Re: [PATCH 6/6] Input: elantech - add v3 hardware support

Tom _Lin
2011-08-22T07:14:53Z

Hi JJ
On Mon, 2011-08-22 at 14:05 +0800, JJ Ding wrote:
> Hi Éric,
>
> Thanks for your comments, a few lines below:
>
> On Fri, 19 Aug 2011 15:03:04 +0200, Éric Piel <E.A.B.Piel@tudelft.nl> wrote:
> > Op 18-08-11 03:57, JJ Ding schreef:
> > > v3 hardware's packet format is almost identical to v2 (one/three finger touch),
> > > except when sensing two finger touch, the hardware sends 12 bytes of data.
> > >
> > > Signed-off-by: JJ Ding<jj_ding@emc.com.tw>
> > Hi,
> > A couple of comments, in line.
> >
> > :
> > :
> > > diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
> > > index ddd40eb..e13a719 100644
> > > --- a/drivers/input/mouse/elantech.c
> > > +++ b/drivers/input/mouse/elantech.c
> > :
> > > +/*
> > > + * Interpret complete data packets and report absolute mode input events for
> > > + * hardware version 3. (12 byte packets for two fingers)
> > > + */
> > > +static void elantech_report_absolute_v3(struct psmouse *psmouse,
> > > + int packet_type)
> > > +{
> > > + struct input_dev *dev = psmouse->dev;
> > > + struct elantech_data *etd = psmouse->private;
> > > + unsigned char *packet = psmouse->packet;
> > > + unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
> > > + unsigned int width = 0, pres = 0;
> > > +
> > > + /* byte 0: n1 n0 . . . . R L */
> > > + fingers = (packet[0]& 0xc0)>> 6;
> > > +
> > > + switch (fingers) {
> > > + case 3:
> > > + case 1:
> > > + /*
> > > + * byte 1: . . . . x11 x10 x9 x8
> > > + * byte 2: x7 x6 x5 x4 x4 x2 x1 x0
> > > + */
> > > + x1 = ((packet[1]& 0x0f)<< 8) | packet[2];
> > > + /*
> > > + * byte 4: . . . . y11 y10 y9 y8
> > > + * byte 5: y7 y6 y5 y4 y3 y2 y1 y0
> > > + */
> > > + y1 = etd->y_max - (((packet[4]& 0x0f)<< 8) | packet[5]);
> > > +
> > > + if (fingers == 3&& debounce(x1, y1))
> > > + return;
> > > +
> > > + break;
> > > +
> > > + case 2:
> > > + if (packet_type == PACKET_V3_HEAD) {
> > > + /*
> > > + * byte 1: . . . . ax11 ax10 ax9 ax8
> > > + * byte 2: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
> > > + */
> > > + etd->prev_x = ((packet[1]& 0x0f)<< 8) | packet[2];
> > > + /*
> > > + * byte 4: . . . . ay11 ay10 ay9 ay8
> > > + * byte 5: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0
> > > + */
> > > + etd->prev_y = etd->y_max -
> > > + (((packet[4]& 0x0f)<< 8) | packet[5]);
> > > + /*
> > > + * wait for next packet
> > > + */
> > > + return;
> > > + }
> > > +
> > > + /* packet_type == PACKET_V3_TAIL */
> > > + x1 = etd->prev_x;
> > > + y1 = etd->prev_y;
> > > + x2 = ((packet[1]& 0x0f)<< 8) | packet[2];
> > > + y2 = etd->y_max - (((packet[4]& 0x0f)<< 8) | packet[5]);
> > > + break;
> > > + }
> > You actually have three times the same formula, so you could simplify it:
> >
> > if (fingers !=0 ) {
> > /*
> > * byte 1: . . . . x11 x10 x9 x8
> > * byte 2: x7 x6 x5 x4 x4 x2 x1 x0
> > */
> > x1 = ((packet[1]& 0x0f)<< 8) | packet[2];
> > /*
> > * byte 4: . . . . y11 y10 y9 y8
> > * byte 5: y7 y6 y5 y4 y3 y2 y1 y0
> > */
> > y1 = ((packet[4]& 0x0f)<< 8) | packet[5];
> > }
> >
> > if ((fingers == 3) && debounce(x1, y1))
> > return;
> we need one more line here, for fingers != 2 :
> y1 = etd->y_max - y1;
> > if (fingers == 2) {
> > if (packet_type == PACKET_V3_HEAD)) {
> > /* wait for next packet */
> > etd->prev_x = x1;
> > etd->prev_y = etd->y_max - y1;
> etd->prev_y = y1;
> > return;
> > } else {
> > /* packet_type == PACKET_V3_TAIL */
> > x2 = etd->prev_x;
> > y2 = etd->prev_y;
> > }
> > }
> I like this compact version, but it seems to me this is not as straight
> forward as the original switch case. I am OK with either. Is there
> anyone who has more to say about this?
Éric's version is compact but this is not straight forward as original
code and does not improve more performances. Then other versions of
"elantech_report_absolute" also needed to modify the same style . so I
prefer original style.
> >
> > > +
> > > + pres = (packet[1]& 0xf0) | ((packet[4]& 0xf0)>> 4);
> > > + width = ((packet[0]& 0x30)>> 2) | ((packet[3]& 0x30)>> 4);
> > What about the case of two fingers? Are pressure and width correct for
> > both fingers? In that case, maybe it should also be saved from
> > PACKET_V3_HEAD.
> I am told (by our firmware guy) that pres and width are sent the same
> value for two finger touch.
> >
> > > +
> > > + input_report_key(dev, BTN_TOUCH, fingers != 0);
> > > + input_report_abs(dev, ABS_X, x1);
> > > + input_report_abs(dev, ABS_Y, y1);
> > > + elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
> > > + input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
> > > + input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
> > > + input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
> > > + input_report_key(dev, BTN_LEFT, packet[0]& 0x01);
> > > + input_report_key(dev, BTN_RIGHT, packet[0]& 0x02);
> > > + input_report_abs(dev, ABS_PRESSURE, pres);
> > > + input_report_abs(dev, ABS_TOOL_WIDTH, width);
> > > +
> > > + input_sync(dev);
> > > +}
> > > +
> > :
> > >
> > > /*
> > > * Set the appropriate event bits for the input subsystem
> > > */
> > > -static void elantech_set_input_params(struct psmouse *psmouse)
> > > +static int elantech_set_input_params(struct psmouse *psmouse)
> > > {
> > > struct input_dev *dev = psmouse->dev;
> > > struct elantech_data *etd = psmouse->private;
> > > unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0, y_2ft_max = 0;
> > >
> > > - set_range(psmouse,&x_min,&y_min,&x_max,&y_max,&y_2ft_max);
> > > + if (set_range(psmouse,&x_min,&y_min,&x_max,&y_max,&y_2ft_max))
> > > + return -1;
> > >
> > > __set_bit(EV_KEY, dev->evbit);
> > > __set_bit(EV_ABS, dev->evbit);
> > > @@ -582,10 +739,26 @@ static void elantech_set_input_params(struct psmouse *psmouse)
> > > input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
> > > input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
> > > break;
> > > +
> > > + case 3:
> > > + input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
> > > + input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
> > > + /* range of pressure and width is the same as v2 */
> > > + input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
> > > + ETP_PMAX_V2, 0, 0);
> > > + input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
> > > + ETP_WMAX_V2, 0, 0);
> > > + __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
> > Does v3 have the same limitation in MT about only reporting the edges of
> > the bounding box? Or are the two fingers always reported independently?
> > If that is so, you can drop this line :-)
> I suppose it's the same as v2, but I have to comfirm with our firmware team.
> I will ckeck this.
> >
> > > + input_mt_init_slots(dev, 2);
> > > + input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
> > > + input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
> > > + break;
> > > }
> > >
> >
> > Cheers,
> > Éric
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-input" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>