On 7 December 2015 at 18:37, Peter Chen <peter.chen@xxxxxxxxxxxxx> wrote: > Current USB HUB driver lacks of platform interfaces to configure > external signal on HUB chip, eg, the PHY input clock and gpio reset > pin for HUB, these kinds of HUBs are usually soldered at the board, > and they are not hot-plug USB devices. > > With this patch, the user can configure the HUB's pins at platform > part (through dts or platform), and these configuration will be > effective before the USB bus can be used, we use subsys_initcall > for this driver. > > Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> > --- > MAINTAINERS | 7 ++ > drivers/usb/misc/Kconfig | 9 ++ > drivers/usb/misc/Makefile | 1 + > drivers/usb/misc/generic_onboard_hub.c | 162 ++++++++++++++++++++++++++++++++ > include/linux/usb/generic_onboard_hub.h | 11 +++ > 5 files changed, 190 insertions(+) > create mode 100644 drivers/usb/misc/generic_onboard_hub.c > create mode 100644 include/linux/usb/generic_onboard_hub.h > > diff --git a/MAINTAINERS b/MAINTAINERS > index e9caa4b..cc1981e 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11121,6 +11121,13 @@ S: Maintained > F: Documentation/usb/ohci.txt > F: drivers/usb/host/ohci* > > +USB Generic Onboard HUB Driver > +M: Peter Chen <Peter.Chen@xxxxxxxxxxxxx> > +T: git git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb.git > +L: linux-usb@xxxxxxxxxxxxxxx > +S: Maintained > +F: drivers/usb/misc/generic_onboard_hub.c > + > USB OTG FSM (Finite State Machine) > M: Peter Chen <Peter.Chen@xxxxxxxxxxxxx> > T: git git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb.git > diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig > index f7a7fc2..8921cae 100644 > --- a/drivers/usb/misc/Kconfig > +++ b/drivers/usb/misc/Kconfig > @@ -268,3 +268,12 @@ config USB_CHAOSKEY > > To compile this driver as a module, choose M here: the > module will be called chaoskey. > + > +config USB_ONBOARD_HUB > + tristate "Generic USB Onboard HUB" > + help > + Say Y here if your board has an onboard HUB, and this hub needs > + to control its PHY clock and reset pin through external signals. > + If you are not sure, say N. > + > + To compile this driver as a module, choose M here. > diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile > index 45fd4ac..da52e9a 100644 > --- a/drivers/usb/misc/Makefile > +++ b/drivers/usb/misc/Makefile > @@ -29,3 +29,4 @@ obj-$(CONFIG_USB_CHAOSKEY) += chaoskey.o > > obj-$(CONFIG_USB_SISUSBVGA) += sisusbvga/ > obj-$(CONFIG_USB_LINK_LAYER_TEST) += lvstest.o > +obj-$(CONFIG_USB_ONBOARD_HUB) += generic_onboard_hub.o > diff --git a/drivers/usb/misc/generic_onboard_hub.c b/drivers/usb/misc/generic_onboard_hub.c > new file mode 100644 > index 0000000..df722a0 > --- /dev/null > +++ b/drivers/usb/misc/generic_onboard_hub.c > @@ -0,0 +1,162 @@ > +/* > + * usb_hub_generic.c The generic onboard USB HUB driver > + * > + * Copyright (C) 2015 Freescale Semiconductor, Inc. > + * Author: Peter Chen <peter.chen@xxxxxxxxxxxxx> > + * > + * This program is free software: you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 of > + * the License 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. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +/* > + * This driver is only for the USB HUB devices which need to control > + * their external pins(clock, reset, etc), and these USB HUB devices > + * are soldered at the board. > + */ > + > +#define DEBUG > +#include <linux/clk.h> > +#include <linux/delay.h> > +#include <linux/gpio.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_gpio.h> > +#include <linux/platform_device.h> > +#include <linux/regulator/consumer.h> > +#include <linux/slab.h> > +#include <linux/usb/generic_onboard_hub.h> > + > +struct usb_hub_generic_data { > + struct clk *clk; > +}; > + > +static int usb_hub_generic_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct usb_hub_generic_platform_data *pdata = dev->platform_data; > + struct usb_hub_generic_data *hub_data; > + int reset_pol = 0, duration_us = 50, ret = 0; > + struct gpio_desc *gpiod_reset = NULL; > + > + hub_data = devm_kzalloc(dev, sizeof(*hub_data), GFP_KERNEL); > + if (!hub_data) > + return -ENOMEM; > + > + if (dev->of_node) { > + struct device_node *node = dev->of_node; > + > + hub_data->clk = devm_clk_get(dev, "external_clk"); > + if (IS_ERR(hub_data->clk)) { > + dev_dbg(dev, "Can't get external clock: %ld\n", > + PTR_ERR(hub_data->clk)); > + } Is the intended behaviour to keep going here event when there is an error? Can the "hub_data" really work without a clock? > + > + /* > + * Try to get the information for HUB reset, the > + * default setting like below: > + * > + * - Reset state is low > + * - The duration is 50us > + */ > + if (of_find_property(node, "hub-reset-active-high", NULL)) > + reset_pol = 1; > + > + of_property_read_u32(node, "hub-reset-duration-us", > + &duration_us); > + > + gpiod_reset = devm_gpiod_get_optional(dev, "hub-reset", > + reset_pol ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW); > + ret = PTR_ERR_OR_ZERO(gpiod_reset); > + if (ret) { > + dev_err(dev, "Failed to get reset gpio, err = %d\n", > + ret); > + return ret; > + } > + } else if (pdata) { > + hub_data->clk = pdata->ext_clk; > + duration_us = pdata->gpio_reset_duration_us; > + reset_pol = pdata->gpio_reset_polarity; > + > + if (gpio_is_valid(pdata->gpio_reset)) { > + ret = devm_gpio_request_one( > + dev, pdata->gpio_reset, reset_pol > + ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, > + dev_name(dev)); > + if (!ret) > + gpiod_reset = gpio_to_desc(pdata->gpio_reset); > + } > + } > + > + if (!IS_ERR(hub_data->clk)) { > + ret = clk_prepare_enable(hub_data->clk); > + if (ret) { > + dev_err(dev, > + "Can't enable external clock: %d\n", > + ret); > + return ret; > + } > + } > + > + if (gpiod_reset) { > + /* Sanity check */ > + if (duration_us > 1000000) > + duration_us = 50; > + usleep_range(duration_us, duration_us + 100); > + gpiod_set_value(gpiod_reset, reset_pol ? 0 : 1); What are these hard-coded values? Shouldn't this be taken from the DT? If not then some comments explaining the values would be appreciated. > + } > + > + dev_set_drvdata(dev, hub_data); > + return ret; > +} > + > +static int usb_hub_generic_remove(struct platform_device *pdev) > +{ > + struct usb_hub_generic_data *hub_data = platform_get_drvdata(pdev); > + > + if (!IS_ERR(hub_data->clk)) > + clk_disable_unprepare(hub_data->clk); > + > + return 0; > +} > + > +#ifdef CONFIG_OF > +static const struct of_device_id usb_hub_generic_dt_ids[] = { > + {.compatible = "generic-onboard-hub"}, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, usb_hub_generic_dt_ids); > +#endif > + > +static struct platform_driver usb_hub_generic_driver = { > + .probe = usb_hub_generic_probe, > + .remove = usb_hub_generic_remove, > + .driver = { > + .name = "usb_hub_generic_onboard", > + .of_match_table = usb_hub_generic_dt_ids, > + }, > +}; > + > +static int __init usb_hub_generic_init(void) > +{ > + return platform_driver_register(&usb_hub_generic_driver); > +} > +subsys_initcall(usb_hub_generic_init); > + > +static void __exit usb_hub_generic_exit(void) > +{ > + platform_driver_unregister(&usb_hub_generic_driver); > +} > +module_exit(usb_hub_generic_exit); > + > +MODULE_AUTHOR("Peter Chen <peter.chen@xxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Generic Onboard USB HUB driver"); > +MODULE_LICENSE("GPL"); > diff --git a/include/linux/usb/generic_onboard_hub.h b/include/linux/usb/generic_onboard_hub.h > new file mode 100644 > index 0000000..1b70ccc > --- /dev/null > +++ b/include/linux/usb/generic_onboard_hub.h > @@ -0,0 +1,11 @@ > +#ifndef __LINUX_USB_GENERIC_HUB_H > +#define __LINUX_USB_GENERIC_HUB_H > + > +struct usb_hub_generic_platform_data { > + int gpio_reset; > + int gpio_reset_polarity; > + int gpio_reset_duration_us; > + struct clk *ext_clk; > +}; Please document this structure in accordance with kernel documentation standards. > + > +#endif /* __LINUX_USB_GENERIC_HUB_H */ > -- > 1.9.1 > > -- > 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 -- 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
