diff options
Diffstat (limited to 'src/sam3x8e/gpio.c')
| -rw-r--r-- | src/sam3x8e/gpio.c | 85 |
1 files changed, 1 insertions, 84 deletions
diff --git a/src/sam3x8e/gpio.c b/src/sam3x8e/gpio.c index b12dc447..f48c5f0d 100644 --- a/src/sam3x8e/gpio.c +++ b/src/sam3x8e/gpio.c @@ -1,11 +1,9 @@ // GPIO functions on sam3x8e // -// Copyright (C) 2016,2017 Kevin O'Connor <kevin@koconnor.net> +// Copyright (C) 2016-2018 Kevin O'Connor <kevin@koconnor.net> // // This file may be distributed under the terms of the GNU GPLv3 license. -#include <stdint.h> // uint32_t -#include "autoconf.h" // CONFIG_CLOCK_FREQ #include "board/irq.h" // irq_save #include "command.h" // shutdown #include "compiler.h" // ARRAY_SIZE @@ -133,84 +131,3 @@ gpio_in_read(struct gpio_in g) Pio *regs = g.regs; return !!(regs->PIO_PDSR & g.bit); } - - -/**************************************************************** - * Analog to Digital Converter (ADC) pins - ****************************************************************/ - -static const uint8_t adc_pins[] = { - GPIO('A', 2), GPIO('A', 3), GPIO('A', 4), GPIO('A', 6), - GPIO('A', 22), GPIO('A', 23), GPIO('A', 24), GPIO('A', 16), - GPIO('B', 12), GPIO('B', 13), GPIO('B', 17), GPIO('B', 18), - GPIO('B', 19), GPIO('B', 20) -}; - -#define ADC_FREQ_MAX 20000000 -DECL_CONSTANT(ADC_MAX, 4095); - -struct gpio_adc -gpio_adc_setup(uint8_t pin) -{ - // Find pin in adc_pins table - int chan; - for (chan=0; ; chan++) { - if (chan >= ARRAY_SIZE(adc_pins)) - shutdown("Not a valid ADC pin"); - if (adc_pins[chan] == pin) - break; - } - - if (!(PMC->PMC_PCSR1 & (1 << (ID_ADC-32)))) { - // Setup ADC - PMC->PMC_PCER1 = 1 << (ID_ADC-32); - uint32_t prescal = SystemCoreClock / (2 * ADC_FREQ_MAX) - 1; - ADC->ADC_MR = (ADC_MR_PRESCAL(prescal) - | ADC_MR_STARTUP_SUT768 - | ADC_MR_TRANSFER(1)); - } - return (struct gpio_adc){ .bit = 1 << chan }; -} - -// Try to sample a value. Returns zero if sample ready, otherwise -// returns the number of clock ticks the caller should wait before -// retrying this function. -uint32_t -gpio_adc_sample(struct gpio_adc g) -{ - uint32_t chsr = ADC->ADC_CHSR & 0xffff; - if (!chsr) { - // Start sample - ADC->ADC_CHER = g.bit; - ADC->ADC_CR = ADC_CR_START; - goto need_delay; - } - if (chsr != g.bit) - // Sampling in progress on another channel - goto need_delay; - if (!(ADC->ADC_ISR & ADC_ISR_DRDY)) - // Conversion still in progress - goto need_delay; - // Conversion ready - return 0; -need_delay: - return ADC_FREQ_MAX * 1000ULL / CONFIG_CLOCK_FREQ; -} - -// Read a value; use only after gpio_adc_sample() returns zero -uint16_t -gpio_adc_read(struct gpio_adc g) -{ - ADC->ADC_CHDR = g.bit; - return ADC->ADC_LCDR; -} - -// Cancel a sample that may have been started with gpio_adc_sample() -void -gpio_adc_cancel_sample(struct gpio_adc g) -{ - irqstatus_t flag = irq_save(); - if ((ADC->ADC_CHSR & 0xffff) == g.bit) - gpio_adc_read(g); - irq_restore(flag); -} |