--- /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 found in several Atmel SoCs.
+ * The only Atmel DMA Controller that is not covered by this driver is the one
+ * found on AT91SAM9263.
+ */
+
+#include <dt-bindings/dma/at91.h>
+#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 <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+
+#include "at_hdmac_regs.h"
+#include "dmaengine.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_CTRLB (ATC_SIF(AT_DMA_MEM_IF) \
+ |ATC_DIF(AT_DMA_MEM_IF))
+#define ATC_DMA_BUSWIDTHS\
+ (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\
+ BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |\
+ BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |\
+ BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
+
+/*
+ * 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 void atc_issue_pending(struct dma_chan *chan);
+
+
+/*----------------------------------------------------------------------*/
+
+static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst,
+ size_t len)
+{
+ unsigned int width;
+
+ if (!((src | dst | len) & 3))
+ width = 2;
+ else if (!((src | dst | len) & 1))
+ width = 1;
+ else
+ width = 0;
+
+ return width;
+}
+
+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 initialized 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));
+ INIT_LIST_HEAD(&desc->tx_list);
+ 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 an unused 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 long flags;
+ unsigned int i = 0;
+ LIST_HEAD(tmp_list);
+
+ spin_lock_irqsave(&atchan->lock, flags);
+ 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_irqrestore(&atchan->lock, flags);
+ 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_irqsave(&atchan->lock, flags);
+ atchan->descs_allocated++;
+ spin_unlock_irqrestore(&atchan->lock, flags);
+ } 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;
+ unsigned long flags;
+
+ spin_lock_irqsave(&atchan->lock, flags);
+ list_for_each_entry(child, &desc->tx_list, desc_node)
+ dev_vdbg(chan2dev(&atchan->chan_common),
+ "moving child desc %p to freelist\n",
+ child);
+ list_splice_init(&desc->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_irqrestore(&atchan->lock, flags);
+ }
+}
+
+/**
+ * atc_desc_chain - build chain adding a descriptor
+ * @first: address of first descriptor of the chain
+ * @prev: address of previous descriptor of the chain
+ * @desc: descriptor to queue
+ *
+ * Called from prep_* functions
+ */
+static void atc_desc_chain(struct at_desc **first, struct at_desc **prev,
+ struct at_desc *desc)
+{
+ 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)->tx_list);
+ }
+ *prev = desc;
+}
+
+/**
+ * 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);
+
+ 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_get_desc_by_cookie - get the descriptor of a cookie
+ * @atchan: the DMA channel
+ * @cookie: the cookie to get the descriptor for
+ */
+static struct at_desc *atc_get_desc_by_cookie(struct at_dma_chan *atchan,
+ dma_cookie_t cookie)
+{
+ struct at_desc *desc, *_desc;
+
+ list_for_each_entry_safe(desc, _desc, &atchan->queue, desc_node) {
+ if (desc->txd.cookie == cookie)
+ return desc;
+ }
+
+ list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
+ if (desc->txd.cookie == cookie)
+ return desc;
+ }
+
+ return NULL;
+}
+
+/**
+ * atc_calc_bytes_left - calculates the number of bytes left according to the
+ * value read from CTRLA.
+ *
+ * @current_len: the number of bytes left before reading CTRLA
+ * @ctrla: the value of CTRLA
+ * @desc: the descriptor containing the transfer width
+ */
+static inline int atc_calc_bytes_left(int current_len, u32 ctrla,
+ struct at_desc *desc)
+{
+ return current_len - ((ctrla & ATC_BTSIZE_MAX) << desc->tx_width);
+}
+
+/**
+ * atc_calc_bytes_left_from_reg - calculates the number of bytes left according
+ * to the current value of CTRLA.
+ *
+ * @current_len: the number of bytes left before reading CTRLA
+ * @atchan: the channel to read CTRLA for
+ * @desc: the descriptor containing the transfer width
+ */
+static inline int atc_calc_bytes_left_from_reg(int current_len,
+ struct at_dma_chan *atchan, struct at_desc *desc)
+{
+ u32 ctrla = channel_readl(atchan, CTRLA);
+
+ return atc_calc_bytes_left(current_len, ctrla, desc);
+}
+
+/**
+ * atc_get_bytes_left - get the number of bytes residue for a cookie
+ * @chan: DMA channel
+ * @cookie: transaction identifier to check status of
+ */
+static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_desc *desc_first = atc_first_active(atchan);
+ struct at_desc *desc;
+ int ret;
+ u32 ctrla, dscr;
+
+ /*
+ * If the cookie doesn't match to the currently running transfer then
+ * we can return the total length of the associated DMA transfer,
+ * because it is still queued.
+ */
+ desc = atc_get_desc_by_cookie(atchan, cookie);
+ if (desc == NULL)
+ return -EINVAL;
+ else if (desc != desc_first)
+ return desc->total_len;
+
+ /* cookie matches to the currently running transfer */
+ ret = desc_first->total_len;
+
+ if (desc_first->lli.dscr) {
+ /* hardware linked list transfer */
+
+ /*
+ * Calculate the residue by removing the length of the child
+ * descriptors already transferred from the total length.
+ * To get the current child descriptor we can use the value of
+ * the channel's DSCR register and compare it against the value
+ * of the hardware linked list structure of each child
+ * descriptor.
+ */
+
+ ctrla = channel_readl(atchan, CTRLA);
+ rmb(); /* ensure CTRLA is read before DSCR */
+ dscr = channel_readl(atchan, DSCR);
+
+ /* for the first descriptor we can be more accurate */
+ if (desc_first->lli.dscr == dscr)
+ return atc_calc_bytes_left(ret, ctrla, desc_first);
+
+ ret -= desc_first->len;
+ list_for_each_entry(desc, &desc_first->tx_list, desc_node) {
+ if (desc->lli.dscr == dscr)
+ break;
+
+ ret -= desc->len;
+ }
+
+ /*
+ * For the last descriptor in the chain we can calculate
+ * the remaining bytes using the channel's register.
+ * Note that the transfer width of the first and last
+ * descriptor may differ.
+ */
+ if (!desc->lli.dscr)
+ ret = atc_calc_bytes_left_from_reg(ret, atchan, desc);
+ } else {
+ /* single transfer */
+ ret = atc_calc_bytes_left_from_reg(ret, atchan, desc_first);
+ }
+
+ return ret;
+}
+
+/**
+ * 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)
+{
+ struct dma_async_tx_descriptor *txd = &desc->txd;
+
+ dev_vdbg(chan2dev(&atchan->chan_common),
+ "descriptor %u complete\n", txd->cookie);
+
+ /* mark the descriptor as complete for non cyclic cases only */
+ if (!atc_chan_is_cyclic(atchan))
+ dma_cookie_complete(txd);
+
+ /* move children to free_list */
+ list_splice_init(&desc->tx_list, &atchan->free_list);
+ /* move myself to free_list */
+ list_move(&desc->desc_node, &atchan->free_list);
+
+ dma_descriptor_unmap(txd);
+ /* for cyclic transfers,
+ * no need to replay callback function while stopping */
+ if (!atc_chan_is_cyclic(atchan)) {
+ dma_async_tx_callback callback = txd->callback;
+ void *param = txd->callback_param;
+
+ /*
+ * 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");
+
+ /*
+ * 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_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 (atc_chan_is_enabled(atchan))
+ return;
+
+ 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->tx_list, desc_node)
+ atc_dump_lli(atchan, &child->lli);
+
+ /* Pretend the descriptor completed successfully */
+ atc_chain_complete(atchan, bad_desc);
+}
+
+/**
+ * atc_handle_cyclic - at the end of a period, run callback function
+ * @atchan: channel used for cyclic operations
+ *
+ * Called with atchan->lock held and bh disabled
+ */
+static void atc_handle_cyclic(struct at_dma_chan *atchan)
+{
+ struct at_desc *first = atc_first_active(atchan);
+ struct dma_async_tx_descriptor *txd = &first->txd;
+ dma_async_tx_callback callback = txd->callback;
+ void *param = txd->callback_param;
+
+ dev_vdbg(chan2dev(&atchan->chan_common),
+ "new cyclic period llp 0x%08x\n",
+ channel_readl(atchan, DSCR));
+
+ if (callback)
+ callback(param);
+}
+
+/*-- IRQ & Tasklet ---------------------------------------------------*/
+
+static void atc_tasklet(unsigned long data)
+{
+ struct at_dma_chan *atchan = (struct at_dma_chan *)data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&atchan->lock, flags);
+ if (test_and_clear_bit(ATC_IS_ERROR, &atchan->status))
+ atc_handle_error(atchan);
+ else if (atc_chan_is_cyclic(atchan))
+ atc_handle_cyclic(atchan);
+ else
+ atc_advance_work(atchan);
+
+ spin_unlock_irqrestore(&atchan->lock, flags);
+}
+
+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_BTC(i) | AT_DMA_ERR(i))) {
+ if (pending & AT_DMA_ERR(i)) {
+ /* Disable channel on AHB error */
+ dma_writel(atdma, CHDR,
+ AT_DMA_RES(i) | atchan->mask);
+ /* Give information to tasklet */
+ set_bit(ATC_IS_ERROR, &atchan->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;
+ unsigned long flags;
+
+ spin_lock_irqsave(&atchan->lock, flags);
+ cookie = dma_cookie_assign(tx);
+
+ 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_irqrestore(&atchan->lock, flags);
+
+ 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;
+ }
+
+ ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN
+ | 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.
+ */
+ src_width = dst_width = atc_get_xfer_width(src, dest, len);
+
+ ctrla = ATC_SRC_WIDTH(src_width) |
+ ATC_DST_WIDTH(dst_width);
+
+ 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;
+ desc->len = xfer_count << src_width;
+
+ atc_desc_chain(&first, &prev, desc);
+ }
+
+ /* First descriptor of the chain embedds additional information */
+ first->txd.cookie = -EBUSY;
+ first->total_len = len;
+
+ /* set transfer width for the calculation of the residue */
+ first->tx_width = src_width;
+ prev->tx_width = src_width;
+
+ /* set end-of-link to the last link descriptor of list*/
+ set_desc_eol(desc);
+
+ first->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
+ * @context: transaction context (ignored)
+ */
+static struct dma_async_tx_descriptor *
+atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_transfer_direction direction,
+ unsigned long flags, void *context)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_dma_slave *atslave = chan->private;
+ struct dma_slave_config *sconfig = &atchan->dma_sconfig;
+ 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 (%d): %s f0x%lx\n",
+ sg_len,
+ direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE",
+ flags);
+
+ if (unlikely(!atslave || !sg_len)) {
+ dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n");
+ return NULL;
+ }
+
+ ctrla = ATC_SCSIZE(sconfig->src_maxburst)
+ | ATC_DCSIZE(sconfig->dst_maxburst);
+ ctrlb = ATC_IEN;
+
+ switch (direction) {
+ case DMA_MEM_TO_DEV:
+ reg_width = convert_buswidth(sconfig->dst_addr_width);
+ ctrla |= ATC_DST_WIDTH(reg_width);
+ ctrlb |= ATC_DST_ADDR_MODE_FIXED
+ | ATC_SRC_ADDR_MODE_INCR
+ | ATC_FC_MEM2PER
+ | ATC_SIF(atchan->mem_if) | ATC_DIF(atchan->per_if);
+ reg = sconfig->dst_addr;
+ 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_dma_address(sg);
+ len = sg_dma_len(sg);
+ if (unlikely(!len)) {
+ dev_dbg(chan2dev(chan),
+ "prep_slave_sg: sg(%d) data length is zero\n", i);
+ goto err;
+ }
+ 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;
+ desc->len = len;
+
+ atc_desc_chain(&first, &prev, desc);
+ total_len += len;
+ }
+ break;
+ case DMA_DEV_TO_MEM:
+ reg_width = convert_buswidth(sconfig->src_addr_width);
+ ctrla |= ATC_SRC_WIDTH(reg_width);
+ ctrlb |= ATC_DST_ADDR_MODE_INCR
+ | ATC_SRC_ADDR_MODE_FIXED
+ | ATC_FC_PER2MEM
+ | ATC_SIF(atchan->per_if) | ATC_DIF(atchan->mem_if);
+
+ reg = sconfig->src_addr;
+ 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_dma_address(sg);
+ len = sg_dma_len(sg);
+ if (unlikely(!len)) {
+ dev_dbg(chan2dev(chan),
+ "prep_slave_sg: sg(%d) data length is zero\n", i);
+ goto err;
+ }
+ 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 >> reg_width;
+ desc->lli.ctrlb = ctrlb;
+ desc->len = len;
+
+ atc_desc_chain(&first, &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->total_len = total_len;
+
+ /* set transfer width for the calculation of the residue */
+ first->tx_width = reg_width;
+ prev->tx_width = reg_width;
+
+ /* first link descriptor of list is responsible of flags */
+ first->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");
+err:
+ atc_desc_put(atchan, first);
+ return NULL;
+}
+
+/**
+ * atc_prep_dma_sg - prepare memory to memory scather-gather operation
+ * @chan: the channel to prepare operation on
+ * @dst_sg: destination scatterlist
+ * @dst_nents: number of destination scatterlist entries
+ * @src_sg: source scatterlist
+ * @src_nents: number of source scatterlist entries
+ * @flags: tx descriptor status flags
+ */
+static struct dma_async_tx_descriptor *
+atc_prep_dma_sg(struct dma_chan *chan,
+ struct scatterlist *dst_sg, unsigned int dst_nents,
+ struct scatterlist *src_sg, unsigned int src_nents,
+ 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;
+ unsigned int src_width;
+ unsigned int dst_width;
+ size_t xfer_count;
+ u32 ctrla;
+ u32 ctrlb;
+ size_t dst_len = 0, src_len = 0;
+ dma_addr_t dst = 0, src = 0;
+ size_t len = 0, total_len = 0;
+
+ if (unlikely(dst_nents == 0 || src_nents == 0))
+ return NULL;
+
+ if (unlikely(dst_sg == NULL || src_sg == NULL))
+ return NULL;
+
+ ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN
+ | ATC_SRC_ADDR_MODE_INCR
+ | ATC_DST_ADDR_MODE_INCR
+ | ATC_FC_MEM2MEM;
+
+ /*
+ * loop until there is either no more source or no more destination
+ * scatterlist entry
+ */
+ while (true) {
+
+ /* prepare the next transfer */
+ if (dst_len == 0) {
+
+ /* no more destination scatterlist entries */
+ if (!dst_sg || !dst_nents)
+ break;
+
+ dst = sg_dma_address(dst_sg);
+ dst_len = sg_dma_len(dst_sg);
+
+ dst_sg = sg_next(dst_sg);
+ dst_nents--;
+ }
+
+ if (src_len == 0) {
+
+ /* no more source scatterlist entries */
+ if (!src_sg || !src_nents)
+ break;
+
+ src = sg_dma_address(src_sg);
+ src_len = sg_dma_len(src_sg);
+
+ src_sg = sg_next(src_sg);
+ src_nents--;
+ }
+
+ len = min_t(size_t, src_len, dst_len);
+ if (len == 0)
+ continue;
+
+ /* take care for the alignment */
+ src_width = dst_width = atc_get_xfer_width(src, dst, len);
+
+ ctrla = ATC_SRC_WIDTH(src_width) |
+ ATC_DST_WIDTH(dst_width);
+
+ /*
+ * The number of transfers to set up refer to the source width
+ * that depends on the alignment.
+ */
+ xfer_count = len >> src_width;
+ if (xfer_count > ATC_BTSIZE_MAX) {
+ xfer_count = ATC_BTSIZE_MAX;
+ len = ATC_BTSIZE_MAX << src_width;
+ }
+
+ /* create the transfer */
+ desc = atc_desc_get(atchan);
+ if (!desc)
+ goto err_desc_get;
+
+ desc->lli.saddr = src;
+ desc->lli.daddr = dst;
+ desc->lli.ctrla = ctrla | xfer_count;
+ desc->lli.ctrlb = ctrlb;
+
+ desc->txd.cookie = 0;
+ desc->len = len;
+
+ /*
+ * Although we only need the transfer width for the first and
+ * the last descriptor, its easier to set it to all descriptors.
+ */
+ desc->tx_width = src_width;
+
+ atc_desc_chain(&first, &prev, desc);
+
+ /* update the lengths and addresses for the next loop cycle */
+ dst_len -= len;
+ src_len -= len;
+ dst += len;
+ src += len;
+
+ total_len += len;
+ }
+
+ /* First descriptor of the chain embedds additional information */
+ first->txd.cookie = -EBUSY;
+ first->total_len = total_len;
+
+ /* set end-of-link to the last link descriptor of list*/
+ set_desc_eol(desc);
+
+ first->txd.flags = flags; /* client is in control of this ack */
+
+ return &first->txd;
+
+err_desc_get:
+ atc_desc_put(atchan, first);
+ return NULL;
+}
+
+/**
+ * atc_dma_cyclic_check_values
+ * Check for too big/unaligned periods and unaligned DMA buffer
+ */
+static int
+atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr,
+ size_t period_len)
+{
+ if (period_len > (ATC_BTSIZE_MAX << reg_width))
+ goto err_out;
+ if (unlikely(period_len & ((1 << reg_width) - 1)))
+ goto err_out;
+ if (unlikely(buf_addr & ((1 << reg_width) - 1)))
+ goto err_out;
+
+ return 0;
+
+err_out:
+ return -EINVAL;
+}
+
+/**
+ * atc_dma_cyclic_fill_desc - Fill one period descriptor
+ */
+static int
+atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
+ unsigned int period_index, dma_addr_t buf_addr,
+ unsigned int reg_width, size_t period_len,
+ enum dma_transfer_direction direction)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct dma_slave_config *sconfig = &atchan->dma_sconfig;
+ u32 ctrla;
+
+ /* prepare common CRTLA value */
+ ctrla = ATC_SCSIZE(sconfig->src_maxburst)
+ | ATC_DCSIZE(sconfig->dst_maxburst)
+ | ATC_DST_WIDTH(reg_width)
+ | ATC_SRC_WIDTH(reg_width)
+ | period_len >> reg_width;
+
+ switch (direction) {
+ case DMA_MEM_TO_DEV:
+ desc->lli.saddr = buf_addr + (period_len * period_index);
+ desc->lli.daddr = sconfig->dst_addr;
+ desc->lli.ctrla = ctrla;
+ desc->lli.ctrlb = ATC_DST_ADDR_MODE_FIXED
+ | ATC_SRC_ADDR_MODE_INCR
+ | ATC_FC_MEM2PER
+ | ATC_SIF(atchan->mem_if)
+ | ATC_DIF(atchan->per_if);
+ desc->len = period_len;
+ break;
+
+ case DMA_DEV_TO_MEM:
+ desc->lli.saddr = sconfig->src_addr;
+ desc->lli.daddr = buf_addr + (period_len * period_index);
+ desc->lli.ctrla = ctrla;
+ desc->lli.ctrlb = ATC_DST_ADDR_MODE_INCR
+ | ATC_SRC_ADDR_MODE_FIXED
+ | ATC_FC_PER2MEM
+ | ATC_SIF(atchan->per_if)
+ | ATC_DIF(atchan->mem_if);
+ desc->len = period_len;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * atc_prep_dma_cyclic - prepare the cyclic DMA transfer
+ * @chan: the DMA channel to prepare
+ * @buf_addr: physical DMA address where the buffer starts
+ * @buf_len: total number of bytes for the entire buffer
+ * @period_len: number of bytes for each period
+ * @direction: transfer direction, to or from device
+ * @flags: tx descriptor status flags
+ */
+static struct dma_async_tx_descriptor *
+atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len, enum dma_transfer_direction direction,
+ unsigned long flags)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_dma_slave *atslave = chan->private;
+ struct dma_slave_config *sconfig = &atchan->dma_sconfig;
+ struct at_desc *first = NULL;
+ struct at_desc *prev = NULL;
+ unsigned long was_cyclic;
+ unsigned int reg_width;
+ unsigned int periods = buf_len / period_len;
+ unsigned int i;
+
+ dev_vdbg(chan2dev(chan), "prep_dma_cyclic: %s buf@0x%08x - %d (%d/%d)\n",
+ direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE",
+ buf_addr,
+ periods, buf_len, period_len);
+
+ if (unlikely(!atslave || !buf_len || !period_len)) {
+ dev_dbg(chan2dev(chan), "prep_dma_cyclic: length is zero!\n");
+ return NULL;
+ }
+
+ was_cyclic = test_and_set_bit(ATC_IS_CYCLIC, &atchan->status);
+ if (was_cyclic) {
+ dev_dbg(chan2dev(chan), "prep_dma_cyclic: channel in use!\n");
+ return NULL;
+ }
+
+ if (unlikely(!is_slave_direction(direction)))
+ goto err_out;
+
+ if (sconfig->direction == DMA_MEM_TO_DEV)
+ reg_width = convert_buswidth(sconfig->dst_addr_width);
+ else
+ reg_width = convert_buswidth(sconfig->src_addr_width);
+
+ /* Check for too big/unaligned periods and unaligned DMA buffer */
+ if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len))
+ goto err_out;
+
+ /* build cyclic linked list */
+ for (i = 0; i < periods; i++) {
+ struct at_desc *desc;
+
+ desc = atc_desc_get(atchan);
+ if (!desc)
+ goto err_desc_get;
+
+ if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr,
+ reg_width, period_len, direction))
+ goto err_desc_get;
+
+ atc_desc_chain(&first, &prev, desc);
+ }
+
+ /* lets make a cyclic list */
+ prev->lli.dscr = first->txd.phys;
+
+ /* First descriptor of the chain embedds additional information */
+ first->txd.cookie = -EBUSY;
+ first->total_len = buf_len;
+ first->tx_width = reg_width;
+
+ return &first->txd;
+
+err_desc_get:
+ dev_err(chan2dev(chan), "not enough descriptors available\n");
+ atc_desc_put(atchan, first);
+err_out:
+ clear_bit(ATC_IS_CYCLIC, &atchan->status);
+ return NULL;
+}
+
+static int atc_config(struct dma_chan *chan,
+ struct dma_slave_config *sconfig)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+
+ dev_vdbg(chan2dev(chan), "%s\n", __func__);
+
+ /* Check if it is chan is configured for slave transfers */
+ if (!chan->private)
+ return -EINVAL;
+
+ memcpy(&atchan->dma_sconfig, sconfig, sizeof(*sconfig));
+
+ convert_burst(&atchan->dma_sconfig.src_maxburst);
+ convert_burst(&atchan->dma_sconfig.dst_maxburst);
+
+ return 0;
+}
+
+static int atc_pause(struct dma_chan *chan)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_dma *atdma = to_at_dma(chan->device);
+ int chan_id = atchan->chan_common.chan_id;
+ unsigned long flags;
+
+ LIST_HEAD(list);
+
+ dev_vdbg(chan2dev(chan), "%s\n", __func__);
+
+ spin_lock_irqsave(&atchan->lock, flags);
+
+ dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id));
+ set_bit(ATC_IS_PAUSED, &atchan->status);
+
+ spin_unlock_irqrestore(&atchan->lock, flags);
+
+ return 0;
+}
+
+static int atc_resume(struct dma_chan *chan)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_dma *atdma = to_at_dma(chan->device);
+ int chan_id = atchan->chan_common.chan_id;
+ unsigned long flags;
+
+ LIST_HEAD(list);
+
+ dev_vdbg(chan2dev(chan), "%s\n", __func__);
+
+ if (!atc_chan_is_paused(atchan))
+ return 0;
+
+ spin_lock_irqsave(&atchan->lock, flags);
+
+ dma_writel(atdma, CHDR, AT_DMA_RES(chan_id));
+ clear_bit(ATC_IS_PAUSED, &atchan->status);
+
+ spin_unlock_irqrestore(&atchan->lock, flags);
+
+ return 0;
+}
+
+static int 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);
+ int chan_id = atchan->chan_common.chan_id;
+ struct at_desc *desc, *_desc;
+ unsigned long flags;
+
+ LIST_HEAD(list);
+
+ dev_vdbg(chan2dev(chan), "%s\n", __func__);
+
+ /*
+ * 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_irqsave(&atchan->lock, flags);
+
+ /* disabling channel: must also remove suspend state */
+ dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | 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);
+
+ /* Flush all pending and queued descriptors */
+ list_for_each_entry_safe(desc, _desc, &list, desc_node)
+ atc_chain_complete(atchan, desc);
+
+ clear_bit(ATC_IS_PAUSED, &atchan->status);
+ /* if channel dedicated to cyclic operations, free it */
+ clear_bit(ATC_IS_CYCLIC, &atchan->status);
+
+ spin_unlock_irqrestore(&atchan->lock, flags);
+
+ return 0;
+}
+
+/**
+ * atc_tx_status - poll for transaction completion
+ * @chan: DMA channel
+ * @cookie: transaction identifier to check status of
+ * @txstate: if not %NULL updated with transaction state
+ *
+ * If @txstate is passed in, upon return it 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_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ unsigned long flags;
+ enum dma_status ret;
+ int bytes = 0;
+
+ ret = dma_cookie_status(chan, cookie, txstate);
+ if (ret == DMA_COMPLETE)
+ return ret;
+ /*
+ * There's no point calculating the residue if there's
+ * no txstate to store the value.
+ */
+ if (!txstate)
+ return DMA_ERROR;
+
+ spin_lock_irqsave(&atchan->lock, flags);
+
+ /* Get number of bytes left in the active transactions */
+ bytes = atc_get_bytes_left(chan, cookie);
+
+ spin_unlock_irqrestore(&atchan->lock, flags);
+
+ if (unlikely(bytes < 0)) {
+ dev_vdbg(chan2dev(chan), "get residual bytes error\n");
+ return DMA_ERROR;
+ } else {
+ dma_set_residue(txstate, bytes);
+ }
+
+ dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d residue = %d\n",
+ ret, cookie, bytes);
+
+ 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);
+ unsigned long flags;
+
+ dev_vdbg(chan2dev(chan), "issue_pending\n");
+
+ /* Not needed for cyclic transfers */
+ if (atc_chan_is_cyclic(atchan))
+ return;
+
+ spin_lock_irqsave(&atchan->lock, flags);
+ atc_advance_work(atchan);
+ spin_unlock_irqrestore(&atchan->lock, flags);
+}
+
+/**
+ * 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;
+ unsigned long flags;
+ 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 instead 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_irqsave(&atchan->lock, flags);
+ atchan->descs_allocated = i;
+ list_splice(&tmp_list, &atchan->free_list);
+ dma_cookie_init(chan);
+ spin_unlock_irqrestore(&atchan->lock, flags);
+
+ /* 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;
+ atchan->status = 0;
+
+ dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
+}
+
+#ifdef CONFIG_OF
+static bool at_dma_filter(struct dma_chan *chan, void *slave)
+{
+ struct at_dma_slave *atslave = slave;
+
+ if (atslave->dma_dev == chan->device->dev) {
+ chan->private = atslave;
+ return true;
+ } else {
+ return false;
+ }
+}
+
+static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *of_dma)
+{
+ struct dma_chan *chan;
+ struct at_dma_chan *atchan;
+ struct at_dma_slave *atslave;
+ dma_cap_mask_t mask;
+ unsigned int per_id;
+ struct platform_device *dmac_pdev;
+
+ if (dma_spec->args_count != 2)
+ return NULL;
+
+ dmac_pdev = of_find_device_by_node(dma_spec->np);
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ atslave = devm_kzalloc(&dmac_pdev->dev, sizeof(*atslave), GFP_KERNEL);
+ if (!atslave)
+ return NULL;
+
+ atslave->cfg = ATC_DST_H2SEL_HW | ATC_SRC_H2SEL_HW;
+ /*
+ * We can fill both SRC_PER and DST_PER, one of these fields will be
+ * ignored depending on DMA transfer direction.
+ */
+ per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK;
+ atslave->cfg |= ATC_DST_PER_MSB(per_id) | ATC_DST_PER(per_id)
+ | ATC_SRC_PER_MSB(per_id) | ATC_SRC_PER(per_id);
+ /*
+ * We have to translate the value we get from the device tree since
+ * the half FIFO configuration value had to be 0 to keep backward
+ * compatibility.
+ */
+ switch (dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) {
+ case AT91_DMA_CFG_FIFOCFG_ALAP:
+ atslave->cfg |= ATC_FIFOCFG_LARGESTBURST;
+ break;
+ case AT91_DMA_CFG_FIFOCFG_ASAP:
+ atslave->cfg |= ATC_FIFOCFG_ENOUGHSPACE;
+ break;
+ case AT91_DMA_CFG_FIFOCFG_HALF:
+ default:
+ atslave->cfg |= ATC_FIFOCFG_HALFFIFO;
+ }
+ atslave->dma_dev = &dmac_pdev->dev;
+
+ chan = dma_request_channel(mask, at_dma_filter, atslave);
+ if (!chan)
+ return NULL;
+
+ atchan = to_at_dma_chan(chan);
+ atchan->per_if = dma_spec->args[0] & 0xff;
+ atchan->mem_if = (dma_spec->args[0] >> 16) & 0xff;
+
+ return chan;
+}
+#else
+static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *of_dma)
+{
+ return NULL;
+}
+#endif
+
+/*-- Module Management -----------------------------------------------*/
+
+/* cap_mask is a multi-u32 bitfield, fill it with proper C code. */
+static struct at_dma_platform_data at91sam9rl_config = {
+ .nr_channels = 2,
+};
+static struct at_dma_platform_data at91sam9g45_config = {
+ .nr_channels = 8,
+};
+
+#if defined(CONFIG_OF)
+static const struct of_device_id atmel_dma_dt_ids[] = {
+ {
+ .compatible = "atmel,at91sam9rl-dma",
+ .data = &at91sam9rl_config,
+ }, {
+ .compatible = "atmel,at91sam9g45-dma",
+ .data = &at91sam9g45_config,
+ }, {
+ /* sentinel */
+ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids);
+#endif
+
+static const struct platform_device_id atdma_devtypes[] = {
+ {
+ .name = "at91sam9rl_dma",
+ .driver_data = (unsigned long) &at91sam9rl_config,
+ }, {
+ .name = "at91sam9g45_dma",
+ .driver_data = (unsigned long) &at91sam9g45_config,
+ }, {
+ /* sentinel */
+ }
+};
+
+static inline const struct at_dma_platform_data * __init at_dma_get_driver_data(
+ struct platform_device *pdev)
+{
+ if (pdev->dev.of_node) {
+ const struct of_device_id *match;
+ match = of_match_node(atmel_dma_dt_ids, pdev->dev.of_node);
+ if (match == NULL)
+ return NULL;
+ return match->data;
+ }
+ return (struct at_dma_platform_data *)
+ platform_get_device_id(pdev)->driver_data;
+}
+
+/**
+ * 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 resource *io;
+ struct at_dma *atdma;
+ size_t size;
+ int irq;
+ int err;
+ int i;
+ const struct at_dma_platform_data *plat_dat;
+
+ /* setup platform data for each SoC */
+ dma_cap_set(DMA_MEMCPY, at91sam9rl_config.cap_mask);
+ dma_cap_set(DMA_SG, at91sam9rl_config.cap_mask);
+ dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask);
+ dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask);
+ dma_cap_set(DMA_SG, at91sam9g45_config.cap_mask);
+
+ /* get DMA parameters from controller type */
+ plat_dat = at_dma_get_driver_data(pdev);
+ if (!plat_dat)
+ return -ENODEV;
+
+ 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 += plat_dat->nr_channels * sizeof(struct at_dma_chan);
+ atdma = kzalloc(size, GFP_KERNEL);
+ if (!atdma)
+ return -ENOMEM;
+
+ /* discover transaction capabilities */
+ atdma->dma_common.cap_mask = plat_dat->cap_mask;
+ atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1;
+
+ size = resource_size(io);
+ 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;
+ }
+ err = clk_prepare_enable(atdma->clk);
+ if (err)
+ goto err_clk_prepare;
+
+ /* 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 < plat_dat->nr_channels; i++) {
+ struct at_dma_chan *atchan = &atdma->chan[i];
+
+ atchan->mem_if = AT_DMA_MEM_IF;
+ atchan->per_if = AT_DMA_PER_IF;
+ atchan->chan_common.device = &atdma->dma_common;
+ dma_cookie_init(&atchan->chan_common);
+ 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_chan_irq(atdma, i);
+ }
+
+ /* 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_tx_status = atc_tx_status;
+ 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;
+ /* controller can do slave DMA: can trigger cyclic transfers */
+ dma_cap_set(DMA_CYCLIC, atdma->dma_common.cap_mask);
+ atdma->dma_common.device_prep_dma_cyclic = atc_prep_dma_cyclic;
+ atdma->dma_common.device_config = atc_config;
+ atdma->dma_common.device_pause = atc_pause;
+ atdma->dma_common.device_resume = atc_resume;
+ atdma->dma_common.device_terminate_all = atc_terminate_all;
+ atdma->dma_common.src_addr_widths = ATC_DMA_BUSWIDTHS;
+ atdma->dma_common.dst_addr_widths = ATC_DMA_BUSWIDTHS;
+ atdma->dma_common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ atdma->dma_common.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+ }
+
+ if (dma_has_cap(DMA_SG, atdma->dma_common.cap_mask))
+ atdma->dma_common.device_prep_dma_sg = atc_prep_dma_sg;
+
+ dma_writel(atdma, EN, AT_DMA_ENABLE);
+
+ dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%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 " : "",
+ dma_has_cap(DMA_SG, atdma->dma_common.cap_mask) ? "sg-cpy " : "",
+ plat_dat->nr_channels);
+
+ dma_async_device_register(&atdma->dma_common);
+
+ /*
+ * Do not return an error if the dmac node is not present in order to
+ * not break the existing way of requesting channel with
+ * dma_request_channel().
+ */
+ if (pdev->dev.of_node) {
+ err = of_dma_controller_register(pdev->dev.of_node,
+ at_dma_xlate, atdma);
+ if (err) {
+ dev_err(&pdev->dev, "could not register of_dma_controller\n");
+ goto err_of_dma_controller_register;
+ }
+ }
+
+ return 0;
+
+err_of_dma_controller_register:
+ dma_async_device_unregister(&atdma->dma_common);
+ dma_pool_destroy(atdma->dma_desc_pool);
+err_pool_create:
+ free_irq(platform_get_irq(pdev, 0), atdma);
+err_irq:
+ clk_disable_unprepare(atdma->clk);
+err_clk_prepare:
+ 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 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);
+ 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_chan_irq(atdma, chan->chan_id);
+
+ tasklet_kill(&atchan->tasklet);
+ list_del(&chan->device_node);
+ }
+
+ clk_disable_unprepare(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, resource_size(io));
+
+ 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_unprepare(atdma->clk);
+}
+
+static int at_dma_prepare(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct at_dma *atdma = platform_get_drvdata(pdev);
+ struct dma_chan *chan, *_chan;
+
+ list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
+ device_node) {
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ /* wait for transaction completion (except in cyclic case) */
+ if (atc_chan_is_enabled(atchan) && !atc_chan_is_cyclic(atchan))
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+static void atc_suspend_cyclic(struct at_dma_chan *atchan)
+{
+ struct dma_chan *chan = &atchan->chan_common;
+
+ /* Channel should be paused by user
+ * do it anyway even if it is not done already */
+ if (!atc_chan_is_paused(atchan)) {
+ dev_warn(chan2dev(chan),
+ "cyclic channel not paused, should be done by channel user\n");
+ atc_pause(chan);
+ }
+
+ /* now preserve additional data for cyclic operations */
+ /* next descriptor address in the cyclic list */
+ atchan->save_dscr = channel_readl(atchan, DSCR);
+
+ vdbg_dump_regs(atchan);
+}
+
+static int at_dma_suspend_noirq(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct at_dma *atdma = platform_get_drvdata(pdev);
+ struct dma_chan *chan, *_chan;
+
+ /* preserve data */
+ list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
+ device_node) {
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+
+ if (atc_chan_is_cyclic(atchan))
+ atc_suspend_cyclic(atchan);
+ atchan->save_cfg = channel_readl(atchan, CFG);
+ }
+ atdma->save_imr = dma_readl(atdma, EBCIMR);
+
+ /* disable DMA controller */
+ at_dma_off(atdma);
+ clk_disable_unprepare(atdma->clk);
+ return 0;
+}
+
+static void atc_resume_cyclic(struct at_dma_chan *atchan)
+{
+ struct at_dma *atdma = to_at_dma(atchan->chan_common.device);
+
+ /* restore channel status for cyclic descriptors list:
+ * next descriptor in the cyclic list at the time of suspend */
+ channel_writel(atchan, SADDR, 0);
+ channel_writel(atchan, DADDR, 0);
+ channel_writel(atchan, CTRLA, 0);
+ channel_writel(atchan, CTRLB, 0);
+ channel_writel(atchan, DSCR, atchan->save_dscr);
+ dma_writel(atdma, CHER, atchan->mask);
+
+ /* channel pause status should be removed by channel user
+ * We cannot take the initiative to do it here */
+
+ vdbg_dump_regs(atchan);
+}
+
+static int at_dma_resume_noirq(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct at_dma *atdma = platform_get_drvdata(pdev);
+ struct dma_chan *chan, *_chan;
+
+ /* bring back DMA controller */
+ clk_prepare_enable(atdma->clk);
+ dma_writel(atdma, EN, AT_DMA_ENABLE);
+
+ /* clear any pending interrupt */
+ while (dma_readl(atdma, EBCISR))
+ cpu_relax();
+
+ /* restore saved data */
+ dma_writel(atdma, EBCIER, atdma->save_imr);
+ list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
+ device_node) {
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+
+ channel_writel(atchan, CFG, atchan->save_cfg);
+ if (atc_chan_is_cyclic(atchan))
+ atc_resume_cyclic(atchan);
+ }
+ return 0;
+}
+
+static const struct dev_pm_ops at_dma_dev_pm_ops = {
+ .prepare = at_dma_prepare,
+ .suspend_noirq = at_dma_suspend_noirq,
+ .resume_noirq = at_dma_resume_noirq,
+};
+
+static struct platform_driver at_dma_driver = {
+ .remove = at_dma_remove,
+ .shutdown = at_dma_shutdown,
+ .id_table = atdma_devtypes,
+ .driver = {
+ .name = "at_hdmac",
+ .pm = &at_dma_dev_pm_ops,
+ .of_match_table = of_match_ptr(atmel_dma_dt_ids),
+ },
+};
+
+static int __init at_dma_init(void)
+{
+ return platform_driver_probe(&at_dma_driver, at_dma_probe);
+}
+subsys_initcall(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");
Code Review / kvmfornfv.git / blobdiff