diff options
| author | Kevin O'Connor <kevin@koconnor.net> | 2017-04-11 09:56:08 -0400 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2017-04-11 10:01:22 -0400 |
| commit | 7a7b98cc31dff8cb7f1a6a1ab886362a0802be66 (patch) | |
| tree | 00cf5308e651d7f4b980408b3a0cc147376f04dc /src | |
| parent | 15d5837322db5298f29d0d2ba92416fd5a40cc8c (diff) | |
| download | kutter-7a7b98cc31dff8cb7f1a6a1ab886362a0802be66.tar.gz kutter-7a7b98cc31dff8cb7f1a6a1ab886362a0802be66.tar.xz kutter-7a7b98cc31dff8cb7f1a6a1ab886362a0802be66.zip | |
sam3x8e: Rework adc pin search to be more clear
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Diffstat (limited to 'src')
| -rw-r--r-- | src/sam3x8e/gpio.c | 38 |
1 files changed, 22 insertions, 16 deletions
diff --git a/src/sam3x8e/gpio.c b/src/sam3x8e/gpio.c index f2e10069..d20f3f77 100644 --- a/src/sam3x8e/gpio.c +++ b/src/sam3x8e/gpio.c @@ -1,6 +1,6 @@ // GPIO functions on sam3x8e // -// Copyright (C) 2016 Kevin O'Connor <kevin@koconnor.net> +// Copyright (C) 2016,2017 Kevin O'Connor <kevin@koconnor.net> // // This file may be distributed under the terms of the GNU GPLv3 license. @@ -28,7 +28,7 @@ static Pio * const digital_regs[] = { /**************************************************************** - * gpio functions + * General Purpose Input Output (GPIO) pins ****************************************************************/ void @@ -116,6 +116,10 @@ gpio_in_read(struct gpio_in g) } +/**************************************************************** + * 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), @@ -129,22 +133,24 @@ DECL_CONSTANT(ADC_MAX, 4096); struct gpio_adc gpio_adc_setup(uint8_t pin) { + // Find pin in adc_pins table int chan; - for (chan=0; chan<ARRAY_SIZE(adc_pins); chan++) { - if (adc_pins[chan] != pin) - continue; - // Found PIN - 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 }; + 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)); } - shutdown("Not a valid ADC pin"); + return (struct gpio_adc){ .bit = 1 << chan }; } // Try to sample a value. Returns zero if sample ready, otherwise |