Re: [PATCH] usb: gadget: nokia: Add mass storage driver to g_nokia

From: Krzysztof Opasiak
Date: Thu May 28 2015 - 10:51:24 EST

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In reply to: Pali RohÃr: "Re: [PATCH] usb: gadget: nokia: Add mass storage driver to g_nokia"
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On 05/28/2015 04:31 PM, Pali RohÃr wrote:

On Thursday 28 May 2015 16:27:44 Krzysztof Opasiak wrote:

On 05/28/2015 09:47 AM, Pali RohÃr wrote:

On Saturday 31 January 2015 10:53:30 Pali RohÃr wrote:

This patch adds removable mass storage support to g_nokia gadget (for N900).
It means that at runtime block device can be exported or unexported.
So it does not export anything by default and thus allows to use MyDocs
partition as before...

Signed-off-by: Pali RohÃr <pali.rohar@xxxxxxxxx>
---
drivers/usb/gadget/legacy/Kconfig | 1 +
drivers/usb/gadget/legacy/nokia.c | 102 ++++++++++++++++++++++++++++++++++++-
2 files changed, 102 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/legacy/Kconfig b/drivers/usb/gadget/legacy/Kconfig
index fd48ef3..36f6ba4 100644
--- a/drivers/usb/gadget/legacy/Kconfig
+++ b/drivers/usb/gadget/legacy/Kconfig
@@ -345,6 +345,7 @@ config USB_G_NOKIA
select USB_F_OBEX
select USB_F_PHONET
select USB_F_ECM
+ select USB_F_MASS_STORAGE
help
The Nokia composite gadget provides support for acm, obex
and phonet in only one composite gadget driver.
diff --git a/drivers/usb/gadget/legacy/nokia.c b/drivers/usb/gadget/legacy/nokia.c
index 9b8fd70..a09bb50 100644
--- a/drivers/usb/gadget/legacy/nokia.c
+++ b/drivers/usb/gadget/legacy/nokia.c
@@ -24,6 +24,7 @@
#include "u_phonet.h"
#include "u_ecm.h"
#include "gadget_chips.h"
+#include "f_mass_storage.h"

/* Defines */

@@ -34,6 +35,29 @@ USB_GADGET_COMPOSITE_OPTIONS();

USB_ETHERNET_MODULE_PARAMETERS();

+static struct fsg_module_parameters fsg_mod_data = {
+ .stall = 0,
+ .luns = 2,
+ .removable_count = 2,
+ .removable = { 1, 1, },
+};
+
+FSG_MODULE_PARAMETERS(/* no prefix */, fsg_mod_data);
+
+#ifdef CONFIG_USB_GADGET_DEBUG_FILES
+
+static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;
+
+#else
+
+/*
+ * Number of buffers we will use.
+ * 2 is usually enough for good buffering pipeline
+ */
+#define fsg_num_buffers CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
+
+#endif /* CONFIG_USB_DEBUG */
+
#define NOKIA_VENDOR_ID 0x0421 /* Nokia */
#define NOKIA_PRODUCT_ID 0x01c8 /* Nokia Gadget */

@@ -94,6 +118,8 @@ static struct usb_function *f_obex1_cfg2;
static struct usb_function *f_obex2_cfg2;
static struct usb_function *f_phonet_cfg1;
static struct usb_function *f_phonet_cfg2;
+static struct usb_function *f_msg_cfg1;
+static struct usb_function *f_msg_cfg2;

static struct usb_configuration nokia_config_500ma_driver = {
@@ -117,6 +143,7 @@ static struct usb_function_instance *fi_ecm;
static struct usb_function_instance *fi_obex1;
static struct usb_function_instance *fi_obex2;
static struct usb_function_instance *fi_phonet;
+static struct usb_function_instance *fi_msg;

static int __init nokia_bind_config(struct usb_configuration *c)
{
@@ -125,6 +152,8 @@ static int __init nokia_bind_config(struct usb_configuration *c)
struct usb_function *f_obex1 = NULL;
struct usb_function *f_ecm;
struct usb_function *f_obex2 = NULL;
+ struct usb_function *f_msg;
+ struct fsg_opts *fsg_opts;
int status = 0;
int obex1_stat = -1;
int obex2_stat = -1;
@@ -160,6 +189,12 @@ static int __init nokia_bind_config(struct usb_configuration *c)
goto err_get_ecm;
}

+ f_msg = usb_get_function(fi_msg);
+ if (IS_ERR(f_msg)) {
+ status = PTR_ERR(f_msg);
+ goto err_get_msg;
+ }
+
if (!IS_ERR_OR_NULL(f_phonet)) {
phonet_stat = usb_add_function(c, f_phonet);
if (phonet_stat)
@@ -187,21 +222,36 @@ static int __init nokia_bind_config(struct usb_configuration *c)
pr_debug("could not bind ecm config %d\n", status);
goto err_ecm;
}
+
+ fsg_opts = fsg_opts_from_func_inst(fi_msg);
+
+ status = fsg_common_run_thread(fsg_opts->common);
+ if (status)
+ goto err_msg;
+
+ status = usb_add_function(c, f_msg);
+ if (status)
+ goto err_msg;
+
if (c == &nokia_config_500ma_driver) {
f_acm_cfg1 = f_acm;
f_ecm_cfg1 = f_ecm;
f_phonet_cfg1 = f_phonet;
f_obex1_cfg1 = f_obex1;
f_obex2_cfg1 = f_obex2;
+ f_msg_cfg1 = f_msg;
} else {
f_acm_cfg2 = f_acm;
f_ecm_cfg2 = f_ecm;
f_phonet_cfg2 = f_phonet;
f_obex1_cfg2 = f_obex1;
f_obex2_cfg2 = f_obex2;
+ f_msg_cfg2 = f_msg;
}

return status;
+err_msg:
+ usb_remove_function(c, f_ecm);
err_ecm:
usb_remove_function(c, f_acm);
err_conf:
@@ -211,6 +261,8 @@ err_conf:
usb_remove_function(c, f_obex1);
if (!phonet_stat)
usb_remove_function(c, f_phonet);
+ usb_put_function(f_msg);
+err_get_msg:
usb_put_function(f_ecm);
err_get_ecm:
usb_put_function(f_acm);
@@ -227,6 +279,8 @@ err_get_acm:
static int __init nokia_bind(struct usb_composite_dev *cdev)
{
struct usb_gadget *gadget = cdev->gadget;
+ struct fsg_opts *fsg_opts;
+ struct fsg_config fsg_config;
int status;

status = usb_string_ids_tab(cdev, strings_dev);
@@ -267,11 +321,46 @@ static int __init nokia_bind(struct usb_composite_dev *cdev)
goto err_acm_inst;
}

+ fi_msg = usb_get_function_instance("mass_storage");
+ if (IS_ERR(fi_msg)) {
+ status = PTR_ERR(fi_msg);
+ goto err_ecm_inst;
+ }
+
+ /* set up mass storage function */
+ fsg_config_from_params(&fsg_config, &fsg_mod_data, fsg_num_buffers);
+ fsg_config.vendor_name = "Nokia";
+ fsg_config.product_name = "N900";
+
+ fsg_opts = fsg_opts_from_func_inst(fi_msg);
+ fsg_opts->no_configfs = true;
+
+ status = fsg_common_set_num_buffers(fsg_opts->common, fsg_num_buffers);
+ if (status)
+ goto err_msg_inst;
+
+ status = fsg_common_set_nluns(fsg_opts->common, fsg_config.nluns);
+ if (status)
+ goto err_msg_buf;
+
+ status = fsg_common_set_cdev(fsg_opts->common, cdev, fsg_config.can_stall);
+ if (status)
+ goto err_msg_set_nluns;
+
+ fsg_common_set_sysfs(fsg_opts->common, true);
+
+ status = fsg_common_create_luns(fsg_opts->common, &fsg_config);
+ if (status)
+ goto err_msg_set_nluns;
+
+ fsg_common_set_inquiry_string(fsg_opts->common, fsg_config.vendor_name,
+ fsg_config.product_name);
+
/* finally register the configuration */
status = usb_add_config(cdev, &nokia_config_500ma_driver,
nokia_bind_config);
if (status < 0)
- goto err_ecm_inst;
+ goto err_msg_set_cdev;

status = usb_add_config(cdev, &nokia_config_100ma_driver,
nokia_bind_config);
@@ -292,6 +381,14 @@ err_put_cfg1:
if (!IS_ERR_OR_NULL(f_phonet_cfg1))
usb_put_function(f_phonet_cfg1);
usb_put_function(f_ecm_cfg1);
+err_msg_set_cdev:
+ fsg_common_remove_luns(fsg_opts->common);
+err_msg_set_nluns:
+ fsg_common_free_luns(fsg_opts->common);
+err_msg_buf:
+ fsg_common_free_buffers(fsg_opts->common);
+err_msg_inst:
+ usb_put_function_instance(fi_msg);
err_ecm_inst:
usb_put_function_instance(fi_ecm);
err_acm_inst:
@@ -325,7 +422,10 @@ static int __exit nokia_unbind(struct usb_composite_dev *cdev)
usb_put_function(f_acm_cfg2);
usb_put_function(f_ecm_cfg1);
usb_put_function(f_ecm_cfg2);
+ usb_put_function(f_msg_cfg1);
+ usb_put_function(f_msg_cfg2);

+ usb_put_function_instance(fi_msg);
usb_put_function_instance(fi_ecm);
if (!IS_ERR(fi_obex2))
usb_put_function_instance(fi_obex2);

Opening discussion about this patch again as this is still only one
solution how to use use mass storage without breaking other stuff...

Please understand finally that usb networking is very very important for
development on this device and usb mass storage is needed for
transferring bigger data.

Also to clarify potential regressions: This patch adds *optional* usb
mass storage support and block device can be attached/detached to driver
at runtime. It does *not* enforce to export some (mmc) device
automatically. It is optional and userspace can decide...

So MyDocs N900 partition is not automatically enforced to be exported
via usb (as some people thought) and so it does not break usb networking
or mass storage mode or MyDocs parition on N900 with Maemo system.

Instead of adding mass storage to legacy gadget you may switch to
configfs interface and compose equivalent of g_nokia + mass storage
without any changes in kernel.

Best regards,

That requires userspace. And there are developers who use nfsroot via
usb networking and so userspace will be there after properly
initializing usb gadget... So it is not easy and reason why I'm opening
this discussion again.

Couldn't you simply use initramfs to compose your gadget?

--
Krzysztof Opasiak
Samsung R&D Institute Poland
Samsung Electronics
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Next message: Mike Galbraith: "Re: sched_setscheduler() vs idle_balance() race"
Previous message: Grygorii.Strashko@xxxxxxxxxx: "Re: [RFC v1] clk: Add Suspend/Resume Callbacks in Clock"
In reply to: Pali RohÃr: "Re: [PATCH] usb: gadget: nokia: Add mass storage driver to g_nokia"
Next in thread: Pali RohÃr: "Re: [PATCH] usb: gadget: nokia: Add mass storage driver to g_nokia"
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