Commit 5413da81 authored by Matt Porter's avatar Matt Porter Committed by Chris Ball

mmc: davinci_mmc: convert to DMA engine API

Removes use of the DaVinci EDMA private DMA API and replaces
it with use of the DMA engine API.
Signed-off-by: default avatarMatt Porter <mporter@ti.com>
Tested-by: default avatarKoen Kooi <koen@dominion.thruhere.net>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent d8e2ac33
......@@ -30,11 +30,12 @@
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/edma.h>
#include <linux/mmc/mmc.h>
#include <mach/mmc.h>
#include <mach/edma.h>
/*
* Register Definitions
......@@ -200,21 +201,13 @@ struct mmc_davinci_host {
u32 bytes_left;
u32 rxdma, txdma;
struct dma_chan *dma_tx;
struct dma_chan *dma_rx;
bool use_dma;
bool do_dma;
bool sdio_int;
bool active_request;
/* Scatterlist DMA uses one or more parameter RAM entries:
* the main one (associated with rxdma or txdma) plus zero or
* more links. The entries for a given transfer differ only
* by memory buffer (address, length) and link field.
*/
struct edmacc_param tx_template;
struct edmacc_param rx_template;
unsigned n_link;
u32 links[MAX_NR_SG - 1];
/* For PIO we walk scatterlists one segment at a time. */
unsigned int sg_len;
struct scatterlist *sg;
......@@ -410,153 +403,74 @@ static void mmc_davinci_start_command(struct mmc_davinci_host *host,
static void davinci_abort_dma(struct mmc_davinci_host *host)
{
int sync_dev;
struct dma_chan *sync_dev;
if (host->data_dir == DAVINCI_MMC_DATADIR_READ)
sync_dev = host->rxdma;
sync_dev = host->dma_rx;
else
sync_dev = host->txdma;
edma_stop(sync_dev);
edma_clean_channel(sync_dev);
}
static void
mmc_davinci_xfer_done(struct mmc_davinci_host *host, struct mmc_data *data);
static void mmc_davinci_dma_cb(unsigned channel, u16 ch_status, void *data)
{
if (DMA_COMPLETE != ch_status) {
struct mmc_davinci_host *host = data;
/* Currently means: DMA Event Missed, or "null" transfer
* request was seen. In the future, TC errors (like bad
* addresses) might be presented too.
*/
dev_warn(mmc_dev(host->mmc), "DMA %s error\n",
(host->data->flags & MMC_DATA_WRITE)
? "write" : "read");
host->data->error = -EIO;
mmc_davinci_xfer_done(host, host->data);
}
}
/* Set up tx or rx template, to be modified and updated later */
static void __init mmc_davinci_dma_setup(struct mmc_davinci_host *host,
bool tx, struct edmacc_param *template)
{
unsigned sync_dev;
const u16 acnt = 4;
const u16 bcnt = rw_threshold >> 2;
const u16 ccnt = 0;
u32 src_port = 0;
u32 dst_port = 0;
s16 src_bidx, dst_bidx;
s16 src_cidx, dst_cidx;
/*
* A-B Sync transfer: each DMA request is for one "frame" of
* rw_threshold bytes, broken into "acnt"-size chunks repeated
* "bcnt" times. Each segment needs "ccnt" such frames; since
* we tell the block layer our mmc->max_seg_size limit, we can
* trust (later) that it's within bounds.
*
* The FIFOs are read/written in 4-byte chunks (acnt == 4) and
* EDMA will optimize memory operations to use larger bursts.
*/
if (tx) {
sync_dev = host->txdma;
/* src_prt, ccnt, and link to be set up later */
src_bidx = acnt;
src_cidx = acnt * bcnt;
dst_port = host->mem_res->start + DAVINCI_MMCDXR;
dst_bidx = 0;
dst_cidx = 0;
} else {
sync_dev = host->rxdma;
src_port = host->mem_res->start + DAVINCI_MMCDRR;
src_bidx = 0;
src_cidx = 0;
/* dst_prt, ccnt, and link to be set up later */
dst_bidx = acnt;
dst_cidx = acnt * bcnt;
}
/*
* We can't use FIFO mode for the FIFOs because MMC FIFO addresses
* are not 256-bit (32-byte) aligned. So we use INCR, and the W8BIT
* parameter is ignored.
*/
edma_set_src(sync_dev, src_port, INCR, W8BIT);
edma_set_dest(sync_dev, dst_port, INCR, W8BIT);
edma_set_src_index(sync_dev, src_bidx, src_cidx);
edma_set_dest_index(sync_dev, dst_bidx, dst_cidx);
edma_set_transfer_params(sync_dev, acnt, bcnt, ccnt, 8, ABSYNC);
edma_read_slot(sync_dev, template);
sync_dev = host->dma_tx;
/* don't bother with irqs or chaining */
template->opt |= EDMA_CHAN_SLOT(sync_dev) << 12;
dmaengine_terminate_all(sync_dev);
}
static void mmc_davinci_send_dma_request(struct mmc_davinci_host *host,
static int mmc_davinci_send_dma_request(struct mmc_davinci_host *host,
struct mmc_data *data)
{
struct edmacc_param *template;
int channel, slot;
unsigned link;
struct scatterlist *sg;
unsigned sg_len;
unsigned bytes_left = host->bytes_left;
const unsigned shift = ffs(rw_threshold) - 1;
struct dma_chan *chan;
struct dma_async_tx_descriptor *desc;
int ret = 0;
if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
template = &host->tx_template;
channel = host->txdma;
struct dma_slave_config dma_tx_conf = {
.direction = DMA_MEM_TO_DEV,
.dst_addr = host->mem_res->start + DAVINCI_MMCDXR,
.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
.dst_maxburst =
rw_threshold / DMA_SLAVE_BUSWIDTH_4_BYTES,
};
chan = host->dma_tx;
dmaengine_slave_config(host->dma_tx, &dma_tx_conf);
desc = dmaengine_prep_slave_sg(host->dma_tx,
data->sg,
host->sg_len,
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
dev_dbg(mmc_dev(host->mmc),
"failed to allocate DMA TX descriptor");
ret = -1;
goto out;
}
} else {
template = &host->rx_template;
channel = host->rxdma;
struct dma_slave_config dma_rx_conf = {
.direction = DMA_DEV_TO_MEM,
.src_addr = host->mem_res->start + DAVINCI_MMCDRR,
.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
.src_maxburst =
rw_threshold / DMA_SLAVE_BUSWIDTH_4_BYTES,
};
chan = host->dma_rx;
dmaengine_slave_config(host->dma_rx, &dma_rx_conf);
desc = dmaengine_prep_slave_sg(host->dma_rx,
data->sg,
host->sg_len,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
dev_dbg(mmc_dev(host->mmc),
"failed to allocate DMA RX descriptor");
ret = -1;
goto out;
}
/* We know sg_len and ccnt will never be out of range because
* we told the mmc layer which in turn tells the block layer
* to ensure that it only hands us one scatterlist segment
* per EDMA PARAM entry. Update the PARAM
* entries needed for each segment of this scatterlist.
*/
for (slot = channel, link = 0, sg = data->sg, sg_len = host->sg_len;
sg_len-- != 0 && bytes_left;
sg = sg_next(sg), slot = host->links[link++]) {
u32 buf = sg_dma_address(sg);
unsigned count = sg_dma_len(sg);
template->link_bcntrld = sg_len
? (EDMA_CHAN_SLOT(host->links[link]) << 5)
: 0xffff;
if (count > bytes_left)
count = bytes_left;
bytes_left -= count;
if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE)
template->src = buf;
else
template->dst = buf;
template->ccnt = count >> shift;
edma_write_slot(slot, template);
}
if (host->version == MMC_CTLR_VERSION_2)
edma_clear_event(channel);
dmaengine_submit(desc);
dma_async_issue_pending(chan);
edma_start(channel);
out:
return ret;
}
static int mmc_davinci_start_dma_transfer(struct mmc_davinci_host *host,
......@@ -564,6 +478,7 @@ static int mmc_davinci_start_dma_transfer(struct mmc_davinci_host *host,
{
int i;
int mask = rw_threshold - 1;
int ret = 0;
host->sg_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
((data->flags & MMC_DATA_WRITE)
......@@ -583,70 +498,48 @@ static int mmc_davinci_start_dma_transfer(struct mmc_davinci_host *host,
}
host->do_dma = 1;
mmc_davinci_send_dma_request(host, data);
ret = mmc_davinci_send_dma_request(host, data);
return 0;
return ret;
}
static void __init_or_module
davinci_release_dma_channels(struct mmc_davinci_host *host)
{
unsigned i;
if (!host->use_dma)
return;
for (i = 0; i < host->n_link; i++)
edma_free_slot(host->links[i]);
edma_free_channel(host->txdma);
edma_free_channel(host->rxdma);
dma_release_channel(host->dma_tx);
dma_release_channel(host->dma_rx);
}
static int __init davinci_acquire_dma_channels(struct mmc_davinci_host *host)
{
u32 link_size;
int r, i;
/* Acquire master DMA write channel */
r = edma_alloc_channel(host->txdma, mmc_davinci_dma_cb, host,
EVENTQ_DEFAULT);
if (r < 0) {
dev_warn(mmc_dev(host->mmc), "alloc %s channel err %d\n",
"tx", r);
return r;
}
mmc_davinci_dma_setup(host, true, &host->tx_template);
/* Acquire master DMA read channel */
r = edma_alloc_channel(host->rxdma, mmc_davinci_dma_cb, host,
EVENTQ_DEFAULT);
if (r < 0) {
dev_warn(mmc_dev(host->mmc), "alloc %s channel err %d\n",
"rx", r);
goto free_master_write;
}
mmc_davinci_dma_setup(host, false, &host->rx_template);
int r;
dma_cap_mask_t mask;
/* Allocate parameter RAM slots, which will later be bound to a
* channel as needed to handle a scatterlist.
*/
link_size = min_t(unsigned, host->nr_sg, ARRAY_SIZE(host->links));
for (i = 0; i < link_size; i++) {
r = edma_alloc_slot(EDMA_CTLR(host->txdma), EDMA_SLOT_ANY);
if (r < 0) {
dev_dbg(mmc_dev(host->mmc), "dma PaRAM alloc --> %d\n",
r);
break;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
host->dma_tx =
dma_request_channel(mask, edma_filter_fn, &host->txdma);
if (!host->dma_tx) {
dev_err(mmc_dev(host->mmc), "Can't get dma_tx channel\n");
return -ENODEV;
}
host->links[i] = r;
host->dma_rx =
dma_request_channel(mask, edma_filter_fn, &host->rxdma);
if (!host->dma_rx) {
dev_err(mmc_dev(host->mmc), "Can't get dma_rx channel\n");
r = -ENODEV;
goto free_master_write;
}
host->n_link = i;
return 0;
free_master_write:
edma_free_channel(host->txdma);
dma_release_channel(host->dma_tx);
return r;
}
......@@ -1359,7 +1252,7 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev)
* Each hw_seg uses one EDMA parameter RAM slot, always one
* channel and then usually some linked slots.
*/
mmc->max_segs = 1 + host->n_link;
mmc->max_segs = MAX_NR_SG;
/* EDMA limit per hw segment (one or two MBytes) */
mmc->max_seg_size = MAX_CCNT * rw_threshold;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment