Pocketbook: Add support for waveform presets. (#1218)

Ship "slow, but always work" baseline, that can be
bumped from UI up to a level that still works.

ffi-cdecl/include/mxcfb-pb.h

@@ -107,20 +107,22 @@ struct mxcfb_rect {
 #define EPDC_WFTYPE_GC16			2
 #define EPDC_WFTYPE_GC4				3
 #define EPDC_WFTYPE_A2				4
-#define EPDC_WFTYPE_GL16			5
+#define EPDC_WFTYPE_GL16			5 // On B288 this is very fast, but flickers, interferes with HWROT.
 #define EPDC_WFTYPE_A2IN			6
 #define EPDC_WFTYPE_A2OUT			7
-#define EPDC_WFTYPE_DU4				8
-#define EPDC_WFTYPE_AA				9
-#define EPDC_WFTYPE_AAD				10
-#define EPDC_WFTYPE_GC16HQ			15
+#define EPDC_WFTYPE_DU4				8 // not B288
+#define EPDC_WFTYPE_AA				9 // not B288
+#define EPDC_WFTYPE_AAD				10 // not B288
+#define EPDC_WFTYPE_GS16			14 // B288 only. More aggressive than GC16, less than GL16.
+#define EPDC_WFTYPE_GC16HQ			15 // not B288
 // NOTE: Alias that to our usual constant names...
 #define WAVEFORM_MODE_INIT			EPDC_WFTYPE_INIT
 #define WAVEFORM_MODE_DU			EPDC_WFTYPE_DU
 #define WAVEFORM_MODE_GC16			EPDC_WFTYPE_GC16
 #define WAVEFORM_MODE_GC4			EPDC_WFTYPE_GC4
 #define WAVEFORM_MODE_A2			EPDC_WFTYPE_A2
 #define WAVEFORM_MODE_GL16			EPDC_WFTYPE_GL16
+#define WAVEFORM_MODE_GS16			EPDC_WFTYPE_GS16
 #define WAVEFORM_MODE_A2IN			EPDC_WFTYPE_A2IN
 #define WAVEFORM_MODE_A2OUT			EPDC_WFTYPE_A2OUT
 #define WAVEFORM_MODE_DU4			EPDC_WFTYPE_DU4
@@ -246,6 +248,9 @@ struct mxcfb_csc_matrix {
 //       >_<".
 //       c.f., https://github.com/koreader/koreader-base/pull/1188 & https://github.com/koreader/koreader/pull/6669
 
+// This only probes whether EPDC is busy, we use this to detect B288.
+#define EPDC_GET_UPDATE_STATE          _IOR('F', 0x55, __u32)
+
 #define MXCFB_SET_PWRDOWN_DELAY		_IOW('F', 0x30, int32_t)
 #define MXCFB_GET_PWRDOWN_DELAY		_IOR('F', 0x31, int32_t)
 #define MXCFB_SET_UPDATE_SCHEME		_IOW('F', 0x32, __u32)

ffi-cdecl/mxcfb_pb_decl.c

@@ -19,6 +19,7 @@ cdecl_const(EPDC_WFTYPE_GC16)
 cdecl_const(EPDC_WFTYPE_GC4)
 cdecl_const(EPDC_WFTYPE_A2)
 cdecl_const(EPDC_WFTYPE_GL16)
+cdecl_const(EPDC_WFTYPE_GS16)
 cdecl_const(EPDC_WFTYPE_A2IN)
 cdecl_const(EPDC_WFTYPE_A2OUT)
 cdecl_const(EPDC_WFTYPE_DU4)
@@ -31,6 +32,7 @@ cdecl_const(WAVEFORM_MODE_GC16)
 cdecl_const(WAVEFORM_MODE_GC4)
 cdecl_const(WAVEFORM_MODE_A2)
 cdecl_const(WAVEFORM_MODE_GL16)
+cdecl_const(WAVEFORM_MODE_GS16)
 cdecl_const(WAVEFORM_MODE_A2IN)
 cdecl_const(WAVEFORM_MODE_A2OUT)
 cdecl_const(WAVEFORM_MODE_DU4)
@@ -61,3 +63,4 @@ cdecl_struct(mxcfb_update_marker_data)
 
 cdecl_const(MXCFB_SEND_UPDATE)
 cdecl_const(MXCFB_WAIT_FOR_UPDATE_COMPLETE_PB)
+cdecl_const(EPDC_GET_UPDATE_STATE)

ffi/framebuffer.lua

@@ -33,6 +33,10 @@ local fb = {
         default = nil, -- if not nil, use this as default rotation value (this one is canonical, not HW)
         every_paint = false, -- true if HW mode should be enforced for every paint batch
     },]]
+    -- User-selectable WF aggressiveness.
+    -- Lower level is the slowest and most conservative, increasing values trade speed for glitches and ghosting.
+    wf_level = 0,
+    wf_level_max = 0, -- Maximum supported value for wf_level.
 }
 
 --[[
@@ -449,6 +453,10 @@ function fb:setupDithering()
     end
 end
 
+function fb:getWaveformLevel()
+    return math.min(self.wf_level_max, self.wf_level)
+end
+
 function fb:saveCurrentBB()
     if self.saved_bb then self.saved_bb:free() end
     self.saved_bb = self.bb:copy()

ffi/framebuffer_linux.lua

@@ -181,6 +181,7 @@ function framebuffer:setRotationMode(mode)
         self.cur_rotation_mode = mode
         self:setHWRotation(mode)
         self:reinit()
+        assert(self.forced_rotation, "reinit/fb hooks shouldn't flip hw rotation flags")
         if self.forced_rotation.restore then
             self:setHWRotation(self.native_rotation_mode)
         end

ffi/framebuffer_mxcfb.lua

@@ -554,6 +554,13 @@ function framebuffer:refreshFastImp(x, y, w, h, dither)
     self:mech_refresh(C.UPDATE_MODE_PARTIAL, self.waveform_fast, x, y, w, h, dither)
 end
 
+-- Detect Allwinner boards. Those emulate mxcfb API in a custom driver (poorly).
+function framebuffer:isB288(fb)
+    require("ffi/mxcfb_pocketbook_h")
+    -- On a real MXC driver, it returns -EINVAL
+    return C.ioctl(self.fd, C.EPDC_GET_UPDATE_STATE, ffi.new("uint32_t[1]")) == 0
+end
+
 function framebuffer:init()
     framebuffer.parent.init(self)
 
@@ -721,11 +728,29 @@ function framebuffer:init()
         self.mech_refresh = refresh_pocketbook
         self.mech_wait_update_complete = pocketbook_mxc_wait_for_update_complete
 
-        self.waveform_fast = C.WAVEFORM_MODE_DU
-        self.waveform_ui = C.WAVEFORM_MODE_GL16
+        self.wf_level_max = 3
+        local level = self:getWaveformLevel()
+        -- Level 0 is most conservative.
+        -- This is what inkview does on all platforms.
+        -- Slow (>150ms on B288 Carta).
+        if level == 0 then
+            self.waveform_fast = C.WAVEFORM_MODE_GC16
+            self.waveform_partial = C.WAVEFORM_MODE_GC16
+        elseif level == 1 then
+            self.waveform_fast = C.WAVEFORM_MODE_DU
+            self.waveform_partial = C.WAVEFORM_MODE_GC16
+        elseif level == 2 then
+            self.waveform_fast = C.WAVEFORM_MODE_DU
+            self.waveform_partial = self:isB288() and C.WAVEFORM_MODE_GS16 or C.WAVEFORM_MODE_GC16
+        -- Level 3 is most aggressive.
+        -- Fast (>80ms on B288 Carta), but flickers and may be buggy.
+        elseif level == 3 then
+            self.waveform_fast = C.WAVEFORM_MODE_DU
+            self.waveform_partial = C.WAVEFORM_MODE_GL16
+        end
+        self.waveform_ui = self.waveform_partial
         self.waveform_flashui = C.WAVEFORM_MODE_GC16
         self.waveform_full = C.WAVEFORM_MODE_GC16
-        self.waveform_partial = C.WAVEFORM_MODE_GL16
         self.waveform_night = C.WAVEFORM_MODE_GC16
         self.waveform_flashnight = self.waveform_night
         self.night_is_reagl = false

ffi/mxcfb_pocketbook_h.lua

@@ -11,6 +11,7 @@ static const int EPDC_WFTYPE_GC16 = 2;
 static const int EPDC_WFTYPE_GC4 = 3;
 static const int EPDC_WFTYPE_A2 = 4;
 static const int EPDC_WFTYPE_GL16 = 5;
+static const int EPDC_WFTYPE_GS16 = 14;
 static const int EPDC_WFTYPE_A2IN = 6;
 static const int EPDC_WFTYPE_A2OUT = 7;
 static const int EPDC_WFTYPE_DU4 = 8;
@@ -23,6 +24,7 @@ static const int WAVEFORM_MODE_GC16 = 2;
 static const int WAVEFORM_MODE_GC4 = 3;
 static const int WAVEFORM_MODE_A2 = 4;
 static const int WAVEFORM_MODE_GL16 = 5;
+static const int WAVEFORM_MODE_GS16 = 14;
 static const int WAVEFORM_MODE_A2IN = 6;
 static const int WAVEFORM_MODE_A2OUT = 7;
 static const int WAVEFORM_MODE_DU4 = 8;
@@ -68,4 +70,5 @@ struct mxcfb_update_marker_data {
 };
 static const int MXCFB_SEND_UPDATE = 1077954094;
 static const int MXCFB_WAIT_FOR_UPDATE_COMPLETE_PB = 1074021935;
+static const int EPDC_GET_UPDATE_STATE = 2147763797;
 ]]