Re: [PATCH v2 2/3] dmaengine: dw-axi-dmac: Add support for StarFive JH7110 DMA

Walker Chen
2023-02-27T09:28:07Z

On 2023/2/26 22:25, Emil Renner Berthing wrote:
> On Tue, 21 Feb 2023 at 15:04, Walker Chen <walker.chen@starfivetech.com> wrote:
>>
>> Add DMA reset operation in device probe and use different configuration
>> on CH_CFG registers according to compatible string.
>>
>> Signed-off-by: Walker Chen <walker.chen@starfivetech.com>
>> ---
>> .../dma/dw-axi-dmac/dw-axi-dmac-platform.c | 19 +++++++++++++++++--
>> drivers/dma/dw-axi-dmac/dw-axi-dmac.h | 3 +++
>> 2 files changed, 20 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..858c4337650f 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 |
>> @@ -1142,7 +1144,7 @@ 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));
>> @@ -1416,6 +1418,18 @@ 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,jh7110-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;
>> +
>> + chip->dw->hdata->use_cfg2 = true;
>> + }
>> +
>
> In the future it would be great to use match data rather than all the
> calls to of_device_is_compatible.

Thanks, about this point, I will follow your advice.

>
>> ret = parse_device_properties(chip);
>> if (ret)
>> return ret;
>> @@ -1560,6 +1574,7 @@ 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,jh7110-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;
>
> This added field only seems to be written, but not read from anywhere.

Reset initialization will be encapsulated in match data.

> With that fixed:
>
> Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>

Thanks for your review and comment very much!

Best regards,
Walker