diff options
Diffstat (limited to 'include/dev/i2c/i2c.h')
| -rw-r--r-- | include/dev/i2c/i2c.h | 432 |
1 files changed, 432 insertions, 0 deletions
diff --git a/include/dev/i2c/i2c.h b/include/dev/i2c/i2c.h new file mode 100644 index 0000000000..2ace4fcf64 --- /dev/null +++ b/include/dev/i2c/i2c.h @@ -0,0 +1,432 @@ +/** + * @file + * + * @brief Inter-Integrated Circuit (I2C) Driver API + * + * @ingroup I2C + */ + +/* + * Copyright (c) 2014 embedded brains GmbH. All rights reserved. + * + * embedded brains GmbH + * Dornierstr. 4 + * 82178 Puchheim + * Germany + * <rtems@embedded-brains.de> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#ifndef _DEV_I2C_I2C_H +#define _DEV_I2C_I2C_H + +#include <linux/i2c.h> +#include <linux/i2c-dev.h> + +#include <rtems.h> +#include <rtems/seterr.h> + +#include <sys/ioctl.h> +#include <sys/stat.h> + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +typedef struct i2c_msg i2c_msg; + +typedef struct i2c_bus i2c_bus; + +typedef struct i2c_dev i2c_dev; + +typedef struct i2c_rdwr_ioctl_data i2c_rdwr_ioctl_data; + +/** + * @defgroup I2C Inter-Integrated Circuit (I2C) Driver + * + * @brief Inter-Integrated Circuit (I2C) bus and device driver support. + * + * @{ + */ + +/** + * @defgroup I2CBus I2C Bus Driver + * + * @ingroup I2C + * + * @{ + */ + +/** + * @name I2C IO Control Commands + * + * @{ + */ + +/** + * @brief Obtains the bus. + * + * This command has no argument. + */ +#define I2C_BUS_OBTAIN 0x800 + +/** + * @brief Releases the bus. + * + * This command has no argument. + */ +#define I2C_BUS_RELEASE 0x801 + +/** + * @brief Gets the bus control. + * + * The argument type is a pointer to i2c_bus pointer. + */ +#define I2C_BUS_GET_CONTROL 0x802 + +/** + * @brief Sets the bus clock in Hz. + * + * The argument type is unsigned long. + */ +#define I2C_BUS_SET_CLOCK 0x803 + +/** @} */ + +/** + * @brief Default I2C bus clock in Hz. + */ +#define I2C_BUS_CLOCK_DEFAULT 100000 + +/** + * @brief I2C bus control. + */ +struct i2c_bus { + /** + * @brief Transfers I2C messages. + * + * @param[in] bus The bus control. + * @param[in] msgs The messages to transfer. + * @param[in] msg_count The count of messages to transfer. It must be + * positive. + * + * @retval 0 Successful operation. + * @retval negative Negative error number in case of an error. + */ + int (*transfer)(i2c_bus *bus, i2c_msg *msgs, uint32_t msg_count); + + /** + * @brief Sets the bus clock. + * + * @param[in] bus The bus control. + * @param[in] clock The desired bus clock in Hz. + * + * @retval 0 Successful operation. + * @retval negative Negative error number in case of an error. + */ + int (*set_clock)(i2c_bus *bus, unsigned long clock); + + /** + * @brief Destroys the bus. + * + * @param[in] bus The bus control. + */ + void (*destroy)(i2c_bus *bus); + + /** + * @brief Mutex to protect the bus access. + */ + rtems_id mutex; + + /** + * @brief Default slave device address. + */ + uint16_t default_address; + + /** + * @brief Use 10-bit addresses. + */ + bool ten_bit_address; + + /** + * @brief Use SMBus PEC. + */ + bool use_pec; + + /** + * @brief Transfer retry count. + */ + unsigned long retries; + + /** + * @brief Transaction timeout in ticks. + */ + rtems_interval timeout; + + /** + * @brief Controller functionality. + */ + unsigned long functionality; +}; + +/** + * @brief Initializes a bus control. + * + * After a sucessful initialization the bus control must be destroyed via + * i2c_bus_destroy(). A registered bus control will be automatically destroyed + * in case the device file is unlinked. Make sure to call i2c_bus_destroy() in + * a custom destruction handler. + * + * @param[in] bus The bus control. + * + * @retval 0 Successful operation. + * @retval -1 An error occurred. The errno is set to indicate the error. + * + * @see i2c_bus_register() + */ +int i2c_bus_init(i2c_bus *bus); + +/** + * @brief Allocates a bus control from the heap and initializes it. + * + * After a sucessful allocation and initialization the bus control must be + * destroyed via i2c_bus_destroy_and_free(). A registered bus control will be + * automatically destroyed in case the device file is unlinked. Make sure to + * call i2c_bus_destroy_and_free() in a custom destruction handler. + * + * @param[in] size The size of the bus control. This enables the addition of + * bus controller specific data to the base bus control. The bus control is + * zero initialized. + * + * @retval non-NULL The new bus control. + * @retval NULL An error occurred. The errno is set to indicate the error. + * + * @see i2c_bus_register() + */ +i2c_bus *i2c_bus_alloc_and_init(size_t size); + +/** + * @brief Destroys a bus control. + * + * @param[in] bus The bus control. + */ +void i2c_bus_destroy(i2c_bus *bus); + +/** + * @brief Destroys a bus control and frees its memory. + * + * @param[in] bus The bus control. + */ +void i2c_bus_destroy_and_free(i2c_bus *bus); + +/** + * @brief Registers a bus control. + * + * This function claims ownership of the bus control regardless if the + * registration is successful or not. + * + * @param[in] bus The bus control. + * @param[in] bus_path The path to the bus device file. + * + * @retval 0 Successful operation. + * @retval -1 An error occurred. The errno is set to indicate the error. + */ +int i2c_bus_register( + i2c_bus *bus, + const char *bus_path +); + +/** + * @brief Obtains the bus. + * + * @param[in] bus The bus control. + */ +void i2c_bus_obtain(i2c_bus *bus); + +/** + * @brief Releases the bus. + * + * @param[in] bus The bus control. + */ +void i2c_bus_release(i2c_bus *bus); + +/** + * @brief Transfers I2C messages. + * + * The bus is obtained before the transfer and released afterwards. + * + * @param[in] bus The bus control. + * @param[in] msgs The messages to transfer. + * @param[in] msg_count The count of messages to transfer. It must be + * positive. + * + * @retval 0 Successful operation. + * @retval negative Negative error number in case of an error. + */ +int i2c_bus_transfer(i2c_bus *bus, i2c_msg *msgs, uint32_t msg_count); + +/** @} */ + +/** + * @defgroup I2CDevice I2C Device Driver + * + * @ingroup I2C + * + * @{ + */ + +/** + * @brief Base number for device IO control commands. + */ +#define I2C_DEV_IO_CONTROL 0x900 + +/** + * @brief I2C slave device control. + */ +struct i2c_dev { + /** + * @brief Reads from the device. + * + * @retval non-negative Bytes transferred from device. + * @retval negative Negative error number in case of an error. + */ + ssize_t (*read)(i2c_dev *dev, void *buf, size_t n, off_t offset); + + /** + * @brief Writes to the device. + * + * @retval non-negative Bytes transferred to device. + * @retval negative Negative error number in case of an error. + */ + ssize_t (*write)(i2c_dev *dev, const void *buf, size_t n, off_t offset); + + /** + * @brief Device IO control. + * + * @retval 0 Successful operation. + * @retval negative Negative error number in case of an error. + */ + int (*ioctl)(i2c_dev *dev, ioctl_command_t command, void *arg); + + /** + * @brief Gets the file size. + */ + off_t (*get_size)(i2c_dev *dev); + + /** + * @brief Gets the file block size. + */ + blksize_t (*get_block_size)(i2c_dev *dev); + + /** + * @brief Destroys the device. + */ + void (*destroy)(i2c_dev *dev); + + /** + * @brief The bus control. + */ + i2c_bus *bus; + + /** + * @brief The device address. + */ + uint16_t address; + + /** + * @brief File descriptor of the bus. + * + * This prevents destruction of the bus since we hold a reference to it with + * this. + */ + int bus_fd; +}; + + +/** + * @brief Initializes a device control. + * + * After a sucessful initialization the device control must be destroyed via + * i2c_dev_destroy(). A registered device control will be automatically + * destroyed in case the device file is unlinked. Make sure to call + * i2c_dev_destroy_and_free() in a custom destruction handler. + * + * @param[in] device The device control. + * @param[in] bus_path The path to the bus device file. + * @param[in] address The address of the device. + * + * @retval 0 Successful operation. + * @retval -1 An error occurred. The errno is set to indicate the error. + * + * @see i2c_dev_register() + */ +int i2c_dev_init(i2c_dev *dev, const char *bus_path, uint16_t address); + +/** + * @brief Allocates a device control from the heap and initializes it. + * + * After a sucessful allocation and initialization the device control must be + * destroyed via i2c_dev_destroy_and_free(). A registered device control will + * be automatically destroyed in case the device file is unlinked. Make sure + * to call i2c_dev_destroy_and_free() in a custom destruction handler. + * + * @param[in] size The size of the device control. This enables the addition + * of device specific data to the base device control. The device control is + * zero initialized. + * @param[in] bus_path The path to the bus device file. + * @param[in] address The address of the device. + * + * @retval non-NULL The new device control. + * @retval NULL An error occurred. The errno is set to indicate the error. + * + * @see i2c_dev_register() + */ +i2c_dev *i2c_dev_alloc_and_init( + size_t size, + const char *bus_path, + uint16_t address +); + +/** + * @brief Destroys a device control. + * + * @param[in] dev The device control. + */ +void i2c_dev_destroy(i2c_dev *dev); + +/** + * @brief Destroys a device control and frees its memory. + * + * @param[in] dev The device control. + */ +void i2c_dev_destroy_and_free(i2c_dev *dev); + +/** + * @brief Registers a device control. + * + * This function claims ownership of the device control regardless if the + * registration is successful or not. + * + * @param[in] dev The dev control. + * @param[in] dev_path The path to the device file of the device. + * + * @retval 0 Successful operation. + * @retval -1 An error occurred. The errno is set to indicate the error. + */ +int i2c_dev_register( + i2c_dev *dev, + const char *dev_path +); + +/** @} */ /* end of i2c device driver */ + +/** @} */ + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* _DEV_I2C_I2C_H */ |