Re: [PATCH 03/16] soundwire: cadence: add interface to check clock status

[Vinod Koul]

On 11-03-20, 13:41, Pierre-Louis Bossart wrote:
> From: Rander Wang <rander.wang@xxxxxxxxx>
> 
> If master is in clock stop state, driver can't modify registers
> in master except the registers for clock stop setting.
> 
> Signed-off-by: Rander Wang <rander.wang@xxxxxxxxx>
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> ---
>  drivers/soundwire/cadence_master.c | 19 +++++++++++++++++++
>  drivers/soundwire/cadence_master.h |  2 ++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
> index 941809ea00a8..71cba2585151 100644
> --- a/drivers/soundwire/cadence_master.c
> +++ b/drivers/soundwire/cadence_master.c
> @@ -1207,6 +1207,25 @@ static const struct sdw_master_port_ops cdns_port_ops = {
>  	.dpn_port_enable_ch = cdns_port_enable,
>  };
>  
> +/**
> + * sdw_cdns_is_clock_stop: Check clock status
> + *
> + * @cdns: Cadence instance
> + */
> +bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns)
> +{
> +	u32 status;
> +
> +	status = cdns_readl(cdns, CDNS_MCP_STAT) & CDNS_MCP_STAT_CLK_STOP;
> +	if (status) {
> +		dev_dbg(cdns->dev, "Clock is stopped\n");
> +		return true;
> +	}

This can be further optimized to:

        return !!(cdns_readl(cdns, CDNS_MCP_STAT) & CDNS_MCP_STAT_CLK_STOP);

-- 
~Vinod