Re: [PATCH v9 11/12] soc: mediatek: cmdq: add cmdq_dev_get_client_reg function

CK Hu
2019-06-27T06:37:12Z

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@mediatek.com>
> ---
> 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__ */