Re: [PATCH v6 2/4] dmaengine: dw-axi-dmac: Add support for StarFive JH7110 DMA

Vinod Koul
2023-03-31T12:04:32Z

On 22-03-23, 17:48, Walker Chen wrote:
> Add DMA reset operation in device probe and use different configuration
> on CH_CFG registers according to match data. Update all uses of
> of_device_is_compatible with of_device_get_match_data.
>
> Signed-off-by: Walker Chen <walker.chen@starfivetech.com>
> ---
> .../dma/dw-axi-dmac/dw-axi-dmac-platform.c | 38 ++++++++++++++++---
> drivers/dma/dw-axi-dmac/dw-axi-dmac.h | 1 +
> 2 files changed, 34 insertions(+), 5 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 4169e1d7d5ca..6cfcb541d8c3 100644
> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> @@ -21,10 +21,12 @@
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/of.h>
> +#include <linux/of_device.h>
> #include <linux/of_dma.h>
> #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>
>
> @@ -46,6 +48,10 @@
> DMA_SLAVE_BUSWIDTH_32_BYTES | \
> DMA_SLAVE_BUSWIDTH_64_BYTES)
>
> +#define AXI_DMA_FLAG_HAS_APB_REGS BIT(0)
> +#define AXI_DMA_FLAG_HAS_RESETS BIT(1)
> +#define AXI_DMA_FLAG_USE_CFG2 BIT(2)
> +
> static inline void
> axi_dma_iowrite32(struct axi_dma_chip *chip, u32 reg, u32 val)
> {
> @@ -86,7 +92,8 @@ 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) {

I think this will break existing users..

This is set for reg_map_8_channels && use_cfg2, latter being set only
for new controller, so what about existing users of these bits?

> 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 |
> @@ -1367,10 +1374,11 @@ static int parse_device_properties(struct axi_dma_chip *chip)
>
> static int dw_probe(struct platform_device *pdev)
> {
> - struct device_node *node = pdev->dev.of_node;
> struct axi_dma_chip *chip;
> struct dw_axi_dma *dw;
> struct dw_axi_dma_hcfg *hdata;
> + struct reset_control *resets;
> + unsigned int flags;
> u32 i;
> int ret;
>
> @@ -1398,12 +1406,25 @@ static int dw_probe(struct platform_device *pdev)
> if (IS_ERR(chip->regs))
> return PTR_ERR(chip->regs);
>
> - if (of_device_is_compatible(node, "intel,kmb-axi-dma")) {
> + flags = (uintptr_t)of_device_get_match_data(&pdev->dev);
> + if (flags & AXI_DMA_FLAG_HAS_APB_REGS) {
> chip->apb_regs = devm_platform_ioremap_resource(pdev, 1);
> if (IS_ERR(chip->apb_regs))
> return PTR_ERR(chip->apb_regs);
> }
>
> + if (flags & AXI_DMA_FLAG_HAS_RESETS) {
> + resets = devm_reset_control_array_get_exclusive(&pdev->dev);
> + if (IS_ERR(resets))
> + return PTR_ERR(resets);
> +
> + ret = reset_control_deassert(resets);
> + if (ret)
> + return ret;
> + }
> +
> + chip->dw->hdata->use_cfg2 = !!(flags & AXI_DMA_FLAG_USE_CFG2);
> +
> chip->core_clk = devm_clk_get(chip->dev, "core-clk");
> if (IS_ERR(chip->core_clk))
> return PTR_ERR(chip->core_clk);
> @@ -1554,8 +1575,15 @@ 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 = "snps,axi-dma-1.01a"
> + }, {
> + .compatible = "intel,kmb-axi-dma",
> + .data = (void *)AXI_DMA_FLAG_HAS_APB_REGS,
> + }, {
> + .compatible = "starfive,jh7110-axi-dma",
> + .data = (void *)(AXI_DMA_FLAG_HAS_RESETS | AXI_DMA_FLAG_USE_CFG2),
> + },
> {}
> };
> 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..eb267cb24f67 100644
> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
> @@ -33,6 +33,7 @@ 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 {
> --
> 2.17.1

--
~Vinod