linux-kernel - Re: [v2,5/6] reset-controller: ti: Introduce force-update method

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Date:   Tue, 04 Aug 2020 09:03:35 +0200
From:   Philipp Zabel <p.zabel@...gutronix.de>
To:     Crystal Guo <crystal.guo@...iatek.com>, robh+dt@...nel.org,
        matthias.bgg@...il.com
Cc:     srv_heupstream@...iatek.com, linux-mediatek@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        seiya.wang@...iatek.com, stanley.chu@...iatek.com,
        yingjoe.chen@...iatek.com, fan.chen@...iatek.com,
        yong.liang@...iatek.com, Suman Anna <s-anna@...com>,
        "Andrew F. Davis" <afd@...com>
Subject: Re: [v2,5/6] reset-controller: ti: Introduce force-update method

Hi Crystal,

On Mon, 2020-08-03 at 14:15 +0800, Crystal Guo wrote:
> Introduce force-update method for assert and deassert interface,
> which force the write operation in case the read already happens
> to return the correct value.
> 
> Signed-off-by: Crystal Guo <crystal.guo@...iatek.com>

Added Suman and Andrew for confirmation: I think writing unconditionally
can't break any existing user. Just changing to regmap_write_bits()
instead of adding the update-force property as in v1 should be fine.

regards
Philipp

> ---
>  drivers/reset/reset-ti-syscon.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/reset/reset-ti-syscon.c b/drivers/reset/reset-ti-syscon.c
> index 1c74bcb9a6c3..f4baf78afd14 100644
> --- a/drivers/reset/reset-ti-syscon.c
> +++ b/drivers/reset/reset-ti-syscon.c
> @@ -57,6 +57,7 @@ struct ti_syscon_reset_data {
>  	struct ti_syscon_reset_control *controls;
>  	unsigned int nr_controls;
>  	bool assert_deassert_together;
> +	bool update_force;
>  };
>  
>  #define to_ti_syscon_reset_data(rcdev)	\
> @@ -90,7 +91,10 @@ static int ti_syscon_reset_assert(struct reset_controller_dev *rcdev,
>  	mask = BIT(control->assert_bit);
>  	value = (control->flags & ASSERT_SET) ? mask : 0x0;
>  
> -	return regmap_update_bits(data->regmap, control->assert_offset, mask, value);
> +	if (data->update_force)
> +		return regmap_write_bits(data->regmap, control->assert_offset, mask, value);
> +	else
> +		return regmap_update_bits(data->regmap, control->assert_offset, mask, value);
>  }
>  
>  /**
> @@ -121,7 +125,10 @@ static int ti_syscon_reset_deassert(struct reset_controller_dev *rcdev,
>  	mask = BIT(control->deassert_bit);
>  	value = (control->flags & DEASSERT_SET) ? mask : 0x0;
>  
> -	return regmap_update_bits(data->regmap, control->deassert_offset, mask, value);
> +	if (data->update_force)
> +		return regmap_write_bits(data->regmap, control->deassert_offset, mask, value);
> +	else
> +		return regmap_update_bits(data->regmap, control->deassert_offset, mask, value);
>  }
>  
>  /**
> @@ -223,6 +230,10 @@ static int ti_syscon_reset_probe(struct platform_device *pdev)
>  		data->assert_deassert_together = true;
>  	else
>  		data->assert_deassert_together = false;
> +	if (of_property_read_bool(np, "update-force"))
> +		data->update_force = true;
> +	else
> +		data->update_force = false;
>  
>  	data->rcdev.ops = &ti_syscon_reset_ops;
>  	data->rcdev.owner = THIS_MODULE;
> -- 
> 2.18.0