--- /dev/null
+/*
+ * Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems)
+ *
+ * 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.
+ *
+ *
+ * This supports the Atmel AHB DMA Controller,
+ *
+ * The driver has currently been tested with the Atmel AT91SAM9RL
+ * and AT91SAM9G45 series.
+ */
+
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "at_hdmac_regs.h"
+
+/*
+ * Glossary
+ * --------
+ *
+ * at_hdmac : Name of the ATmel AHB DMA Controller
+ * at_dma_ / atdma : ATmel DMA controller entity related
+ * atc_ / atchan : ATmel DMA Channel entity related
+ */
+
+#define ATC_DEFAULT_CFG (ATC_FIFOCFG_HALFFIFO)
+#define ATC_DEFAULT_CTRLA (0)
+#define ATC_DEFAULT_CTRLB (ATC_SIF(0) \
+ |ATC_DIF(1))
+
+/*
+ * Initial number of descriptors to allocate for each channel. This could
+ * be increased during dma usage.
+ */
+static unsigned int init_nr_desc_per_channel = 64;
+module_param(init_nr_desc_per_channel, uint, 0644);
+MODULE_PARM_DESC(init_nr_desc_per_channel,
+ "initial descriptors per channel (default: 64)");
+
+
+/* prototypes */
+static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx);
+
+
+/*----------------------------------------------------------------------*/
+
+static struct at_desc *atc_first_active(struct at_dma_chan *atchan)
+{
+ return list_first_entry(&atchan->active_list,
+ struct at_desc, desc_node);
+}
+
+static struct at_desc *atc_first_queued(struct at_dma_chan *atchan)
+{
+ return list_first_entry(&atchan->queue,
+ struct at_desc, desc_node);
+}
+
+/**
+ * atc_alloc_descriptor - allocate and return an initilized descriptor
+ * @chan: the channel to allocate descriptors for
+ * @gfp_flags: GFP allocation flags
+ *
+ * Note: The ack-bit is positioned in the descriptor flag at creation time
+ * to make initial allocation more convenient. This bit will be cleared
+ * and control will be given to client at usage time (during
+ * preparation functions).
+ */
+static struct at_desc *atc_alloc_descriptor(struct dma_chan *chan,
+ gfp_t gfp_flags)
+{
+ struct at_desc *desc = NULL;
+ struct at_dma *atdma = to_at_dma(chan->device);
+ dma_addr_t phys;
+
+ desc = dma_pool_alloc(atdma->dma_desc_pool, gfp_flags, &phys);
+ if (desc) {
+ memset(desc, 0, sizeof(struct at_desc));
+ dma_async_tx_descriptor_init(&desc->txd, chan);
+ /* txd.flags will be overwritten in prep functions */
+ desc->txd.flags = DMA_CTRL_ACK;
+ desc->txd.tx_submit = atc_tx_submit;
+ desc->txd.phys = phys;
+ }
+
+ return desc;
+}
+
+/**
+ * atc_desc_get - get a unsused descriptor from free_list
+ * @atchan: channel we want a new descriptor for
+ */
+static struct at_desc *atc_desc_get(struct at_dma_chan *atchan)
+{
+ struct at_desc *desc, *_desc;
+ struct at_desc *ret = NULL;
+ unsigned int i = 0;
+ LIST_HEAD(tmp_list);
+
+ spin_lock_bh(&atchan->lock);
+ list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
+ i++;
+ if (async_tx_test_ack(&desc->txd)) {
+ list_del(&desc->desc_node);
+ ret = desc;
+ break;
+ }
+ dev_dbg(chan2dev(&atchan->chan_common),
+ "desc %p not ACKed\n", desc);
+ }
+ spin_unlock_bh(&atchan->lock);
+ dev_vdbg(chan2dev(&atchan->chan_common),
+ "scanned %u descriptors on freelist\n", i);
+
+ /* no more descriptor available in initial pool: create one more */
+ if (!ret) {
+ ret = atc_alloc_descriptor(&atchan->chan_common, GFP_ATOMIC);
+ if (ret) {
+ spin_lock_bh(&atchan->lock);
+ atchan->descs_allocated++;
+ spin_unlock_bh(&atchan->lock);
+ } else {
+ dev_err(chan2dev(&atchan->chan_common),
+ "not enough descriptors available\n");
+ }
+ }
+
+ return ret;
+}
+
+/**
+ * atc_desc_put - move a descriptor, including any children, to the free list
+ * @atchan: channel we work on
+ * @desc: descriptor, at the head of a chain, to move to free list
+ */
+static void atc_desc_put(struct at_dma_chan *atchan, struct at_desc *desc)
+{
+ if (desc) {
+ struct at_desc *child;
+
+ spin_lock_bh(&atchan->lock);
+ list_for_each_entry(child, &desc->txd.tx_list, desc_node)
+ dev_vdbg(chan2dev(&atchan->chan_common),
+ "moving child desc %p to freelist\n",
+ child);
+ list_splice_init(&desc->txd.tx_list, &atchan->free_list);
+ dev_vdbg(chan2dev(&atchan->chan_common),
+ "moving desc %p to freelist\n", desc);
+ list_add(&desc->desc_node, &atchan->free_list);
+ spin_unlock_bh(&atchan->lock);
+ }
+}
+
+/**
+ * atc_assign_cookie - compute and assign new cookie
+ * @atchan: channel we work on
+ * @desc: descriptor to asign cookie for
+ *
+ * Called with atchan->lock held and bh disabled
+ */
+static dma_cookie_t
+atc_assign_cookie(struct at_dma_chan *atchan, struct at_desc *desc)
+{
+ dma_cookie_t cookie = atchan->chan_common.cookie;
+
+ if (++cookie < 0)
+ cookie = 1;
+
+ atchan->chan_common.cookie = cookie;
+ desc->txd.cookie = cookie;
+
+ return cookie;
+}
+
+/**
+ * atc_dostart - starts the DMA engine for real
+ * @atchan: the channel we want to start
+ * @first: first descriptor in the list we want to begin with
+ *
+ * Called with atchan->lock held and bh disabled
+ */
+static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
+{
+ struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
+
+ /* ASSERT: channel is idle */
+ if (atc_chan_is_enabled(atchan)) {
+ dev_err(chan2dev(&atchan->chan_common),
+ "BUG: Attempted to start non-idle channel\n");
+ 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));
+
+ /* The tasklet will hopefully advance the queue... */
+ return;
+ }
+
+ vdbg_dump_regs(atchan);
+
+ /* clear any pending interrupt */
+ while (dma_readl(atdma, EBCISR))
+ cpu_relax();
+
+ channel_writel(atchan, SADDR, 0);
+ channel_writel(atchan, DADDR, 0);
+ channel_writel(atchan, CTRLA, 0);
+ channel_writel(atchan, CTRLB, 0);
+ channel_writel(atchan, DSCR, first->txd.phys);
+ dma_writel(atdma, CHER, atchan->mask);
+
+ vdbg_dump_regs(atchan);
+}
+
+/**
+ * atc_chain_complete - finish work for one transaction chain
+ * @atchan: channel we work on
+ * @desc: descriptor at the head of the chain we want do complete
+ *
+ * Called with atchan->lock held and bh disabled */
+static void
+atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
+{
+ dma_async_tx_callback callback;
+ void *param;
+ struct dma_async_tx_descriptor *txd = &desc->txd;
+
+ dev_vdbg(chan2dev(&atchan->chan_common),
+ "descriptor %u complete\n", txd->cookie);
+
+ atchan->completed_cookie = txd->cookie;
+ callback = txd->callback;
+ param = txd->callback_param;
+
+ /* move children to free_list */
+ list_splice_init(&txd->tx_list, &atchan->free_list);
+ /* move myself to free_list */
+ list_move(&desc->desc_node, &atchan->free_list);
+
+ /* unmap dma addresses */
+ if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
+ if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
+ dma_unmap_single(chan2parent(&atchan->chan_common),
+ desc->lli.daddr,
+ desc->len, DMA_FROM_DEVICE);
+ else
+ dma_unmap_page(chan2parent(&atchan->chan_common),
+ desc->lli.daddr,
+ desc->len, DMA_FROM_DEVICE);
+ }
+ if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
+ if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
+ dma_unmap_single(chan2parent(&atchan->chan_common),
+ desc->lli.saddr,
+ desc->len, DMA_TO_DEVICE);
+ else
+ dma_unmap_page(chan2parent(&atchan->chan_common),
+ desc->lli.saddr,
+ desc->len, DMA_TO_DEVICE);
+ }
+
+ /*
+ * The API requires that no submissions are done from a
+ * callback, so we don't need to drop the lock here
+ */
+ if (callback)
+ callback(param);
+
+ dma_run_dependencies(txd);
+}
+
+/**
+ * atc_complete_all - finish work for all transactions
+ * @atchan: channel to complete transactions for
+ *
+ * Eventually submit queued descriptors if any
+ *
+ * Assume channel is idle while calling this function
+ * Called with atchan->lock held and bh disabled
+ */
+static void atc_complete_all(struct at_dma_chan *atchan)
+{
+ struct at_desc *desc, *_desc;
+ LIST_HEAD(list);
+
+ dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
+
+ BUG_ON(atc_chan_is_enabled(atchan));
+
+ /*
+ * Submit queued descriptors ASAP, i.e. before we go through
+ * the completed ones.
+ */
+ if (!list_empty(&atchan->queue))
+ atc_dostart(atchan, atc_first_queued(atchan));
+ /* empty active_list now it is completed */
+ list_splice_init(&atchan->active_list, &list);
+ /* empty queue list by moving descriptors (if any) to active_list */
+ list_splice_init(&atchan->queue, &atchan->active_list);
+
+ list_for_each_entry_safe(desc, _desc, &list, desc_node)
+ atc_chain_complete(atchan, desc);
+}
+
+/**
+ * atc_cleanup_descriptors - cleanup up finished descriptors in active_list
+ * @atchan: channel to be cleaned up
+ *
+ * Called with atchan->lock held and bh disabled
+ */
+static void atc_cleanup_descriptors(struct at_dma_chan *atchan)
+{
+ struct at_desc *desc, *_desc;
+ struct at_desc *child;
+
+ dev_vdbg(chan2dev(&atchan->chan_common), "cleanup descriptors\n");
+
+ list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
+ if (!(desc->lli.ctrla & ATC_DONE))
+ /* This one is currently in progress */
+ return;
+
+ list_for_each_entry(child, &desc->txd.tx_list, desc_node)
+ if (!(child->lli.ctrla & ATC_DONE))
+ /* Currently in progress */
+ return;
+
+ /*
+ * No descriptors so far seem to be in progress, i.e.
+ * this chain must be done.
+ */
+ atc_chain_complete(atchan, desc);
+ }
+}
+
+/**
+ * atc_advance_work - at the end of a transaction, move forward
+ * @atchan: channel where the transaction ended
+ *
+ * Called with atchan->lock held and bh disabled
+ */
+static void atc_advance_work(struct at_dma_chan *atchan)
+{
+ dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
+
+ if (list_empty(&atchan->active_list) ||
+ list_is_singular(&atchan->active_list)) {
+ atc_complete_all(atchan);
+ } else {
+ atc_chain_complete(atchan, atc_first_active(atchan));
+ /* advance work */
+ atc_dostart(atchan, atc_first_active(atchan));
+ }
+}
+
+
+/**
+ * atc_handle_error - handle errors reported by DMA controller
+ * @atchan: channel where error occurs
+ *
+ * Called with atchan->lock held and bh disabled
+ */
+static void atc_handle_error(struct at_dma_chan *atchan)
+{
+ struct at_desc *bad_desc;
+ struct at_desc *child;
+
+ /*
+ * The descriptor currently at the head of the active list is
+ * broked. Since we don't have any way to report errors, we'll
+ * just have to scream loudly and try to carry on.
+ */
+ bad_desc = atc_first_active(atchan);
+ list_del_init(&bad_desc->desc_node);
+
+ /* As we are stopped, take advantage to push queued descriptors
+ * in active_list */
+ list_splice_init(&atchan->queue, atchan->active_list.prev);
+
+ /* 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
+ * 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_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
+ * @chan: DMA channel
+ * @sgl: scatterlist to transfer to/from
+ * @sg_len: number of entries in @scatterlist
+ * @direction: DMA direction
+ * @flags: tx descriptor status flags
+ */
+static struct dma_async_tx_descriptor *
+atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_data_direction direction,
+ unsigned long flags)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_dma_slave *atslave = chan->private;
+ struct at_desc *first = NULL;
+ struct at_desc *prev = NULL;
+ u32 ctrla;
+ u32 ctrlb;
+ dma_addr_t reg;
+ unsigned int reg_width;
+ unsigned int mem_width;
+ unsigned int i;
+ struct scatterlist *sg;
+ size_t total_len = 0;
+
+ dev_vdbg(chan2dev(chan), "prep_slave_sg: %s f0x%lx\n",
+ direction == DMA_TO_DEVICE ? "TO DEVICE" : "FROM DEVICE",
+ flags);
+
+ if (unlikely(!atslave || !sg_len)) {
+ dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
+ return NULL;
+ }
+
+ reg_width = atslave->reg_width;
+
+ sg_len = dma_map_sg(chan2parent(chan), sgl, sg_len, direction);
+
+ ctrla = ATC_DEFAULT_CTRLA | atslave->ctrla;
+ ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN;
+
+ switch (direction) {
+ case DMA_TO_DEVICE:
+ ctrla |= ATC_DST_WIDTH(reg_width);
+ ctrlb |= ATC_DST_ADDR_MODE_FIXED
+ | ATC_SRC_ADDR_MODE_INCR
+ | ATC_FC_MEM2PER;
+ reg = atslave->tx_reg;
+ for_each_sg(sgl, sg, sg_len, i) {
+ struct at_desc *desc;
+ u32 len;
+ u32 mem;
+
+ desc = atc_desc_get(atchan);
+ if (!desc)
+ goto err_desc_get;
+
+ mem = sg_phys(sg);
+ len = sg_dma_len(sg);
+ mem_width = 2;
+ if (unlikely(mem & 3 || len & 3))
+ mem_width = 0;
+
+ desc->lli.saddr = mem;
+ desc->lli.daddr = reg;
+ desc->lli.ctrla = ctrla
+ | ATC_SRC_WIDTH(mem_width)
+ | len >> mem_width;
+ desc->lli.ctrlb = ctrlb;
+
+ 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;
+ total_len += len;
+ }
+ break;
+ case DMA_FROM_DEVICE:
+ ctrla |= ATC_SRC_WIDTH(reg_width);
+ ctrlb |= ATC_DST_ADDR_MODE_INCR
+ | ATC_SRC_ADDR_MODE_FIXED
+ | ATC_FC_PER2MEM;
+
+ reg = atslave->rx_reg;
+ for_each_sg(sgl, sg, sg_len, i) {
+ struct at_desc *desc;
+ u32 len;
+ u32 mem;
+
+ desc = atc_desc_get(atchan);
+ if (!desc)
+ goto err_desc_get;
+
+ mem = sg_phys(sg);
+ len = sg_dma_len(sg);
+ mem_width = 2;
+ if (unlikely(mem & 3 || len & 3))
+ mem_width = 0;
+
+ desc->lli.saddr = reg;
+ desc->lli.daddr = mem;
+ desc->lli.ctrla = ctrla
+ | ATC_DST_WIDTH(mem_width)
+ | len >> mem_width;
+ desc->lli.ctrlb = ctrlb;
+
+ 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;
+ total_len += len;
+ }
+ break;
+ default:
+ return NULL;
+ }
+
+ /* set end-of-link to the last link descriptor of list*/
+ set_desc_eol(prev);
+
+ /* First descriptor of the chain embedds additional information */
+ first->txd.cookie = -EBUSY;
+ first->len = total_len;
+
+ /* last link descriptor of list is responsible of flags */
+ prev->txd.flags = flags; /* client is in control of this ack */
+
+ return &first->txd;
+
+err_desc_get:
+ dev_err(chan2dev(chan), "not enough descriptors available\n");
+ atc_desc_put(atchan, first);
+ return NULL;
+}
+
+static void atc_terminate_all(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);
+
+ /*
+ * This is only called when something went wrong elsewhere, so
+ * we don't really care about the data. Just disable the
+ * channel. We still have to poll the channel enable bit due
+ * to AHB/HSB limitations.
+ */
+ spin_lock_bh(&atchan->lock);
+
+ dma_writel(atdma, CHDR, atchan->mask);
+
+ /* confirm that this channel is disabled */
+ while (dma_readl(atdma, CHSR) & atchan->mask)
+ cpu_relax();
+
+ /* active_list entries will end up before queued entries */
+ list_splice_init(&atchan->queue, &list);
+ list_splice_init(&atchan->active_list, &list);
+
+ spin_unlock_bh(&atchan->lock);
+
+ /* Flush all pending and queued descriptors */
+ list_for_each_entry_safe(desc, _desc, &list, desc_node)
+ atc_chain_complete(atchan, desc);
+}
+
+/**
+ * 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;
+ struct at_dma_slave *atslave;
+ int i;
+ u32 cfg;
+ 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;
+ }
+
+ cfg = ATC_DEFAULT_CFG;
+
+ atslave = chan->private;
+ if (atslave) {
+ /*
+ * We need controller-specific data to set up slave
+ * transfers.
+ */
+ BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_common.dev);
+
+ /* if cfg configuration specified take it instad of default */
+ if (atslave->cfg)
+ cfg = atslave->cfg;
+ }
+
+ /* have we already been set up?
+ * reconfigure channel but no need to reallocate descriptors */
+ 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, 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;
+
+ if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)) {
+ atdma->dma_common.device_prep_slave_sg = atc_prep_slave_sg;
+ atdma->dma_common.device_terminate_all = atc_terminate_all;
+ }
+
+ 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");
--- /dev/null
+/*
+ * 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 */
+/* Chunck Tranfer size definitions are in at_hdmac.h */
+#define ATC_SRC_WIDTH_MASK (0x3 << 24) /* Source Single Transfer Size */
+#define ATC_SRC_WIDTH(x) ((x) << 24)
+#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(x) ((x) << 28)
+#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_SRCPER (0x6 << 21) /* Periph-to-Periph (Src Peripheral) */
+#define ATC_FC_PER2PER_DSTPER (0x7 << 21) /* Periph-to-Periph (Dst 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 */
+/* are in at_hdmac.h */
+
+/* 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 cfg0x%x l0x%x\n",
+ channel_readl(atchan, SADDR),
+ channel_readl(atchan, DADDR),
+ channel_readl(atchan, CTRLA),
+ channel_readl(atchan, CTRLB),
+ channel_readl(atchan, CFG),
+ 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 */
projects / linux-2.6-block.git / commitdiff