diff options
| -rw-r--r-- | drivers/usb/otg/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/usb/otg/Makefile | 5 | ||||
| -rw-r--r-- | drivers/usb/otg/gpio_vbus.c | 335 | ||||
| -rw-r--r-- | include/linux/usb/gpio_vbus.h | 30 |
4 files changed, 383 insertions, 0 deletions
diff --git a/drivers/usb/otg/Kconfig b/drivers/usb/otg/Kconfig index 860342902bbb..afe91bfea7f2 100644 --- a/drivers/usb/otg/Kconfig +++ b/drivers/usb/otg/Kconfig @@ -14,6 +14,19 @@ config USB_OTG_UTILS Select this to make sure the build includes objects from the OTG infrastructure directory. +# +# USB Transceiver Drivers +# +config USB_GPIO_VBUS + tristate "GPIO based peripheral-only VBUS sensing 'transceiver'" + depends on GENERIC_GPIO + select USB_OTG_UTILS + help + Provides simple GPIO VBUS sensing for controllers with an + internal transceiver via the otg_transceiver interface, and + optionally control of a D+ pullup GPIO as well as a VBUS + current limit regulator. + config ISP1301_OMAP tristate "Philips ISP1301 with OMAP OTG" depends on I2C && ARCH_OMAP_OTG diff --git a/drivers/usb/otg/Makefile b/drivers/usb/otg/Makefile index 483816685d00..6c58b36ca7cf 100644 --- a/drivers/usb/otg/Makefile +++ b/drivers/usb/otg/Makefile @@ -1,3 +1,8 @@ +# +# OTG infrastructure and transceiver drivers +# + +obj-$(CONFIG_USB_GPIO_VBUS) += gpio_vbus.o obj-$(CONFIG_ISP1301_OMAP) += isp1301_omap.o ifeq ($(CONFIG_USB_DEBUG),y) diff --git a/drivers/usb/otg/gpio_vbus.c b/drivers/usb/otg/gpio_vbus.c new file mode 100644 index 000000000000..63a6036f04be --- /dev/null +++ b/drivers/usb/otg/gpio_vbus.c @@ -0,0 +1,335 @@ +/* + * gpio-vbus.c - simple GPIO VBUS sensing driver for B peripheral devices + * + * Copyright (c) 2008 Philipp Zabel <philipp.zabel@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> +#include <linux/interrupt.h> +#include <linux/usb.h> + +#include <linux/regulator/consumer.h> + +#include <linux/usb/gadget.h> +#include <linux/usb/gpio_vbus.h> +#include <linux/usb/otg.h> + + +/* + * A simple GPIO VBUS sensing driver for B peripheral only devices + * with internal transceivers. It can control a D+ pullup GPIO and + * a regulator to limit the current drawn from VBUS. + * + * Needs to be loaded before the UDC driver that will use it. + */ +struct gpio_vbus_data { + struct otg_transceiver otg; + struct device *dev; + struct regulator *vbus_draw; + int vbus_draw_enabled; + unsigned mA; +}; + + +/* + * This driver relies on "both edges" triggering. VBUS has 100 msec to + * stabilize, so the peripheral controller driver may need to cope with + * some bouncing due to current surges (e.g. charging local capacitance) + * and contact chatter. + * + * REVISIT in desperate straits, toggling between rising and falling + * edges might be workable. + */ +#define VBUS_IRQ_FLAGS \ + ( IRQF_SAMPLE_RANDOM | IRQF_SHARED \ + | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING ) + + +/* interface to regulator framework */ +static void set_vbus_draw(struct gpio_vbus_data *gpio_vbus, unsigned mA) +{ + struct regulator *vbus_draw = gpio_vbus->vbus_draw; + int enabled; + + if (!vbus_draw) + return; + + enabled = gpio_vbus->vbus_draw_enabled; + if (mA) { + regulator_set_current_limit(vbus_draw, 0, 1000 * mA); + if (!enabled) { + regulator_enable(vbus_draw); + gpio_vbus->vbus_draw_enabled = 1; + } + } else { + if (enabled) { + regulator_disable(vbus_draw); + gpio_vbus->vbus_draw_enabled = 0; + } + } + gpio_vbus->mA = mA; +} + +/* VBUS change IRQ handler */ +static irqreturn_t gpio_vbus_irq(int irq, void *data) +{ + struct platform_device *pdev = data; + struct gpio_vbus_mach_info *pdata = pdev->dev.platform_data; + struct gpio_vbus_data *gpio_vbus = platform_get_drvdata(pdev); + int gpio, vbus; + + vbus = gpio_get_value(pdata->gpio_vbus); + if (pdata->gpio_vbus_inverted) + vbus = !vbus; + + dev_dbg(&pdev->dev, "VBUS %s (gadget: %s)\n", + vbus ? "supplied" : "inactive", + gpio_vbus->otg.gadget ? gpio_vbus->otg.gadget->name : "none"); + + if (!gpio_vbus->otg.gadget) + return IRQ_HANDLED; + + /* Peripheral controllers which manage the pullup themselves won't have + * gpio_pullup configured here. If it's configured here, we'll do what + * isp1301_omap::b_peripheral() does and enable the pullup here... although + * that may complicate usb_gadget_{,dis}connect() support. + */ + gpio = pdata->gpio_pullup; + if (vbus) { + gpio_vbus->otg.state = OTG_STATE_B_PERIPHERAL; + usb_gadget_vbus_connect(gpio_vbus->otg.gadget); + + /* drawing a "unit load" is *always* OK, except for OTG */ + set_vbus_draw(gpio_vbus, 100); + + /* optionally enable D+ pullup */ + if (gpio_is_valid(gpio)) + gpio_set_value(gpio, !pdata->gpio_pullup_inverted); + } else { + /* optionally disable D+ pullup */ + if (gpio_is_valid(gpio)) + gpio_set_value(gpio, pdata->gpio_pullup_inverted); + + set_vbus_draw(gpio_vbus, 0); + + usb_gadget_vbus_disconnect(gpio_vbus->otg.gadget); + gpio_vbus->otg.state = OTG_STATE_B_IDLE; + } + + return IRQ_HANDLED; +} + +/* OTG transceiver interface */ + +/* bind/unbind the peripheral controller */ +static int gpio_vbus_set_peripheral(struct otg_transceiver *otg, + struct usb_gadget *gadget) +{ + struct gpio_vbus_data *gpio_vbus; + struct gpio_vbus_mach_info *pdata; + struct platform_device *pdev; + int gpio, irq; + + gpio_vbus = container_of(otg, struct gpio_vbus_data, otg); + pdev = to_platform_device(gpio_vbus->dev); + pdata = gpio_vbus->dev->platform_data; + irq = gpio_to_irq(pdata->gpio_vbus); + gpio = pdata->gpio_pullup; + + if (!gadget) { + dev_dbg(&pdev->dev, "unregistering gadget '%s'\n", + otg->gadget->name); + + /* optionally disable D+ pullup */ + if (gpio_is_valid(gpio)) + gpio_set_value(gpio, pdata->gpio_pullup_inverted); + + set_vbus_draw(gpio_vbus, 0); + + usb_gadget_vbus_disconnect(otg->gadget); + otg->state = OTG_STATE_UNDEFINED; + + otg->gadget = NULL; + return 0; + } + + otg->gadget = gadget; + dev_dbg(&pdev->dev, "registered gadget '%s'\n", gadget->name); + + /* initialize connection state */ + gpio_vbus_irq(irq, pdev); + return 0; +} + +/* effective for B devices, ignored for A-peripheral */ +static int gpio_vbus_set_power(struct otg_transceiver *otg, unsigned mA) +{ + struct gpio_vbus_data *gpio_vbus; + + gpio_vbus = container_of(otg, struct gpio_vbus_data, otg); + + if (otg->state == OTG_STATE_B_PERIPHERAL) + set_vbus_draw(gpio_vbus, mA); + return 0; +} + +/* for non-OTG B devices: set/clear transceiver suspend mode */ +static int gpio_vbus_set_suspend(struct otg_transceiver *otg, int suspend) +{ + struct gpio_vbus_data *gpio_vbus; + + gpio_vbus = container_of(otg, struct gpio_vbus_data, otg); + + /* draw max 0 mA from vbus in suspend mode; or the previously + * recorded amount of current if not suspended + * + * NOTE: high powered configs (mA > 100) may draw up to 2.5 mA + * if they're wake-enabled ... we don't handle that yet. + */ + return gpio_vbus_set_power(otg, suspend ? 0 : gpio_vbus->mA); +} + +/* platform driver interface */ + +static int __init gpio_vbus_probe(struct platform_device *pdev) +{ + struct gpio_vbus_mach_info *pdata = pdev->dev.platform_data; + struct gpio_vbus_data *gpio_vbus; + struct resource *res; + int err, gpio, irq; + + if (!pdata || !gpio_is_valid(pdata->gpio_vbus)) + return -EINVAL; + gpio = pdata->gpio_vbus; + + gpio_vbus = kzalloc(sizeof(struct gpio_vbus_data), GFP_KERNEL); + if (!gpio_vbus) + return -ENOMEM; + + platform_set_drvdata(pdev, gpio_vbus); + gpio_vbus->dev = &pdev->dev; + gpio_vbus->otg.label = "gpio-vbus"; + gpio_vbus->otg.state = OTG_STATE_UNDEFINED; + gpio_vbus->otg.set_peripheral = gpio_vbus_set_peripheral; + gpio_vbus->otg.set_power = gpio_vbus_set_power; + gpio_vbus->otg.set_suspend = gpio_vbus_set_suspend; + + err = gpio_request(gpio, "vbus_detect"); + if (err) { + dev_err(&pdev->dev, "can't request vbus gpio %d, err: %d\n", + gpio, err); + goto err_gpio; + } + gpio_direction_input(gpio); + + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (res) { + irq = res->start; + res->flags &= IRQF_TRIGGER_MASK; + res->flags |= IRQF_SAMPLE_RANDOM | IRQF_SHARED; + } else + irq = gpio_to_irq(gpio); + + /* if data line pullup is in use, initialize it to "not pulling up" */ + gpio = pdata->gpio_pullup; + if (gpio_is_valid(gpio)) { + err = gpio_request(gpio, "udc_pullup"); + if (err) { + dev_err(&pdev->dev, + "can't request pullup gpio %d, err: %d\n", + gpio, err); + gpio_free(pdata->gpio_vbus); + goto err_gpio; + } + gpio_direction_output(gpio, pdata->gpio_pullup_inverted); + } + + err = request_irq(irq, gpio_vbus_irq, VBUS_IRQ_FLAGS, + "vbus_detect", pdev); + if (err) { + dev_err(&pdev->dev, "can't request irq %i, err: %d\n", + irq, err); + goto err_irq; + } + + /* only active when a gadget is registered */ + err = otg_set_transceiver(&gpio_vbus->otg); + if (err) { + dev_err(&pdev->dev, "can't register transceiver, err: %d\n", + err); + goto err_otg; + } + + gpio_vbus->vbus_draw = regulator_get(&pdev->dev, "vbus_draw"); + if (IS_ERR(gpio_vbus->vbus_draw)) { + dev_dbg(&pdev->dev, "can't get vbus_draw regulator, err: %ld\n", + PTR_ERR(gpio_vbus->vbus_draw)); + gpio_vbus->vbus_draw = NULL; + } + + return 0; +err_otg: + free_irq(irq, &pdev->dev); +err_irq: + if (gpio_is_valid(pdata->gpio_pullup)) + gpio_free(pdata->gpio_pullup); + gpio_free(pdata->gpio_vbus); +err_gpio: + platform_set_drvdata(pdev, NULL); + kfree(gpio_vbus); + return err; +} + +static int __exit gpio_vbus_remove(struct platform_device *pdev) +{ + struct gpio_vbus_data *gpio_vbus = platform_get_drvdata(pdev); + struct gpio_vbus_mach_info *pdata = pdev->dev.platform_data; + int gpio = pdata->gpio_vbus; + + regulator_put(gpio_vbus->vbus_draw); + + otg_set_transceiver(NULL); + + free_irq(gpio_to_irq(gpio), &pdev->dev); + if (gpio_is_valid(pdata->gpio_pullup)) + gpio_free(pdata->gpio_pullup); + gpio_free(gpio); + platform_set_drvdata(pdev, NULL); + kfree(gpio_vbus); + + return 0; +} + +/* NOTE: the gpio-vbus device may *NOT* be hotplugged */ + +MODULE_ALIAS("platform:gpio-vbus"); + +static struct platform_driver gpio_vbus_driver = { + .driver = { + .name = "gpio-vbus", + .owner = THIS_MODULE, + }, + .remove = __exit_p(gpio_vbus_remove), +}; + +static int __init gpio_vbus_init(void) +{ + return platform_driver_probe(&gpio_vbus_driver, gpio_vbus_probe); +} +module_init(gpio_vbus_init); + +static void __exit gpio_vbus_exit(void) +{ + platform_driver_unregister(&gpio_vbus_driver); +} +module_exit(gpio_vbus_exit); + +MODULE_DESCRIPTION("simple GPIO controlled OTG transceiver driver"); +MODULE_AUTHOR("Philipp Zabel"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/usb/gpio_vbus.h b/include/linux/usb/gpio_vbus.h new file mode 100644 index 000000000000..d9f03ccc2d60 --- /dev/null +++ b/include/linux/usb/gpio_vbus.h @@ -0,0 +1,30 @@ +/* + * A simple GPIO VBUS sensing driver for B peripheral only devices + * with internal transceivers. + * Optionally D+ pullup can be controlled by a second GPIO. + * + * Copyright (c) 2008 Philipp Zabel <philipp.zabel@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +/** + * struct gpio_vbus_mach_info - configuration for gpio_vbus + * @gpio_vbus: VBUS sensing GPIO + * @gpio_pullup: optional D+ or D- pullup GPIO (else negative/invalid) + * @gpio_vbus_inverted: true if gpio_vbus is active low + * @gpio_pullup_inverted: true if gpio_pullup is active low + * + * The VBUS sensing GPIO should have a pulldown, which will normally be + * part of a resistor ladder turning a 4.0V-5.25V level on VBUS into a + * value the GPIO detects as active. Some systems will use comparators. + */ +struct gpio_vbus_mach_info { + int gpio_vbus; + int gpio_pullup; + bool gpio_vbus_inverted; + bool gpio_pullup_inverted; +}; |