add N3DS EXTHID driver #3
Conversation
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Device 17 is a bit of a cryptic name. I remember that nocash called it IO expander somewhere which is a bit better but still not sure. https://problemkaputt.de/gbatek-3ds-i2c-new3ds-c-stick-and-zl-zr-buttons.htm |
100% agree that it's a cryptic name but I have no idea what to call it. Any suggestion? nocash mentioned IO expander but not for this one, it was for another device , I think it was the QTM |
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Hmm, it seems to be this chip on the A/B/X/Y board i guess. Literally no datasheet. https://de.ifixit.com/Teardown/Nintendo+3DS+XL+2015+Teardown/36346?utm_term=Teardown#s81199 As for ideas got a few from the GodMode9 Discord/IRC. N3DS_EXTHID for example. |
I got some clues that it might be this chip https://gbatemp.net/attachments/rbvaefc22h6aixqgaas6sohprly388_edit-jpg.198252/ I think nocash also mentioned this. HF374 7NU9 But your link mentioning it's a strain gauge sensor is something I totally miss! Let me try some more digging. In the mean time I'll call it Also, the real ir:rst service actually has some init code that includes sending some i2c command. Probably some setting for sensitivity / resolution. I'll try to dig more for the datasheet. |
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updated name to N3DS_EXTHID in e80c04b |
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I will do some experiments before i merge this or add changes. Something i definitely want to change is making this IRQ driven because bigger I2C reads every frame are not good. They are simply too slow. That chip is apparently connected to a GPIO and sends signals every time data is ready for read. Also i will merge the I2C start functions to de-duplicate a bit of code. |
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I was able to get GPIO interrupt working, but I'm hesitant to put it here, seems there's conflict with I was quite confused when at first I tried to register the ISR and just expects it to work, but it never fired. Turns out I was missing call to On the subject of i2c, could you also add this? bool I2C_writeCommand(const I2cDevice devId, const u8 command)
{
const u8 devAddr = g_i2cDevTable[devId].devAddr;
const I2cState *const state = &g_i2cState[g_i2cDevTable[devId].busId];
I2cBus *const i2cBus = state->i2cBus;
const KHandle event = state->event;
const KHandle mutex = state->mutex;
lockMutex(mutex);
if(i2cBus->cnt & I2C_EN) waitForEvent(event);
clearEvent(event);
// Select device and start.
sendByte(i2cBus, devAddr, I2C_START, event);
if(!checkAck(i2cBus))
{
unlockMutex(mutex);
return false;
}
sendByte(i2cBus, command, I2C_STOP, event);
if(!checkAck(i2cBus))
{
unlockMutex(mutex);
return false;
}
unlockMutex(mutex);
return true;
}It's not used at the moment, and ZL & ZR works fine without it. I think the C-stick is not too sensitive without some more configuration, even though it works without configuration. This should correspond to WriteCommand8 |
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This is what i came up with in the meantime after looking how ir module interfaces with this chip. Some code isn't ever taken with the hardcoded values. It was a test anyway. And it needs some I2C and GPIO driver changes i did. As for the GPIO conflict we can easily solve this because the depop GPIO is actually only used on old 3DS in codec module. static u8 g_extHidRev = 0;
static bool EXTHID_command(const u8 cmd)
{
return I2C_writeReg(I2C_DEV_N3DS_HID, 0xFFFFFFFF, cmd);
}
static bool EXTHID_read5(void *buf)
{
return I2C_readRegArray(I2C_DEV_N3DS_HID, 0xFFFFFFFF, buf, 5);
}
static bool exthidSleep(void)
{
bool res;
if(g_extHidRev == 2)
{
// Some kind of bug fix for revision 2?
res = EXTHID_command(0x30u | 7);
if(!res) return res;
}
// Disable output.
res = EXTHID_command(0xF7);
if(!res) return res;
TIMER_sleepMs(6); // \ Is this yet another bug fix?
u8 unused[5]; // |
res = EXTHID_read5(unused); // /
if(!res) return res;
// Changes Which GPIO bits are copied to the regs? Prevents the chip from waking up with ZL/ZR?
res = EXTHID_command(0x7C);
if(!res) return res;
// Sleep command with auto calibration?
return EXTHID_command(0xD0);
}
static void exthidWakeChip(void)
{
// Triggers an IRQ to wake the chip up?
GPIO_write(GPIO_EXTHID_WAKE, 0);
TIMER_sleepUs(100);
GPIO_write(GPIO_EXTHID_WAKE, 1);
TIMER_sleepMs(10);
}
static bool exthidWakeup(void)
{
exthidWakeChip();
// Changes which GPIO bits are copied to the regs again?
bool res = EXTHID_command(0x7F);
if(!res) return res;
// Calibration really takes that long?
TIMER_sleepMs(136);
// Enable output.
res = EXTHID_command(0xF9);
if(!res) return res;
if(g_extHidRev == 2)
{
// Revert bug fix on wakeup?
res = EXTHID_command(0x30u | 3);
}
return res;
}
static bool EXTHID_init(void)
{
// External EXTHID IRQ to wake the chip up?
GPIO_config(GPIO_EXTHID_WAKE, GPIO_OUTPUT);
GPIO_write(GPIO_EXTHID_WAKE, 1);
// -----------------------------
// Set device mode.
bool res = EXTHID_command(0xC1); // Selects an ADC curve or something?
if(!res) return res;
res = EXTHID_command(0x52); // Changes conversion mode?
if(!res) return res;
// Disable output.
res = EXTHID_command(0xF7); // Disables output GPIOs or something?
if(!res) return res;
// Get device ID.
struct
{
u8 status;
u8 vendor;
u8 rev;
u8 reserved;
u8 stopByte;
} devId;
res = EXTHID_command(0xF5);
if(!res) return res;
TIMER_sleepMs(2); // wtf, why is this needed?
res = EXTHID_read5(&devId);
if(!res) return res;
g_extHidRev = devId.rev;
ee_printf("Dev ID: %" PRIX8 ", %" PRIX8 ", %" PRIX8 ", %" PRIX8 ", %" PRIX8 "\n",
devId.status, devId.vendor, devId.rev, devId.reserved, devId.stopByte);
if(devId.status != 0x82 || devId.stopByte != 0xFF)
return false;
// TODO: ir module does skip all of the following code except sleep() if vendor is not 1.
if(devId.rev >= 1)
{
// Set sensitivity to 1.0. Only works with the mode set above.
res = EXTHID_command(0x08); // Command 0x08-0x0F. 1.0-1.875. In 0.125 steps.
if(!res) return res;
// Disable idle state.
res = EXTHID_command(0xF3);
if(!res) return res;
// -----------------------------
const u8 calThreshold = 30;
if(true)
{
if(calThreshold == 0)
{
res = EXTHID_command(0xF1); // Automatic calibration?
}
else
{
res = EXTHID_command(0xF2); // Automatic calibration again but with thresholds?
}
}
else
{
res = EXTHID_command(0xF0); // Automatic calibration disable?
}
if(!res) return res;
if(calThreshold > 0)
{
// Set auto calibration threshold. TODO: Can be merged with above code.
// Auto calibration threshold? 0-0xF. Note: There is a lookup table.
res = EXTHID_command(0x20u | 0x9);
if(!res) return res;
}
const u8 opThreshold = 5; // Valid values: 1-16.
res = EXTHID_command(0x80u | ((opThreshold - 1) & 0xFu));
if(!res) return res;
const u8 outThreshold = 7; // Valid values: 2-16.
res = EXTHID_command(0x90u | ((outThreshold - 1) & 0xFu));
if(!res) return res;
// TODO: Lookup table for op timer values.
//const u8 opTimer = 21;
res = EXTHID_command(0xB0u | 0x4);
if(!res) return res;
// TODO: Lookup table for out timer values.
//const u8 outTimer = 9;
res = EXTHID_command(0x60u | 0x3);
if(!res) return res;
// -----------------------------
}
if(devId.rev >= 2)
{
res = EXTHID_command(0x30u | 0x3); // Command 0x30-0x37.
if(!res) return res;
}
return exthidSleep();
}
static bool exthidSetSamplePeriod(const u32 period)
{
if(period < 10 || period > 21) return false;
if(!EXTHID_command(0xA0u | ((period - 10) & 0xFu))) return false;
TIMER_sleepMs(56); // bruh
return true;
}
static KHandle g_extHidEvent = 0;
static void exthidIsr(UNUSED u32 intSource)
{
signalEvent(g_extHidEvent, false);
}
// Note: libctru uses a default period of 10.
static bool EXTHID_startSampling(const u32 period)
{
GPIO_config(GPIO_EXTHID_IRQ, GPIO_IRQ_FALLING | GPIO_INPUT);
IRQ_registerIsr(IRQ_GPIO_3_0, 13, 0, exthidIsr);
g_extHidEvent = createEvent(true);
if(!exthidWakeup()) return false;
return exthidSetSamplePeriod(period);
}
static bool EXTHID_stopSampling(void)
{
if(!exthidSleep()) return false;
// Note: Nintendo does a weird sequence of GPIO changes here.
// In order:
// Disable GPIO IRQ (not ARM11 side IRQ).
// Change to falling edge trigger (keep IRQ disabled). This is a no-op since it's already falling edge.
// Set GPIO to output (wtf).
// Set GPIO high (wtf).
// Set GPIO to back to input.
// Then finally the event is unbound from the IRQ (disables ARM11 side IRQ).
GPIO_config(GPIO_EXTHID_IRQ, GPIO_INPUT); // Input but no IRQ.
IRQ_unregisterIsr(IRQ_GPIO_3_0);
deleteEvent(g_extHidEvent);
g_extHidEvent = 0;
return true;
}
static bool EXTHID_getRawData(void *data)
{
// Note: In polling mode we need to request data and then wait 2 ms.
return EXTHID_read5(data);
}
int main(void)
{
GFX_init(GFX_BGR8, GFX_R5G6B5, GFX_TOP_2D);
GFX_setLcdLuminance(20);
consoleInit(GFX_LCD_BOT, NULL);
//CODEC_init();
ee_printf("init res: %u\n", EXTHID_init());
ee_printf("start sampling: %u\n", EXTHID_startSampling(16));
while(1)
{
waitForEvent(g_extHidEvent);
struct
{
u8 status;
u8 gpio;
u8 x;
u8 y;
u8 stopByte;
} raw;
const bool res = EXTHID_getRawData(&raw);
ee_printf("\rres %u %" PRIX8 ", %" PRIX8 ", %" PRIu8 ", %" PRIu8 ", %" PRIX8 " ",
res, raw.status, raw.gpio, raw.x, raw.y, raw.stopByte);
//GFX_waitForVBlank0();
hidScanInput();
if(hidGetExtraKeys(0) & (KEY_POWER_HELD | KEY_POWER)) break;
}
EXTHID_stopSampling();
fUnmount(FS_DRIVE_SDMC);
CODEC_deinit();
GFX_deinit();
power_off();
return 0;
} |
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Wow that's miles ahead from what I found! Could you tell me how you figure it out? I was stuck even figuring out what the commands meant. I couldn't make sense how you'd know which parts are for the devid vendor, for example and I'd love to learn more. |
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Join the GodMode9 Discord or IRC (they are bridged). Preferably the offtopic channel. I can explain further there. In the meanwhile looks like i got X/Y data conversion working. |
Add N3DS EXTHID (device 17h) driver for getting ZL, ZR, and C-Stick for supported devices
Needed for profi200/open_agb_firm#173
Notes:
A lot of the device information is still unknown. Here's what we know so far for a fact:
Assumptions:
Images:
https://gbatemp.net/attachments/rbvaefc22h6aixqgaas6sohprly388_edit-jpg.198252/
https://gbatemp.net/attachments/4_power_ic_id_edit-jpg.198242/