Re: [PATCH v3 2/3] dmaengine: dw-axi-dmac: Add support for StarFive JH7110 DMA

[Emil Renner Berthing]

On Mon, 27 Feb 2023 at 14:11, Walker Chen <walker.chen@xxxxxxxxxxxxxxxx> wrote:
>
> Add DMA reset operation in device probe and use different configuration
> on CH_CFG registers according to match data.
>
> Signed-off-by: Walker Chen <walker.chen@xxxxxxxxxxxxxxxx>
> Reviewed-by: Emil Renner Berthing <emil.renner.berthing@xxxxxxxxxxxxx>

Hi Walker,

Firstly your Signed-off-by should be the last line.

I may have been unclear in my last review, sorry. I meant to give my
reviewed-by if you just removed the reset pointer that was never used.
This new version also adds a lot of new code.

Though, I'm glad you want to update the driver to use match data
rather than of_device_is_compatible, but then please update all uses
of of_device_is_compatible. With this patch starfive uses match data
and the intel,kmb-axi-dma still uses of_device_is_compatible.

More comments below..

> ---
>  .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 34 +++++++++++++++++--
>  drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |  7 ++++
>  2 files changed, 39 insertions(+), 2 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 bf85aa0979ec..400eeef707bf 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>
>
> @@ -86,7 +88,8 @@ 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 |
> @@ -1142,7 +1145,7 @@ 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));
> @@ -1367,6 +1370,17 @@ static int parse_device_properties(struct axi_dma_chip *chip)
>         return 0;
>  }
>
> +static int jh7110_rst_init(struct platform_device *pdev)
> +{
> +       struct reset_control *resets;
> +
> +       resets = devm_reset_control_array_get_exclusive(&pdev->dev);
> +       if (IS_ERR(resets))
> +               return PTR_ERR(resets);
> +
> +       return reset_control_deassert(resets);
> +}
> +
>  static int dw_probe(struct platform_device *pdev)
>  {
>         struct device_node *node = pdev->dev.of_node;
> @@ -1374,6 +1388,7 @@ static int dw_probe(struct platform_device *pdev)
>         struct resource *mem;
>         struct dw_axi_dma *dw;
>         struct dw_axi_dma_hcfg *hdata;
> +       const struct axi_dma_chip_config *ccfg;
>         u32 i;
>         int ret;
>
> @@ -1416,6 +1431,15 @@ static int dw_probe(struct platform_device *pdev)
>         if (IS_ERR(chip->cfgr_clk))
>                 return PTR_ERR(chip->cfgr_clk);
>
> +       ccfg = of_device_get_match_data(&pdev->dev);
> +       if (ccfg) {
> +               ret = ccfg->rst_init(pdev);
> +               if (ret)
> +                       return ret;
> +
> +               chip->dw->hdata->use_cfg2 = ccfg->use_cfg2;
> +       }
> +
>         ret = parse_device_properties(chip);
>         if (ret)
>                 return ret;
> @@ -1557,9 +1581,15 @@ static const struct dev_pm_ops dw_axi_dma_pm_ops = {
>         SET_RUNTIME_PM_OPS(axi_dma_runtime_suspend, axi_dma_runtime_resume, NULL)
>  };
>
> +static const struct axi_dma_chip_config jh7110_chip_config = {
> +       .rst_init = jh7110_rst_init,
> +       .use_cfg2 = true,
> +};
> +
>  static const struct of_device_id dw_dma_of_id_table[] = {
>         { .compatible = "snps,axi-dma-1.01a" },
>         { .compatible = "intel,kmb-axi-dma" },
> +       { .compatible = "starfive,jh7110-axi-dma", .data = &jh7110_chip_config },
>         {}
>  };
>  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..7b404ae9a26a 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 {
> @@ -72,6 +74,11 @@ struct axi_dma_chip {
>         struct dw_axi_dma       *dw;
>  };
>
> +struct axi_dma_chip_config {
> +       int (*rst_init)(struct platform_device *pdev);

Please just spell reset in full, it's not that much longer.

> +       bool use_cfg2;
> +};
> +

This struct is only used in dw-axi-dmac-platform.c above, so no need
to add it here.

>  /* LLI == Linked List Item */
>  struct __packed axi_dma_lli {
>         __le64          sar;
> --
> 2.17.1
>