On Mon, Nov 22, 2021 at 11:58:34AM +0530, Piyush Mehta wrote: > Microchip's USB224x family of Hi-Speed USB 2.0 flash media card controllers > provides an ultra-fast interface between a USB host controller and flash > media cards. > > This patch adds a GPIO based usb-sd reset for USB2244 USB2 ultra fast > SD controller. This usb2244 driver trigger sd reset signal after soft > reset or core Reset. The SD needs to be resetted after completion of > phy initialization. After the toggling of gpio, controller gets out > form reset. USB2244 is a simple platform device driver. > > As part of the reset, sets the direction of the pin to output before > toggling the pin. Delay of microseconds is added in between high and > low to meet the setup and hold time requirement of the reset. > > Signed-off-by: Piyush Mehta <piyush.mehta@xxxxxxxxxx> > --- > Changes for V2: > - Update reset polarity, make reset ACTIVE LOW in the usb2244 driver. > - Fix WARNING: msleep < 20ms can sleep for up to 20ms by changing msleep to > usleep_range() > --- > drivers/usb/misc/Kconfig | 10 +++++++ > drivers/usb/misc/Makefile | 1 + > drivers/usb/misc/usb2244.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++ This isn't really a USB driver, so maybe drivers/misc/ instead? > 3 files changed, 80 insertions(+) > create mode 100644 drivers/usb/misc/usb2244.c > > diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig > index 8f11443..e1c66a2 100644 > --- a/drivers/usb/misc/Kconfig > +++ b/drivers/usb/misc/Kconfig > @@ -215,6 +215,16 @@ config USB_ISIGHTFW > driver beforehand. Tools for doing so are available at > http://bersace03.free.fr > > +config USB_USB2244 > + tristate "Microchip USB2244 Ultra Fast USB 2.0 SD driver" > + depends on GPIOLIB > + help > + Say Y or M here if you want to reset Microchip USB2244 Ultra Fast > + USB 2.0 SD controller. > + This option enables support for Microchip USB2244 Ultra Fast USB 2.0 > + SD controller. This driver reset the gpio pin makes controller out of > + reset. Module name? > + > config USB_YUREX > tristate "USB YUREX driver support" > help > diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile > index 5f4e598..5b4af7d 100644 > --- a/drivers/usb/misc/Makefile > +++ b/drivers/usb/misc/Makefile > @@ -21,6 +21,7 @@ obj-$(CONFIG_USB_LEGOTOWER) += legousbtower.o > obj-$(CONFIG_USB_TEST) += usbtest.o > obj-$(CONFIG_USB_EHSET_TEST_FIXTURE) += ehset.o > obj-$(CONFIG_USB_TRANCEVIBRATOR) += trancevibrator.o > +obj-$(CONFIG_USB_USB2244) += usb2244.o > obj-$(CONFIG_USB_USS720) += uss720.o > obj-$(CONFIG_USB_SEVSEG) += usbsevseg.o > obj-$(CONFIG_USB_YUREX) += yurex.o > diff --git a/drivers/usb/misc/usb2244.c b/drivers/usb/misc/usb2244.c > new file mode 100644 > index 0000000..5a868c2 > --- /dev/null > +++ b/drivers/usb/misc/usb2244.c > @@ -0,0 +1,69 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Driver for the Microchip USB2244 Ultra Fast USB 2.0 Multi-Format, > + * SD/MMC, and MS Flash Media Controllers > + * > + * Copyright (c) 2021 Xilinx, Inc. > + */ > + > +#include <linux/delay.h> > +#include <linux/err.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of_platform.h> > +#include <linux/gpio/consumer.h> > +#include <linux/platform_device.h> > + > +struct usb2244 { > + struct gpio_desc *reset_gpio; > +}; Why is this structure needed? > + > +static int usb2244_init_hw(struct device *dev, struct usb2244 *data) > +{ > + data = devm_kzalloc(dev, sizeof(struct usb2244), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); > + if (IS_ERR(data->reset_gpio)) { > + dev_err_probe(dev, PTR_ERR(data->reset_gpio), > + "Failed to request reset GPIO %ld, errcode", > + PTR_ERR(data->reset_gpio)); > + return PTR_ERR(data->reset_gpio); > + } > + > + /* Toggle RESET_N to reset the hub. */ > + gpiod_set_value_cansleep(data->reset_gpio, 1); > + usleep_range(5, 10); > + gpiod_set_value_cansleep(data->reset_gpio, 0); > + usleep_range(5000, 6000); Why do you need a kernel driver for this at all? Why not just toggle the pin from userspace? thanks, greg k-h
