stm32f0: Initial support for i2c on stm32f0

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2019-11-13 22:20:29 -05:00
parent d39142139e
commit 9ff4f1bb2f
4 changed files with 100 additions and 6 deletions

View File

@ -7,7 +7,7 @@ config STM32_SELECT
default y default y
select HAVE_GPIO select HAVE_GPIO
select HAVE_GPIO_ADC select HAVE_GPIO_ADC
select HAVE_GPIO_I2C if !MACH_STM32F0 select HAVE_GPIO_I2C
select HAVE_GPIO_SPI select HAVE_GPIO_SPI
select HAVE_GPIO_BITBANGING select HAVE_GPIO_BITBANGING

View File

@ -27,13 +27,13 @@ src-y += generic/armcm_boot.c generic/armcm_irq.c generic/armcm_reset.c
src-$(CONFIG_MACH_STM32F0) += ../lib/stm32f0/system_stm32f0xx.c src-$(CONFIG_MACH_STM32F0) += ../lib/stm32f0/system_stm32f0xx.c
src-$(CONFIG_MACH_STM32F0) += generic/timer_irq.c stm32/stm32f0_timer.c src-$(CONFIG_MACH_STM32F0) += generic/timer_irq.c stm32/stm32f0_timer.c
src-$(CONFIG_MACH_STM32F0) += stm32/stm32f0.c stm32/stm32f0_adc.c src-$(CONFIG_MACH_STM32F0) += stm32/stm32f0.c stm32/stm32f0_adc.c
src-$(CONFIG_MACH_STM32F0) += stm32/stm32f0_i2c.c
src-$(CONFIG_MACH_STM32F1) += ../lib/stm32f1/system_stm32f1xx.c src-$(CONFIG_MACH_STM32F1) += ../lib/stm32f1/system_stm32f1xx.c
src-$(CONFIG_MACH_STM32F1) += stm32/stm32f1.c generic/armcm_timer.c src-$(CONFIG_MACH_STM32F1) += stm32/stm32f1.c generic/armcm_timer.c
src-$(CONFIG_MACH_STM32F1) += stm32/adc.c src-$(CONFIG_MACH_STM32F1) += stm32/adc.c stm32/i2c.c
src-$(CONFIG_MACH_STM32F4) += ../lib/stm32f4/system_stm32f4xx.c src-$(CONFIG_MACH_STM32F4) += ../lib/stm32f4/system_stm32f4xx.c
src-$(CONFIG_MACH_STM32F4) += stm32/stm32f4.c generic/armcm_timer.c src-$(CONFIG_MACH_STM32F4) += stm32/stm32f4.c generic/armcm_timer.c
src-$(CONFIG_MACH_STM32F4) += stm32/adc.c src-$(CONFIG_MACH_STM32F4) += stm32/adc.c stm32/i2c.c
src-$(CONFIG_HAVE_GPIO_I2C) += stm32/i2c.c
src-$(CONFIG_HAVE_GPIO_SPI) += stm32/spi.c src-$(CONFIG_HAVE_GPIO_SPI) += stm32/spi.c
usb-src-$(CONFIG_HAVE_STM32_USBFS) := stm32/usbfs.c usb-src-$(CONFIG_HAVE_STM32_USBFS) := stm32/usbfs.c
usb-src-$(CONFIG_HAVE_STM32_USBOTG) := stm32/usbotg.c usb-src-$(CONFIG_HAVE_STM32_USBOTG) := stm32/usbotg.c

View File

@ -128,9 +128,12 @@ pll_setup(void)
while ((RCC->CFGR & RCC_CFGR_SWS_Msk) != RCC_CFGR_SWS_PLL) while ((RCC->CFGR & RCC_CFGR_SWS_Msk) != RCC_CFGR_SWS_PLL)
; ;
// Select PLL as source for USB clock // Setup CFGR3 register
uint32_t cfgr3 = RCC_CFGR3_I2C1SW;
if (CONFIG_USBSERIAL) if (CONFIG_USBSERIAL)
RCC->CFGR3 = RCC_CFGR3_USBSW; // Select PLL as source for USB clock
cfgr3 |= RCC_CFGR3_USBSW;
RCC->CFGR3 = cfgr3;
} }
// Configure and enable internal 48Mhz clock on the stm32f042 // Configure and enable internal 48Mhz clock on the stm32f042
@ -153,6 +156,9 @@ hsi48_setup(void)
enable_pclock(CRS_BASE); enable_pclock(CRS_BASE);
CRS->CR |= CRS_CR_AUTOTRIMEN | CRS_CR_CEN; CRS->CR |= CRS_CR_AUTOTRIMEN | CRS_CR_CEN;
} }
// Setup I2C1 clock
RCC->CFGR3 = RCC_CFGR3_I2C1SW;
#endif #endif
} }

88
src/stm32/stm32f0_i2c.c Normal file
View File

@ -0,0 +1,88 @@
// I2C functions on stm32f0
//
// Copyright (C) 2019 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU GPLv3 license.
#include "board/misc.h" // timer_is_before
#include "command.h" // shutdown
#include "gpio.h" // i2c_setup
#include "internal.h" // GPIO
#include "sched.h" // sched_shutdown
struct i2c_info {
I2C_TypeDef *i2c;
uint8_t scl_pin, sda_pin, function;
};
DECL_ENUMERATION("i2c_bus", "i2c1", 0);
DECL_CONSTANT_STR("BUS_PINS_i2c1", "PB6,PB7");
DECL_ENUMERATION("i2c_bus", "i2c1a", 1);
DECL_CONSTANT_STR("BUS_PINS_i2c1a", "PF1,PF0");
static const struct i2c_info i2c_bus[] = {
{ I2C1, GPIO('B', 6), GPIO('B', 7), GPIO_FUNCTION(1) },
{ I2C1, GPIO('F', 1), GPIO('F', 0), GPIO_FUNCTION(1) },
};
struct i2c_config
i2c_setup(uint32_t bus, uint32_t rate, uint8_t addr)
{
// Lookup requested i2c bus
if (bus >= ARRAY_SIZE(i2c_bus))
shutdown("Unsupported i2c bus");
const struct i2c_info *ii = &i2c_bus[bus];
I2C_TypeDef *i2c = ii->i2c;
if (!is_enabled_pclock((uint32_t)i2c)) {
// Enable i2c clock and gpio
enable_pclock((uint32_t)i2c);
gpio_peripheral(ii->scl_pin, ii->function | GPIO_OPEN_DRAIN, 1);
gpio_peripheral(ii->sda_pin, ii->function | GPIO_OPEN_DRAIN, 1);
// Set 100Khz frequency and enable
i2c->TIMINGR = ((0xB << I2C_TIMINGR_PRESC_Pos)
| (0x13 << I2C_TIMINGR_SCLL_Pos)
| (0xF << I2C_TIMINGR_SCLH_Pos)
| (0x2 << I2C_TIMINGR_SDADEL_Pos)
| (0x4 << I2C_TIMINGR_SCLDEL_Pos));
i2c->CR1 = I2C_CR1_PE;
}
return (struct i2c_config){ .i2c=i2c, .addr=addr<<1 };
}
static uint32_t
i2c_wait(I2C_TypeDef *i2c, uint32_t set, uint32_t timeout)
{
for (;;) {
uint32_t isr = i2c->ISR;
if (isr & set)
return isr;
if (!timer_is_before(timer_read_time(), timeout))
shutdown("i2c timeout");
}
}
void
i2c_write(struct i2c_config config, uint8_t write_len, uint8_t *write)
{
I2C_TypeDef *i2c = config.i2c;
uint32_t timeout = timer_read_time() + timer_from_us(5000);
// Send start and address
i2c->CR2 = (I2C_CR2_START | config.addr | (write_len << I2C_CR2_NBYTES_Pos)
| I2C_CR2_AUTOEND);
while (write_len--) {
i2c_wait(i2c, I2C_ISR_TXIS, timeout);
i2c->TXDR = *write++;
}
i2c_wait(i2c, I2C_ISR_TXE, timeout);
}
void
i2c_read(struct i2c_config config, uint8_t reg_len, uint8_t *reg
, uint8_t read_len, uint8_t *read)
{
shutdown("i2c_read not supported on stm32");
}