/*
* Freescale MPC85xx, MPC83xx DMA Engine support
*
- * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
+ * Copyright (C) 2007-2010 Freescale Semiconductor, Inc. All rights reserved.
*
* Author:
* Zhang Wei <wei.zhang@freescale.com>, Jul 2007
* Description:
* DMA engine driver for Freescale MPC8540 DMA controller, which is
* also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc.
- * The support for MPC8349 DMA contorller is also added.
+ * The support for MPC8349 DMA controller is also added.
*
* This driver instructs the DMA controller to issue the PCI Read Multiple
* command for PCI read operations, instead of using the default PCI Read Line
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
+#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/dmaengine.h>
#include <linux/delay.h>
#include <linux/dmapool.h>
#include <linux/of_platform.h>
-#include <asm/fsldma.h>
#include "fsldma.h"
-static void dma_init(struct fsldma_chan *chan)
-{
- /* Reset the channel */
- DMA_OUT(chan, &chan->regs->mr, 0, 32);
+#define chan_dbg(chan, fmt, arg...) \
+ dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
+#define chan_err(chan, fmt, arg...) \
+ dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
- switch (chan->feature & FSL_DMA_IP_MASK) {
- case FSL_DMA_IP_85XX:
- /* Set the channel to below modes:
- * EIE - Error interrupt enable
- * EOSIE - End of segments interrupt enable (basic mode)
- * EOLNIE - End of links interrupt enable
- */
- DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EIE
- | FSL_DMA_MR_EOLNIE | FSL_DMA_MR_EOSIE, 32);
- break;
- case FSL_DMA_IP_83XX:
- /* Set the channel to below modes:
- * EOTIE - End-of-transfer interrupt enable
- * PRC_RM - PCI read multiple
- */
- DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EOTIE
- | FSL_DMA_MR_PRC_RM, 32);
- break;
- }
-}
+static const char msg_ld_oom[] = "No free memory for link descriptor";
+
+/*
+ * Register Helpers
+ */
static void set_sr(struct fsldma_chan *chan, u32 val)
{
return DMA_IN(chan, &chan->regs->sr, 32);
}
+static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
+{
+ DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
+}
+
+static dma_addr_t get_cdar(struct fsldma_chan *chan)
+{
+ return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
+}
+
+static u32 get_bcr(struct fsldma_chan *chan)
+{
+ return DMA_IN(chan, &chan->regs->bcr, 32);
+}
+
+/*
+ * Descriptor Helpers
+ */
+
static void set_desc_cnt(struct fsldma_chan *chan,
struct fsl_dma_ld_hw *hw, u32 count)
{
hw->count = CPU_TO_DMA(chan, count, 32);
}
+static u32 get_desc_cnt(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
+{
+ return DMA_TO_CPU(chan, desc->hw.count, 32);
+}
+
static void set_desc_src(struct fsldma_chan *chan,
- struct fsl_dma_ld_hw *hw, dma_addr_t src)
+ struct fsl_dma_ld_hw *hw, dma_addr_t src)
{
u64 snoop_bits;
hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);
}
+static dma_addr_t get_desc_src(struct fsldma_chan *chan,
+ struct fsl_desc_sw *desc)
+{
+ u64 snoop_bits;
+
+ snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
+ ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
+ return DMA_TO_CPU(chan, desc->hw.src_addr, 64) & ~snoop_bits;
+}
+
static void set_desc_dst(struct fsldma_chan *chan,
- struct fsl_dma_ld_hw *hw, dma_addr_t dst)
+ struct fsl_dma_ld_hw *hw, dma_addr_t dst)
{
u64 snoop_bits;
hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);
}
+static dma_addr_t get_desc_dst(struct fsldma_chan *chan,
+ struct fsl_desc_sw *desc)
+{
+ u64 snoop_bits;
+
+ snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
+ ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
+ return DMA_TO_CPU(chan, desc->hw.dst_addr, 64) & ~snoop_bits;
+}
+
static void set_desc_next(struct fsldma_chan *chan,
- struct fsl_dma_ld_hw *hw, dma_addr_t next)
+ struct fsl_dma_ld_hw *hw, dma_addr_t next)
{
u64 snoop_bits;
hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64);
}
-static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
+static void set_ld_eol(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
{
- DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
-}
+ u64 snoop_bits;
-static dma_addr_t get_cdar(struct fsldma_chan *chan)
-{
- return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
-}
+ snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
+ ? FSL_DMA_SNEN : 0;
-static dma_addr_t get_ndar(struct fsldma_chan *chan)
-{
- return DMA_IN(chan, &chan->regs->ndar, 64);
+ desc->hw.next_ln_addr = CPU_TO_DMA(chan,
+ DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
+ | snoop_bits, 64);
}
-static u32 get_bcr(struct fsldma_chan *chan)
+/*
+ * DMA Engine Hardware Control Helpers
+ */
+
+static void dma_init(struct fsldma_chan *chan)
{
- return DMA_IN(chan, &chan->regs->bcr, 32);
+ /* Reset the channel */
+ DMA_OUT(chan, &chan->regs->mr, 0, 32);
+
+ switch (chan->feature & FSL_DMA_IP_MASK) {
+ case FSL_DMA_IP_85XX:
+ /* Set the channel to below modes:
+ * EIE - Error interrupt enable
+ * EOLNIE - End of links interrupt enable
+ * BWC - Bandwidth sharing among channels
+ */
+ DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_BWC
+ | FSL_DMA_MR_EIE | FSL_DMA_MR_EOLNIE, 32);
+ break;
+ case FSL_DMA_IP_83XX:
+ /* Set the channel to below modes:
+ * EOTIE - End-of-transfer interrupt enable
+ * PRC_RM - PCI read multiple
+ */
+ DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EOTIE
+ | FSL_DMA_MR_PRC_RM, 32);
+ break;
+ }
}
static int dma_is_idle(struct fsldma_chan *chan)
return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
}
+/*
+ * Start the DMA controller
+ *
+ * Preconditions:
+ * - the CDAR register must point to the start descriptor
+ * - the MRn[CS] bit must be cleared
+ */
static void dma_start(struct fsldma_chan *chan)
{
u32 mode;
mode = DMA_IN(chan, &chan->regs->mr, 32);
- if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
- if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
- DMA_OUT(chan, &chan->regs->bcr, 0, 32);
- mode |= FSL_DMA_MR_EMP_EN;
- } else {
- mode &= ~FSL_DMA_MR_EMP_EN;
- }
+ if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
+ DMA_OUT(chan, &chan->regs->bcr, 0, 32);
+ mode |= FSL_DMA_MR_EMP_EN;
+ } else {
+ mode &= ~FSL_DMA_MR_EMP_EN;
}
- if (chan->feature & FSL_DMA_CHAN_START_EXT)
+ if (chan->feature & FSL_DMA_CHAN_START_EXT) {
mode |= FSL_DMA_MR_EMS_EN;
- else
+ } else {
+ mode &= ~FSL_DMA_MR_EMS_EN;
mode |= FSL_DMA_MR_CS;
+ }
DMA_OUT(chan, &chan->regs->mr, mode, 32);
}
u32 mode;
int i;
+ /* read the mode register */
mode = DMA_IN(chan, &chan->regs->mr, 32);
- mode |= FSL_DMA_MR_CA;
- DMA_OUT(chan, &chan->regs->mr, mode, 32);
- mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA);
+ /*
+ * The 85xx controller supports channel abort, which will stop
+ * the current transfer. On 83xx, this bit is the transfer error
+ * mask bit, which should not be changed.
+ */
+ if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
+ mode |= FSL_DMA_MR_CA;
+ DMA_OUT(chan, &chan->regs->mr, mode, 32);
+
+ mode &= ~FSL_DMA_MR_CA;
+ }
+
+ /* stop the DMA controller */
+ mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN);
DMA_OUT(chan, &chan->regs->mr, mode, 32);
+ /* wait for the DMA controller to become idle */
for (i = 0; i < 100; i++) {
if (dma_is_idle(chan))
return;
}
if (!dma_is_idle(chan))
- dev_err(chan->dev, "DMA halt timeout!\n");
-}
-
-static void set_ld_eol(struct fsldma_chan *chan,
- struct fsl_desc_sw *desc)
-{
- u64 snoop_bits;
-
- snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
- ? FSL_DMA_SNEN : 0;
-
- desc->hw.next_ln_addr = CPU_TO_DMA(chan,
- DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
- | snoop_bits, 64);
+ chan_err(chan, "DMA halt timeout!\n");
}
/**
chan->feature &= ~FSL_DMA_CHAN_START_EXT;
}
-static void append_ld_queue(struct fsldma_chan *chan,
- struct fsl_desc_sw *desc)
+static void append_ld_queue(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
{
struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev);
cookie = chan->common.cookie;
list_for_each_entry(child, &desc->tx_list, node) {
cookie++;
- if (cookie < 0)
- cookie = 1;
+ if (cookie < DMA_MIN_COOKIE)
+ cookie = DMA_MIN_COOKIE;
- desc->async_tx.cookie = cookie;
+ child->async_tx.cookie = cookie;
}
chan->common.cookie = cookie;
*
* Return - The descriptor allocated. NULL for failed.
*/
-static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
- struct fsldma_chan *chan)
+static struct fsl_desc_sw *fsl_dma_alloc_descriptor(struct fsldma_chan *chan)
{
struct fsl_desc_sw *desc;
dma_addr_t pdesc;
desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
if (!desc) {
- dev_dbg(chan->dev, "out of memory for link desc\n");
+ chan_dbg(chan, "out of memory for link descriptor\n");
return NULL;
}
desc->async_tx.tx_submit = fsl_dma_tx_submit;
desc->async_tx.phys = pdesc;
+#ifdef FSL_DMA_LD_DEBUG
+ chan_dbg(chan, "LD %p allocated\n", desc);
+#endif
+
return desc;
}
-
/**
* fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
* @chan : Freescale DMA channel
* We need the descriptor to be aligned to 32bytes
* for meeting FSL DMA specification requirement.
*/
- chan->desc_pool = dma_pool_create("fsl_dma_engine_desc_pool",
- chan->dev,
+ chan->desc_pool = dma_pool_create(chan->name, chan->dev,
sizeof(struct fsl_desc_sw),
__alignof__(struct fsl_desc_sw), 0);
if (!chan->desc_pool) {
- dev_err(chan->dev, "unable to allocate channel %d "
- "descriptor pool\n", chan->id);
+ chan_err(chan, "unable to allocate descriptor pool\n");
return -ENOMEM;
}
list_for_each_entry_safe(desc, _desc, list, node) {
list_del(&desc->node);
+#ifdef FSL_DMA_LD_DEBUG
+ chan_dbg(chan, "LD %p free\n", desc);
+#endif
dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
}
}
list_for_each_entry_safe_reverse(desc, _desc, list, node) {
list_del(&desc->node);
+#ifdef FSL_DMA_LD_DEBUG
+ chan_dbg(chan, "LD %p free\n", desc);
+#endif
dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
}
}
struct fsldma_chan *chan = to_fsl_chan(dchan);
unsigned long flags;
- dev_dbg(chan->dev, "Free all channel resources.\n");
+ chan_dbg(chan, "free all channel resources\n");
spin_lock_irqsave(&chan->desc_lock, flags);
fsldma_free_desc_list(chan, &chan->ld_pending);
fsldma_free_desc_list(chan, &chan->ld_running);
new = fsl_dma_alloc_descriptor(chan);
if (!new) {
- dev_err(chan->dev, "No free memory for link descriptor\n");
+ chan_err(chan, "%s\n", msg_ld_oom);
return NULL;
}
/* Insert the link descriptor to the LD ring */
list_add_tail(&new->node, &new->tx_list);
- /* Set End-of-link to the last link descriptor of new list*/
+ /* Set End-of-link to the last link descriptor of new list */
set_ld_eol(chan, new);
return &new->async_tx;
}
-static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
- struct dma_chan *dchan, dma_addr_t dma_dst, dma_addr_t dma_src,
+static struct dma_async_tx_descriptor *
+fsl_dma_prep_memcpy(struct dma_chan *dchan,
+ dma_addr_t dma_dst, dma_addr_t dma_src,
size_t len, unsigned long flags)
{
struct fsldma_chan *chan;
/* Allocate the link descriptor from DMA pool */
new = fsl_dma_alloc_descriptor(chan);
if (!new) {
- dev_err(chan->dev,
- "No free memory for link descriptor\n");
+ chan_err(chan, "%s\n", msg_ld_oom);
goto fail;
}
-#ifdef FSL_DMA_LD_DEBUG
- dev_dbg(chan->dev, "new link desc alloc %p\n", new);
-#endif
copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
new->async_tx.flags = flags; /* client is in control of this ack */
new->async_tx.cookie = -EBUSY;
- /* Set End-of-link to the last link descriptor of new list*/
+ /* Set End-of-link to the last link descriptor of new list */
set_ld_eol(chan, new);
return &first->async_tx;
return NULL;
}
-/**
- * fsl_dma_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: DMAEngine flags
- *
- * Prepare a set of descriptors for a DMA_SLAVE transaction. Following the
- * DMA_SLAVE API, this gets the device-specific information from the
- * chan->private variable.
- */
-static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
- struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
- enum dma_data_direction direction, unsigned long flags)
+static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan,
+ struct scatterlist *dst_sg, unsigned int dst_nents,
+ struct scatterlist *src_sg, unsigned int src_nents,
+ unsigned long flags)
{
- struct fsldma_chan *chan;
struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
- struct fsl_dma_slave *slave;
- size_t copy;
-
- int i;
- struct scatterlist *sg;
- size_t sg_used;
- size_t hw_used;
- struct fsl_dma_hw_addr *hw;
- dma_addr_t dma_dst, dma_src;
+ struct fsldma_chan *chan = to_fsl_chan(dchan);
+ size_t dst_avail, src_avail;
+ dma_addr_t dst, src;
+ size_t len;
- if (!dchan)
+ /* basic sanity checks */
+ if (dst_nents == 0 || src_nents == 0)
return NULL;
- if (!dchan->private)
+ if (dst_sg == NULL || src_sg == NULL)
return NULL;
- chan = to_fsl_chan(dchan);
- slave = dchan->private;
+ /*
+ * TODO: should we check that both scatterlists have the same
+ * TODO: number of bytes in total? Is that really an error?
+ */
- if (list_empty(&slave->addresses))
- return NULL;
+ /* get prepared for the loop */
+ dst_avail = sg_dma_len(dst_sg);
+ src_avail = sg_dma_len(src_sg);
- hw = list_first_entry(&slave->addresses, struct fsl_dma_hw_addr, entry);
- hw_used = 0;
+ /* run until we are out of scatterlist entries */
+ while (true) {
- /*
- * Build the hardware transaction to copy from the scatterlist to
- * the hardware, or from the hardware to the scatterlist
- *
- * If you are copying from the hardware to the scatterlist and it
- * takes two hardware entries to fill an entire page, then both
- * hardware entries will be coalesced into the same page
- *
- * If you are copying from the scatterlist to the hardware and a
- * single page can fill two hardware entries, then the data will
- * be read out of the page into the first hardware entry, and so on
- */
- for_each_sg(sgl, sg, sg_len, i) {
- sg_used = 0;
-
- /* Loop until the entire scatterlist entry is used */
- while (sg_used < sg_dma_len(sg)) {
-
- /*
- * If we've used up the current hardware address/length
- * pair, we need to load a new one
- *
- * This is done in a while loop so that descriptors with
- * length == 0 will be skipped
- */
- while (hw_used >= hw->length) {
-
- /*
- * If the current hardware entry is the last
- * entry in the list, we're finished
- */
- if (list_is_last(&hw->entry, &slave->addresses))
- goto finished;
-
- /* Get the next hardware address/length pair */
- hw = list_entry(hw->entry.next,
- struct fsl_dma_hw_addr, entry);
- hw_used = 0;
- }
-
- /* Allocate the link descriptor from DMA pool */
- new = fsl_dma_alloc_descriptor(chan);
- if (!new) {
- dev_err(chan->dev, "No free memory for "
- "link descriptor\n");
- goto fail;
- }
-#ifdef FSL_DMA_LD_DEBUG
- dev_dbg(chan->dev, "new link desc alloc %p\n", new);
-#endif
+ /* create the largest transaction possible */
+ len = min_t(size_t, src_avail, dst_avail);
+ len = min_t(size_t, len, FSL_DMA_BCR_MAX_CNT);
+ if (len == 0)
+ goto fetch;
+
+ dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
+ src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
- /*
- * Calculate the maximum number of bytes to transfer,
- * making sure it is less than the DMA controller limit
- */
- copy = min_t(size_t, sg_dma_len(sg) - sg_used,
- hw->length - hw_used);
- copy = min_t(size_t, copy, FSL_DMA_BCR_MAX_CNT);
-
- /*
- * DMA_FROM_DEVICE
- * from the hardware to the scatterlist
- *
- * DMA_TO_DEVICE
- * from the scatterlist to the hardware
- */
- if (direction == DMA_FROM_DEVICE) {
- dma_src = hw->address + hw_used;
- dma_dst = sg_dma_address(sg) + sg_used;
- } else {
- dma_src = sg_dma_address(sg) + sg_used;
- dma_dst = hw->address + hw_used;
- }
-
- /* Fill in the descriptor */
- set_desc_cnt(chan, &new->hw, copy);
- set_desc_src(chan, &new->hw, dma_src);
- set_desc_dst(chan, &new->hw, dma_dst);
-
- /*
- * If this is not the first descriptor, chain the
- * current descriptor after the previous descriptor
- */
- if (!first) {
- first = new;
- } else {
- set_desc_next(chan, &prev->hw,
- new->async_tx.phys);
- }
-
- new->async_tx.cookie = 0;
- async_tx_ack(&new->async_tx);
-
- prev = new;
- sg_used += copy;
- hw_used += copy;
-
- /* Insert the link descriptor into the LD ring */
- list_add_tail(&new->node, &first->tx_list);
+ /* allocate and populate the descriptor */
+ new = fsl_dma_alloc_descriptor(chan);
+ if (!new) {
+ chan_err(chan, "%s\n", msg_ld_oom);
+ goto fail;
}
- }
-finished:
+ set_desc_cnt(chan, &new->hw, len);
+ set_desc_src(chan, &new->hw, src);
+ set_desc_dst(chan, &new->hw, dst);
- /* All of the hardware address/length pairs had length == 0 */
- if (!first || !new)
- return NULL;
+ if (!first)
+ first = new;
+ else
+ set_desc_next(chan, &prev->hw, new->async_tx.phys);
- new->async_tx.flags = flags;
- new->async_tx.cookie = -EBUSY;
+ new->async_tx.cookie = 0;
+ async_tx_ack(&new->async_tx);
+ prev = new;
- /* Set End-of-link to the last link descriptor of new list */
- set_ld_eol(chan, new);
+ /* Insert the link descriptor to the LD ring */
+ list_add_tail(&new->node, &first->tx_list);
+
+ /* update metadata */
+ dst_avail -= len;
+ src_avail -= len;
- /* Enable extra controller features */
- if (chan->set_src_loop_size)
- chan->set_src_loop_size(chan, slave->src_loop_size);
+fetch:
+ /* fetch the next dst scatterlist entry */
+ if (dst_avail == 0) {
- if (chan->set_dst_loop_size)
- chan->set_dst_loop_size(chan, slave->dst_loop_size);
+ /* no more entries: we're done */
+ if (dst_nents == 0)
+ break;
- if (chan->toggle_ext_start)
- chan->toggle_ext_start(chan, slave->external_start);
+ /* fetch the next entry: if there are no more: done */
+ dst_sg = sg_next(dst_sg);
+ if (dst_sg == NULL)
+ break;
- if (chan->toggle_ext_pause)
- chan->toggle_ext_pause(chan, slave->external_pause);
+ dst_nents--;
+ dst_avail = sg_dma_len(dst_sg);
+ }
- if (chan->set_request_count)
- chan->set_request_count(chan, slave->request_count);
+ /* fetch the next src scatterlist entry */
+ if (src_avail == 0) {
+
+ /* no more entries: we're done */
+ if (src_nents == 0)
+ break;
+
+ /* fetch the next entry: if there are no more: done */
+ src_sg = sg_next(src_sg);
+ if (src_sg == NULL)
+ break;
+
+ src_nents--;
+ src_avail = sg_dma_len(src_sg);
+ }
+ }
+
+ new->async_tx.flags = flags; /* client is in control of this ack */
+ new->async_tx.cookie = -EBUSY;
+
+ /* Set End-of-link to the last link descriptor of new list */
+ set_ld_eol(chan, new);
return &first->async_tx;
fail:
- /* If first was not set, then we failed to allocate the very first
- * descriptor, and we're done */
if (!first)
return NULL;
+ fsldma_free_desc_list_reverse(chan, &first->tx_list);
+ return NULL;
+}
+
+/**
+ * fsl_dma_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: DMAEngine flags
+ *
+ * Prepare a set of descriptors for a DMA_SLAVE transaction. Following the
+ * DMA_SLAVE API, this gets the device-specific information from the
+ * chan->private variable.
+ */
+static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
+ struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
+ enum dma_data_direction direction, unsigned long flags)
+{
/*
- * First is set, so all of the descriptors we allocated have been added
- * to first->tx_list, INCLUDING "first" itself. Therefore we
- * must traverse the list backwards freeing each descriptor in turn
+ * This operation is not supported on the Freescale DMA controller
*
- * We're re-using variables for the loop, oh well
+ * However, we need to provide the function pointer to allow the
+ * device_control() method to work.
*/
- fsldma_free_desc_list_reverse(chan, &first->tx_list);
return NULL;
}
-static void fsl_dma_device_terminate_all(struct dma_chan *dchan)
+static int fsl_dma_device_control(struct dma_chan *dchan,
+ enum dma_ctrl_cmd cmd, unsigned long arg)
{
+ struct dma_slave_config *config;
struct fsldma_chan *chan;
unsigned long flags;
+ int size;
if (!dchan)
- return;
+ return -EINVAL;
chan = to_fsl_chan(dchan);
- /* Halt the DMA engine */
- dma_halt(chan);
+ switch (cmd) {
+ case DMA_TERMINATE_ALL:
+ spin_lock_irqsave(&chan->desc_lock, flags);
- spin_lock_irqsave(&chan->desc_lock, flags);
+ /* Halt the DMA engine */
+ dma_halt(chan);
- /* Remove and free all of the descriptors in the LD queue */
- fsldma_free_desc_list(chan, &chan->ld_pending);
- fsldma_free_desc_list(chan, &chan->ld_running);
+ /* Remove and free all of the descriptors in the LD queue */
+ fsldma_free_desc_list(chan, &chan->ld_pending);
+ fsldma_free_desc_list(chan, &chan->ld_running);
+ chan->idle = true;
- spin_unlock_irqrestore(&chan->desc_lock, flags);
-}
+ spin_unlock_irqrestore(&chan->desc_lock, flags);
+ return 0;
-/**
- * fsl_dma_update_completed_cookie - Update the completed cookie.
- * @chan : Freescale DMA channel
- *
- * CONTEXT: hardirq
- */
-static void fsl_dma_update_completed_cookie(struct fsldma_chan *chan)
-{
- struct fsl_desc_sw *desc;
- unsigned long flags;
- dma_cookie_t cookie;
+ case DMA_SLAVE_CONFIG:
+ config = (struct dma_slave_config *)arg;
- spin_lock_irqsave(&chan->desc_lock, flags);
+ /* make sure the channel supports setting burst size */
+ if (!chan->set_request_count)
+ return -ENXIO;
- if (list_empty(&chan->ld_running)) {
- dev_dbg(chan->dev, "no running descriptors\n");
- goto out_unlock;
- }
+ /* we set the controller burst size depending on direction */
+ if (config->direction == DMA_TO_DEVICE)
+ size = config->dst_addr_width * config->dst_maxburst;
+ else
+ size = config->src_addr_width * config->src_maxburst;
- /* Get the last descriptor, update the cookie to that */
- desc = to_fsl_desc(chan->ld_running.prev);
- if (dma_is_idle(chan))
- cookie = desc->async_tx.cookie;
- else
- cookie = desc->async_tx.cookie - 1;
+ chan->set_request_count(chan, size);
+ return 0;
- chan->completed_cookie = cookie;
+ case FSLDMA_EXTERNAL_START:
-out_unlock:
- spin_unlock_irqrestore(&chan->desc_lock, flags);
-}
+ /* make sure the channel supports external start */
+ if (!chan->toggle_ext_start)
+ return -ENXIO;
-/**
- * fsldma_desc_status - Check the status of a descriptor
- * @chan: Freescale DMA channel
- * @desc: DMA SW descriptor
- *
- * This function will return the status of the given descriptor
- */
-static enum dma_status fsldma_desc_status(struct fsldma_chan *chan,
- struct fsl_desc_sw *desc)
-{
- return dma_async_is_complete(desc->async_tx.cookie,
- chan->completed_cookie,
- chan->common.cookie);
+ chan->toggle_ext_start(chan, arg);
+ return 0;
+
+ default:
+ return -ENXIO;
+ }
+
+ return 0;
}
/**
- * fsl_chan_ld_cleanup - Clean up link descriptors
- * @chan : Freescale DMA channel
+ * fsldma_cleanup_descriptor - cleanup and free a single link descriptor
+ * @chan: Freescale DMA channel
+ * @desc: descriptor to cleanup and free
*
- * This function clean up the ld_queue of DMA channel.
+ * This function is used on a descriptor which has been executed by the DMA
+ * controller. It will run any callbacks, submit any dependencies, and then
+ * free the descriptor.
*/
-static void fsl_chan_ld_cleanup(struct fsldma_chan *chan)
+static void fsldma_cleanup_descriptor(struct fsldma_chan *chan,
+ struct fsl_desc_sw *desc)
{
- struct fsl_desc_sw *desc, *_desc;
- unsigned long flags;
-
- spin_lock_irqsave(&chan->desc_lock, flags);
-
- dev_dbg(chan->dev, "chan completed_cookie = %d\n", chan->completed_cookie);
- list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
- dma_async_tx_callback callback;
- void *callback_param;
-
- if (fsldma_desc_status(chan, desc) == DMA_IN_PROGRESS)
- break;
+ struct dma_async_tx_descriptor *txd = &desc->async_tx;
+ struct device *dev = chan->common.device->dev;
+ dma_addr_t src = get_desc_src(chan, desc);
+ dma_addr_t dst = get_desc_dst(chan, desc);
+ u32 len = get_desc_cnt(chan, desc);
+
+ /* Run the link descriptor callback function */
+ if (txd->callback) {
+#ifdef FSL_DMA_LD_DEBUG
+ chan_dbg(chan, "LD %p callback\n", desc);
+#endif
+ txd->callback(txd->callback_param);
+ }
- /* Remove from the list of running transactions */
- list_del(&desc->node);
+ /* Run any dependencies */
+ dma_run_dependencies(txd);
- /* Run the link descriptor callback function */
- callback = desc->async_tx.callback;
- callback_param = desc->async_tx.callback_param;
- if (callback) {
- spin_unlock_irqrestore(&chan->desc_lock, flags);
- dev_dbg(chan->dev, "LD %p callback\n", desc);
- callback(callback_param);
- spin_lock_irqsave(&chan->desc_lock, flags);
- }
+ /* Unmap the dst buffer, if requested */
+ if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
+ if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
+ dma_unmap_single(dev, dst, len, DMA_FROM_DEVICE);
+ else
+ dma_unmap_page(dev, dst, len, DMA_FROM_DEVICE);
+ }
- /* Run any dependencies, then free the descriptor */
- dma_run_dependencies(&desc->async_tx);
- dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
+ /* Unmap the src buffer, if requested */
+ if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
+ if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
+ dma_unmap_single(dev, src, len, DMA_TO_DEVICE);
+ else
+ dma_unmap_page(dev, src, len, DMA_TO_DEVICE);
}
- spin_unlock_irqrestore(&chan->desc_lock, flags);
+#ifdef FSL_DMA_LD_DEBUG
+ chan_dbg(chan, "LD %p free\n", desc);
+#endif
+ dma_pool_free(chan->desc_pool, desc, txd->phys);
}
/**
* fsl_chan_xfer_ld_queue - transfer any pending transactions
* @chan : Freescale DMA channel
*
- * This will make sure that any pending transactions will be run.
- * If the DMA controller is idle, it will be started. Otherwise,
- * the DMA controller's interrupt handler will start any pending
- * transactions when it becomes idle.
+ * HARDWARE STATE: idle
+ * LOCKING: must hold chan->desc_lock
*/
static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
{
struct fsl_desc_sw *desc;
- unsigned long flags;
-
- spin_lock_irqsave(&chan->desc_lock, flags);
/*
* If the list of pending descriptors is empty, then we
* don't need to do any work at all
*/
if (list_empty(&chan->ld_pending)) {
- dev_dbg(chan->dev, "no pending LDs\n");
- goto out_unlock;
+ chan_dbg(chan, "no pending LDs\n");
+ return;
}
/*
- * The DMA controller is not idle, which means the interrupt
- * handler will start any queued transactions when it runs
- * at the end of the current transaction
+ * The DMA controller is not idle, which means that the interrupt
+ * handler will start any queued transactions when it runs after
+ * this transaction finishes
*/
- if (!dma_is_idle(chan)) {
- dev_dbg(chan->dev, "DMA controller still busy\n");
- goto out_unlock;
+ if (!chan->idle) {
+ chan_dbg(chan, "DMA controller still busy\n");
+ return;
}
- /*
- * TODO:
- * make sure the dma_halt() function really un-wedges the
- * controller as much as possible
- */
- dma_halt(chan);
-
/*
* If there are some link descriptors which have not been
* transferred, we need to start the controller
* Move all elements from the queue of pending transactions
* onto the list of running transactions
*/
+ chan_dbg(chan, "idle, starting controller\n");
desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
+ /*
+ * The 85xx DMA controller doesn't clear the channel start bit
+ * automatically at the end of a transfer. Therefore we must clear
+ * it in software before starting the transfer.
+ */
+ if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
+ u32 mode;
+
+ mode = DMA_IN(chan, &chan->regs->mr, 32);
+ mode &= ~FSL_DMA_MR_CS;
+ DMA_OUT(chan, &chan->regs->mr, mode, 32);
+ }
+
/*
* Program the descriptor's address into the DMA controller,
* then start the DMA transaction
*/
set_cdar(chan, desc->async_tx.phys);
- dma_start(chan);
+ get_cdar(chan);
-out_unlock:
- spin_unlock_irqrestore(&chan->desc_lock, flags);
+ dma_start(chan);
+ chan->idle = false;
}
/**
static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
{
struct fsldma_chan *chan = to_fsl_chan(dchan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->desc_lock, flags);
fsl_chan_xfer_ld_queue(chan);
+ spin_unlock_irqrestore(&chan->desc_lock, flags);
}
/**
- * fsl_dma_is_complete - Determine the DMA status
+ * fsl_tx_status - Determine the DMA status
* @chan : Freescale DMA channel
*/
-static enum dma_status fsl_dma_is_complete(struct dma_chan *dchan,
+static enum dma_status fsl_tx_status(struct dma_chan *dchan,
dma_cookie_t cookie,
- dma_cookie_t *done,
- dma_cookie_t *used)
+ struct dma_tx_state *txstate)
{
struct fsldma_chan *chan = to_fsl_chan(dchan);
- dma_cookie_t last_used;
dma_cookie_t last_complete;
+ dma_cookie_t last_used;
+ unsigned long flags;
- fsl_chan_ld_cleanup(chan);
+ spin_lock_irqsave(&chan->desc_lock, flags);
- last_used = dchan->cookie;
last_complete = chan->completed_cookie;
+ last_used = dchan->cookie;
- if (done)
- *done = last_complete;
-
- if (used)
- *used = last_used;
+ spin_unlock_irqrestore(&chan->desc_lock, flags);
+ dma_set_tx_state(txstate, last_complete, last_used, 0);
return dma_async_is_complete(cookie, last_complete, last_used);
}
static irqreturn_t fsldma_chan_irq(int irq, void *data)
{
struct fsldma_chan *chan = data;
- int update_cookie = 0;
- int xfer_ld_q = 0;
u32 stat;
/* save and clear the status register */
stat = get_sr(chan);
set_sr(chan, stat);
- dev_dbg(chan->dev, "irq: channel %d, stat = 0x%x\n", chan->id, stat);
+ chan_dbg(chan, "irq: stat = 0x%x\n", stat);
+ /* check that this was really our device */
stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
if (!stat)
return IRQ_NONE;
if (stat & FSL_DMA_SR_TE)
- dev_err(chan->dev, "Transfer Error!\n");
+ chan_err(chan, "Transfer Error!\n");
/*
* Programming Error
* triger a PE interrupt.
*/
if (stat & FSL_DMA_SR_PE) {
- dev_dbg(chan->dev, "irq: Programming Error INT\n");
- if (get_bcr(chan) == 0) {
- /* BCR register is 0, this is a DMA_INTERRUPT async_tx.
- * Now, update the completed cookie, and continue the
- * next uncompleted transfer.
- */
- update_cookie = 1;
- xfer_ld_q = 1;
- }
+ chan_dbg(chan, "irq: Programming Error INT\n");
stat &= ~FSL_DMA_SR_PE;
- }
-
- /*
- * If the link descriptor segment transfer finishes,
- * we will recycle the used descriptor.
- */
- if (stat & FSL_DMA_SR_EOSI) {
- dev_dbg(chan->dev, "irq: End-of-segments INT\n");
- dev_dbg(chan->dev, "irq: clndar 0x%llx, nlndar 0x%llx\n",
- (unsigned long long)get_cdar(chan),
- (unsigned long long)get_ndar(chan));
- stat &= ~FSL_DMA_SR_EOSI;
- update_cookie = 1;
+ if (get_bcr(chan) != 0)
+ chan_err(chan, "Programming Error!\n");
}
/*
* and start the next transfer if it exist.
*/
if (stat & FSL_DMA_SR_EOCDI) {
- dev_dbg(chan->dev, "irq: End-of-Chain link INT\n");
+ chan_dbg(chan, "irq: End-of-Chain link INT\n");
stat &= ~FSL_DMA_SR_EOCDI;
- update_cookie = 1;
- xfer_ld_q = 1;
}
/*
* prepare next transfer.
*/
if (stat & FSL_DMA_SR_EOLNI) {
- dev_dbg(chan->dev, "irq: End-of-link INT\n");
+ chan_dbg(chan, "irq: End-of-link INT\n");
stat &= ~FSL_DMA_SR_EOLNI;
- xfer_ld_q = 1;
}
- if (update_cookie)
- fsl_dma_update_completed_cookie(chan);
- if (xfer_ld_q)
- fsl_chan_xfer_ld_queue(chan);
+ /* check that the DMA controller is really idle */
+ if (!dma_is_idle(chan))
+ chan_err(chan, "irq: controller not idle!\n");
+
+ /* check that we handled all of the bits */
if (stat)
- dev_dbg(chan->dev, "irq: unhandled sr 0x%02x\n", stat);
+ chan_err(chan, "irq: unhandled sr 0x%08x\n", stat);
- dev_dbg(chan->dev, "irq: Exit\n");
+ /*
+ * Schedule the tasklet to handle all cleanup of the current
+ * transaction. It will start a new transaction if there is
+ * one pending.
+ */
tasklet_schedule(&chan->tasklet);
+ chan_dbg(chan, "irq: Exit\n");
return IRQ_HANDLED;
}
static void dma_do_tasklet(unsigned long data)
{
struct fsldma_chan *chan = (struct fsldma_chan *)data;
- fsl_chan_ld_cleanup(chan);
+ struct fsl_desc_sw *desc, *_desc;
+ LIST_HEAD(ld_cleanup);
+ unsigned long flags;
+
+ chan_dbg(chan, "tasklet entry\n");
+
+ spin_lock_irqsave(&chan->desc_lock, flags);
+
+ /* update the cookie if we have some descriptors to cleanup */
+ if (!list_empty(&chan->ld_running)) {
+ dma_cookie_t cookie;
+
+ desc = to_fsl_desc(chan->ld_running.prev);
+ cookie = desc->async_tx.cookie;
+
+ chan->completed_cookie = cookie;
+ chan_dbg(chan, "completed_cookie=%d\n", cookie);
+ }
+
+ /*
+ * move the descriptors to a temporary list so we can drop the lock
+ * during the entire cleanup operation
+ */
+ list_splice_tail_init(&chan->ld_running, &ld_cleanup);
+
+ /* the hardware is now idle and ready for more */
+ chan->idle = true;
+
+ /*
+ * Start any pending transactions automatically
+ *
+ * In the ideal case, we keep the DMA controller busy while we go
+ * ahead and free the descriptors below.
+ */
+ fsl_chan_xfer_ld_queue(chan);
+ spin_unlock_irqrestore(&chan->desc_lock, flags);
+
+ /* Run the callback for each descriptor, in order */
+ list_for_each_entry_safe(desc, _desc, &ld_cleanup, node) {
+
+ /* Remove from the list of transactions */
+ list_del(&desc->node);
+
+ /* Run all cleanup for this descriptor */
+ fsldma_cleanup_descriptor(chan, desc);
+ }
+
+ chan_dbg(chan, "tasklet exit\n");
}
static irqreturn_t fsldma_ctrl_irq(int irq, void *data)
for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
chan = fdev->chan[i];
if (chan && chan->irq != NO_IRQ) {
- dev_dbg(fdev->dev, "free channel %d IRQ\n", chan->id);
+ chan_dbg(chan, "free per-channel IRQ\n");
free_irq(chan->irq, chan);
}
}
continue;
if (chan->irq == NO_IRQ) {
- dev_err(fdev->dev, "no interrupts property defined for "
- "DMA channel %d. Please fix your "
- "device tree\n", chan->id);
+ chan_err(chan, "interrupts property missing in device tree\n");
ret = -ENODEV;
goto out_unwind;
}
- dev_dbg(fdev->dev, "request channel %d IRQ\n", chan->id);
+ chan_dbg(chan, "request per-channel IRQ\n");
ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED,
"fsldma-chan", chan);
if (ret) {
- dev_err(fdev->dev, "unable to request IRQ for DMA "
- "channel %d\n", chan->id);
+ chan_err(chan, "unable to request per-channel IRQ\n");
goto out_unwind;
}
}
fdev->chan[chan->id] = chan;
tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
+ snprintf(chan->name, sizeof(chan->name), "chan%d", chan->id);
/* Initialize the channel */
dma_init(chan);
spin_lock_init(&chan->desc_lock);
INIT_LIST_HEAD(&chan->ld_pending);
INIT_LIST_HEAD(&chan->ld_running);
+ chan->idle = true;
chan->common.device = &fdev->common;
kfree(chan);
}
-static int __devinit fsldma_of_probe(struct of_device *op,
- const struct of_device_id *match)
+static int __devinit fsldma_of_probe(struct platform_device *op)
{
struct fsldma_device *fdev;
struct device_node *child;
INIT_LIST_HEAD(&fdev->common.channels);
/* ioremap the registers for use */
- fdev->regs = of_iomap(op->node, 0);
+ fdev->regs = of_iomap(op->dev.of_node, 0);
if (!fdev->regs) {
dev_err(&op->dev, "unable to ioremap registers\n");
err = -ENOMEM;
}
/* map the channel IRQ if it exists, but don't hookup the handler yet */
- fdev->irq = irq_of_parse_and_map(op->node, 0);
+ fdev->irq = irq_of_parse_and_map(op->dev.of_node, 0);
dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask);
+ dma_cap_set(DMA_SG, fdev->common.cap_mask);
dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
fdev->common.device_prep_dma_interrupt = fsl_dma_prep_interrupt;
fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
- fdev->common.device_is_tx_complete = fsl_dma_is_complete;
+ fdev->common.device_prep_dma_sg = fsl_dma_prep_sg;
+ fdev->common.device_tx_status = fsl_tx_status;
fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
fdev->common.device_prep_slave_sg = fsl_dma_prep_slave_sg;
- fdev->common.device_terminate_all = fsl_dma_device_terminate_all;
+ fdev->common.device_control = fsl_dma_device_control;
fdev->common.dev = &op->dev;
+ dma_set_mask(&(op->dev), DMA_BIT_MASK(36));
+
dev_set_drvdata(&op->dev, fdev);
/*
* of_platform_bus_remove(). Instead, we manually instantiate every DMA
* channel object.
*/
- for_each_child_of_node(op->node, child) {
+ for_each_child_of_node(op->dev.of_node, child) {
if (of_device_is_compatible(child, "fsl,eloplus-dma-channel")) {
fsl_dma_chan_probe(fdev, child,
FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
return err;
}
-static int fsldma_of_remove(struct of_device *op)
+static int fsldma_of_remove(struct platform_device *op)
{
struct fsldma_device *fdev;
unsigned int i;
{}
};
-static struct of_platform_driver fsldma_of_driver = {
- .name = "fsl-elo-dma",
- .match_table = fsldma_of_ids,
- .probe = fsldma_of_probe,
- .remove = fsldma_of_remove,
+static struct platform_driver fsldma_of_driver = {
+ .driver = {
+ .name = "fsl-elo-dma",
+ .owner = THIS_MODULE,
+ .of_match_table = fsldma_of_ids,
+ },
+ .probe = fsldma_of_probe,
+ .remove = fsldma_of_remove,
};
/*----------------------------------------------------------------------------*/
static __init int fsldma_init(void)
{
- int ret;
-
pr_info("Freescale Elo / Elo Plus DMA driver\n");
-
- ret = of_register_platform_driver(&fsldma_of_driver);
- if (ret)
- pr_err("fsldma: failed to register platform driver\n");
-
- return ret;
+ return platform_driver_register(&fsldma_of_driver);
}
static void __exit fsldma_exit(void)
{
- of_unregister_platform_driver(&fsldma_of_driver);
+ platform_driver_unregister(&fsldma_of_driver);
}
subsys_initcall(fsldma_init);
Code Review / linux-2.6.git / blobdiff