linux-kernel - Re: [PATCH v3 1/2] si2168: Set TS clock mode and frequency

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Message-ID: <20180704131532.628ee1c6@coco.lan>
Date:   Wed, 4 Jul 2018 13:15:32 -0300
From:   Mauro Carvalho Chehab <mchehab+samsung@...nel.org>
To:     Thomas Hollstegge <thomas.hollstegge@...il.com>
Cc:     linux-media@...r.kernel.org, Antti Palosaari <crope@....fi>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Sean Young <sean@...s.org>,
        Hans Verkuil <hans.verkuil@...co.com>,
        Stefan Brüns <stefan.bruens@...h-aachen.de>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 1/2] si2168: Set TS clock mode and frequency

Em Sat, 12 May 2018 20:24:58 +0200
Thomas Hollstegge <thomas.hollstegge@...il.com> escreveu:

> Some devices require a higher TS clock frequency to demodulate some
> muxes. This adds two optional parameters to control the TS clock
> frequency mode as well as the frequency.
> 
> Signed-off-by: Thomas Hollstegge <thomas.hollstegge@...il.com>
> ---
>  drivers/media/dvb-frontends/si2168.c      | 20 +++++++++++++++++++-
>  drivers/media/dvb-frontends/si2168.h      |  8 ++++++++
>  drivers/media/dvb-frontends/si2168_priv.h |  2 ++
>  3 files changed, 29 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c
> index 324493e..b05e677 100644
> --- a/drivers/media/dvb-frontends/si2168.c
> +++ b/drivers/media/dvb-frontends/si2168.c
> @@ -92,13 +92,15 @@ static int si2168_ts_bus_ctrl(struct dvb_frontend *fe, int acquire)
>  	dev_dbg(&client->dev, "%s acquire: %d\n", __func__, acquire);
>  
>  	/* set TS_MODE property */
> -	memcpy(cmd.args, "\x14\x00\x01\x10\x10\x00", 6);
> +	memcpy(cmd.args, "\x14\x00\x01\x10\x00\x00", 6);
>  	if (acquire)
>  		cmd.args[4] |= dev->ts_mode;
>  	else
>  		cmd.args[4] |= SI2168_TS_TRISTATE;
>  	if (dev->ts_clock_gapped)
>  		cmd.args[4] |= 0x40;
> +	cmd.args[4] |= (dev->ts_clock_mode & 0x03) << 4;
> +


Hmm... looking at this patch and on the next one, it seems that the
clock mode is either 1 (AUTO) or 2 (MANUAL), right?

If so, I would just do, instead:

	if (dev->ts_clock_freq)
		cmd.args[4] = SI2168_TS_CLOCK_MODE_AUTO_ADAPT << 4;
	else
		cmd.args[4] = SI2168_TS_CLOCK_MODE_MANUAL << 4;

And get rid of dev->ts_clock_mode parameter.

That seems more error-prune, as just specifying ts_clock_freq is
enough for the driver to do the right thing.

>  	cmd.wlen = 6;
>  	cmd.rlen = 4;
>  	ret = si2168_cmd_execute(client, &cmd);
> @@ -398,6 +400,18 @@ static int si2168_set_frontend(struct dvb_frontend *fe)
>  	if (ret)
>  		goto err;
>  
> +	/* set TS frequency */
> +	if (dev->ts_clock_freq) {
> +		memcpy(cmd.args, "\x14\x00\x0d\x10", 4);
> +		cmd.args[4] = ((dev->ts_clock_freq / 10000) >> 0) & 0xff;
> +		cmd.args[5] = ((dev->ts_clock_freq / 10000) >> 8) & 0xff;
> +		cmd.wlen = 6;
> +		cmd.rlen = 4;
> +		ret = si2168_cmd_execute(client, &cmd);
> +		if (ret)
> +			goto err;
> +	}
> +
>  	memcpy(cmd.args, "\x14\x00\x08\x10\xd7\x05", 6);
>  	cmd.args[5] |= dev->ts_clock_inv ? 0x00 : 0x10;
>  	cmd.wlen = 6;
> @@ -806,6 +820,10 @@ static int si2168_probe(struct i2c_client *client,
>  	dev->ts_mode = config->ts_mode;
>  	dev->ts_clock_inv = config->ts_clock_inv;
>  	dev->ts_clock_gapped = config->ts_clock_gapped;
> +	dev->ts_clock_mode = config->ts_clock_mode;
> +	if (dev->ts_clock_mode == 0)
> +		dev->ts_clock_mode = SI2168_TS_CLOCK_MODE_AUTO_ADAPT;
> +	dev->ts_clock_freq = config->ts_clock_freq;
>  	dev->spectral_inversion = config->spectral_inversion;
>  
>  	dev_info(&client->dev, "Silicon Labs Si2168-%c%d%d successfully identified\n",
> diff --git a/drivers/media/dvb-frontends/si2168.h b/drivers/media/dvb-frontends/si2168.h
> index d519edd..3f52ee8 100644
> --- a/drivers/media/dvb-frontends/si2168.h
> +++ b/drivers/media/dvb-frontends/si2168.h
> @@ -47,6 +47,14 @@ struct si2168_config {
>  	/* TS clock gapped */
>  	bool ts_clock_gapped;
>  
> +	/* TS clock mode */
> +#define SI2168_TS_CLOCK_MODE_AUTO_ADAPT	0x01
> +#define SI2168_TS_CLOCK_MODE_MANUAL	0x02
> +	u8 ts_clock_mode;
> +
> +	/* TS clock frequency (for manual mode) */
> +	u32 ts_clock_freq;
> +
>  	/* Inverted spectrum */
>  	bool spectral_inversion;
>  };
> diff --git a/drivers/media/dvb-frontends/si2168_priv.h b/drivers/media/dvb-frontends/si2168_priv.h
> index 2d362e1..8173d6c 100644
> --- a/drivers/media/dvb-frontends/si2168_priv.h
> +++ b/drivers/media/dvb-frontends/si2168_priv.h
> @@ -48,6 +48,8 @@ struct si2168_dev {
>  	u8 ts_mode;
>  	bool ts_clock_inv;
>  	bool ts_clock_gapped;
> +	u8 ts_clock_mode;
> +	u32 ts_clock_freq;
>  	bool spectral_inversion;
>  };
>  



Thanks,
Mauro