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最近閱讀了davinci新版舊版內(nèi)核的DMA驅(qū)動(dòng)那塊，再回頭查看應(yīng)用程序中關(guān)于DMA調(diào)用接口部分，將兩個(gè)版本內(nèi)核DMA調(diào)用接口捋出對(duì)比了一下， 只是大概備注了一下，其實(shí)接口很簡(jiǎn)單，但DMA具體操作很復(fù)雜，光是EDMA的datasheet就有150多頁(yè)，懶得看，所以有誤的地方就沒去在乎，僅作參 考。關(guān)于I2C接口部分稍后貼出...... 2.6.10內(nèi)核DMA函數(shù) 1.申請(qǐng)DMA通道 result = davinci_request_dma (EDMA_QDMA_CHANNEL_ANY, "A-SYNC_DMA0", callback1, NULL, &qdma_ch, &tcc, event_queue); 2.6.32內(nèi)核DMA函數(shù) 1.申請(qǐng)DMA通道 dma_ch1 = edma_alloc_channel(EDMA_CHANNEL_ANY, callback1, NULL, event_queue); --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.設(shè)置dmaphyssrc1地址作為DMA通道的數(shù)據(jù)源 davinci_set_dma_src_params (qdma_ch, (unsigned long)(dmaphyssrc1), INCR, W8BIT); 2.6.32內(nèi)核DMA函數(shù) 1.設(shè)置dmaphyssrc1地址作為DMA通道要傳輸?shù)臄?shù)據(jù)源 edma_set_src(dma_ch1, (unsigned long)(dmaphyssrc1), INCR, W8BIT); --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.設(shè)置dmaphysdest1地址作為DMA通道要傳輸數(shù)據(jù)的目的地 davinci_set_dma_dest_params (qdma_ch, (unsigned long)(dmaphysdest1), INCR, W8BIT); 2.6.32內(nèi)核DMA函數(shù) 1.設(shè)置dmaphysdest1地址作為DMA通道要傳輸數(shù)據(jù)的目的地 edma_set_dest(dma_ch1, (unsigned long)(dmaphysdest1), INCR, W8BIT); --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.設(shè)置srcbidx、srccidx作為DMA通道源B-C寄存器的序號(hào) davinci_set_dma_src_index (qdma_ch, srcbidx, srccidx); /****************************************************************************** * * DMA source index setup * ARGUMENTS: * lch - channel or param device for configuration of source index * srcbidx - source B-register index * srccidx - source C-register index * *****************************************************************************/ 2.6.32內(nèi)核DMA函數(shù) 1.設(shè)置srcbidx、srccidx作為DMA通道源B-C寄存器的序號(hào) edma_set_src_index(dma_ch1, srcbidx, srccidx); --------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.設(shè)置desbidx、descidx作為DMA通道目的B-C寄存器的序號(hào) davinci_set_dma_dest_index (qdma_ch, desbidx, descidx); /****************************************************************************** * * DMA source index setup * ARGUMENTS: * lch - channel or param device for configuration of source index * srcbidx - source B-register index * srccidx - source C-register index * *****************************************************************************/ 2.6.32內(nèi)核DMA函數(shù) 1.設(shè)置desbidx、descidx作為DMA通道目的B-C寄存器的序號(hào) edma_set_dest_index(dma_ch1, desbidx, descidx); --------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.獲取DMA通道的參數(shù) davinci_get_dma_params (qdma_ch, ¶m_set); /****************************************************************************** * * DMA source index setup * ARGUMENTS: * lch - channel or param device for configuration of source index * srcbidx - source B-register index * srccidx - source C-register index * *****************************************************************************/ 2.6.32內(nèi)核DMA函數(shù) 1.獲取DMA通道的參數(shù) edma_read_slot(dma_ch1, ¶m_set); /* Enable the Interrupts on Channel 1 */ edma_read_slot(dma_ch1, ¶m_set); param_set.opt |= (1 << ITCINTEN_SHIFT); param_set.opt |= (1 << TCINTEN_SHIFT); param_set.opt |= EDMA_TCC(EDMA_CHAN_SLOT(dma_ch1)); --------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.設(shè)置DMA通道的參數(shù) davinci_set_dma_params(dma_ch1, ¶m_set); /****************************************************************************** * * DMA source index setup * ARGUMENTS: * lch - channel or param device for configuration of source index * srcbidx - source B-register index * srccidx - source C-register index * *****************************************************************************/ 2.6.32內(nèi)核DMA函數(shù) 1.設(shè)置DMA通道的參數(shù) edma_write_slot(dma_ch1, ¶m_set); /* Enable the Interrupts on Channel 1 */ edma_read_slot(dma_ch1, ¶m_set); param_set.opt |= (1 << ITCINTEN_SHIFT); param_set.opt |= (1 << TCINTEN_SHIFT); param_set.opt |= EDMA_TCC(EDMA_CHAN_SLOT(dma_ch1)); edma_write_slot(dma_ch1, ¶m_set); --------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.設(shè)置DMA通道傳輸模式 davinci_set_dma_transfer_params (dma_ch2, acnt, bcnt, ccnt, BRCnt, ASYNC); /****************************************************************************** * * DMA transfer parameters setup * ARGUMENTS: * lch - channel or param device for configuration of aCount, bCount and * cCount regs. * acnt - acnt register value to be configured * bcnt - bcnt register value to be configured * ccnt - ccnt register value to be configured * *****************************************************************************/ void davinci_set_dma_transfer_params(int lch, unsigned short acnt, unsigned short bcnt, unsigned short ccnt, unsigned short bcntrld, enum sync_dimension sync_mode) 2.6.32內(nèi)核DMA函數(shù) 1.設(shè)置DMA通道傳輸模式 edma_set_transfer_params(dma_ch2, acnt, bcnt, ccnt, BRCnt, ASYNC); void edma_set_transfer_params(unsigned slot, u16 acnt, u16 bcnt, u16 ccnt, u16 bcnt_rld, enum sync_dimension sync_mode) /** * edma_set_transfer_params - configure DMA transfer parameters * @slot: parameter RAM slot being configured * @acnt: how many bytes per array (at least one) * @bcnt: how many arrays per frame (at least one) * @ccnt: how many frames per block (at least one) * @bcnt_rld: used only for A-Synchronized transfers; this specifies * the value to reload into bcnt when it decrements to zero * @sync_mode: ASYNC or ABSYNC **/ --------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.連接dma_ch1和dma_ch2兩個(gè)通道 davinci_dma_link_lch(dma_ch1, dma_ch2); void davinci_dma_link_lch(int lch_head, int lch_queue) /****************************************************************************** * * DMA channel link - link the two logical channels passed through by linking * the link field of head to the param pointed by the lch_queue. * ARGUMENTS: * lch_head - logical channel number, in which the link field is linked * to the param pointed to by lch_queue * lch_queue - logical channel number or the param entry number, which is to be * linked to the lch_head ******************************************************************************/ 2.6.32內(nèi)核DMA函數(shù) 1.連接dma_ch1和dma_ch2兩個(gè)通道 /* Link both the channels */ edma_link(dma_ch1, dma_ch2); --------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.開始DMA傳輸 result = davinci_start_dma(dma_ch1); /****************************************************************************** * * DMA Start - Starts the dma on the channel passed * ARGUMENTS: * lch - logical channel number * *****************************************************************************/ int davinci_start_dma(int lch) 2.6.32內(nèi)核DMA函數(shù) 1.開始DMA傳輸 result = davinci_start_dma(dma_ch1); --------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.停止DMA通道 davinci_stop_dma(dma_ch1); 2.6.32內(nèi)核DMA函數(shù) 1.停止DMA通道 edma_stop(dma_ch1); edma_clean_channel(dma_ch1); --------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------- 2.6.10內(nèi)核DMA函數(shù) 1.釋放DMA通道 davinci_free_dma(dma_ch1); 2.6.32內(nèi)核DMA函數(shù) 1.停止DMA通道 edma_free_slot(dma_ch1); edma_free_channel(dma_ch1); --------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------- |
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