rockbox/firmware/target/mips/ingenic_x1000/fiiom3k/button-fiiom3k.c

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/***************************************************************************
* __________ __ ___.
* 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 "button.h"
#include "kernel.h"
#include "backlight.h"
#include "panic.h"
#include "lcd.h"
#include "gpio-x1000.h"
#include "i2c-x1000.h"
#include <string.h>
#include <stdbool.h>
#ifndef BOOTLOADER
# include "font.h"
#endif
#define FT_RST_PIN (1 << 15)
#define FT_INT_PIN (1 << 12)
#define ft_interrupt GPIOB12
/* 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
#define STATE_REPORT 2
#define STATE_SCROLL_PRESS 3
#define STATE_SCROLLING 4
/* Assume there's no active touch if no event is reported in this time */
#define AUTORELEASE_TIME (10000 * OST_TICKS_PER_US)
/* If there's no significant motion on the scrollbar for this time,
* then report it as a button press instead */
#define SCROLL_PRESS_TIME (100000 * OST_TICKS_PER_US)
/* If a press on the scrollbar moves more than this during SCROLL_PRESS_TIME,
* then we enter scrolling mode. */
#define MIN_SCROLL_THRESH 15
/* If OST tick a is after OST tick b, then returns the number of ticks
* in the interval between a and b; otherwise undefined. */
#define TICKS_SINCE(a, b) ((a) - (b))
/* 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;
/* FSM state */
int state;
/* Time of the last touch event, as 32-bit OST timestamp. The kernel
* tick is simply too low-resolution to work reliably, especially as
* we handle touchpad events asynchronously. */
uint32_t last_event_t;
/* Time of entering the SCROLL_PRESS state, used to differentiate
* between a press, hold, or scrolling motion */
uint32_t scroll_press_t;
/* Number of CONTACT events sampled in the PRESS state.
* Must reach TOUCH_SAMPLES before we move forward. */
int samples;
/* Filter for smoothing touch points */
int sum_x, sum_y;
/* Position of the original touch */
int orig_x, orig_y;
/* Current touch position */
int cur_x, cur_y;
} fsm;
static int touch_to_button(int x, int y)
{
if(x == 900) {
/* Right strip */
if(y == 80)
return BUTTON_BACK;
else if(y == 240)
return BUTTON_RIGHT;
else
return 0;
} else if(x < 80) {
/* Left strip */
if(y < 80)
return BUTTON_MENU;
else if(y > 190)
return BUTTON_LEFT;
else
return 0;
} else {
/* Middle strip */
if(y < 100)
return BUTTON_UP;
else if(y > 220)
return BUTTON_DOWN;
else
return BUTTON_SELECT;
}
}
static bool ft_accum_touch(uint32_t t, int tx, int ty)
{
/* Record event time */
fsm.last_event_t = t;
if(fsm.samples < TOUCH_SAMPLES) {
/* Continue "priming" the filter */
fsm.sum_x += tx;
fsm.sum_y += ty;
fsm.samples += 1;
/* Return if filter is not ready */
if(fsm.samples < TOUCH_SAMPLES)
return false;
} else {
/* Update filter */
fsm.sum_x += tx - fsm.sum_x / TOUCH_SAMPLES;
fsm.sum_y += ty - fsm.sum_y / TOUCH_SAMPLES;
}
/* Filter is ready, so read the point */
fsm.cur_x = fsm.sum_x / TOUCH_SAMPLES;
fsm.cur_y = fsm.sum_y / TOUCH_SAMPLES;
return true;
}
static void ft_go_idle(void)
{
/* Null out the touch state */
fsm.buttons = 0;
fsm.samples = 0;
fsm.sum_x = fsm.sum_y = 0;
fsm.state = STATE_IDLE;
}
static void ft_start_report(void)
{
/* Report the button bit */
fsm.buttons = touch_to_button(fsm.cur_x, fsm.cur_y);
fsm.orig_x = fsm.cur_x;
fsm.orig_y = fsm.cur_y;
fsm.state = STATE_REPORT;
}
static void ft_start_report_or_scroll(void)
{
ft_start_report();
/* If the press occurs on the scrollbar, then we need to
* wait an additional delay before reporting it in case
* this is the beginning of a scrolling motion */
if(fsm.buttons & (BUTTON_UP|BUTTON_DOWN|BUTTON_SELECT)) {
fsm.buttons = 0;
fsm.scroll_press_t = __ost_read32();
fsm.state = STATE_SCROLL_PRESS;
}
}
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(TICKS_SINCE(t, fsm.last_event_t) >= AUTORELEASE_TIME) {
evt = EVENT_RELEASE;
tx = fsm.cur_x;
ty = fsm.cur_y;
}
}
switch(fsm.state) {
case STATE_IDLE: {
if(evt == EVENT_PRESS || evt == EVENT_CONTACT) {
/* Move to REPORT or PRESS state */
if(ft_accum_touch(t, tx, ty))
ft_start_report_or_scroll();
else
fsm.state = STATE_PRESS;
}
} break;
case STATE_PRESS: {
if(evt == EVENT_RELEASE) {
/* Ignore if the number of samples is too low */
ft_go_idle();
} else if(evt == EVENT_PRESS || evt == EVENT_CONTACT) {
/* Accumulate the touch position in the filter */
if(ft_accum_touch(t, tx, ty))
ft_start_report_or_scroll();
}
} break;
case STATE_REPORT: {
if(evt == EVENT_RELEASE)
ft_go_idle();
else if(evt == EVENT_PRESS || evt == EVENT_CONTACT)
ft_accum_touch(t, tx, ty);
} break;
case STATE_SCROLL_PRESS: {
if(evt == EVENT_RELEASE) {
/* This _should_ synthesize a button press.
*
* - ft_start_report() will set the button bit based on the
* current touch position and enter the REPORT state, which
* will automatically hold the bit high
*
* - The next button_read_device() will see the button bit
* and report it back to Rockbox, then step the FSM with
* EVENT_NONE.
*
* - The EVENT_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
* that occurs before the autorelease timeout kicks in.
* FIXME: We might want to special-case that.
*/
ft_start_report();
break;
}
if(evt == EVENT_PRESS || evt == EVENT_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 >= MIN_SCROLL_THRESH*MIN_SCROLL_THRESH) {
/* Significant motion: enter SCROLLING state */
fsm.state = STATE_SCROLLING;
} else if(TICKS_SINCE(t, fsm.scroll_press_t) >= SCROLL_PRESS_TIME) {
/* No significant motion: report it as a press */
fsm.cur_x = fsm.orig_x;
fsm.cur_y = fsm.orig_y;
ft_start_report();
}
} break;
case STATE_SCROLLING: {
if(evt == EVENT_RELEASE) {
ft_go_idle();
break;
}
if(evt == EVENT_PRESS || evt == EVENT_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(dy < 0) {
queue_post(&button_queue, BUTTON_SCROLL_BACK, 0);
} else {
queue_post(&button_queue, BUTTON_SCROLL_FWD, 0);
}
/* Poke the backlight */
backlight_on();
buttonlight_on();
fsm.orig_x = fsm.cur_x;
fsm.orig_y = fsm.cur_y;
}
} break;
default:
panicf("ft6x06: unhandled state");
break;
}
}
static void ft_i2c_callback(int status, i2c_descriptor* desc)
{
(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,
* ideally we'd like to correct these values. There's more precision in
* 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);
}
void ft_interrupt(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;
fsm.last_event_t = 0;
fsm.scroll_press_t = 0;
fsm.samples = 0;
fsm.sum_x = fsm.sum_y = 0;
fsm.orig_x = fsm.orig_y = 0;
fsm.cur_x = fsm.cur_y = 0;
/* Bring up I2C bus */
i2c_x1000_set_freq(FT6x06_BUS, I2C_FREQ_400K);
/* Reset chip */
gpio_config(GPIO_B, FT_RST_PIN|FT_INT_PIN, GPIO_OUTPUT(0));
mdelay(5);
gpio_out_level(GPIO_B, FT_RST_PIN, 1);
gpio_config(GPIO_B, FT_INT_PIN, GPIO_IRQ_EDGE(0));
gpio_enable_irq(GPIO_B, FT_INT_PIN);
}
void touchpad_set_sensitivity(int level)
{
int pixels = 40;
pixels -= level;
ftd.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;
}
/* Value of headphone detect register */
static uint8_t hp_detect_reg = 0x00;
/* Interval to poll the register */
#define HPD_POLL_TIME (HZ/2)
static int hp_detect_tmo_cb(struct timeout* tmo)
{
i2c_descriptor* d = (i2c_descriptor*)tmo->data;
i2c_async_queue(AXP173_BUS, TIMEOUT_NOBLOCK, I2C_Q_ADD, 0, d);
return HPD_POLL_TIME;
}
static void hp_detect_init(void)
{
static struct timeout tmo;
static const uint8_t gpio_reg = 0x94;
static i2c_descriptor desc = {
.slave_addr = AXP173_ADDR,
.bus_cond = I2C_START | I2C_STOP,
.tran_mode = I2C_READ,
.buffer[0] = (void*)&gpio_reg,
.count[0] = 1,
.buffer[1] = &hp_detect_reg,
.count[1] = 1,
.callback = NULL,
.arg = 0,
.next = NULL,
};
/* Headphone detect is wired to an undocumented GPIO on the AXP173.
* This sets it to input mode so we can see the pin state. */
i2c_reg_write1(AXP173_BUS, AXP173_ADDR, 0x93, 0x01);
/* Get an initial reading before startup */
int r = i2c_reg_read1(AXP173_BUS, AXP173_ADDR, gpio_reg);
if(r >= 0)
hp_detect_reg = r;
/* Poll the register every second */
timeout_register(&tmo, &hp_detect_tmo_cb, HPD_POLL_TIME, (intptr_t)&desc);
}
/* Rockbox interface */
void button_init_device(void)
{
/* Configure physical button GPIOs */
gpio_config(GPIO_A, (1 << 17) | (1 << 19), GPIO_INPUT);
gpio_config(GPIO_B, (1 << 28) | (1 << 31), GPIO_INPUT);
/* Initialize touchpad */
ft_init();
/* Set up headphone detect polling */
hp_detect_init();
}
int button_read_device(void)
{
int r = fsm.buttons;
ft_step_state(__ost_read32(), EVENT_NONE, 0, 0);
/* Read GPIOs for physical buttons */
uint32_t a = REG_GPIO_PIN(GPIO_A);
uint32_t b = REG_GPIO_PIN(GPIO_B);
/* All buttons are active low */
if((a & (1 << 17)) == 0) r |= BUTTON_PLAY;
if((a & (1 << 19)) == 0) r |= BUTTON_VOL_UP;
if((b & (1 << 28)) == 0) r |= BUTTON_VOL_DOWN;
if((b & (1 << 31)) == 0) r |= BUTTON_POWER;
return r;
}
bool headphones_inserted()
{
return hp_detect_reg & 0x40 ? true : false;
}
#ifndef BOOTLOADER
static int getbtn(void)
{
int btn;
do {
btn = button_get_w_tmo(1);
} while(btn & (BUTTON_REL|BUTTON_REPEAT));
return btn;
}
bool dbg_fiiom3k_touchpad(void)
{
static const char* fsm_statenames[] = {
"IDLE", "PRESS", "REPORT", "SCROLL_PRESS", "SCROLLING"
};
do {
int line = 0;
lcd_clear_display();
lcd_putsf(0, line++, "state: %s", fsm_statenames[fsm.state]);
lcd_putsf(0, line++, "button: %08x", fsm.buttons);
lcd_putsf(0, line++, "pos x: %4d orig x: %4d", fsm.cur_x, fsm.orig_x);
lcd_putsf(0, line++, "pos y: %4d orig y: %4d", fsm.cur_y, fsm.orig_y);
lcd_update();
} while(getbtn() != BUTTON_POWER);
return false;
}
#endif