linux-kernel - Re: [PATCH v5 3/9] media: adv748x: reduce amount of code for bitwise modifications of device registers

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Date:   Fri, 3 Apr 2020 20:09:34 +0100
From:   Kieran Bingham <kieran.bingham@...asonboard.com>
To:     Alex Riesen <alexander.riesen@...itec.com>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Hans Verkuil <hverkuil-cisco@...all.nl>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Kuninori Morimoto <kuninori.morimoto.gx@...esas.com>,
        devel@...verdev.osuosl.org, linux-media@...r.kernel.org,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
        linux-renesas-soc@...r.kernel.org
Subject: Re: [PATCH v5 3/9] media: adv748x: reduce amount of code for bitwise
 modifications of device registers

Hi Alex,

On 02/04/2020 19:34, Alex Riesen wrote:
> The regmap provides a convenient utility for this.
> The hdmi_* and dpll_* register modification macros added for symmetry
> with the existing operations (io_*, sdp_*).


Ah yes, perhaps I should have done that when I converted this driver to
regmap :-) (although looking at the history I think that was
pre-submission of the driver, so it's all a long time ago anyway).

This also should prevent the issues we solved in 0d962e061a (media: i2c:
adv748x: Fix unsafe macros), so I think it's still a good move.

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@...asonboard.com>


> Signed-off-by: Alexander Riesen <alexander.riesen@...itec.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>
> 
> --
> v3: remove _update name in favor of existing _clrset
> ---
>  drivers/media/i2c/adv748x/adv748x-core.c |  6 ++++++
>  drivers/media/i2c/adv748x/adv748x.h      | 14 +++++++++++---
>  2 files changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/i2c/adv748x/adv748x-core.c b/drivers/media/i2c/adv748x/adv748x-core.c
> index 5c59aad319d1..8580e6624276 100644
> --- a/drivers/media/i2c/adv748x/adv748x-core.c
> +++ b/drivers/media/i2c/adv748x/adv748x-core.c
> @@ -133,6 +133,12 @@ static int adv748x_write_check(struct adv748x_state *state, u8 page, u8 reg,
>  	return *error;
>  }
>  
> +int adv748x_update_bits(struct adv748x_state *state, u8 page, u8 reg, u8 mask,
> +			u8 value)
> +{
> +	return regmap_update_bits(state->regmap[page], reg, mask, value);
> +}
> +
>  /* adv748x_write_block(): Write raw data with a maximum of I2C_SMBUS_BLOCK_MAX
>   * size to one or more registers.
>   *
> diff --git a/drivers/media/i2c/adv748x/adv748x.h b/drivers/media/i2c/adv748x/adv748x.h
> index 09aab4138c3f..0a9d78c2870b 100644
> --- a/drivers/media/i2c/adv748x/adv748x.h
> +++ b/drivers/media/i2c/adv748x/adv748x.h
> @@ -393,25 +393,33 @@ int adv748x_write(struct adv748x_state *state, u8 page, u8 reg, u8 value);
>  int adv748x_write_block(struct adv748x_state *state, int client_page,
>  			unsigned int init_reg, const void *val,
>  			size_t val_len);
> +int adv748x_update_bits(struct adv748x_state *state, u8 page, u8 reg,
> +			u8 mask, u8 value);
>  
>  #define io_read(s, r) adv748x_read(s, ADV748X_PAGE_IO, r)
>  #define io_write(s, r, v) adv748x_write(s, ADV748X_PAGE_IO, r, v)
> -#define io_clrset(s, r, m, v) io_write(s, r, (io_read(s, r) & ~(m)) | (v))
> +#define io_clrset(s, r, m, v) adv748x_update_bits(s, ADV748X_PAGE_IO, r, m, v)
>  
>  #define hdmi_read(s, r) adv748x_read(s, ADV748X_PAGE_HDMI, r)
>  #define hdmi_read16(s, r, m) (((hdmi_read(s, r) << 8) | hdmi_read(s, (r)+1)) & (m))
>  #define hdmi_write(s, r, v) adv748x_write(s, ADV748X_PAGE_HDMI, r, v)
> +#define hdmi_clrset(s, r, m, v) \
> +	adv748x_update_bits(s, ADV748X_PAGE_HDMI, r, m, v)
> +
> +#define dpll_read(s, r) adv748x_read(s, ADV748X_PAGE_DPLL, r)
> +#define dpll_clrset(s, r, m, v) \
> +	adv748x_update_bits(s, ADV748X_PAGE_DPLL, r, m, v)
>  
>  #define repeater_read(s, r) adv748x_read(s, ADV748X_PAGE_REPEATER, r)
>  #define repeater_write(s, r, v) adv748x_write(s, ADV748X_PAGE_REPEATER, r, v)
>  
>  #define sdp_read(s, r) adv748x_read(s, ADV748X_PAGE_SDP, r)
>  #define sdp_write(s, r, v) adv748x_write(s, ADV748X_PAGE_SDP, r, v)
> -#define sdp_clrset(s, r, m, v) sdp_write(s, r, (sdp_read(s, r) & ~(m)) | (v))
> +#define sdp_clrset(s, r, m, v) adv748x_update_bits(s, ADV748X_PAGE_SDP, r, m, v)
>  
>  #define cp_read(s, r) adv748x_read(s, ADV748X_PAGE_CP, r)
>  #define cp_write(s, r, v) adv748x_write(s, ADV748X_PAGE_CP, r, v)
> -#define cp_clrset(s, r, m, v) cp_write(s, r, (cp_read(s, r) & ~(m)) | (v))
> +#define cp_clrset(s, r, m, v) adv748x_update_bits(s, ADV748X_PAGE_CP, r, m, v)
>  
>  #define tx_read(t, r) adv748x_read(t->state, t->page, r)
>  #define tx_write(t, r, v) adv748x_write(t->state, t->page, r, v)
> 

-- 
Regards
--
Kieran