cpu/rpx0xx: Add PIO I2C implementation

RIOT-OS · Dec 19, 2021 · 442db5d · 442db5d
1 parent 83af45e
commit 442db5d
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diff --git a/boards/rpi-pico/Kconfig b/boards/rpi-pico/Kconfig
@@ -12,6 +12,7 @@ config BOARD_RPI_PICO
     bool
     default y
     select CPU_MODEL_RP2040
+    select HAS_PERIPH_I2C
     select HAS_PERIPH_UART
 
     select HAVE_SAUL_GPIO
diff --git a/boards/rpi-pico/Makefile.features b/boards/rpi-pico/Makefile.features
@@ -1,5 +1,6 @@
 CPU := rpx0xx
 
 # Put defined MCU peripherals here (in alphabetical order)
+FEATURES_PROVIDED += periph_i2c
 FEATURES_PROVIDED += periph_timer
 FEATURES_PROVIDED += periph_uart
diff --git a/boards/rpi-pico/include/periph_conf.h b/boards/rpi-pico/include/periph_conf.h
@@ -78,6 +78,16 @@ static const timer_conf_t timer_config[] = {
 
 #define TIMER_NUMOF     ARRAY_SIZE(timer_config)
 
+/**
+ * @name    I2C configuration
+ * @{
+ */
+/**
+ *  @brief  Number of I2C interfaces
+ */
+#define I2C_NUMOF       0
+/** @} */
+
 /**
  * @name    PIO configuration
  * @{
@@ -107,6 +117,24 @@ static const pio_conf_t pio_config[] = {
 #define PIO_SM_NUMOF    4                       /**< Number of state machines per PIO */
 #define PIO_INSTR_NUMOF 32                      /**< Maximum number of instructions */
 #define PIO_IRQ_NUMOF   8                       /**< Number of interrupt flags per PIO */
+
+#if defined(PIO_I2C_CONFIG) || defined(DOXYGEN)
+/**
+ * @brief   PIO I2C configuration
+ *
+ * PIO_I2C_CONFIG should be defined during the build process to fit
+ * the users pin selection.
+ */
+static const pio_i2c_conf_t pio_i2c_config[] = {
+    PIO_I2C_CONFIG
+};
+/**
+ * @brief   Number of PIO I2C configurations
+ */
+#define PIO_I2C_NUMOF   ARRAY_SIZE(pio_i2c_config)
+#else
+#define pio_i2c_config  ((pio_i2c_conf_t *)NULL)
+#endif
 /** @} */
 
 #ifdef __cplusplus

diff --git a/cpu/rpx0xx/Kconfig b/cpu/rpx0xx/Kconfig
@@ -16,6 +16,7 @@ config CPU_FAM_RPX0XX
     select HAS_PERIPH_TIMER_PERIODIC
     select HAS_PERIPH_UART_MODECFG
     select HAS_PERIPH_UART_RECONFIGURE
+    select HAS_PIO_I2C
 
 config CPU_FAM
     default "RPX0XX" if CPU_FAM_RPX0XX

diff --git a/cpu/rpx0xx/Makefile b/cpu/rpx0xx/Makefile
@@ -2,4 +2,8 @@ MODULE = cpu
 
 DIRS = $(RIOTCPU)/cortexm_common periph
 
+ifneq (,$(filter pio_i2c,$(USEMODULE)))
+  DIRS += pio/i2c
+endif
+
 include $(RIOTBASE)/Makefile.base
diff --git a/cpu/rpx0xx/Makefile.dep b/cpu/rpx0xx/Makefile.dep
@@ -2,4 +2,9 @@ ifneq (,$(filter pio_%,$(USEMODULE)))
   USEMODULE += periph_pio
 endif
 
+ifneq (,$(filter pio_i2c periph_i2c,$(FEATURES_USED)))
+  DEFAULT_MODULE += pio_autostart_i2c
+  USEMODULE += pio_i2c
+endif
+
 include $(RIOTCPU)/cortexm_common/Makefile.dep
diff --git a/cpu/rpx0xx/Makefile.features b/cpu/rpx0xx/Makefile.features
@@ -9,3 +9,4 @@ FEATURES_PROVIDED += periph_pio
 FEATURES_PROVIDED += periph_timer_periodic
 FEATURES_PROVIDED += periph_uart_reconfigure
 FEATURES_PROVIDED += periph_uart_modecfg
+FEATURES_PROVIDED += pio_i2c
diff --git a/cpu/rpx0xx/include/periph_cpu.h b/cpu/rpx0xx/include/periph_cpu.h
@@ -432,6 +432,15 @@ typedef struct {
     IRQn_Type irqn1;                /**< PIO IRQ1 interrupt number */
 } pio_conf_t;
 
+/**
+ * @brief   PIO I2C configuration type
+ */
+typedef struct {
+    gpio_t sda;                     /**< Pin to use as SDA pin */
+    gpio_t scl;                     /**< Pin to use as SCL pin */
+    unsigned irq;                   /**< PIO IRQ line to use */
+} pio_i2c_conf_t;
+
 /**
  * @brief   Get the PAD control register for the given GPIO pin as word
  *

diff --git a/cpu/rpx0xx/periph/i2c.c b/cpu/rpx0xx/periph/i2c.c
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2021 Otto-von-Guericke Universität Magdeburg
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     cpu_rpx0xx
+ * @ingroup     drivers_periph_i2c
+ * @{
+ *
+ * @file
+ * @brief       Low-level I2C driver implementation
+ *
+ * @note        This driver is so far only a dummy implementation
+ *              to test the PIO I2C interface.
+ *
+ * @author      Fabian Hüßler <fabian.huessler@ovgu.de>
+ * @}
+ */
+
+#include <errno.h>
+
+#include "periph_conf.h"
+#include "periph/i2c.h"
+#include "periph/pio/i2c.h"
+
+int i2c_acquire(i2c_t dev)
+{
+    if (IS_USED(MODULE_PIO_I2C) && (int)dev >= I2C_NUMOF) {
+        pio_i2c_obj_t *i2c = pio_i2c_get(dev - I2C_NUMOF);
+        return i2c ? pio_i2c_acquire(&i2c->pro) : -EFAULT;
+    }
+    return -ENOTSUP;
+}
+
+void i2c_release(i2c_t dev)
+{
+    if (IS_USED(MODULE_PIO_I2C) && (int)dev >= I2C_NUMOF) {
+        pio_i2c_obj_t *i2c = pio_i2c_get(dev - I2C_NUMOF);
+        if (i2c) {
+            pio_i2c_release(&i2c->pro);
+        }
+    }
+}
+
+int i2c_read_bytes(i2c_t dev, uint16_t addr, void *data,
+                   size_t len, uint8_t flags)
+{
+    if (IS_USED(MODULE_PIO_I2C) && (int)dev >= I2C_NUMOF) {
+        pio_i2c_obj_t *i2c = pio_i2c_get(dev - I2C_NUMOF);
+        return i2c ? pio_i2c_read_bytes(i2c->pio, i2c->sm, addr, data, len, flags) : -EFAULT;
+    }
+    return -ENOTSUP;
+}
+
+int i2c_read_regs(i2c_t dev, uint16_t addr, uint16_t reg,
+                  void *data, size_t len, uint8_t flags)
+{
+    if (IS_USED(MODULE_PIO_I2C) && (int)dev >= I2C_NUMOF) {
+        pio_i2c_obj_t *i2c = pio_i2c_get(dev - I2C_NUMOF);
+        return i2c ? pio_i2c_read_regs(i2c->pio, i2c->sm, addr, reg, data, len, flags) : -EFAULT;
+    }
+    return -ENOTSUP;
+}
+
+int i2c_read_reg(i2c_t dev, uint16_t addr, uint16_t reg,
+                 void *data, uint8_t flags)
+{
+    return i2c_read_regs(dev, addr, reg, data, 1, flags);
+}
+
+int i2c_write_bytes(i2c_t dev, uint16_t addr, const void *data,
+                    size_t len, uint8_t flags)
+{
+    if (IS_USED(MODULE_PIO_I2C) && (int)dev >= I2C_NUMOF) {
+        pio_i2c_obj_t *i2c = pio_i2c_get(dev - I2C_NUMOF);
+        return i2c ? pio_i2c_write_bytes(i2c->pio, i2c->sm, addr, data, len, flags) : -EFAULT;
+    }
+    return -ENOTSUP;
+}
+
+int i2c_write_regs(i2c_t dev, uint16_t addr, uint16_t reg,
+                   const void *data, size_t len, uint8_t flags)
+{
+    if (IS_USED(MODULE_PIO_I2C) && (int)dev >= I2C_NUMOF) {
+        pio_i2c_obj_t *i2c = pio_i2c_get(dev - I2C_NUMOF);
+        return i2c ? pio_i2c_write_regs(i2c->pio, i2c->sm, addr, reg, data, len, flags) : -EFAULT;
+    }
+    return -ENOTSUP;
+}
+
+int i2c_write_reg(i2c_t dev, uint16_t addr, uint16_t reg,
+                  uint8_t data, uint8_t flags)
+{
+    return i2c_write_regs(dev, addr, reg, &data, 1, flags);
+}
diff --git a/cpu/rpx0xx/periph/pio.c b/cpu/rpx0xx/periph/pio.c
@@ -28,6 +28,7 @@
 #include "periph_cpu.h"
 #include "io_reg.h"
 #include "pio/pio.h"
+#include "periph/pio/i2c.h"
 #define ENABLE_DEBUG 0
 #include "debug.h"
 
@@ -132,6 +133,10 @@ void pio_init(pio_t pio)
 
 void pio_start_programs(void)
 {
+    if (IS_USED(MODULE_PIO_AUTOSTART_I2C)) {
+        pio_i2c_init_programs();
+        pio_i2c_start_programs();
+    }
 }
 
 pio_sm_t pio_sm_lock(pio_t pio)

diff --git a/cpu/rpx0xx/pio/i2c/Makefile b/cpu/rpx0xx/pio/i2c/Makefile
@@ -0,0 +1,11 @@
+MODULE = pio_i2c
+
+include $(RIOTBASE)/Makefile.base
+
+i2c.c: i2c.hex.pio.h i2c_set_scl_sda.hex.pio.h
+
+i2c.hex.pio.h: i2c.pio
+	$(Q) $(RIOTCPU)/$(CPU)/dist/pioasm.bash $< $@
+
+i2c_set_scl_sda.hex.pio.h: i2c_set_scl_sda.pio
+	$(Q) $(RIOTCPU)/$(CPU)/dist/pioasm.bash $< $@