d8fa0802f6
In order to have a more coherent DW AHB DMA slave configuration method - dwc_config() - let's simplify the source and destination channel max-burst calculation procedure: 1. Create the max-burst verification method as it has been just done for the memory and peripheral address widths. Thus the dwc_config() method will turn to a set of the verification methods execution. 2. Since both the generic DW AHB DMA and Intel iDMA 32-bit engines support the power-of-2 bursts only, then the specified by the client driver max-burst values can be converted to being power-of-2 right in the max-burst verification method. 3. Since max-burst encoded value is required on the CTL_LO fields calculation stage, the encode_maxburst() callback can be easily dropped from the dw_dma structure meanwhile the encoding procedure will be executed right in the CTL_LO register value calculation. Thus the update will provide the next positive effects: the internal DMA-slave config structure will contain only the real DMA-transfer config values, which will be encoded to the DMA-controller register fields only when it's required on the buffer mapping; the redundant encode_maxburst() callback will be dropped simplifying the internal HW-abstraction API; dwc_config() will look more readable executing the verification functions one-by-one. Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Acked-by: Andy Shevchenko <andy@kernel.org> Link: https://lore.kernel.org/r/20240802075100.6475-6-fancer.lancer@gmail.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
146 lines
3.6 KiB
C
146 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2007-2008 Atmel Corporation
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// Copyright (C) 2010-2011 ST Microelectronics
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// Copyright (C) 2013,2018 Intel Corporation
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#include <linux/bitops.h>
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#include <linux/dmaengine.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include "internal.h"
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static void dw_dma_initialize_chan(struct dw_dma_chan *dwc)
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{
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struct dw_dma *dw = to_dw_dma(dwc->chan.device);
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u32 cfghi = is_slave_direction(dwc->direction) ? 0 : DWC_CFGH_FIFO_MODE;
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u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
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bool hs_polarity = dwc->dws.hs_polarity;
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cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
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cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);
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cfghi |= DWC_CFGH_PROTCTL(dw->pdata->protctl);
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/* Set polarity of handshake interface */
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cfglo |= hs_polarity ? DWC_CFGL_HS_DST_POL | DWC_CFGL_HS_SRC_POL : 0;
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channel_writel(dwc, CFG_LO, cfglo);
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channel_writel(dwc, CFG_HI, cfghi);
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}
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static void dw_dma_suspend_chan(struct dw_dma_chan *dwc, bool drain)
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{
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u32 cfglo = channel_readl(dwc, CFG_LO);
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channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
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}
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static void dw_dma_resume_chan(struct dw_dma_chan *dwc, bool drain)
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{
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u32 cfglo = channel_readl(dwc, CFG_LO);
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channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
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}
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static u32 dw_dma_bytes2block(struct dw_dma_chan *dwc,
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size_t bytes, unsigned int width, size_t *len)
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{
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u32 block;
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if ((bytes >> width) > dwc->block_size) {
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block = dwc->block_size;
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*len = dwc->block_size << width;
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} else {
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block = bytes >> width;
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*len = bytes;
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}
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return block;
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}
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static size_t dw_dma_block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
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{
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return DWC_CTLH_BLOCK_TS(block) << width;
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}
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static inline u8 dw_dma_encode_maxburst(u32 maxburst)
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{
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/*
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* Fix burst size according to dw_dmac. We need to convert them as:
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* 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
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*/
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return maxburst > 1 ? fls(maxburst) - 2 : 0;
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}
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static u32 dw_dma_prepare_ctllo(struct dw_dma_chan *dwc)
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{
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struct dma_slave_config *sconfig = &dwc->dma_sconfig;
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u8 smsize = 0, dmsize = 0;
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u8 sms, dms;
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if (dwc->direction == DMA_MEM_TO_DEV) {
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sms = dwc->dws.m_master;
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dms = dwc->dws.p_master;
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dmsize = dw_dma_encode_maxburst(sconfig->dst_maxburst);
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} else if (dwc->direction == DMA_DEV_TO_MEM) {
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sms = dwc->dws.p_master;
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dms = dwc->dws.m_master;
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smsize = dw_dma_encode_maxburst(sconfig->src_maxburst);
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} else /* DMA_MEM_TO_MEM */ {
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sms = dwc->dws.m_master;
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dms = dwc->dws.m_master;
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}
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return DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN |
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DWC_CTLL_DST_MSIZE(dmsize) | DWC_CTLL_SRC_MSIZE(smsize) |
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DWC_CTLL_DMS(dms) | DWC_CTLL_SMS(sms);
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}
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static void dw_dma_set_device_name(struct dw_dma *dw, int id)
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{
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snprintf(dw->name, sizeof(dw->name), "dw:dmac%d", id);
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}
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static void dw_dma_disable(struct dw_dma *dw)
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{
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do_dw_dma_off(dw);
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}
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static void dw_dma_enable(struct dw_dma *dw)
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{
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do_dw_dma_on(dw);
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}
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int dw_dma_probe(struct dw_dma_chip *chip)
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{
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struct dw_dma *dw;
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dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
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if (!dw)
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return -ENOMEM;
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/* Channel operations */
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dw->initialize_chan = dw_dma_initialize_chan;
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dw->suspend_chan = dw_dma_suspend_chan;
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dw->resume_chan = dw_dma_resume_chan;
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dw->prepare_ctllo = dw_dma_prepare_ctllo;
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dw->bytes2block = dw_dma_bytes2block;
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dw->block2bytes = dw_dma_block2bytes;
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/* Device operations */
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dw->set_device_name = dw_dma_set_device_name;
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dw->disable = dw_dma_disable;
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dw->enable = dw_dma_enable;
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chip->dw = dw;
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return do_dma_probe(chip);
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}
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EXPORT_SYMBOL_GPL(dw_dma_probe);
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int dw_dma_remove(struct dw_dma_chip *chip)
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{
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return do_dma_remove(chip);
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}
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EXPORT_SYMBOL_GPL(dw_dma_remove);
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