Subject: Re: [PATCH v2 08/14] soc: mediatek: cmdq: add write_s function

From: Dennis-YC Hsieh <[email-masked]>
Date: Thu, 12 Dec 2019 09:31:03 +0800

Hi CK,

On Tue, 2019-12-10 at 13:18 +0800, CK Hu wrote:
> Hi, Dennis:
> 
> On Wed, 2019-11-27 at 09:58 +0800, 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 <[email-masked]>
> > ---
> >  drivers/soc/mediatek/mtk-cmdq-helper.c   | 40 ++++++++++++++++++++++++
> >  include/linux/mailbox/mtk-cmdq-mailbox.h |  2 ++
> >  include/linux/soc/mediatek/mtk-cmdq.h    | 12 +++++++
> >  3 files changed, 54 insertions(+)
> > 
> > diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > index 9cc234f08ec5..2edbc0954d97 100644
> > --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> > +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > @@ -15,11 +15,18 @@
> >  #define CMDQ_EOC_CMD		((u64)((CMDQ_CODE_EOC << CMDQ_OP_CODE_SHIFT)) \
> >  				<< 32 | CMDQ_EOC_IRQ_EN)
> >  #define CMDQ_REG_TYPE		1
> > +#define CMDQ_ADDR_HIGH(addr)	((u32)(((addr) >> 16) & GENMASK(31, 0)))
> > +#define CMDQ_ADDR_LOW_BIT	BIT(1)
> > +#define CMDQ_ADDR_LOW(addr)	((u16)(addr) | CMDQ_ADDR_LOW_BIT)
> >  
> >  struct cmdq_instruction {
> >  	union {
> >  		u32 value;
> >  		u32 mask;
> > +		struct {
> > +			u16 arg_c;
> > +			u16 arg_b;
> > +		};
> >  	};
> >  	union {
> >  		u16 offset;
> > @@ -224,6 +231,39 @@ 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, phys_addr_t addr, u16 reg_idx,
> > +		     u32 mask)
> > +{
> > +	struct cmdq_instruction inst = { {0} };
> > +	const u16 dst_reg_idx = CMDQ_SPR_TEMP;
> > +	int err;
> > +
> > +	if (mask != U32_MAX) {
> > +		inst.op = CMDQ_CODE_MASK;
> > +		inst.mask = ~mask;
> > +		err = cmdq_pkt_append_command(pkt, inst);
> > +		if (err < 0)
> > +			return err;
> > +
> > +		inst.mask = 0;
> > +		inst.op = CMDQ_CODE_WRITE_S_MASK;
> > +	} else {
> > +		inst.op = CMDQ_CODE_WRITE_S;
> > +	}
> > +
> > +	err = cmdq_pkt_assign(pkt, dst_reg_idx, CMDQ_ADDR_HIGH(addr));
> 
> You combine assign and write_s in this function, so you always occupy
> register CMDQ_SPR_TEMP for this purpose, client could not use
> CMDQ_SPR_TEMP for other purpose. So I would like you just do write_s in
> this function. So the code in client would be:
> 
> cmdq_pkt_assign(pkt, high_addr_reg_idx, CMDQ_ADDR_HIGH(addr));
> cmdq_pkt_write_s(pkt, high_addr_reg_idx, CMDQ_ADDR_LOW(addr),
> src_reg_idx, mask);
> 
> Let client to decide which register for high address.
> 
> Another benefit of not combining instruction is that client driver owner
> would be more clear about which command is in command buffer and it's
> easier for them to debug.
> 

ok, i will expose reg idx as parameter

> > +	if (err < 0)
> > +		return err;
> > +
> > +	inst.arg_b_t = CMDQ_REG_TYPE;
> > +	inst.sop = dst_reg_idx;
> > +	inst.offset = CMDQ_ADDR_LOW(addr);
> > +	inst.arg_b = reg_idx;
> 
> I seems arg_b has a meaningful name.
> 
> Regards,
> CK
> 

ok, will change name

Regards,
Dennis

> > +
> > +	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..8ef87e1bd03b 100644
> > --- a/include/linux/mailbox/mtk-cmdq-mailbox.h
> > +++ b/include/linux/mailbox/mtk-cmdq-mailbox.h
> > @@ -59,6 +59,8 @@ enum cmdq_code {
> >  	CMDQ_CODE_JUMP = 0x10,
> >  	CMDQ_CODE_WFE = 0x20,
> >  	CMDQ_CODE_EOC = 0x40,
> > +	CMDQ_CODE_WRITE_S = 0x90,
> > +	CMDQ_CODE_WRITE_S_MASK = 0x91,
> >  	CMDQ_CODE_LOGIC = 0xa0,
> >  };
> >  
> > diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
> > index c66b3a0da2a2..56ff1970197c 100644
> > --- a/include/linux/soc/mediatek/mtk-cmdq.h
> > +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> > @@ -106,6 +106,18 @@ int cmdq_pkt_write(struct cmdq_pkt *pkt, u8 subsys, u16 offset, u32 value);
> >  int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u8 subsys,
> >  			u16 offset, u32 value, u32 mask);
> >  
> > +/**
> > + * cmdq_pkt_write_s_mask() - append write_s command to the CMDQ packet
> > + * @pkt:	the CMDQ packet
> > + * @addr:	the physical address of register or dma
> > + * @reg_idx:	the CMDQ internal register ID which cache source value
> > + * @mask:	the specified target register mask
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + */
> > +int cmdq_pkt_write_s(struct cmdq_pkt *pkt, phys_addr_t addr, u16 reg_idx,
> > +		     u32 mask);
> > +
> >  /**
> >   * cmdq_pkt_wfe() - append wait for event command to the CMDQ packet
> >   * @pkt:	the CMDQ packet
> 
> 

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