diff options
Diffstat (limited to 'bsps/arm/lpc176x/start/dma-copy.c')
| -rw-r--r-- | bsps/arm/lpc176x/start/dma-copy.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/bsps/arm/lpc176x/start/dma-copy.c b/bsps/arm/lpc176x/start/dma-copy.c new file mode 100644 index 0000000000..0e0b37dbd3 --- /dev/null +++ b/bsps/arm/lpc176x/start/dma-copy.c @@ -0,0 +1,220 @@ +/** + * @file + * + * @ingroup lpc176x_dma + * + * @brief Direct memory access (DMA) support. + */ + +/* + * Copyright (c) 2008, 2009 + * embedded brains GmbH + * Obere Lagerstr. 30 + * D-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. + */ + +#include <bsp/lpc176x.h> +#include <bsp/dma.h> +#include <bsp/irq.h> + +static rtems_id lpc176x_dma_sema_table[ GPDMA_CH_NUMBER ]; +static bool lpc176x_dma_status_table[ GPDMA_CH_NUMBER ]; + +static void lpc176x_dma_copy_handler( void *arg ) +{ + /* Get interrupt status */ + uint32_t tc = GPDMA_INT_TCSTAT; + uint32_t err = GPDMA_INT_ERR_STAT; + + /* Clear interrupt status */ + GPDMA_INT_TCCLR = tc; + GPDMA_INT_ERR_CLR = err; + + if ( ( tc & GPDMA_STATUS_CH_0 ) != 0 ) { + rtems_semaphore_release( lpc176x_dma_sema_table[ 0 ] ); + } + + /* else implies that the channel is not the 0. Also, + there is nothing to do. */ + + lpc176x_dma_status_table[ 0 ] = ( err & GPDMA_STATUS_CH_0 ) == 0; + + if ( ( tc & GPDMA_STATUS_CH_1 ) != 0 ) { + rtems_semaphore_release( lpc176x_dma_sema_table[ 1 ] ); + } + + /* else implies that the channel is not the 1. Also, + there is nothing to do. */ + + lpc176x_dma_status_table[ 1 ] = ( err & GPDMA_STATUS_CH_1 ) == 0; +} + +rtems_status_code lpc176x_dma_copy_initialize( void ) +{ + rtems_status_code status_code = RTEMS_SUCCESSFUL; + rtems_id id0 = RTEMS_ID_NONE; + rtems_id id1 = RTEMS_ID_NONE; + + /* Create semaphore for channel 0 */ + status_code = rtems_semaphore_create( rtems_build_name( 'D', 'M', 'A', '0' ), + 0, + RTEMS_LOCAL | RTEMS_FIFO | RTEMS_SIMPLE_BINARY_SEMAPHORE, + 0, + &id0 ); + + if ( status_code != RTEMS_SUCCESSFUL ) { + return status_code; + } + + /* else implies that the semaphore to the channel 0 was created succefully. + Also, there is nothing to do. */ + + /* Create semaphore for channel 1 */ + status_code = rtems_semaphore_create( rtems_build_name( 'D', 'M', 'A', '1' ), + 0, + RTEMS_LOCAL | RTEMS_FIFO | RTEMS_SIMPLE_BINARY_SEMAPHORE, + 0, + &id1 ); + + if ( status_code != RTEMS_SUCCESSFUL ) { + rtems_semaphore_delete( id0 ); + + return status_code; + } + + /* else implies that the semaphore to the channel 1 was created succefully. + Also, there is nothing to do. */ + + /* Install DMA interrupt handler */ + status_code = rtems_interrupt_handler_install( LPC176X_IRQ_DMA, + "DMA copy", + RTEMS_INTERRUPT_UNIQUE, + lpc176x_dma_copy_handler, + NULL ); + + if ( status_code != RTEMS_SUCCESSFUL ) { + rtems_semaphore_delete( id0 ); + rtems_semaphore_delete( id1 ); + + return status_code; + } + + /* else implies that the interrupt handler was installed succefully. Also, + there is nothing to do. */ + + /* Initialize global data */ + lpc176x_dma_sema_table[ 0 ] = id0; + lpc176x_dma_sema_table[ 1 ] = id1; + + return RTEMS_SUCCESSFUL; +} + +rtems_status_code lpc176x_dma_copy_release( void ) +{ + rtems_status_code status_code = RTEMS_SUCCESSFUL; + rtems_status_code status_code_aux = RTEMS_SUCCESSFUL; + + status_code = rtems_interrupt_handler_remove( LPC176X_IRQ_DMA, + lpc176x_dma_copy_handler, + NULL ); + + if ( status_code != RTEMS_SUCCESSFUL ) { + status_code_aux = status_code; + } + + /* else implies that the interrupt handler was removed succefully. Also, + there is nothing to do. */ + + status_code = rtems_semaphore_delete( lpc176x_dma_sema_table[ 0 ] ); + + if ( status_code != RTEMS_SUCCESSFUL ) { + status_code_aux = status_code; + } + + /* else implies that the semaphore to the channel 0 was deleted succefully. + Also, there is nothing to do. */ + + status_code = rtems_semaphore_delete( lpc176x_dma_sema_table[ 1 ] ); + + if ( status_code != RTEMS_SUCCESSFUL ) { + status_code_aux = status_code; + } + + /* else implies that the semaphore to the channel 1 was deleted succefully. + Also, there is nothing to do. */ + + return status_code_aux; +} + +rtems_status_code lpc176x_dma_copy( + unsigned channel, + const void *const dest, + const void *const src, + size_t n, + const size_t width +) +{ + rtems_status_code status_code = RTEMS_SUCCESSFUL; + volatile lpc176x_dma_channel *e = GPDMA_CH_BASE_ADDR( channel ); + uint32_t w = GPDMA_CH_CTRL_W_8; + + switch ( width ) { + case 4: + w = GPDMA_CH_CTRL_W_32; + break; + case 2: + w = GPDMA_CH_CTRL_W_16; + break; + } + + n = n >> w; + + if ( n > 0 && n < 4096 ) { + e->desc.src = (uint32_t) src; + e->desc.dest = (uint32_t) dest; + e->desc.lli = 0; + e->desc.ctrl = SET_GPDMA_CH_CTRL_TSZ( 0, n ) | + SET_GPDMA_CH_CTRL_SBSZ( 0, GPDMA_CH_CTRL_BSZ_1 ) | + SET_GPDMA_CH_CTRL_DBSZ( 0, GPDMA_CH_CTRL_BSZ_1 ) | + SET_GPDMA_CH_CTRL_SW( 0, w ) | + SET_GPDMA_CH_CTRL_DW( 0, w ) | + GPDMA_CH_CTRL_ITC | + GPDMA_CH_CTRL_SI | + GPDMA_CH_CTRL_DI; + e->cfg = SET_GPDMA_CH_CFG_FLOW( 0, GPDMA_CH_CFG_FLOW_MEM_TO_MEM_DMA ) | + GPDMA_CH_CFG_IE | + GPDMA_CH_CFG_ITC | + GPDMA_CH_CFG_EN; + } else { + status_code = RTEMS_INVALID_SIZE; + } + + return status_code; +} + +rtems_status_code lpc176x_dma_copy_wait( const unsigned channel ) +{ + rtems_status_code status_code = RTEMS_SUCCESSFUL; + + status_code = rtems_semaphore_obtain( lpc176x_dma_sema_table[ channel ], + RTEMS_WAIT, + RTEMS_NO_TIMEOUT ); + + if ( status_code != RTEMS_SUCCESSFUL ) { + return status_code; + } + + /* else implies that the semaphore was obtained succefully. Also, + there is nothing to do. */ + + status_code = lpc176x_dma_status_table[ channel ] + ? RTEMS_SUCCESSFUL : RTEMS_IO_ERROR; + + return status_code; +} |