Shanling Q1: enable multi-touch reporting

The FT6x06 driver used for the Shanling Q1's touchscreen
has been extended to report more than one touch point. It
can also return the gesture detected by the controller,
but this doesn't seem to report anything useful on the Q1.

Multi-touch is only useful in 3x3 grid mode since the Rockbox
button API cannot report more than one touch point.

The FiiO M3K uses the same driver so it's been updated to the
multi-touch API, but functionality is unchanged.

Change-Id: I4de42f44808d6eb902e3da212d8f936b7a5042c7

1 files changed, 39 insertions, 25 deletions

diff --git a/firmware/drivers/ft6x06.c b/firmware/drivers/ft6x06.c
index 538ca10480..c605ee0944 100644
--- a/firmware/drivers/ft6x06.c
+++ b/firmware/drivers/ft6x06.c
@@ -24,6 +24,16 @@
 #include "i2c-async.h"
 #include <string.h>
 
+#define BYTES_PER_POINT 6
+
+#ifdef FT6x06_SWAP_AXES
+# define POS_X pos_y
+# define POS_Y pos_x
+#else
+# define POS_X pos_x
+# define POS_Y pos_y
+#endif
+
 struct ft6x06_driver {
     /* i2c bus data */
     int i2c_cookie;
@@ -33,39 +43,42 @@ struct ft6x06_driver {
     ft6x06_event_cb event_cb;
 
     /* buffer for I2C transfers */
-    uint8_t raw_data[6];
+    uint8_t raw_data[1 + 2 + BYTES_PER_POINT * FT6x06_NUM_POINTS];
 };
 
 static struct ft6x06_driver ft_drv;
 struct ft6x06_state ft6x06_state;
 
+static inline void ft6x06_convert_point(const uint8_t* raw,
+                                        struct ft6x06_point* pt)
+{
+    pt->event    = (raw[0] >> 6) & 0x3;
+    pt->touch_id = (raw[2] >> 4) & 0xf;
+    pt->POS_X    = ((raw[0] & 0xf) << 8) | raw[1];
+    pt->POS_Y    = ((raw[2] & 0xf) << 8) | raw[3];
+    pt->weight   = raw[4];
+    pt->area     = (raw[5] >> 4) & 0xf;
+}
+
 static void ft6x06_i2c_callback(int status, i2c_descriptor* desc)
 {
     (void)desc;
     if(status != I2C_STATUS_OK)
         return;
 
-    int evt = ft_drv.raw_data[1] >> 6;
-    int tx = ft_drv.raw_data[2] | ((ft_drv.raw_data[1] & 0xf) << 8);
-    int ty = ft_drv.raw_data[4] | ((ft_drv.raw_data[3] & 0xf) << 8);
-
-    ft6x06_state.event = evt;
-#ifdef FT6x06_SWAP_AXES
-    ft6x06_state.pos_x = ty;
-    ft6x06_state.pos_y = tx;
-#else
-    ft6x06_state.pos_x = tx;
-    ft6x06_state.pos_y = ty;
-#endif
+    ft6x06_state.gesture = ft_drv.raw_data[1];
+    ft6x06_state.nr_points = ft_drv.raw_data[2] & 0xf;
+    for(int i = 0; i < FT6x06_NUM_POINTS; ++i) {
+        ft6x06_convert_point(&ft_drv.raw_data[3 + i * BYTES_PER_POINT],
+                             &ft6x06_state.points[i]);
+    }
 
-    ft_drv.event_cb(evt, ft6x06_state.pos_x, ft6x06_state.pos_y);
+    ft_drv.event_cb(&ft6x06_state);
 }
 
-static void ft6x06_dummy_event_cb(int evt, int tx, int ty)
+static void ft6x06_dummy_event_cb(struct ft6x06_state* state)
 {
-    (void)evt;
-    (void)tx;
-    (void)ty;
+    (void)state;
 }
 
 void ft6x06_init(void)
@@ -74,9 +87,10 @@ void ft6x06_init(void)
     memset(&ft_drv, 0, sizeof(ft_drv));
     ft_drv.event_cb = ft6x06_dummy_event_cb;
 
-    ft6x06_state.event = FT6x06_EVT_NONE;
-    ft6x06_state.pos_x = 0;
-    ft6x06_state.pos_y = 0;
+    memset(&ft6x06_state, 0, sizeof(struct ft6x06_state));
+    ft6x06_state.gesture = -1;
+    for(int i = 0; i < FT6x06_NUM_POINTS; ++i)
+        ft6x06_state.points[i].event = FT6x06_EVT_NONE;
 
     /* Reserve bus management cookie */
     ft_drv.i2c_cookie = i2c_async_reserve_cookies(FT6x06_BUS, 1);
@@ -85,16 +99,16 @@ void ft6x06_init(void)
     ft_drv.i2c_desc.slave_addr = FT6x06_ADDR;
     ft_drv.i2c_desc.bus_cond   = I2C_START | I2C_STOP;
     ft_drv.i2c_desc.tran_mode  = I2C_READ;
-    ft_drv.i2c_desc.buffer[0]  = &ft_drv.raw_data[5];
+    ft_drv.i2c_desc.buffer[0]  = &ft_drv.raw_data[0];
     ft_drv.i2c_desc.count[0]   = 1;
-    ft_drv.i2c_desc.buffer[1]  = &ft_drv.raw_data[0];
-    ft_drv.i2c_desc.count[1]   = 5;
+    ft_drv.i2c_desc.buffer[1]  = &ft_drv.raw_data[1];
+    ft_drv.i2c_desc.count[1]   = sizeof(ft_drv.raw_data) - 1;
     ft_drv.i2c_desc.callback   = ft6x06_i2c_callback;
     ft_drv.i2c_desc.arg        = 0;
     ft_drv.i2c_desc.next       = NULL;
 
     /* Set I2C register address */
-    ft_drv.raw_data[5] = 0x02;
+    ft_drv.raw_data[0] = 0x01;
 }
 
 void ft6x06_set_event_cb(ft6x06_event_cb cb)