On 08/12/2023 01:03, dean@xxxxxxxxxxxx wrote:
> Hi Hans,
>
>>> +static struct v4l2_ctrl_config v4l2_ctrl_deviceid = {
>>> + .ops = &s2255_ctrl_ops,
>>> + .name = "Device ID",
>>> + .id = V4L2_CID_S2255_DEVICEID,
>>> + .type = V4L2_CTRL_TYPE_INTEGER,
>>
>> Please note that TYPE_INTEGER is a signed integer.
>>
>> If you need an unsigned integer, then use TYPE_U32.
>
>
> It is unsigned, but it doesn't need to be. The max value should not run into a signed value. I can change the maximum value from 0xffffffff to 0x7fffffff.
>
> Is it acceptable to not use TYPE_U32 in order to simplify the user space calls?
Certainly!
Hans
>
> TYPE_U32 is a compound type. My understanding is VIDIOC_G_CTRL will not work with compound types and some V4L user programs may not implement the compound type queries.
>
> Best regards,
>
> Dean
>
>
>
>
> On 2023-12-06 03:43, Hans Verkuil wrote:
>> Hi Dean,
>>
>> Some comments below:
>>
>> On 22/11/2023 20:48, Dean Anderson wrote:
>>> Adding V4L2 read-only control id for device id as hardware
>>> does not support embedding the device-id in the USB device descriptors.
>>>
>>> base-commit: 3e238417254bfdcc23fe207780b59cbb08656762
>>
>> Just drop this line, it doesn't belong in a commit message.
>>
>>>
>>> Signed-off-by: Dean Anderson <dean@xxxxxxxxxxxx>
>>>
>>> ---
>>> drivers/media/usb/s2255/s2255drv.c | 49 +++++++++++++++++++++++++++++-
>>> 1 file changed, 48 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/media/usb/s2255/s2255drv.c b/drivers/media/usb/s2255/s2255drv.c
>>> index 3c2627712fe9..c2248bbc7840 100644
>>> --- a/drivers/media/usb/s2255/s2255drv.c
>>> +++ b/drivers/media/usb/s2255/s2255drv.c
>>> @@ -40,7 +40,7 @@
>>> #include <media/v4l2-ctrls.h>
>>> #include <media/v4l2-event.h>
>>>
>>> -#define S2255_VERSION "1.25.1"
>>> +#define S2255_VERSION "1.26.1"
>>> #define FIRMWARE_FILE_NAME "f2255usb.bin"
>>>
>>> /* default JPEG quality */
>>> @@ -60,6 +60,7 @@
>>> #define S2255_MIN_BUFS 2
>>> #define S2255_SETMODE_TIMEOUT 500
>>> #define S2255_VIDSTATUS_TIMEOUT 350
>>> +#define S2255_MARKER_FIRMWARE cpu_to_le32(0xDDCCBBAAL)
>>> #define S2255_MARKER_FRAME cpu_to_le32(0x2255DA4AL)
>>> #define S2255_MARKER_RESPONSE cpu_to_le32(0x2255ACACL)
>>> #define S2255_RESPONSE_SETMODE cpu_to_le32(0x01)
>>> @@ -323,6 +324,7 @@ struct s2255_buffer {
>>> #define S2255_V4L2_YC_ON 1
>>> #define S2255_V4L2_YC_OFF 0
>>> #define V4L2_CID_S2255_COLORFILTER (V4L2_CID_USER_S2255_BASE + 0)
>>> +#define V4L2_CID_S2255_DEVICEID (V4L2_CID_USER_S2255_BASE + 1)
>>>
>>> /* frame prefix size (sent once every frame) */
>>> #define PREFIX_SIZE 512
>>> @@ -1232,6 +1234,37 @@ static int s2255_s_ctrl(struct v4l2_ctrl *ctrl)
>>> return 0;
>>> }
>>>
>>> +/* deviceid/serial number is not used in usb device descriptors.
>>> + * returns device-id/serial number from device, 0 if none found.
>>
>> Please put the '/*' on a line by itself, that's consistent with the
>> coding style for multi-line comments.
>>
>> Also run the patch through 'checkpatch.pl --strict'. I get several
>> warnings.
>>
>> returns -> Returns
>>
>> One question about this comment: is the Device ID the same as a serial
>> number? "Device ID" can mean either the ID of a device model, or a unique
>> ID for each device. If it is the latter, should it perhaps be called
>> "Device S/N" or just "Serial Number"?
>>
>>> + */
>>> +#define S2255_DEVICEID_NONE 0
>>> +static int s2255_g_deviceid(struct s2255_dev *dev)
>>> +{
>>> + u8 *outbuf;
>>> + int rc;
>>> + int deviceid = S2255_DEVICEID_NONE;
>>> +#define S2255_I2C_SIZE 16
>>> + outbuf = kzalloc(S2255_I2C_SIZE * sizeof(u8), GFP_KERNEL);
>>
>> Drop the "* sizeof(u8)", it serves no purpose.
>>
>>> + if (outbuf == NULL)
>>> + return deviceid;
>>> +#define S2255_I2C_SNDEV 0xa2
>>> +#define S2255_I2C_SNOFFSET 0x1ff0
>>> +#define S2255_USBVENDOR_READREG 0x22
>>> + rc = s2255_vendor_req(dev, S2255_USBVENDOR_READREG, S2255_I2C_SNOFFSET,
>>> + S2255_I2C_SNDEV >> 1, outbuf, S2255_I2C_SIZE, 0);
>>> + if (rc < 0)
>>> + goto exit_g_deviceid;
>>> +
>>> + /* verify marker code */
>>> + if (*(__le32 *)outbuf != S2255_MARKER_FIRMWARE)
>>> + goto exit_g_deviceid;
>>> +
>>> + deviceid = (outbuf[12] << 24) + (outbuf[13] << 16) + (outbuf[14] << 8) + outbuf[15];
>>> +exit_g_deviceid:
>>> + kfree(outbuf);
>>> + return deviceid;
>>
>> This is overly complicated. How about this:
>>
>> /* verify marker code */
>> if (*(__le32 *)outbuf == S2255_MARKER_FIRMWARE)
>> deviceid = (outbuf[12] << 24) + (outbuf[13] << 16) + (outbuf[14] <<
>> 8) + outbuf[15];
>> kfree(outbuf);
>> return deviceid;
>>
>>> +}
>>> +
>>> static int vidioc_g_jpegcomp(struct file *file, void *priv,
>>> struct v4l2_jpegcompression *jc)
>>> {
>>> @@ -1581,6 +1614,17 @@ static const struct v4l2_ctrl_config color_filter_ctrl = {
>>> .def = 1,
>>> };
>>>
>>> +static struct v4l2_ctrl_config v4l2_ctrl_deviceid = {
>>> + .ops = &s2255_ctrl_ops,
>>> + .name = "Device ID",
>>> + .id = V4L2_CID_S2255_DEVICEID,
>>> + .type = V4L2_CTRL_TYPE_INTEGER,
>>
>> Please note that TYPE_INTEGER is a signed integer.
>>
>> If you need an unsigned integer, then use TYPE_U32.
>>
>>> + .max = 0xffffffff,
>>> + .min = 0,
>>> + .step = 1,
>>> + .flags = V4L2_CTRL_FLAG_READ_ONLY,
>>> +};
>>> +
>>> static int s2255_probe_v4l(struct s2255_dev *dev)
>>> {
>>> int ret;
>>> @@ -1615,6 +1659,9 @@ static int s2255_probe_v4l(struct s2255_dev *dev)
>>> (dev->pid != 0x2257 || vc->idx <= 1))
>>> v4l2_ctrl_new_custom(&vc->hdl, &color_filter_ctrl,
>>> NULL);
>>> + v4l2_ctrl_deviceid.def = s2255_g_deviceid(dev);
>>> + v4l2_ctrl_new_custom(&vc->hdl, &v4l2_ctrl_deviceid,
>>> + NULL);
>>> if (vc->hdl.error) {
>>> ret = vc->hdl.error;
>>> v4l2_ctrl_handler_free(&vc->hdl);
>>
>> Regards,
>>
>> Hans
