[U-Boot] [PATCH v2 06/12] USB: gadget: added a saner gadget downloader registration API

[Marek Vasut]

On Tuesday, February 04, 2014 at 06:02:38 PM, Mateusz Zalega wrote:
> Preprocessor definitions and hardcoded implementation selection in
> g_dnl core were replaced by a linker list made of (usb_function_name,
> bind_callback) pairs.
> 
> Signed-off-by: Mateusz Zalega <m.zalega at samsung.com>
> Cc: Lukasz Majewski <l.majewski at samsung.com>
> Cc: Marek Vasut <marex at denx.de>

[...]

> +
> +/* export dfu_add to g_dnl.o */
> +ll_entry_declare(struct g_dnl_bind_callback, dfu_bind_callback,
> +		g_dnl_bind_callbacks) = { .usb_function_name = "usb_dnl_dfu",
> +					  .fptr = dfu_add };


from linker-lists.h quote:

104  * ll_entry_declare() - Declare linker-generated array entry
[...]
110  * This macro declares a variable that is placed into a linker-generated
111  * array. This is a basic building block for more advanced use of linker-
112  * generated arrays. The user is expected to build their own macro wrapper
113  * around this one.

Can you follow this advice and build a macro for declaring these USB devices ?

btw would you mind fixing the example for ll_entry_declare() in linker-lists.h ? 
It has four params in the example for some reason (it's a remnant from rework).

[...]

> +static inline struct g_dnl_bind_callback * g_dnl_first_bind_callback(void)
> +{
> +	return ll_entry_start(struct g_dnl_bind_callback,
> +				g_dnl_bind_callbacks);
> +}
> +
> +static inline struct g_dnl_bind_callback * g_dnl_last_bind_callback(void)
> +{
> +	return ll_entry_end(struct g_dnl_bind_callback,
> +				g_dnl_bind_callbacks);
> +}
> +

Are these two new functions called from multiple places at all? If not, just 
inline these ll_foo() calls and be done with it. FYI you can also make macros 
for these to avoid having to type all these args all around and duplicating the 
code.

>  static int g_dnl_do_config(struct usb_configuration *c)
>  {
>  	const char *s = c->cdev->driver->name;
> -	int ret = -1;
> 
>  	debug("%s: configuration: 0x%p composite dev: 0x%p\n",
> -	      __func__, c, c->cdev);
> -
> +			__func__, c, c->cdev);
>  	printf("GADGET DRIVER: %s\n", s);
> -	if (!strcmp(s, "usb_dnl_dfu"))
> -		ret = dfu_add(c);
> -	else if (!strcmp(s, "usb_dnl_ums"))
> -		ret = fsg_add(c);
> -	else if (!strcmp(s, "usb_dnl_thor"))
> -		ret = thor_add(c);
> -
> -	return ret;
> +
> +	struct g_dnl_bind_callback *callback = g_dnl_first_bind_callback();
> +	for (; callback != g_dnl_last_bind_callback(); ++callback)

callback++ , this is not C++ where the order might matter. Nonetheless, you do 
want to use ll_entry_count() and ll_entry_get() with an iterator variable 
instead to make sure you don't step onto a corrupted field and crash in some 
weird way.

> +		if (!strcmp(s, callback->usb_function_name))
> +			return callback->fptr(c);
> +	return -ENODEV;
>  }
> 
>  static int g_dnl_config_register(struct usb_composite_dev *cdev)
> @@ -203,12 +210,12 @@ static int g_dnl_bind(struct usb_composite_dev *cdev)
>  		device_desc.bcdDevice = cpu_to_le16(gcnum);
>  	else {
>  		debug("%s: controller '%s' not recognized\n",
> -			shortname, gadget->name);
> +				__func__, gadget->name);
>  		device_desc.bcdDevice = __constant_cpu_to_le16(0x9999);
>  	}
> 
> -	debug("%s: calling usb_gadget_connect for "
> -			"controller '%s'\n", shortname, gadget->name);
> +	debug("%s: calling usb_gadget_connect for controller '%s'\n",
> +			__func__, gadget->name);

Please split all these cleanups into a separate patch.

[...]