[PATCH v2 3/4] dmaengine: at_xdmac: add support for sama7g5 based at_xdmac

From: Eugen Hristev
Date: Fri Oct 16 2020 - 05:39:10 EST

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SAMA7G5 SoC uses a slightly different variant of the AT_XDMAC.
Added support by a new compatible and a layout struct that copes
to the specific version considering the compatible string.
Only the differences in register map are present in the layout struct.
I reworked the register access for this part that has the differences.
Also the Source/Destination Interface bits are no longer valid for this
variant of the XDMAC. Thus, the layout also has a bool for specifying
whether these bits are required or not.

Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
---
Changes in v2:
- removed patch that was moving the register definitions to a different file
- changed according to review from Tudor : removed SIF(0)/DIF(0) and
added comments, changed alignment on some 'or' operations, added const on
layouts structs

drivers/dma/at_xdmac.c | 110 +++++++++++++++++++++++++++++++----------
1 file changed, 84 insertions(+), 26 deletions(-)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 94f7023472bb..bfbf6375c293 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -38,13 +38,6 @@
#define AT_XDMAC_GE 0x1C /* Global Channel Enable Register */
#define AT_XDMAC_GD 0x20 /* Global Channel Disable Register */
#define AT_XDMAC_GS 0x24 /* Global Channel Status Register */
-#define AT_XDMAC_GRS 0x28 /* Global Channel Read Suspend Register */
-#define AT_XDMAC_GWS 0x2C /* Global Write Suspend Register */
-#define AT_XDMAC_GRWS 0x30 /* Global Channel Read Write Suspend Register */
-#define AT_XDMAC_GRWR 0x34 /* Global Channel Read Write Resume Register */
-#define AT_XDMAC_GSWR 0x38 /* Global Channel Software Request Register */
-#define AT_XDMAC_GSWS 0x3C /* Global channel Software Request Status Register */
-#define AT_XDMAC_GSWF 0x40 /* Global Channel Software Flush Request Register */
#define AT_XDMAC_VERSION 0xFFC /* XDMAC Version Register */

/* Channel relative registers offsets */
@@ -150,8 +143,6 @@
#define AT_XDMAC_CSUS 0x30 /* Channel Source Microblock Stride */
#define AT_XDMAC_CDUS 0x34 /* Channel Destination Microblock Stride */

-#define AT_XDMAC_CHAN_REG_BASE 0x50 /* Channel registers base address */
-
/* Microblock control members */
#define AT_XDMAC_MBR_UBC_UBLEN_MAX 0xFFFFFFUL /* Maximum Microblock Length */
#define AT_XDMAC_MBR_UBC_NDE (0x1 << 24) /* Next Descriptor Enable */
@@ -179,6 +170,27 @@ enum atc_status {
AT_XDMAC_CHAN_IS_PAUSED,
};

+struct at_xdmac_layout {
+ /* Global Channel Read Suspend Register */
+ u8 grs;
+ /* Global Write Suspend Register */
+ u8 gws;
+ /* Global Channel Read Write Suspend Register */
+ u8 grws;
+ /* Global Channel Read Write Resume Register */
+ u8 grwr;
+ /* Global Channel Software Request Register */
+ u8 gswr;
+ /* Global channel Software Request Status Register */
+ u8 gsws;
+ /* Global Channel Software Flush Request Register */
+ u8 gswf;
+ /* Channel reg base */
+ u8 chan_cc_reg_base;
+ /* Source/Destination Interface must be specified or not */
+ bool sdif;
+};
+
/* ----- Channels ----- */
struct at_xdmac_chan {
struct dma_chan chan;
@@ -212,6 +224,7 @@ struct at_xdmac {
struct clk *clk;
u32 save_gim;
struct dma_pool *at_xdmac_desc_pool;
+ const struct at_xdmac_layout *layout;
struct at_xdmac_chan chan[];
};

@@ -244,9 +257,33 @@ struct at_xdmac_desc {
struct list_head xfer_node;
} __aligned(sizeof(u64));

+static const struct at_xdmac_layout at_xdmac_sama5d4_layout = {
+ .grs = 0x28,
+ .gws = 0x2C,
+ .grws = 0x30,
+ .grwr = 0x34,
+ .gswr = 0x38,
+ .gsws = 0x3C,
+ .gswf = 0x40,
+ .chan_cc_reg_base = 0x50,
+ .sdif = true,
+};
+
+static const struct at_xdmac_layout at_xdmac_sama7g5_layout = {
+ .grs = 0x30,
+ .gws = 0x38,
+ .grws = 0x40,
+ .grwr = 0x44,
+ .gswr = 0x48,
+ .gsws = 0x4C,
+ .gswf = 0x50,
+ .chan_cc_reg_base = 0x60,
+ .sdif = false,
+};
+
static inline void __iomem *at_xdmac_chan_reg_base(struct at_xdmac *atxdmac, unsigned int chan_nb)
{
- return atxdmac->regs + (AT_XDMAC_CHAN_REG_BASE + chan_nb * 0x40);
+ return atxdmac->regs + (atxdmac->layout->chan_cc_reg_base + chan_nb * 0x40);
}

#define at_xdmac_read(atxdmac, reg) readl_relaxed((atxdmac)->regs + (reg))
@@ -345,8 +382,10 @@ static void at_xdmac_start_xfer(struct at_xdmac_chan *atchan,
first->active_xfer = true;

/* Tell xdmac where to get the first descriptor. */
- reg = AT_XDMAC_CNDA_NDA(first->tx_dma_desc.phys)
- | AT_XDMAC_CNDA_NDAIF(atchan->memif);
+ reg = AT_XDMAC_CNDA_NDA(first->tx_dma_desc.phys);
+ if (atxdmac->layout->sdif)
+ reg |= AT_XDMAC_CNDA_NDAIF(atchan->memif);
+
at_xdmac_chan_write(atchan, AT_XDMAC_CNDA, reg);

/*
@@ -541,6 +580,7 @@ static int at_xdmac_compute_chan_conf(struct dma_chan *chan,
enum dma_transfer_direction direction)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
+ struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
int csize, dwidth;

if (direction == DMA_DEV_TO_MEM) {
@@ -548,12 +588,14 @@ static int at_xdmac_compute_chan_conf(struct dma_chan *chan,
AT91_XDMAC_DT_PERID(atchan->perid)
| AT_XDMAC_CC_DAM_INCREMENTED_AM
| AT_XDMAC_CC_SAM_FIXED_AM
- | AT_XDMAC_CC_DIF(atchan->memif)
- | AT_XDMAC_CC_SIF(atchan->perif)
| AT_XDMAC_CC_SWREQ_HWR_CONNECTED
| AT_XDMAC_CC_DSYNC_PER2MEM
| AT_XDMAC_CC_MBSIZE_SIXTEEN
| AT_XDMAC_CC_TYPE_PER_TRAN;
+ if (atxdmac->layout->sdif)
+ atchan->cfg |= AT_XDMAC_CC_DIF(atchan->memif) |
+ AT_XDMAC_CC_SIF(atchan->perif);
+
csize = ffs(atchan->sconfig.src_maxburst) - 1;
if (csize < 0) {
dev_err(chan2dev(chan), "invalid src maxburst value\n");
@@ -571,12 +613,14 @@ static int at_xdmac_compute_chan_conf(struct dma_chan *chan,
AT91_XDMAC_DT_PERID(atchan->perid)
| AT_XDMAC_CC_DAM_FIXED_AM
| AT_XDMAC_CC_SAM_INCREMENTED_AM
- | AT_XDMAC_CC_DIF(atchan->perif)
- | AT_XDMAC_CC_SIF(atchan->memif)
| AT_XDMAC_CC_SWREQ_HWR_CONNECTED
| AT_XDMAC_CC_DSYNC_MEM2PER
| AT_XDMAC_CC_MBSIZE_SIXTEEN
| AT_XDMAC_CC_TYPE_PER_TRAN;
+ if (atxdmac->layout->sdif)
+ atchan->cfg |= AT_XDMAC_CC_DIF(atchan->perif) |
+ AT_XDMAC_CC_SIF(atchan->memif);
+
csize = ffs(atchan->sconfig.dst_maxburst) - 1;
if (csize < 0) {
dev_err(chan2dev(chan), "invalid src maxburst value\n");
@@ -866,10 +910,12 @@ at_xdmac_interleaved_queue_desc(struct dma_chan *chan,
* ERRATA: Even if useless for memory transfers, the PERID has to not
* match the one of another channel. If not, it could lead to spurious
* flag status.
+ * For SAMA7G5x case, the SIF and DIF fields are no longer used.
+ * Thus, no need to have the SIF/DIF interfaces here.
+ * For SAMA5D4x and SAMA5D2x the SIF and DIF are already configured as
+ * zero.
*/
u32 chan_cc = AT_XDMAC_CC_PERID(0x7f)
- | AT_XDMAC_CC_DIF(0)
- | AT_XDMAC_CC_SIF(0)
| AT_XDMAC_CC_MBSIZE_SIXTEEN
| AT_XDMAC_CC_TYPE_MEM_TRAN;

@@ -1048,12 +1094,14 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
* ERRATA: Even if useless for memory transfers, the PERID has to not
* match the one of another channel. If not, it could lead to spurious
* flag status.
+ * For SAMA7G5x case, the SIF and DIF fields are no longer used.
+ * Thus, no need to have the SIF/DIF interfaces here.
+ * For SAMA5D4x and SAMA5D2x the SIF and DIF are already configured as
+ * zero.
*/
u32 chan_cc = AT_XDMAC_CC_PERID(0x7f)
| AT_XDMAC_CC_DAM_INCREMENTED_AM
| AT_XDMAC_CC_SAM_INCREMENTED_AM
- | AT_XDMAC_CC_DIF(0)
- | AT_XDMAC_CC_SIF(0)
| AT_XDMAC_CC_MBSIZE_SIXTEEN
| AT_XDMAC_CC_TYPE_MEM_TRAN;
unsigned long irqflags;
@@ -1154,12 +1202,14 @@ static struct at_xdmac_desc *at_xdmac_memset_create_desc(struct dma_chan *chan,
* ERRATA: Even if useless for memory transfers, the PERID has to not
* match the one of another channel. If not, it could lead to spurious
* flag status.
+ * For SAMA7G5x case, the SIF and DIF fields are no longer used.
+ * Thus, no need to have the SIF/DIF interfaces here.
+ * For SAMA5D4x and SAMA5D2x the SIF and DIF are already configured as
+ * zero.
*/
u32 chan_cc = AT_XDMAC_CC_PERID(0x7f)
| AT_XDMAC_CC_DAM_UBS_AM
| AT_XDMAC_CC_SAM_INCREMENTED_AM
- | AT_XDMAC_CC_DIF(0)
- | AT_XDMAC_CC_SIF(0)
| AT_XDMAC_CC_MBSIZE_SIXTEEN
| AT_XDMAC_CC_MEMSET_HW_MODE
| AT_XDMAC_CC_TYPE_MEM_TRAN;
@@ -1438,7 +1488,7 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
mask = AT_XDMAC_CC_TYPE | AT_XDMAC_CC_DSYNC;
value = AT_XDMAC_CC_TYPE_PER_TRAN | AT_XDMAC_CC_DSYNC_PER2MEM;
if ((desc->lld.mbr_cfg & mask) == value) {
- at_xdmac_write(atxdmac, AT_XDMAC_GSWF, atchan->mask);
+ at_xdmac_write(atxdmac, atxdmac->layout->gswf, atchan->mask);
while (!(at_xdmac_chan_read(atchan, AT_XDMAC_CIS) & AT_XDMAC_CIS_FIS))
cpu_relax();
}
@@ -1496,7 +1546,7 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
* FIFO flush ensures that data are really written.
*/
if ((desc->lld.mbr_cfg & mask) == value) {
- at_xdmac_write(atxdmac, AT_XDMAC_GSWF, atchan->mask);
+ at_xdmac_write(atxdmac, atxdmac->layout->gswf, atchan->mask);
while (!(at_xdmac_chan_read(atchan, AT_XDMAC_CIS) & AT_XDMAC_CIS_FIS))
cpu_relax();
}
@@ -1761,7 +1811,7 @@ static int at_xdmac_device_pause(struct dma_chan *chan)
return 0;

spin_lock_irqsave(&atchan->lock, flags);
- at_xdmac_write(atxdmac, AT_XDMAC_GRWS, atchan->mask);
+ at_xdmac_write(atxdmac, atxdmac->layout->grws, atchan->mask);
while (at_xdmac_chan_read(atchan, AT_XDMAC_CC)
& (AT_XDMAC_CC_WRIP | AT_XDMAC_CC_RDIP))
cpu_relax();
@@ -1784,7 +1834,7 @@ static int at_xdmac_device_resume(struct dma_chan *chan)
return 0;
}

- at_xdmac_write(atxdmac, AT_XDMAC_GRWR, atchan->mask);
+ at_xdmac_write(atxdmac, atxdmac->layout->grwr, atchan->mask);
clear_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
spin_unlock_irqrestore(&atchan->lock, flags);

@@ -1986,6 +2036,10 @@ static int at_xdmac_probe(struct platform_device *pdev)
atxdmac->regs = base;
atxdmac->irq = irq;

+ atxdmac->layout = of_device_get_match_data(&pdev->dev);
+ if (!atxdmac->layout)
+ return -ENODEV;
+
atxdmac->clk = devm_clk_get(&pdev->dev, "dma_clk");
if (IS_ERR(atxdmac->clk)) {
dev_err(&pdev->dev, "can't get dma_clk\n");
@@ -2129,6 +2183,10 @@ static const struct dev_pm_ops atmel_xdmac_dev_pm_ops = {
static const struct of_device_id atmel_xdmac_dt_ids[] = {
{
.compatible = "atmel,sama5d4-dma",
+ .data = &at_xdmac_sama5d4_layout,
+ }, {
+ .compatible = "microchip,sama7g5-dma",
+ .data = &at_xdmac_sama7g5_layout,
}, {
/* sentinel */
}
--
2.25.1

Next message: Thomas Gleixner: "Re: [PATCH 5/5] task_work: use TIF_NOTIFY_SIGNAL if available"
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