* after the final transfer signalled by LBREQ or LSREQ. The DMAC
* will then move to the next LLI entry.
*
- * Only the former works sanely with scatter lists, so we only implement
- * the DMAC flow control method. However, peripherals which use the LBREQ
- * and LSREQ signals (eg, MMCI) are unable to use this mode, which through
- * these hardware restrictions prevents them from using scatter DMA.
- *
* Global TODO:
* - Break out common code from arch/arm/mach-s3c64xx and share
*/
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>
+#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#define DRIVER_NAME "pl08xdmac"
+static struct amba_driver pl08x_amba_driver;
+
/**
* struct vendor_data - vendor-specific config parameters for PL08x derivatives
* @channels: the number of channels available in this variant
* byte data), slave is still not aligned, then its width will be reduced to
* BYTE.
* - prefers the destination bus if both available
- * - if fixed address on one bus the other will be chosen
+ * - prefers bus with fixed address (i.e. peripheral)
*/
static void pl08x_choose_master_bus(struct pl08x_lli_build_data *bd,
struct pl08x_bus_data **mbus, struct pl08x_bus_data **sbus, u32 cctl)
{
if (!(cctl & PL080_CONTROL_DST_INCR)) {
- *mbus = &bd->srcbus;
- *sbus = &bd->dstbus;
- } else if (!(cctl & PL080_CONTROL_SRC_INCR)) {
*mbus = &bd->dstbus;
*sbus = &bd->srcbus;
+ } else if (!(cctl & PL080_CONTROL_SRC_INCR)) {
+ *mbus = &bd->srcbus;
+ *sbus = &bd->dstbus;
} else {
- if (bd->dstbus.buswidth == 4) {
- *mbus = &bd->dstbus;
- *sbus = &bd->srcbus;
- } else if (bd->srcbus.buswidth == 4) {
- *mbus = &bd->srcbus;
- *sbus = &bd->dstbus;
- } else if (bd->dstbus.buswidth == 2) {
+ if (bd->dstbus.buswidth >= bd->srcbus.buswidth) {
*mbus = &bd->dstbus;
*sbus = &bd->srcbus;
- } else if (bd->srcbus.buswidth == 2) {
+ } else {
*mbus = &bd->srcbus;
*sbus = &bd->dstbus;
- } else {
- /* bd->srcbus.buswidth == 1 */
- *mbus = &bd->dstbus;
- *sbus = &bd->srcbus;
}
}
}
bd->remainder -= len;
}
+static inline void prep_byte_width_lli(struct pl08x_lli_build_data *bd,
+ u32 *cctl, u32 len, int num_llis, size_t *total_bytes)
+{
+ *cctl = pl08x_cctl_bits(*cctl, 1, 1, len);
+ pl08x_fill_lli_for_desc(bd, num_llis, len, *cctl);
+ (*total_bytes) += len;
+}
+
/*
* This fills in the table of LLIs for the transfer descriptor
* Note that we assume we never have to change the burst sizes
struct pl08x_bus_data *mbus, *sbus;
struct pl08x_lli_build_data bd;
int num_llis = 0;
- u32 cctl;
+ u32 cctl, early_bytes = 0;
size_t max_bytes_per_lli, total_bytes = 0;
struct pl08x_lli *llis_va;
bd.srcbus.buswidth = bd.srcbus.maxwidth;
bd.dstbus.buswidth = bd.dstbus.maxwidth;
- /*
- * Bytes transferred == tsize * MIN(buswidths), not max(buswidths)
- */
- max_bytes_per_lli = min(bd.srcbus.buswidth, bd.dstbus.buswidth) *
- PL080_CONTROL_TRANSFER_SIZE_MASK;
-
/* We need to count this down to zero */
bd.remainder = txd->len;
pl08x_choose_master_bus(&bd, &mbus, &sbus, cctl);
- dev_vdbg(&pl08x->adev->dev, "src=0x%08x%s/%u dst=0x%08x%s/%u len=%zu llimax=%zu\n",
+ dev_vdbg(&pl08x->adev->dev, "src=0x%08x%s/%u dst=0x%08x%s/%u len=%zu\n",
bd.srcbus.addr, cctl & PL080_CONTROL_SRC_INCR ? "+" : "",
bd.srcbus.buswidth,
bd.dstbus.addr, cctl & PL080_CONTROL_DST_INCR ? "+" : "",
bd.dstbus.buswidth,
- bd.remainder, max_bytes_per_lli);
+ bd.remainder);
dev_vdbg(&pl08x->adev->dev, "mbus=%s sbus=%s\n",
mbus == &bd.srcbus ? "src" : "dst",
sbus == &bd.srcbus ? "src" : "dst");
- if (txd->len < mbus->buswidth) {
- /* Less than a bus width available - send as single bytes */
- while (bd.remainder) {
- dev_vdbg(&pl08x->adev->dev,
- "%s single byte LLIs for a transfer of "
- "less than a bus width (remain 0x%08x)\n",
- __func__, bd.remainder);
- cctl = pl08x_cctl_bits(cctl, 1, 1, 1);
- pl08x_fill_lli_for_desc(&bd, num_llis++, 1, cctl);
- total_bytes++;
+ /*
+ * Zero length is only allowed if all these requirements are met:
+ * - flow controller is peripheral.
+ * - src.addr is aligned to src.width
+ * - dst.addr is aligned to dst.width
+ *
+ * sg_len == 1 should be true, as there can be two cases here:
+ * - Memory addresses are contiguous and are not scattered. Here, Only
+ * one sg will be passed by user driver, with memory address and zero
+ * length. We pass this to controller and after the transfer it will
+ * receive the last burst request from peripheral and so transfer
+ * finishes.
+ *
+ * - Memory addresses are scattered and are not contiguous. Here,
+ * Obviously as DMA controller doesn't know when a lli's transfer gets
+ * over, it can't load next lli. So in this case, there has to be an
+ * assumption that only one lli is supported. Thus, we can't have
+ * scattered addresses.
+ */
+ if (!bd.remainder) {
+ u32 fc = (txd->ccfg & PL080_CONFIG_FLOW_CONTROL_MASK) >>
+ PL080_CONFIG_FLOW_CONTROL_SHIFT;
+ if (!((fc >= PL080_FLOW_SRC2DST_DST) &&
+ (fc <= PL080_FLOW_SRC2DST_SRC))) {
+ dev_err(&pl08x->adev->dev, "%s sg len can't be zero",
+ __func__);
+ return 0;
}
- } else {
- /* Make one byte LLIs until master bus is aligned */
- while ((mbus->addr) % (mbus->buswidth)) {
- dev_vdbg(&pl08x->adev->dev,
- "%s adjustment lli for less than bus width "
- "(remain 0x%08x)\n",
- __func__, bd.remainder);
- cctl = pl08x_cctl_bits(cctl, 1, 1, 1);
- pl08x_fill_lli_for_desc(&bd, num_llis++, 1, cctl);
- total_bytes++;
+
+ if ((bd.srcbus.addr % bd.srcbus.buswidth) ||
+ (bd.srcbus.addr % bd.srcbus.buswidth)) {
+ dev_err(&pl08x->adev->dev,
+ "%s src & dst address must be aligned to src"
+ " & dst width if peripheral is flow controller",
+ __func__);
+ return 0;
}
+ cctl = pl08x_cctl_bits(cctl, bd.srcbus.buswidth,
+ bd.dstbus.buswidth, 0);
+ pl08x_fill_lli_for_desc(&bd, num_llis++, 0, cctl);
+ }
+
+ /*
+ * Send byte by byte for following cases
+ * - Less than a bus width available
+ * - until master bus is aligned
+ */
+ if (bd.remainder < mbus->buswidth)
+ early_bytes = bd.remainder;
+ else if ((mbus->addr) % (mbus->buswidth)) {
+ early_bytes = mbus->buswidth - (mbus->addr) % (mbus->buswidth);
+ if ((bd.remainder - early_bytes) < mbus->buswidth)
+ early_bytes = bd.remainder;
+ }
+
+ if (early_bytes) {
+ dev_vdbg(&pl08x->adev->dev, "%s byte width LLIs "
+ "(remain 0x%08x)\n", __func__, bd.remainder);
+ prep_byte_width_lli(&bd, &cctl, early_bytes, num_llis++,
+ &total_bytes);
+ }
+
+ if (bd.remainder) {
/*
* Master now aligned
* - if slave is not then we must set its width down
sbus->buswidth = 1;
}
+ /* Bytes transferred = tsize * src width, not MIN(buswidths) */
+ max_bytes_per_lli = bd.srcbus.buswidth *
+ PL080_CONTROL_TRANSFER_SIZE_MASK;
+
/*
* Make largest possible LLIs until less than one bus
* width left
*/
while (bd.remainder > (mbus->buswidth - 1)) {
- size_t lli_len, tsize;
+ size_t lli_len, tsize, width;
/*
* If enough left try to send max possible,
* otherwise try to send the remainder
*/
lli_len = min(bd.remainder, max_bytes_per_lli);
+
/*
- * Check against minimum bus alignment: Calculate actual
+ * Check against maximum bus alignment: Calculate actual
* transfer size in relation to bus width and get a
- * maximum remainder of the smallest bus width - 1
+ * maximum remainder of the highest bus width - 1
*/
- tsize = lli_len / min(mbus->buswidth, sbus->buswidth);
- lli_len = tsize * min(mbus->buswidth, sbus->buswidth);
+ width = max(mbus->buswidth, sbus->buswidth);
+ lli_len = (lli_len / width) * width;
+ tsize = lli_len / bd.srcbus.buswidth;
dev_vdbg(&pl08x->adev->dev,
"%s fill lli with single lli chunk of "
/*
* Send any odd bytes
*/
- while (bd.remainder) {
- cctl = pl08x_cctl_bits(cctl, 1, 1, 1);
+ if (bd.remainder) {
dev_vdbg(&pl08x->adev->dev,
- "%s align with boundary, single odd byte (remain %zu)\n",
+ "%s align with boundary, send odd bytes (remain %zu)\n",
__func__, bd.remainder);
- pl08x_fill_lli_for_desc(&bd, num_llis++, 1, cctl);
- total_bytes++;
+ prep_byte_width_lli(&bd, &cctl, bd.remainder,
+ num_llis++, &total_bytes);
}
}
num_llis = pl08x_fill_llis_for_desc(pl08x, txd);
if (!num_llis) {
- kfree(txd);
+ spin_lock_irqsave(&plchan->lock, flags);
+ pl08x_free_txd(pl08x, txd);
+ spin_unlock_irqrestore(&plchan->lock, flags);
return -EINVAL;
}
struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_txd *txd;
- int ret;
+ int ret, tmp;
/*
* Current implementation ASSUMES only one sg
txd->len = sgl->length;
if (direction == DMA_TO_DEVICE) {
- txd->ccfg |= PL080_FLOW_MEM2PER << PL080_CONFIG_FLOW_CONTROL_SHIFT;
txd->cctl = plchan->dst_cctl;
txd->src_addr = sgl->dma_address;
txd->dst_addr = plchan->dst_addr;
} else if (direction == DMA_FROM_DEVICE) {
- txd->ccfg |= PL080_FLOW_PER2MEM << PL080_CONFIG_FLOW_CONTROL_SHIFT;
txd->cctl = plchan->src_cctl;
txd->src_addr = plchan->src_addr;
txd->dst_addr = sgl->dma_address;
return NULL;
}
+ if (plchan->cd->device_fc)
+ tmp = (direction == DMA_TO_DEVICE) ? PL080_FLOW_MEM2PER_PER :
+ PL080_FLOW_PER2MEM_PER;
+ else
+ tmp = (direction == DMA_TO_DEVICE) ? PL080_FLOW_MEM2PER :
+ PL080_FLOW_PER2MEM;
+
+ txd->ccfg |= tmp << PL080_CONFIG_FLOW_CONTROL_SHIFT;
+
ret = pl08x_prep_channel_resources(plchan, txd);
if (ret)
return NULL;
bool pl08x_filter_id(struct dma_chan *chan, void *chan_id)
{
- struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
+ struct pl08x_dma_chan *plchan;
char *name = chan_id;
+ /* Reject channels for devices not bound to this driver */
+ if (chan->device->dev->driver != &pl08x_amba_driver.drv)
+ return false;
+
+ plchan = to_pl08x_chan(chan);
+
/* Check that the channel is not taken! */
if (!strcmp(plchan->name, name))
return true;
git.openpandora.org / pandora-kernel.git / blobdiff