Re: [PATCH] HID: appleir: add support for Apple ir devices

From: Benjamin Tissoires
Date: Wed Apr 10 2013 - 12:36:05 EST


Hi Jiri,

On 04/09/2013 10:10 PM, Jiri Kosina wrote:
> On Mon, 8 Apr 2013, Benjamin Tissoires wrote:
>
>> This driver was originally written by James McKenzie, updated by
>> Greg Kroah-Hartman, further updated by Bastien Nocera, with suspend
>> support added.
>> I ported it to the HID subsystem, in order to simplify it a litle
>> and allow lirc to use it through hiddev.
>>
>> More recent versions of the IR receiver are also supported through
>> a patch by Alex Karpenko. The patch also adds support for the 2nd
>> and 5th generation of the controller, and the menu key on newer
>> brushed metal remotes.
>>
>> Tested-by: Fabien André <fabien.andre@xxxxxxxxx>
>> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
>> ---
>> Hi guys,
>>
>> this is the re-spin of Bastien's patch submitted last november.
>> I ported it to use the hid subsystem, reducing the size of the driver
>> to 355 lines instead of 527.
>
> Thanks. Generally, I like the idea of appleir being on the hid bus.

Thanks for the review.

>
> Bastien, could you please provide your Ack (and most importantly also
> Tested-by?).
>
> [ ... snip ... ]
>> +static void dump_packet(struct appleir *appleir, char *msg, u8 *data, int len)
>> +{
>> + appleir_dbg(appleir->hid,
>> + "appleir: %s (%d bytes) %*ph (should be command %d)\n",
>> + msg, len, len, data, (data[4] >> 1) & KEY_MASK);
>> +}
>
> Can't we just use HID debugfs interface for this kind of debugging output?

sure. I'll change this in v2.

>
>> +static int get_key(int data)
>> +{
>> + /*
>> + * The indexes of the keys are computed like this:
>> + * 0x00 or 0x01 ( ) key: 0 -> KEY_RESERVED
>> + * 0x02 or 0x03 ( menu ) key: 1 -> KEY_MENU
>> + * 0x04 or 0x05 ( >" ) key: 2 -> KEY_PLAYPAUSE
>> + * 0x06 or 0x07 ( >> ) key: 3 -> KEY_FORWARD
>> + * 0x08 or 0x09 ( << ) key: 4 -> KEY_BACK
>> + * 0x0a or 0x0b ( + ) key: 5 -> KEY_VOLUMEUP
>> + * 0x0c or 0x0d ( - ) key: 6 -> KEY_VOLUMEDOWN
>> + * 0x0e or 0x0f ( ) key: 7 -> KEY_RESERVED
>> + * 0x50 or 0x51 ( ) key: -8 -> KEY_RESERVED
>> + * 0x52 or 0x53 ( ) key: -9 -> KEY_RESERVED
>> + * 0x54 or 0x55 ( ) key: -10 -> KEY_RESERVED
>> + * 0x56 or 0x57 ( ) key: -11 -> KEY_RESERVED
>> + * 0x58 or 0x59 ( ) key: -12 -> KEY_RESERVED
>> + * 0x5a or 0x5b ( ) key: -13 -> KEY_RESERVED
>> + * 0x5c or 0x5d ( middle ) key: -14 -> KEY_ENTER
>> + * 0x5e or 0x5f ( >" ) key: -15 -> KEY_PLAYPAUSE
>> + */
>> + int key = (data >> 1) & KEY_MASK;
>> +
>> + if ((data & TWO_PACKETS_MASK))
>> + /* Part of a 2 packet-command */
>> + key = -key;
>
> I think all the shuffling with negative indices would justify an
> explanatory comment; it's quite confusing on a first sight.

Agree :)
I think I'll drop the '-' (minus) in this table, and add a comment
telling that those starting with 0x5 are part of a two packets report,
and we tag it by adding a minus in front of them.

>
> [ ... snip ... ]
>> +static int appleir_raw_event(struct hid_device *hid, struct hid_report *report,
>> + u8 *data, int len)
>> +{
>> + struct appleir *appleir = hid_get_drvdata(hid);
>> + static const u8 keydown[] = { 0x25, 0x87, 0xee };
>> + static const u8 keyrepeat[] = { 0x26, };
>> + static const u8 flatbattery[] = { 0x25, 0x87, 0xe0 };
>> + unsigned long flags;
>> +
>> + if (debug)
>> + dump_packet(appleir, "received", data, len);
>> +
>> + if (len != 5)
>> + goto out;
>> +
>> + if (!memcmp(data, keydown, sizeof(keydown))) {
>> + int index;
>> +
>> + spin_lock_irqsave(&appleir->lock, flags);
>> + /* If we already have a key down, take it up before marking
>> + this one down */
>
> Could you please make this comment in-line with kernel comments coding
> style?

Sure. I missed this one.

Thanks again for the review.

Cheers,
Benjamin

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