diff options
Diffstat (limited to 'drivers/usb/gadget/f_serial.c')
-rw-r--r-- | drivers/usb/gadget/f_serial.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_serial.c b/drivers/usb/gadget/f_serial.c new file mode 100644 index 000000000000..1b6bde9aaed5 --- /dev/null +++ b/drivers/usb/gadget/f_serial.c @@ -0,0 +1,296 @@ +/* + * f_serial.c - generic USB serial function driver + * + * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com) + * Copyright (C) 2008 by David Brownell + * Copyright (C) 2008 by Nokia Corporation + * + * This software is distributed under the terms of the GNU General + * Public License ("GPL") as published by the Free Software Foundation, + * either version 2 of that License or (at your option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/device.h> + +#include "u_serial.h" +#include "gadget_chips.h" + + +/* + * This function packages a simple "generic serial" port with no real + * control mechanisms, just raw data transfer over two bulk endpoints. + * + * Because it's not standardized, this isn't as interoperable as the + * CDC ACM driver. However, for many purposes it's just as functional + * if you can arrange appropriate host side drivers. + */ + +struct gser_descs { + struct usb_endpoint_descriptor *in; + struct usb_endpoint_descriptor *out; +}; + +struct f_gser { + struct gserial port; + u8 data_id; + u8 port_num; + + struct usb_descriptor_header **fs_function; + struct gser_descs fs; + struct usb_descriptor_header **hs_function; + struct gser_descs hs; +}; + +static inline struct f_gser *func_to_gser(struct usb_function *f) +{ + return container_of(f, struct f_gser, port.func); +} + +/*-------------------------------------------------------------------------*/ + +/* interface descriptor: */ + +static struct usb_interface_descriptor gser_interface_desc __initdata = { + .bLength = USB_DT_INTERFACE_SIZE, + .bDescriptorType = USB_DT_INTERFACE, + /* .bInterfaceNumber = DYNAMIC */ + .bNumEndpoints = 2, + .bInterfaceClass = USB_CLASS_VENDOR_SPEC, + .bInterfaceSubClass = 0, + .bInterfaceProtocol = 0, + /* .iInterface = DYNAMIC */ +}; + +/* full speed support: */ + +static struct usb_endpoint_descriptor gser_fs_in_desc __initdata = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_BULK, +}; + +static struct usb_endpoint_descriptor gser_fs_out_desc __initdata = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + .bEndpointAddress = USB_DIR_OUT, + .bmAttributes = USB_ENDPOINT_XFER_BULK, +}; + +static struct usb_descriptor_header *gser_fs_function[] __initdata = { + (struct usb_descriptor_header *) &gser_interface_desc, + (struct usb_descriptor_header *) &gser_fs_in_desc, + (struct usb_descriptor_header *) &gser_fs_out_desc, + NULL, +}; + +/* high speed support: */ + +static struct usb_endpoint_descriptor gser_hs_in_desc __initdata = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = __constant_cpu_to_le16(512), +}; + +static struct usb_endpoint_descriptor gser_hs_out_desc __initdata = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = __constant_cpu_to_le16(512), +}; + +static struct usb_descriptor_header *gser_hs_function[] __initdata = { + (struct usb_descriptor_header *) &gser_interface_desc, + (struct usb_descriptor_header *) &gser_hs_in_desc, + (struct usb_descriptor_header *) &gser_hs_out_desc, + NULL, +}; + +/* string descriptors: */ + +static struct usb_string gser_string_defs[] = { + [0].s = "Generic Serial", + { } /* end of list */ +}; + +static struct usb_gadget_strings gser_string_table = { + .language = 0x0409, /* en-us */ + .strings = gser_string_defs, +}; + +static struct usb_gadget_strings *gser_strings[] = { + &gser_string_table, + NULL, +}; + +/*-------------------------------------------------------------------------*/ + +static int gser_set_alt(struct usb_function *f, unsigned intf, unsigned alt) +{ + struct f_gser *gser = func_to_gser(f); + struct usb_composite_dev *cdev = f->config->cdev; + + /* we know alt == 0, so this is an activation or a reset */ + + if (gser->port.in->driver_data) { + DBG(cdev, "reset generic ttyGS%d\n", gser->port_num); + gserial_disconnect(&gser->port); + } else { + DBG(cdev, "activate generic ttyGS%d\n", gser->port_num); + gser->port.in_desc = ep_choose(cdev->gadget, + gser->hs.in, gser->fs.in); + gser->port.out_desc = ep_choose(cdev->gadget, + gser->hs.out, gser->fs.out); + } + gserial_connect(&gser->port, gser->port_num); + return 0; +} + +static void gser_disable(struct usb_function *f) +{ + struct f_gser *gser = func_to_gser(f); + struct usb_composite_dev *cdev = f->config->cdev; + + DBG(cdev, "generic ttyGS%d deactivated\n", gser->port_num); + gserial_disconnect(&gser->port); +} + +/*-------------------------------------------------------------------------*/ + +/* serial function driver setup/binding */ + +static int __init +gser_bind(struct usb_configuration *c, struct usb_function *f) +{ + struct usb_composite_dev *cdev = c->cdev; + struct f_gser *gser = func_to_gser(f); + int status; + struct usb_ep *ep; + + /* allocate instance-specific interface IDs */ + status = usb_interface_id(c, f); + if (status < 0) + goto fail; + gser->data_id = status; + gser_interface_desc.bInterfaceNumber = status; + + status = -ENODEV; + + /* allocate instance-specific endpoints */ + ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_in_desc); + if (!ep) + goto fail; + gser->port.in = ep; + ep->driver_data = cdev; /* claim */ + + ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_out_desc); + if (!ep) + goto fail; + gser->port.out = ep; + ep->driver_data = cdev; /* claim */ + + /* copy descriptors, and track endpoint copies */ + f->descriptors = usb_copy_descriptors(gser_fs_function); + + gser->fs.in = usb_find_endpoint(gser_fs_function, + f->descriptors, &gser_fs_in_desc); + gser->fs.out = usb_find_endpoint(gser_fs_function, + f->descriptors, &gser_fs_out_desc); + + + /* support all relevant hardware speeds... we expect that when + * hardware is dual speed, all bulk-capable endpoints work at + * both speeds + */ + if (gadget_is_dualspeed(c->cdev->gadget)) { + gser_hs_in_desc.bEndpointAddress = + gser_fs_in_desc.bEndpointAddress; + gser_hs_out_desc.bEndpointAddress = + gser_fs_out_desc.bEndpointAddress; + + /* copy descriptors, and track endpoint copies */ + f->hs_descriptors = usb_copy_descriptors(gser_hs_function); + + gser->hs.in = usb_find_endpoint(gser_hs_function, + f->hs_descriptors, &gser_hs_in_desc); + gser->hs.out = usb_find_endpoint(gser_hs_function, + f->hs_descriptors, &gser_hs_out_desc); + } + + DBG(cdev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n", + gser->port_num, + gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full", + gser->port.in->name, gser->port.out->name); + return 0; + +fail: + /* we might as well release our claims on endpoints */ + if (gser->port.out) + gser->port.out->driver_data = NULL; + if (gser->port.in) + gser->port.in->driver_data = NULL; + + ERROR(cdev, "%s: can't bind, err %d\n", f->name, status); + + return status; +} + +static void +gser_unbind(struct usb_configuration *c, struct usb_function *f) +{ + if (gadget_is_dualspeed(c->cdev->gadget)) + usb_free_descriptors(f->hs_descriptors); + usb_free_descriptors(f->descriptors); + kfree(func_to_gser(f)); +} + +/** + * gser_bind_config - add a generic serial function to a configuration + * @c: the configuration to support the serial instance + * @port_num: /dev/ttyGS* port this interface will use + * Context: single threaded during gadget setup + * + * Returns zero on success, else negative errno. + * + * Caller must have called @gserial_setup() with enough ports to + * handle all the ones it binds. Caller is also responsible + * for calling @gserial_cleanup() before module unload. + */ +int __init gser_bind_config(struct usb_configuration *c, u8 port_num) +{ + struct f_gser *gser; + int status; + + /* REVISIT might want instance-specific strings to help + * distinguish instances ... + */ + + /* maybe allocate device-global string ID */ + if (gser_string_defs[0].id == 0) { + status = usb_string_id(c->cdev); + if (status < 0) + return status; + gser_string_defs[0].id = status; + } + + /* allocate and initialize one new instance */ + gser = kzalloc(sizeof *gser, GFP_KERNEL); + if (!gser) + return -ENOMEM; + + gser->port_num = port_num; + + gser->port.func.name = "gser"; + gser->port.func.strings = gser_strings; + gser->port.func.bind = gser_bind; + gser->port.func.unbind = gser_unbind; + gser->port.func.set_alt = gser_set_alt; + gser->port.func.disable = gser_disable; + + status = usb_add_function(c, &gser->port.func); + if (status) + kfree(gser); + return status; +} |