9 files changed, 887 insertions, 0 deletions
diff --git a/src/attiny/ao_arch.h b/src/attiny/ao_arch.h
new file mode 100644
index 00000000..c34206e6
--- /dev/null
+++ b/src/attiny/ao_arch.h
@@ -0,0 +1,82 @@
+/*
+ * Copyright © 2011 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef _AO_ARCH_H_
+#define _AO_ARCH_H_
+
+#include <stdio.h>
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/sleep.h>
+
+#define F_CPU  8000000UL	// 8 MHz
+
+/*
+ * AVR definitions and code fragments for AltOS
+ */
+
+#define AO_STACK_SIZE	116
+
+/* Various definitions to make GCC look more like SDCC */
+
+#define ao_arch_naked_declare	__attribute__((naked))
+#define ao_arch_naked_define
+#define __pdata
+#define __data
+#define __xdata
+#define __code const
+#define __reentrant
+#define __critical
+#define __interrupt(n)
+#define __at(n)
+
+#define ao_arch_reboot()	/* XXX */
+
+#define ao_arch_nop()		asm("nop")
+
+#define ao_arch_interrupt(n)	/* nothing */
+
+#undef putchar
+#undef getchar
+#define putchar(c)	ao_putchar(c)
+#define getchar		ao_getchar
+
+#define ao_arch_cpu_idle() do {			\
+		sleep_enable();			\
+		sei();				\
+		sleep_cpu();			\
+		sleep_disable();		\
+	} while (0)
+
+#define ao_arch_critical(b) do { cli(); do { b } while (0); sei(); } while (0)
+
+#define ao_mutex_get(m)
+#define ao_mutex_put(m)
+
+void
+ao_delay_until(uint16_t target);
+
+/* We can't hit 100 Hz, but we can hit 125 */
+#define AO_HERTZ	125
+
+void
+ao_eeprom_read(uint16_t addr, void *buf, uint16_t len);
+
+void
+ao_eeprom_write(uint16_t addr, void *buf, uint16_t len);
+
+#endif /* _AO_ARCH_H_ */
diff --git a/src/attiny/ao_arch_funcs.h b/src/attiny/ao_arch_funcs.h
new file mode 100644
index 00000000..8c9d1ae6
--- /dev/null
+++ b/src/attiny/ao_arch_funcs.h
@@ -0,0 +1,125 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+/*
+ * ao_spi.c
+ */
+
+#define ao_spi_get_mask(reg,mask,bus,speed) do {	\
+		(reg) &= ~(mask);		\
+	} while (0)
+
+#define ao_spi_put_mask(reg,mask,bus) do {	\
+		(reg) |= (mask);		\
+	} while (0)
+
+#define ao_spi_get_bit(reg,bit,pin,bus,speed) do {	\
+		(pin) = 0;			\
+	} while (0)
+
+#define ao_spi_put_bit(reg,bit,pin,bus) do {	\
+		(pin) = 1;			\
+	} while (0)
+
+
+#define ao_gpio_token_paster(x,y)		x ## y
+#define ao_gpio_token_evaluator(x,y)	ao_gpio_token_paster(x,y)
+
+#define ao_gpio_set(port, bit, pin, v) do {	\
+		if (v)				\
+			PORTB |= (1 << bit);	\
+		else				\
+			PORTB &= ~(1 << bit);	\
+	} while (0)
+
+/*
+ * The SPI mutex must be held to call either of these
+ * functions -- this mutex covers the entire SPI operation,
+ * from chip select low to chip select high
+ */
+
+#define ao_enable_output(port, bit, pin, v) do {			\
+		ao_gpio_set(port, bit, pin, v);				\
+		ao_gpio_token_evaluator(DDR,port) |= (1 << bit);	\
+	} while (0)
+
+
+void
+ao_spi_send_bus(void __xdata *block, uint16_t len) __reentrant;
+
+void
+ao_spi_recv_bus(void __xdata *block, uint16_t len) __reentrant;
+
+#define ao_spi_send(block, len, bus) ao_spi_send_bus(block, len)
+#define ao_spi_recv(block, len, bus) ao_spi_recv_bus(block, len)
+
+void
+ao_spi_init(void);
+
+#define ao_spi_get(bus, speed)
+#define ao_spi_put(bus)
+
+#define ao_spi_init_cs(port, mask) do {		\
+		PORTB |= (mask);		\
+		DDRB |= (mask);		\
+	} while (0)
+
+/* I2C */
+
+void
+ao_i2c_get(uint8_t i2c_index);
+
+uint8_t
+ao_i2c_start_bus(uint8_t address);
+
+#define ao_i2c_start(i,a)	ao_i2c_start_bus(a)
+
+void
+ao_i2c_put(uint8_t i2c_index);
+
+uint8_t
+ao_i2c_send_bus(void *block, uint16_t len, uint8_t stop);
+
+#define ao_i2c_send(b,l,i,s) ao_i2c_send_bus(b,l.s)
+
+uint8_t
+ao_i2c_send_fixed_bus(uint8_t value, uint16_t len, uint8_t stop);
+
+#define ao_i2c_send_fixed(v,l,i,s) ao_i2c_send_fixed_bus(v,l.s)
+
+uint8_t
+ao_i2c_recv_bus(void *block, uint16_t len, uint8_t stop);
+
+#define ao_i2c_recv(b,l,i,s) ao_i2c_recv_bus(b,l.s)
+
+void
+ao_i2c_init(void);
+
+/* notask.c */
+
+uint8_t
+ao_sleep(__xdata void *wchan);
+
+void
+ao_wakeup(__xdata void *wchan);
+
+extern alt_t	ao_max_height;
+
+extern void ao_report_altitude(void);
+
+void ao_delay_us(uint16_t us);
+
diff --git a/src/attiny/ao_clock.c b/src/attiny/ao_clock.c
new file mode 100644
index 00000000..a381b47f
--- /dev/null
+++ b/src/attiny/ao_clock.c
@@ -0,0 +1,114 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+
+volatile AO_TICK_TYPE	ao_tick_count;
+static volatile AO_TICK_TYPE	ao_wakeup_count;
+
+ISR(TIMER1_COMPA_vect)
+{
+	PORTB ^= 2;
+	++ao_tick_count;
+	if ((int16_t) (ao_tick_count - ao_wakeup_count) >= 0)
+		ao_wakeup((void *) &ao_tick_count);
+}
+
+uint16_t
+ao_time(void)
+{
+	uint16_t	r;
+
+	cli();
+	r = ao_tick_count;
+	sei();
+	return r;
+}
+
+void
+ao_timer_init(void)
+{
+	cli();
+	CLKPR = (1 << CLKPCE);
+	CLKPR = 0;
+	sei();
+
+	/* Overall division ratio is 512 * 125,
+	 * so our 8MHz base clock ends up as a 125Hz
+	 * clock
+	 */
+	TCCR1 = ((1 << CTC1) |		/* Clear timer on match */
+		 (0 << PWM1A) |		/* Not PWM mode */
+		 (0 << COM1A0) |	/* Don't change output pins */
+		 (0 << COM1A1) |	/*  ... */
+		 (1 << CS13) |		/* Prescale by 512 */
+		 (0 << CS12) |		/*  ... */
+		 (1 << CS11) |		/*  ... */
+		 (0 << CS10));		/*  ... */
+	GTCCR = ((0 << PWM1B) |		/* Not PWM mode */
+		 (0 << COM1B1) |	/* Don't change output pins */
+		 (0 << COM1B0) |	/*  ... */
+		 (0 << FOC1B) |		/* Don't force output compare */
+		 (0 << FOC1A) |		/*  ... */
+		 (0 << PSR1));		/* Don't bother to reset scaler */
+
+	OCR1A = 0;
+	OCR1B = 0;
+	OCR1C = 124;			/* Divide by as many 5s as we can (5^3 = 125) */
+
+	TIMSK = ((1 << OCIE1A) |	/* Enable TIMER1_COMPA interrupt */
+		 (0 << OCIE1B) |	/* Disable TIMER1_COMPB interrupt */
+		 (0 << TOIE1));		/* Disable TIMER1_OVF interrupt */
+	DDRB |= 2;
+}
+
+#define PER_LOOP	8
+#define US_LOOPS	((AVR_CLOCK / 1000000) / PER_LOOP)
+
+void ao_delay_us(uint16_t us)
+{
+#if US_LOOPS > 1
+	us *= US_LOOPS;
+#endif
+	for (;;) {
+		ao_arch_nop();
+		ao_arch_nop();
+		ao_arch_nop();
+		--us;
+		/* A bit funky to keep the optimizer
+		 * from short-circuiting the test */
+		if (!((uint8_t) (us | (us >> 8))))
+			break;
+	}
+}
+
+void
+ao_delay_until(uint16_t target)
+{
+	cli();
+	ao_wakeup_count = target;
+	while ((int16_t) (target - ao_tick_count) > 0)
+		ao_sleep((void *) &ao_tick_count);
+	sei();
+}
+
+void
+ao_delay(uint16_t ticks)
+{
+	ao_delay_until(ao_time() + ticks);
+}
+
diff --git a/src/attiny/ao_eeprom_tiny.c b/src/attiny/ao_eeprom_tiny.c
new file mode 100644
index 00000000..83014183
--- /dev/null
+++ b/src/attiny/ao_eeprom_tiny.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+
+static void
+ao_eeprom_wait(void)
+{
+	/* Wait for previous write to complete */
+	while (EECR & (1 << EEPE))
+		;
+}
+
+static uint8_t
+ao_eeprom_read_byte(uint16_t addr)
+{
+	uint8_t	v;
+
+	ao_eeprom_wait();
+	EEAR = addr;
+	cli();
+	EECR |= (1 << EERE);
+	v = EEDR;
+	sei();
+	return v;
+}
+
+static void
+ao_eeprom_write_byte(uint16_t addr, uint8_t v)
+{
+	ao_eeprom_wait();
+	EECR = (0 << EEPM1) | (0 << EEPM0);
+	EEAR = addr;
+	EEDR = v;
+	cli();
+	EECR |= (1 << EEMPE);
+	EECR |= (1 << EEPE);
+	sei();
+}
+
+void
+ao_eeprom_read(uint16_t addr, void *buf, uint16_t len)
+{
+	uint8_t	*b = buf;
+
+	while (len--)
+		*b++ = ao_eeprom_read_byte(addr++);
+}
+
+void
+ao_eeprom_write(uint16_t addr, void *buf, uint16_t len)
+{
+	uint8_t	*b = buf;
+
+	while (len--)
+		ao_eeprom_write_byte(addr++, *b++);
+}
diff --git a/src/attiny/ao_exti.c b/src/attiny/ao_exti.c
new file mode 100644
index 00000000..0ca10ca4
--- /dev/null
+++ b/src/attiny/ao_exti.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+#include <ao_exti.h>
+
+static void 	(*pcint_callback)(void);
+static uint8_t	pcint_mask;
+
+ISR(PCINT0_vect)
+{
+	if (PINB & pcint_mask)
+		(*pcint_callback)();
+}
+
+void
+ao_exti_setup_port(uint8_t pin, uint8_t mode, void (*callback)(void))
+{
+	pcint_callback = callback;
+	pcint_mask = (1 << pin);
+	ao_exti_disable(PORTB, pin);
+	GIMSK |= (1 << PCIE);
+}
diff --git a/src/attiny/ao_exti.h b/src/attiny/ao_exti.h
new file mode 100644
index 00000000..2ea4f47d
--- /dev/null
+++ b/src/attiny/ao_exti.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef _AO_EXTI_H_
+#define _AO_EXTI_H_
+
+void
+ao_exti_setup_port(uint8_t pin, uint8_t mode, void (*callback)(void));
+
+#define ao_exti_setup(port, pin, mode, callback)	ao_exti_setup_port(pin, mode, callback)
+
+#define ao_exti_enable(gpio, pin) 	(PCMSK |= (1 << (pin)))
+
+#define ao_exti_disable(gpio, pin)	(PCMSK &= ~(1 << (pin)))
+
+#define ao_exti_init()
+
+#define AO_EXTI_MODE_RISING	1
+
+#endif /* _AO_EXTI_H_ */
diff --git a/src/attiny/ao_i2c_attiny.c b/src/attiny/ao_i2c_attiny.c
new file mode 100644
index 00000000..2ee44fd2
--- /dev/null
+++ b/src/attiny/ao_i2c_attiny.c
@@ -0,0 +1,238 @@
+/*
+ * Copyright © 2011 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+
+/*
+ * ATtiny USI as an I2C interface
+ */
+
+#define I2C_USICR ((0 << USISIE) |	/* No start condition interrupt */ \
+		   (0 << USIOIE) |	/* No counter overflow interrupt */ \
+		   (1 << USIWM1) |	/* Two-wire mode */		\
+		   (0 << USIWM0) |	/*   ... */			\
+		   (1 << USICS1) |	/* Software clock strobe */	\
+		   (0 << USICS0) |	/*   ... */			\
+		   (1 << USICLK))	/*   ... */			\
+
+#define I2C_USICR_TICK (I2C_USICR | (1 << USITC))	/* Toggle the clock on every write */
+
+#define I2C_USISR_1BIT	((1<<USISIF)|	/* Clear start condition flag */ \
+			 (1<<USIOIF)|	/* Clear overflow flag */	\
+			 (1<<USIPF)|	/* Clear stop condition flag */	\
+			 (1<<USIDC)|	/* Clear data collision flag */	\
+			 (0xE<<USICNT0)) /* Set counter value to 0xe */
+
+#define I2C_USISR_8BIT	((1<<USISIF)|	/* Clear start condition flag */ \
+			 (1<<USIOIF)|	/* Clear overflow flag */	\
+			 (1<<USIPF)|	/* Clear stop condition flag */	\
+			 (1<<USIDC)|	/* Clear data collision flag */	\
+			 (0x0<<USICNT0)) /* Set counter value to 0 */
+
+#define T2_TWI    5 		/* >4.7μs */
+#define T4_TWI    4 		/* >4.0μs */
+
+static inline void ao_i2c_transfer(uint8_t sr)
+{
+	USISR = sr;
+	for (;;) {
+		ao_delay_us(T2_TWI);
+
+		/* Clock high */
+		USICR = I2C_USICR_TICK;
+
+		/* Wait for clock high (clock stretching) */
+		ao_delay_us(T4_TWI);
+		while(!(I2C_PIN & (1<<I2C_PIN_SCL)))
+			;
+
+		/* Clock low */
+		USICR = I2C_USICR_TICK;
+
+		/* Check for transfer complete */
+		if (USISR & (1 << USIOIF))
+			break;
+	}
+	ao_delay_us(T2_TWI);
+}
+
+static inline uint8_t ao_i2c_get_byte(uint8_t sr)
+{
+	uint8_t	ret;
+
+	/* Set SDA to input */
+	I2C_DIR &= ~(1<<I2C_PIN_SDA);
+
+	ao_i2c_transfer(sr);
+
+	ret = USIDR;
+	USIDR = 0xff;
+
+	/* Set SDA to output */
+	I2C_DIR |= (1<<I2C_PIN_SDA);
+
+	return ret;
+}
+
+static uint8_t
+ao_i2c_write_byte(uint8_t byte)
+{
+	/* Pull SCL low */
+	I2C_PORT &= ~(1<<I2C_PIN_SCL);
+
+	/* Write the byte */
+	USIDR = byte;
+      
+	/* Clock and verify (N)ACK from slave */
+
+	ao_i2c_transfer(I2C_USISR_8BIT);
+
+	if (ao_i2c_get_byte(I2C_USISR_1BIT) & 0x80)
+		return 0;
+
+	return 1;
+}
+
+static uint8_t
+ao_i2c_read_byte(uint8_t ack)
+{
+	uint8_t	ret;
+
+	/* Read the data */
+	ret = ao_i2c_get_byte(I2C_USISR_8BIT);
+
+	/* Ack it */
+	USIDR = ack;
+	ao_i2c_transfer(I2C_USISR_8BIT);
+
+	return ret;
+}
+
+uint8_t
+ao_i2c_start_bus(uint8_t address)
+{
+	/* Release SCL to ensure that (repeated) Start can be performed */
+
+	I2C_PORT |= (1<<I2C_PIN_SCL);
+
+	while( !(I2C_PORT & (1<<I2C_PIN_SCL)) )
+		;
+	ao_delay_us(T2_TWI);
+
+	/* Generate Start Condition */
+
+	/* Pull SDA low */
+	I2C_PORT &= ~(1<<I2C_PIN_SDA);
+	ao_delay_us(T4_TWI);                         
+
+	/* Pull SCL low */
+	I2C_PORT &= ~(1<<I2C_PIN_SCL);
+
+	/* Raise SDA */
+	I2C_PORT |= (1<<I2C_PIN_SDA);
+
+	return ao_i2c_write_byte(address);
+}
+
+static void
+ao_i2c_stop_bus(void)
+{
+	/* Pull SDA low. */
+	I2C_PORT &= ~(1<<I2C_PIN_SDA);
+
+	/* Release SCL. */
+	I2C_PORT |= (1<<I2C_PIN_SCL);
+
+	/* Wait for SCL to go high */
+	while( !(I2C_PIN & (1<<I2C_PIN_SCL)) );
+	ao_delay_us(T4_TWI);
+
+	/* Raise SDA */
+	I2C_PORT |= (1<<I2C_PIN_SDA);
+	ao_delay_us(T2_TWI);
+}
+
+/* Send bytes over SPI.
+ *
+ * This just polls; the SPI is set to go as fast as possible,
+ * so using interrupts would take way too long
+ */
+uint8_t
+ao_i2c_send_bus(void __xdata *block, uint16_t len, uint8_t stop)
+{
+	uint8_t	*d = block;
+
+	while (len--)
+		if (!ao_i2c_write_byte (*d++))
+			return 0;
+	if (stop)
+		ao_i2c_stop_bus();
+	return 1;
+}
+
+/* Send bytes over SPI.
+ *
+ * This just polls; the SPI is set to go as fast as possible,
+ * so using interrupts would take way too long
+ */
+uint8_t
+ao_i2c_send_fixed_bus(uint8_t d, uint16_t len, uint8_t stop)
+{
+	while (len--)
+		if (!ao_i2c_write_byte (d))
+			return 0;
+	if (stop)
+		ao_i2c_stop_bus();
+	return 1;
+}
+
+/* Receive bytes over SPI.
+ *
+ * Poll, sending zeros and reading data back
+ */
+uint8_t
+ao_i2c_recv_bus(void __xdata *block, uint16_t len, uint8_t stop)
+{
+	uint8_t	*d = block;
+
+	while (len--)
+		*d++ = ao_i2c_read_byte (len ? 0x00 : 0xff);
+	if (stop)
+		ao_i2c_stop_bus();
+	return 1;
+}
+
+/*
+ * Initialize USI
+ *
+ * Chip select is the responsibility of the caller
+ */
+
+void
+ao_i2c_init(void)
+{
+	/* Pull-ups on SDA and SCL */
+	I2C_PORT |= (1<<I2C_PIN_SDA);
+	I2C_PORT |= (1<<I2C_PIN_SCL);
+  
+	/* SCL and SDA are outputs */
+	I2C_DIR  |= (1<<I2C_PIN_SCL);
+	I2C_DIR  |= (1<<I2C_PIN_SDA);
+  
+	USIDR =  0xFF;
+	USICR =  I2C_USICR;
+}
diff --git a/src/attiny/ao_led.c b/src/attiny/ao_led.c
new file mode 100644
index 00000000..27bbea69
--- /dev/null
+++ b/src/attiny/ao_led.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright © 2009 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao.h"
+
+__pdata uint8_t ao_led_enable;
+
+#define LED_PORT	PORTB
+#define LED_DDR		DDRB
+
+void
+ao_led_on(uint8_t colors)
+{
+	LED_PORT |= (colors & ao_led_enable);
+}
+
+void
+ao_led_off(uint8_t colors)
+{
+	LED_PORT &= ~(colors & ao_led_enable);
+}
+
+void
+ao_led_set(uint8_t colors)
+{
+	LED_PORT = (LED_PORT & ~(ao_led_enable)) | (colors & ao_led_enable);
+}
+
+void
+ao_led_toggle(uint8_t colors)
+{
+	LED_PORT ^= (colors & ao_led_enable);
+}
+
+void
+ao_led_for(uint8_t colors, uint16_t ticks) __reentrant
+{
+	ao_led_on(colors);
+	ao_delay(ticks);
+	ao_led_off(colors);
+}
+
+void
+ao_led_init(uint8_t enable)
+{
+	ao_led_enable = enable;
+	LED_PORT &= ~enable;
+	LED_DDR |= enable;
+}
diff --git a/src/attiny/ao_spi_attiny.c b/src/attiny/ao_spi_attiny.c
new file mode 100644
index 00000000..064876d7
--- /dev/null
+++ b/src/attiny/ao_spi_attiny.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright © 2011 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+
+/*
+ * ATtiny USI as a SPI interface
+ */
+
+/*
+ * Transfer one byte in/out of the USI interface
+ */
+
+/* Three wire mode */
+#define SPI_USICR_WM	((0 << USIWM1) | (1 << USIWM0)) 
+#define SPI_USICR_CS	((1 << USICS1) | (0 << USICS0) | (1 << USICLK))
+
+#define SPI_USICR_FAST_2 ((1 << USIWM0) | (1 << USITC))
+#define SPI_USICR_FAST_1 ((1 << USIWM0) | (1 << USITC) | (1 << USICLK))
+
+
+static uint8_t
+ao_spi_transfer(uint8_t i)
+{
+	/* Load data register */
+	USIDR = i;
+
+#if 1
+	USISR = (1 << USIOIF);
+	do {
+		USICR = SPI_USICR_WM | SPI_USICR_CS | (1 << USITC);
+	} while ((USISR & (1 << USIOIF)) == 0);
+#else
+	/* 8 clocks */
+	USICR = SPI_USICR_FAST_1;
+	USICR = SPI_USICR_FAST_2;
+
+	USICR = SPI_USICR_FAST_1;
+	USICR = SPI_USICR_FAST_2;
+
+	USICR = SPI_USICR_FAST_1;
+	USICR = SPI_USICR_FAST_2;
+
+	USICR = SPI_USICR_FAST_1;
+	USICR = SPI_USICR_FAST_2;
+
+	USICR = SPI_USICR_FAST_1;
+	USICR = SPI_USICR_FAST_2;
+
+	USICR = SPI_USICR_FAST_1;
+	USICR = SPI_USICR_FAST_2;
+
+	USICR = SPI_USICR_FAST_1;
+	USICR = SPI_USICR_FAST_2;
+
+	USICR = SPI_USICR_FAST_1;
+	USICR = SPI_USICR_FAST_2;
+#endif
+
+	/* Pull data from the port */
+	return USIDR;
+}
+
+/* Send bytes over SPI.
+ *
+ * This just polls; the SPI is set to go as fast as possible,
+ * so using interrupts would take way too long
+ */
+void
+ao_spi_send_bus(void __xdata *block, uint16_t len) __reentrant
+{
+	uint8_t	*d = block;
+
+	while (len--)
+		ao_spi_transfer (*d++);
+}
+
+/* Receive bytes over SPI.
+ *
+ * Poll, sending zeros and reading data back
+ */
+void
+ao_spi_recv_bus(void __xdata *block, uint16_t len) __reentrant
+{
+	uint8_t	*d = block;
+
+	while (len--)
+		*d++ = ao_spi_transfer (0xff);
+}
+
+/*
+ * Initialize USI
+ *
+ * Chip select is the responsibility of the caller
+ */
+
+void
+ao_spi_init(void)
+{
+#if 1
+	USICR = (1 << USIWM0) | (1 << USICS1) | (1 << USICLK);
+#else
+	USICR = SPI_USICR_FAST_2;
+#endif
+	SPI_DIR &= ~(1 << DDB0);	/* DI */
+	SPI_DIR |= (1 << DDB1);		/* DO */
+	SPI_DIR |= (1 << DDB2);		/* SCLK */
+	SPI_DIR |= (1 << DDB3);		/* CS */
+}