diff options
Diffstat (limited to 'src/stm32/n32g45x_adc.c')
| -rw-r--r-- | src/stm32/n32g45x_adc.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/src/stm32/n32g45x_adc.c b/src/stm32/n32g45x_adc.c new file mode 100644 index 00000000..d27e70c9 --- /dev/null +++ b/src/stm32/n32g45x_adc.c @@ -0,0 +1,185 @@ +// ADC functions on N32G45x +// +// Copyright (C) 2022-2023 Alexey Golyshin <stas2z@gmail.com> +// +// This file may be distributed under the terms of the GNU GPLv3 license. + +#include "board/irq.h" // irq_save +#include "board/misc.h" // timer_from_us +#include "command.h" // shutdown +#include "compiler.h" // ARRAY_SIZE +#include "generic/armcm_timer.h" // udelay +#include "gpio.h" // gpio_adc_setup +#include "internal.h" // GPIO +#include "sched.h" // sched_shutdown +#include "n32g45x_adc.h" // ADC + +DECL_CONSTANT("ADC_MAX", 4095); + +#define ADC_TEMPERATURE_PIN 0xfe +DECL_ENUMERATION("pin", "ADC_TEMPERATURE", ADC_TEMPERATURE_PIN); + +static const uint8_t adc_pins[] = { + // ADC1 + 0, GPIO('A', 0), GPIO('A', 1), GPIO('A', 6), + GPIO('A', 3), GPIO('F', 4), 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, + ADC_TEMPERATURE_PIN, 0, 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, + // ADC2 + 0, GPIO('A', 4), GPIO('A', 5), GPIO('B', 1), + GPIO('A', 7), GPIO('C', 4), GPIO('C', 0), GPIO('C', 1), + GPIO('C', 2), GPIO('C', 3), GPIO('F', 2), GPIO('A', 2), + GPIO('C', 5), GPIO('B', 2), 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, +#if CONFIG_MACH_N32G455 // ADC3/4 for G455 only + // ADC3 + 0, GPIO('B', 11), GPIO('E', 9), GPIO('E', 13), + GPIO('E', 12), GPIO('B', 13), GPIO('E', 8), GPIO('D', 10), + GPIO('D', 11), GPIO('D', 12), GPIO('D', 13), GPIO('D', 14), + GPIO('B', 0), GPIO('E', 7), GPIO('E', 10), GPIO('E', 11), + 0, 0, 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, + // ADC4 + 0, GPIO('E', 14), GPIO('E', 15), GPIO('B', 12), + GPIO('B', 14), GPIO('B', 15), 0, 0, + 0, 0, 0, 0, + GPIO('D', 8), GPIO('D', 9), 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, +#endif +}; + +// Perform calibration +static void +adc_calibrate(ADC_Module *adc) +{ + adc->CTRL2 = CTRL2_AD_ON_SET; + while (!(adc->CTRL3 & ADC_FLAG_RDY)) + ; + adc->CTRL3 &= (~ADC_CTRL3_BPCAL_MSK); + udelay(10); + adc->CTRL2 = CTRL2_AD_ON_SET | CTRL2_CAL_SET; + while (adc->CTRL2 & CTRL2_CAL_SET) + ; +} + +struct gpio_adc +gpio_adc_setup(uint32_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; + } + + // Determine which ADC block to use + ADC_Module *adc; + if ((chan >> 5) == 0) + adc = NS_ADC1; + if ((chan >> 5) == 1) + adc = NS_ADC2; + if ((chan >> 5) == 2) + adc = NS_ADC3; + if ((chan >> 5) == 3) + adc = NS_ADC4; + chan &= 0x1F; + + // Enable the ADC + uint32_t reg_temp; + reg_temp = ADC_RCC_AHBPCLKEN; + reg_temp |= (RCC_AHB_PERIPH_ADC1 | RCC_AHB_PERIPH_ADC2 | + RCC_AHB_PERIPH_ADC3 | RCC_AHB_PERIPH_ADC4); + ADC_RCC_AHBPCLKEN = reg_temp; + + reg_temp = ADC_RCC_CFG2; + reg_temp &= CFG2_ADCPLLPRES_RESET_MASK; + reg_temp |= RCC_ADCPLLCLK_DIV1; + reg_temp &= RCC_ADCPLLCLK_DISABLE; + ADC_RCC_CFG2 = reg_temp; + + reg_temp = ADC_RCC_CFG2; + reg_temp &= CFG2_ADCHPRES_RESET_MASK; + reg_temp |= RCC_ADCHCLK_DIV16; + ADC_RCC_CFG2 = reg_temp; + + ADC_InitType ADC_InitStructure; + ADC_InitStructure.WorkMode = ADC_WORKMODE_INDEPENDENT; + ADC_InitStructure.MultiChEn = 0; + ADC_InitStructure.ContinueConvEn = 0; + ADC_InitStructure.ExtTrigSelect = ADC_EXT_TRIGCONV_NONE; + ADC_InitStructure.DatAlign = ADC_DAT_ALIGN_R; + ADC_InitStructure.ChsNumber = 1; + ADC_Init(adc, &ADC_InitStructure); + + adc_calibrate(adc); + + if (pin == ADC_TEMPERATURE_PIN) { + NS_ADC1->CTRL2 |= CTRL2_TSVREFE_SET; + VREF1P2_CTRL |= (1<<10); + } else { + gpio_peripheral(pin, GPIO_ANALOG, 0); + } + + return (struct gpio_adc){ .adc = adc, .chan = 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_Module *adc = g.adc; + uint32_t sr = adc->STS; + if (sr & ADC_STS_STR) { + if (!(sr & ADC_STS_ENDC) || adc->RSEQ3 != g.chan) + // Conversion still in progress or busy on another channel + goto need_delay; + // Conversion ready + return 0; + } + // ADC timing: clock=4Mhz, Tconv=12.5, Tsamp=41.5, total=13.500us + ADC_ConfigRegularChannel(adc, g.chan, 1, ADC_SAMP_TIME_41CYCLES5); + adc->CTRL2 |= CTRL2_AD_ON_SET; + adc->CTRL2 |= CTRL2_EXT_TRIG_SWSTART_SET; + +need_delay: + return timer_from_us(20); +} + +// Read a value; use only after gpio_adc_sample() returns zero +uint16_t +gpio_adc_read(struct gpio_adc g) +{ + ADC_Module *adc = g.adc; + adc->STS &= ~ADC_STS_ENDC; + adc->STS &= ~ADC_STS_STR; + adc->CTRL2 &= CTRL2_EXT_TRIG_SWSTART_RESET; + uint16_t result = adc->DAT; + return result; +} + +// Cancel a sample that may have been started with gpio_adc_sample() +void +gpio_adc_cancel_sample(struct gpio_adc g) +{ + ADC_Module *adc = g.adc; + irqstatus_t flag = irq_save(); + if (adc->STS & ADC_STS_STR) + gpio_adc_read(g); + irq_restore(flag); +} |