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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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c8ebae3703
Based on a patch from Linus Walleij. Add dmaengine based support for DMA to the MMCI driver, using the Primecell DMA engine interface. The changes over Linus' driver are: - rename txsize_threshold to dmasize_threshold, as this reflects the purpose more. - use 'mmci_dma_' as the function prefix rather than 'dma_mmci_'. - clean up requesting of dma channels. - don't release a single channel twice when it's shared between tx and rx. - get rid of 'dma_enable' bool - instead check whether the channel is NULL. - detect incomplete DMA at the end of a transfer. Some DMA controllers (eg, PL08x) are unable to be configured for scatter DMA and also listen to all four DMA request signals [BREQ,SREQ,LBREQ,LSREQ] from the MMCI. They can do one or other but not both. As MMCI uses LBREQ/LSREQ for the final burst/words, PL08x does not transfer the last few words. - map and unmap DMA buffers using the DMA engine struct device, not the MMCI struct device - the DMA engine is doing the DMA transfer, not us. - avoid double-unmapping of the DMA buffers on MMCI data errors. - don't check for negative values from the dmaengine tx submission function - Dan says this must never fail. - use new dmaengine helper functions rather than using the ugly function pointers directly. - allow DMA code to be fully optimized away using dma_inprogress() which is defined to constant 0 if DMA engine support is disabled. - request maximum segment size from the DMA engine struct device and set this appropriately. - removed checking of buffer alignment - the DMA engine should deal with its own restrictions on buffer alignment, not the individual DMA engine users. - removed setting DMAREQCTL - this confuses some DMA controllers as it causes LBREQ to be asserted for the last seven transfers, rather than six SREQ and one LSREQ. - removed burst setting - the DMA controller should not burst past the transfer size required to complete the DMA operation. Tested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
61 lines
2.3 KiB
C
61 lines
2.3 KiB
C
/*
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* include/linux/amba/mmci.h
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*/
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#ifndef AMBA_MMCI_H
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#define AMBA_MMCI_H
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#include <linux/mmc/host.h>
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/* Just some dummy forwarding */
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struct dma_chan;
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/**
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* struct mmci_platform_data - platform configuration for the MMCI
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* (also known as PL180) block.
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* @f_max: the maximum operational frequency for this host in this
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* platform configuration. When this is specified it takes precedence
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* over the module parameter for the same frequency.
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* @ocr_mask: available voltages on the 4 pins from the block, this
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* is ignored if a regulator is used, see the MMC_VDD_* masks in
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* mmc/host.h
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* @vdd_handler: a callback function to translate a MMC_VDD_*
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* mask into a value to be binary (or set some other custom bits
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* in MMCIPWR) or:ed and written into the MMCIPWR register of the
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* block. May also control external power based on the power_mode.
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* @status: if no GPIO read function was given to the block in
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* gpio_wp (below) this function will be called to determine
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* whether a card is present in the MMC slot or not
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* @gpio_wp: read this GPIO pin to see if the card is write protected
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* @gpio_cd: read this GPIO pin to detect card insertion
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* @cd_invert: true if the gpio_cd pin value is active low
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* @capabilities: the capabilities of the block as implemented in
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* this platform, signify anything MMC_CAP_* from mmc/host.h
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* @dma_filter: function used to select an apropriate RX and TX
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* DMA channel to be used for DMA, if and only if you're deploying the
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* generic DMA engine
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* @dma_rx_param: parameter passed to the DMA allocation
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* filter in order to select an apropriate RX channel. If
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* there is a bidirectional RX+TX channel, then just specify
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* this and leave dma_tx_param set to NULL
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* @dma_tx_param: parameter passed to the DMA allocation
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* filter in order to select an apropriate TX channel. If this
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* is NULL the driver will attempt to use the RX channel as a
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* bidirectional channel
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*/
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struct mmci_platform_data {
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unsigned int f_max;
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unsigned int ocr_mask;
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u32 (*vdd_handler)(struct device *, unsigned int vdd,
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unsigned char power_mode);
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unsigned int (*status)(struct device *);
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int gpio_wp;
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int gpio_cd;
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bool cd_invert;
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unsigned long capabilities;
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bool (*dma_filter)(struct dma_chan *chan, void *filter_param);
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void *dma_rx_param;
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void *dma_tx_param;
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};
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#endif
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