Re: [PATCH v1 03/11] soc: mediatek: cmdq: add write_s function

[Matthias Brugger]

On 21/06/2020 16:18, Dennis YC Hsieh wrote:
> add write_s function in cmdq helper functions which
> writes value contains in internal register to address
> with large dma access support.
> 
> Signed-off-by: Dennis YC Hsieh <dennis-yc.hsieh@xxxxxxxxxxxx>
> ---
>  drivers/soc/mediatek/mtk-cmdq-helper.c   |   19 +++++++++++++++++++
>  include/linux/mailbox/mtk-cmdq-mailbox.h |    1 +
>  include/linux/soc/mediatek/mtk-cmdq.h    |   19 +++++++++++++++++++
>  3 files changed, 39 insertions(+)
> 
> diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
> index bf32e3b2ca6c..817a5a97dbe5 100644
> --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> @@ -18,6 +18,10 @@ struct cmdq_instruction {
>  	union {
>  		u32 value;
>  		u32 mask;
> +		struct {
> +			u16 arg_c;
> +			u16 src_reg;
> +		};
>  	};
>  	union {
>  		u16 offset;
> @@ -222,6 +226,21 @@ int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u8 subsys,
>  }
>  EXPORT_SYMBOL(cmdq_pkt_write_mask);
>  
> +int cmdq_pkt_write_s(struct cmdq_pkt *pkt, u16 high_addr_reg_idx,
> +		     u16 addr_low, u16 src_reg_idx)
> +{

Do I understand correctly that we use CMDQ_ADDR_HIGH(addr) and
CMDQ_ADDR_LOW(addr) to calculate in the client high_addr_reg_idx and addr_low
respectively?

In that case I think a better interface would be to pass the address and do the
high/low calculation in the cmdq_pkt_write_s

Regards,
Matthias

> +	struct cmdq_instruction inst = {};
> +
> +	inst.op = CMDQ_CODE_WRITE_S;
> +	inst.src_t = CMDQ_REG_TYPE;
> +	inst.sop = high_addr_reg_idx;
> +	inst.offset = addr_low;
> +	inst.src_reg = src_reg_idx;
> +
> +	return cmdq_pkt_append_command(pkt, inst);
> +}
> +EXPORT_SYMBOL(cmdq_pkt_write_s);
> +
>  int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event)
>  {
>  	struct cmdq_instruction inst = { {0} };
> diff --git a/include/linux/mailbox/mtk-cmdq-mailbox.h b/include/linux/mailbox/mtk-cmdq-mailbox.h
> index 121c3bb6d3de..ee67dd3b86f5 100644
> --- a/include/linux/mailbox/mtk-cmdq-mailbox.h
> +++ b/include/linux/mailbox/mtk-cmdq-mailbox.h
> @@ -59,6 +59,7 @@ enum cmdq_code {
>  	CMDQ_CODE_JUMP = 0x10,
>  	CMDQ_CODE_WFE = 0x20,
>  	CMDQ_CODE_EOC = 0x40,
> +	CMDQ_CODE_WRITE_S = 0x90,
>  	CMDQ_CODE_LOGIC = 0xa0,
>  };
>  
> diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
> index 83340211e1d3..e1c5a7549b4f 100644
> --- a/include/linux/soc/mediatek/mtk-cmdq.h
> +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> @@ -12,6 +12,8 @@
>  #include <linux/timer.h>
>  
>  #define CMDQ_NO_TIMEOUT		0xffffffffu
> +#define CMDQ_ADDR_HIGH(addr)	((u32)(((addr) >> 16) & GENMASK(31, 0)))
> +#define CMDQ_ADDR_LOW(addr)	((u16)(addr) | BIT(1))
>  
>  struct cmdq_pkt;
>  
> @@ -103,6 +105,23 @@ int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u8 subsys,
>  			u16 offset, u32 value, u32 mask);
>  
>  /**
> + * cmdq_pkt_write_s() - append write_s command to the CMDQ packet
> + * @pkt:	the CMDQ packet
> + * @high_addr_reg_idx:	internal register ID which contains high address of pa
> + * @addr_low:	low address of pa
> + * @src_reg_idx:	the CMDQ internal register ID which cache source value
> + *
> + * Return: 0 for success; else the error code is returned
> + *
> + * Support write value to physical address without subsys. Use CMDQ_ADDR_HIGH()
> + * to get high address and call cmdq_pkt_assign() to assign value into internal
> + * reg. Also use CMDQ_ADDR_LOW() to get low address for addr_low parameter when
> + * call to this function.
> + */
> +int cmdq_pkt_write_s(struct cmdq_pkt *pkt, u16 high_addr_reg_idx,
> +		     u16 addr_low, u16 src_reg_idx);
> +
> +/**
>   * cmdq_pkt_wfe() - append wait for event command to the CMDQ packet
>   * @pkt:	the CMDQ packet
>   * @event:	the desired event type to "wait and CLEAR"
>