summaryrefslogtreecommitdiffstats
path: root/drivers/usb/gadget/function/f_serial.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/usb/gadget/function/f_serial.c399
1 files changed, 399 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/f_serial.c b/drivers/usb/gadget/function/f_serial.c
new file mode 100644
index 000000000..a9480b9e3
--- /dev/null
+++ b/drivers/usb/gadget/function/f_serial.c
@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * 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
+ */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+
+#include "u_serial.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 f_gser {
+ struct gserial port;
+ u8 data_id;
+ u8 port_num;
+};
+
+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 = {
+ .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 = {
+ .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 = {
+ .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[] = {
+ (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 = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor gser_hs_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *gser_hs_function[] = {
+ (struct usb_descriptor_header *) &gser_interface_desc,
+ (struct usb_descriptor_header *) &gser_hs_in_desc,
+ (struct usb_descriptor_header *) &gser_hs_out_desc,
+ NULL,
+};
+
+static struct usb_endpoint_descriptor gser_ss_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+
+static struct usb_endpoint_descriptor gser_ss_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor gser_ss_bulk_comp_desc = {
+ .bLength = sizeof gser_ss_bulk_comp_desc,
+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+};
+
+static struct usb_descriptor_header *gser_ss_function[] = {
+ (struct usb_descriptor_header *) &gser_interface_desc,
+ (struct usb_descriptor_header *) &gser_ss_in_desc,
+ (struct usb_descriptor_header *) &gser_ss_bulk_comp_desc,
+ (struct usb_descriptor_header *) &gser_ss_out_desc,
+ (struct usb_descriptor_header *) &gser_ss_bulk_comp_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->enabled) {
+ dev_dbg(&cdev->gadget->dev,
+ "reset generic ttyGS%d\n", gser->port_num);
+ gserial_disconnect(&gser->port);
+ }
+ if (!gser->port.in->desc || !gser->port.out->desc) {
+ dev_dbg(&cdev->gadget->dev,
+ "activate generic ttyGS%d\n", gser->port_num);
+ if (config_ep_by_speed(cdev->gadget, f, gser->port.in) ||
+ config_ep_by_speed(cdev->gadget, f, gser->port.out)) {
+ gser->port.in->desc = NULL;
+ gser->port.out->desc = NULL;
+ return -EINVAL;
+ }
+ }
+ 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;
+
+ dev_dbg(&cdev->gadget->dev,
+ "generic ttyGS%d deactivated\n", gser->port_num);
+ gserial_disconnect(&gser->port);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* serial function driver setup/binding */
+
+static int 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;
+
+ /* 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 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 = usb_ep_autoconfig(cdev->gadget, &gser_fs_out_desc);
+ if (!ep)
+ goto fail;
+ gser->port.out = ep;
+
+ /* support all relevant hardware speeds... we expect that when
+ * hardware is dual speed, all bulk-capable endpoints work at
+ * both speeds
+ */
+ gser_hs_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress;
+ gser_hs_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress;
+
+ gser_ss_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress;
+ gser_ss_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress;
+
+ status = usb_assign_descriptors(f, gser_fs_function, gser_hs_function,
+ gser_ss_function, gser_ss_function);
+ if (status)
+ goto fail;
+ dev_dbg(&cdev->gadget->dev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n",
+ gser->port_num,
+ gadget_is_superspeed(c->cdev->gadget) ? "super" :
+ gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+ gser->port.in->name, gser->port.out->name);
+ return 0;
+
+fail:
+ ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
+
+ return status;
+}
+
+static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_serial_opts,
+ func_inst.group);
+}
+
+static void serial_attr_release(struct config_item *item)
+{
+ struct f_serial_opts *opts = to_f_serial_opts(item);
+
+ usb_put_function_instance(&opts->func_inst);
+}
+
+static struct configfs_item_operations serial_item_ops = {
+ .release = serial_attr_release,
+};
+
+#ifdef CONFIG_U_SERIAL_CONSOLE
+
+static ssize_t f_serial_console_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ return gserial_set_console(to_f_serial_opts(item)->port_num,
+ page, count);
+}
+
+static ssize_t f_serial_console_show(struct config_item *item, char *page)
+{
+ return gserial_get_console(to_f_serial_opts(item)->port_num, page);
+}
+
+CONFIGFS_ATTR(f_serial_, console);
+
+#endif /* CONFIG_U_SERIAL_CONSOLE */
+
+static ssize_t f_serial_port_num_show(struct config_item *item, char *page)
+{
+ return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
+}
+
+CONFIGFS_ATTR_RO(f_serial_, port_num);
+
+static struct configfs_attribute *acm_attrs[] = {
+#ifdef CONFIG_U_SERIAL_CONSOLE
+ &f_serial_attr_console,
+#endif
+ &f_serial_attr_port_num,
+ NULL,
+};
+
+static const struct config_item_type serial_func_type = {
+ .ct_item_ops = &serial_item_ops,
+ .ct_attrs = acm_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static void gser_free_inst(struct usb_function_instance *f)
+{
+ struct f_serial_opts *opts;
+
+ opts = container_of(f, struct f_serial_opts, func_inst);
+ gserial_free_line(opts->port_num);
+ kfree(opts);
+}
+
+static struct usb_function_instance *gser_alloc_inst(void)
+{
+ struct f_serial_opts *opts;
+ int ret;
+
+ opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+ if (!opts)
+ return ERR_PTR(-ENOMEM);
+
+ opts->func_inst.free_func_inst = gser_free_inst;
+ ret = gserial_alloc_line(&opts->port_num);
+ if (ret) {
+ kfree(opts);
+ return ERR_PTR(ret);
+ }
+ config_group_init_type_name(&opts->func_inst.group, "",
+ &serial_func_type);
+
+ return &opts->func_inst;
+}
+
+static void gser_free(struct usb_function *f)
+{
+ struct f_gser *serial;
+
+ serial = func_to_gser(f);
+ kfree(serial);
+}
+
+static void gser_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct f_gser *gser = func_to_gser(f);
+
+ /* Ensure port is disconnected before unbinding */
+ gserial_disconnect(&gser->port);
+ usb_free_all_descriptors(f);
+}
+
+static void gser_resume(struct usb_function *f)
+{
+ struct f_gser *gser = func_to_gser(f);
+
+ gserial_resume(&gser->port);
+}
+
+static void gser_suspend(struct usb_function *f)
+{
+ struct f_gser *gser = func_to_gser(f);
+
+ gserial_suspend(&gser->port);
+}
+
+static struct usb_function *gser_alloc(struct usb_function_instance *fi)
+{
+ struct f_gser *gser;
+ struct f_serial_opts *opts;
+
+ /* allocate and initialize one new instance */
+ gser = kzalloc(sizeof(*gser), GFP_KERNEL);
+ if (!gser)
+ return ERR_PTR(-ENOMEM);
+
+ opts = container_of(fi, struct f_serial_opts, func_inst);
+
+ gser->port_num = opts->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;
+ gser->port.func.free_func = gser_free;
+ gser->port.func.resume = gser_resume;
+ gser->port.func.suspend = gser_suspend;
+
+ return &gser->port.func;
+}
+
+DECLARE_USB_FUNCTION_INIT(gser, gser_alloc_inst, gser_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Al Borchers");
+MODULE_AUTHOR("David Brownell");