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

Walker Chen walker.chen at starfivetech.com
Mon Feb 6 03:38:10 PST 2023


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

Signed-off-by: Walker Chen <walker.chen at starfivetech.com>
---
 .../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




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