diff mbox

[03/14] HID: core: implement generic .request()

Message ID 1392055139-19631-4-git-send-email-benjamin.tissoires@redhat.com (mailing list archive)
State New, archived
Delegated to: Jiri Kosina
Headers show

Commit Message

Benjamin Tissoires Feb. 10, 2014, 5:58 p.m. UTC
.request() can be emulated through .raw_request()
we can implement this emulation in hid-core, and make .request
not mandatory for transport layer drivers.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---
 drivers/hid/hid-core.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
 include/linux/hid.h    |  5 ++++-
 2 files changed, 48 insertions(+), 2 deletions(-)

Comments

David Herrmann Feb. 12, 2014, 10:25 a.m. UTC | #1
Hi

On Mon, Feb 10, 2014 at 6:58 PM, Benjamin Tissoires
<benjamin.tissoires@redhat.com> wrote:
> .request() can be emulated through .raw_request()
> we can implement this emulation in hid-core, and make .request
> not mandatory for transport layer drivers.
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> ---
>  drivers/hid/hid-core.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
>  include/linux/hid.h    |  5 ++++-
>  2 files changed, 48 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
> index 18fe49b..f36778a 100644
> --- a/drivers/hid/hid-core.c
> +++ b/drivers/hid/hid-core.c
> @@ -1248,6 +1248,11 @@ void hid_output_report(struct hid_report *report, __u8 *data)
>  }
>  EXPORT_SYMBOL_GPL(hid_output_report);
>
> +static int hid_report_len(struct hid_report *report)
> +{
> +       return ((report->size - 1) >> 3) + 1 + (report->id > 0) + 7;

Just for clarity, this is equivalent to the following, right?

return DIV_ROUND_UP(report->size, 8) + !!(report->id > 0) + 7;

I always have to read that shifting code twice to get it.. Maybe add a
comment explaining the different entries here.

> +}
> +
>  /*
>   * Allocator for buffer that is going to be passed to hid_output_report()
>   */
> @@ -1258,7 +1263,7 @@ u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
>          * of implement() working on 8 byte chunks
>          */
>
> -       int len = ((report->size - 1) >> 3) + 1 + (report->id > 0) + 7;
> +       int len = hid_report_len(report);
>
>         return kmalloc(len, flags);
>  }
> @@ -1314,6 +1319,44 @@ static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
>         return report;
>  }
>
> +/*
> + * Implement a generic .request() callback, using .raw_request()
> + * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
> + */
> +void __hid_request(struct hid_device *hid, struct hid_report *report,
> +               int reqtype)
> +{
> +       char *buf;
> +       int ret;
> +       int len;
> +
> +       if (!hid->ll_driver->raw_request)
> +               return;
> +
> +       buf = hid_alloc_report_buf(report, GFP_KERNEL);
> +       if (!buf)
> +               return;
> +
> +       len = hid_report_len(report);
> +
> +       if (reqtype == HID_REQ_SET_REPORT)
> +               hid_output_report(report, buf);
> +
> +       ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
> +                                         report->type, reqtype);
> +       if (ret < 0) {
> +               dbg_hid("unable to complete request: %d\n", ret);
> +               goto out;
> +       }
> +
> +       if (reqtype == HID_REQ_GET_REPORT)
> +               hid_input_report(hid, report->type, buf, ret, 0);
> +
> +out:
> +       kfree(buf);
> +}
> +EXPORT_SYMBOL_GPL(__hid_request);
> +

Looks good to me.

Reviewed-by: David Herrmann <dh.herrmann@gmail.com>

Thanks
David

>  int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size,
>                 int interrupt)
>  {
> diff --git a/include/linux/hid.h b/include/linux/hid.h
> index a837ede..09fbbd7 100644
> --- a/include/linux/hid.h
> +++ b/include/linux/hid.h
> @@ -753,6 +753,7 @@ struct hid_field *hidinput_get_led_field(struct hid_device *hid);
>  unsigned int hidinput_count_leds(struct hid_device *hid);
>  __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code);
>  void hid_output_report(struct hid_report *report, __u8 *data);
> +void __hid_request(struct hid_device *hid, struct hid_report *rep, int reqtype);
>  u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags);
>  struct hid_device *hid_allocate_device(void);
>  struct hid_report *hid_register_report(struct hid_device *device, unsigned type, unsigned id);
> @@ -965,7 +966,9 @@ static inline void hid_hw_request(struct hid_device *hdev,
>                                   struct hid_report *report, int reqtype)
>  {
>         if (hdev->ll_driver->request)
> -               hdev->ll_driver->request(hdev, report, reqtype);
> +               return hdev->ll_driver->request(hdev, report, reqtype);
> +
> +       __hid_request(hdev, report, reqtype);
>  }
>
>  /**
> --
> 1.8.3.1
>
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Benjamin Tissoires Feb. 13, 2014, 3:21 p.m. UTC | #2
On Wed, Feb 12, 2014 at 5:25 AM, David Herrmann <dh.herrmann@gmail.com> wrote:
> Hi
>
> On Mon, Feb 10, 2014 at 6:58 PM, Benjamin Tissoires
> <benjamin.tissoires@redhat.com> wrote:
>> .request() can be emulated through .raw_request()
>> we can implement this emulation in hid-core, and make .request
>> not mandatory for transport layer drivers.
>>
>> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
>> ---
>>  drivers/hid/hid-core.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
>>  include/linux/hid.h    |  5 ++++-
>>  2 files changed, 48 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
>> index 18fe49b..f36778a 100644
>> --- a/drivers/hid/hid-core.c
>> +++ b/drivers/hid/hid-core.c
>> @@ -1248,6 +1248,11 @@ void hid_output_report(struct hid_report *report, __u8 *data)
>>  }
>>  EXPORT_SYMBOL_GPL(hid_output_report);
>>
>> +static int hid_report_len(struct hid_report *report)
>> +{
>> +       return ((report->size - 1) >> 3) + 1 + (report->id > 0) + 7;
>
> Just for clarity, this is equivalent to the following, right?
>
> return DIV_ROUND_UP(report->size, 8) + !!(report->id > 0) + 7;

yes, it should (at least that's what I understand too :)

>
> I always have to read that shifting code twice to get it.. Maybe add a
> comment explaining the different entries here.

good idea.

>
>> +}
>> +
>>  /*
>>   * Allocator for buffer that is going to be passed to hid_output_report()
>>   */
>> @@ -1258,7 +1263,7 @@ u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
>>          * of implement() working on 8 byte chunks
>>          */
>>
>> -       int len = ((report->size - 1) >> 3) + 1 + (report->id > 0) + 7;
>> +       int len = hid_report_len(report);
>>
>>         return kmalloc(len, flags);
>>  }
>> @@ -1314,6 +1319,44 @@ static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
>>         return report;
>>  }
>>
>> +/*
>> + * Implement a generic .request() callback, using .raw_request()
>> + * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
>> + */
>> +void __hid_request(struct hid_device *hid, struct hid_report *report,
>> +               int reqtype)
>> +{
>> +       char *buf;
>> +       int ret;
>> +       int len;
>> +
>> +       if (!hid->ll_driver->raw_request)
>> +               return;
>> +
>> +       buf = hid_alloc_report_buf(report, GFP_KERNEL);
>> +       if (!buf)
>> +               return;
>> +
>> +       len = hid_report_len(report);

actually, after sending the patches, I was wondering if we should use
the +7 in hid_report_len.
"len" is used in .raw_request(), and the +7 was only for the implement(), right?

So maybe a device can reject this because the size of the report is too big...

Jiri, David, any ideas?

Cheers,
Benjamin

>> +
>> +       if (reqtype == HID_REQ_SET_REPORT)
>> +               hid_output_report(report, buf);
>> +
>> +       ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
>> +                                         report->type, reqtype);
>> +       if (ret < 0) {
>> +               dbg_hid("unable to complete request: %d\n", ret);
>> +               goto out;
>> +       }
>> +
>> +       if (reqtype == HID_REQ_GET_REPORT)
>> +               hid_input_report(hid, report->type, buf, ret, 0);
>> +
>> +out:
>> +       kfree(buf);
>> +}
>> +EXPORT_SYMBOL_GPL(__hid_request);
>> +
>
> Looks good to me.
>
> Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
>
> Thanks
> David
>
>>  int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size,
>>                 int interrupt)
>>  {
>> diff --git a/include/linux/hid.h b/include/linux/hid.h
>> index a837ede..09fbbd7 100644
>> --- a/include/linux/hid.h
>> +++ b/include/linux/hid.h
>> @@ -753,6 +753,7 @@ struct hid_field *hidinput_get_led_field(struct hid_device *hid);
>>  unsigned int hidinput_count_leds(struct hid_device *hid);
>>  __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code);
>>  void hid_output_report(struct hid_report *report, __u8 *data);
>> +void __hid_request(struct hid_device *hid, struct hid_report *rep, int reqtype);
>>  u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags);
>>  struct hid_device *hid_allocate_device(void);
>>  struct hid_report *hid_register_report(struct hid_device *device, unsigned type, unsigned id);
>> @@ -965,7 +966,9 @@ static inline void hid_hw_request(struct hid_device *hdev,
>>                                   struct hid_report *report, int reqtype)
>>  {
>>         if (hdev->ll_driver->request)
>> -               hdev->ll_driver->request(hdev, report, reqtype);
>> +               return hdev->ll_driver->request(hdev, report, reqtype);
>> +
>> +       __hid_request(hdev, report, reqtype);
>>  }
>>
>>  /**
>> --
>> 1.8.3.1
>>
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David Herrmann Feb. 16, 2014, 4:43 p.m. UTC | #3
Hi

On Thu, Feb 13, 2014 at 4:21 PM, Benjamin Tissoires
<benjamin.tissoires@gmail.com> wrote:
> On Wed, Feb 12, 2014 at 5:25 AM, David Herrmann <dh.herrmann@gmail.com> wrote:
>> Hi
>>
>> On Mon, Feb 10, 2014 at 6:58 PM, Benjamin Tissoires
>> <benjamin.tissoires@redhat.com> wrote:
>>> .request() can be emulated through .raw_request()
>>> we can implement this emulation in hid-core, and make .request
>>> not mandatory for transport layer drivers.
>>>
>>> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
>>> ---
>>>  drivers/hid/hid-core.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
>>>  include/linux/hid.h    |  5 ++++-
>>>  2 files changed, 48 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
>>> index 18fe49b..f36778a 100644
>>> --- a/drivers/hid/hid-core.c
>>> +++ b/drivers/hid/hid-core.c
>>> @@ -1248,6 +1248,11 @@ void hid_output_report(struct hid_report *report, __u8 *data)
>>>  }
>>>  EXPORT_SYMBOL_GPL(hid_output_report);
>>>
>>> +static int hid_report_len(struct hid_report *report)
>>> +{
>>> +       return ((report->size - 1) >> 3) + 1 + (report->id > 0) + 7;
>>
>> Just for clarity, this is equivalent to the following, right?
>>
>> return DIV_ROUND_UP(report->size, 8) + !!(report->id > 0) + 7;
>
> yes, it should (at least that's what I understand too :)
>
>>
>> I always have to read that shifting code twice to get it.. Maybe add a
>> comment explaining the different entries here.
>
> good idea.
>
>>
>>> +}
>>> +
>>>  /*
>>>   * Allocator for buffer that is going to be passed to hid_output_report()
>>>   */
>>> @@ -1258,7 +1263,7 @@ u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
>>>          * of implement() working on 8 byte chunks
>>>          */
>>>
>>> -       int len = ((report->size - 1) >> 3) + 1 + (report->id > 0) + 7;
>>> +       int len = hid_report_len(report);
>>>
>>>         return kmalloc(len, flags);
>>>  }
>>> @@ -1314,6 +1319,44 @@ static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
>>>         return report;
>>>  }
>>>
>>> +/*
>>> + * Implement a generic .request() callback, using .raw_request()
>>> + * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
>>> + */
>>> +void __hid_request(struct hid_device *hid, struct hid_report *report,
>>> +               int reqtype)
>>> +{
>>> +       char *buf;
>>> +       int ret;
>>> +       int len;
>>> +
>>> +       if (!hid->ll_driver->raw_request)
>>> +               return;
>>> +
>>> +       buf = hid_alloc_report_buf(report, GFP_KERNEL);
>>> +       if (!buf)
>>> +               return;
>>> +
>>> +       len = hid_report_len(report);
>
> actually, after sending the patches, I was wondering if we should use
> the +7 in hid_report_len.
> "len" is used in .raw_request(), and the +7 was only for the implement(), right?
>
> So maybe a device can reject this because the size of the report is too big...
>
> Jiri, David, any ideas?

Yeah, we should allocate the +7 size, but we shouldn't use it as
"length" argument. We should just silently guarantee the buffer is big
enough.

Thanks
David

> Cheers,
> Benjamin
>
>>> +
>>> +       if (reqtype == HID_REQ_SET_REPORT)
>>> +               hid_output_report(report, buf);
>>> +
>>> +       ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
>>> +                                         report->type, reqtype);
>>> +       if (ret < 0) {
>>> +               dbg_hid("unable to complete request: %d\n", ret);
>>> +               goto out;
>>> +       }
>>> +
>>> +       if (reqtype == HID_REQ_GET_REPORT)
>>> +               hid_input_report(hid, report->type, buf, ret, 0);
>>> +
>>> +out:
>>> +       kfree(buf);
>>> +}
>>> +EXPORT_SYMBOL_GPL(__hid_request);
>>> +
>>
>> Looks good to me.
>>
>> Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
>>
>> Thanks
>> David
>>
>>>  int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size,
>>>                 int interrupt)
>>>  {
>>> diff --git a/include/linux/hid.h b/include/linux/hid.h
>>> index a837ede..09fbbd7 100644
>>> --- a/include/linux/hid.h
>>> +++ b/include/linux/hid.h
>>> @@ -753,6 +753,7 @@ struct hid_field *hidinput_get_led_field(struct hid_device *hid);
>>>  unsigned int hidinput_count_leds(struct hid_device *hid);
>>>  __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code);
>>>  void hid_output_report(struct hid_report *report, __u8 *data);
>>> +void __hid_request(struct hid_device *hid, struct hid_report *rep, int reqtype);
>>>  u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags);
>>>  struct hid_device *hid_allocate_device(void);
>>>  struct hid_report *hid_register_report(struct hid_device *device, unsigned type, unsigned id);
>>> @@ -965,7 +966,9 @@ static inline void hid_hw_request(struct hid_device *hdev,
>>>                                   struct hid_report *report, int reqtype)
>>>  {
>>>         if (hdev->ll_driver->request)
>>> -               hdev->ll_driver->request(hdev, report, reqtype);
>>> +               return hdev->ll_driver->request(hdev, report, reqtype);
>>> +
>>> +       __hid_request(hdev, report, reqtype);
>>>  }
>>>
>>>  /**
>>> --
>>> 1.8.3.1
>>>
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diff mbox

Patch

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 18fe49b..f36778a 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1248,6 +1248,11 @@  void hid_output_report(struct hid_report *report, __u8 *data)
 }
 EXPORT_SYMBOL_GPL(hid_output_report);
 
+static int hid_report_len(struct hid_report *report)
+{
+	return ((report->size - 1) >> 3) + 1 + (report->id > 0) + 7;
+}
+
 /*
  * Allocator for buffer that is going to be passed to hid_output_report()
  */
@@ -1258,7 +1263,7 @@  u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
 	 * of implement() working on 8 byte chunks
 	 */
 
-	int len = ((report->size - 1) >> 3) + 1 + (report->id > 0) + 7;
+	int len = hid_report_len(report);
 
 	return kmalloc(len, flags);
 }
@@ -1314,6 +1319,44 @@  static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
 	return report;
 }
 
+/*
+ * Implement a generic .request() callback, using .raw_request()
+ * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
+ */
+void __hid_request(struct hid_device *hid, struct hid_report *report,
+		int reqtype)
+{
+	char *buf;
+	int ret;
+	int len;
+
+	if (!hid->ll_driver->raw_request)
+		return;
+
+	buf = hid_alloc_report_buf(report, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	len = hid_report_len(report);
+
+	if (reqtype == HID_REQ_SET_REPORT)
+		hid_output_report(report, buf);
+
+	ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
+					  report->type, reqtype);
+	if (ret < 0) {
+		dbg_hid("unable to complete request: %d\n", ret);
+		goto out;
+	}
+
+	if (reqtype == HID_REQ_GET_REPORT)
+		hid_input_report(hid, report->type, buf, ret, 0);
+
+out:
+	kfree(buf);
+}
+EXPORT_SYMBOL_GPL(__hid_request);
+
 int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, int size,
 		int interrupt)
 {
diff --git a/include/linux/hid.h b/include/linux/hid.h
index a837ede..09fbbd7 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -753,6 +753,7 @@  struct hid_field *hidinput_get_led_field(struct hid_device *hid);
 unsigned int hidinput_count_leds(struct hid_device *hid);
 __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code);
 void hid_output_report(struct hid_report *report, __u8 *data);
+void __hid_request(struct hid_device *hid, struct hid_report *rep, int reqtype);
 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags);
 struct hid_device *hid_allocate_device(void);
 struct hid_report *hid_register_report(struct hid_device *device, unsigned type, unsigned id);
@@ -965,7 +966,9 @@  static inline void hid_hw_request(struct hid_device *hdev,
 				  struct hid_report *report, int reqtype)
 {
 	if (hdev->ll_driver->request)
-		hdev->ll_driver->request(hdev, report, reqtype);
+		return hdev->ll_driver->request(hdev, report, reqtype);
+
+	__hid_request(hdev, report, reqtype);
 }
 
 /**