[PATCH v1 2/3] dma: dw-axi-dmac: Add support for StarFive DMA

From: Walker Chen
Date: Mon Feb 06 2023 - 06:38:42 EST


Adding DMA reset operation in device probe, and using different
registers according to the hardware handshake number.

Signed-off-by: Walker Chen <walker.chen@xxxxxxxxxxxxxxxx>
---
.../dma/dw-axi-dmac/dw-axi-dmac-platform.c | 25 ++++++++++++++++---
drivers/dma/dw-axi-dmac/dw-axi-dmac.h | 3 +++
2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index a183d93bd7e2..3581810033d2 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -25,6 +25,7 @@
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
+#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/types.h>

@@ -86,7 +87,8 @@ static inline void axi_chan_config_write(struct axi_dma_chan *chan,

cfg_lo = (config->dst_multblk_type << CH_CFG_L_DST_MULTBLK_TYPE_POS |
config->src_multblk_type << CH_CFG_L_SRC_MULTBLK_TYPE_POS);
- if (chan->chip->dw->hdata->reg_map_8_channels) {
+ if (chan->chip->dw->hdata->reg_map_8_channels &&
+ !chan->chip->dw->hdata->use_cfg2) {
cfg_hi = config->tt_fc << CH_CFG_H_TT_FC_POS |
config->hs_sel_src << CH_CFG_H_HS_SEL_SRC_POS |
config->hs_sel_dst << CH_CFG_H_HS_SEL_DST_POS |
@@ -541,8 +543,6 @@ static void dw_axi_dma_set_hw_channel(struct axi_dma_chan *chan, bool set)
(chan->id * DMA_APB_HS_SEL_BIT_SIZE));
reg_value |= (val << (chan->id * DMA_APB_HS_SEL_BIT_SIZE));
lo_hi_writeq(reg_value, chip->apb_regs + DMAC_APB_HW_HS_SEL_0);
-
- return;
}

/*
@@ -1136,7 +1136,7 @@ static int dma_chan_terminate_all(struct dma_chan *dchan)
axi_chan_disable(chan);

ret = readl_poll_timeout_atomic(chan->chip->regs + DMAC_CHEN, val,
- !(val & chan_active), 1000, 10000);
+ !(val & chan_active), 1000, DMAC_TIMEOUT_US);
if (ret == -ETIMEDOUT)
dev_warn(dchan2dev(dchan),
"%s failed to stop\n", axi_chan_name(chan));
@@ -1323,6 +1323,12 @@ static int parse_device_properties(struct axi_dma_chip *chip)

chip->dw->hdata->m_data_width = tmp;

+ ret = device_property_read_u32(dev, "snps,num-hs-if", &tmp);
+ if (!ret) {
+ if (tmp > 16)
+ chip->dw->hdata->use_cfg2 = true;
+ }
+
ret = device_property_read_u32_array(dev, "snps,block-size", carr,
chip->dw->hdata->nr_channels);
if (ret)
@@ -1410,6 +1416,16 @@ static int dw_probe(struct platform_device *pdev)
if (IS_ERR(chip->cfgr_clk))
return PTR_ERR(chip->cfgr_clk);

+ if (of_device_is_compatible(node, "starfive,axi-dma")) {
+ chip->resets = devm_reset_control_array_get_exclusive(&pdev->dev);
+ if (IS_ERR(chip->resets))
+ return PTR_ERR(chip->resets);
+
+ ret = reset_control_deassert(chip->resets);
+ if (ret)
+ return ret;
+ }
+
ret = parse_device_properties(chip);
if (ret)
return ret;
@@ -1554,6 +1570,7 @@ static const struct dev_pm_ops dw_axi_dma_pm_ops = {
static const struct of_device_id dw_dma_of_id_table[] = {
{ .compatible = "snps,axi-dma-1.01a" },
{ .compatible = "intel,kmb-axi-dma" },
+ { .compatible = "starfive,axi-dma" },
{}
};
MODULE_DEVICE_TABLE(of, dw_dma_of_id_table);
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
index e9d5eb0fd594..761d95691c02 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
@@ -21,6 +21,7 @@
#define DMAC_MAX_CHANNELS 16
#define DMAC_MAX_MASTERS 2
#define DMAC_MAX_BLK_SIZE 0x200000
+#define DMAC_TIMEOUT_US 200000

struct dw_axi_dma_hcfg {
u32 nr_channels;
@@ -33,6 +34,7 @@ struct dw_axi_dma_hcfg {
/* Register map for DMAX_NUM_CHANNELS <= 8 */
bool reg_map_8_channels;
bool restrict_axi_burst_len;
+ bool use_cfg2;
};

struct axi_dma_chan {
@@ -70,6 +72,7 @@ struct axi_dma_chip {
struct clk *core_clk;
struct clk *cfgr_clk;
struct dw_axi_dma *dw;
+ struct reset_control *resets;
};

/* LLI == Linked List Item */
--
2.17.1