diff options
Diffstat (limited to 'drivers/usb/core/ledtrig-usbport.c')
-rw-r--r-- | drivers/usb/core/ledtrig-usbport.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/drivers/usb/core/ledtrig-usbport.c b/drivers/usb/core/ledtrig-usbport.c new file mode 100644 index 000000000..ba371a24f --- /dev/null +++ b/drivers/usb/core/ledtrig-usbport.c @@ -0,0 +1,368 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * USB port LED trigger + * + * Copyright (C) 2016 Rafał Miłecki <rafal@milecki.pl> + */ + +#include <linux/device.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/usb.h> +#include <linux/usb/of.h> + +struct usbport_trig_data { + struct led_classdev *led_cdev; + struct list_head ports; + struct notifier_block nb; + int count; /* Amount of connected matching devices */ +}; + +struct usbport_trig_port { + struct usbport_trig_data *data; + struct usb_device *hub; + int portnum; + char *port_name; + bool observed; + struct device_attribute attr; + struct list_head list; +}; + +/*************************************** + * Helpers + ***************************************/ + +/* + * usbport_trig_usb_dev_observed - Check if dev is connected to observed port + */ +static bool usbport_trig_usb_dev_observed(struct usbport_trig_data *usbport_data, + struct usb_device *usb_dev) +{ + struct usbport_trig_port *port; + + if (!usb_dev->parent) + return false; + + list_for_each_entry(port, &usbport_data->ports, list) { + if (usb_dev->parent == port->hub && + usb_dev->portnum == port->portnum) + return port->observed; + } + + return false; +} + +static int usbport_trig_usb_dev_check(struct usb_device *usb_dev, void *data) +{ + struct usbport_trig_data *usbport_data = data; + + if (usbport_trig_usb_dev_observed(usbport_data, usb_dev)) + usbport_data->count++; + + return 0; +} + +/* + * usbport_trig_update_count - Recalculate amount of connected matching devices + */ +static void usbport_trig_update_count(struct usbport_trig_data *usbport_data) +{ + struct led_classdev *led_cdev = usbport_data->led_cdev; + + usbport_data->count = 0; + usb_for_each_dev(usbport_data, usbport_trig_usb_dev_check); + led_set_brightness(led_cdev, usbport_data->count ? LED_FULL : LED_OFF); +} + +/*************************************** + * Device attr + ***************************************/ + +static ssize_t usbport_trig_port_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct usbport_trig_port *port = container_of(attr, + struct usbport_trig_port, + attr); + + return sprintf(buf, "%d\n", port->observed) + 1; +} + +static ssize_t usbport_trig_port_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct usbport_trig_port *port = container_of(attr, + struct usbport_trig_port, + attr); + + if (!strcmp(buf, "0") || !strcmp(buf, "0\n")) + port->observed = 0; + else if (!strcmp(buf, "1") || !strcmp(buf, "1\n")) + port->observed = 1; + else + return -EINVAL; + + usbport_trig_update_count(port->data); + + return size; +} + +static struct attribute *ports_attrs[] = { + NULL, +}; + +static const struct attribute_group ports_group = { + .name = "ports", + .attrs = ports_attrs, +}; + +/*************************************** + * Adding & removing ports + ***************************************/ + +/* + * usbport_trig_port_observed - Check if port should be observed + */ +static bool usbport_trig_port_observed(struct usbport_trig_data *usbport_data, + struct usb_device *usb_dev, int port1) +{ + struct device *dev = usbport_data->led_cdev->dev; + struct device_node *led_np = dev->of_node; + struct of_phandle_args args; + struct device_node *port_np; + int count, i; + + if (!led_np) + return false; + + /* + * Get node of port being added + * + * FIXME: This is really the device node of the connected device + */ + port_np = usb_of_get_device_node(usb_dev, port1); + if (!port_np) + return false; + + of_node_put(port_np); + + /* Amount of trigger sources for this LED */ + count = of_count_phandle_with_args(led_np, "trigger-sources", + "#trigger-source-cells"); + if (count < 0) { + dev_warn(dev, "Failed to get trigger sources for %pOF\n", + led_np); + return false; + } + + /* Check list of sources for this specific port */ + for (i = 0; i < count; i++) { + int err; + + err = of_parse_phandle_with_args(led_np, "trigger-sources", + "#trigger-source-cells", i, + &args); + if (err) { + dev_err(dev, "Failed to get trigger source phandle at index %d: %d\n", + i, err); + continue; + } + + of_node_put(args.np); + + if (args.np == port_np) + return true; + } + + return false; +} + +static int usbport_trig_add_port(struct usbport_trig_data *usbport_data, + struct usb_device *usb_dev, + const char *hub_name, int portnum) +{ + struct led_classdev *led_cdev = usbport_data->led_cdev; + struct usbport_trig_port *port; + size_t len; + int err; + + port = kzalloc(sizeof(*port), GFP_KERNEL); + if (!port) { + err = -ENOMEM; + goto err_out; + } + + port->data = usbport_data; + port->hub = usb_dev; + port->portnum = portnum; + port->observed = usbport_trig_port_observed(usbport_data, usb_dev, + portnum); + + len = strlen(hub_name) + 8; + port->port_name = kzalloc(len, GFP_KERNEL); + if (!port->port_name) { + err = -ENOMEM; + goto err_free_port; + } + snprintf(port->port_name, len, "%s-port%d", hub_name, portnum); + + sysfs_attr_init(&port->attr.attr); + port->attr.attr.name = port->port_name; + port->attr.attr.mode = S_IRUSR | S_IWUSR; + port->attr.show = usbport_trig_port_show; + port->attr.store = usbport_trig_port_store; + + err = sysfs_add_file_to_group(&led_cdev->dev->kobj, &port->attr.attr, + ports_group.name); + if (err) + goto err_free_port_name; + + list_add_tail(&port->list, &usbport_data->ports); + + return 0; + +err_free_port_name: + kfree(port->port_name); +err_free_port: + kfree(port); +err_out: + return err; +} + +static int usbport_trig_add_usb_dev_ports(struct usb_device *usb_dev, + void *data) +{ + struct usbport_trig_data *usbport_data = data; + int i; + + for (i = 1; i <= usb_dev->maxchild; i++) + usbport_trig_add_port(usbport_data, usb_dev, + dev_name(&usb_dev->dev), i); + + return 0; +} + +static void usbport_trig_remove_port(struct usbport_trig_data *usbport_data, + struct usbport_trig_port *port) +{ + struct led_classdev *led_cdev = usbport_data->led_cdev; + + list_del(&port->list); + sysfs_remove_file_from_group(&led_cdev->dev->kobj, &port->attr.attr, + ports_group.name); + kfree(port->port_name); + kfree(port); +} + +static void usbport_trig_remove_usb_dev_ports(struct usbport_trig_data *usbport_data, + struct usb_device *usb_dev) +{ + struct usbport_trig_port *port, *tmp; + + list_for_each_entry_safe(port, tmp, &usbport_data->ports, list) { + if (port->hub == usb_dev) + usbport_trig_remove_port(usbport_data, port); + } +} + +/*************************************** + * Init, exit, etc. + ***************************************/ + +static int usbport_trig_notify(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct usbport_trig_data *usbport_data = + container_of(nb, struct usbport_trig_data, nb); + struct led_classdev *led_cdev = usbport_data->led_cdev; + struct usb_device *usb_dev = data; + bool observed; + + observed = usbport_trig_usb_dev_observed(usbport_data, usb_dev); + + switch (action) { + case USB_DEVICE_ADD: + usbport_trig_add_usb_dev_ports(usb_dev, usbport_data); + if (observed && usbport_data->count++ == 0) + led_set_brightness(led_cdev, LED_FULL); + return NOTIFY_OK; + case USB_DEVICE_REMOVE: + usbport_trig_remove_usb_dev_ports(usbport_data, usb_dev); + if (observed && --usbport_data->count == 0) + led_set_brightness(led_cdev, LED_OFF); + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + +static int usbport_trig_activate(struct led_classdev *led_cdev) +{ + struct usbport_trig_data *usbport_data; + int err; + + usbport_data = kzalloc(sizeof(*usbport_data), GFP_KERNEL); + if (!usbport_data) + return -ENOMEM; + usbport_data->led_cdev = led_cdev; + + /* List of ports */ + INIT_LIST_HEAD(&usbport_data->ports); + err = sysfs_create_group(&led_cdev->dev->kobj, &ports_group); + if (err) + goto err_free; + usb_for_each_dev(usbport_data, usbport_trig_add_usb_dev_ports); + usbport_trig_update_count(usbport_data); + + /* Notifications */ + usbport_data->nb.notifier_call = usbport_trig_notify; + led_set_trigger_data(led_cdev, usbport_data); + usb_register_notify(&usbport_data->nb); + return 0; + +err_free: + kfree(usbport_data); + return err; +} + +static void usbport_trig_deactivate(struct led_classdev *led_cdev) +{ + struct usbport_trig_data *usbport_data = led_get_trigger_data(led_cdev); + struct usbport_trig_port *port, *tmp; + + list_for_each_entry_safe(port, tmp, &usbport_data->ports, list) { + usbport_trig_remove_port(usbport_data, port); + } + + sysfs_remove_group(&led_cdev->dev->kobj, &ports_group); + + usb_unregister_notify(&usbport_data->nb); + + kfree(usbport_data); +} + +static struct led_trigger usbport_led_trigger = { + .name = "usbport", + .activate = usbport_trig_activate, + .deactivate = usbport_trig_deactivate, +}; + +static int __init usbport_trig_init(void) +{ + return led_trigger_register(&usbport_led_trigger); +} + +static void __exit usbport_trig_exit(void) +{ + led_trigger_unregister(&usbport_led_trigger); +} + +module_init(usbport_trig_init); +module_exit(usbport_trig_exit); + +MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>"); +MODULE_DESCRIPTION("USB port trigger"); +MODULE_LICENSE("GPL v2"); |