usb: gadget: f_acm: convert to new function interface with backwards compatibility

This patch converts f_acm into a module which uses the new function
interface. It also converts one of its users that is g_serial to make
use of it. The other users of it (g_nokia for instance) are still using
the old include file system and should not notice the change at all. So
they can be converter later independently.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

9 files changed, 186 insertions, 55 deletions

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 8aefbbddf2a7..b61c72fc305a 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -500,6 +500,9 @@ config USB_LIBCOMPOSITE
         tristate
         depends on USB_GADGET
 
+config USB_F_ACM
+        tristate
+
 config USB_F_SS_LB
         tristate
 
@@ -758,6 +761,7 @@ config USB_GADGET_TARGET
 config USB_G_SERIAL
         tristate "Serial Gadget (with CDC ACM and CDC OBEX support)"
         select USB_U_SERIAL
+        select USB_F_ACM
         select USB_LIBCOMPOSITE
         help
           The Serial Gadget talks to the Linux-USB generic serial driver.
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index b88ee775de6b..97a13c349cc5 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -76,6 +76,7 @@ obj-$(CONFIG_USB_G_ACM_MS)	+= g_acm_ms.o
 obj-$(CONFIG_USB_GADGET_TARGET) += tcm_usb_gadget.o
 
 # USB Functions
+obj-$(CONFIG_USB_F_ACM)         += f_acm.o
 f_ss_lb-y                       := f_loopback.o f_sourcesink.o
 obj-$(CONFIG_USB_F_SS_LB)       += f_ss_lb.o
 obj-$(CONFIG_USB_U_SERIAL)      += u_serial.o
diff --git a/drivers/usb/gadget/acm_ms.c b/drivers/usb/gadget/acm_ms.c
index eb0fbdae5ccb..4105a06582f8 100644
--- a/drivers/usb/gadget/acm_ms.c
+++ b/drivers/usb/gadget/acm_ms.c
@@ -40,7 +40,7 @@
  * 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_FACM_INCLUDED
 #include "f_acm.c"
 #include "f_mass_storage.c"
 
diff --git a/drivers/usb/gadget/cdc2.c b/drivers/usb/gadget/cdc2.c
index 16911a5aeb03..13b17f0b2da1 100644
--- a/drivers/usb/gadget/cdc2.c
+++ b/drivers/usb/gadget/cdc2.c
@@ -42,7 +42,7 @@ USB_GADGET_COMPOSITE_OPTIONS();
  * 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_FACM_INCLUDED
 #include "f_acm.c"
 #include "f_ecm.c"
 #include "u_ether.c"
diff --git a/drivers/usb/gadget/f_acm.c b/drivers/usb/gadget/f_acm.c
index 3178fa70916e..3ea7dc89b43d 100644
--- a/drivers/usb/gadget/f_acm.c
+++ b/drivers/usb/gadget/f_acm.c
@@ -16,7 +16,9 @@
 
 #include <linux/slab.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/device.h>
+#include <linux/err.h>
 
 #include "u_serial.h"
 #include "gadget_chips.h"
@@ -608,6 +610,22 @@ acm_bind(struct usb_configuration *c, struct usb_function *f)
         int                     status;
         struct usb_ep           *ep;
 
+        /* REVISIT might want instance-specific strings to help
+         * distinguish instances ...
+         */
+
+        /* maybe allocate device-global string IDs, and patch descriptors */
+        if (acm_string_defs[0].id == 0) {
+                status = usb_string_ids_tab(c->cdev, acm_string_defs);
+                if (status < 0)
+                        return status;
+                acm_control_interface_desc.iInterface =
+                        acm_string_defs[ACM_CTRL_IDX].id;
+                acm_data_interface_desc.iInterface =
+                        acm_string_defs[ACM_DATA_IDX].id;
+                acm_iad_descriptor.iFunction = acm_string_defs[ACM_IAD_IDX].id;
+        }
+
         /* allocate instance-specific interface IDs, and patch descriptors */
         status = usb_interface_id(c, f);
         if (status < 0)
@@ -700,14 +718,41 @@ fail:
         return status;
 }
 
+static struct f_acm *acm_alloc_basic_func(void)
+{
+        struct f_acm    *acm;
+
+        acm = kzalloc(sizeof(*acm), GFP_KERNEL);
+        if (!acm)
+                return NULL;
+
+        spin_lock_init(&acm->lock);
+
+        acm->port.connect = acm_connect;
+        acm->port.disconnect = acm_disconnect;
+        acm->port.send_break = acm_send_break;
+
+        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.set_alt = acm_set_alt;
+        acm->port.func.setup = acm_setup;
+        acm->port.func.disable = acm_disable;
+
+        return acm;
+}
+
+#ifdef USB_FACM_INCLUDED
 static void
-acm_unbind(struct usb_configuration *c, struct usb_function *f)
+acm_old_unbind(struct usb_configuration *c, struct usb_function *f)
 {
         struct f_acm            *acm = func_to_acm(f);
 
         acm_string_defs[0].id = 0;
         usb_free_all_descriptors(f);
-        gs_free_req(acm->notify, acm->notify_req);
+        if (acm->notify_req)
+                gs_free_req(acm->notify, acm->notify_req);
         kfree(acm);
 }
 
@@ -725,46 +770,74 @@ int acm_bind_config(struct usb_configuration *c, u8 port_num)
         struct f_acm    *acm;
         int             status;
 
-        /* REVISIT might want instance-specific strings to help
-         * distinguish instances ...
-         */
-
-        /* maybe allocate device-global string IDs, and patch descriptors */
-        if (acm_string_defs[0].id == 0) {
-                status = usb_string_ids_tab(c->cdev, acm_string_defs);
-                if (status < 0)
-                        return status;
-                acm_control_interface_desc.iInterface =
-                        acm_string_defs[ACM_CTRL_IDX].id;
-                acm_data_interface_desc.iInterface =
-                        acm_string_defs[ACM_DATA_IDX].id;
-                acm_iad_descriptor.iFunction = acm_string_defs[ACM_IAD_IDX].id;
-        }
-
         /* allocate and initialize one new instance */
-        acm = kzalloc(sizeof *acm, GFP_KERNEL);
+        acm = acm_alloc_basic_func();
         if (!acm)
                 return -ENOMEM;
 
-        spin_lock_init(&acm->lock);
-
         acm->port_num = port_num;
-
-        acm->port.connect = acm_connect;
-        acm->port.disconnect = acm_disconnect;
-        acm->port.send_break = acm_send_break;
-
-        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;
+        acm->port.func.unbind = acm_old_unbind;
 
         status = usb_add_function(c, &acm->port.func);
         if (status)
                 kfree(acm);
         return status;
 }
+
+#else
+
+static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+        struct f_acm            *acm = func_to_acm(f);
+
+        acm_string_defs[0].id = 0;
+        usb_free_all_descriptors(f);
+        if (acm->notify_req)
+                gs_free_req(acm->notify, acm->notify_req);
+}
+
+static void acm_free_func(struct usb_function *f)
+{
+        struct f_acm            *acm = func_to_acm(f);
+
+        kfree(acm);
+}
+
+static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
+{
+        struct f_serial_opts *opts;
+        struct f_acm *acm;
+
+        acm = acm_alloc_basic_func();
+        if (!acm)
+                return ERR_PTR(-ENOMEM);
+
+        opts = container_of(fi, struct f_serial_opts, func_inst);
+        acm->port_num = opts->port_num;
+        acm->port.func.unbind = acm_unbind;
+        acm->port.func.free_func = acm_free_func;
+
+        return &acm->port.func;
+}
+
+static void acm_free_instance(struct usb_function_instance *fi)
+{
+        struct f_serial_opts *opts;
+
+        opts = container_of(fi, struct f_serial_opts, func_inst);
+        kfree(opts);
+}
+
+static struct usb_function_instance *acm_alloc_instance(void)
+{
+        struct f_serial_opts *opts;
+
+        opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+        if (!opts)
+                return ERR_PTR(-ENOMEM);
+        opts->func_inst.free_func_inst = acm_free_instance;
+        return &opts->func_inst;
+}
+DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func);
+MODULE_LICENSE("GPL");
+#endif
diff --git a/drivers/usb/gadget/multi.c b/drivers/usb/gadget/multi.c
index 9ca0ac0334e7..24b0f5630d44 100644
--- a/drivers/usb/gadget/multi.c
+++ b/drivers/usb/gadget/multi.c
@@ -41,7 +41,7 @@ MODULE_LICENSE("GPL");
  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  */
 #include "f_mass_storage.c"
-
+#define USB_FACM_INCLUDED
 #include "f_acm.c"
 
 #include "f_ecm.c"
diff --git a/drivers/usb/gadget/nokia.c b/drivers/usb/gadget/nokia.c
index 084d0d7cb8fa..def37403989a 100644
--- a/drivers/usb/gadget/nokia.c
+++ b/drivers/usb/gadget/nokia.c
@@ -37,6 +37,7 @@
  * 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_FACM_INCLUDED
 #include "f_acm.c"
 #include "f_ecm.c"
 #include "f_obex.c"
diff --git a/drivers/usb/gadget/serial.c b/drivers/usb/gadget/serial.c
index a883562f6a89..68d7bb06ebcb 100644
--- a/drivers/usb/gadget/serial.c
+++ b/drivers/usb/gadget/serial.c
@@ -36,7 +36,6 @@
  * the runtime footprint, and giving us at least some parts of what
  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  */
-#include "f_acm.c"
 #include "f_obex.c"
 #include "f_serial.c"
 
@@ -129,16 +128,6 @@ MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
 /*-------------------------------------------------------------------------*/
 static unsigned char tty_lines[MAX_U_SERIAL_PORTS];
 
-static int __init serial_bind_acm_config(struct usb_configuration *c)
-{
-        unsigned i;
-        int status = 0;
-
-        for (i = 0; i < n_ports && status == 0; i++)
-                status = acm_bind_config(c, tty_lines[i]);
-        return status;
-}
-
 static int __init serial_bind_obex_config(struct usb_configuration *c)
 {
         unsigned i;
@@ -166,13 +155,58 @@ static struct usb_configuration serial_config_driver = {
         .bmAttributes   = USB_CONFIG_ATT_SELFPOWER,
 };
 
-static int gs_unbind(struct usb_composite_dev *cdev)
+static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
+static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
+
+static int serial_register_ports(struct usb_composite_dev *cdev,
+                struct usb_configuration *c, const char *f_name)
 {
         int i;
+        int ret;
+
+        ret = usb_add_config_only(cdev, c);
+        if (ret)
+                goto out;
+
+        for (i = 0; i < n_ports; i++) {
+                struct f_serial_opts *opts;
+
+                fi_serial[i] = usb_get_function_instance(f_name);
+                if (IS_ERR(fi_serial[i])) {
+                        ret = PTR_ERR(fi_serial[i]);
+                        goto fail;
+                }
+                opts = container_of(fi_serial[i], struct f_serial_opts, func_inst);
+                opts->port_num = tty_lines[i];
+
+                f_serial[i] = usb_get_function(fi_serial[i]);
+                if (IS_ERR(f_serial[i])) {
+                        ret = PTR_ERR(f_serial[i]);
+                        goto err_get_func;
+                }
+
+                ret = usb_add_function(c, f_serial[i]);
+                if (ret)
+                        goto err_add_func;
+        }
 
-        for (i = 0; i < n_ports; i++)
-                gserial_free_line(tty_lines[i]);
         return 0;
+
+err_add_func:
+        usb_put_function(f_serial[i]);
+err_get_func:
+        usb_put_function_instance(fi_serial[i]);
+
+fail:
+        i--;
+        while (i >= 0) {
+                usb_remove_function(c, f_serial[i]);
+                usb_put_function(f_serial[i]);
+                usb_put_function_instance(fi_serial[i]);
+                i--;
+        }
+out:
+        return ret;
 }
 
 static int __init gs_bind(struct usb_composite_dev *cdev)
@@ -204,10 +238,11 @@ static int __init gs_bind(struct usb_composite_dev *cdev)
         }
 
         /* register our configuration */
-        if (use_acm)
-                status = usb_add_config(cdev, &serial_config_driver,
-                                serial_bind_acm_config);
-        else if (use_obex)
+        if (use_acm) {
+                status  = serial_register_ports(cdev, &serial_config_driver,
+                                "acm");
+                usb_ep_autoconfig_reset(cdev->gadget);
+        } else if (use_obex)
                 status = usb_add_config(cdev, &serial_config_driver,
                                 serial_bind_obex_config);
         else
@@ -228,6 +263,18 @@ fail:
         return status;
 }
 
+static int gs_unbind(struct usb_composite_dev *cdev)
+{
+        int i;
+
+        for (i = 0; i < n_ports; i++) {
+                usb_put_function(f_serial[i]);
+                usb_put_function_instance(fi_serial[i]);
+                gserial_free_line(tty_lines[i]);
+        }
+        return 0;
+}
+
 static __refdata struct usb_composite_driver gserial_driver = {
         .name           = "g_serial",
         .dev            = &device_desc,
diff --git a/drivers/usb/gadget/u_serial.h b/drivers/usb/gadget/u_serial.h
index f06ee9a5db51..66ce73a00509 100644
--- a/drivers/usb/gadget/u_serial.h
+++ b/drivers/usb/gadget/u_serial.h
@@ -17,6 +17,11 @@
 
 #define MAX_U_SERIAL_PORTS      4
 
+struct f_serial_opts {
+        struct usb_function_instance func_inst;
+        u8 port_num;
+};
+
 /*
  * One non-multiplexed "serial" I/O port ... there can be several of these
  * on any given USB peripheral device, if it provides enough endpoints.