Re: [RESEND, PATCH v13 11/12] soc: mediatek: cmdq: add cmdq_dev_get_client_reg function

[Bibby Hsieh <bibby.hsieh@mediatek.com>]

On Fri, 2019-08-23 at 16:21 +0200, Matthias Brugger wrote:
> 
> On 20/08/2019 10:49, Bibby Hsieh wrote:
> > GCE cannot know the register base address, this function
> > can help cmdq client to get the cmdq_client_reg structure.
> > 
> > Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
> > Reviewed-by: CK Hu <ck.hu@mediatek.com>
> > ---
> >  drivers/soc/mediatek/mtk-cmdq-helper.c | 29 ++++++++++++++++++++++++++
> >  include/linux/soc/mediatek/mtk-cmdq.h  | 21 +++++++++++++++++++
> >  2 files changed, 50 insertions(+)
> > 
> > diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > index c53f8476c68d..80f75a1075b4 100644
> > --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> > +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > @@ -27,6 +27,35 @@ struct cmdq_instruction {
> >  	u8 op;
> >  };
> >  
> > +int cmdq_dev_get_client_reg(struct device *dev,
> > +			    struct cmdq_client_reg *client_reg, int idx)
> > +{
> 
> Can't we do/call this in cmdq_mbox_create parsing the number of gce-client-reg
> properties we have and allocating these using a pointer to cmdq_client_reg in
> cmdq_client?
> We will have to free the pointer then in cmdq_mbox_destroy.
> 
> Regards,
> Matthias

I don't think we need to keep the cmdq_client_reg in cmdq_client
structure.
Because our client will have own data structure, they will copy the
client_reg information into their own structure.

In the design now, we do not allocate the cmdq_client_reg, client pass
the cmdq_client_reg pointer into this API.
Client will destroy the pointer after they get the information they
want.

Thanks for the comments so much.

Bibby

> 
> > +	struct of_phandle_args spec;
> > +	int err;
> > +
> > +	if (!client_reg)
> > +		return -ENOENT;
> > +
> > +	err = of_parse_phandle_with_fixed_args(dev->of_node,
> > +					       "mediatek,gce-client-reg",
> > +					       3, idx, &spec);
> > +	if (err < 0) {
> > +		dev_err(dev,
> > +			"error %d can't parse gce-client-reg property (%d)",
> > +			err, idx);
> > +
> > +		return err;
> > +	}
> > +
> > +	client_reg->subsys = (u8)spec.args[0];
> > +	client_reg->offset = (u16)spec.args[1];
> > +	client_reg->size = (u16)spec.args[2];
> > +	of_node_put(spec.np);
> > +
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(cmdq_dev_get_client_reg);
> > +
> >  static void cmdq_client_timeout(struct timer_list *t)
> >  {
> >  	struct cmdq_client *client = from_timer(client, t, timer);
> > diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
> > index a345870a6d10..02ddd60b212f 100644
> > --- a/include/linux/soc/mediatek/mtk-cmdq.h
> > +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> > @@ -15,6 +15,12 @@
> >  
> >  struct cmdq_pkt;
> >  
> > +struct cmdq_client_reg {
> > +	u8 subsys;
> > +	u16 offset;
> > +	u16 size;
> > +};
> > +
> >  struct cmdq_client {
> >  	spinlock_t lock;
> >  	u32 pkt_cnt;
> > @@ -24,6 +30,21 @@ struct cmdq_client {
> >  	u32 timeout_ms; /* in unit of microsecond */
> >  };
> >  
> > +/**
> > + * cmdq_dev_get_client_reg() - parse cmdq client reg from the device
> > + *			       node of CMDQ client
> > + * @dev:	device of CMDQ mailbox client
> > + * @client_reg: CMDQ client reg pointer
> > + * @idx:	the index of desired reg
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + *
> > + * Help CMDQ client parsing the cmdq client reg
> > + * from the device node of CMDQ client.
> > + */
> > +int cmdq_dev_get_client_reg(struct device *dev,
> > +			    struct cmdq_client_reg *client_reg, int idx);
> > +
> >  /**
> >   * cmdq_mbox_create() - create CMDQ mailbox client and channel
> >   * @dev:	device of CMDQ mailbox client
> >