diff options
Diffstat (limited to 'os/hal/platforms/LPC17xx/dac_lld.c')
| -rw-r--r-- | os/hal/platforms/LPC17xx/dac_lld.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/os/hal/platforms/LPC17xx/dac_lld.c b/os/hal/platforms/LPC17xx/dac_lld.c new file mode 100644 index 000000000..11a423d69 --- /dev/null +++ b/os/hal/platforms/LPC17xx/dac_lld.c @@ -0,0 +1,210 @@ +/* + ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio + LPC17xx DAC driver - Copyright (C) 2013 Marcin Jokel + + 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. +*/ + +/** + * @file LPC17xx/dac_lld.c + * @brief LPC17xx DAC subsystem low level driver source. + * + * @addtogroup DAC + * @{ + */ + +#include "ch.h" +#include "hal.h" + +#if HAL_USE_DAC || defined(__DOXYGEN__) + +/*===========================================================================*/ +/* Driver local definitions. */ +/*===========================================================================*/ + +/*===========================================================================*/ +/* Driver exported variables. */ +/*===========================================================================*/ + +/** @brief CHN1 driver identifier.*/ +DACDriver DACD1; + +/*===========================================================================*/ +/* Driver local variables. */ +/*===========================================================================*/ + +static lpc17xx_dma_lli_config_t lpc_dac_lli[2] __attribute__((aligned(0x10))); + +/*===========================================================================*/ +/* Driver local functions. */ +/*===========================================================================*/ + + +/** + * @brief DAC DMA interrupt function. + * + * @param[in] dacp pointer to the @p DACDriver object + * @param[in] flags dma error flags + */ +static void dac_serve_dma_interrupt(DACDriver *dacp, uint32_t flags) { + + if ((flags & (1 << LPC17xx_DAC_DMA_CHANNEL)) != 0) { + _dac_isr_error_code(dacp, flags); /* DMA errors handling.*/ + } + else { + if (dacp->half_buffer == false) { + _dac_isr_half_code(dacp); + dacp->half_buffer = true; + } + else { + _dac_isr_full_code(dacp); + dacp->half_buffer = false; + } + } +} + +/*===========================================================================*/ +/* Driver interrupt handlers. */ +/*===========================================================================*/ + +/*===========================================================================*/ +/* Driver exported functions. */ +/*===========================================================================*/ + +/** + * @brief Low level DAC driver initialization. + * + * @notapi + */ +void dac_lld_init(void) { + dacObjectInit(&DACD1); +} + +/** + * @brief Configures and activates the DAC peripheral. + * + * @param[in] dacp pointer to the @p DACDriver object + * + * @notapi + */ +void dac_lld_start(DACDriver *dacp) { + + if (dacp->state == DAC_STOP) { + + /* Enable DAC */ + LPC_PINCON->PINSEL1 |= (2UL << 20); /* Set AOUT P0.26 pin.*/ + + LPC_DAC->CR = 0; + LPC_DAC->CTRL = 0; + LPC_DAC->CNTVAL = LPC17xx_PCLK/dacp->config->frequency; + + dmaChannelAllocate(LPC17xx_DAC_DMA_CHANNEL, \ + (lpc17xx_dmaisr_t)dac_serve_dma_interrupt, \ + (void *)dacp); + } +} + +/** + * @brief Deactivates the DAC peripheral. + * + * @param[in] dacp pointer to the @p DACDriver object + * + * @notapi + */ +void dac_lld_stop(DACDriver *dacp) { + + /* If in ready state then disables the DAC clock.*/ + if (dacp->state == DAC_READY) { + + /* DMA disable.*/ + dmaChannelDisable(LPC17xx_DAC_DMA_CHANNEL); + dmaChannelRelease(LPC17xx_DAC_DMA_CHANNEL); + + /* Disable DAC */ + LPC_PINCON->PINSEL1 &= ~(2UL << 20); /* Disable AOUT P0.26 pin.*/ + } +} + +/** + * @brief Sends data over the DAC bus. + * @details This asynchronous function starts a transmit operation. + * @post At the end of the operation the configured callback is invoked. + * + * @param[in] dacp pointer to the @p DACDriver object + * @param[in] n number of words to send + * @param[in] txbuf the pointer to the transmit buffer + * + * @notapi + */ +void dac_lld_start_conversion(DACDriver *dacp) { + + dacp->half_buffer = false; + uint32_t dma_ch_config; + + /* DMA configuration */ + lpc_dac_lli[0].srcaddr = (uint32_t) &dacp->samples[0]; + lpc_dac_lli[0].dstaddr = (uint32_t)&LPC_DAC->CR; + lpc_dac_lli[0].lli = (uint32_t) &lpc_dac_lli[1]; + lpc_dac_lli[0].control = + DMA_CTRL_TRANSFER_SIZE(dacp->depth/2) | + DMA_CTRL_SRC_BSIZE_1 | + DMA_CTRL_DST_BSIZE_1 | + DMA_CTRL_SRC_WIDTH_WORD | + DMA_CTRL_DST_WIDTH_WORD | + DMA_CTRL_SRC_INC | + DMA_CTRL_DST_NOINC | + DMA_CTRL_PROT1_USER | + DMA_CTRL_PROT2_NONBUFF | + DMA_CTRL_PROT3_NONCACHE | + DMA_CTRL_INT; + + lpc_dac_lli[1].srcaddr = (uint32_t) &dacp->samples[dacp->depth/2]; + lpc_dac_lli[1].dstaddr = lpc_dac_lli[0].dstaddr; + lpc_dac_lli[1].control = lpc_dac_lli[0].control; + + if (dacp->grpp->circular == true) { + lpc_dac_lli[1].lli = (uint32_t) &lpc_dac_lli[0]; + } + else { + lpc_dac_lli[1].lli = 0; + } + + dma_ch_config = + DMA_CFG_CH_ENABLE | + DMA_CFG_DST_PERIPH(DMA_DAC) | + DMA_CFG_TTYPE_M2P | + DMA_CFG_IE | + DMA_CFG_ITC; + + dmaChannelSrcAddr(LPC17xx_DAC_DMA_CHANNEL, lpc_dac_lli[0].srcaddr); + dmaChannelDstAddr(LPC17xx_DAC_DMA_CHANNEL, lpc_dac_lli[0].dstaddr); + dmaChannelLinkedList(LPC17xx_DAC_DMA_CHANNEL, lpc_dac_lli[0].lli); + dmaChannelControl(LPC17xx_DAC_DMA_CHANNEL, lpc_dac_lli[0].control); + dmaChannelConfig(LPC17xx_DAC_DMA_CHANNEL, dma_ch_config); + + LPC_DAC->CTRL = DACCTRL_DMA_ENA | DACCTRL_CNT_ENA | DACCTRL_DBLBUF_ENA; +} + +void dac_lld_stop_conversion(DACDriver *dacp) { + + /* If in active state then disables the DAC.*/ + if (dacp->state == DAC_ACTIVE) { + + /* DMA disable.*/ + dmaChannelDisable(LPC17xx_DAC_DMA_CHANNEL); + } +}; + +#endif /* HAL_USE_DAC */ + +/** @} */ |