Re: [PATCH v5 7/8] Input: elantech - add v3 hardware support

Hi JJ,

On Mon, Sep 5, 2011 at 3:10 PM, JJ Ding [off-list ref] wrote:

Hi Daniel,

On Mon, 5 Sep 2011 12:35:28 +0800, Daniel Kurtz [off-list ref] wrote:

quoted

Hi JJ,

On Mon, Sep 5, 2011 at 10:16 AM, JJ Ding [off-list ref] wrote:

quoted

diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index 2ae7c49..c4ceefd 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c

@@ -108,6 +108,16 @@ static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
                       rc = -1;
               }
               break;
+
+       case 3:
+               if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+                   elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
+                   elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+                   elantech_ps2_command(psmouse, NULL, reg) ||
+                   elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
+                       rc = -1;
+               }
+               break;
       }

       if (rc)

@@ -154,6 +164,18 @@ static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
                       rc = -1;
               }
               break;
+
+       case 3:
+               if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+                   elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
+                   elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+                   elantech_ps2_command(psmouse, NULL, reg) ||
+                   elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+                   elantech_ps2_command(psmouse, NULL, val) ||
+                   elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
+                       rc = -1;
+               }
+               break;
       }

       if (rc)

@@ -350,6 +372,84 @@ static void elantech_report_absolute_v2(struct psmouse *psmouse)
       input_sync(dev);
 }

+/*
+ * 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]);
+               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;
+       }
+
+       pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
+       width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
+
+       input_report_key(dev, BTN_TOUCH, fingers != 0);
+       if (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);

Originally, v3 was using semi-mt, which reported corner coordinates of
a box containing at least two of the N touches on the touchpad.  I
thought this was due to hardware limitation.

If the hardware really can report true positions for (up to) 3
contacts, then using pure MT-B is a good approach.  This driver still
seems to mix semi-mt and MT-B together a bit.

Can you report all three contacts in their own slots, 0, 1 and 2,
instead of just reoprting two of them with 0,1?

Also, when reporting the 'legacy single touch' coordinate (ABS_X,
ABS_Y), please use:
input_mt_report_pointer_emulation(), instead of always reporting the
last (x1,y1).  Otherwise the single touch point will bounce back and
forth between 1st and 3rd touch.

v3 can only track the true positions of two fingers. With 3 finger
touch, it reports the lowest value of x and the biggest value of y,
among the three fingers. v3 changed the protocol so it could report
2-finger touch data w/o reduced resolution and improved the hardware to
truly track 2 fingers independently, otherwise it's pretty much the same
as v2.

If I read this code correctly, it looks like in the 3-finger case,
(x1,y1) as reported in the (ABS_X, ABS_Y), and in the call to
elantech_report_semi_mt_data() will bounce back and forth between the
1st finger and 3rd finger ("lowest value of x and the biggest value of
y").  Won't this be very confusing for userspace (i.e.
xf86-input=synaptics)?

In fact, I'm not sure how "lowest value of x and the biggest value of
y" can be reported to userspace in a useful way at the same time as
two absolute finger positions.

Perhaps just report up to 2 MT-B slots, for the first two fingers, and
only report "3 fingers on the pad" with BTN_TOOL_TRIPLETAP  (see the
recent "synaptics image sensor" patchset for a similar
implementation):
https://patchwork.kernel.org/patch/1076142/

Thanks,
-Dan

quoted

quoted

+       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);

Use input_mt_report_pointer_emulation() with use_count = true.   This
will also report ABS_PRESURE (but not ABS_TOOL_WIDTH, unfortunately).

quoted

+       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);
+}
+
 static int elantech_packet_check_v1(struct psmouse *psmouse)
 {
       struct elantech_data *etd = psmouse->private;

@@ -403,11 +503,37 @@ static int elantech_packet_check_v2(struct psmouse *psmouse)
 }

 /*
+ * We check the constant bits to determine what packet type we get,
+ * so packet checking is mandatory for v3 hardware.
+ */
+static int elantech_packet_check_v3(struct psmouse *psmouse)
+{
+       const u8 debounce_packet[] = { 0xc4, 0xff, 0xff, 0x02, 0xff, 0xff };
+       unsigned char *packet = psmouse->packet;
+
+       /*
+        * check debounce first, it has the same signature in byte 0
+        * and byte 3 as PACKET_V3_HEAD.
+        */
+       if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
+               return PACKET_DEBOUNCE;
+
+       if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
+               return PACKET_V3_HEAD;
+
+       if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
+               return PACKET_V3_TAIL;
+
+       return PACKET_UNKNOWN;
+}
+
+/*
 * Process byte stream from mouse and handle complete packets
 */
 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
 {
       struct elantech_data *etd = psmouse->private;
+       int packet_type;

       if (psmouse->pktcnt < psmouse->pktsize)
               return PSMOUSE_GOOD_DATA;

@@ -429,6 +555,18 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)

               elantech_report_absolute_v2(psmouse);
               break;
+
+       case 3:
+               packet_type = elantech_packet_check_v3(psmouse);
+               /* ignore debounce */
+               if (packet_type == PACKET_DEBOUNCE)
+                       return PSMOUSE_FULL_PACKET;
+
+               if (packet_type == PACKET_UNKNOWN)
+                       return PSMOUSE_BAD_DATA;
+
+               elantech_report_absolute_v3(psmouse, packet_type);
+               break;
       }

       return PSMOUSE_FULL_PACKET;

@@ -463,8 +601,15 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse)
                   elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
                   elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
                       rc = -1;
-                       break;
               }
+               break;
+
+       case 3:
+               etd->reg_10 = 0x0b;
+               if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
+                       rc = -1;
+
+               break;
       }

       if (rc == 0) {

@@ -498,11 +643,12 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse)
       return rc;
 }

-static void set_range(struct psmouse *psmouse, unsigned int *x_min,
+static int set_range(struct psmouse *psmouse, unsigned int *x_min,
                    unsigned int *y_min, unsigned int *x_max,
                    unsigned int *y_max)
 {
       struct elantech_data *etd = psmouse->private;
+       unsigned char param[3];
       int i;

       switch (etd->hw_version) {

@@ -530,19 +676,30 @@ static void set_range(struct psmouse *psmouse, unsigned int *x_min,
                       *y_max = (etd->capabilities[2] - i) * 64;
               }
               break;
+
+       case 3:
+               if (synaptics_send_cmd(psmouse, ETP_FW_ID_QUERY, param))
+                       return -1;
+
+               *x_max = (0x0f & param[0]) << 8 | param[1];
+               *y_max = (0xf0 & param[0]) << 4 | param[2];
+               break;
       }
+
+       return 0;
 }

 /*
 * 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;

-       set_range(psmouse, &x_min, &y_min, &x_max, &y_max);
+       if (set_range(psmouse, &x_min, &y_min, &x_max, &y_max))
+               return -1;

       __set_bit(EV_KEY, dev->evbit);
       __set_bit(EV_ABS, dev->evbit);

@@ -570,6 +727,9 @@ static void elantech_set_input_params(struct psmouse *psmouse)

       case 2:
               __set_bit(BTN_TOOL_QUADTAP, dev->keybit);
+               __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
+               /* fall through */
+       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);
               if (etd->reports_pressure) {

@@ -578,7 +738,6 @@ static void elantech_set_input_params(struct psmouse *psmouse)
                       input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
                                            ETP_WMAX_V2, 0, 0);
               }
-               __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
               input_mt_init_slots(dev, 2);

Should this be 3?

quoted

               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);

@@ -586,6 +745,8 @@ static void elantech_set_input_params(struct psmouse *psmouse)
       }

       etd->y_max = y_max;
+
+       return 0;
 }

 struct elantech_attr_data {

@@ -727,7 +888,8 @@ int elantech_detect(struct psmouse *psmouse, bool set_properties)
        * Report this in case there are Elantech models that use a different
        * set of magic numbers
        */
-       if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
+       if (param[0] != 0x3c || param[1] != 0x03 ||
+           (param[2] != 0xc8 && param[2] != 0x00)) {
               pr_debug("unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
                        param[0], param[1], param[2]);
               return -1;

@@ -793,16 +955,16 @@ static int elantech_reconnect(struct psmouse *psmouse)
 /*
 * determine hardware version and set some properties according to it.
 */
-static void elantech_set_properties(struct elantech_data *etd)
+static int elantech_set_properties(struct elantech_data *etd)
 {
-       /*
-        * Assume every version greater than 0x020030 is new EeePC style
-        * hardware with 6 byte packets, except 0x020600
-        */
       if (etd->fw_version < 0x020030 || etd->fw_version == 0x020600)
               etd->hw_version = 1;
-       else
+       else if (etd->fw_version < 0x150600)
               etd->hw_version = 2;
+       else if ((etd->fw_version & 0x0f0000) >> 16 == 5)
+               etd->hw_version = 3;
+       else
+               return -1;

       /*
        * Turn on packet checking by default.

@@ -817,13 +979,15 @@ static void elantech_set_properties(struct elantech_data *etd)
       etd->jumpy_cursor =
               (etd->fw_version == 0x020022 || etd->fw_version == 0x020600);

-       if (etd->hw_version == 2) {
+       if (etd->hw_version > 1) {
               /* For now show extra debug information */
               etd->debug = 1;

               if (etd->fw_version >= 0x020800)
                       etd->reports_pressure = true;
       }
+
+       return 0;
 }

 /*

@@ -850,9 +1014,12 @@ int elantech_init(struct psmouse *psmouse)
               pr_err("failed to query firmware version.\n");
               goto init_fail;
       }
-
       etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
-       elantech_set_properties(etd);
+
+       if (elantech_set_properties(etd)) {
+               pr_err("unknown hardware version, aborting...\n");
+               goto init_fail;
+       }
       pr_info("assuming hardware version %d "
               "(with firmware version 0x%02x%02x%02x)\n",
               etd->hw_version, param[0], param[1], param[2]);

@@ -871,7 +1038,10 @@ int elantech_init(struct psmouse *psmouse)
               goto init_fail;
       }

-       elantech_set_input_params(psmouse);
+       if (elantech_set_input_params(psmouse)) {
+               pr_err("failed to query touchpad range.\n");
+               goto init_fail;
+       }

       error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
                                  &elantech_attr_group);

@@ -883,7 +1053,7 @@ int elantech_init(struct psmouse *psmouse)
       psmouse->protocol_handler = elantech_process_byte;
       psmouse->disconnect = elantech_disconnect;
       psmouse->reconnect = elantech_reconnect;
-       psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;
+       psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;

       return 0;

diff --git a/drivers/input/mouse/elantech.h b/drivers/input/mouse/elantech.h
index d9e6144..236c33c 100644
--- a/drivers/input/mouse/elantech.h
+++ b/drivers/input/mouse/elantech.h

@@ -16,6 +16,7 @@
 /*
 * Command values for Synaptics style queries
 */
+#define ETP_FW_ID_QUERY                        0x00
 #define ETP_FW_VERSION_QUERY           0x01
 #define ETP_CAPABILITIES_QUERY         0x02

@@ -24,6 +25,7 @@
 */
 #define ETP_REGISTER_READ              0x10
 #define ETP_REGISTER_WRITE             0x11
+#define ETP_REGISTER_READWRITE         0x00

 /*
 * Hardware version 2 custom PS/2 command value

@@ -79,6 +81,14 @@
 #define ETP_WMIN_V2                    0
 #define ETP_WMAX_V2                    15

+/*
+ * v3 hardware has 2 kinds of packet types.
+ */
+#define PACKET_UNKNOWN                 0x01
+#define PACKET_DEBOUNCE                        0x02
+#define PACKET_V3_HEAD                 0x03
+#define PACKET_V3_TAIL                 0x04
+
 struct elantech_data {
       unsigned char reg_10;
       unsigned char reg_11;

@@ -98,6 +108,8 @@ struct elantech_data {
       unsigned int fw_version;
       unsigned int single_finger_reports;
       unsigned int y_max;
+       unsigned int prev_x;
+       unsigned int prev_y;
       unsigned char parity[256];
 };

--

1.7.4.1