Hi Sergei, I reviewed this patch quickly. This driver has just two gpio without any registers for IP. I wonder whether MAX3355E is separate chip to detect external connector or just use gpio of AP. Could you send the datasheet of MAX3355E to me? Thanks, Chanwoo Choi On 12/11/2014 08:28 AM, Sergei Shtylyov wrote: > MAX3355E chip 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. 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're not currently intested in them), the OFFVBUS# signal > is controlled by the host controllers, there's also the SHDN# signal wired to > GPIO, which should be high for normal operation. > > Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx> > > --- > The patch is against the 'extcon-next' branch of the 'extcon.git' repo. > > Documentation/devicetree/bindings/extcon/extcon-max3355.txt | 21 ++ > drivers/extcon/Kconfig | 6 > drivers/extcon/Makefile | 1 > drivers/extcon/extcon-max3355.c | 122 ++++++++++++ > 4 files changed, 150 insertions(+) > > Index: extcon/Documentation/devicetree/bindings/extcon/extcon-max3355.txt > =================================================================== > --- /dev/null > +++ extcon/Documentation/devicetree/bindings/extcon/extcon-max3355.txt > @@ -0,0 +1,21 @@ > +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-gpio: should contain a phandle and GPIO specifier for the GPIO pin > + connected to the MAX3355's SHDN# pin; > +- maxim,id-gpio: 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-gpio = <&gpio2 4 GPIO_ACTIVE_LOW>; > + maxim,id-gpio = <&gpio5 31 GPIO_ACTIVE_HIGH>; > + }; > Index: extcon/drivers/extcon/Kconfig > =================================================================== > --- extcon.orig/drivers/extcon/Kconfig > +++ extcon/drivers/extcon/Kconfig > @@ -45,6 +45,12 @@ config EXTCON_MAX14577 > Maxim MAX14577/77836. The MAX14577/77836 MUIC is a USB port accessory > detector and switch. > > +config EXTCON_MAX3355 > + tristate "MAX3355 USB OTG EXTCON Support" > + help > + Say Y here to enable support for the USB host detection by MAX3355 > + OTG USB chip. > + > config EXTCON_MAX77693 > tristate "MAX77693 EXTCON Support" > depends on MFD_MAX77693 && INPUT > Index: extcon/drivers/extcon/Makefile > =================================================================== > --- extcon.orig/drivers/extcon/Makefile > +++ extcon/drivers/extcon/Makefile > @@ -7,6 +7,7 @@ obj-$(CONFIG_EXTCON_ADC_JACK) += extcon- > obj-$(CONFIG_EXTCON_ARIZONA) += extcon-arizona.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-$(CONFIG_EXTCON_MAX8997) += extcon-max8997.o > obj-$(CONFIG_EXTCON_PALMAS) += extcon-palmas.o > Index: extcon/drivers/extcon/extcon-max3355.c > =================================================================== > --- /dev/null > +++ extcon/drivers/extcon/extcon-max3355.c > @@ -0,0 +1,122 @@ > +/* > + * MAX3355 USB OTG chip extcon driver > + * > + * Copyright (C) 2014 Cogent Embedded, Inc. > + * Author: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx> > + * > + * 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; > + int id_gpio; > +}; > + > +static const char *max3355_cable[] = { > + [0] = "USB-HOST", > + NULL, > +}; > + > +static irqreturn_t max3355_id_irq(int irq, void *dev_id) > +{ > + struct max3355_data *data = dev_id; > + int id = gpio_get_value(data->id_gpio); > + > + extcon_set_cable_state(data->edev, "USB-HOST", !id); > + > + return IRQ_HANDLED; > +} > + > +static int max3355_probe(struct platform_device *pdev) > +{ > + struct device_node *np = pdev->dev.of_node; > + struct max3355_data *data; > + int gpio, irq, ret; > + > + 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); > + > + gpio = of_get_named_gpio(np, "maxim,id-gpio", 0); > + if (gpio < 0) > + return gpio; > + data->id_gpio = gpio; > + > + gpio = of_get_named_gpio(np, "maxim,shdn-gpio", 0); > + if (gpio < 0) > + return gpio; > + > + ret = devm_gpio_request_one(&pdev->dev, gpio, GPIOF_DIR_OUT | > + GPIOF_INIT_HIGH, pdev->name); > + if (ret < 0) > + return ret; > + > + ret = devm_gpio_request_one(&pdev->dev, data->id_gpio, GPIOF_DIR_IN, > + pdev->name); > + if (ret < 0) > + return ret; > + > + ret = devm_extcon_dev_register(&pdev->dev, data->edev); > + if (ret < 0) > + return ret; > + > + irq = gpio_to_irq(data->id_gpio); > + if (irq < 0) > + return irq; > + > + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq, > + IRQF_TRIGGER_RISING | > + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, > + pdev->name, data); > + if (ret < 0) > + return ret; > + > + platform_set_drvdata(pdev, data); > + > + /* Perform initial detection */ > + max3355_id_irq(irq, data); > + > + 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, > + .driver = { > + .name = "extcon-max3355", > + .of_match_table = max3355_match_table, > + .owner = THIS_MODULE, > + }, > +}; > + > +module_platform_driver(max3355_driver); > + > +MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("MAX3355 extcon driver"); > +MODULE_LICENSE("GPL v2"); > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html