69f7345c95
Add special function that executes a specially crafted circular DMA descriptor. The function doesn't wait for the descriptor to finish the transfer, since the descritor never finishes. This is useful when operating a SmartLCD through the LCDIF interface, as the LCDIF does not give us any means to have continuous refresh of the SmartLCD. Instead, the RUN bit in the LCDIF CTRL register must be triggered manually. This can be worked around by starting an DMA transfer which continuously sets the RUN bit. This function allows starting exactly such transfer. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Anatolij Gustschin <agust@denx.de> Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Stefano Babic <sbabic@denx.de>
167 lines
4.3 KiB
C
167 lines
4.3 KiB
C
/*
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* Freescale i.MX28 APBH DMA
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*
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* Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
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* on behalf of DENX Software Engineering GmbH
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*
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* Based on code from LTIB:
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* Copyright 2008-2010 Freescale Semiconductor, Inc. All Rights Reserved.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#ifndef __DMA_H__
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#define __DMA_H__
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#include <linux/list.h>
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#include <linux/compiler.h>
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#ifndef CONFIG_ARCH_DMA_PIO_WORDS
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#define DMA_PIO_WORDS 15
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#else
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#define DMA_PIO_WORDS CONFIG_ARCH_DMA_PIO_WORDS
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#endif
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#define MXS_DMA_ALIGNMENT 32
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/*
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* MXS DMA channels
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*/
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#if defined(CONFIG_MX23)
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enum {
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MXS_DMA_CHANNEL_AHB_APBH_LCDIF = 0,
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MXS_DMA_CHANNEL_AHB_APBH_SSP0,
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MXS_DMA_CHANNEL_AHB_APBH_SSP1,
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MXS_DMA_CHANNEL_AHB_APBH_RESERVED0,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI0,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI1,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI2,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI3,
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MXS_MAX_DMA_CHANNELS,
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};
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#elif defined(CONFIG_MX28)
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enum {
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MXS_DMA_CHANNEL_AHB_APBH_SSP0 = 0,
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MXS_DMA_CHANNEL_AHB_APBH_SSP1,
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MXS_DMA_CHANNEL_AHB_APBH_SSP2,
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MXS_DMA_CHANNEL_AHB_APBH_SSP3,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI0,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI1,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI2,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI3,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI4,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI5,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI6,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI7,
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MXS_DMA_CHANNEL_AHB_APBH_HSADC,
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MXS_DMA_CHANNEL_AHB_APBH_LCDIF,
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MXS_DMA_CHANNEL_AHB_APBH_RESERVED0,
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MXS_DMA_CHANNEL_AHB_APBH_RESERVED1,
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MXS_MAX_DMA_CHANNELS,
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};
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#elif defined(CONFIG_MX6)
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enum {
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MXS_DMA_CHANNEL_AHB_APBH_GPMI0 = 0,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI1,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI2,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI3,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI4,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI5,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI6,
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MXS_DMA_CHANNEL_AHB_APBH_GPMI7,
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MXS_MAX_DMA_CHANNELS,
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};
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#endif
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/*
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* MXS DMA hardware command.
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*
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* This structure describes the in-memory layout of an entire DMA command,
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* including space for the maximum number of PIO accesses. See the appropriate
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* reference manual for a detailed description of what these fields mean to the
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* DMA hardware.
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*/
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#define MXS_DMA_DESC_COMMAND_MASK 0x3
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#define MXS_DMA_DESC_COMMAND_OFFSET 0
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#define MXS_DMA_DESC_COMMAND_NO_DMAXFER 0x0
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#define MXS_DMA_DESC_COMMAND_DMA_WRITE 0x1
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#define MXS_DMA_DESC_COMMAND_DMA_READ 0x2
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#define MXS_DMA_DESC_COMMAND_DMA_SENSE 0x3
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#define MXS_DMA_DESC_CHAIN (1 << 2)
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#define MXS_DMA_DESC_IRQ (1 << 3)
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#define MXS_DMA_DESC_NAND_LOCK (1 << 4)
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#define MXS_DMA_DESC_NAND_WAIT_4_READY (1 << 5)
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#define MXS_DMA_DESC_DEC_SEM (1 << 6)
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#define MXS_DMA_DESC_WAIT4END (1 << 7)
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#define MXS_DMA_DESC_HALT_ON_TERMINATE (1 << 8)
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#define MXS_DMA_DESC_TERMINATE_FLUSH (1 << 9)
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#define MXS_DMA_DESC_PIO_WORDS_MASK (0xf << 12)
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#define MXS_DMA_DESC_PIO_WORDS_OFFSET 12
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#define MXS_DMA_DESC_BYTES_MASK (0xffff << 16)
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#define MXS_DMA_DESC_BYTES_OFFSET 16
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struct mxs_dma_cmd {
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unsigned long next;
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unsigned long data;
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union {
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dma_addr_t address;
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unsigned long alternate;
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};
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unsigned long pio_words[DMA_PIO_WORDS];
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};
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/*
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* MXS DMA command descriptor.
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*
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* This structure incorporates an MXS DMA hardware command structure, along
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* with metadata.
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*/
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#define MXS_DMA_DESC_FIRST (1 << 0)
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#define MXS_DMA_DESC_LAST (1 << 1)
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#define MXS_DMA_DESC_READY (1 << 31)
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struct mxs_dma_desc {
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struct mxs_dma_cmd cmd;
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unsigned int flags;
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dma_addr_t address;
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void *buffer;
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struct list_head node;
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} __aligned(MXS_DMA_ALIGNMENT);
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/**
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* MXS DMA channel
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*
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* This structure represents a single DMA channel. The MXS platform code
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* maintains an array of these structures to represent every DMA channel in the
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* system (see mxs_dma_channels).
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*/
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#define MXS_DMA_FLAGS_IDLE 0
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#define MXS_DMA_FLAGS_BUSY (1 << 0)
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#define MXS_DMA_FLAGS_FREE 0
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#define MXS_DMA_FLAGS_ALLOCATED (1 << 16)
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#define MXS_DMA_FLAGS_VALID (1 << 31)
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struct mxs_dma_chan {
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const char *name;
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unsigned long dev;
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struct mxs_dma_device *dma;
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unsigned int flags;
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unsigned int active_num;
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unsigned int pending_num;
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struct list_head active;
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struct list_head done;
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};
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struct mxs_dma_desc *mxs_dma_desc_alloc(void);
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void mxs_dma_desc_free(struct mxs_dma_desc *);
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int mxs_dma_desc_append(int channel, struct mxs_dma_desc *pdesc);
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int mxs_dma_go(int chan);
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void mxs_dma_init(void);
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int mxs_dma_init_channel(int chan);
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int mxs_dma_release(int chan);
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void mxs_dma_circ_start(int chan, struct mxs_dma_desc *pdesc);
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#endif /* __DMA_H__ */
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