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/*
* RTEMS driver for Blackfin UARTs
*
* COPYRIGHT (c) 2008 Kallisti Labs, Los Gatos, CA, USA
* written by Allan Hessenflow <allanh@kallisti.com>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#ifndef _UART_H_
#define _UART_H_
#ifdef __cplusplus
extern "C" {
#endif
/** bfin_uart_channel object
*/
typedef struct {
const char *name; /** Holds name of the device */
uint32_t uart_baseAddress; /** UART base address */
uint32_t uart_rxDmaBaseAddress; /** RX DMA base address */
uint32_t uart_txDmaBaseAddress; /** TX DMA base address */
bool uart_useInterrupts; /** are interrupts used */
bool uart_useDma; /** is dma used */
int uart_baud; /** baud rate, 0 for default */
void *termios; /** termios associated */
uint8_t volatile flags; /** flags for internal use */
uint16_t length; /** length for internal use */
} bfin_uart_channel_t;
typedef struct {
uint32_t freq;
int num_channels;
bfin_uart_channel_t *channels;
} bfin_uart_config_t;
/**
* @param base_address defines the UART base address
* @param source defines the source that caused the interrupt. This argument
* will help us in identifying if Rx or TX caused the interrupt.
*/
typedef struct {
uint32_t base_address;
int source;
} bfin_uart_arg_t;
char bfin_uart_poll_read(rtems_device_minor_number minor);
void bfin_uart_poll_write(int minor, char c);
/**
* Uart initialization function.
* @param major major number of the device
* @param config configuration parameters
* @return rtems status code
*/
rtems_status_code bfin_uart_initialize(rtems_device_major_number major,
bfin_uart_config_t *config);
/**
* Opens the device in different modes. The supported modes are
* 1. Polling
* 2. Interrupt
* 3. DMA
* At exit the uart_Exit function will be called to flush the device.
*
* @param major Major number of the device
* @param minor Minor number of the device
* @param arg
* @return
*/
rtems_device_driver bfin_uart_open(rtems_device_major_number major,
rtems_device_minor_number minor, void *arg);
/**
* This function implements TX dma ISR. It clears the IRQ and dequeues a char
* The channel argument will have the base address. Since there are two uart
* and both the uarts can use the same tx dma isr.
*
* TODO: 1. Error checking 2. sending correct length ie after looking at the
* number of elements the uart transmitted.
*
* @param _arg argument passed to the interrupt handler. It contains the
* channel argument.
*/
void bfinUart_txDmaIsr(void *_arg);
/**
* RX DMA ISR.
* The polling route is used for receiving the characters. This is a place
* holder for future implementation.
* @param _arg
*/
void bfinUart_rxDmaIsr(void *_arg);
/**
* This function implements TX ISR. The function gets called when the TX FIFO is
* empty. It clears the interrupt and dequeues the character. It only tx one
* character at a time.
*
* TODO: error handling.
* @param _arg gets the channel information.
*/
void bfinUart_txIsr(void *_arg);
/**
* This function implements RX ISR
*/
void bfinUart_rxIsr(void *_arg);
#ifdef __cplusplus
}
#endif
#endif /* _UART_H_ */
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