USB: gadget: g_multi: code clean up and refactoring

The Multifunction Composite Gadget have been cleaned up
and refactored so hopefully it looks prettier and works
at least as good as before changes.

A Kconfig has also been fixed to make it impossible to build
FunctionFS gadget with no configurations.  With this patch, if
RNDIS is not chosen by the user CDC is force-selected.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 147 insertions, 116 deletions

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 591ae9fde199..027f61b1f3d8 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -863,6 +863,7 @@ config USB_G_NOKIA
 config USB_G_MULTI
         tristate "Multifunction Composite Gadget (EXPERIMENTAL)"
         depends on BLOCK && NET
+        select USB_G_MULTI_CDC if !USB_G_MULTI_RNDIS
         help
           The Multifunction Composite Gadget provides Ethernet (RNDIS
           and/or CDC Ethernet), mass storage and ACM serial link
diff --git a/drivers/usb/gadget/multi.c b/drivers/usb/gadget/multi.c
index d3d314033022..795d76232167 100644
--- a/drivers/usb/gadget/multi.c
+++ b/drivers/usb/gadget/multi.c
@@ -24,6 +24,7 @@
 
 #include <linux/kernel.h>
 #include <linux/utsname.h>
+#include <linux/module.h>
 
 
 #if defined USB_ETH_RNDIS
@@ -35,14 +36,13 @@
 
 
 #define DRIVER_DESC             "Multifunction Composite Gadget"
-#define DRIVER_VERSION          "2009/07/21"
 
-/*-------------------------------------------------------------------------*/
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Michal Nazarewicz");
+MODULE_LICENSE("GPL");
 
-#define MULTI_VENDOR_NUM        0x0525  /* XXX NetChip */
-#define MULTI_PRODUCT_NUM       0xa4ab  /* XXX */
 
-/*-------------------------------------------------------------------------*/
+/***************************** All the files... *****************************/
 
 /*
  * kbuild is not very cooperative with respect to linking separately
@@ -57,6 +57,8 @@
 #include "config.c"
 #include "epautoconf.c"
 
+#include "f_mass_storage.c"
+
 #include "u_serial.c"
 #include "f_acm.c"
 
@@ -68,13 +70,24 @@
 #endif
 #include "u_ether.c"
 
-#undef DBG     /* u_ether.c has broken idea about macros */
-#undef VDBG    /* so clean up after it */
-#undef ERROR
-#undef INFO
-#include "f_mass_storage.c"
 
-/*-------------------------------------------------------------------------*/
+
+/***************************** Device Descriptor ****************************/
+
+#define MULTI_VENDOR_NUM        0x0525  /* XXX NetChip */
+#define MULTI_PRODUCT_NUM       0xa4ab  /* XXX */
+
+
+enum {
+        __MULTI_NO_CONFIG,
+#ifdef CONFIG_USB_G_MULTI_RNDIS
+        MULTI_RNDIS_CONFIG_NUM,
+#endif
+#ifdef CONFIG_USB_G_MULTI_CDC
+        MULTI_CDC_CONFIG_NUM,
+#endif
+};
+
 
 static struct usb_device_descriptor device_desc = {
         .bLength =              sizeof device_desc,
@@ -82,80 +95,82 @@ static struct usb_device_descriptor device_desc = {
 
         .bcdUSB =               cpu_to_le16(0x0200),
 
-        /* .bDeviceClass =              USB_CLASS_COMM, */
-        /* .bDeviceSubClass =   0, */
-        /* .bDeviceProtocol =   0, */
-        .bDeviceClass =         0xEF,
+        .bDeviceClass =         USB_CLASS_MISC /* 0xEF */,
         .bDeviceSubClass =      2,
         .bDeviceProtocol =      1,
-        /* .bMaxPacketSize0 = f(hardware) */
 
         /* Vendor and product id can be overridden by module parameters.  */
         .idVendor =             cpu_to_le16(MULTI_VENDOR_NUM),
         .idProduct =            cpu_to_le16(MULTI_PRODUCT_NUM),
-        /* .bcdDevice = f(hardware) */
-        /* .iManufacturer = DYNAMIC */
-        /* .iProduct = DYNAMIC */
-        /* NO SERIAL NUMBER */
-        .bNumConfigurations =   1,
 };
 
-static struct usb_otg_descriptor otg_descriptor = {
-        .bLength =              sizeof otg_descriptor,
-        .bDescriptorType =      USB_DT_OTG,
-
-        /* REVISIT SRP-only hardware is possible, although
-         * it would not be called "OTG" ...
-         */
-        .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
-};
 
 static const struct usb_descriptor_header *otg_desc[] = {
-        (struct usb_descriptor_header *) &otg_descriptor,
+        (struct usb_descriptor_header *) &(struct usb_otg_descriptor){
+                .bLength =              sizeof(struct usb_otg_descriptor),
+                .bDescriptorType =      USB_DT_OTG,
+
+                /*
+                 * REVISIT SRP-only hardware is possible, although
+                 * it would not be called "OTG" ...
+                 */
+                .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
+        },
         NULL,
 };
 
 
-/* string IDs are assigned dynamically */
-
-#define STRING_MANUFACTURER_IDX         0
-#define STRING_PRODUCT_IDX              1
+enum {
+        MULTI_STRING_MANUFACTURER_IDX,
+        MULTI_STRING_PRODUCT_IDX,
+#ifdef CONFIG_USB_G_MULTI_RNDIS
+        MULTI_STRING_RNDIS_CONFIG_IDX,
+#endif
+#ifdef CONFIG_USB_G_MULTI_CDC
+        MULTI_STRING_CDC_CONFIG_IDX,
+#endif
+};
 
 static char manufacturer[50];
 
 static struct usb_string strings_dev[] = {
-        [STRING_MANUFACTURER_IDX].s = manufacturer,
-        [STRING_PRODUCT_IDX].s = DRIVER_DESC,
+        [MULTI_STRING_MANUFACTURER_IDX].s = manufacturer,
+        [MULTI_STRING_PRODUCT_IDX].s      = DRIVER_DESC,
+#ifdef CONFIG_USB_G_MULTI_RNDIS
+        [MULTI_STRING_RNDIS_CONFIG_IDX].s = "Multifunction with RNDIS",
+#endif
+#ifdef CONFIG_USB_G_MULTI_CDC
+        [MULTI_STRING_CDC_CONFIG_IDX].s   = "Multifunction with CDC ECM",
+#endif
         {  } /* end of list */
 };
 
-static struct usb_gadget_strings stringtab_dev = {
-        .language       = 0x0409,       /* en-us */
-        .strings        = strings_dev,
-};
-
 static struct usb_gadget_strings *dev_strings[] = {
-        &stringtab_dev,
+        &(struct usb_gadget_strings){
+                .language       = 0x0409,       /* en-us */
+                .strings        = strings_dev,
+        },
         NULL,
 };
 
-static u8 hostaddr[ETH_ALEN];
 
 
 
 /****************************** Configurations ******************************/
 
-static struct fsg_module_parameters mod_data = {
-        .stall = 1
-};
-FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
+static struct fsg_module_parameters fsg_mod_data = { .stall = 1 };
+FSG_MODULE_PARAMETERS(/* no prefix */, fsg_mod_data);
+
+static struct fsg_common fsg_common;
+
+static u8 hostaddr[ETH_ALEN];
 
-static struct fsg_common *fsg_common;
 
+/********** RNDIS **********/
 
 #ifdef USB_ETH_RNDIS
 
-static int __init rndis_do_config(struct usb_configuration *c)
+static __ref int rndis_do_config(struct usb_configuration *c)
 {
         int ret;
 
@@ -172,26 +187,42 @@ static int __init rndis_do_config(struct usb_configuration *c)
         if (ret < 0)
                 return ret;
 
-        ret = fsg_bind_config(c->cdev, c, fsg_common);
+        ret = fsg_bind_config(c->cdev, c, &fsg_common);
         if (ret < 0)
                 return ret;
 
         return 0;
 }
 
-static struct usb_configuration rndis_config_driver = {
-        .label                  = "Multifunction Composite (RNDIS + MS + ACM)",
-        .bind                   = rndis_do_config,
-        .bConfigurationValue    = 2,
-        /* .iConfiguration = DYNAMIC */
-        .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
-};
+static int rndis_config_register(struct usb_composite_dev *cdev)
+{
+        static struct usb_configuration config = {
+                .bind                   = rndis_do_config,
+                .bConfigurationValue    = MULTI_RNDIS_CONFIG_NUM,
+                .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
+        };
+
+        config.label          = strings_dev[MULTI_STRING_RNDIS_CONFIG_IDX].s;
+        config.iConfiguration = strings_dev[MULTI_STRING_RNDIS_CONFIG_IDX].id;
+
+        return usb_add_config(cdev, &config);
+}
+
+#else
+
+static int rndis_config_register(struct usb_composite_dev *cdev)
+{
+        return 0;
+}
 
 #endif
 
+
+/********** CDC ECM **********/
+
 #ifdef CONFIG_USB_G_MULTI_CDC
 
-static int __init cdc_do_config(struct usb_configuration *c)
+static __ref int cdc_do_config(struct usb_configuration *c)
 {
         int ret;
 
@@ -208,20 +239,33 @@ static int __init cdc_do_config(struct usb_configuration *c)
         if (ret < 0)
                 return ret;
 
-        ret = fsg_bind_config(c->cdev, c, fsg_common);
+        ret = fsg_bind_config(c->cdev, c, &fsg_common);
         if (ret < 0)
                 return ret;
 
         return 0;
 }
 
-static struct usb_configuration cdc_config_driver = {
-        .label                  = "Multifunction Composite (CDC + MS + ACM)",
-        .bind                   = cdc_do_config,
-        .bConfigurationValue    = 1,
-        /* .iConfiguration = DYNAMIC */
-        .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
-};
+static int cdc_config_register(struct usb_composite_dev *cdev)
+{
+        static struct usb_configuration config = {
+                .bind                   = cdc_do_config,
+                .bConfigurationValue    = MULTI_CDC_CONFIG_NUM,
+                .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
+        };
+
+        config.label          = strings_dev[MULTI_STRING_CDC_CONFIG_IDX].s;
+        config.iConfiguration = strings_dev[MULTI_STRING_CDC_CONFIG_IDX].id;
+
+        return usb_add_config(cdev, &config);
+}
+
+#else
+
+static int cdc_config_register(struct usb_composite_dev *cdev)
+{
+        return 0;
+}
 
 #endif
 
@@ -230,7 +274,7 @@ static struct usb_configuration cdc_config_driver = {
 /****************************** Gadget Bind ******************************/
 
 
-static int __init multi_bind(struct usb_composite_dev *cdev)
+static int __ref multi_bind(struct usb_composite_dev *cdev)
 {
         struct usb_gadget *gadget = cdev->gadget;
         int status, gcnum;
@@ -252,67 +296,56 @@ static int __init multi_bind(struct usb_composite_dev *cdev)
                 goto fail0;
 
         /* set up mass storage function */
-        fsg_common = fsg_common_from_params(0, cdev, &mod_data);
-        if (IS_ERR(fsg_common)) {
-                status = PTR_ERR(fsg_common);
-                goto fail1;
+        {
+                void *retp;
+                retp = fsg_common_from_params(&fsg_common, cdev, &fsg_mod_data);
+                if (IS_ERR(retp)) {
+                        status = PTR_ERR(retp);
+                        goto fail1;
+                }
         }
 
-
+        /* set bcdDevice */
         gcnum = usb_gadget_controller_number(gadget);
-        if (gcnum >= 0)
+        if (gcnum >= 0) {
                 device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
-        else {
-                /* We assume that can_support_ecm() tells the truth;
-                 * but if the controller isn't recognized at all then
-                 * that assumption is a bit more likely to be wrong.
-                 */
-                WARNING(cdev, "controller '%s' not recognized\n",
-                        gadget->name);
+        } else {
+                WARNING(cdev, "controller '%s' not recognized\n", gadget->name);
                 device_desc.bcdDevice = cpu_to_le16(0x0300 | 0x0099);
         }
 
-
-        /* Allocate string descriptor numbers ... note that string
-         * contents can be overridden by the composite_dev glue.
-         */
-
-        /* device descriptor strings: manufacturer, product */
+        /* allocate string descriptor numbers */
         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
                  init_utsname()->sysname, init_utsname()->release,
                  gadget->name);
-        status = usb_string_id(cdev);
-        if (status < 0)
-                goto fail2;
-        strings_dev[STRING_MANUFACTURER_IDX].id = status;
-        device_desc.iManufacturer = status;
 
-        status = usb_string_id(cdev);
-        if (status < 0)
+        status = usb_string_ids_tab(cdev, strings_dev);
+        if (unlikely(status < 0))
                 goto fail2;
-        strings_dev[STRING_PRODUCT_IDX].id = status;
-        device_desc.iProduct = status;
 
-#ifdef USB_ETH_RNDIS
-        /* register our first configuration */
-        status = usb_add_config(cdev, &rndis_config_driver);
-        if (status < 0)
+        device_desc.iManufacturer =
+                strings_dev[MULTI_STRING_MANUFACTURER_IDX].id;
+        device_desc.iProduct      =
+                strings_dev[MULTI_STRING_PRODUCT_IDX].id;
+
+        /* register configurations */
+        status = rndis_config_register(cdev);
+        if (unlikely(status < 0))
                 goto fail2;
-#endif
 
-#ifdef CONFIG_USB_G_MULTI_CDC
-        /* register our second configuration */
-        status = usb_add_config(cdev, &cdc_config_driver);
-        if (status < 0)
+        status = cdc_config_register(cdev);
+        if (unlikely(status < 0))
                 goto fail2;
-#endif
 
-        dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
-        fsg_common_put(fsg_common);
+        /* we're done */
+        dev_info(&gadget->dev, DRIVER_DESC "\n");
+        fsg_common_put(&fsg_common);
         return 0;
 
+
+        /* error recovery */
 fail2:
-        fsg_common_put(fsg_common);
+        fsg_common_put(&fsg_common);
 fail1:
         gserial_cleanup();
 fail0:
@@ -339,18 +372,15 @@ static struct usb_composite_driver multi_driver = {
         .unbind         = __exit_p(multi_unbind),
 };
 
-MODULE_DESCRIPTION(DRIVER_DESC);
-MODULE_AUTHOR("Michal Nazarewicz");
-MODULE_LICENSE("GPL");
 
-static int __init g_multi_init(void)
+static int __init multi_init(void)
 {
         return usb_composite_register(&multi_driver);
 }
-module_init(g_multi_init);
+module_init(multi_init);
 
-static void __exit g_multi_cleanup(void)
+static void __exit multi_exit(void)
 {
         usb_composite_unregister(&multi_driver);
 }
-module_exit(g_multi_cleanup);
+module_exit(multi_exit);