diff options
Diffstat (limited to 'src/avr/gpio.c')
| -rw-r--r-- | src/avr/gpio.c | 96 |
1 files changed, 85 insertions, 11 deletions
diff --git a/src/avr/gpio.c b/src/avr/gpio.c index d4b784f5..0ae7e52f 100644 --- a/src/avr/gpio.c +++ b/src/avr/gpio.c @@ -352,29 +352,103 @@ gpio_adc_cancel_sample(struct gpio_adc g) ****************************************************************/ #if CONFIG_MACH_atmega168 || CONFIG_MACH_atmega328 -static const uint8_t SS = GPIO('B', 2), SCK = GPIO('B', 5), MOSI = GPIO('B', 3); +static const uint8_t SS = GPIO('B', 2), SCK = GPIO('B', 5); +static const uint8_t MOSI = GPIO('B', 3), MISO = GPIO('B', 4); #elif CONFIG_MACH_atmega644p || CONFIG_MACH_atmega1284p -static const uint8_t SS = GPIO('B', 4), SCK = GPIO('B', 7), MOSI = GPIO('B', 5); +static const uint8_t SS = GPIO('B', 4), SCK = GPIO('B', 7); +static const uint8_t MOSI = GPIO('B', 5), MISO = GPIO('B', 6); #elif CONFIG_MACH_at90usb1286 || CONFIG_MACH_at90usb646 || CONFIG_MACH_atmega1280 || CONFIG_MACH_atmega2560 -static const uint8_t SS = GPIO('B', 0), SCK = GPIO('B', 1), MOSI = GPIO('B', 2); +static const uint8_t SS = GPIO('B', 0), SCK = GPIO('B', 1); +static const uint8_t MOSI = GPIO('B', 2), MISO = GPIO('B', 3); #endif -void -spi_config(void) +static void +spi_init(void) { gpio_out_setup(SS, 1); gpio_out_setup(SCK, 0); gpio_out_setup(MOSI, 0); + gpio_in_setup(MISO, 0); + SPCR = (1<<MSTR) | (1<<SPE); + SPSR = 0; +} + +struct spi_config +spi_setup(uint32_t bus, uint8_t mode, uint32_t rate) +{ + if (bus || mode > 3) + shutdown("Invalid spi_setup parameters"); + + // Make sure the SPI interface is enabled + spi_init(); + + // Setup rate + struct spi_config config = {0, 0}; + if (rate >= (CONFIG_CLOCK_FREQ / 2)) { + config.spsr = (1<<SPI2X); + } else if (rate >= (CONFIG_CLOCK_FREQ / 4)) { + config.spcr = 0; + } else if (rate >= (CONFIG_CLOCK_FREQ / 8)) { + config.spcr = 1; + config.spsr = (1<<SPI2X); + } else if (rate >= (CONFIG_CLOCK_FREQ / 16)) { + config.spcr = 1; + } else if (rate >= (CONFIG_CLOCK_FREQ / 32)) { + config.spcr = 2; + config.spsr = (1<<SPI2X); + } else if (rate >= (CONFIG_CLOCK_FREQ / 64)) { + config.spcr = 2; + } else { + config.spcr = 3; + } + + // Setup mode + config.spcr |= (1<<SPE) | (1<<MSTR); + switch(mode) { + case 0: { + // MODE 0 - CPOL=0, CPHA=0 + break; + } + case 1: { + // MODE 1 - CPOL=0, CPHA=1 + config.spcr |= (1<<CPHA); + break; + } + case 2: { + // MODE 2 - CPOL=1, CPHA=0 + config.spcr |= (1<<CPOL); + break; + } + case 3: { + // MODE 3 - CPOL=1, CPHA=1 + config.spcr |= (1<<CPOL) | (1<<CPHA); + break; + } + } + + return config; } void -spi_transfer(char *data, uint8_t len) +spi_transfer(struct spi_config config, uint8_t receive_data + , uint8_t len, uint8_t *data) { - while (len--) { - SPDR = *data; - while (!(SPSR & (1<<SPIF))) - ; - *data++ = SPDR; + SPCR = config.spcr; + SPSR = config.spsr; + + if (receive_data) { + while (len--) { + SPDR = *data; + while (!(SPSR & (1<<SPIF))) + ; + *data++ = SPDR; + } + } else { + while (len--) { + SPDR = *data++; + while (!(SPSR & (1<<SPIF))) + ; + } } } |