* [RFC] Simple but effective way of changing HID device descriptors (resent)
@ 2009-12-24 2:29 Marcin Tolysz
2009-12-24 8:39 ` Antonio Ospite
0 siblings, 1 reply; 3+ messages in thread
From: Marcin Tolysz @ 2009-12-24 2:29 UTC (permalink / raw)
To: linux-input
[-- Attachment #1: Type: text/plain, Size: 2559 bytes --]
Simple but effective way of changing HID device descriptors using
firmware loading mechanism.
Just place your new descriptor in a location specified by driver
i.e. somewhere in /lib/firmware/hid/
If it is there it will replace HID descriptor from the device.
I do not do any parsing or checking, as it is done by hid driver.
Signed-off-by: Marcin Tolysz <tolysz@gmail.com>
---
drivers/hid/hid-core.c | 26 +++++++++++++++++++++++++-
1 files changed, 25 insertions(+), 1 deletions(-)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 80792d3..5d8d656 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -27,6 +27,7 @@
#include <linux/wait.h>
#include <linux/vmalloc.h>
#include <linux/sched.h>
+#include <linux/firmware.h>
#include <linux/hid.h>
#include <linux/hiddev.h>
@@ -640,6 +641,10 @@ int hid_parse_report(struct hid_device *device,
__u8 *start,
struct hid_item item;
__u8 *end;
int ret;
+ const struct firmware *fw;
+ int succ;
+ char *file;
+
static int (*dispatch_type[])(struct hid_parser *parser,
struct hid_item *item) = {
hid_parser_main,
@@ -650,10 +655,27 @@ int hid_parse_report(struct hid_device *device,
__u8 *start,
if (device->driver->report_fixup)
device->driver->report_fixup(device, start, size);
+ /* Now load a hid descriptor from a file firmware
+ ignoring this fixup thing */
+ file=kmalloc(29, GFP_KERNEL);
+
sprintf(file,"hid/%04X:%04X:%04X:%04X.bin",device->bus,device->vendor,device->product,device->version);
+
+ succ = request_firmware(&fw, file, &device->dev);
+
+ if (succ)
+ printk(KERN_INFO "To relace HID descriptor place it in
/lib/firmaware/%s\n", file);
+ else{
+ start = fw->data;
+ size = fw->size;
+ printk(KERN_INFO "HID descriptor relaced with /lib/firmaware/%s\n",
file);
+ }
+ kfree(file);
device->rdesc = kmalloc(size, GFP_KERNEL);
- if (device->rdesc == NULL)
+ if (device->rdesc == NULL){
+ if(!succ)release_firmware(fw);
return -ENOMEM;
+ }
memcpy(device->rdesc, start, size);
device->rsize = size;
@@ -690,6 +712,7 @@ int hid_parse_report(struct hid_device *device, __u8
*start,
dbg_hid("unbalanced delimiter at end of report description\n");
goto err;
}
+ if(!succ)release_firmware(fw);
vfree(parser);
return 0;
}
@@ -697,6 +720,7 @@ int hid_parse_report(struct hid_device *device, __u8
*start,
dbg_hid("item fetching failed at offset %d\n", (int)(end - start));
err:
+ if(!succ)release_firmware(fw);
vfree(parser);
return ret;
}
-- 1.6.5.7
[-- Attachment #2: 0001-Simple-but-effective-way-of-chaging-HID-device-descr.patch --]
[-- Type: text/x-patch, Size: 2784 bytes --]
>From 85bc06073ad4d18f44757c2c72f9f8409ecf3ac5 Mon Sep 17 00:00:00 2001
From: Marcin Tolysz <tolysz@gmail.com>
To: <linux-input@vger.kernel.org>
Date: Thu, 24 Dec 2009 01:40:34 +0000
Subject: [RFC] Simple but effective way of chaging HID device descriptors
Simple but effective way of chaging HID device descriptorsusing firmware loading mechanism.
Just place your new descriptor in a location specified by driver
i.e. somewhere in /lib/firmware/hid/
If it is there it will replace HID descriptor from the device.
I do not do any parsing or checking, as it is done by hid driver.
Signed-off-by: Marcin Tolysz <tolysz@gmail.com>
---
drivers/hid/hid-core.c | 26 +++++++++++++++++++++++++-
1 files changed, 25 insertions(+), 1 deletions(-)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 80792d3..5d8d656 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -27,6 +27,7 @@
#include <linux/wait.h>
#include <linux/vmalloc.h>
#include <linux/sched.h>
+#include <linux/firmware.h>
#include <linux/hid.h>
#include <linux/hiddev.h>
@@ -640,6 +641,10 @@ int hid_parse_report(struct hid_device *device, __u8 *start,
struct hid_item item;
__u8 *end;
int ret;
+ const struct firmware *fw;
+ int succ;
+ char *file;
+
static int (*dispatch_type[])(struct hid_parser *parser,
struct hid_item *item) = {
hid_parser_main,
@@ -650,10 +655,27 @@ int hid_parse_report(struct hid_device *device, __u8 *start,
if (device->driver->report_fixup)
device->driver->report_fixup(device, start, size);
+ /* Now load a hid descriptor from a file firmware
+ ignoring this fixup thing */
+ file=kmalloc(29, GFP_KERNEL);
+ sprintf(file,"hid/%04X:%04X:%04X:%04X.bin",device->bus,device->vendor,device->product,device->version);
+
+ succ = request_firmware(&fw, file, &device->dev);
+
+ if (succ)
+ printk(KERN_INFO "To relace HID descriptor place it in /lib/firmaware/%s\n", file);
+ else{
+ start = fw->data;
+ size = fw->size;
+ printk(KERN_INFO "HID descriptor relaced with /lib/firmaware/%s\n", file);
+ }
+ kfree(file);
device->rdesc = kmalloc(size, GFP_KERNEL);
- if (device->rdesc == NULL)
+ if (device->rdesc == NULL){
+ if(!succ)release_firmware(fw);
return -ENOMEM;
+ }
memcpy(device->rdesc, start, size);
device->rsize = size;
@@ -690,6 +712,7 @@ int hid_parse_report(struct hid_device *device, __u8 *start,
dbg_hid("unbalanced delimiter at end of report description\n");
goto err;
}
+ if(!succ)release_firmware(fw);
vfree(parser);
return 0;
}
@@ -697,6 +720,7 @@ int hid_parse_report(struct hid_device *device, __u8 *start,
dbg_hid("item fetching failed at offset %d\n", (int)(end - start));
err:
+ if(!succ)release_firmware(fw);
vfree(parser);
return ret;
}
--
1.6.5.7
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [RFC] Simple but effective way of changing HID device descriptors (resent)
2009-12-24 2:29 [RFC] Simple but effective way of changing HID device descriptors (resent) Marcin Tolysz
@ 2009-12-24 8:39 ` Antonio Ospite
2009-12-31 17:28 ` Marcin Tolysz
0 siblings, 1 reply; 3+ messages in thread
From: Antonio Ospite @ 2009-12-24 8:39 UTC (permalink / raw)
To: Marcin Tolysz; +Cc: linux-input
[-- Attachment #1: Type: text/plain, Size: 3706 bytes --]
On Thu, 24 Dec 2009 02:29:47 +0000
Marcin Tolysz <tolysz@gmail.com> wrote:
> Simple but effective way of changing HID device descriptors using
> firmware loading mechanism.
> Just place your new descriptor in a location specified by driver
> i.e. somewhere in /lib/firmware/hid/
> If it is there it will replace HID descriptor from the device.
> I do not do any parsing or checking, as it is done by hid driver.
>
> Signed-off-by: Marcin Tolysz <tolysz@gmail.com>
>
Only some style comments below, I haven't tested the patch. Plus, try
running the patch through scripts/checkpatch.pl to spot all the other
style issues.
> ---
> drivers/hid/hid-core.c | 26 +++++++++++++++++++++++++-
> 1 files changed, 25 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
> index 80792d3..5d8d656 100644
> --- a/drivers/hid/hid-core.c
> +++ b/drivers/hid/hid-core.c
> @@ -27,6 +27,7 @@
> #include <linux/wait.h>
> #include <linux/vmalloc.h>
> #include <linux/sched.h>
> +#include <linux/firmware.h>
>
> #include <linux/hid.h>
> #include <linux/hiddev.h>
> @@ -640,6 +641,10 @@ int hid_parse_report(struct hid_device *device,
> __u8 *start,
> struct hid_item item;
> __u8 *end;
> int ret;
> + const struct firmware *fw;
> + int succ;
success? Can't you init fw to NULL and derive this info checking
(fw != NULL) before releasing firmware?
> + char *file;
> +
> static int (*dispatch_type[])(struct hid_parser *parser,
> struct hid_item *item) = {
> hid_parser_main,
> @@ -650,10 +655,27 @@ int hid_parse_report(struct hid_device *device,
> __u8 *start,
>
> if (device->driver->report_fixup)
> device->driver->report_fixup(device, start, size);
> + /* Now load a hid descriptor from a file firmware
> + ignoring this fixup thing */
> + file=kmalloc(29, GFP_KERNEL);
> +
> sprintf(file,"hid/%04X:%04X:%04X:%04X.bin",device->bus,device->vendor,device->product,device->version);
> +
What about removing this 29?
#define NEW_HID_DESCRIPTOR_PATH_FMT "hid/%04X:%04X:%04X:%04X.bin"
and use it in kmalloc with strlen and in sprintf.
> + succ = request_firmware(&fw, file, &device->dev);
> +
> + if (succ)
> + printk(KERN_INFO "To relace HID descriptor place it in
> /lib/firmaware/%s\n", file);
pr_info() could be used or maybe even dev_info()
> + else{
> + start = fw->data;
> + size = fw->size;
> + printk(KERN_INFO "HID descriptor relaced with /lib/firmaware/%s\n",
> file);
> + }
> + kfree(file);
>
> device->rdesc = kmalloc(size, GFP_KERNEL);
> - if (device->rdesc == NULL)
> + if (device->rdesc == NULL){
> + if(!succ)release_firmware(fw);
> return -ENOMEM;
> + }
> memcpy(device->rdesc, start, size);
> device->rsize = size;
>
> @@ -690,6 +712,7 @@ int hid_parse_report(struct hid_device *device, __u8
> *start,
> dbg_hid("unbalanced delimiter at end of report description\n");
> goto err;
> }
> + if(!succ)release_firmware(fw);
> vfree(parser);
> return 0;
> }
> @@ -697,6 +720,7 @@ int hid_parse_report(struct hid_device *device, __u8
> *start,
>
> dbg_hid("item fetching failed at offset %d\n", (int)(end - start));
> err:
> + if(!succ)release_firmware(fw);
> vfree(parser);
> return ret;
> }
> -- 1.6.5.7
Regards,
Antonio
--
Antonio Ospite
http://ao2.it
PGP public key ID: 0x4553B001
A: Because it messes up the order in which people normally read text.
See http://en.wikipedia.org/wiki/Posting_style
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
[-- Attachment #2: Type: application/pgp-signature, Size: 198 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [RFC] Simple but effective way of changing HID device descriptors (resent)
2009-12-24 8:39 ` Antonio Ospite
@ 2009-12-31 17:28 ` Marcin Tolysz
0 siblings, 0 replies; 3+ messages in thread
From: Marcin Tolysz @ 2009-12-31 17:28 UTC (permalink / raw)
To: Antonio Ospite; +Cc: linux-input
Just to make sure the corrected patch is: [RFC v2] [HID] allow using
external Hid Descriptors.
2009/12/24 Antonio Ospite <ospite@studenti.unina.it>:
> On Thu, 24 Dec 2009 02:29:47 +0000
> Marcin Tolysz <tolysz@gmail.com> wrote:
>
>> Simple but effective way of changing HID device descriptors using
>> firmware loading mechanism.
>> Just place your new descriptor in a location specified by driver
>> i.e. somewhere in /lib/firmware/hid/
>> If it is there it will replace HID descriptor from the device.
>> I do not do any parsing or checking, as it is done by hid driver.
>>
>> Signed-off-by: Marcin Tolysz <tolysz@gmail.com>
>>
>
> Only some style comments below, I haven't tested the patch. Plus, try
> running the patch through scripts/checkpatch.pl to spot all the other
> style issues.
Corrected most of style errors but 3 too long lines.
>> ---
>> drivers/hid/hid-core.c | 26 +++++++++++++++++++++++++-
>> 1 files changed, 25 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
>> index 80792d3..5d8d656 100644
>> --- a/drivers/hid/hid-core.c
>> +++ b/drivers/hid/hid-core.c
>> @@ -27,6 +27,7 @@
>> #include <linux/wait.h>
>> #include <linux/vmalloc.h>
>> #include <linux/sched.h>
>> +#include <linux/firmware.h>
>>
>> #include <linux/hid.h>
>> #include <linux/hiddev.h>
>> @@ -640,6 +641,10 @@ int hid_parse_report(struct hid_device *device,
>> __u8 *start,
>> struct hid_item item;
>> __u8 *end;
>> int ret;
>> + const struct firmware *fw;
>> + int succ;
>
> success? Can't you init fw to NULL and derive this info checking
> (fw != NULL) before releasing firmware?
every other driver checks this value, fw is a structure thus I would
need to check fw->data;
>> + char *file;
>> +
>> static int (*dispatch_type[])(struct hid_parser *parser,
>> struct hid_item *item) = {
>> hid_parser_main,
>> @@ -650,10 +655,27 @@ int hid_parse_report(struct hid_device *device,
>> __u8 *start,
>>
>> if (device->driver->report_fixup)
>> device->driver->report_fixup(device, start, size);
>> + /* Now load a hid descriptor from a file firmware
>> + ignoring this fixup thing */
>> + file=kmalloc(29, GFP_KERNEL);
>> +
>> sprintf(file,"hid/%04X:%04X:%04X:%04X.bin",device->bus,device->vendor,device->product,device->version);
>> +
>
> What about removing this 29?
> #define NEW_HID_DESCRIPTOR_PATH_FMT "hid/%04X:%04X:%04X:%04X.bin"
> and use it in kmalloc with strlen and in sprintf.
replaced by:
file = kasprintf(GFP_KERNEL, "hid/%04X:%04X:%04X:%04X.bin",
device->bus, device->vendor, device->product,
device->version);
I did not putted it into define as this heavily depends on parameters,
and I do not want to separate them yet.
>> + succ = request_firmware(&fw, file, &device->dev);
>> +
>> + if (succ)
>> + printk(KERN_INFO "To relace HID descriptor place it in
>> /lib/firmaware/%s\n", file);
>
> pr_info() could be used or maybe even dev_info()
I went for pr_info.
>> + else{
>> + start = fw->data;
>> + size = fw->size;
>> + printk(KERN_INFO "HID descriptor relaced with /lib/firmaware/%s\n",
>> file);
>> + }
>> + kfree(file);
>>
>> device->rdesc = kmalloc(size, GFP_KERNEL);
>> - if (device->rdesc == NULL)
>> + if (device->rdesc == NULL){
>> + if(!succ)release_firmware(fw);
>> return -ENOMEM;
>> + }
>> memcpy(device->rdesc, start, size);
>> device->rsize = size;
>>
>> @@ -690,6 +712,7 @@ int hid_parse_report(struct hid_device *device, __u8
>> *start,
>> dbg_hid("unbalanced delimiter at end of report description\n");
>> goto err;
>> }
>> + if(!succ)release_firmware(fw);
>> vfree(parser);
>> return 0;
>> }
>> @@ -697,6 +720,7 @@ int hid_parse_report(struct hid_device *device, __u8
>> *start,
>>
>> dbg_hid("item fetching failed at offset %d\n", (int)(end - start));
>> err:
>> + if(!succ)release_firmware(fw);
>> vfree(parser);
>> return ret;
>> }
>> -- 1.6.5.7
>
> Regards,
> Antonio
Many thanks for your help.
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