temperature stuff actually working now

README.md

@@ -138,12 +138,19 @@ sensor (the exact sensor emulated is the Microchip MCP9808). To have it show
 up in `sensors`, do the following (with `BUSNUM` the number from the above
 `i2cdetect -l` output):
 ```
+$ ./dmctl.py /dev/ttyACM1 --i2ctemp 0x18     # need to give it an address first
 $ sudo modprobe jc42
+$ # now tell the jc42 module that the device can be found at this address
 $ echo "jc42 0x18" | sudo tee /sys/bus/i2c/device/i2c-BUSNUM/new_device
-$ sudo sensors
+$ sudo sensors                               # it should show up now:
+jc42-i2c-BUSNUM-18
+Adapter: i2c-tiny-usb at bus 001 device 032
+temp1:        +23.1°C  (low  = -20.0°C)
+                       (high = +75.0°C, hyst = +75.0°C)
+                       (crit = +80.0°C, hyst = +80.0°C)
 ```
 
-Temperature readout is currently not really working.
+Temperature readout may be a bit higher than the ambient temperature.
 
 ### Runtime configuration
 
@@ -156,6 +163,7 @@ The currently implemented options are:
 - `i2ctemp`: Get or set the I2C address of the fake I2C device of the temperature
              sensor. Use 0 for getting the value, 0xff for disabling, and any
              other for setting the address. The I2C device emulated is an MCP9808.
+             When setting a value, the old value is printed.
 
 ```
 usage: dmctl [-h] [-v] [--ctsrts [CTSRTS]] tty
@@ -201,7 +209,7 @@ libco is licensed under the [ISC license](https://opensource.org/licenses/ISC)
       to use the UART interface as a loopback thing.
   - [ ] Second UART port for when stdio UART is disabled?
 - [x] I2C support by emulating the I2C Tiny USB
-  - [ ] Expose RP2040-internal temperature ADC on I2C-over-USB bus?
+  - [x] Expose RP2040-internal temperature ADC on I2C-over-USB bus?
   - [ ] ~~Does SMBus stuff need special treatment here?~~ ~~No.~~  Actually, some
     parts do, but, laziness.
   - [x] 10-bit I2C address support (Needs poking at the Pico SDK, as it only

bsp/rp2040/tempsensor.c

@@ -28,9 +28,20 @@ void tempsense_dev_init(void) {
 int16_t tempsense_dev_get_temp(void) {
 	adc_select_input(4); // select temp sensor
 	uint16_t result = adc_read();
-	int temperature = float2fix(T_OFF - T_BIAS / T_SLOPE)
-		+ (int)result * float2fix(V_MAX / (D_RANGE * T_SLOPE));
 
-	return trunc_8fix4(temperature);
+	float voltage = result * (V_MAX / D_RANGE);
+
+	float tempf = T_OFF + (voltage - T_BIAS) / T_SLOPE;
+
+	// FIXME: use fixed point instead! but something's wrong with the formula below
+	/*int temperature = float2fix(T_OFF - T_BIAS / T_SLOPE)
+		+ (int)result * float2fix(V_MAX / (D_RANGE * T_SLOPE));*/
+
+	return trunc_8fix4(/*temperature*/float2fix(tempf));
 }
 
+// RP2040 absolute min/max are -20/85
+int16_t tempsense_dev_get_lower(void) { return trunc_8fix4(float2fix(-15)); }
+int16_t tempsense_dev_get_upper(void) { return trunc_8fix4(float2fix( 75)); }
+int16_t tempsense_dev_get_crit (void) { return trunc_8fix4(float2fix( 80)); }
+

src/t/.gitignore

@@ -0,0 +1 @@
+tstest

src/t/tstest.c

@@ -0,0 +1,67 @@
+
+#define DBOARD_HAS_TEMPSENSOR
+#define VERY_FAKE
+
+#include <stdint.h>
+
+static inline void tempsense_dev_init(void) { }
+static inline int16_t tempsense_dev_get_temp(void) { return 42 << 4; }
+
+static inline int16_t tempsense_dev_get_lower(void) { return  0 << 4; }
+static inline int16_t tempsense_dev_get_upper(void) { return 75 << 4; }
+static inline int16_t tempsense_dev_get_crit (void) { return 80 << 4; }
+
+#include "../tempsensor.c"
+
+static int do_pkt(uint8_t cmd, bool read, uint16_t addr, uint16_t len, uint8_t* buf) {
+	int rv;
+
+	if (cmd & 1) tempsense_do_start();
+
+	if (read) {
+		rv = tempsense_do_read(len, buf);
+	} else {
+		rv = tempsense_do_write(len, buf);
+	}
+
+	if (cmd & 2) tempsense_do_stop();
+
+	printf("-> %d: %s\n", rv, (rv < 0 || rv != len) ? "nak" : "ack");
+
+	return rv;
+}
+
+static void pbuf(size_t len, const uint8_t* buf) {
+	printf("--> ");
+	size_t i;
+	for (i = 0; i < len; ++i) {
+		printf("%02x ", buf[i]);
+		if ((i & 0xf) == 0xf) printf("%c", '\n');
+	}
+	if ((i & 0xf) != 0x0) printf("%c", '\n');
+}
+
+int main(int argc, char* argv[]) {
+	tempsense_init();
+
+	tempsense_set_addr(0x18);
+
+	// initial probe
+	uint8_t pk1[1] = {0}; do_pkt(0x05, false, 0x18, 1, pk1);
+	uint8_t pk2[2];       do_pkt(0x06, true , 0x18, 2, pk2); pbuf(2, pk2);
+
+	uint8_t pk3[1] = {1}; do_pkt(0x05, false, 0x18, 1, pk3);
+	uint8_t pk4[2];       do_pkt(0x06, true , 0x18, 2, pk4); pbuf(2, pk4);
+
+	// sensor data get
+
+	// out 0x05 cmd5
+	// in 2byte cmd6
+	// out 0x04 cmd5
+	// in 2byte cmd6
+	// out 0x03 cmd5
+	// in 2byte cmd6
+	// out 0x02 cmd5
+	// in 2byte cmd6
+}
+

src/tempsensor.c

@@ -4,7 +4,10 @@
 #include <stdbool.h>
 #include <stdio.h>
 
+#ifndef VERY_FAKE
 #include "protocfg.h"
+#define printf(fmt, ...) do{}while(0)
+#endif
 
 #ifdef DBOARD_HAS_TEMPSENSOR
 
@@ -17,7 +20,8 @@ static size_t index;
 static bool instartstop, hasreg;
 
 enum regid {
-	config = 1,
+	cap = 0,
+	config,
 	t_upper,
 	t_lower,
 	t_crit,
@@ -36,6 +40,13 @@ struct {
 	uint8_t reso;
 } mcp9808;
 
+#define float2fix(x) (int)((x)*(1<<4))
+__attribute__((__const__))
+inline static int16_t trunc_8fix4(int fix) {
+	if (fix >  4095) fix =  4095;
+	if (fix < -4096) fix = -4096;
+	return fix;
+}
 void tempsense_init(void) {
 	active = false;
 	addr = 0xff;
@@ -45,6 +56,10 @@ void tempsense_init(void) {
 	hasreg = false;
 
 	tempsense_dev_init();
+
+	mcp9808.t_lower = tempsense_dev_get_lower();
+	mcp9808.t_upper = tempsense_dev_get_upper();
+	mcp9808.t_crit  = tempsense_dev_get_crit ();
 }
 
 bool tempsense_get_active(void) { return active; }
@@ -57,16 +72,20 @@ void tempsense_set_addr(uint8_t a) {
 }
 
 void tempsense_do_start(void) {
+	printf("ts start\n");
 	//reg = 0;
 	index = 0;
 	instartstop = true;
 	hasreg = false;
 }
 void tempsense_do_stop(void) {
+	printf("ts stop\n");
 	instartstop = false;
 }
 
 int tempsense_do_read(int length, uint8_t* buf) {
+	printf("read l=%d reg=%02x ", length, reg);
+
 	if (!instartstop || length < 0) return -1; // nak
 	if (length == 0) return 0; // ack
 	//if (!hasreg) return -1; // nak
@@ -75,22 +94,29 @@ int tempsense_do_read(int length, uint8_t* buf) {
 	for (i = 0; i < length; ++i, ++index) {
 		switch (reg) {
 			// TODO: big or little endian? seems to be big
+		case cap:
+			buf[index] = 0;
+			break;
 		case config:
 			if (index == 0) buf[0] = (mcp9808.config >> 8) & 0xff;
 			else if (index == 1) buf[1] = (mcp9808.config >> 0) & 0xff;
 			else return index;
+			break;
 		case t_upper:
 			if (index == 0) buf[0] = (mcp9808.t_upper >> 8) & 0xff;
 			else if (index == 1) buf[1] = (mcp9808.t_upper >> 0) & 0xff;
 			else return index;
+			break;
 		case t_lower:
 			if (index == 0) buf[0] = (mcp9808.t_lower >> 8) & 0xff;
 			else if (index == 1) buf[1] = (mcp9808.t_lower >> 0) & 0xff;
 			else return index;
+			break;
 		case t_crit:
 			if (index == 0) buf[0] = (mcp9808.t_crit >> 8) & 0xff;
 			else if (index == 1) buf[1] = (mcp9808.t_crit >> 0) & 0xff;
 			else return index;
+			break;
 		case t_a: {
 				static uint16_t temp;
 				if (index == 0) {
@@ -113,17 +139,21 @@ int tempsense_do_read(int length, uint8_t* buf) {
 				} else if (index == 1) buf[1] = (temp>>0) & 0xff;
 				else return index;
 			}
+			break;
 		case manuf_id:
 			if (index == 0) buf[0] = (MANUF_ID >> 8) & 0xff;
 			else if (index == 1) buf[1] = (MANUF_ID>>0)&0xff;
 			else return index;
+			break;
 		case dev_idrev:
 			if (index == 0) buf[0] = (DEV_IDREV >> 8) & 0xff;
 			else if (index == 1) buf[1] = (DEV_IDREV>>0)&0xff;
 			else return index;
+			break;
 		case reso:
 			if (index == 0) buf[0] = mcp9808.reso;
 			else return index;
+			break;
 		default: return -1;
 		}
 	}
@@ -131,10 +161,14 @@ int tempsense_do_read(int length, uint8_t* buf) {
 	return i;
 }
 int tempsense_do_write(int length, const uint8_t* buf) {
+	printf("write l=%d reg=%02x iss=%c ", length, reg, instartstop?'t':'f');
+
 	if (!instartstop || length < 0) return -1; // nak
 	if (length == 0) return 0; // ack
 
 	if (!hasreg) {
+		printf("get reg %02x ", reg);
+
 		reg = *buf & 0xf;
 		++buf;
 		--length;
@@ -152,27 +186,34 @@ int tempsense_do_write(int length, const uint8_t* buf) {
 			}  else if (index == 1) {
 				mcp9808.config = (mcp9808.config & 0xff00) | ((uint16_t)buf[1] << 0);
 			} else return index;
+			break;
 		case t_upper:
 			if (index == 0) {
 				mcp9808.t_upper = (mcp9808.t_upper & 0x00ff) | ((uint16_t)buf[0] << 8);
 			} else if (index == 1) {
 				mcp9808.t_upper = (mcp9808.t_upper & 0xff00) | ((uint16_t)buf[1] << 0);
 			} else return index;
+			break;
 		case t_lower:
 			if (index == 0) {
 				mcp9808.t_lower = (mcp9808.t_lower & 0x00ff) | ((uint16_t)buf[0] << 8);
 			} else if (index == 1) {
 				mcp9808.t_lower = (mcp9808.t_lower & 0xff00) | ((uint16_t)buf[1] << 0);
 			} else return index;
+			break;
 		case t_crit:
 			if (index == 0) {
 				mcp9808.t_crit = (mcp9808.t_crit & 0x00ff) | ((uint16_t)buf[0] << 8);
 			} else if (index == 1) {
 				mcp9808.t_crit = (mcp9808.t_crit & 0xff00) | ((uint16_t)buf[1] << 0);
 			} else return index;
+			break;
 		case reso:
 			mcp9808.reso = buf[index];
-		default: return -1;
+			break;
+		default:
+			printf("unk reg\n");
+			return -1;
 		}
 	}
 

src/tempsensor.h

@@ -21,6 +21,10 @@ void tempsense_do_stop(void); // stop cond
 void tempsense_dev_init(void);
 // 8.4
 int16_t tempsense_dev_get_temp(void);
+
+int16_t tempsense_dev_get_lower(void);
+int16_t tempsense_dev_get_upper(void);
+int16_t tempsense_dev_get_crit (void);
 #endif
 
 #endif

src/vnd_i2ctinyusb.c

@@ -85,7 +85,10 @@ static bool iub_ctl_req(uint8_t rhport, uint8_t stage, tusb_control_request_t co
 #ifdef DBOARD_HAS_TEMPSENSOR
 			if (tempsense_get_active() && tempsense_get_addr() == cmd.addr) {
 				if (cmd.cmd & ITU_CMD_I2C_IO_BEGIN_F) tempsense_do_start();
-				status = tempsense_do_write(cmd.len > sizeof rxbuf ? sizeof rxbuf : cmd.len, rxbuf);
+				// FIXME: fix status handling
+				int rv = tempsense_do_write(cmd.len > sizeof rxbuf ? sizeof rxbuf : cmd.len, rxbuf);
+				if (rv < 0 || rv != cmd.len) status = ITU_STATUS_ADDR_NAK;
+				else status = ITU_STATUS_ADDR_ACK;
 				if (cmd.cmd & ITU_CMD_I2C_IO_END_F  ) tempsense_do_stop ();
 			} else
 #endif
@@ -155,7 +158,9 @@ static bool iub_ctl_req(uint8_t rhport, uint8_t stage, tusb_control_request_t co
 #ifdef DBOARD_HAS_TEMPSENSOR
 					if (tempsense_get_active() && tempsense_get_addr() == cmd.addr) {
 						if (cmd.cmd & ITU_CMD_I2C_IO_BEGIN_F) tempsense_do_start();
-						status = tempsense_do_read(cmd.len > sizeof txbuf ? sizeof txbuf : cmd.len, txbuf);
+						int rv = tempsense_do_read(cmd.len > sizeof txbuf ? sizeof txbuf : cmd.len, txbuf);
+						if (rv < 0 || rv != cmd.len) status = ITU_STATUS_ADDR_NAK;
+						else status = ITU_STATUS_ADDR_ACK;
 						if (cmd.cmd & ITU_CMD_I2C_IO_END_F  ) tempsense_do_stop ();
 					} else
 #endif
@@ -173,7 +178,9 @@ static bool iub_ctl_req(uint8_t rhport, uint8_t stage, tusb_control_request_t co
 #ifdef DBOARD_HAS_TEMPSENSOR
 						if (tempsense_get_active() && tempsense_get_addr() == cmd.addr) {
 							if (cmd.cmd & ITU_CMD_I2C_IO_BEGIN_F) tempsense_do_start();
-							status = tempsense_do_write(0, &bleh);
+							int rv = tempsense_do_write(0, &bleh);
+							if (rv < 0 || rv != cmd.len) status = ITU_STATUS_ADDR_NAK;
+							else status = ITU_STATUS_ADDR_ACK;
 							if (cmd.cmd & ITU_CMD_I2C_IO_END_F  ) tempsense_do_stop ();
 						} else
 #endif