Re: [PATCH v5 09/13] soc: mediatek: cmdq: add write_s value function

Matthias Brugger
2020-05-24T18:14:22Z

On 24/05/2020 19:31, Dennis-YC Hsieh wrote:
> Hi Matthias,
>
> Thanks for your comment.
>
> On Sat, 2020-05-16 at 20:20 +0200, Matthias Brugger wrote:
>>
>> On 08/03/2020 11:52, Dennis YC Hsieh wrote:
>>> add write_s function in cmdq helper functions which
>>> writes a constant value to address with large dma
>>> access support.
>>>
>>> Signed-off-by: Dennis YC Hsieh <dennis-yc.hsieh@mediatek.com>
>>> Reviewed-by: CK Hu <ck.hu@mediatek.com>
>>> ---
>>> drivers/soc/mediatek/mtk-cmdq-helper.c | 26 ++++++++++++++++++++++++++
>>> include/linux/soc/mediatek/mtk-cmdq.h | 14 ++++++++++++++
>>> 2 files changed, 40 insertions(+)
>>>
>>> diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
>>> index 03c129230cd7..a9ebbabb7439 100644
>>> --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
>>> +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
>>> @@ -269,6 +269,32 @@ int cmdq_pkt_write_s(struct cmdq_pkt *pkt, u16 high_addr_reg_idx,
>>> }
>>> EXPORT_SYMBOL(cmdq_pkt_write_s);
>>>
>>> +int cmdq_pkt_write_s_value(struct cmdq_pkt *pkt, u16 high_addr_reg_idx,
>>> + u16 addr_low, u32 value, u32 mask)
>>> +{
>>> + struct cmdq_instruction inst = { {0} };
>>> + 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.op = CMDQ_CODE_WRITE_S_MASK;
>>> + } else {
>>> + inst.op = CMDQ_CODE_WRITE_S;
>>> + }
>>> +
>>> + inst.sop = high_addr_reg_idx;
>>
>> Writing u16 value in a 5 bit wide variable?
>
> We need only 5 bits in this case. I'll change high_addr_reg_idx
> parameter to u8.
>

Ok, please make sure to mask the value, so that it's explicit in the code that
we only use the lowest 5 bits of high_addr_reg_idx.

Regards,
Matthias

>>
>>> + inst.offset = addr_low;
>>> + inst.value = value;
>>> +
>>> + return cmdq_pkt_append_command(pkt, inst);
>>> +}
>>> +EXPORT_SYMBOL(cmdq_pkt_write_s_value);
>>> +
>>> int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event)
>>> {
>>> struct cmdq_instruction inst = { {0} };
>>> diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
>>> index 01b4184af310..fec292aac83c 100644
>>> --- a/include/linux/soc/mediatek/mtk-cmdq.h
>>> +++ b/include/linux/soc/mediatek/mtk-cmdq.h
>>> @@ -135,6 +135,20 @@ int cmdq_pkt_read_s(struct cmdq_pkt *pkt, u16 high_addr_reg_idx, u16 addr_low,
>>> int cmdq_pkt_write_s(struct cmdq_pkt *pkt, u16 high_addr_reg_idx,
>>> u16 addr_low, u16 src_reg_idx, u32 mask);
>>>
>>> +/**
>>> + * cmdq_pkt_write_s_value() - append write_s command with mask to the CMDQ
>>> + * packet which write value to a physical address
>>> + * @pkt: the CMDQ packet
>>> + * @high_addr_reg_idx: internal regisger ID which contains high address of pa
>>
>> register
>
> will fix
>
>
> Regards,
> Dennis
>
>>
>>> + * @addr_low: low address of pa
>>> + * @value: the specified target value
>>> + * @mask: the specified target mask
>>> + *
>>> + * Return: 0 for success; else the error code is returned
>>> + */
>>> +int cmdq_pkt_write_s_value(struct cmdq_pkt *pkt, u16 high_addr_reg_idx,
>>> + u16 addr_low, u32 value, u32 mask);
>>> +
>>> /**
>>> * cmdq_pkt_wfe() - append wait for event command to the CMDQ packet
>>> * @pkt: the CMDQ packet
>>>