Hi, Bibby: On Thu, 2019-06-27 at 14:19 +0800, 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@xxxxxxxxxxxx> > --- > drivers/soc/mediatek/mtk-cmdq-helper.c | 24 ++++++++++++++++++++++++ > include/linux/soc/mediatek/mtk-cmdq.h | 21 +++++++++++++++++++++ > 2 files changed, 45 insertions(+) > > diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c > index 70ad4d806fac..ceb1b569891f 100644 > --- a/drivers/soc/mediatek/mtk-cmdq-helper.c > +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c > @@ -27,6 +27,30 @@ struct cmdq_instruction { > u8 op; > }; > > +int cmdq_dev_get_client_reg(struct device *dev, > + struct cmdq_client_reg *client_reg, int idx) > +{ > + struct of_phandle_args spec; > + > + if (!client_reg) > + return -ENOENT; > + > + if (of_parse_phandle_with_args(dev->of_node, "mediatek,gce-client-reg", > + "#subsys-cells", idx, &spec)) { > + dev_err(dev, "can't parse gce-client-reg property (%d)", idx); > + > + return -ENOENT; Maybe my expression is not so clear. of_parse_phandle_with_args() may return -ENOENT, but it also may return -EINVAL. My point is why do you change the return value of of_parse_phandle_with_args(). What the error you get from of_parse_phandle_with_args(), you could also return it to the caller of cmdq_dev_get_client_reg(). Regards, CK > + } > + > + client_reg->subsys = spec.args[0]; > + client_reg->offset = spec.args[1]; > + client_reg->size = 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..be402c4c740e 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; > @@ -142,4 +148,19 @@ int cmdq_pkt_flush_async(struct cmdq_pkt *pkt, cmdq_async_flush_cb cb, > */ > int cmdq_pkt_flush(struct cmdq_pkt *pkt); > > +/** > + * cmdq_dev_get_client_reg() - parse cmdq client reg from the device > + * node of CMDQ client > + * @dev: device of CMDQ mailbox clienti > + * @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 pasing 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); > + > #endif /* __MTK_CMDQ_H__ */