usb: gadget: f_ncm: convert to new function interface with backward compatibility

Converting ncm to the new function interface requires converting
the USB ncm's function code and its users.

This patch converts the f_ncm.c to the new function interface.

The file is now compiled into a separate usb_f_ncm.ko module.

The old function interface is provided by means of a preprocessor
conditional directives. After all users are converted, the old interface
can be removed.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

5 files changed, 194 insertions, 35 deletions

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 5345b6895220..127292ffb4d9 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -511,6 +511,9 @@ config USB_F_SERIAL
 config USB_F_OBEX
         tristate
 
+config USB_F_NCM
+        tristate
+
 choice
         tristate "USB Gadget Drivers"
         default USB_ETH
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index 7a0463ef3684..34b117eec36e 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -48,6 +48,8 @@ obj-$(CONFIG_USB_F_OBEX)	+= usb_f_obex.o
 obj-$(CONFIG_USB_U_ETHER)       += u_ether.o
 u_rndis-y                       := rndis.o
 obj-$(CONFIG_USB_U_RNDIS)       += u_rndis.o
+usb_f_ncm-y                     := f_ncm.o
+obj-$(CONFIG_USB_F_NCM)         += usb_f_ncm.o
 
 #
 # USB gadget drivers
diff --git a/drivers/usb/gadget/f_ncm.c b/drivers/usb/gadget/f_ncm.c
index ee19bc8d0040..722ca1b0dda0 100644
--- a/drivers/usb/gadget/f_ncm.c
+++ b/drivers/usb/gadget/f_ncm.c
@@ -16,6 +16,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/device.h>
 #include <linux/etherdevice.h>
 #include <linux/crc32.h>
@@ -23,6 +24,7 @@
 #include <linux/usb/cdc.h>
 
 #include "u_ether.h"
+#include "u_ncm.h"
 
 /*
  * This function is a "CDC Network Control Model" (CDC NCM) Ethernet link.
@@ -125,7 +127,7 @@ static struct usb_cdc_ncm_ntb_parameters ntb_parameters = {
 #define NCM_STATUS_INTERVAL_MS          32
 #define NCM_STATUS_BYTECOUNT            16      /* 8 byte header + data */
 
-static struct usb_interface_assoc_descriptor ncm_iad_desc __initdata = {
+static struct usb_interface_assoc_descriptor ncm_iad_desc = {
         .bLength =              sizeof ncm_iad_desc,
         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 
@@ -139,7 +141,7 @@ static struct usb_interface_assoc_descriptor ncm_iad_desc __initdata = {
 
 /* interface descriptor: */
 
-static struct usb_interface_descriptor ncm_control_intf __initdata = {
+static struct usb_interface_descriptor ncm_control_intf = {
         .bLength =              sizeof ncm_control_intf,
         .bDescriptorType =      USB_DT_INTERFACE,
 
@@ -151,7 +153,7 @@ static struct usb_interface_descriptor ncm_control_intf __initdata = {
         /* .iInterface = DYNAMIC */
 };
 
-static struct usb_cdc_header_desc ncm_header_desc __initdata = {
+static struct usb_cdc_header_desc ncm_header_desc = {
         .bLength =              sizeof ncm_header_desc,
         .bDescriptorType =      USB_DT_CS_INTERFACE,
         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
@@ -159,7 +161,7 @@ static struct usb_cdc_header_desc ncm_header_desc __initdata = {
         .bcdCDC =               cpu_to_le16(0x0110),
 };
 
-static struct usb_cdc_union_desc ncm_union_desc __initdata = {
+static struct usb_cdc_union_desc ncm_union_desc = {
         .bLength =              sizeof(ncm_union_desc),
         .bDescriptorType =      USB_DT_CS_INTERFACE,
         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
@@ -167,7 +169,7 @@ static struct usb_cdc_union_desc ncm_union_desc __initdata = {
         /* .bSlaveInterface0 =  DYNAMIC */
 };
 
-static struct usb_cdc_ether_desc ecm_desc __initdata = {
+static struct usb_cdc_ether_desc ecm_desc = {
         .bLength =              sizeof ecm_desc,
         .bDescriptorType =      USB_DT_CS_INTERFACE,
         .bDescriptorSubType =   USB_CDC_ETHERNET_TYPE,
@@ -182,7 +184,7 @@ static struct usb_cdc_ether_desc ecm_desc __initdata = {
 
 #define NCAPS   (USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE)
 
-static struct usb_cdc_ncm_desc ncm_desc __initdata = {
+static struct usb_cdc_ncm_desc ncm_desc = {
         .bLength =              sizeof ncm_desc,
         .bDescriptorType =      USB_DT_CS_INTERFACE,
         .bDescriptorSubType =   USB_CDC_NCM_TYPE,
@@ -194,7 +196,7 @@ static struct usb_cdc_ncm_desc ncm_desc __initdata = {
 
 /* the default data interface has no endpoints ... */
 
-static struct usb_interface_descriptor ncm_data_nop_intf __initdata = {
+static struct usb_interface_descriptor ncm_data_nop_intf = {
         .bLength =              sizeof ncm_data_nop_intf,
         .bDescriptorType =      USB_DT_INTERFACE,
 
@@ -209,7 +211,7 @@ static struct usb_interface_descriptor ncm_data_nop_intf __initdata = {
 
 /* ... but the "real" data interface has two bulk endpoints */
 
-static struct usb_interface_descriptor ncm_data_intf __initdata = {
+static struct usb_interface_descriptor ncm_data_intf = {
         .bLength =              sizeof ncm_data_intf,
         .bDescriptorType =      USB_DT_INTERFACE,
 
@@ -224,7 +226,7 @@ static struct usb_interface_descriptor ncm_data_intf __initdata = {
 
 /* full speed support: */
 
-static struct usb_endpoint_descriptor fs_ncm_notify_desc __initdata = {
+static struct usb_endpoint_descriptor fs_ncm_notify_desc = {
         .bLength =              USB_DT_ENDPOINT_SIZE,
         .bDescriptorType =      USB_DT_ENDPOINT,
 
@@ -234,7 +236,7 @@ static struct usb_endpoint_descriptor fs_ncm_notify_desc __initdata = {
         .bInterval =            NCM_STATUS_INTERVAL_MS,
 };
 
-static struct usb_endpoint_descriptor fs_ncm_in_desc __initdata = {
+static struct usb_endpoint_descriptor fs_ncm_in_desc = {
         .bLength =              USB_DT_ENDPOINT_SIZE,
         .bDescriptorType =      USB_DT_ENDPOINT,
 
@@ -242,7 +244,7 @@ static struct usb_endpoint_descriptor fs_ncm_in_desc __initdata = {
         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 };
 
-static struct usb_endpoint_descriptor fs_ncm_out_desc __initdata = {
+static struct usb_endpoint_descriptor fs_ncm_out_desc = {
         .bLength =              USB_DT_ENDPOINT_SIZE,
         .bDescriptorType =      USB_DT_ENDPOINT,
 
@@ -250,7 +252,7 @@ static struct usb_endpoint_descriptor fs_ncm_out_desc __initdata = {
         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 };
 
-static struct usb_descriptor_header *ncm_fs_function[] __initdata = {
+static struct usb_descriptor_header *ncm_fs_function[] = {
         (struct usb_descriptor_header *) &ncm_iad_desc,
         /* CDC NCM control descriptors */
         (struct usb_descriptor_header *) &ncm_control_intf,
@@ -269,7 +271,7 @@ static struct usb_descriptor_header *ncm_fs_function[] __initdata = {
 
 /* high speed support: */
 
-static struct usb_endpoint_descriptor hs_ncm_notify_desc __initdata = {
+static struct usb_endpoint_descriptor hs_ncm_notify_desc = {
         .bLength =              USB_DT_ENDPOINT_SIZE,
         .bDescriptorType =      USB_DT_ENDPOINT,
 
@@ -278,7 +280,7 @@ static struct usb_endpoint_descriptor hs_ncm_notify_desc __initdata = {
         .wMaxPacketSize =       cpu_to_le16(NCM_STATUS_BYTECOUNT),
         .bInterval =            USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS),
 };
-static struct usb_endpoint_descriptor hs_ncm_in_desc __initdata = {
+static struct usb_endpoint_descriptor hs_ncm_in_desc = {
         .bLength =              USB_DT_ENDPOINT_SIZE,
         .bDescriptorType =      USB_DT_ENDPOINT,
 
@@ -287,7 +289,7 @@ static struct usb_endpoint_descriptor hs_ncm_in_desc __initdata = {
         .wMaxPacketSize =       cpu_to_le16(512),
 };
 
-static struct usb_endpoint_descriptor hs_ncm_out_desc __initdata = {
+static struct usb_endpoint_descriptor hs_ncm_out_desc = {
         .bLength =              USB_DT_ENDPOINT_SIZE,
         .bDescriptorType =      USB_DT_ENDPOINT,
 
@@ -296,7 +298,7 @@ static struct usb_endpoint_descriptor hs_ncm_out_desc __initdata = {
         .wMaxPacketSize =       cpu_to_le16(512),
 };
 
-static struct usb_descriptor_header *ncm_hs_function[] __initdata = {
+static struct usb_descriptor_header *ncm_hs_function[] = {
         (struct usb_descriptor_header *) &ncm_iad_desc,
         /* CDC NCM control descriptors */
         (struct usb_descriptor_header *) &ncm_control_intf,
@@ -1152,14 +1154,50 @@ static void ncm_close(struct gether *geth)
 
 /* ethernet function driver setup/binding */
 
-static int __init
-ncm_bind(struct usb_configuration *c, struct usb_function *f)
+static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
 {
         struct usb_composite_dev *cdev = c->cdev;
         struct f_ncm            *ncm = func_to_ncm(f);
         int                     status;
         struct usb_ep           *ep;
 
+#ifndef USB_FNCM_INCLUDED
+        struct f_ncm_opts       *ncm_opts;
+
+        if (!can_support_ecm(cdev->gadget))
+                return -EINVAL;
+
+        ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
+        /*
+         * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
+         * configurations are bound in sequence with list_for_each_entry,
+         * in each configuration its functions are bound in sequence
+         * with list_for_each_entry, so we assume no race condition
+         * with regard to ncm_opts->bound access
+         */
+        if (!ncm_opts->bound) {
+                gether_set_gadget(ncm_opts->net, cdev->gadget);
+                status = gether_register_netdev(ncm_opts->net);
+                if (status)
+                        return status;
+                ncm_opts->bound = true;
+        }
+#endif
+        if (ncm_string_defs[0].id == 0) {
+                status = usb_string_ids_tab(c->cdev, ncm_string_defs);
+                if (status < 0)
+                        return status;
+                ncm_control_intf.iInterface =
+                        ncm_string_defs[STRING_CTRL_IDX].id;
+
+                status = ncm_string_defs[STRING_DATA_IDX].id;
+                ncm_data_nop_intf.iInterface = status;
+                ncm_data_intf.iInterface = status;
+
+                ecm_desc.iMACAddress = ncm_string_defs[STRING_MAC_IDX].id;
+                ncm_iad_desc.iFunction = ncm_string_defs[STRING_IAD_IDX].id;
+        }
+
         /* allocate instance-specific interface IDs */
         status = usb_interface_id(c, f);
         if (status < 0)
@@ -1259,8 +1297,10 @@ fail:
         return status;
 }
 
+#ifdef USB_FNCM_INCLUDED
+
 static void
-ncm_unbind(struct usb_configuration *c, struct usb_function *f)
+ncm_old_unbind(struct usb_configuration *c, struct usb_function *f)
 {
         struct f_ncm            *ncm = func_to_ncm(f);
 
@@ -1296,21 +1336,6 @@ int __init ncm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
         if (!can_support_ecm(c->cdev->gadget) || !ethaddr)
                 return -EINVAL;
 
-        if (ncm_string_defs[0].id == 0) {
-                status = usb_string_ids_tab(c->cdev, ncm_string_defs);
-                if (status < 0)
-                        return status;
-                ncm_control_intf.iInterface =
-                        ncm_string_defs[STRING_CTRL_IDX].id;
-
-                status = ncm_string_defs[STRING_DATA_IDX].id;
-                ncm_data_nop_intf.iInterface = status;
-                ncm_data_intf.iInterface = status;
-
-                ecm_desc.iMACAddress = ncm_string_defs[STRING_MAC_IDX].id;
-                ncm_iad_desc.iFunction = ncm_string_defs[STRING_IAD_IDX].id;
-        }
-
         /* allocate and initialize one new instance */
         ncm = kzalloc(sizeof *ncm, GFP_KERNEL);
         if (!ncm)
@@ -1329,7 +1354,7 @@ int __init ncm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
         ncm->port.func.strings = ncm_strings;
         /* descriptors are per-instance copies */
         ncm->port.func.bind = ncm_bind;
-        ncm->port.func.unbind = ncm_unbind;
+        ncm->port.func.unbind = ncm_old_unbind;
         ncm->port.func.set_alt = ncm_set_alt;
         ncm->port.func.get_alt = ncm_get_alt;
         ncm->port.func.setup = ncm_setup;
@@ -1343,3 +1368,104 @@ int __init ncm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
                 kfree(ncm);
         return status;
 }
+
+#else
+
+static void ncm_free_inst(struct usb_function_instance *f)
+{
+        struct f_ncm_opts *opts;
+
+        opts = container_of(f, struct f_ncm_opts, func_inst);
+        if (opts->bound)
+                gether_cleanup(netdev_priv(opts->net));
+        else
+                free_netdev(opts->net);
+        kfree(opts);
+}
+
+static struct usb_function_instance *ncm_alloc_inst(void)
+{
+        struct f_ncm_opts *opts;
+
+        opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+        if (!opts)
+                return ERR_PTR(-ENOMEM);
+        opts->func_inst.free_func_inst = ncm_free_inst;
+        opts->net = gether_setup_default();
+        if (IS_ERR(opts->net))
+                return ERR_PTR(PTR_ERR(opts->net));
+
+        return &opts->func_inst;
+}
+
+static void ncm_free(struct usb_function *f)
+{
+        struct f_ncm *ncm;
+
+        ncm = func_to_ncm(f);
+        kfree(ncm);
+}
+
+static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+        struct f_ncm *ncm = func_to_ncm(f);
+
+        DBG(c->cdev, "ncm unbind\n");
+
+        ncm_string_defs[0].id = 0;
+        usb_free_all_descriptors(f);
+
+        kfree(ncm->notify_req->buf);
+        usb_ep_free_request(ncm->notify, ncm->notify_req);
+}
+
+struct usb_function *ncm_alloc(struct usb_function_instance *fi)
+{
+        struct f_ncm            *ncm;
+        struct f_ncm_opts       *opts;
+        int status;
+
+        /* allocate and initialize one new instance */
+        ncm = kzalloc(sizeof(*ncm), GFP_KERNEL);
+        if (!ncm)
+                return ERR_PTR(-ENOMEM);
+
+        opts = container_of(fi, struct f_ncm_opts, func_inst);
+
+        /* export host's Ethernet address in CDC format */
+        status = gether_get_host_addr_cdc(opts->net, ncm->ethaddr,
+                                      sizeof(ncm->ethaddr));
+        if (status < 12) { /* strlen("01234567890a") */
+                kfree(ncm);
+                return ERR_PTR(-EINVAL);
+        }
+        ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr;
+
+        spin_lock_init(&ncm->lock);
+        ncm_reset_values(ncm);
+        ncm->port.ioport = netdev_priv(opts->net);
+        ncm->port.is_fixed = true;
+
+        ncm->port.func.name = "cdc_network";
+        ncm->port.func.strings = ncm_strings;
+        /* descriptors are per-instance copies */
+        ncm->port.func.bind = ncm_bind;
+        ncm->port.func.unbind = ncm_unbind;
+        ncm->port.func.set_alt = ncm_set_alt;
+        ncm->port.func.get_alt = ncm_get_alt;
+        ncm->port.func.setup = ncm_setup;
+        ncm->port.func.disable = ncm_disable;
+        ncm->port.func.free_func = ncm_free;
+
+        ncm->port.wrap = ncm_wrap_ntb;
+        ncm->port.unwrap = ncm_unwrap_ntb;
+
+        return &ncm->port.func;
+}
+
+DECLARE_USB_FUNCTION_INIT(ncm, ncm_alloc_inst, ncm_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yauheni Kaliuta");
+
+#endif
+
diff --git a/drivers/usb/gadget/ncm.c b/drivers/usb/gadget/ncm.c
index e411135b21e5..e2f97eecd7ce 100644
--- a/drivers/usb/gadget/ncm.c
+++ b/drivers/usb/gadget/ncm.c
@@ -36,6 +36,7 @@
  * the runtime footprint, and giving us at least some parts of what
  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  */
+#define USB_FNCM_INCLUDED
 #include "f_ncm.c"
 
 /*-------------------------------------------------------------------------*/
diff --git a/drivers/usb/gadget/u_ncm.h b/drivers/usb/gadget/u_ncm.h
new file mode 100644
index 000000000000..1e22b5fa844b
--- /dev/null
+++ b/drivers/usb/gadget/u_ncm.h
@@ -0,0 +1,27 @@
+/*
+ * u_ncm.h
+ *
+ * Utility definitions for the ncm function
+ *
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ *              http://www.samsung.com
+ *
+ * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef U_NCM_H
+#define U_NCM_H
+
+#include <linux/usb/composite.h>
+
+struct f_ncm_opts {
+        struct usb_function_instance    func_inst;
+        struct net_device               *net;
+        bool                            bound;
+};
+
+#endif /* U_NCM_H */