Import of the watch repository from Pebble

platform/robert/boot/src/drivers/i2c/i2c_definitions.h

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+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+typedef enum I2CTransferEvent {
+  I2CTransferEvent_Timeout,
+  I2CTransferEvent_TransferComplete,
+  I2CTransferEvent_NackReceived,
+  I2CTransferEvent_Error,
+} I2CTransferEvent;
+
+typedef enum {
+  I2CTransferDirection_Read,
+  I2CTransferDirection_Write
+} I2CTransferDirection;
+
+typedef enum {
+  // Send a register address, followed by a repeat start for reads
+  I2CTransferType_SendRegisterAddress,
+
+  // Do not send a register address; used for block writes/reads
+  I2CTransferType_NoRegisterAddress
+} I2CTransferType;
+
+typedef enum I2CTransferState {
+  I2CTransferState_WriteAddressTx,
+  I2CTransferState_WriteRegAddress,
+  I2CTransferState_RepeatStart,
+  I2CTransferState_WriteAddressRx,
+  I2CTransferState_WaitForData,
+  I2CTransferState_ReadData,
+  I2CTransferState_WriteData,
+  I2CTransferState_EndWrite,
+  I2CTransferState_Complete,
+} I2CTransferState;
+
+typedef struct I2CTransfer {
+  I2CTransferState state;
+  uint16_t device_address;
+  I2CTransferDirection direction;
+  I2CTransferType type;
+  uint8_t register_address;
+  uint32_t size;
+  uint32_t idx;
+  uint8_t *data;
+} I2CTransfer;
+
+typedef struct I2CBusState {
+  I2CTransfer transfer;
+  I2CTransferEvent transfer_event;
+  int transfer_nack_count;
+  int user_count;
+  volatile bool busy;
+} I2CBusState;
+
+struct I2CBus {
+  I2CBusState *const state;
+  const struct I2CBusHal *const hal;
+  AfConfig scl_gpio;  ///< Alternate Function configuration for SCL pin
+  AfConfig sda_gpio;  ///< Alternate Function configuration for SDA pin
+  OutputConfig rail_gpio;  ///< Control pin for rail
+  void (* const rail_ctl_fn)(I2CBus *device, bool enabled); ///< Control function for this rail.
+  const char *name;  //! Device ID for logging purposes
+};
+
+struct I2CSlavePort {
+  const I2CBus *bus;
+  uint16_t address;
+};
+
+//! Initialize the I2C driver.
+void i2c_init(I2CBus *bus);
+
+//! Transfer event handler implemented in i2c.c and called by HAL implementation
+void i2c_handle_transfer_event(I2CBus *device, I2CTransferEvent event);
+
+#define I2C_DEBUG(fmt, args...) \
+  PBL_LOG_COLOR_D(LOG_DOMAIN_I2C, LOG_LEVEL_DEBUG, LOG_COLOR_LIGHT_MAGENTA, fmt, ## args)