diff options
Diffstat (limited to 'drivers/usb/gadget/f_acm.c')
| -rw-r--r-- | drivers/usb/gadget/f_acm.c | 589 |
1 files changed, 589 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_acm.c b/drivers/usb/gadget/f_acm.c new file mode 100644 index 000000000000..d8faccf27895 --- /dev/null +++ b/drivers/usb/gadget/f_acm.c @@ -0,0 +1,589 @@ +/* + * f_acm.c -- USB CDC serial (ACM) 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. + */ + +/* #define VERBOSE_DEBUG */ + +#include <linux/kernel.h> +#include <linux/device.h> + +#include "u_serial.h" +#include "gadget_chips.h" + + +/* + * This CDC ACM function support just wraps control functions and + * notifications around the generic serial-over-usb code. + * + * Because CDC ACM is standardized by the USB-IF, many host operating + * systems have drivers for it. Accordingly, ACM is the preferred + * interop solution for serial-port type connections. The control + * models are often not necessary, and in any case don't do much in + * this bare-bones implementation. + * + * Note that even MS-Windows has some support for ACM. However, that + * support is somewhat broken because when you use ACM in a composite + * device, having multiple interfaces confuses the poor OS. It doesn't + * seem to understand CDC Union descriptors. The new "association" + * descriptors (roughly equivalent to CDC Unions) may sometimes help. + */ + +struct acm_ep_descs { + struct usb_endpoint_descriptor *in; + struct usb_endpoint_descriptor *out; + struct usb_endpoint_descriptor *notify; +}; + +struct f_acm { + struct gserial port; + u8 ctrl_id, data_id; + u8 port_num; + + struct usb_descriptor_header **fs_function; + struct acm_ep_descs fs; + struct usb_descriptor_header **hs_function; + struct acm_ep_descs hs; + + struct usb_ep *notify; + struct usb_endpoint_descriptor *notify_desc; + + struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */ + u16 port_handshake_bits; +#define RS232_RTS (1 << 1) /* unused with full duplex */ +#define RS232_DTR (1 << 0) /* host is ready for data r/w */ +}; + +static inline struct f_acm *func_to_acm(struct usb_function *f) +{ + return container_of(f, struct f_acm, port.func); +} + +/*-------------------------------------------------------------------------*/ + +/* notification endpoint uses smallish and infrequent fixed-size messages */ + +#define GS_LOG2_NOTIFY_INTERVAL 5 /* 1 << 5 == 32 msec */ +#define GS_NOTIFY_MAXPACKET 8 + +/* interface and class descriptors: */ + +static struct usb_interface_descriptor acm_control_interface_desc __initdata = { + .bLength = USB_DT_INTERFACE_SIZE, + .bDescriptorType = USB_DT_INTERFACE, + /* .bInterfaceNumber = DYNAMIC */ + .bNumEndpoints = 1, + .bInterfaceClass = USB_CLASS_COMM, + .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM, + .bInterfaceProtocol = USB_CDC_ACM_PROTO_AT_V25TER, + /* .iInterface = DYNAMIC */ +}; + +static struct usb_interface_descriptor acm_data_interface_desc __initdata = { + .bLength = USB_DT_INTERFACE_SIZE, + .bDescriptorType = USB_DT_INTERFACE, + /* .bInterfaceNumber = DYNAMIC */ + .bNumEndpoints = 2, + .bInterfaceClass = USB_CLASS_CDC_DATA, + .bInterfaceSubClass = 0, + .bInterfaceProtocol = 0, + /* .iInterface = DYNAMIC */ +}; + +static struct usb_cdc_header_desc acm_header_desc __initdata = { + .bLength = sizeof(acm_header_desc), + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubType = USB_CDC_HEADER_TYPE, + .bcdCDC = __constant_cpu_to_le16(0x0110), +}; + +static struct usb_cdc_call_mgmt_descriptor +acm_call_mgmt_descriptor __initdata = { + .bLength = sizeof(acm_call_mgmt_descriptor), + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE, + .bmCapabilities = 0, + /* .bDataInterface = DYNAMIC */ +}; + +static struct usb_cdc_acm_descriptor acm_descriptor __initdata = { + .bLength = sizeof(acm_descriptor), + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubType = USB_CDC_ACM_TYPE, + .bmCapabilities = (1 << 1), +}; + +static struct usb_cdc_union_desc acm_union_desc __initdata = { + .bLength = sizeof(acm_union_desc), + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubType = USB_CDC_UNION_TYPE, + /* .bMasterInterface0 = DYNAMIC */ + /* .bSlaveInterface0 = DYNAMIC */ +}; + +/* full speed support: */ + +static struct usb_endpoint_descriptor acm_fs_notify_desc __initdata = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_INT, + .wMaxPacketSize = __constant_cpu_to_le16(GS_NOTIFY_MAXPACKET), + .bInterval = 1 << GS_LOG2_NOTIFY_INTERVAL, +}; + +static struct usb_endpoint_descriptor acm_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 acm_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 *acm_fs_function[] __initdata = { + (struct usb_descriptor_header *) &acm_control_interface_desc, + (struct usb_descriptor_header *) &acm_header_desc, + (struct usb_descriptor_header *) &acm_call_mgmt_descriptor, + (struct usb_descriptor_header *) &acm_descriptor, + (struct usb_descriptor_header *) &acm_union_desc, + (struct usb_descriptor_header *) &acm_fs_notify_desc, + (struct usb_descriptor_header *) &acm_data_interface_desc, + (struct usb_descriptor_header *) &acm_fs_in_desc, + (struct usb_descriptor_header *) &acm_fs_out_desc, + NULL, +}; + +/* high speed support: */ + +static struct usb_endpoint_descriptor acm_hs_notify_desc __initdata = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_INT, + .wMaxPacketSize = __constant_cpu_to_le16(GS_NOTIFY_MAXPACKET), + .bInterval = GS_LOG2_NOTIFY_INTERVAL+4, +}; + +static struct usb_endpoint_descriptor acm_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 acm_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 *acm_hs_function[] __initdata = { + (struct usb_descriptor_header *) &acm_control_interface_desc, + (struct usb_descriptor_header *) &acm_header_desc, + (struct usb_descriptor_header *) &acm_call_mgmt_descriptor, + (struct usb_descriptor_header *) &acm_descriptor, + (struct usb_descriptor_header *) &acm_union_desc, + (struct usb_descriptor_header *) &acm_hs_notify_desc, + (struct usb_descriptor_header *) &acm_data_interface_desc, + (struct usb_descriptor_header *) &acm_hs_in_desc, + (struct usb_descriptor_header *) &acm_hs_out_desc, + NULL, +}; + +/* string descriptors: */ + +#define ACM_CTRL_IDX 0 +#define ACM_DATA_IDX 1 + +/* static strings, in UTF-8 */ +static struct usb_string acm_string_defs[] = { + [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)", + [ACM_DATA_IDX].s = "CDC ACM Data", + { /* ZEROES END LIST */ }, +}; + +static struct usb_gadget_strings acm_string_table = { + .language = 0x0409, /* en-us */ + .strings = acm_string_defs, +}; + +static struct usb_gadget_strings *acm_strings[] = { + &acm_string_table, + NULL, +}; + +/*-------------------------------------------------------------------------*/ + +/* ACM control ... data handling is delegated to tty library code. + * The main task of this function is to activate and deactivate + * that code based on device state; track parameters like line + * speed, handshake state, and so on; and issue notifications. + */ + +static void acm_complete_set_line_coding(struct usb_ep *ep, + struct usb_request *req) +{ + struct f_acm *acm = ep->driver_data; + struct usb_composite_dev *cdev = acm->port.func.config->cdev; + + if (req->status != 0) { + DBG(cdev, "acm ttyGS%d completion, err %d\n", + acm->port_num, req->status); + return; + } + + /* normal completion */ + if (req->actual != sizeof(acm->port_line_coding)) { + DBG(cdev, "acm ttyGS%d short resp, len %d\n", + acm->port_num, req->actual); + usb_ep_set_halt(ep); + } else { + struct usb_cdc_line_coding *value = req->buf; + + /* REVISIT: we currently just remember this data. + * If we change that, (a) validate it first, then + * (b) update whatever hardware needs updating, + * (c) worry about locking. This is information on + * the order of 9600-8-N-1 ... most of which means + * nothing unless we control a real RS232 line. + */ + acm->port_line_coding = *value; + } +} + +static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) +{ + struct f_acm *acm = func_to_acm(f); + struct usb_composite_dev *cdev = f->config->cdev; + struct usb_request *req = cdev->req; + int value = -EOPNOTSUPP; + u16 w_index = le16_to_cpu(ctrl->wIndex); + u16 w_value = le16_to_cpu(ctrl->wValue); + u16 w_length = le16_to_cpu(ctrl->wLength); + + /* composite driver infrastructure handles everything except + * CDC class messages; interface activation uses set_alt(). + */ + switch ((ctrl->bRequestType << 8) | ctrl->bRequest) { + + /* SET_LINE_CODING ... just read and save what the host sends */ + case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) + | USB_CDC_REQ_SET_LINE_CODING: + if (w_length != sizeof(struct usb_cdc_line_coding) + || w_index != acm->ctrl_id) + goto invalid; + + value = w_length; + cdev->gadget->ep0->driver_data = acm; + req->complete = acm_complete_set_line_coding; + break; + + /* GET_LINE_CODING ... return what host sent, or initial value */ + case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) + | USB_CDC_REQ_GET_LINE_CODING: + if (w_index != acm->ctrl_id) + goto invalid; + + value = min_t(unsigned, w_length, + sizeof(struct usb_cdc_line_coding)); + memcpy(req->buf, &acm->port_line_coding, value); + break; + + /* SET_CONTROL_LINE_STATE ... save what the host sent */ + case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) + | USB_CDC_REQ_SET_CONTROL_LINE_STATE: + if (w_index != acm->ctrl_id) + goto invalid; + + value = 0; + + /* FIXME we should not allow data to flow until the + * host sets the RS232_DTR bit; and when it clears + * that bit, we should return to that no-flow state. + */ + acm->port_handshake_bits = w_value; + break; + + default: +invalid: + VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n", + ctrl->bRequestType, ctrl->bRequest, + w_value, w_index, w_length); + } + + /* respond with data transfer or status phase? */ + if (value >= 0) { + DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n", + acm->port_num, ctrl->bRequestType, ctrl->bRequest, + w_value, w_index, w_length); + req->zero = 0; + req->length = value; + value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); + if (value < 0) + ERROR(cdev, "acm response on ttyGS%d, err %d\n", + acm->port_num, value); + } + + /* device either stalls (value < 0) or reports success */ + return value; +} + +static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt) +{ + struct f_acm *acm = func_to_acm(f); + struct usb_composite_dev *cdev = f->config->cdev; + + /* we know alt == 0, so this is an activation or a reset */ + + if (intf == acm->ctrl_id) { + /* REVISIT this may need more work when we start to + * send notifications ... + */ + if (acm->notify->driver_data) { + VDBG(cdev, "reset acm control interface %d\n", intf); + usb_ep_disable(acm->notify); + } else { + VDBG(cdev, "init acm ctrl interface %d\n", intf); + acm->notify_desc = ep_choose(cdev->gadget, + acm->hs.notify, + acm->fs.notify); + } + usb_ep_enable(acm->notify, acm->notify_desc); + acm->notify->driver_data = acm; + + } else if (intf == acm->data_id) { + if (acm->port.in->driver_data) { + DBG(cdev, "reset acm ttyGS%d\n", acm->port_num); + gserial_disconnect(&acm->port); + } else { + DBG(cdev, "activate acm ttyGS%d\n", acm->port_num); + acm->port.in_desc = ep_choose(cdev->gadget, + acm->hs.in, acm->fs.in); + acm->port.out_desc = ep_choose(cdev->gadget, + acm->hs.out, acm->fs.out); + } + gserial_connect(&acm->port, acm->port_num); + + } else + return -EINVAL; + + return 0; +} + +static void acm_disable(struct usb_function *f) +{ + struct f_acm *acm = func_to_acm(f); + struct usb_composite_dev *cdev = f->config->cdev; + + DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num); + gserial_disconnect(&acm->port); + usb_ep_disable(acm->notify); + acm->notify->driver_data = NULL; +} + +/*-------------------------------------------------------------------------*/ + +/* ACM function driver setup/binding */ +static int __init +acm_bind(struct usb_configuration *c, struct usb_function *f) +{ + struct usb_composite_dev *cdev = c->cdev; + struct f_acm *acm = func_to_acm(f); + int status; + struct usb_ep *ep; + + /* allocate instance-specific interface IDs, and patch descriptors */ + status = usb_interface_id(c, f); + if (status < 0) + goto fail; + acm->ctrl_id = status; + + acm_control_interface_desc.bInterfaceNumber = status; + acm_union_desc .bMasterInterface0 = status; + + status = usb_interface_id(c, f); + if (status < 0) + goto fail; + acm->data_id = status; + + acm_data_interface_desc.bInterfaceNumber = status; + acm_union_desc.bSlaveInterface0 = status; + acm_call_mgmt_descriptor.bDataInterface = status; + + status = -ENODEV; + + /* allocate instance-specific endpoints */ + ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc); + if (!ep) + goto fail; + acm->port.in = ep; + ep->driver_data = cdev; /* claim */ + + ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc); + if (!ep) + goto fail; + acm->port.out = ep; + ep->driver_data = cdev; /* claim */ + + ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc); + if (!ep) + goto fail; + acm->notify = ep; + ep->driver_data = cdev; /* claim */ + + /* copy descriptors, and track endpoint copies */ + f->descriptors = usb_copy_descriptors(acm_fs_function); + + acm->fs.in = usb_find_endpoint(acm_fs_function, + f->descriptors, &acm_fs_in_desc); + acm->fs.out = usb_find_endpoint(acm_fs_function, + f->descriptors, &acm_fs_out_desc); + acm->fs.notify = usb_find_endpoint(acm_fs_function, + f->descriptors, &acm_fs_notify_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)) { + acm_hs_in_desc.bEndpointAddress = + acm_fs_in_desc.bEndpointAddress; + acm_hs_out_desc.bEndpointAddress = + acm_fs_out_desc.bEndpointAddress; + acm_hs_notify_desc.bEndpointAddress = + acm_fs_notify_desc.bEndpointAddress; + + /* copy descriptors, and track endpoint copies */ + f->hs_descriptors = usb_copy_descriptors(acm_hs_function); + + acm->hs.in = usb_find_endpoint(acm_hs_function, + f->hs_descriptors, &acm_hs_in_desc); + acm->hs.out = usb_find_endpoint(acm_hs_function, + f->hs_descriptors, &acm_hs_out_desc); + acm->hs.notify = usb_find_endpoint(acm_hs_function, + f->hs_descriptors, &acm_hs_notify_desc); + } + + /* FIXME provide a callback for triggering notifications */ + + DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n", + acm->port_num, + gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full", + acm->port.in->name, acm->port.out->name, + acm->notify->name); + return 0; + +fail: + /* we might as well release our claims on endpoints */ + if (acm->notify) + acm->notify->driver_data = NULL; + if (acm->port.out) + acm->port.out->driver_data = NULL; + if (acm->port.in) + acm->port.in->driver_data = NULL; + + ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status); + + return status; +} + +static void +acm_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_acm(f)); +} + +/* Some controllers can't support CDC ACM ... */ +static inline bool can_support_cdc(struct usb_configuration *c) +{ + /* SH3 doesn't support multiple interfaces */ + if (gadget_is_sh(c->cdev->gadget)) + return false; + + /* sa1100 doesn't have a third interrupt endpoint */ + if (gadget_is_sa1100(c->cdev->gadget)) + return false; + + /* everything else is *probably* fine ... */ + return true; +} + +/** + * acm_bind_config - add a CDC ACM function to a configuration + * @c: the configuration to support the CDC ACM 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 acm_bind_config(struct usb_configuration *c, u8 port_num) +{ + struct f_acm *acm; + int status; + + if (!can_support_cdc(c)) + return -EINVAL; + + /* REVISIT might want instance-specific strings to help + * distinguish instances ... + */ + + /* maybe allocate device-global string IDs, and patch descriptors */ + if (acm_string_defs[ACM_CTRL_IDX].id == 0) { + status = usb_string_id(c->cdev); + if (status < 0) + return status; + acm_string_defs[ACM_CTRL_IDX].id = status; + + acm_control_interface_desc.iInterface = status; + + status = usb_string_id(c->cdev); + if (status < 0) + return status; + acm_string_defs[ACM_DATA_IDX].id = status; + + acm_data_interface_desc.iInterface = status; + } + + /* allocate and initialize one new instance */ + acm = kzalloc(sizeof *acm, GFP_KERNEL); + if (!acm) + return -ENOMEM; + + acm->port_num = port_num; + + acm->port.func.name = "acm"; + acm->port.func.strings = acm_strings; + /* descriptors are per-instance copies */ + acm->port.func.bind = acm_bind; + acm->port.func.unbind = acm_unbind; + acm->port.func.set_alt = acm_set_alt; + acm->port.func.setup = acm_setup; + acm->port.func.disable = acm_disable; + + status = usb_add_function(c, &acm->port.func); + if (status) + kfree(acm); + return status; +} |