dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller (dc78baa2) · Commits · 戴 / test

arch/arm/mach-at91/include/mach/at_hdmac.h

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		/*
		* Header file for the Atmel AHB DMA Controller driver
		*
		* Copyright (C) 2008 Atmel Corporation
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*/
		#ifndef AT_HDMAC_H
		#define AT_HDMAC_H

		#include <linux/dmaengine.h>

		/**
		* struct at_dma_platform_data - Controller configuration parameters
		* @nr_channels: Number of channels supported by hardware (max 8)
		* @cap_mask: dma_capability flags supported by the platform
		*/
		struct at_dma_platform_data {
		unsigned int nr_channels;
		dma_cap_mask_t cap_mask;
		};

		#endif /* AT_HDMAC_H */

drivers/dma/Kconfig

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		@@ -46,6 +46,14 @@ config DW_DMAC
		Support the Synopsys DesignWare AHB DMA controller. This
		can be integrated in chips such as the Atmel AT32ap7000.

		config AT_HDMAC
		tristate "Atmel AHB DMA support"
		depends on ARCH_AT91SAM9RL
		select DMA_ENGINE
		help
		Support the Atmel AHB DMA controller. This can be integrated in
		chips such as the Atmel AT91SAM9RL.

		config FSL_DMA
		tristate "Freescale Elo and Elo Plus DMA support"
		depends on FSL_SOC

drivers/dma/Makefile

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		@@ -7,4 +7,5 @@ obj-$(CONFIG_INTEL_IOP_ADMA) += iop-adma.o
		obj-$(CONFIG_FSL_DMA) += fsldma.o
		obj-$(CONFIG_MV_XOR) += mv_xor.o
		obj-$(CONFIG_DW_DMAC) += dw_dmac.o
		obj-$(CONFIG_AT_HDMAC) += at_hdmac.o
		obj-$(CONFIG_MX3_IPU) += ipu/

drivers/dma/at_hdmac.c

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drivers/dma/at_hdmac_regs.h

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		/*
		* Header file for the Atmel AHB DMA Controller driver
		*
		* Copyright (C) 2008 Atmel Corporation
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*/
		#ifndef AT_HDMAC_REGS_H
		#define AT_HDMAC_REGS_H

		#include <mach/at_hdmac.h>

		#define AT_DMA_MAX_NR_CHANNELS 8


		#define AT_DMA_GCFG 0x00 /* Global Configuration Register */
		#define AT_DMA_IF_BIGEND(i) (0x1 << (i)) /* AHB-Lite Interface i in Big-endian mode */
		#define AT_DMA_ARB_CFG (0x1 << 4) /* Arbiter mode. */
		#define AT_DMA_ARB_CFG_FIXED (0x0 << 4)
		#define AT_DMA_ARB_CFG_ROUND_ROBIN (0x1 << 4)

		#define AT_DMA_EN 0x04 /* Controller Enable Register */
		#define AT_DMA_ENABLE (0x1 << 0)

		#define AT_DMA_SREQ 0x08 /* Software Single Request Register */
		#define AT_DMA_SSREQ(x) (0x1 << ((x) << 1)) /* Request a source single transfer on channel x */
		#define AT_DMA_DSREQ(x) (0x1 << (1 + ((x) << 1))) /* Request a destination single transfer on channel x */

		#define AT_DMA_CREQ 0x0C /* Software Chunk Transfer Request Register */
		#define AT_DMA_SCREQ(x) (0x1 << ((x) << 1)) /* Request a source chunk transfer on channel x */
		#define AT_DMA_DCREQ(x) (0x1 << (1 + ((x) << 1))) /* Request a destination chunk transfer on channel x */

		#define AT_DMA_LAST 0x10 /* Software Last Transfer Flag Register */
		#define AT_DMA_SLAST(x) (0x1 << ((x) << 1)) /* This src rq is last tx of buffer on channel x */
		#define AT_DMA_DLAST(x) (0x1 << (1 + ((x) << 1))) /* This dst rq is last tx of buffer on channel x */

		#define AT_DMA_SYNC 0x14 /* Request Synchronization Register */
		#define AT_DMA_SYR(h) (0x1 << (h)) /* Synchronize handshake line h */

		/* Error, Chained Buffer transfer completed and Buffer transfer completed Interrupt registers */
		#define AT_DMA_EBCIER 0x18 /* Enable register */
		#define AT_DMA_EBCIDR 0x1C /* Disable register */
		#define AT_DMA_EBCIMR 0x20 /* Mask Register */
		#define AT_DMA_EBCISR 0x24 /* Status Register */
		#define AT_DMA_CBTC_OFFSET 8
		#define AT_DMA_ERR_OFFSET 16
		#define AT_DMA_BTC(x) (0x1 << (x))
		#define AT_DMA_CBTC(x) (0x1 << (AT_DMA_CBTC_OFFSET + (x)))
		#define AT_DMA_ERR(x) (0x1 << (AT_DMA_ERR_OFFSET + (x)))

		#define AT_DMA_CHER 0x28 /* Channel Handler Enable Register */
		#define AT_DMA_ENA(x) (0x1 << (x))
		#define AT_DMA_SUSP(x) (0x1 << ( 8 + (x)))
		#define AT_DMA_KEEP(x) (0x1 << (24 + (x)))

		#define AT_DMA_CHDR 0x2C /* Channel Handler Disable Register */
		#define AT_DMA_DIS(x) (0x1 << (x))
		#define AT_DMA_RES(x) (0x1 << ( 8 + (x)))

		#define AT_DMA_CHSR 0x30 /* Channel Handler Status Register */
		#define AT_DMA_EMPT(x) (0x1 << (16 + (x)))
		#define AT_DMA_STAL(x) (0x1 << (24 + (x)))


		#define AT_DMA_CH_REGS_BASE 0x3C /* Channel registers base address */
		#define ch_regs(x) (AT_DMA_CH_REGS_BASE + (x) * 0x28) /* Channel x base addr */

		/* Hardware register offset for each channel */
		#define ATC_SADDR_OFFSET 0x00 /* Source Address Register */
		#define ATC_DADDR_OFFSET 0x04 /* Destination Address Register */
		#define ATC_DSCR_OFFSET 0x08 /* Descriptor Address Register */
		#define ATC_CTRLA_OFFSET 0x0C /* Control A Register */
		#define ATC_CTRLB_OFFSET 0x10 /* Control B Register */
		#define ATC_CFG_OFFSET 0x14 /* Configuration Register */
		#define ATC_SPIP_OFFSET 0x18 /* Src PIP Configuration Register */
		#define ATC_DPIP_OFFSET 0x1C /* Dst PIP Configuration Register */


		/* Bitfield definitions */

		/* Bitfields in DSCR */
		#define ATC_DSCR_IF(i) (0x3 & (i)) /* Dsc feched via AHB-Lite Interface i */

		/* Bitfields in CTRLA */
		#define ATC_BTSIZE_MAX 0xFFFFUL /* Maximum Buffer Transfer Size */
		#define ATC_BTSIZE(x) (ATC_BTSIZE_MAX & (x)) /* Buffer Transfer Size */
		#define ATC_SCSIZE_MASK (0x7 << 16) /* Source Chunk Transfer Size */
		#define ATC_SCSIZE_1 (0x0 << 16)
		#define ATC_SCSIZE_4 (0x1 << 16)
		#define ATC_SCSIZE_8 (0x2 << 16)
		#define ATC_SCSIZE_16 (0x3 << 16)
		#define ATC_SCSIZE_32 (0x4 << 16)
		#define ATC_SCSIZE_64 (0x5 << 16)
		#define ATC_SCSIZE_128 (0x6 << 16)
		#define ATC_SCSIZE_256 (0x7 << 16)
		#define ATC_DCSIZE_MASK (0x7 << 20) /* Destination Chunk Transfer Size */
		#define ATC_DCSIZE_1 (0x0 << 20)
		#define ATC_DCSIZE_4 (0x1 << 20)
		#define ATC_DCSIZE_8 (0x2 << 20)
		#define ATC_DCSIZE_16 (0x3 << 20)
		#define ATC_DCSIZE_32 (0x4 << 20)
		#define ATC_DCSIZE_64 (0x5 << 20)
		#define ATC_DCSIZE_128 (0x6 << 20)
		#define ATC_DCSIZE_256 (0x7 << 20)
		#define ATC_SRC_WIDTH_MASK (0x3 << 24) /* Source Single Transfer Size */
		#define ATC_SRC_WIDTH_BYTE (0x0 << 24)
		#define ATC_SRC_WIDTH_HALFWORD (0x1 << 24)
		#define ATC_SRC_WIDTH_WORD (0x2 << 24)
		#define ATC_DST_WIDTH_MASK (0x3 << 28) /* Destination Single Transfer Size */
		#define ATC_DST_WIDTH_BYTE (0x0 << 28)
		#define ATC_DST_WIDTH_HALFWORD (0x1 << 28)
		#define ATC_DST_WIDTH_WORD (0x2 << 28)
		#define ATC_DONE (0x1 << 31) /* Tx Done (only written back in descriptor) */

		/* Bitfields in CTRLB */
		#define ATC_SIF(i) (0x3 & (i)) /* Src tx done via AHB-Lite Interface i */
		#define ATC_DIF(i) ((0x3 & (i)) << 4) /* Dst tx done via AHB-Lite Interface i */
		#define ATC_SRC_PIP (0x1 << 8) /* Source Picture-in-Picture enabled */
		#define ATC_DST_PIP (0x1 << 12) /* Destination Picture-in-Picture enabled */
		#define ATC_SRC_DSCR_DIS (0x1 << 16) /* Src Descriptor fetch disable */
		#define ATC_DST_DSCR_DIS (0x1 << 20) /* Dst Descriptor fetch disable */
		#define ATC_FC_MASK (0x7 << 21) /* Choose Flow Controller */
		#define ATC_FC_MEM2MEM (0x0 << 21) /* Mem-to-Mem (DMA) */
		#define ATC_FC_MEM2PER (0x1 << 21) /* Mem-to-Periph (DMA) */
		#define ATC_FC_PER2MEM (0x2 << 21) /* Periph-to-Mem (DMA) */
		#define ATC_FC_PER2PER (0x3 << 21) /* Periph-to-Periph (DMA) */
		#define ATC_FC_PER2MEM_PER (0x4 << 21) /* Periph-to-Mem (Peripheral) */
		#define ATC_FC_MEM2PER_PER (0x5 << 21) /* Mem-to-Periph (Peripheral) */
		#define ATC_FC_PER2PER_PER (0x6 << 21) /* Periph-to-Periph (Src Peripheral) */
		#define ATC_SRC_ADDR_MODE_MASK (0x3 << 24)
		#define ATC_SRC_ADDR_MODE_INCR (0x0 << 24) /* Incrementing Mode */
		#define ATC_SRC_ADDR_MODE_DECR (0x1 << 24) /* Decrementing Mode */
		#define ATC_SRC_ADDR_MODE_FIXED (0x2 << 24) /* Fixed Mode */
		#define ATC_DST_ADDR_MODE_MASK (0x3 << 28)
		#define ATC_DST_ADDR_MODE_INCR (0x0 << 28) /* Incrementing Mode */
		#define ATC_DST_ADDR_MODE_DECR (0x1 << 28) /* Decrementing Mode */
		#define ATC_DST_ADDR_MODE_FIXED (0x2 << 28) /* Fixed Mode */
		#define ATC_IEN (0x1 << 30) /* BTC interrupt enable (active low) */
		#define ATC_AUTO (0x1 << 31) /* Auto multiple buffer tx enable */

		/* Bitfields in CFG */
		#define ATC_SRC_PER(h) (0xFU & (h)) /* Channel src rq associated with periph handshaking ifc h */
		#define ATC_DST_PER(h) ((0xFU & (h)) << 4) /* Channel dst rq associated with periph handshaking ifc h */
		#define ATC_SRC_REP (0x1 << 8) /* Source Replay Mod */
		#define ATC_SRC_H2SEL (0x1 << 9) /* Source Handshaking Mod */
		#define ATC_SRC_H2SEL_SW (0x0 << 9)
		#define ATC_SRC_H2SEL_HW (0x1 << 9)
		#define ATC_DST_REP (0x1 << 12) /* Destination Replay Mod */
		#define ATC_DST_H2SEL (0x1 << 13) /* Destination Handshaking Mod */
		#define ATC_DST_H2SEL_SW (0x0 << 13)
		#define ATC_DST_H2SEL_HW (0x1 << 13)
		#define ATC_SOD (0x1 << 16) /* Stop On Done */
		#define ATC_LOCK_IF (0x1 << 20) /* Interface Lock */
		#define ATC_LOCK_B (0x1 << 21) /* AHB Bus Lock */
		#define ATC_LOCK_IF_L (0x1 << 22) /* Master Interface Arbiter Lock */
		#define ATC_LOCK_IF_L_CHUNK (0x0 << 22)
		#define ATC_LOCK_IF_L_BUFFER (0x1 << 22)
		#define ATC_AHB_PROT_MASK (0x7 << 24) /* AHB Protection */
		#define ATC_FIFOCFG_MASK (0x3 << 28) /* FIFO Request Configuration */
		#define ATC_FIFOCFG_LARGESTBURST (0x0 << 28)
		#define ATC_FIFOCFG_HALFFIFO (0x1 << 28)
		#define ATC_FIFOCFG_ENOUGHSPACE (0x2 << 28)

		/* Bitfields in SPIP */
		#define ATC_SPIP_HOLE(x) (0xFFFFU & (x))
		#define ATC_SPIP_BOUNDARY(x) ((0x3FF & (x)) << 16)

		/* Bitfields in DPIP */
		#define ATC_DPIP_HOLE(x) (0xFFFFU & (x))
		#define ATC_DPIP_BOUNDARY(x) ((0x3FF & (x)) << 16)


		/-- descriptors -----------------------------------------------------/

		/* LLI == Linked List Item; aka DMA buffer descriptor */
		struct at_lli {
		/* values that are not changed by hardware */
		dma_addr_t saddr;
		dma_addr_t daddr;
		/* value that may get written back: */
		u32 ctrla;
		/* more values that are not changed by hardware */
		u32 ctrlb;
		dma_addr_t dscr; /* chain to next lli */
		};

		/**
		* struct at_desc - software descriptor
		* @at_lli: hardware lli structure
		* @txd: support for the async_tx api
		* @desc_node: node on the channed descriptors list
		* @len: total transaction bytecount
		*/
		struct at_desc {
		/* FIRST values the hardware uses */
		struct at_lli lli;

		/* THEN values for driver housekeeping */
		struct dma_async_tx_descriptor txd;
		struct list_head desc_node;
		size_t len;
		};

		static inline struct at_desc *
		txd_to_at_desc(struct dma_async_tx_descriptor *txd)
		{
		return container_of(txd, struct at_desc, txd);
		}


		/-- Channels --------------------------------------------------------/

		/**
		* struct at_dma_chan - internal representation of an Atmel HDMAC channel
		* @chan_common: common dmaengine channel object members
		* @device: parent device
		* @ch_regs: memory mapped register base
		* @mask: channel index in a mask
		* @error_status: transmit error status information from irq handler
		* to tasklet (use atomic operations)
		* @tasklet: bottom half to finish transaction work
		* @lock: serializes enqueue/dequeue operations to descriptors lists
		* @completed_cookie: identifier for the most recently completed operation
		* @active_list: list of descriptors dmaengine is being running on
		* @queue: list of descriptors ready to be submitted to engine
		* @free_list: list of descriptors usable by the channel
		* @descs_allocated: records the actual size of the descriptor pool
		*/
		struct at_dma_chan {
		struct dma_chan chan_common;
		struct at_dma *device;
		void __iomem *ch_regs;
		u8 mask;
		unsigned long error_status;
		struct tasklet_struct tasklet;

		spinlock_t lock;

		/* these other elements are all protected by lock */
		dma_cookie_t completed_cookie;
		struct list_head active_list;
		struct list_head queue;
		struct list_head free_list;
		unsigned int descs_allocated;
		};

		#define channel_readl(atchan, name) \
		__raw_readl((atchan)->ch_regs + ATC_##name##_OFFSET)

		#define channel_writel(atchan, name, val) \
		__raw_writel((val), (atchan)->ch_regs + ATC_##name##_OFFSET)

		static inline struct at_dma_chan to_at_dma_chan(struct dma_chan dchan)
		{
		return container_of(dchan, struct at_dma_chan, chan_common);
		}


		/-- Controller ------------------------------------------------------/

		/**
		* struct at_dma - internal representation of an Atmel HDMA Controller
		* @chan_common: common dmaengine dma_device object members
		* @ch_regs: memory mapped register base
		* @clk: dma controller clock
		* @all_chan_mask: all channels availlable in a mask
		* @dma_desc_pool: base of DMA descriptor region (DMA address)
		* @chan: channels table to store at_dma_chan structures
		*/
		struct at_dma {
		struct dma_device dma_common;
		void __iomem *regs;
		struct clk *clk;

		u8 all_chan_mask;

		struct dma_pool *dma_desc_pool;
		/* AT THE END channels table */
		struct at_dma_chan chan[0];
		};

		#define dma_readl(atdma, name) \
		__raw_readl((atdma)->regs + AT_DMA_##name)
		#define dma_writel(atdma, name, val) \
		__raw_writel((val), (atdma)->regs + AT_DMA_##name)

		static inline struct at_dma to_at_dma(struct dma_device ddev)
		{
		return container_of(ddev, struct at_dma, dma_common);
		}


		/-- Helper functions ------------------------------------------------/

		static struct device chan2dev(struct dma_chan chan)
		{
		return &chan->dev->device;
		}
		static struct device chan2parent(struct dma_chan chan)
		{
		return chan->dev->device.parent;
		}

		#if defined(VERBOSE_DEBUG)
		static void vdbg_dump_regs(struct at_dma_chan *atchan)
		{
		struct at_dma *atdma = to_at_dma(atchan->chan_common.device);

		dev_err(chan2dev(&atchan->chan_common),
		" channel %d : imr = 0x%x, chsr = 0x%x\n",
		atchan->chan_common.chan_id,
		dma_readl(atdma, EBCIMR),
		dma_readl(atdma, CHSR));

		dev_err(chan2dev(&atchan->chan_common),
		" channel: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n",
		channel_readl(atchan, SADDR),
		channel_readl(atchan, DADDR),
		channel_readl(atchan, CTRLA),
		channel_readl(atchan, CTRLB),
		channel_readl(atchan, DSCR));
		}
		#else
		static void vdbg_dump_regs(struct at_dma_chan *atchan) {}
		#endif

		static void atc_dump_lli(struct at_dma_chan atchan, struct at_lli lli)
		{
		dev_printk(KERN_CRIT, chan2dev(&atchan->chan_common),
		" desc: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n",
		lli->saddr, lli->daddr,
		lli->ctrla, lli->ctrlb, lli->dscr);
		}


		static void atc_setup_irq(struct at_dma_chan *atchan, int on)
		{
		struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
		u32 ebci;

		/* enable interrupts on buffer chain completion & error */
		ebci = AT_DMA_CBTC(atchan->chan_common.chan_id)
		\| AT_DMA_ERR(atchan->chan_common.chan_id);
		if (on)
		dma_writel(atdma, EBCIER, ebci);
		else
		dma_writel(atdma, EBCIDR, ebci);
		}

		static inline void atc_enable_irq(struct at_dma_chan *atchan)
		{
		atc_setup_irq(atchan, 1);
		}

		static inline void atc_disable_irq(struct at_dma_chan *atchan)
		{
		atc_setup_irq(atchan, 0);
		}


		/**
		* atc_chan_is_enabled - test if given channel is enabled
		* @atchan: channel we want to test status
		*/
		static inline int atc_chan_is_enabled(struct at_dma_chan *atchan)
		{
		struct at_dma *atdma = to_at_dma(atchan->chan_common.device);

		return !!(dma_readl(atdma, CHSR) & atchan->mask);
		}


		/**
		* set_desc_eol - set end-of-link to descriptor so it will end transfer
		* @desc: descriptor, signle or at the end of a chain, to end chain on
		*/
		static void set_desc_eol(struct at_desc *desc)
		{
		desc->lli.ctrlb \|= ATC_SRC_DSCR_DIS \| ATC_DST_DSCR_DIS;
		desc->lli.dscr = 0;
		}

		#endif /* AT_HDMAC_REGS_H */

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