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dmaengine: dw: add support of iDMA 32-bit hardware
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iDMA 32-bit is Intel designed DMA controller that behaves like Synopsys
Designware DMA. This patch adds a support of the new Intel hardware.

Due to iDMA 32-bit has no autoconfiguration the platform code must
provide a platform data to dw_dma_probe().

By default full FIFO (1024 bytes) is assigned to channel 0. Here we
slice FIFO on equal parts between channels for iDMA 32-bit case.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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@andy-shev
andy-shev authored and Vinod Koul committed Jan 25, 2017
1 parent a9f4d1b commit 199244d
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Showing 2 changed files with 94 additions and 9 deletions.
101 changes: 92 additions & 9 deletions drivers/dma/dw/core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -138,16 +138,32 @@ static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
dwc->descs_allocated--;
}

static void dwc_initialize(struct dw_dma_chan *dwc)
static void dwc_initialize_chan_idma32(struct dw_dma_chan *dwc)
{
u32 cfghi = 0;
u32 cfglo = 0;

/* Set default burst alignment */
cfglo |= IDMA32C_CFGL_DST_BURST_ALIGN | IDMA32C_CFGL_SRC_BURST_ALIGN;

/* Low 4 bits of the request lines */
cfghi |= IDMA32C_CFGH_DST_PER(dwc->dws.dst_id & 0xf);
cfghi |= IDMA32C_CFGH_SRC_PER(dwc->dws.src_id & 0xf);

/* Request line extension (2 bits) */
cfghi |= IDMA32C_CFGH_DST_PER_EXT(dwc->dws.dst_id >> 4 & 0x3);
cfghi |= IDMA32C_CFGH_SRC_PER_EXT(dwc->dws.src_id >> 4 & 0x3);

channel_writel(dwc, CFG_LO, cfglo);
channel_writel(dwc, CFG_HI, cfghi);
}

static void dwc_initialize_chan_dw(struct dw_dma_chan *dwc)
{
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
u32 cfghi = DWC_CFGH_FIFO_MODE;
u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
bool hs_polarity = dwc->dws.hs_polarity;

if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags))
return;

cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);

Expand All @@ -156,6 +172,19 @@ static void dwc_initialize(struct dw_dma_chan *dwc)

channel_writel(dwc, CFG_LO, cfglo);
channel_writel(dwc, CFG_HI, cfghi);
}

static void dwc_initialize(struct dw_dma_chan *dwc)
{
struct dw_dma *dw = to_dw_dma(dwc->chan.device);

if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags))
return;

if (dw->pdata->is_idma32)
dwc_initialize_chan_idma32(dwc);
else
dwc_initialize_chan_dw(dwc);

/* Enable interrupts */
channel_set_bit(dw, MASK.XFER, dwc->mask);
Expand Down Expand Up @@ -187,8 +216,13 @@ static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
static u32 bytes2block(struct dw_dma_chan *dwc, size_t bytes,
unsigned int width, size_t *len)
{
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
u32 block;

/* Always in bytes for iDMA 32-bit */
if (dw->pdata->is_idma32)
width = 0;

if ((bytes >> width) > dwc->block_size) {
block = dwc->block_size;
*len = block << width;
Expand All @@ -202,6 +236,11 @@ static u32 bytes2block(struct dw_dma_chan *dwc, size_t bytes,

static size_t block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
{
struct dw_dma *dw = to_dw_dma(dwc->chan.device);

if (dw->pdata->is_idma32)
return IDMA32C_CTLH_BLOCK_TS(block);

return DWC_CTLH_BLOCK_TS(block) << width;
}

Expand Down Expand Up @@ -915,14 +954,16 @@ static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dma_slave_config *sc = &dwc->dma_sconfig;
struct dw_dma *dw = to_dw_dma(chan->device);
/*
* Fix sconfig's burst size according to dw_dmac. We need to convert
* them as:
* 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
*
* NOTE: burst size 2 is not supported by DesignWare controller.
* iDMA 32-bit supports it.
*/
u32 s = 2;
u32 s = dw->pdata->is_idma32 ? 1 : 2;

/* Check if chan will be configured for slave transfers */
if (!is_slave_direction(sconfig->direction))
Expand All @@ -937,12 +978,19 @@ static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
return 0;
}

static void dwc_chan_pause(struct dw_dma_chan *dwc)
static void dwc_chan_pause(struct dw_dma_chan *dwc, bool drain)
{
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
unsigned int count = 20; /* timeout iterations */
u32 cfglo;

cfglo = channel_readl(dwc, CFG_LO);
if (dw->pdata->is_idma32) {
if (drain)
cfglo |= IDMA32C_CFGL_CH_DRAIN;
else
cfglo &= ~IDMA32C_CFGL_CH_DRAIN;
}
channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--)
udelay(2);
Expand All @@ -956,7 +1004,7 @@ static int dwc_pause(struct dma_chan *chan)
unsigned long flags;

spin_lock_irqsave(&dwc->lock, flags);
dwc_chan_pause(dwc);
dwc_chan_pause(dwc, false);
spin_unlock_irqrestore(&dwc->lock, flags);

return 0;
Expand Down Expand Up @@ -998,6 +1046,8 @@ static int dwc_terminate_all(struct dma_chan *chan)

clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);

dwc_chan_pause(dwc, true);

dwc_chan_disable(dw, dwc);

dwc_chan_resume(dwc);
Expand Down Expand Up @@ -1090,6 +1140,32 @@ static void dwc_issue_pending(struct dma_chan *chan)

/*----------------------------------------------------------------------*/

/*
* Program FIFO size of channels.
*
* By default full FIFO (1024 bytes) is assigned to channel 0. Here we
* slice FIFO on equal parts between channels.
*/
static void idma32_fifo_partition(struct dw_dma *dw)
{
u64 value = IDMA32C_FP_PSIZE_CH0(128) | IDMA32C_FP_PSIZE_CH1(128) |
IDMA32C_FP_UPDATE;
u64 fifo_partition = 0;

if (!dw->pdata->is_idma32)
return;

/* Fill FIFO_PARTITION low bits (Channels 0..1, 4..5) */
fifo_partition |= value << 0;

/* Fill FIFO_PARTITION high bits (Channels 2..3, 6..7) */
fifo_partition |= value << 32;

/* Program FIFO Partition registers - 128 bytes for each channel */
idma32_writeq(dw, FIFO_PARTITION1, fifo_partition);
idma32_writeq(dw, FIFO_PARTITION0, fifo_partition);
}

static void dw_dma_off(struct dw_dma *dw)
{
unsigned int i;
Expand Down Expand Up @@ -1509,8 +1585,13 @@ int dw_dma_probe(struct dw_dma_chip *chip)
/* Force dma off, just in case */
dw_dma_off(dw);

idma32_fifo_partition(dw);

/* Device and instance ID for IRQ and DMA pool */
snprintf(dw->name, sizeof(dw->name), "dw:dmac%d", chip->id);
if (pdata->is_idma32)
snprintf(dw->name, sizeof(dw->name), "idma32:dmac%d", chip->id);
else
snprintf(dw->name, sizeof(dw->name), "dw:dmac%d", chip->id);

/* Create a pool of consistent memory blocks for hardware descriptors */
dw->desc_pool = dmam_pool_create(dw->name, chip->dev,
Expand Down Expand Up @@ -1673,6 +1754,8 @@ int dw_dma_enable(struct dw_dma_chip *chip)
{
struct dw_dma *dw = chip->dw;

idma32_fifo_partition(dw);

dw_dma_on(dw);
return 0;
}
Expand Down
2 changes: 2 additions & 0 deletions include/linux/platform_data/dma-dw.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,7 @@ struct dw_dma_slave {
* @is_private: The device channels should be marked as private and not for
* by the general purpose DMA channel allocator.
* @is_memcpy: The device channels do support memory-to-memory transfers.
* @is_idma32: The type of the DMA controller is iDMA32
* @chan_allocation_order: Allocate channels starting from 0 or 7
* @chan_priority: Set channel priority increasing from 0 to 7 or 7 to 0.
* @block_size: Maximum block size supported by the controller
Expand All @@ -53,6 +54,7 @@ struct dw_dma_platform_data {
unsigned int nr_channels;
bool is_private;
bool is_memcpy;
bool is_idma32;
#define CHAN_ALLOCATION_ASCENDING 0 /* zero to seven */
#define CHAN_ALLOCATION_DESCENDING 1 /* seven to zero */
unsigned char chan_allocation_order;
Expand Down

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