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

Dennis-YC Hsieh
2019-12-12T01:31:21Z

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 <dennis-yc.hsieh@mediatek.com>
> > ---
> > 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