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![Sam Van Den Berge](/assets/img/avatar_default.png)
This patch updates the s3c24xx dma driver to be able to pass a dma_slave_map array via the platform data. This is needed to be able to use the new, simpler dmaengine API [1]. I used the virtual DMA channels as a parameter for the dma_filter function. By doing that, I could reuse the existing filter function in drivers/dma/s3c24xx-dma.c. I have tested this on my mini2440 board with the audio driver. According to my observations, dma_request_slave_channel in the function dmaengine_pcm_new in the file sound/soc/soc-generic-dmaengine-pcm.c now returns a valid DMA channel whereas before no DMA channel was returned at that point. Entries for DMACH_XD0, DMACH_XD1 and DMACH_TIMER are missing because I don't realy know which driver to use for these. [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-December/393635.html Signed-off-by: Sam Van Den Berge <sam.van.den.berge@telenet.be> Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
52 lines
1.5 KiB
C
52 lines
1.5 KiB
C
/*
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* S3C24XX DMA handling
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*
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* Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*/
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/* Helper to encode the source selection constraints for early s3c socs. */
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#define S3C24XX_DMA_CHANREQ(src, chan) ((BIT(3) | src) << chan * 4)
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enum s3c24xx_dma_bus {
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S3C24XX_DMA_APB,
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S3C24XX_DMA_AHB,
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};
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/**
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* @bus: on which bus does the peripheral reside - AHB or APB.
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* @handshake: is a handshake with the peripheral necessary
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* @chansel: channel selection information, depending on variant; reqsel for
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* s3c2443 and later and channel-selection map for earlier SoCs
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* see CHANSEL doc in s3c2443-dma.c
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*/
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struct s3c24xx_dma_channel {
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enum s3c24xx_dma_bus bus;
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bool handshake;
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u16 chansel;
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};
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struct dma_slave_map;
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/**
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* struct s3c24xx_dma_platdata - platform specific settings
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* @num_phy_channels: number of physical channels
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* @channels: array of virtual channel descriptions
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* @num_channels: number of virtual channels
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* @slave_map: dma slave map matching table
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* @slavecnt: number of elements in slave_map
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*/
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struct s3c24xx_dma_platdata {
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int num_phy_channels;
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struct s3c24xx_dma_channel *channels;
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int num_channels;
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const struct dma_slave_map *slave_map;
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int slavecnt;
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};
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struct dma_chan;
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bool s3c24xx_dma_filter(struct dma_chan *chan, void *param);
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