On the db410c 96boards platform we have a TC7USB40MU[1] on the board to mux the D+/D- lines from the SoC between a micro usb "device" port and a USB hub for "host" roles. Upon a role switch, we need to change this mux to forward the D+/D- lines to either the port or the hub. Introduce a driver for this device that hooks into the generic mux framework logically asserts a gpio to mux the D+/D- lines to the 2D+/2D- output when the state is set to "1". Similary, deassert the gpio and mux the D+/D- lines to the 1D+/1D- output when the state is set to "0". [1] https://toshiba.semicon-storage.com/ap-en/product/logic/bus-switch/detail.TC7USB40MU.html Cc: Peter Rosin <peda@xxxxxxxxxx> Cc: Peter Chen <peter.chen@xxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: <devicetree@xxxxxxxxxxxxxxx> Signed-off-by: Stephen Boyd <stephen.boyd@xxxxxxxxxx> --- We may be able to ignore this patch and just use mux-gpio.c file. I'll investigate that approach but I'd like to keep the compatible string in case we need to do something later. .../devicetree/bindings/usb/toshiba,tc7usb40mu.txt | 31 +++++++++ drivers/usb/misc/Kconfig | 11 ++++ drivers/usb/misc/Makefile | 1 + drivers/usb/misc/tc7usb40mu.c | 74 ++++++++++++++++++++++ 4 files changed, 117 insertions(+) create mode 100644 Documentation/devicetree/bindings/usb/toshiba,tc7usb40mu.txt create mode 100644 drivers/usb/misc/tc7usb40mu.c diff --git a/Documentation/devicetree/bindings/usb/toshiba,tc7usb40mu.txt b/Documentation/devicetree/bindings/usb/toshiba,tc7usb40mu.txt new file mode 100644 index 000000000000..5c6b2b39825f --- /dev/null +++ b/Documentation/devicetree/bindings/usb/toshiba,tc7usb40mu.txt @@ -0,0 +1,31 @@ +Toshiba TC7USB40MU + +This device muxes USB D+/D- lines between two outputs called 1D+/1D- and +2D+/2D-. When the switch pin is asserted, the device muxes out 2D+/2D-, and +when it's deasserted it muxes out 1D+/1D-. + +This can be used to mux USB D+/D- lines between a USB hub and a micro-USB port +to provide host mode and device modes with the same USB controller. + +PROPERTIES + +- compatible: + Usage: required + Value type: <string> + Definition: Should contain "toshiba,tc7usb40mu" + +- mux-gpios: + Usage: required + Value type: <prop-encoded-array> + Definition: Should contain the gpio used to toggle the switch. Logically + asserting the gpio will cause the device to mux the 2D+/2D- + lines and deasserting the gpio will cause the device to mux + the 1D+/1D- lines. + +Example: + + usb-switch { + compatible = "toshiba,tc7usb40mu"; + mux-gpios = <&gpio 10 GPIO_ACTIVE_HIGH>; + #mux-control-cells = <0>; + }; diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig index 0f9f25db9163..df44c9d16eb1 100644 --- a/drivers/usb/misc/Kconfig +++ b/drivers/usb/misc/Kconfig @@ -46,6 +46,17 @@ config USB_SEVSEG To compile this driver as a module, choose M here: the module will be called usbsevseg. +config USB_TC7USB40MU + tristate "TC7USB40MU USB mux support" + depends on (GPIOLIB && MULTIPLEXER) || COMPILE_TEST + help + Say Y here if you have a TC7USB40MU by Toshiba. A USB controller + driver can then use the mux controller provided by this driver to + route the D+/D- lines to two different devices downstream. For + example, one downstream device could be a micro-USB port, and the + other could be a USB hub, allowing a device to provide either + device or host mode via a single USB controller. + config USB_RIO500 tristate "USB Diamond Rio500 support" help diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile index 7fdb45fc976f..42268fcb8a60 100644 --- a/drivers/usb/misc/Makefile +++ b/drivers/usb/misc/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_USB_LEGOTOWER) += legousbtower.o obj-$(CONFIG_USB_RIO500) += rio500.o obj-$(CONFIG_USB_TEST) += usbtest.o obj-$(CONFIG_USB_EHSET_TEST_FIXTURE) += ehset.o +obj-$(CONFIG_USB_TC7USB40MU) += tc7usb40mu.o obj-$(CONFIG_USB_TRANCEVIBRATOR) += trancevibrator.o obj-$(CONFIG_USB_USS720) += uss720.o obj-$(CONFIG_USB_SEVSEG) += usbsevseg.o diff --git a/drivers/usb/misc/tc7usb40mu.c b/drivers/usb/misc/tc7usb40mu.c new file mode 100644 index 000000000000..fbccd2fc0030 --- /dev/null +++ b/drivers/usb/misc/tc7usb40mu.c @@ -0,0 +1,74 @@ +/** + * Copyright (C) 2016-2017 Linaro Ltd. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/platform_device.h> +#include <linux/module.h> +#include <linux/gpio/consumer.h> +#include <linux/mux/driver.h> + +struct tc7usb40mu_drv { + struct gpio_desc *gpio; +}; + +static int tc7usb40mu_mux_set(struct mux_control *mux, int state) +{ + struct tc7usb40mu_drv *drv = mux_chip_priv(mux->chip); + + gpiod_set_value_cansleep(drv->gpio, state); + + return 0; +} + +static const struct mux_control_ops tc7usb40mu_mux_ops = { + .set = tc7usb40mu_mux_set, +}; + +static int tc7usb40mu_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct tc7usb40mu_drv *drv; + struct mux_chip *mux_chip; + + mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*drv)); + if (!mux_chip) + return -ENOMEM; + + mux_chip->ops = &tc7usb40mu_mux_ops; + mux_chip->mux->states = 2; /* 1D+/1D- and 2D+/2D- */ + + drv = mux_chip_priv(mux_chip); + drv->gpio = devm_gpiod_get(dev, "mux", GPIOD_ASIS); + if (IS_ERR(drv->gpio)) + return PTR_ERR(drv->gpio); + + return devm_mux_chip_register(dev, mux_chip); +} + +static const struct of_device_id tc7usb40mu_dt_match[] = { + { .compatible = "toshiba,tc7usb40mu", }, + { } +}; +MODULE_DEVICE_TABLE(of, tc7usb40mu_dt_match); + +static struct platform_driver tc7usb40mu_driver = { + .probe = tc7usb40mu_probe, + .driver = { + .name = "tc7usb40mu", + .of_match_table = tc7usb40mu_dt_match, + }, +}; +module_platform_driver(tc7usb40mu_driver); + +MODULE_AUTHOR("Stephen Boyd <stephen.boyd@xxxxxxxxxx>"); +MODULE_DESCRIPTION("TC7USB40MU USB multiplexer driver"); +MODULE_LICENSE("GPL"); -- 2.10.0.297.gf6727b0 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
