Spin off common ft6x06 code to a driver

Allows for the i2c boilerplate to be shared between the M3K and
Shanling Q1 ports. M3K-specific quirks remain in button-fiiom3k.

Change-Id: I8879b603cefc16416bb200f1c484ca916d935c6a

5 files changed, 210 insertions, 74 deletions

diff --git a/firmware/SOURCES b/firmware/SOURCES
index d28c189213..0a6d4d30c3 100644
--- a/firmware/SOURCES
+++ b/firmware/SOURCES
@@ -1928,13 +1928,18 @@ target/hosted/sdl/filesystem-sdl.c
 drivers/touchpad.c
 #endif
 
+/* Hardware drivers */
+#ifndef SIMULATOR
 #ifdef HAVE_I2C_ASYNC
 drivers/i2c-async.c
 #endif
-
 #ifdef HAVE_AXP_PMU
 drivers/axp-pmu.c
 #endif
+#ifdef HAVE_FT6x06
+drivers/ft6x06.c
+#endif
+#endif
 
 /* firmware/kernel section */
 #ifdef HAVE_CORELOCK_OBJECT
diff --git a/firmware/drivers/ft6x06.c b/firmware/drivers/ft6x06.c
new file mode 100644
index 0000000000..538ca10480
--- /dev/null
+++ b/firmware/drivers/ft6x06.c
@@ -0,0 +1,115 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2021 Aidan MacDonald
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "ft6x06.h"
+#include "kernel.h"
+#include "i2c-async.h"
+#include <string.h>
+
+struct ft6x06_driver {
+    /* i2c bus data */
+    int i2c_cookie;
+    i2c_descriptor i2c_desc;
+
+    /* callback for touch events */
+    ft6x06_event_cb event_cb;
+
+    /* buffer for I2C transfers */
+    uint8_t raw_data[6];
+};
+
+static struct ft6x06_driver ft_drv;
+struct ft6x06_state ft6x06_state;
+
+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
+
+    ft_drv.event_cb(evt, ft6x06_state.pos_x, ft6x06_state.pos_y);
+}
+
+static void ft6x06_dummy_event_cb(int evt, int tx, int ty)
+{
+    (void)evt;
+    (void)tx;
+    (void)ty;
+}
+
+void ft6x06_init(void)
+{
+    /* Initialize stuff */
+    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;
+
+    /* Reserve bus management cookie */
+    ft_drv.i2c_cookie = i2c_async_reserve_cookies(FT6x06_BUS, 1);
+
+    /* Prep an I2C descriptor to read touch data */
+    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.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.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;
+}
+
+void ft6x06_set_event_cb(ft6x06_event_cb cb)
+{
+    ft_drv.event_cb = cb ? cb : ft6x06_dummy_event_cb;
+}
+
+void ft6x06_enable(bool en)
+{
+    i2c_reg_write1(FT6x06_BUS, FT6x06_ADDR, 0xa5, en ? 0 : 3);
+}
+
+void ft6x06_irq_handler(void)
+{
+    /* We don't care if this fails, there's not much we can do about it */
+    i2c_async_queue(FT6x06_BUS, TIMEOUT_NOBLOCK, I2C_Q_ONCE,
+                    ft_drv.i2c_cookie, &ft_drv.i2c_desc);
+}
diff --git a/firmware/export/config/fiiom3k.h b/firmware/export/config/fiiom3k.h
index a28efd43a5..849aa9c0a6 100644
--- a/firmware/export/config/fiiom3k.h
+++ b/firmware/export/config/fiiom3k.h
@@ -22,6 +22,8 @@
 
 /* Drivers */
 #define HAVE_I2C_ASYNC
+#define HAVE_FT6x06
+#define FT6x06_SWAP_AXES
 
 /* Buffer for plugins and codecs. */
 #define PLUGIN_BUFFER_SIZE  0x200000 /* 2 MiB */
diff --git a/firmware/export/ft6x06.h b/firmware/export/ft6x06.h
new file mode 100644
index 0000000000..de1fdd0979
--- /dev/null
+++ b/firmware/export/ft6x06.h
@@ -0,0 +1,50 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2021 Aidan MacDonald
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#ifndef __FT6x06_H__
+#define __FT6x06_H__
+
+#include "config.h"
+#include <stdbool.h>
+
+typedef void(*ft6x06_event_cb)(int, int, int);
+
+struct ft6x06_state {
+    int event;
+    int pos_x;
+    int pos_y;
+};
+
+enum ft6x06_event {
+    FT6x06_EVT_NONE = -1,
+    FT6x06_EVT_PRESS = 0,
+    FT6x06_EVT_RELEASE = 1,
+    FT6x06_EVT_CONTACT = 2,
+};
+
+extern struct ft6x06_state ft6x06_state;
+
+void ft6x06_init(void);
+void ft6x06_set_event_cb(ft6x06_event_cb fn);
+void ft6x06_enable(bool en);
+void ft6x06_irq_handler(void);
+
+#endif /* __FT6x06_H__ */
diff --git a/firmware/target/mips/ingenic_x1000/fiiom3k/button-fiiom3k.c b/firmware/target/mips/ingenic_x1000/fiiom3k/button-fiiom3k.c
index 4a853cd88f..4354257f7b 100644
--- a/firmware/target/mips/ingenic_x1000/fiiom3k/button-fiiom3k.c
+++ b/firmware/target/mips/ingenic_x1000/fiiom3k/button-fiiom3k.c
@@ -25,7 +25,9 @@
 #include "powermgmt.h"
 #include "panic.h"
 #include "axp-pmu.h"
+#include "ft6x06.h"
 #include "gpio-x1000.h"
+#include "irq-x1000.h"
 #include "i2c-x1000.h"
 #include <string.h>
 #include <stdbool.h>
@@ -35,12 +37,6 @@
 # include "font.h"
 #endif
 
-/* Touch event types */
-#define EVENT_NONE      (-1)
-#define EVENT_PRESS     0
-#define EVENT_RELEASE   1
-#define EVENT_CONTACT   2
-
 /* FSM states */
 #define STATE_IDLE          0
 #define STATE_PRESS         1
@@ -66,17 +62,6 @@
 /* Number of touch samples to smooth before reading */
 #define TOUCH_SAMPLES   3
 
-static struct ft_driver {
-    int i2c_cookie;
-    i2c_descriptor i2c_desc;
-    uint8_t raw_data[6];
-    bool active;
-
-    /* Number of pixels squared which must be moved before
-     * a scrollbar pulse is generated */
-    int scroll_thresh_sqr;
-} ftd;
-
 static struct ft_state_machine {
     /* Current button state, used by button_read_device() */
     int buttons;
@@ -105,6 +90,12 @@ static struct ft_state_machine {
 
     /* Current touch position */
     int cur_x, cur_y;
+
+    /* Motion threshold squared, in 'pixels', required to trigger scrolling */
+    int scroll_thresh_sqr;
+
+    /* Touchpad enabled state */
+    bool active;
 } fsm;
 
 /* coordinates below this are the left hand buttons,
@@ -210,9 +201,9 @@ static void ft_start_report_or_scroll(void)
 static void ft_step_state(uint32_t t, int evt, int tx, int ty)
 {
     /* Generate a release event automatically in case we missed it */
-    if(evt == EVENT_NONE) {
+    if(evt == FT6x06_EVT_NONE) {
         if(TICKS_SINCE(t, fsm.last_event_t) >= AUTORELEASE_TIME) {
-            evt = EVENT_RELEASE;
+            evt = FT6x06_EVT_RELEASE;
             tx = fsm.cur_x;
             ty = fsm.cur_y;
         }
@@ -220,7 +211,7 @@ static void ft_step_state(uint32_t t, int evt, int tx, int ty)
 
     switch(fsm.state) {
     case STATE_IDLE: {
-        if(evt == EVENT_PRESS || evt == EVENT_CONTACT) {
+        if(evt == FT6x06_EVT_PRESS || evt == FT6x06_EVT_CONTACT) {
             /* Move to REPORT or PRESS state */
             if(ft_accum_touch(t, tx, ty))
                 ft_start_report_or_scroll();
@@ -230,10 +221,10 @@ static void ft_step_state(uint32_t t, int evt, int tx, int ty)
     } break;
 
     case STATE_PRESS: {
-        if(evt == EVENT_RELEASE) {
+        if(evt == FT6x06_EVT_RELEASE) {
             /* Ignore if the number of samples is too low */
             ft_go_idle();
-        } else if(evt == EVENT_PRESS || evt == EVENT_CONTACT) {
+        } else if(evt == FT6x06_EVT_PRESS || evt == FT6x06_EVT_CONTACT) {
             /* Accumulate the touch position in the filter */
             if(ft_accum_touch(t, tx, ty))
                 ft_start_report_or_scroll();
@@ -241,14 +232,14 @@ static void ft_step_state(uint32_t t, int evt, int tx, int ty)
     } break;
 
     case STATE_REPORT: {
-        if(evt == EVENT_RELEASE)
+        if(evt == FT6x06_EVT_RELEASE)
             ft_go_idle();
-        else if(evt == EVENT_PRESS || evt == EVENT_CONTACT)
+        else if(evt == FT6x06_EVT_PRESS || evt == FT6x06_EVT_CONTACT)
             ft_accum_touch(t, tx, ty);
     } break;
 
     case STATE_SCROLL_PRESS: {
-        if(evt == EVENT_RELEASE) {
+        if(evt == FT6x06_EVT_RELEASE) {
             /* This _should_ synthesize a button press.
              *
              * - ft_start_report() will set the button bit based on the
@@ -257,10 +248,10 @@ static void ft_step_state(uint32_t t, int evt, int tx, int ty)
              *
              * - The next button_read_device() will see the button bit
              *   and report it back to Rockbox, then step the FSM with
-             *   EVENT_NONE.
+             *   FT6x06_EVT_NONE.
              *
-             * - The EVENT_NONE stepping will eventually autogenerate a
-             *   RELEASE event and restore the button state back to 0
+             * - The FT6x06_EVT_NONE stepping will eventually autogenerate
+             *   a RELEASE event and restore the button state back to 0
              *
              * - There's a small logic hole in the REPORT state which
              *   could cause it to miss an immediately repeated PRESS
@@ -271,7 +262,7 @@ static void ft_step_state(uint32_t t, int evt, int tx, int ty)
             break;
         }
 
-        if(evt == EVENT_PRESS || evt == EVENT_CONTACT)
+        if(evt == FT6x06_EVT_PRESS || evt == FT6x06_EVT_CONTACT)
             ft_accum_touch(t, tx, ty);
 
         int dx = fsm.cur_x - fsm.orig_x;
@@ -289,21 +280,21 @@ static void ft_step_state(uint32_t t, int evt, int tx, int ty)
     } break;
 
     case STATE_SCROLLING: {
-        if(evt == EVENT_RELEASE) {
+        if(evt == FT6x06_EVT_RELEASE) {
             ft_go_idle();
             break;
         }
 
-        if(evt == EVENT_PRESS || evt == EVENT_CONTACT)
+        if(evt == FT6x06_EVT_PRESS || evt == FT6x06_EVT_CONTACT)
             ft_accum_touch(t, tx, ty);
 
         int dx = fsm.cur_x - fsm.orig_x;
         int dy = fsm.cur_y - fsm.orig_y;
         int dp = (dx*dx) + (dy*dy);
-        if(dp >= ftd.scroll_thresh_sqr) {
+        if(dp >= fsm.scroll_thresh_sqr) {
             /* avoid generating events if we're supposed to be inactive...
              * should not be necessary but better to be safe. */
-            if(ftd.active) {
+            if(fsm.active) {
                 if(dy < 0) {
                     queue_post(&button_queue, BUTTON_SCROLL_BACK, 0);
                 } else {
@@ -327,18 +318,8 @@ static void ft_step_state(uint32_t t, int evt, int tx, int ty)
     }
 }
 
-static void ft_i2c_callback(int status, i2c_descriptor* desc)
+static void ft_event_cb(int evt, int tx, int ty)
 {
-    (void)desc;
-    if(status != I2C_STATUS_OK)
-        return;
-
-    /* The panel is oriented such that its X axis is vertical,
-     * so swap the axes for reporting */
-    int evt = ftd.raw_data[1] >> 6;
-    int ty = ftd.raw_data[2] | ((ftd.raw_data[1] & 0xf) << 8);
-    int tx = ftd.raw_data[4] | ((ftd.raw_data[3] & 0xf) << 8);
-
     /* TODO: convert the touch positions to linear positions.
      *
      * Points reported by the touch controller are distorted and non-linear,
@@ -346,36 +327,11 @@ static void ft_i2c_callback(int status, i2c_descriptor* desc)
      * the middle of the touchpad than on the edges, so scrolling feels slow
      * in the middle and faster near the edge.
      */
-
     ft_step_state(__ost_read32(), evt, tx, ty);
 }
 
-/* ft6x06 interrupt pin */
-void GPIOB12(void)
-{
-    /* We don't care if this fails */
-    i2c_async_queue(FT6x06_BUS, TIMEOUT_NOBLOCK, I2C_Q_ONCE,
-                    ftd.i2c_cookie, &ftd.i2c_desc);
-}
-
 static void ft_init(void)
 {
-    /* Initialize the driver state */
-    ftd.i2c_cookie = i2c_async_reserve_cookies(FT6x06_BUS, 1);
-    ftd.i2c_desc.slave_addr = FT6x06_ADDR;
-    ftd.i2c_desc.bus_cond   = I2C_START | I2C_STOP;
-    ftd.i2c_desc.tran_mode  = I2C_READ;
-    ftd.i2c_desc.buffer[0]  = &ftd.raw_data[5];
-    ftd.i2c_desc.count[0]   = 1;
-    ftd.i2c_desc.buffer[1]  = &ftd.raw_data[0];
-    ftd.i2c_desc.count[1]   = 5;
-    ftd.i2c_desc.callback   = ft_i2c_callback;
-    ftd.i2c_desc.arg        = 0;
-    ftd.i2c_desc.next       = NULL;
-    ftd.raw_data[5] = 0x02;
-    ftd.active = true;
-    touchpad_set_sensitivity(DEFAULT_TOUCHPAD_SENSITIVITY_SETTING);
-
     /* Initialize the state machine */
     fsm.buttons = 0;
     fsm.state = STATE_IDLE;
@@ -385,16 +341,24 @@ static void ft_init(void)
     fsm.sum_x = fsm.sum_y = 0;
     fsm.orig_x = fsm.orig_y = 0;
     fsm.cur_x = fsm.cur_y = 0;
+    fsm.active = true;
+    touchpad_set_sensitivity(DEFAULT_TOUCHPAD_SENSITIVITY_SETTING);
 
     /* Bring up I2C bus */
     i2c_x1000_set_freq(FT6x06_BUS, I2C_FREQ_400K);
 
+    /* Driver init */
+    ft6x06_init();
+    ft6x06_set_event_cb(ft_event_cb);
+
     /* Reset chip */
     gpio_set_level(GPIO_FT6x06_RESET, 0);
     mdelay(5);
     gpio_set_level(GPIO_FT6x06_RESET, 1);
 
     /* Configure the interrupt pin */
+    system_set_irq_handler(GPIO_TO_IRQ(GPIO_FT6x06_INTERRUPT),
+                           ft6x06_irq_handler);
     gpio_set_function(GPIO_FT6x06_INTERRUPT, GPIOF_IRQ_EDGE(0));
     gpio_enable_irq(GPIO_FT6x06_INTERRUPT);
 }
@@ -403,13 +367,13 @@ void touchpad_set_sensitivity(int level)
 {
     int pixels = 40;
     pixels -= level;
-    ftd.scroll_thresh_sqr = pixels * pixels;
+    fsm.scroll_thresh_sqr = pixels * pixels;
 }
 
 void touchpad_enable_device(bool en)
 {
-    i2c_reg_write1(FT6x06_BUS, FT6x06_ADDR, 0xa5, en ? 0 : 3);
-    ftd.active = en;
+    ft6x06_enable(en);
+    fsm.active = en;
 }
 
 /* Value of headphone detect register */
@@ -467,7 +431,7 @@ void button_init_device(void)
 int button_read_device(void)
 {
     int r = fsm.buttons;
-    ft_step_state(__ost_read32(), EVENT_NONE, 0, 0);
+    ft_step_state(__ost_read32(), FT6x06_EVT_NONE, 0, 0);
 
     /* Read GPIOs for physical buttons */
     uint32_t a = REG_GPIO_PIN(GPIO_A);