c
> @@ -0,0 +1,153 @@
> +/*
> + * Maxim Integrated MAX3355 USB OTG chip extcon driver
> + *
> + * Copyright (C) 2014 Cogent Embedded, Inc.
> + * Author: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + */
> +
> +#include <linux/extcon.h>
> +#include <linux/gpio.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_gpio.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/workqueue.h>
> +
> +struct max3355_data {
> +       struct extcon_dev *edev;
> +       struct gpio_desc *id_gpiod;
> +       struct gpio_desc *shdn_gpiod;
> +};
> +
> +static const unsigned int max3355_cable[] = {
> +       EXTCON_USB,
> +       EXTCON_USB_HOST,
> +       EXTCON_NONE,
> +};
> +
> +static irqreturn_t max3355_id_irq(int irq, void *dev_id)
> +{
> +       struct max3355_data *data = dev_id;
> +       int id = gpiod_get_value_cansleep(data->id_gpiod);
> +
> +       if (id) {
> +               /*
> +                * ID = 1 means USB HOST cable detached.
> +                * As we don't have event for USB peripheral cable attached,
> +                * we simulate USB peripheral attach here.
> +                */
> +               extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, false);
> +               extcon_set_cable_state_(data->edev, EXTCON_USB, true);
> +       } else {
> +               /*
> +                * ID = 0 means USB HOST cable attached.
> +                * As we don't have event for USB peripheral cable detached,
> +                * we simulate USB peripheral detach here.
> +                */
> +               extcon_set_cable_state_(data->edev, EXTCON_USB, false);
> +               extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, true);
> +       }
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static int max3355_probe(struct platform_device *pdev)
> +{
> +       struct device_node *np = pdev->dev.of_node;
> +       struct max3355_data *data;
> +       struct gpio_desc *gpiod;
> +       int irq, err;
> +
> +       data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
> +                           GFP_KERNEL);
> +       if (!data)
> +               return -ENOMEM;
> +
> +       data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
> +       if (IS_ERR(data->edev)) {
> +               dev_err(&pdev->dev, "failed to allocate extcon device\n");
> +               return PTR_ERR(data->edev);
> +       }
> +       data->edev->name = kstrdup(np->name, GFP_KERNEL);

I think it is not needed any more (extcon_dev_register()) will set it.
Anyway there is no checking for NULL return value and no freeing in
error/exit paths.

> +
> +       gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
> +       if (IS_ERR(gpiod)) {
> +               dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
> +               return PTR_ERR(gpiod);
> +       }
> +       data->id_gpiod = gpiod;
> +
> +       gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);
> +       if (IS_ERR(gpiod)) {
> +               dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
> +               return PTR_ERR(gpiod);
> +       }
> +       data->shdn_gpiod = gpiod;
> +
> +       err = devm_extcon_dev_register(&pdev->dev, data->edev);
> +       if (err < 0) {
> +               dev_err(&pdev->dev, "failed to register extcon device\n");
> +               return err;
> +       }
> +
> +       irq = gpiod_to_irq(data->id_gpiod);
> +       if (irq < 0) {
> +               dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
> +               return irq;
> +       }
> +
> +       err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
> +                                       IRQF_ONESHOT | IRQF_NO_SUSPEND |
> +                                       IRQF_TRIGGER_RISING |
> +                                       IRQF_TRIGGER_FALLING,
> +                                       pdev->name, data);
> +       if (err < 0) {
> +               dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
> +               return err;
> +       }
> +
> +       platform_set_drvdata(pdev, data);
> +
> +       /* Perform initial detection */
> +       max3355_id_irq(irq, data);
> +
> +       return 0;
> +}
> +
> +static int max3355_remove(struct platform_device *pdev)
> +{
> +       struct max3355_data *data = platform_get_drvdata(pdev);
> +
> +       gpiod_set_value_cansleep(data->shdn_gpiod, 0);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id max3355_match_table[] = {
> +       { .compatible = "maxim,max3355", },
> +       { }
> +};
> +MODULE_DEVICE_TABLE(of, max3355_match_table);
> +
> +static struct platform_driver max3355_driver = {
> +       .probe          = max3355_probe,
> +       .remove         = max3355_remove,
> +       .driver         = {
> +               .name   = "extcon-max3355",
> +               .of_match_table = max3355_match_table,
> +               .owner  = THIS_MODULE,

No need for owner.
Please pass the source through recent coccicheck and fix the findings.

Best regards,
Krzysztof

Re: [PATCH v3] extcon: add Maxim MAX3355 driver

[Chanwoo Choi]

Hi Sergei,

On 2015년 12월 17일 03:07, Sergei Shtylyov wrote:
> Maxim Integrated MAX3355E chip integrates a charge pump and comparators to
> enable a system with an integrated USB OTG dual-role transceiver to
> function as an USB OTG dual-role device. In addition to sensing/controlling
> Vbus, the chip also passes thru the ID signal from the USB OTG connector.
> On some Renesas boards, this signal is just fed into the SoC thru a GPIO
> pin -- there's no real OTG controller, only host and gadget USB controllers
> sharing the same USB bus; however, we'd like to allow host or gadget
> drivers to be loaded depending on the cable type, hence the need for the
> MAX3355 extcon driver. The Vbus status signals are also wired to GPIOs
> (however, we aren't currently interested in them), the OFFVBUS# signal is
> controlled by the host controllers, there's also the SHDN# signal wired to
> a GPIO, it should be driven high for the normal operation.
> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> 
> ---
> Changes in version 3:
> - reformatted the change log.
> 
> Changes in version 2:
> - added the USB gadget cable support;
> - added the remove() driver method which drives SHDN# GPIO low to save power;
> - dropped vendor prefix from the ID GPIO property name;
> - changed the GPIO property name suffix to "-gpios";
> - switched to usign extcon_set_cable_state_() API;
> - switched to using the gpiod/sleeping 'gpiolib' APIs;
> - addded error messages to max3355_probe();
> - added IRQF_NO_SUSPEND flasg to the devm_request_threaded_irq() call;
> - renamed 'ret' variable to 'err' in max3355_probe();
> - expanded the Kconfig entry help text;
> - added vendor name to the patch summary, the bindings document, the Kconfig
>   entry, the driver heading comment, the module description, and the change log;
> - fixed up and reformatted the change log.
> 
>  Documentation/devicetree/bindings/extcon/extcon-max3355.txt |   21 +
>  drivers/extcon/Kconfig                                      |    8 
>  drivers/extcon/Makefile                                     |    1 
>  drivers/extcon/extcon-max3355.c                             |  153 ++++++++++++
>  4 files changed, 183 insertions(+)
> 
> Index: renesas/Documentation/devicetree/bindings/extcon/extcon-max3355.txt
> ===================================================================
> --- /dev/null
> +++ renesas/Documentation/devicetree/bindings/extcon/extcon-max3355.txt
> @@ -0,0 +1,21 @@
> +Maxim Integrated MAX3355 USB OTG chip
> +-------------------------------------
> +
> +MAX3355 integrates a charge pump and comparators to enable a system with an
> +integrated USB OTG dual-role transceiver to function as a USB OTG dual-role
> +device.
> +
> +Required properties:
> +- compatible: should be "maxim,max3355";
> +- maxim,shdn-gpios: should contain a phandle and GPIO specifier for the GPIO pin
> +  connected to the MAX3355's SHDN# pin;
> +- id-gpios: should contain a phandle and GPIO specifier for the GPIO pin
> +  connected to the MAX3355's ID_OUT pin.
> +
> +Example (Koelsch board):
> +
> +	usb-otg {
> +		compatible = "maxim,max3355";
> +		maxim,shdn-gpios = <&gpio2 4 GPIO_ACTIVE_LOW>;
> +		id-gpios = <&gpio5 31 GPIO_ACTIVE_HIGH>;
> +	};
> Index: renesas/drivers/extcon/Kconfig
> ===================================================================
> --- renesas.orig/drivers/extcon/Kconfig
> +++ renesas/drivers/extcon/Kconfig
> @@ -52,6 +52,14 @@ config EXTCON_MAX14577
>  	  Maxim MAX14577/77836. The MAX14577/77836 MUIC is a USB port accessory
>  	  detector and switch.
>  
> +config EXTCON_MAX3355
> +	tristate "Maxim MAX3355 USB OTG EXTCON Support"
> +	help
> +	  If you say yes here you get support for the USB OTG role detection by
> +	  MAX3355. The MAX3355 chip integrates a charge pump and comparators to
> +	  enable a system with an integrated USB OTG dual-role transceiver to
> +	  function as an USB OTG dual-role device.
> +
>  config EXTCON_MAX77693
>  	tristate "Maxim MAX77693 EXTCON Support"
>  	depends on MFD_MAX77693 && INPUT
> Index: renesas/drivers/extcon/Makefile
> ===================================================================
> --- renesas.orig/drivers/extcon/Makefile
> +++ renesas/drivers/extcon/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_EXTCON_ARIZONA)	+= extcon-a
>  obj-$(CONFIG_EXTCON_AXP288)	+= extcon-axp288.o
>  obj-$(CONFIG_EXTCON_GPIO)	+= extcon-gpio.o
>  obj-$(CONFIG_EXTCON_MAX14577)	+= extcon-max14577.o
> +obj-$(CONFIG_EXTCON_MAX3355)	+= extcon-max3355.o
>  obj-$(CONFIG_EXTCON_MAX77693)	+= extcon-max77693.o
>  obj-$(CONFIG_EXTCON_MAX77843)	+= extcon-max77843.o
>  obj-$(CONFIG_EXTCON_MAX8997)	+= extcon-max8997.o
> Index: renesas/drivers/extcon/extcon-max3355.c
> ===================================================================
> --- /dev/null
> +++ renesas/drivers/extcon/extcon-max3355.c
> @@ -0,0 +1,153 @@
> +/*
> + * Maxim Integrated MAX3355 USB OTG chip extcon driver
> + *
> + * Copyright (C) 2014 Cogent Embedded, Inc.

2014 -> 2015

> + * Author: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + */
> +
> +#include <linux/extcon.h>
> +#include <linux/gpio.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_gpio.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/workqueue.h>
> +
> +struct max3355_data {
> +	struct extcon_dev *edev;
> +	struct gpio_desc *id_gpiod;
> +	struct gpio_desc *shdn_gpiod;
> +};
> +
> +static const unsigned int max3355_cable[] = {
> +	EXTCON_USB,
> +	EXTCON_USB_HOST,
> +	EXTCON_NONE,
> +};
> +
> +static irqreturn_t max3355_id_irq(int irq, void *dev_id)
> +{
> +	struct max3355_data *data = dev_id;
> +	int id = gpiod_get_value_cansleep(data->id_gpiod);
> +
> +	if (id) {
> +		/*
> +		 * ID = 1 means USB HOST cable detached.
> +		 * As we don't have event for USB peripheral cable attached,
> +		 * we simulate USB peripheral attach here.
> +		 */
> +		extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, false);
> +		extcon_set_cable_state_(data->edev, EXTCON_USB, true);
> +	} else {
> +		/*
> +		 * ID = 0 means USB HOST cable attached.
> +		 * As we don't have event for USB peripheral cable detached,
> +		 * we simulate USB peripheral detach here.
> +		 */
> +		extcon_set_cable_state_(data->edev, EXTCON_USB, false);
> +		extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, true);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int max3355_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct max3355_data *data;
> +	struct gpio_desc *gpiod;
> +	int irq, err;
> +
> +	data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
> +			    GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
> +	if (IS_ERR(data->edev)) {
> +		dev_err(&pdev->dev, "failed to allocate extcon device\n");
> +		return PTR_ERR(data->edev);
> +	}
> +	data->edev->name = kstrdup(np->name, GFP_KERNEL);

You don't need to set the name of extcon device.
Instead, the extcon_dev_register() will set it.

> +
> +	gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
> +	if (IS_ERR(gpiod)) {
> +		dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
> +		return PTR_ERR(gpiod);
> +	}
> +	data->id_gpiod = gpiod;
> +
> +	gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);
> +	if (IS_ERR(gpiod)) {
> +		dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
> +		return PTR_ERR(gpiod);
> +	}
> +	data->shdn_gpiod = gpiod;
> +
> +	err = devm_extcon_dev_register(&pdev->dev, data->edev);
> +	if (err < 0) {
> +		dev_err(&pdev->dev, "failed to register extcon device\n");
> +		return err;
> +	}
> +
> +	irq = gpiod_to_irq(data->id_gpiod);
> +	if (irq < 0) {
> +		dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
> +		return irq;
> +	}
> +
> +	err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
> +					IRQF_ONESHOT | IRQF_NO_SUSPEND |
> +					IRQF_TRIGGER_RISING |
> +					IRQF_TRIGGER_FALLING,
> +					pdev->name, data);
> +	if (err < 0) {
> +		dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
> +		return err;
> +	}

I recommend that you reorder the init code in probe() as following:

1. Allocate the memory of max3355_data *data.
2. Parse and initialize the gpio (id, shdn)
3. Allocate the memory of extcon_dev and register it.
4. Request the interrupt.

> +
> +	platform_set_drvdata(pdev, data);
> +
> +	/* Perform initial detection */
> +	max3355_id_irq(irq, data);
> +
> +	return 0;
> +}
> +
> +static int max3355_remove(struct platform_device *pdev)
> +{
> +	struct max3355_data *data = platform_get_drvdata(pdev);
> +
> +	gpiod_set_value_cansleep(data->shdn_gpiod, 0);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id max3355_match_table[] = {
> +	{ .compatible = "maxim,max3355", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, max3355_match_table);
> +
> +static struct platform_driver max3355_driver = {
> +	.probe		= max3355_probe,
> +	.remove		= max3355_remove,
> +	.driver		= {
> +		.name	= "extcon-max3355",
> +		.of_match_table = max3355_match_table,
> +		.owner	= THIS_MODULE,

You don't need to add the 'owner'.

> +	},
> +};
> +
> +module_platform_driver(max3355_driver);
> +
> +MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
> +MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
> +MODULE_LICENSE("GPL v2");

Thanks,
Chanwoo Choi

Re: [PATCH v3] extcon: add Maxim MAX3355 driver

[Chanwoo Choi]

Hi,

On 2015년 12월 17일 11:16, Chanwoo Choi wrote:
> Hi Sergei,
> 
> On 2015년 12월 17일 03:07, Sergei Shtylyov wrote:
>> Maxim Integrated MAX3355E chip integrates a charge pump and comparators to
>> enable a system with an integrated USB OTG dual-role transceiver to
>> function as an USB OTG dual-role device. In addition to sensing/controlling
>> Vbus, the chip also passes thru the ID signal from the USB OTG connector.
>> On some Renesas boards, this signal is just fed into the SoC thru a GPIO
>> pin -- there's no real OTG controller, only host and gadget USB controllers
>> sharing the same USB bus; however, we'd like to allow host or gadget
>> drivers to be loaded depending on the cable type, hence the need for the
>> MAX3355 extcon driver. The Vbus status signals are also wired to GPIOs
>> (however, we aren't currently interested in them), the OFFVBUS# signal is
>> controlled by the host controllers, there's also the SHDN# signal wired to
>> a GPIO, it should be driven high for the normal operation.
>>
>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>
>> ---
>> Changes in version 3:
>> - reformatted the change log.
>>
>> Changes in version 2:
>> - added the USB gadget cable support;
>> - added the remove() driver method which drives SHDN# GPIO low to save power;
>> - dropped vendor prefix from the ID GPIO property name;
>> - changed the GPIO property name suffix to "-gpios";
>> - switched to usign extcon_set_cable_state_() API;
>> - switched to using the gpiod/sleeping 'gpiolib' APIs;
>> - addded error messages to max3355_probe();
>> - added IRQF_NO_SUSPEND flasg to the devm_request_threaded_irq() call;
>> - renamed 'ret' variable to 'err' in max3355_probe();
>> - expanded the Kconfig entry help text;
>> - added vendor name to the patch summary, the bindings document, the Kconfig
>>   entry, the driver heading comment, the module description, and the change log;
>> - fixed up and reformatted the change log.
>>
>>  Documentation/devicetree/bindings/extcon/extcon-max3355.txt |   21 +
>>  drivers/extcon/Kconfig                                      |    8 
>>  drivers/extcon/Makefile                                     |    1 
>>  drivers/extcon/extcon-max3355.c                             |  153 ++++++++++++
>>  4 files changed, 183 insertions(+)
>>

[snip]

>> +	return 0;
>> +}
>> +
>> +static int max3355_remove(struct platform_device *pdev)
>> +{
>> +	struct max3355_data *data = platform_get_drvdata(pdev);
>> +
>> +	gpiod_set_value_cansleep(data->shdn_gpiod, 0);

Don't need to handle the 'shdn' gpio on resume/suspend funtcion?

But, if the interrput of id gpio is used for wakeup source,
there is no reason to handle it for suspend mode.

[snip]

Thanks,
Chanwoo Choi

Re: [PATCH v3] extcon: add Maxim MAX3355 driver

[Sergei Shtylyov]

Hello.

On 12/17/2015 3:53 AM, Krzysztof Kozlowski wrote:

>> Maxim Integrated MAX3355E chip integrates a charge pump and comparators to
>> enable a system with an integrated USB OTG dual-role transceiver to
>> function as an USB OTG dual-role device. In addition to sensing/controlling
>> Vbus, the chip also passes thru the ID signal from the USB OTG connector.
>> On some Renesas boards, this signal is just fed into the SoC thru a GPIO
>> pin -- there's no real OTG controller, only host and gadget USB controllers
>> sharing the same USB bus; however, we'd like to allow host or gadget
>> drivers to be loaded depending on the cable type, hence the need for the
>> MAX3355 extcon driver. The Vbus status signals are also wired to GPIOs
>> (however, we aren't currently interested in them), the OFFVBUS# signal is
>> controlled by the host controllers, there's also the SHDN# signal wired to
>> a GPIO, it should be driven high for the normal operation.
>>
>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>
>> ---
>> Changes in version 3:
>> - reformatted the change log.
>>
>> Changes in version 2:
>> - added the USB gadget cable support;
>> - added the remove() driver method which drives SHDN# GPIO low to save power;
>> - dropped vendor prefix from the ID GPIO property name;
>> - changed the GPIO property name suffix to "-gpios";
>> - switched to usign extcon_set_cable_state_() API;
>> - switched to using the gpiod/sleeping 'gpiolib' APIs;
>> - addded error messages to max3355_probe();
>> - added IRQF_NO_SUSPEND flasg to the devm_request_threaded_irq() call;
>> - renamed 'ret' variable to 'err' in max3355_probe();
>> - expanded the Kconfig entry help text;
>> - added vendor name to the patch summary, the bindings document, the Kconfig
>>    entry, the driver heading comment, the module description, and the change log;
>> - fixed up and reformatted the change log.
>>
>>   Documentation/devicetree/bindings/extcon/extcon-max3355.txt |   21 +
>>   drivers/extcon/Kconfig                                      |    8
>>   drivers/extcon/Makefile                                     |    1
>>   drivers/extcon/extcon-max3355.c                             |  153 ++++++++++++
>>   4 files changed, 183 insertions(+)
>>
>> Index: renesas/Documentation/devicetree/bindings/extcon/extcon-max3355.txt
>> ===================================================================
>> --- /dev/null
>> +++ renesas/Documentation/devicetree/bindings/extcon/extcon-max3355.txt
>> @@ -0,0 +1,21 @@
>> +Maxim Integrated MAX3355 USB OTG chip
>> +-------------------------------------
>> +
>> +MAX3355 integrates a charge pump and comparators to enable a system with an
>> +integrated USB OTG dual-role transceiver to function as a USB OTG dual-role
>> +device.
>> +
>> +Required properties:
>> +- compatible: should be "maxim,max3355";
>> +- maxim,shdn-gpios: should contain a phandle and GPIO specifier for the GPIO pin
>> +  connected to the MAX3355's SHDN# pin;
>
> Could you add some indentation to the wrapped line for this property?
> For readability.

    If it's not indented enough, I can add more spaces/tabs.

>> +- id-gpios: should contain a phandle and GPIO specifier for the GPIO pin
>> +  connected to the MAX3355's ID_OUT pin.
>
> Ditto.
>
> Why this property lacks the vendor prefix i(n comparison to shdn-gpios
> which has the prefix)?

    Since the extcon-usb-gpio driver uses "id-gpio" prop already. I can add 
back the vendor prefix if you insist.

[...]
>> Index: renesas/drivers/extcon/extcon-max3355.c
>> ===================================================================
>> --- /dev/null
>> +++ renesas/drivers/extcon/extcon-max3355.c
>> @@ -0,0 +1,153 @@
[...]
>> +static int max3355_probe(struct platform_device *pdev)
>> +{
>> +       struct device_node *np = pdev->dev.of_node;
>> +       struct max3355_data *data;
>> +       struct gpio_desc *gpiod;
>> +       int irq, err;
>> +
>> +       data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
>> +                           GFP_KERNEL);
>> +       if (!data)
>> +               return -ENOMEM;
>> +
>> +       data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
>> +       if (IS_ERR(data->edev)) {
>> +               dev_err(&pdev->dev, "failed to allocate extcon device\n");
>> +               return PTR_ERR(data->edev);
>> +       }
>> +       data->edev->name = kstrdup(np->name, GFP_KERNEL);
>
> I think it is not needed any more (extcon_dev_register()) will set it.
> Anyway there is no checking for NULL return value and no freeing in
> error/exit paths.

    Oops, will fix.

[...]
>> +static struct platform_driver max3355_driver = {
>> +       .probe          = max3355_probe,
>> +       .remove         = max3355_remove,
>> +       .driver         = {
>> +               .name   = "extcon-max3355",
>> +               .of_match_table = max3355_match_table,
>> +               .owner  = THIS_MODULE,
>
> No need for owner.
> Please pass the source through recent coccicheck and fix the findings.

    Has it been included in the kernel source somewhere already?

> Best regards,
> Krzysztof

MBR, Sergei

Re: [PATCH v3] extcon: add Maxim MAX3355 driver

[Sergei Shtylyov]

Hello.

On 12/17/2015 05:34 AM, Chanwoo Choi wrote:

>> On 2015년 12월 17일 03:07, Sergei Shtylyov wrote:
>>> Maxim Integrated MAX3355E chip integrates a charge pump and comparators to
>>> enable a system with an integrated USB OTG dual-role transceiver to
>>> function as an USB OTG dual-role device. In addition to sensing/controlling
>>> Vbus, the chip also passes thru the ID signal from the USB OTG connector.
>>> On some Renesas boards, this signal is just fed into the SoC thru a GPIO
>>> pin -- there's no real OTG controller, only host and gadget USB controllers
>>> sharing the same USB bus; however, we'd like to allow host or gadget
>>> drivers to be loaded depending on the cable type, hence the need for the
>>> MAX3355 extcon driver. The Vbus status signals are also wired to GPIOs
>>> (however, we aren't currently interested in them), the OFFVBUS# signal is
>>> controlled by the host controllers, there's also the SHDN# signal wired to
>>> a GPIO, it should be driven high for the normal operation.
>>>
>>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>>
>>> ---
>>> Changes in version 3:
>>> - reformatted the change log.
>>>
>>> Changes in version 2:
>>> - added the USB gadget cable support;
>>> - added the remove() driver method which drives SHDN# GPIO low to save power;
>>> - dropped vendor prefix from the ID GPIO property name;
>>> - changed the GPIO property name suffix to "-gpios";
>>> - switched to usign extcon_set_cable_state_() API;
>>> - switched to using the gpiod/sleeping 'gpiolib' APIs;
>>> - addded error messages to max3355_probe();
>>> - added IRQF_NO_SUSPEND flasg to the devm_request_threaded_irq() call;
>>> - renamed 'ret' variable to 'err' in max3355_probe();
>>> - expanded the Kconfig entry help text;
>>> - added vendor name to the patch summary, the bindings document, the Kconfig
>>>    entry, the driver heading comment, the module description, and the change log;
>>> - fixed up and reformatted the change log.
>>>
>>>   Documentation/devicetree/bindings/extcon/extcon-max3355.txt |   21 +
>>>   drivers/extcon/Kconfig                                      |    8
>>>   drivers/extcon/Makefile                                     |    1
>>>   drivers/extcon/extcon-max3355.c                             |  153 ++++++++++++
>>>   4 files changed, 183 insertions(+)
>>>
>
> [snip]
>
>>> +	return 0;
>>> +}
>>> +
>>> +static int max3355_remove(struct platform_device *pdev)
>>> +{
>>> +	struct max3355_data *data = platform_get_drvdata(pdev);
>>> +
>>> +	gpiod_set_value_cansleep(data->shdn_gpiod, 0);
>
> Don't need to handle the 'shdn' gpio on resume/suspend funtcion?
>
> But, if the interrput of id gpio is used for wakeup source,
> there is no reason to handle it for suspend mode.

    You told me to pass IRQF_NO_SUSPEND to devm_request_threaded_irq(), didn't 
you?

> [snip]

> Thanks,
> Chanwoo Choi

MBR, Sergei

Re: [PATCH v3] extcon: add Maxim MAX3355 driver

[Krzysztof Kozlowski]

On 17.12.2015 23:36, Sergei Shtylyov wrote:
> Hello.
> 
> On 12/17/2015 3:53 AM, Krzysztof Kozlowski wrote:
> 
>>> Maxim Integrated MAX3355E chip integrates a charge pump and
>>> comparators to
>>> enable a system with an integrated USB OTG dual-role transceiver to
>>> function as an USB OTG dual-role device. In addition to
>>> sensing/controlling
>>> Vbus, the chip also passes thru the ID signal from the USB OTG
>>> connector.
>>> On some Renesas boards, this signal is just fed into the SoC thru a GPIO
>>> pin -- there's no real OTG controller, only host and gadget USB
>>> controllers
>>> sharing the same USB bus; however, we'd like to allow host or gadget
>>> drivers to be loaded depending on the cable type, hence the need for the
>>> MAX3355 extcon driver. The Vbus status signals are also wired to GPIOs
>>> (however, we aren't currently interested in them), the OFFVBUS#
>>> signal is
>>> controlled by the host controllers, there's also the SHDN# signal
>>> wired to
>>> a GPIO, it should be driven high for the normal operation.
>>>
>>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>>
>>> ---
>>> Changes in version 3:
>>> - reformatted the change log.
>>>
>>> Changes in version 2:
>>> - added the USB gadget cable support;
>>> - added the remove() driver method which drives SHDN# GPIO low to
>>> save power;
>>> - dropped vendor prefix from the ID GPIO property name;
>>> - changed the GPIO property name suffix to "-gpios";
>>> - switched to usign extcon_set_cable_state_() API;
>>> - switched to using the gpiod/sleeping 'gpiolib' APIs;
>>> - addded error messages to max3355_probe();
>>> - added IRQF_NO_SUSPEND flasg to the devm_request_threaded_irq() call;
>>> - renamed 'ret' variable to 'err' in max3355_probe();
>>> - expanded the Kconfig entry help text;
>>> - added vendor name to the patch summary, the bindings document, the
>>> Kconfig
>>>    entry, the driver heading comment, the module description, and the
>>> change log;
>>> - fixed up and reformatted the change log.
>>>
>>>   Documentation/devicetree/bindings/extcon/extcon-max3355.txt |   21 +
>>>   drivers/extcon/Kconfig                                      |    8
>>>   drivers/extcon/Makefile                                     |    1
>>>   drivers/extcon/extcon-max3355.c                             |  153
>>> ++++++++++++
>>>   4 files changed, 183 insertions(+)
>>>
>>> Index:
>>> renesas/Documentation/devicetree/bindings/extcon/extcon-max3355.txt
>>> ===================================================================
>>> --- /dev/null
>>> +++ renesas/Documentation/devicetree/bindings/extcon/extcon-max3355.txt
>>> @@ -0,0 +1,21 @@
>>> +Maxim Integrated MAX3355 USB OTG chip
>>> +-------------------------------------
>>> +
>>> +MAX3355 integrates a charge pump and comparators to enable a system
>>> with an
>>> +integrated USB OTG dual-role transceiver to function as a USB OTG
>>> dual-role
>>> +device.
>>> +
>>> +Required properties:
>>> +- compatible: should be "maxim,max3355";
>>> +- maxim,shdn-gpios: should contain a phandle and GPIO specifier for
>>> the GPIO pin
>>> +  connected to the MAX3355's SHDN# pin;
>>
>> Could you add some indentation to the wrapped line for this property?
>> For readability.
> 
>    If it's not indented enough, I can add more spaces/tabs.

Ahh, now I see it is sufficient. I need fix my email client.

> 
>>> +- id-gpios: should contain a phandle and GPIO specifier for the GPIO
>>> pin
>>> +  connected to the MAX3355's ID_OUT pin.
>>
>> Ditto.
>>
>> Why this property lacks the vendor prefix i(n comparison to shdn-gpios
>> which has the prefix)?
> 
>    Since the extcon-usb-gpio driver uses "id-gpio" prop already. I can
> add back the vendor prefix if you insist.


It is for USB ID and palmas has it already as well so I do not insist.
Seems generic.

> 
> [...]
>>> Index: renesas/drivers/extcon/extcon-max3355.c
>>> ===================================================================
>>> --- /dev/null
>>> +++ renesas/drivers/extcon/extcon-max3355.c
>>> @@ -0,0 +1,153 @@
> [...]
>>> +static int max3355_probe(struct platform_device *pdev)
>>> +{
>>> +       struct device_node *np = pdev->dev.of_node;
>>> +       struct max3355_data *data;
>>> +       struct gpio_desc *gpiod;
>>> +       int irq, err;
>>> +
>>> +       data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
>>> +                           GFP_KERNEL);
>>> +       if (!data)
>>> +               return -ENOMEM;
>>> +
>>> +       data->edev = devm_extcon_dev_allocate(&pdev->dev,
>>> max3355_cable);
>>> +       if (IS_ERR(data->edev)) {
>>> +               dev_err(&pdev->dev, "failed to allocate extcon
>>> device\n");
>>> +               return PTR_ERR(data->edev);
>>> +       }
>>> +       data->edev->name = kstrdup(np->name, GFP_KERNEL);
>>
>> I think it is not needed any more (extcon_dev_register()) will set it.
>> Anyway there is no checking for NULL return value and no freeing in
>> error/exit paths.
> 
>    Oops, will fix.
> 
> [...]
>>> +static struct platform_driver max3355_driver = {
>>> +       .probe          = max3355_probe,
>>> +       .remove         = max3355_remove,
>>> +       .driver         = {
>>> +               .name   = "extcon-max3355",
>>> +               .of_match_table = max3355_match_table,
>>> +               .owner  = THIS_MODULE,
>>
>> No need for owner.
>> Please pass the source through recent coccicheck and fix the findings.
> 
>    Has it been included in the kernel source somewhere already?

The rules detecting the unnecessary owner should be there for some time
(sice 4.2 or 4.1?). The coccicheck is in kernel - scripts/coccicheck. It
uses coccinelle/spatch. You can run it just like other code-checker
tools - sparse and smatch.

Best regards,
Krzysztof

Re: [PATCH v3] extcon: add Maxim MAX3355 driver

[Chanwoo Choi]

On 2015년 12월 18일 06:20, Sergei Shtylyov wrote:
> Hello.
> 
> On 12/17/2015 05:34 AM, Chanwoo Choi wrote:
> 
>>> On 2015년 12월 17일 03:07, Sergei Shtylyov wrote:
>>>> Maxim Integrated MAX3355E chip integrates a charge pump and comparators to
>>>> enable a system with an integrated USB OTG dual-role transceiver to
>>>> function as an USB OTG dual-role device. In addition to sensing/controlling
>>>> Vbus, the chip also passes thru the ID signal from the USB OTG connector.
>>>> On some Renesas boards, this signal is just fed into the SoC thru a GPIO
>>>> pin -- there's no real OTG controller, only host and gadget USB controllers
>>>> sharing the same USB bus; however, we'd like to allow host or gadget
>>>> drivers to be loaded depending on the cable type, hence the need for the
>>>> MAX3355 extcon driver. The Vbus status signals are also wired to GPIOs
>>>> (however, we aren't currently interested in them), the OFFVBUS# signal is
>>>> controlled by the host controllers, there's also the SHDN# signal wired to
>>>> a GPIO, it should be driven high for the normal operation.
>>>>
>>>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>>>
>>>> ---
>>>> Changes in version 3:
>>>> - reformatted the change log.
>>>>
>>>> Changes in version 2:
>>>> - added the USB gadget cable support;
>>>> - added the remove() driver method which drives SHDN# GPIO low to save power;
>>>> - dropped vendor prefix from the ID GPIO property name;
>>>> - changed the GPIO property name suffix to "-gpios";
>>>> - switched to usign extcon_set_cable_state_() API;
>>>> - switched to using the gpiod/sleeping 'gpiolib' APIs;
>>>> - addded error messages to max3355_probe();
>>>> - added IRQF_NO_SUSPEND flasg to the devm_request_threaded_irq() call;
>>>> - renamed 'ret' variable to 'err' in max3355_probe();
>>>> - expanded the Kconfig entry help text;
>>>> - added vendor name to the patch summary, the bindings document, the Kconfig
>>>>    entry, the driver heading comment, the module description, and the change log;
>>>> - fixed up and reformatted the change log.
>>>>
>>>>   Documentation/devicetree/bindings/extcon/extcon-max3355.txt |   21 +
>>>>   drivers/extcon/Kconfig                                      |    8
>>>>   drivers/extcon/Makefile                                     |    1
>>>>   drivers/extcon/extcon-max3355.c                             |  153 ++++++++++++
>>>>   4 files changed, 183 insertions(+)
>>>>
>>
>> [snip]
>>
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static int max3355_remove(struct platform_device *pdev)
>>>> +{
>>>> +    struct max3355_data *data = platform_get_drvdata(pdev);
>>>> +
>>>> +    gpiod_set_value_cansleep(data->shdn_gpiod, 0);
>>
>> Don't need to handle the 'shdn' gpio on resume/suspend funtcion?
>>
>> But, if the interrput of id gpio is used for wakeup source,
>> there is no reason to handle it for suspend mode.
> 
>    You told me to pass IRQF_NO_SUSPEND to devm_request_threaded_irq(), didn't you?

Yes. You add the this flag on v4 patch. Looks good to me.

Thanks,
Chanwoo Choi

Re: [PATCH v3] extcon: add Maxim MAX3355 driver

[Sergei Shtylyov]

Hello.

On 12/18/2015 3:19 AM, Krzysztof Kozlowski wrote:

[...]

>>> Please pass the source through recent coccicheck and fix the findings.
>>
>>     Has it been included in the kernel source somewhere already?
>
> The rules detecting the unnecessary owner should be there for some time
> (sice 4.2 or 4.1?). The coccicheck is in kernel - scripts/coccicheck. It

    Found it already.

> uses coccinelle/spatch.

    Installed it.

> You can run it just like other code-checker
> tools - sparse and smatch.

    I tried but couldn't figure out how to confine 'make coccicheck'only to 
the files I need.

> Best regards,
> Krzysztof

MBR, Sergei