atusb/fw: new request ATUSB_GPIO for direct GPIO access

reset_rf now resets all GPIOs to their default state. This way, we
can easily recover from an incomplete or incorrect use of ATUSB_GPIO.

- atusb.c (main), board.c (reset_rf): moved call to spi_init into
  reset_rf
- board.c (reset_rf, board_init): moved GPIO setup to reset_rf
- board.c (reset_rf): set GPIOs to reset defaults
- board.h (gpio), board.c: read/modify/write all settings of GPIO
  ports
- include/atusb/ep0.h (enum atspi_requests): added new request
  ATUSB_GPIO
- ep0.c (my_setup): ATUSB_GPIO reads/reconfigures a GPIO port

atusb/fw/atusb.c

@@ -26,7 +26,6 @@
 int main(void)
 {
 	board_init();
-	spi_init();
 	reset_rf();
 
 	user_get_descriptor = sernum_get_descr;

atusb/fw/board.c

@@ -53,6 +53,21 @@ static void set_clkm(void)
 
 void reset_rf(void)
 {
+	/* set up all the outputs; default port value is 0 */
+
+	DDRB = 0;
+	DDRC = 0;
+	DDRD = 0;
+	PORTB = 0;
+	PORTC = 0;
+	PORTD = 0;
+
+	OUT(LED);
+	OUT(nRST_RF);   /* this also resets the transceiver */
+	OUT(SLP_TR);
+
+	spi_init();
+
 	/* AT86RF231 data sheet, 12.4.13, reset pulse width: 625 ns (min) */
 
 	CLR(nRST_RF);
@@ -151,6 +166,40 @@ static void get_sernum(void)
 }
 
 
+int gpio(uint8_t port, uint8_t data, uint8_t dir, uint8_t mask, uint8_t *res)
+{
+	switch (port) {
+	case 1:
+		DDRB = (DDRB & ~mask) | dir;
+		PORTB = (PORTB & ~mask) | data;
+		_delay_ms(1);
+		res[0] = PINB;
+		res[1] = PORTB;
+		res[2] = DDRB;
+		break;
+	case 2:
+		DDRC = (DDRC & ~mask) | dir;
+		PORTC = (PORTC & ~mask) | data;
+		_delay_ms(1);
+		res[0] = PINC;
+		res[1] = PORTC;
+		res[2] = DDRC;
+		break;
+	case 3:
+		DDRD = (DDRD & ~mask) | dir;
+		PORTD = (PORTD & ~mask) | data;
+		_delay_ms(1);
+		res[0] = PIND;
+		res[1] = PORTD;
+		res[2] = DDRD;
+		break;
+	default:
+		return 0;
+	}
+	return 1;
+}
+
+
 void board_init(void)
 {
 	/* Disable the watchdog timer */
@@ -165,12 +214,6 @@ void board_init(void)
 	CLKPR = 1 << CLKPCE;
 	CLKPR = 0;
 
-	/* set up all the outputs; default port value is 0 */
-
-	OUT(LED);
-	OUT(nRST_RF);   /* this also resets the transceiver */
-	OUT(SLP_TR);
-
 	/* configure timer 1 as a free-running CLK counter */
 
 	TCCR1A = 0;

atusb/fw/board.h

@@ -77,6 +77,8 @@ void panic(void);
 void timer_poll(void);
 uint64_t timer_read(void);
 
+int gpio(uint8_t port, uint8_t data, uint8_t dir, uint8_t mask, uint8_t *res);
+
 void board_init(void);
 
 #endif /* !BOARD_H */

atusb/fw/ep0.c

@@ -113,6 +113,16 @@ static int my_setup(const struct setup_request *setup)
 		usb_send(&eps[0], buf, size, NULL, NULL);
 		return 1;
 
+	case ATUSB_FROM_DEV(ATUSB_GPIO):
+		debug("ATUSB_GPIO\n");
+		if (setup->wLength < 3)
+			return 0;
+		if (!gpio(setup->wIndex, setup->wValue, setup->wValue >> 8,
+		    setup->wIndex >> 8, buf))
+			return 0;
+		usb_send(&eps[0], buf, 3, NULL, NULL);
+		return 1;
+
 	case ATUSB_TO_DEV(ATUSB_REG_WRITE):
 		debug("ATUSB_REG_WRITE\n");
 		spi_begin();

atusb/fw/include/atusb/ep0.h

@@ -25,6 +25,7 @@
  * ->host	ATUSB_POLL_INT		-		-	1
  * host->	ATUSB_TEST		-		-	0
  * ->host	ATUSB_TIMER		-		-	#bytes (6)
+ * ->host	ATUSB_GPIO		dir+data	mask+p#	3
  *
  * host->	ATUSB_REG_WRITE		value		addr	0
  * ->host	ATUSB_REG_READ		-		addr	1
@@ -72,6 +73,7 @@ enum atspi_requests {
 	ATUSB_POLL_INT,
 	ATUSB_TEST,			/* atusb-sil only */
 	ATUSB_TIMER,
+	ATUSB_GPIO,
 	ATUSB_REG_WRITE			= 0x20,	/* transceiver group */
 	ATUSB_REG_READ,
 	ATUSB_BUF_WRITE,