2 * f_serial.c - generic USB serial function driver
4 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
5 * Copyright (C) 2008 by David Brownell
6 * Copyright (C) 2008 by Nokia Corporation
8 * This software is distributed under the terms of the GNU General
9 * Public License ("GPL") as published by the Free Software Foundation,
10 * either version 2 of that License or (at your option) any later version.
13 #include <linux/slab.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/device.h>
22 * This function packages a simple "generic serial" port with no real
23 * control mechanisms, just raw data transfer over two bulk endpoints.
25 * Because it's not standardized, this isn't as interoperable as the
26 * CDC ACM driver. However, for many purposes it's just as functional
27 * if you can arrange appropriate host side drivers.
36 static inline struct f_gser *func_to_gser(struct usb_function *f)
38 return container_of(f, struct f_gser, port.func);
41 /*-------------------------------------------------------------------------*/
43 /* interface descriptor: */
45 static struct usb_interface_descriptor gser_interface_desc = {
46 .bLength = USB_DT_INTERFACE_SIZE,
47 .bDescriptorType = USB_DT_INTERFACE,
48 /* .bInterfaceNumber = DYNAMIC */
50 .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
51 .bInterfaceSubClass = 0,
52 .bInterfaceProtocol = 0,
53 /* .iInterface = DYNAMIC */
56 /* full speed support: */
58 static struct usb_endpoint_descriptor gser_fs_in_desc = {
59 .bLength = USB_DT_ENDPOINT_SIZE,
60 .bDescriptorType = USB_DT_ENDPOINT,
61 .bEndpointAddress = USB_DIR_IN,
62 .bmAttributes = USB_ENDPOINT_XFER_BULK,
65 static struct usb_endpoint_descriptor gser_fs_out_desc = {
66 .bLength = USB_DT_ENDPOINT_SIZE,
67 .bDescriptorType = USB_DT_ENDPOINT,
68 .bEndpointAddress = USB_DIR_OUT,
69 .bmAttributes = USB_ENDPOINT_XFER_BULK,
72 static struct usb_descriptor_header *gser_fs_function[] = {
73 (struct usb_descriptor_header *) &gser_interface_desc,
74 (struct usb_descriptor_header *) &gser_fs_in_desc,
75 (struct usb_descriptor_header *) &gser_fs_out_desc,
79 /* high speed support: */
81 static struct usb_endpoint_descriptor gser_hs_in_desc = {
82 .bLength = USB_DT_ENDPOINT_SIZE,
83 .bDescriptorType = USB_DT_ENDPOINT,
84 .bmAttributes = USB_ENDPOINT_XFER_BULK,
85 .wMaxPacketSize = cpu_to_le16(512),
88 static struct usb_endpoint_descriptor gser_hs_out_desc = {
89 .bLength = USB_DT_ENDPOINT_SIZE,
90 .bDescriptorType = USB_DT_ENDPOINT,
91 .bmAttributes = USB_ENDPOINT_XFER_BULK,
92 .wMaxPacketSize = cpu_to_le16(512),
95 static struct usb_descriptor_header *gser_hs_function[] = {
96 (struct usb_descriptor_header *) &gser_interface_desc,
97 (struct usb_descriptor_header *) &gser_hs_in_desc,
98 (struct usb_descriptor_header *) &gser_hs_out_desc,
102 static struct usb_endpoint_descriptor gser_ss_in_desc = {
103 .bLength = USB_DT_ENDPOINT_SIZE,
104 .bDescriptorType = USB_DT_ENDPOINT,
105 .bmAttributes = USB_ENDPOINT_XFER_BULK,
106 .wMaxPacketSize = cpu_to_le16(1024),
109 static struct usb_endpoint_descriptor gser_ss_out_desc = {
110 .bLength = USB_DT_ENDPOINT_SIZE,
111 .bDescriptorType = USB_DT_ENDPOINT,
112 .bmAttributes = USB_ENDPOINT_XFER_BULK,
113 .wMaxPacketSize = cpu_to_le16(1024),
116 static struct usb_ss_ep_comp_descriptor gser_ss_bulk_comp_desc = {
117 .bLength = sizeof gser_ss_bulk_comp_desc,
118 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
121 static struct usb_descriptor_header *gser_ss_function[] = {
122 (struct usb_descriptor_header *) &gser_interface_desc,
123 (struct usb_descriptor_header *) &gser_ss_in_desc,
124 (struct usb_descriptor_header *) &gser_ss_bulk_comp_desc,
125 (struct usb_descriptor_header *) &gser_ss_out_desc,
126 (struct usb_descriptor_header *) &gser_ss_bulk_comp_desc,
130 /* string descriptors: */
132 static struct usb_string gser_string_defs[] = {
133 [0].s = "Generic Serial",
134 { } /* end of list */
137 static struct usb_gadget_strings gser_string_table = {
138 .language = 0x0409, /* en-us */
139 .strings = gser_string_defs,
142 static struct usb_gadget_strings *gser_strings[] = {
147 /*-------------------------------------------------------------------------*/
149 static int gser_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
151 struct f_gser *gser = func_to_gser(f);
152 struct usb_composite_dev *cdev = f->config->cdev;
154 /* we know alt == 0, so this is an activation or a reset */
156 if (gser->port.in->driver_data) {
157 dev_dbg(&cdev->gadget->dev,
158 "reset generic ttyGS%d\n", gser->port_num);
159 gserial_disconnect(&gser->port);
161 if (!gser->port.in->desc || !gser->port.out->desc) {
162 dev_dbg(&cdev->gadget->dev,
163 "activate generic ttyGS%d\n", gser->port_num);
164 if (config_ep_by_speed(cdev->gadget, f, gser->port.in) ||
165 config_ep_by_speed(cdev->gadget, f, gser->port.out)) {
166 gser->port.in->desc = NULL;
167 gser->port.out->desc = NULL;
171 gserial_connect(&gser->port, gser->port_num);
175 static void gser_disable(struct usb_function *f)
177 struct f_gser *gser = func_to_gser(f);
178 struct usb_composite_dev *cdev = f->config->cdev;
180 dev_dbg(&cdev->gadget->dev,
181 "generic ttyGS%d deactivated\n", gser->port_num);
182 gserial_disconnect(&gser->port);
185 /*-------------------------------------------------------------------------*/
187 /* serial function driver setup/binding */
189 static int gser_bind(struct usb_configuration *c, struct usb_function *f)
191 struct usb_composite_dev *cdev = c->cdev;
192 struct f_gser *gser = func_to_gser(f);
196 /* REVISIT might want instance-specific strings to help
197 * distinguish instances ...
200 /* maybe allocate device-global string ID */
201 if (gser_string_defs[0].id == 0) {
202 status = usb_string_id(c->cdev);
205 gser_string_defs[0].id = status;
208 /* allocate instance-specific interface IDs */
209 status = usb_interface_id(c, f);
212 gser->data_id = status;
213 gser_interface_desc.bInterfaceNumber = status;
217 /* allocate instance-specific endpoints */
218 ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_in_desc);
222 ep->driver_data = cdev; /* claim */
224 ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_out_desc);
228 ep->driver_data = cdev; /* claim */
230 /* support all relevant hardware speeds... we expect that when
231 * hardware is dual speed, all bulk-capable endpoints work at
234 gser_hs_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress;
235 gser_hs_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress;
237 gser_ss_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress;
238 gser_ss_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress;
240 status = usb_assign_descriptors(f, gser_fs_function, gser_hs_function,
244 dev_dbg(&cdev->gadget->dev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n",
246 gadget_is_superspeed(c->cdev->gadget) ? "super" :
247 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
248 gser->port.in->name, gser->port.out->name);
252 /* we might as well release our claims on endpoints */
254 gser->port.out->driver_data = NULL;
256 gser->port.in->driver_data = NULL;
258 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
263 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
265 return container_of(to_config_group(item), struct f_serial_opts,
269 CONFIGFS_ATTR_STRUCT(f_serial_opts);
270 static ssize_t f_serial_attr_show(struct config_item *item,
271 struct configfs_attribute *attr,
274 struct f_serial_opts *opts = to_f_serial_opts(item);
275 struct f_serial_opts_attribute *f_serial_opts_attr =
276 container_of(attr, struct f_serial_opts_attribute, attr);
279 if (f_serial_opts_attr->show)
280 ret = f_serial_opts_attr->show(opts, page);
285 static void serial_attr_release(struct config_item *item)
287 struct f_serial_opts *opts = to_f_serial_opts(item);
289 usb_put_function_instance(&opts->func_inst);
292 static struct configfs_item_operations serial_item_ops = {
293 .release = serial_attr_release,
294 .show_attribute = f_serial_attr_show,
297 static ssize_t f_serial_port_num_show(struct f_serial_opts *opts, char *page)
299 return sprintf(page, "%u\n", opts->port_num);
302 static struct f_serial_opts_attribute f_serial_port_num =
303 __CONFIGFS_ATTR_RO(port_num, f_serial_port_num_show);
305 static struct configfs_attribute *acm_attrs[] = {
306 &f_serial_port_num.attr,
310 static struct config_item_type serial_func_type = {
311 .ct_item_ops = &serial_item_ops,
312 .ct_attrs = acm_attrs,
313 .ct_owner = THIS_MODULE,
316 static void gser_free_inst(struct usb_function_instance *f)
318 struct f_serial_opts *opts;
320 opts = container_of(f, struct f_serial_opts, func_inst);
321 gserial_free_line(opts->port_num);
325 static struct usb_function_instance *gser_alloc_inst(void)
327 struct f_serial_opts *opts;
330 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
332 return ERR_PTR(-ENOMEM);
334 opts->func_inst.free_func_inst = gser_free_inst;
335 ret = gserial_alloc_line(&opts->port_num);
340 config_group_init_type_name(&opts->func_inst.group, "",
343 return &opts->func_inst;
346 static void gser_free(struct usb_function *f)
348 struct f_gser *serial;
350 serial = func_to_gser(f);
354 static void gser_unbind(struct usb_configuration *c, struct usb_function *f)
356 usb_free_all_descriptors(f);
359 static struct usb_function *gser_alloc(struct usb_function_instance *fi)
362 struct f_serial_opts *opts;
364 /* allocate and initialize one new instance */
365 gser = kzalloc(sizeof(*gser), GFP_KERNEL);
367 return ERR_PTR(-ENOMEM);
369 opts = container_of(fi, struct f_serial_opts, func_inst);
371 gser->port_num = opts->port_num;
373 gser->port.func.name = "gser";
374 gser->port.func.strings = gser_strings;
375 gser->port.func.bind = gser_bind;
376 gser->port.func.unbind = gser_unbind;
377 gser->port.func.set_alt = gser_set_alt;
378 gser->port.func.disable = gser_disable;
379 gser->port.func.free_func = gser_free;
381 return &gser->port.func;
384 DECLARE_USB_FUNCTION_INIT(gser, gser_alloc_inst, gser_alloc);
385 MODULE_LICENSE("GPL");
386 MODULE_AUTHOR("Al Borchers");
387 MODULE_AUTHOR("David Brownell");