1010 lines
26 KiB
C
1010 lines
26 KiB
C
![]() |
/*
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* Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems)
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*
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* Copyright (C) 2008 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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*
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* This supports the Atmel AHB DMA Controller,
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*
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* The driver has currently been tested with the Atmel AT91SAM9RL
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* and AT91SAM9G45 series.
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*/
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#include <linux/clk.h>
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#include <linux/dmaengine.h>
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#include <linux/dma-mapping.h>
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#include <linux/dmapool.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include "at_hdmac_regs.h"
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/*
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* Glossary
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* --------
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*
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* at_hdmac : Name of the ATmel AHB DMA Controller
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* at_dma_ / atdma : ATmel DMA controller entity related
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* atc_ / atchan : ATmel DMA Channel entity related
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*/
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#define ATC_DEFAULT_CFG (ATC_FIFOCFG_HALFFIFO)
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#define ATC_DEFAULT_CTRLA (0)
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#define ATC_DEFAULT_CTRLB (ATC_SIF(0) \
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|ATC_DIF(1))
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/*
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* Initial number of descriptors to allocate for each channel. This could
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* be increased during dma usage.
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*/
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static unsigned int init_nr_desc_per_channel = 64;
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module_param(init_nr_desc_per_channel, uint, 0644);
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MODULE_PARM_DESC(init_nr_desc_per_channel,
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"initial descriptors per channel (default: 64)");
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/* prototypes */
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static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx);
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/*----------------------------------------------------------------------*/
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static struct at_desc *atc_first_active(struct at_dma_chan *atchan)
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{
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return list_first_entry(&atchan->active_list,
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struct at_desc, desc_node);
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}
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static struct at_desc *atc_first_queued(struct at_dma_chan *atchan)
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{
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return list_first_entry(&atchan->queue,
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struct at_desc, desc_node);
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}
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/**
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* atc_alloc_descriptor - allocate and return an initilized descriptor
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* @chan: the channel to allocate descriptors for
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* @gfp_flags: GFP allocation flags
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*
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* Note: The ack-bit is positioned in the descriptor flag at creation time
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* to make initial allocation more convenient. This bit will be cleared
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* and control will be given to client at usage time (during
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* preparation functions).
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*/
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static struct at_desc *atc_alloc_descriptor(struct dma_chan *chan,
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gfp_t gfp_flags)
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{
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struct at_desc *desc = NULL;
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struct at_dma *atdma = to_at_dma(chan->device);
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dma_addr_t phys;
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desc = dma_pool_alloc(atdma->dma_desc_pool, gfp_flags, &phys);
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if (desc) {
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memset(desc, 0, sizeof(struct at_desc));
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dma_async_tx_descriptor_init(&desc->txd, chan);
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/* txd.flags will be overwritten in prep functions */
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desc->txd.flags = DMA_CTRL_ACK;
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desc->txd.tx_submit = atc_tx_submit;
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desc->txd.phys = phys;
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}
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return desc;
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}
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/**
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* atc_desc_get - get a unsused descriptor from free_list
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* @atchan: channel we want a new descriptor for
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*/
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static struct at_desc *atc_desc_get(struct at_dma_chan *atchan)
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{
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struct at_desc *desc, *_desc;
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struct at_desc *ret = NULL;
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unsigned int i = 0;
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LIST_HEAD(tmp_list);
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spin_lock_bh(&atchan->lock);
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list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
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i++;
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if (async_tx_test_ack(&desc->txd)) {
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list_del(&desc->desc_node);
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ret = desc;
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break;
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}
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dev_dbg(chan2dev(&atchan->chan_common),
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"desc %p not ACKed\n", desc);
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}
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spin_unlock_bh(&atchan->lock);
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dev_vdbg(chan2dev(&atchan->chan_common),
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"scanned %u descriptors on freelist\n", i);
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/* no more descriptor available in initial pool: create one more */
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if (!ret) {
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ret = atc_alloc_descriptor(&atchan->chan_common, GFP_ATOMIC);
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if (ret) {
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spin_lock_bh(&atchan->lock);
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atchan->descs_allocated++;
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spin_unlock_bh(&atchan->lock);
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} else {
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dev_err(chan2dev(&atchan->chan_common),
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"not enough descriptors available\n");
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}
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}
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return ret;
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}
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/**
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* atc_desc_put - move a descriptor, including any children, to the free list
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* @atchan: channel we work on
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* @desc: descriptor, at the head of a chain, to move to free list
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*/
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static void atc_desc_put(struct at_dma_chan *atchan, struct at_desc *desc)
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{
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if (desc) {
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struct at_desc *child;
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spin_lock_bh(&atchan->lock);
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list_for_each_entry(child, &desc->txd.tx_list, desc_node)
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dev_vdbg(chan2dev(&atchan->chan_common),
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"moving child desc %p to freelist\n",
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child);
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list_splice_init(&desc->txd.tx_list, &atchan->free_list);
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dev_vdbg(chan2dev(&atchan->chan_common),
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"moving desc %p to freelist\n", desc);
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list_add(&desc->desc_node, &atchan->free_list);
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spin_unlock_bh(&atchan->lock);
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}
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}
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/**
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* atc_assign_cookie - compute and assign new cookie
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* @atchan: channel we work on
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* @desc: descriptor to asign cookie for
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*
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* Called with atchan->lock held and bh disabled
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*/
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static dma_cookie_t
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atc_assign_cookie(struct at_dma_chan *atchan, struct at_desc *desc)
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{
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dma_cookie_t cookie = atchan->chan_common.cookie;
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if (++cookie < 0)
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cookie = 1;
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atchan->chan_common.cookie = cookie;
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desc->txd.cookie = cookie;
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return cookie;
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}
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/**
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* atc_dostart - starts the DMA engine for real
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* @atchan: the channel we want to start
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* @first: first descriptor in the list we want to begin with
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*
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* Called with atchan->lock held and bh disabled
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*/
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static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
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{
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struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
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/* ASSERT: channel is idle */
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if (atc_chan_is_enabled(atchan)) {
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dev_err(chan2dev(&atchan->chan_common),
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"BUG: Attempted to start non-idle channel\n");
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dev_err(chan2dev(&atchan->chan_common),
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" channel: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n",
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channel_readl(atchan, SADDR),
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channel_readl(atchan, DADDR),
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channel_readl(atchan, CTRLA),
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channel_readl(atchan, CTRLB),
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channel_readl(atchan, DSCR));
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/* The tasklet will hopefully advance the queue... */
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return;
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}
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vdbg_dump_regs(atchan);
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/* clear any pending interrupt */
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while (dma_readl(atdma, EBCISR))
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cpu_relax();
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channel_writel(atchan, SADDR, 0);
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channel_writel(atchan, DADDR, 0);
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channel_writel(atchan, CTRLA, 0);
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channel_writel(atchan, CTRLB, 0);
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channel_writel(atchan, DSCR, first->txd.phys);
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dma_writel(atdma, CHER, atchan->mask);
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vdbg_dump_regs(atchan);
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}
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/**
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* atc_chain_complete - finish work for one transaction chain
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* @atchan: channel we work on
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* @desc: descriptor at the head of the chain we want do complete
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*
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* Called with atchan->lock held and bh disabled */
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static void
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atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
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{
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dma_async_tx_callback callback;
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void *param;
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struct dma_async_tx_descriptor *txd = &desc->txd;
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dev_vdbg(chan2dev(&atchan->chan_common),
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"descriptor %u complete\n", txd->cookie);
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atchan->completed_cookie = txd->cookie;
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callback = txd->callback;
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param = txd->callback_param;
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/* move children to free_list */
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list_splice_init(&txd->tx_list, &atchan->free_list);
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/* move myself to free_list */
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list_move(&desc->desc_node, &atchan->free_list);
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/* unmap dma addresses */
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if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
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if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
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dma_unmap_single(chan2parent(&atchan->chan_common),
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desc->lli.daddr,
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desc->len, DMA_FROM_DEVICE);
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else
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dma_unmap_page(chan2parent(&atchan->chan_common),
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desc->lli.daddr,
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desc->len, DMA_FROM_DEVICE);
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}
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if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
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if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
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dma_unmap_single(chan2parent(&atchan->chan_common),
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desc->lli.saddr,
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desc->len, DMA_TO_DEVICE);
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else
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dma_unmap_page(chan2parent(&atchan->chan_common),
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desc->lli.saddr,
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desc->len, DMA_TO_DEVICE);
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}
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/*
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* The API requires that no submissions are done from a
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* callback, so we don't need to drop the lock here
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*/
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if (callback)
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callback(param);
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dma_run_dependencies(txd);
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}
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/**
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* atc_complete_all - finish work for all transactions
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* @atchan: channel to complete transactions for
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*
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* Eventually submit queued descriptors if any
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*
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* Assume channel is idle while calling this function
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* Called with atchan->lock held and bh disabled
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*/
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static void atc_complete_all(struct at_dma_chan *atchan)
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{
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struct at_desc *desc, *_desc;
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LIST_HEAD(list);
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dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
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BUG_ON(atc_chan_is_enabled(atchan));
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/*
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* Submit queued descriptors ASAP, i.e. before we go through
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* the completed ones.
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*/
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if (!list_empty(&atchan->queue))
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atc_dostart(atchan, atc_first_queued(atchan));
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/* empty active_list now it is completed */
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list_splice_init(&atchan->active_list, &list);
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/* empty queue list by moving descriptors (if any) to active_list */
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list_splice_init(&atchan->queue, &atchan->active_list);
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list_for_each_entry_safe(desc, _desc, &list, desc_node)
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atc_chain_complete(atchan, desc);
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}
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/**
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* atc_cleanup_descriptors - cleanup up finished descriptors in active_list
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* @atchan: channel to be cleaned up
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*
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* Called with atchan->lock held and bh disabled
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*/
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static void atc_cleanup_descriptors(struct at_dma_chan *atchan)
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{
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struct at_desc *desc, *_desc;
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struct at_desc *child;
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dev_vdbg(chan2dev(&atchan->chan_common), "cleanup descriptors\n");
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list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
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if (!(desc->lli.ctrla & ATC_DONE))
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/* This one is currently in progress */
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return;
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list_for_each_entry(child, &desc->txd.tx_list, desc_node)
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if (!(child->lli.ctrla & ATC_DONE))
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/* Currently in progress */
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return;
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/*
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* No descriptors so far seem to be in progress, i.e.
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* this chain must be done.
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*/
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atc_chain_complete(atchan, desc);
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}
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}
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/**
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* atc_advance_work - at the end of a transaction, move forward
|
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* @atchan: channel where the transaction ended
|
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*
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* Called with atchan->lock held and bh disabled
|
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|
*/
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static void atc_advance_work(struct at_dma_chan *atchan)
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{
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dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
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if (list_empty(&atchan->active_list) ||
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list_is_singular(&atchan->active_list)) {
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atc_complete_all(atchan);
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} else {
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atc_chain_complete(atchan, atc_first_active(atchan));
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/* advance work */
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atc_dostart(atchan, atc_first_active(atchan));
|
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}
|
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|
}
|
||
|
|
||
|
|
||
|
/**
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* atc_handle_error - handle errors reported by DMA controller
|
||
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* @atchan: channel where error occurs
|
||
|
*
|
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* Called with atchan->lock held and bh disabled
|
||
|
*/
|
||
|
static void atc_handle_error(struct at_dma_chan *atchan)
|
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|
{
|
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struct at_desc *bad_desc;
|
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struct at_desc *child;
|
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|
|
||
|
/*
|
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* The descriptor currently at the head of the active list is
|
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|
* broked. Since we don't have any way to report errors, we'll
|
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|
* just have to scream loudly and try to carry on.
|
||
|
*/
|
||
|
bad_desc = atc_first_active(atchan);
|
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list_del_init(&bad_desc->desc_node);
|
||
|
|
||
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/* As we are stopped, take advantage to push queued descriptors
|
||
|
* in active_list */
|
||
|
list_splice_init(&atchan->queue, atchan->active_list.prev);
|
||
|
|
||
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/* Try to restart the controller */
|
||
|
if (!list_empty(&atchan->active_list))
|
||
|
atc_dostart(atchan, atc_first_active(atchan));
|
||
|
|
||
|
/*
|
||
|
* KERN_CRITICAL may seem harsh, but since this only happens
|
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|
* when someone submits a bad physical address in a
|
||
|
* descriptor, we should consider ourselves lucky that the
|
||
|
* controller flagged an error instead of scribbling over
|
||
|
* random memory locations.
|
||
|
*/
|
||
|
dev_crit(chan2dev(&atchan->chan_common),
|
||
|
"Bad descriptor submitted for DMA!\n");
|
||
|
dev_crit(chan2dev(&atchan->chan_common),
|
||
|
" cookie: %d\n", bad_desc->txd.cookie);
|
||
|
atc_dump_lli(atchan, &bad_desc->lli);
|
||
|
list_for_each_entry(child, &bad_desc->txd.tx_list, desc_node)
|
||
|
atc_dump_lli(atchan, &child->lli);
|
||
|
|
||
|
/* Pretend the descriptor completed successfully */
|
||
|
atc_chain_complete(atchan, bad_desc);
|
||
|
}
|
||
|
|
||
|
|
||
|
/*-- IRQ & Tasklet ---------------------------------------------------*/
|
||
|
|
||
|
static void atc_tasklet(unsigned long data)
|
||
|
{
|
||
|
struct at_dma_chan *atchan = (struct at_dma_chan *)data;
|
||
|
|
||
|
/* Channel cannot be enabled here */
|
||
|
if (atc_chan_is_enabled(atchan)) {
|
||
|
dev_err(chan2dev(&atchan->chan_common),
|
||
|
"BUG: channel enabled in tasklet\n");
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
spin_lock(&atchan->lock);
|
||
|
if (test_and_clear_bit(0, &atchan->error_status))
|
||
|
atc_handle_error(atchan);
|
||
|
else
|
||
|
atc_advance_work(atchan);
|
||
|
|
||
|
spin_unlock(&atchan->lock);
|
||
|
}
|
||
|
|
||
|
static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
|
||
|
{
|
||
|
struct at_dma *atdma = (struct at_dma *)dev_id;
|
||
|
struct at_dma_chan *atchan;
|
||
|
int i;
|
||
|
u32 status, pending, imr;
|
||
|
int ret = IRQ_NONE;
|
||
|
|
||
|
do {
|
||
|
imr = dma_readl(atdma, EBCIMR);
|
||
|
status = dma_readl(atdma, EBCISR);
|
||
|
pending = status & imr;
|
||
|
|
||
|
if (!pending)
|
||
|
break;
|
||
|
|
||
|
dev_vdbg(atdma->dma_common.dev,
|
||
|
"interrupt: status = 0x%08x, 0x%08x, 0x%08x\n",
|
||
|
status, imr, pending);
|
||
|
|
||
|
for (i = 0; i < atdma->dma_common.chancnt; i++) {
|
||
|
atchan = &atdma->chan[i];
|
||
|
if (pending & (AT_DMA_CBTC(i) | AT_DMA_ERR(i))) {
|
||
|
if (pending & AT_DMA_ERR(i)) {
|
||
|
/* Disable channel on AHB error */
|
||
|
dma_writel(atdma, CHDR, atchan->mask);
|
||
|
/* Give information to tasklet */
|
||
|
set_bit(0, &atchan->error_status);
|
||
|
}
|
||
|
tasklet_schedule(&atchan->tasklet);
|
||
|
ret = IRQ_HANDLED;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
} while (pending);
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
|
||
|
/*-- DMA Engine API --------------------------------------------------*/
|
||
|
|
||
|
/**
|
||
|
* atc_tx_submit - set the prepared descriptor(s) to be executed by the engine
|
||
|
* @desc: descriptor at the head of the transaction chain
|
||
|
*
|
||
|
* Queue chain if DMA engine is working already
|
||
|
*
|
||
|
* Cookie increment and adding to active_list or queue must be atomic
|
||
|
*/
|
||
|
static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx)
|
||
|
{
|
||
|
struct at_desc *desc = txd_to_at_desc(tx);
|
||
|
struct at_dma_chan *atchan = to_at_dma_chan(tx->chan);
|
||
|
dma_cookie_t cookie;
|
||
|
|
||
|
spin_lock_bh(&atchan->lock);
|
||
|
cookie = atc_assign_cookie(atchan, desc);
|
||
|
|
||
|
if (list_empty(&atchan->active_list)) {
|
||
|
dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",
|
||
|
desc->txd.cookie);
|
||
|
atc_dostart(atchan, desc);
|
||
|
list_add_tail(&desc->desc_node, &atchan->active_list);
|
||
|
} else {
|
||
|
dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
|
||
|
desc->txd.cookie);
|
||
|
list_add_tail(&desc->desc_node, &atchan->queue);
|
||
|
}
|
||
|
|
||
|
spin_unlock_bh(&atchan->lock);
|
||
|
|
||
|
return cookie;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* atc_prep_dma_memcpy - prepare a memcpy operation
|
||
|
* @chan: the channel to prepare operation on
|
||
|
* @dest: operation virtual destination address
|
||
|
* @src: operation virtual source address
|
||
|
* @len: operation length
|
||
|
* @flags: tx descriptor status flags
|
||
|
*/
|
||
|
static struct dma_async_tx_descriptor *
|
||
|
atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
|
||
|
size_t len, unsigned long flags)
|
||
|
{
|
||
|
struct at_dma_chan *atchan = to_at_dma_chan(chan);
|
||
|
struct at_desc *desc = NULL;
|
||
|
struct at_desc *first = NULL;
|
||
|
struct at_desc *prev = NULL;
|
||
|
size_t xfer_count;
|
||
|
size_t offset;
|
||
|
unsigned int src_width;
|
||
|
unsigned int dst_width;
|
||
|
u32 ctrla;
|
||
|
u32 ctrlb;
|
||
|
|
||
|
dev_vdbg(chan2dev(chan), "prep_dma_memcpy: d0x%x s0x%x l0x%zx f0x%lx\n",
|
||
|
dest, src, len, flags);
|
||
|
|
||
|
if (unlikely(!len)) {
|
||
|
dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
ctrla = ATC_DEFAULT_CTRLA;
|
||
|
ctrlb = ATC_DEFAULT_CTRLB
|
||
|
| ATC_SRC_ADDR_MODE_INCR
|
||
|
| ATC_DST_ADDR_MODE_INCR
|
||
|
| ATC_FC_MEM2MEM;
|
||
|
|
||
|
/*
|
||
|
* We can be a lot more clever here, but this should take care
|
||
|
* of the most common optimization.
|
||
|
*/
|
||
|
if (!((src | dest | len) & 3)) {
|
||
|
ctrla |= ATC_SRC_WIDTH_WORD | ATC_DST_WIDTH_WORD;
|
||
|
src_width = dst_width = 2;
|
||
|
} else if (!((src | dest | len) & 1)) {
|
||
|
ctrla |= ATC_SRC_WIDTH_HALFWORD | ATC_DST_WIDTH_HALFWORD;
|
||
|
src_width = dst_width = 1;
|
||
|
} else {
|
||
|
ctrla |= ATC_SRC_WIDTH_BYTE | ATC_DST_WIDTH_BYTE;
|
||
|
src_width = dst_width = 0;
|
||
|
}
|
||
|
|
||
|
for (offset = 0; offset < len; offset += xfer_count << src_width) {
|
||
|
xfer_count = min_t(size_t, (len - offset) >> src_width,
|
||
|
ATC_BTSIZE_MAX);
|
||
|
|
||
|
desc = atc_desc_get(atchan);
|
||
|
if (!desc)
|
||
|
goto err_desc_get;
|
||
|
|
||
|
desc->lli.saddr = src + offset;
|
||
|
desc->lli.daddr = dest + offset;
|
||
|
desc->lli.ctrla = ctrla | xfer_count;
|
||
|
desc->lli.ctrlb = ctrlb;
|
||
|
|
||
|
desc->txd.cookie = 0;
|
||
|
async_tx_ack(&desc->txd);
|
||
|
|
||
|
if (!first) {
|
||
|
first = desc;
|
||
|
} else {
|
||
|
/* inform the HW lli about chaining */
|
||
|
prev->lli.dscr = desc->txd.phys;
|
||
|
/* insert the link descriptor to the LD ring */
|
||
|
list_add_tail(&desc->desc_node,
|
||
|
&first->txd.tx_list);
|
||
|
}
|
||
|
prev = desc;
|
||
|
}
|
||
|
|
||
|
/* First descriptor of the chain embedds additional information */
|
||
|
first->txd.cookie = -EBUSY;
|
||
|
first->len = len;
|
||
|
|
||
|
/* set end-of-link to the last link descriptor of list*/
|
||
|
set_desc_eol(desc);
|
||
|
|
||
|
desc->txd.flags = flags; /* client is in control of this ack */
|
||
|
|
||
|
return &first->txd;
|
||
|
|
||
|
err_desc_get:
|
||
|
atc_desc_put(atchan, first);
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* atc_is_tx_complete - poll for transaction completion
|
||
|
* @chan: DMA channel
|
||
|
* @cookie: transaction identifier to check status of
|
||
|
* @done: if not %NULL, updated with last completed transaction
|
||
|
* @used: if not %NULL, updated with last used transaction
|
||
|
*
|
||
|
* If @done and @used are passed in, upon return they reflect the driver
|
||
|
* internal state and can be used with dma_async_is_complete() to check
|
||
|
* the status of multiple cookies without re-checking hardware state.
|
||
|
*/
|
||
|
static enum dma_status
|
||
|
atc_is_tx_complete(struct dma_chan *chan,
|
||
|
dma_cookie_t cookie,
|
||
|
dma_cookie_t *done, dma_cookie_t *used)
|
||
|
{
|
||
|
struct at_dma_chan *atchan = to_at_dma_chan(chan);
|
||
|
dma_cookie_t last_used;
|
||
|
dma_cookie_t last_complete;
|
||
|
enum dma_status ret;
|
||
|
|
||
|
dev_vdbg(chan2dev(chan), "is_tx_complete: %d (d%d, u%d)\n",
|
||
|
cookie, done ? *done : 0, used ? *used : 0);
|
||
|
|
||
|
spin_lock_bh(atchan->lock);
|
||
|
|
||
|
last_complete = atchan->completed_cookie;
|
||
|
last_used = chan->cookie;
|
||
|
|
||
|
ret = dma_async_is_complete(cookie, last_complete, last_used);
|
||
|
if (ret != DMA_SUCCESS) {
|
||
|
atc_cleanup_descriptors(atchan);
|
||
|
|
||
|
last_complete = atchan->completed_cookie;
|
||
|
last_used = chan->cookie;
|
||
|
|
||
|
ret = dma_async_is_complete(cookie, last_complete, last_used);
|
||
|
}
|
||
|
|
||
|
spin_unlock_bh(atchan->lock);
|
||
|
|
||
|
if (done)
|
||
|
*done = last_complete;
|
||
|
if (used)
|
||
|
*used = last_used;
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* atc_issue_pending - try to finish work
|
||
|
* @chan: target DMA channel
|
||
|
*/
|
||
|
static void atc_issue_pending(struct dma_chan *chan)
|
||
|
{
|
||
|
struct at_dma_chan *atchan = to_at_dma_chan(chan);
|
||
|
|
||
|
dev_vdbg(chan2dev(chan), "issue_pending\n");
|
||
|
|
||
|
if (!atc_chan_is_enabled(atchan)) {
|
||
|
spin_lock_bh(&atchan->lock);
|
||
|
atc_advance_work(atchan);
|
||
|
spin_unlock_bh(&atchan->lock);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* atc_alloc_chan_resources - allocate resources for DMA channel
|
||
|
* @chan: allocate descriptor resources for this channel
|
||
|
* @client: current client requesting the channel be ready for requests
|
||
|
*
|
||
|
* return - the number of allocated descriptors
|
||
|
*/
|
||
|
static int atc_alloc_chan_resources(struct dma_chan *chan)
|
||
|
{
|
||
|
struct at_dma_chan *atchan = to_at_dma_chan(chan);
|
||
|
struct at_dma *atdma = to_at_dma(chan->device);
|
||
|
struct at_desc *desc;
|
||
|
int i;
|
||
|
LIST_HEAD(tmp_list);
|
||
|
|
||
|
dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
|
||
|
|
||
|
/* ASSERT: channel is idle */
|
||
|
if (atc_chan_is_enabled(atchan)) {
|
||
|
dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
|
||
|
return -EIO;
|
||
|
}
|
||
|
|
||
|
/* have we already been set up? */
|
||
|
if (!list_empty(&atchan->free_list))
|
||
|
return atchan->descs_allocated;
|
||
|
|
||
|
/* Allocate initial pool of descriptors */
|
||
|
for (i = 0; i < init_nr_desc_per_channel; i++) {
|
||
|
desc = atc_alloc_descriptor(chan, GFP_KERNEL);
|
||
|
if (!desc) {
|
||
|
dev_err(atdma->dma_common.dev,
|
||
|
"Only %d initial descriptors\n", i);
|
||
|
break;
|
||
|
}
|
||
|
list_add_tail(&desc->desc_node, &tmp_list);
|
||
|
}
|
||
|
|
||
|
spin_lock_bh(&atchan->lock);
|
||
|
atchan->descs_allocated = i;
|
||
|
list_splice(&tmp_list, &atchan->free_list);
|
||
|
atchan->completed_cookie = chan->cookie = 1;
|
||
|
spin_unlock_bh(&atchan->lock);
|
||
|
|
||
|
/* channel parameters */
|
||
|
channel_writel(atchan, CFG, ATC_DEFAULT_CFG);
|
||
|
|
||
|
dev_dbg(chan2dev(chan),
|
||
|
"alloc_chan_resources: allocated %d descriptors\n",
|
||
|
atchan->descs_allocated);
|
||
|
|
||
|
return atchan->descs_allocated;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* atc_free_chan_resources - free all channel resources
|
||
|
* @chan: DMA channel
|
||
|
*/
|
||
|
static void atc_free_chan_resources(struct dma_chan *chan)
|
||
|
{
|
||
|
struct at_dma_chan *atchan = to_at_dma_chan(chan);
|
||
|
struct at_dma *atdma = to_at_dma(chan->device);
|
||
|
struct at_desc *desc, *_desc;
|
||
|
LIST_HEAD(list);
|
||
|
|
||
|
dev_dbg(chan2dev(chan), "free_chan_resources: (descs allocated=%u)\n",
|
||
|
atchan->descs_allocated);
|
||
|
|
||
|
/* ASSERT: channel is idle */
|
||
|
BUG_ON(!list_empty(&atchan->active_list));
|
||
|
BUG_ON(!list_empty(&atchan->queue));
|
||
|
BUG_ON(atc_chan_is_enabled(atchan));
|
||
|
|
||
|
list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
|
||
|
dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
|
||
|
list_del(&desc->desc_node);
|
||
|
/* free link descriptor */
|
||
|
dma_pool_free(atdma->dma_desc_pool, desc, desc->txd.phys);
|
||
|
}
|
||
|
list_splice_init(&atchan->free_list, &list);
|
||
|
atchan->descs_allocated = 0;
|
||
|
|
||
|
dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
|
||
|
}
|
||
|
|
||
|
|
||
|
/*-- Module Management -----------------------------------------------*/
|
||
|
|
||
|
/**
|
||
|
* at_dma_off - disable DMA controller
|
||
|
* @atdma: the Atmel HDAMC device
|
||
|
*/
|
||
|
static void at_dma_off(struct at_dma *atdma)
|
||
|
{
|
||
|
dma_writel(atdma, EN, 0);
|
||
|
|
||
|
/* disable all interrupts */
|
||
|
dma_writel(atdma, EBCIDR, -1L);
|
||
|
|
||
|
/* confirm that all channels are disabled */
|
||
|
while (dma_readl(atdma, CHSR) & atdma->all_chan_mask)
|
||
|
cpu_relax();
|
||
|
}
|
||
|
|
||
|
static int __init at_dma_probe(struct platform_device *pdev)
|
||
|
{
|
||
|
struct at_dma_platform_data *pdata;
|
||
|
struct resource *io;
|
||
|
struct at_dma *atdma;
|
||
|
size_t size;
|
||
|
int irq;
|
||
|
int err;
|
||
|
int i;
|
||
|
|
||
|
/* get DMA Controller parameters from platform */
|
||
|
pdata = pdev->dev.platform_data;
|
||
|
if (!pdata || pdata->nr_channels > AT_DMA_MAX_NR_CHANNELS)
|
||
|
return -EINVAL;
|
||
|
|
||
|
io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
||
|
if (!io)
|
||
|
return -EINVAL;
|
||
|
|
||
|
irq = platform_get_irq(pdev, 0);
|
||
|
if (irq < 0)
|
||
|
return irq;
|
||
|
|
||
|
size = sizeof(struct at_dma);
|
||
|
size += pdata->nr_channels * sizeof(struct at_dma_chan);
|
||
|
atdma = kzalloc(size, GFP_KERNEL);
|
||
|
if (!atdma)
|
||
|
return -ENOMEM;
|
||
|
|
||
|
/* discover transaction capabilites from the platform data */
|
||
|
atdma->dma_common.cap_mask = pdata->cap_mask;
|
||
|
atdma->all_chan_mask = (1 << pdata->nr_channels) - 1;
|
||
|
|
||
|
size = io->end - io->start + 1;
|
||
|
if (!request_mem_region(io->start, size, pdev->dev.driver->name)) {
|
||
|
err = -EBUSY;
|
||
|
goto err_kfree;
|
||
|
}
|
||
|
|
||
|
atdma->regs = ioremap(io->start, size);
|
||
|
if (!atdma->regs) {
|
||
|
err = -ENOMEM;
|
||
|
goto err_release_r;
|
||
|
}
|
||
|
|
||
|
atdma->clk = clk_get(&pdev->dev, "dma_clk");
|
||
|
if (IS_ERR(atdma->clk)) {
|
||
|
err = PTR_ERR(atdma->clk);
|
||
|
goto err_clk;
|
||
|
}
|
||
|
clk_enable(atdma->clk);
|
||
|
|
||
|
/* force dma off, just in case */
|
||
|
at_dma_off(atdma);
|
||
|
|
||
|
err = request_irq(irq, at_dma_interrupt, 0, "at_hdmac", atdma);
|
||
|
if (err)
|
||
|
goto err_irq;
|
||
|
|
||
|
platform_set_drvdata(pdev, atdma);
|
||
|
|
||
|
/* create a pool of consistent memory blocks for hardware descriptors */
|
||
|
atdma->dma_desc_pool = dma_pool_create("at_hdmac_desc_pool",
|
||
|
&pdev->dev, sizeof(struct at_desc),
|
||
|
4 /* word alignment */, 0);
|
||
|
if (!atdma->dma_desc_pool) {
|
||
|
dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
|
||
|
err = -ENOMEM;
|
||
|
goto err_pool_create;
|
||
|
}
|
||
|
|
||
|
/* clear any pending interrupt */
|
||
|
while (dma_readl(atdma, EBCISR))
|
||
|
cpu_relax();
|
||
|
|
||
|
/* initialize channels related values */
|
||
|
INIT_LIST_HEAD(&atdma->dma_common.channels);
|
||
|
for (i = 0; i < pdata->nr_channels; i++, atdma->dma_common.chancnt++) {
|
||
|
struct at_dma_chan *atchan = &atdma->chan[i];
|
||
|
|
||
|
atchan->chan_common.device = &atdma->dma_common;
|
||
|
atchan->chan_common.cookie = atchan->completed_cookie = 1;
|
||
|
atchan->chan_common.chan_id = i;
|
||
|
list_add_tail(&atchan->chan_common.device_node,
|
||
|
&atdma->dma_common.channels);
|
||
|
|
||
|
atchan->ch_regs = atdma->regs + ch_regs(i);
|
||
|
spin_lock_init(&atchan->lock);
|
||
|
atchan->mask = 1 << i;
|
||
|
|
||
|
INIT_LIST_HEAD(&atchan->active_list);
|
||
|
INIT_LIST_HEAD(&atchan->queue);
|
||
|
INIT_LIST_HEAD(&atchan->free_list);
|
||
|
|
||
|
tasklet_init(&atchan->tasklet, atc_tasklet,
|
||
|
(unsigned long)atchan);
|
||
|
atc_enable_irq(atchan);
|
||
|
}
|
||
|
|
||
|
/* set base routines */
|
||
|
atdma->dma_common.device_alloc_chan_resources = atc_alloc_chan_resources;
|
||
|
atdma->dma_common.device_free_chan_resources = atc_free_chan_resources;
|
||
|
atdma->dma_common.device_is_tx_complete = atc_is_tx_complete;
|
||
|
atdma->dma_common.device_issue_pending = atc_issue_pending;
|
||
|
atdma->dma_common.dev = &pdev->dev;
|
||
|
|
||
|
/* set prep routines based on capability */
|
||
|
if (dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask))
|
||
|
atdma->dma_common.device_prep_dma_memcpy = atc_prep_dma_memcpy;
|
||
|
|
||
|
dma_writel(atdma, EN, AT_DMA_ENABLE);
|
||
|
|
||
|
dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s), %d channels\n",
|
||
|
dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "",
|
||
|
dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask) ? "slave " : "",
|
||
|
atdma->dma_common.chancnt);
|
||
|
|
||
|
dma_async_device_register(&atdma->dma_common);
|
||
|
|
||
|
return 0;
|
||
|
|
||
|
err_pool_create:
|
||
|
platform_set_drvdata(pdev, NULL);
|
||
|
free_irq(platform_get_irq(pdev, 0), atdma);
|
||
|
err_irq:
|
||
|
clk_disable(atdma->clk);
|
||
|
clk_put(atdma->clk);
|
||
|
err_clk:
|
||
|
iounmap(atdma->regs);
|
||
|
atdma->regs = NULL;
|
||
|
err_release_r:
|
||
|
release_mem_region(io->start, size);
|
||
|
err_kfree:
|
||
|
kfree(atdma);
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static int __exit at_dma_remove(struct platform_device *pdev)
|
||
|
{
|
||
|
struct at_dma *atdma = platform_get_drvdata(pdev);
|
||
|
struct dma_chan *chan, *_chan;
|
||
|
struct resource *io;
|
||
|
|
||
|
at_dma_off(atdma);
|
||
|
dma_async_device_unregister(&atdma->dma_common);
|
||
|
|
||
|
dma_pool_destroy(atdma->dma_desc_pool);
|
||
|
platform_set_drvdata(pdev, NULL);
|
||
|
free_irq(platform_get_irq(pdev, 0), atdma);
|
||
|
|
||
|
list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
|
||
|
device_node) {
|
||
|
struct at_dma_chan *atchan = to_at_dma_chan(chan);
|
||
|
|
||
|
/* Disable interrupts */
|
||
|
atc_disable_irq(atchan);
|
||
|
tasklet_disable(&atchan->tasklet);
|
||
|
|
||
|
tasklet_kill(&atchan->tasklet);
|
||
|
list_del(&chan->device_node);
|
||
|
}
|
||
|
|
||
|
clk_disable(atdma->clk);
|
||
|
clk_put(atdma->clk);
|
||
|
|
||
|
iounmap(atdma->regs);
|
||
|
atdma->regs = NULL;
|
||
|
|
||
|
io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
||
|
release_mem_region(io->start, io->end - io->start + 1);
|
||
|
|
||
|
kfree(atdma);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static void at_dma_shutdown(struct platform_device *pdev)
|
||
|
{
|
||
|
struct at_dma *atdma = platform_get_drvdata(pdev);
|
||
|
|
||
|
at_dma_off(platform_get_drvdata(pdev));
|
||
|
clk_disable(atdma->clk);
|
||
|
}
|
||
|
|
||
|
static int at_dma_suspend_late(struct platform_device *pdev, pm_message_t mesg)
|
||
|
{
|
||
|
struct at_dma *atdma = platform_get_drvdata(pdev);
|
||
|
|
||
|
at_dma_off(platform_get_drvdata(pdev));
|
||
|
clk_disable(atdma->clk);
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int at_dma_resume_early(struct platform_device *pdev)
|
||
|
{
|
||
|
struct at_dma *atdma = platform_get_drvdata(pdev);
|
||
|
|
||
|
clk_enable(atdma->clk);
|
||
|
dma_writel(atdma, EN, AT_DMA_ENABLE);
|
||
|
return 0;
|
||
|
|
||
|
}
|
||
|
|
||
|
static struct platform_driver at_dma_driver = {
|
||
|
.remove = __exit_p(at_dma_remove),
|
||
|
.shutdown = at_dma_shutdown,
|
||
|
.suspend_late = at_dma_suspend_late,
|
||
|
.resume_early = at_dma_resume_early,
|
||
|
.driver = {
|
||
|
.name = "at_hdmac",
|
||
|
},
|
||
|
};
|
||
|
|
||
|
static int __init at_dma_init(void)
|
||
|
{
|
||
|
return platform_driver_probe(&at_dma_driver, at_dma_probe);
|
||
|
}
|
||
|
module_init(at_dma_init);
|
||
|
|
||
|
static void __exit at_dma_exit(void)
|
||
|
{
|
||
|
platform_driver_unregister(&at_dma_driver);
|
||
|
}
|
||
|
module_exit(at_dma_exit);
|
||
|
|
||
|
MODULE_DESCRIPTION("Atmel AHB DMA Controller driver");
|
||
|
MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
|
||
|
MODULE_LICENSE("GPL");
|
||
|
MODULE_ALIAS("platform:at_hdmac");
|