diff options
Diffstat (limited to 'src/stm32f1/gpio.c')
| -rw-r--r-- | src/stm32f1/gpio.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/stm32f1/gpio.c b/src/stm32f1/gpio.c new file mode 100644 index 00000000..74bb72af --- /dev/null +++ b/src/stm32f1/gpio.c @@ -0,0 +1,213 @@ +// GPIO functions on STM32F1 +// +// Copyright (C) 2018 Grigori Goronzy <greg@kinoho.net> +// +// This file may be distributed under the terms of the GNU GPLv3 license. + +#include <stdint.h> // uint32_t +#include <stdbool.h> +#include "autoconf.h" // CONFIG_CLOCK_FREQ +#include "command.h" // shutdown +#include "compiler.h" // ARRAY_SIZE +#include "gpio.h" // gpio_out_setup +#include "stm32f1xx.h" +#include "stm32f1xx_ll_gpio.h" +#include "stm32f1xx_ll_adc.h" +#include "sched.h" // sched_shutdown +#include "board/irq.h" +#include "board/io.h" + + +/**************************************************************** + * Pin mappings + ****************************************************************/ + +#define GPIO(PORT, NUM) (((PORT)-'A') * 16 + (NUM)) +#define GPIO2PORT(PIN) ((PIN) / 16) + +static GPIO_TypeDef *const digital_regs[] = { + GPIOA, GPIOB, GPIOC, GPIOD, GPIOE +}; + +static uint32_t const digital_pins[] = { + LL_GPIO_PIN_0, + LL_GPIO_PIN_1, + LL_GPIO_PIN_2, + LL_GPIO_PIN_3, + LL_GPIO_PIN_4, + LL_GPIO_PIN_5, + LL_GPIO_PIN_6, + LL_GPIO_PIN_7, + LL_GPIO_PIN_8, + LL_GPIO_PIN_9, + LL_GPIO_PIN_10, + LL_GPIO_PIN_11, + LL_GPIO_PIN_12, + LL_GPIO_PIN_13, + LL_GPIO_PIN_14, + LL_GPIO_PIN_15, +}; + +/**************************************************************** + * General Purpose Input Output (GPIO) pins + ****************************************************************/ + +struct gpio_out +gpio_out_setup(uint8_t pin, uint8_t val) +{ + if (GPIO2PORT(pin) >= ARRAY_SIZE(digital_regs)) + goto fail; + GPIO_TypeDef *regs = digital_regs[GPIO2PORT(pin)]; + uint32_t bit = digital_pins[pin % 16]; + irqstatus_t flag = irq_save(); + if (val) + LL_GPIO_SetOutputPin(regs, bit); + else + LL_GPIO_ResetOutputPin(regs, bit); + LL_GPIO_SetPinMode(regs, bit, LL_GPIO_MODE_OUTPUT); + irq_restore(flag); + return (struct gpio_out){ .regs = regs, .bit = bit }; +fail: + shutdown("Not an output pin"); +} + +void +gpio_out_toggle(struct gpio_out g) +{ + LL_GPIO_TogglePin(g.regs, g.bit); +} + +void +gpio_out_write(struct gpio_out g, uint8_t val) +{ + if (val) + LL_GPIO_SetOutputPin(g.regs, g.bit); + else + LL_GPIO_ResetOutputPin(g.regs, g.bit); +} + + +struct gpio_in +gpio_in_setup(uint8_t pin, int8_t pull_up) +{ + if (GPIO2PORT(pin) >= ARRAY_SIZE(digital_regs)) + goto fail; + GPIO_TypeDef *regs = digital_regs[GPIO2PORT(pin)]; + uint32_t bit = digital_pins[pin % 16]; + irqstatus_t flag = irq_save(); + if (pull_up) { + LL_GPIO_SetPinMode(regs, bit, LL_GPIO_MODE_INPUT); + LL_GPIO_SetPinPull(regs, bit, LL_GPIO_PULL_UP); + } else { + LL_GPIO_SetPinMode(regs, bit, LL_GPIO_MODE_FLOATING); + } + irq_restore(flag); + return (struct gpio_in){ .regs = regs, .bit = bit }; +fail: + shutdown("Not an input pin"); +} + +uint8_t +gpio_in_read(struct gpio_in g) +{ + return LL_GPIO_IsInputPinSet(g.regs, g.bit); +} + + +/**************************************************************** + * Analog to Digital Converter (ADC) pins + ****************************************************************/ + +DECL_CONSTANT(ADC_MAX, 4095); + +#define ADC_DELAY (240 * 8) + +static bool adc_busy; +static uint32_t adc_current_channel; + +static const uint8_t adc_pins[] = { + GPIO('A', 0), GPIO('A', 1), GPIO('A', 2), GPIO('A', 3), + GPIO('A', 4), GPIO('A', 5), GPIO('A', 6), GPIO('A', 7), + GPIO('B', 0), GPIO('B', 1), GPIO('C', 0), GPIO('C', 1), + GPIO('C', 2), GPIO('C', 3) +}; + +static const uint32_t adc_channels[] = { + LL_ADC_CHANNEL_0, + LL_ADC_CHANNEL_1, + LL_ADC_CHANNEL_2, + LL_ADC_CHANNEL_3, + LL_ADC_CHANNEL_4, + LL_ADC_CHANNEL_5, + LL_ADC_CHANNEL_6, + LL_ADC_CHANNEL_7, + LL_ADC_CHANNEL_8, + LL_ADC_CHANNEL_9, + LL_ADC_CHANNEL_10, + LL_ADC_CHANNEL_11, + LL_ADC_CHANNEL_12, + LL_ADC_CHANNEL_13, + LL_ADC_CHANNEL_14, + LL_ADC_CHANNEL_15, +}; + +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; + } + + GPIO_TypeDef *regs = digital_regs[GPIO2PORT(pin)]; + uint32_t bit = digital_pins[pin % 16]; + LL_GPIO_SetPinMode(regs, bit, LL_GPIO_MODE_ANALOG); + + return (struct gpio_adc){ .bit = adc_channels[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) +{ + /* ADC not busy, start conversion */ + if (!readb(&adc_busy)) { + LL_ADC_REG_SetSequencerRanks(ADC1, LL_ADC_REG_RANK_1, g.bit); + LL_ADC_SetChannelSamplingTime(ADC1, g.bit, LL_ADC_SAMPLINGTIME_239CYCLES_5); + LL_ADC_REG_StartConversionSWStart(ADC1); + adc_busy = true; + adc_current_channel = g.bit; + return ADC_DELAY; + /* ADC finished conversion for this channel */ + } else if (LL_ADC_IsActiveFlag_EOS(ADC1) && + readl(&adc_current_channel) == g.bit) { + LL_ADC_ClearFlag_EOS(ADC1); + adc_busy = false; + return 0; + } + /* Wants to sample another channel, or not finished yet */ + return ADC_DELAY; +} + +// Read a value; use only after gpio_adc_sample() returns zero +uint16_t +gpio_adc_read(struct gpio_adc g) +{ + return LL_ADC_REG_ReadConversionData12(ADC1); +} + +// Cancel a sample that may have been started with gpio_adc_sample() +void +gpio_adc_cancel_sample(struct gpio_adc g) +{ + if (readb(&adc_busy) && readl(&adc_current_channel) == g.bit) { + adc_busy = false; + LL_ADC_ClearFlag_EOS(ADC1); + } +} |