Re: [PATCH 1/2] mn88473: calculate the IF register values

[Antti Palosaari <crope@iki.fi>]

On 01/13/2015 01:23 AM, Benjamin Larsson wrote:
> Add xtal as a configuration parameter so it can be used
> in the IF register value calculation. If not set in the
> configuration then use a default value.
>
> Signed-off-by: Benjamin Larsson <benjamin@southpole.se>

Reviewed-by: Antti Palosaari <crope@iki.fi>

Antti

> ---
>   drivers/media/dvb-frontends/mn88473.h        |  6 ++++++
>   drivers/staging/media/mn88473/mn88473.c      | 26 +++++++++++---------------
>   drivers/staging/media/mn88473/mn88473_priv.h |  1 +
>   3 files changed, 18 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/media/dvb-frontends/mn88473.h b/drivers/media/dvb-frontends/mn88473.h
> index a373ec9..c717ebed 100644
> --- a/drivers/media/dvb-frontends/mn88473.h
> +++ b/drivers/media/dvb-frontends/mn88473.h
> @@ -33,6 +33,12 @@ struct mn88473_config {
>   	 * DVB frontend.
>   	 */
>   	struct dvb_frontend **fe;
> +
> +	/*
> +	 * Xtal frequency.
> +	 * Hz
> +	 */
> +	u32 xtal;
>   };
>
>   #endif
> diff --git a/drivers/staging/media/mn88473/mn88473.c b/drivers/staging/media/mn88473/mn88473.c
> index 1659335..b65e519 100644
> --- a/drivers/staging/media/mn88473/mn88473.c
> +++ b/drivers/staging/media/mn88473/mn88473.c
> @@ -30,6 +30,7 @@ static int mn88473_set_frontend(struct dvb_frontend *fe)
>   	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
>   	int ret, i;
>   	u32 if_frequency;
> +	u64 tmp;
>   	u8 delivery_system_val, if_val[3], bw_val[7];
>
>   	dev_dbg(&client->dev,
> @@ -63,15 +64,12 @@ static int mn88473_set_frontend(struct dvb_frontend *fe)
>   	case SYS_DVBT2:
>   		if (c->bandwidth_hz <= 6000000) {
>   			/* IF 3570000 Hz, BW 6000000 Hz */
> -			memcpy(if_val, "\x24\x8e\x8a", 3);
>   			memcpy(bw_val, "\xe9\x55\x55\x1c\x29\x1c\x29", 7);
>   		} else if (c->bandwidth_hz <= 7000000) {
>   			/* IF 4570000 Hz, BW 7000000 Hz */
> -			memcpy(if_val, "\x2e\xcb\xfb", 3);
>   			memcpy(bw_val, "\xc8\x00\x00\x17\x0a\x17\x0a", 7);
>   		} else if (c->bandwidth_hz <= 8000000) {
>   			/* IF 4570000 Hz, BW 8000000 Hz */
> -			memcpy(if_val, "\x2e\xcb\xfb", 3);
>   			memcpy(bw_val, "\xaf\x00\x00\x11\xec\x11\xec", 7);
>   		} else {
>   			ret = -EINVAL;
> @@ -80,7 +78,6 @@ static int mn88473_set_frontend(struct dvb_frontend *fe)
>   		break;
>   	case SYS_DVBC_ANNEX_A:
>   		/* IF 5070000 Hz, BW 8000000 Hz */
> -		memcpy(if_val, "\x33\xea\xb3", 3);
>   		memcpy(bw_val, "\xaf\x00\x00\x11\xec\x11\xec", 7);
>   		break;
>   	default:
> @@ -105,17 +102,12 @@ static int mn88473_set_frontend(struct dvb_frontend *fe)
>   		if_frequency = 0;
>   	}
>
> -	switch (if_frequency) {
> -	case 3570000:
> -	case 4570000:
> -	case 5070000:
> -		break;
> -	default:
> -		dev_err(&client->dev, "IF frequency %d not supported\n",
> -				if_frequency);
> -		ret = -EINVAL;
> -		goto err;
> -	}
> +	/* Calculate IF registers ( (1<<24)*IF / Xtal ) */
> +	tmp =  div_u64(if_frequency * (u64)(1<<24) + (dev->xtal / 2),
> +				   dev->xtal);
> +	if_val[0] = ((tmp >> 16) & 0xff);
> +	if_val[1] = ((tmp >>  8) & 0xff);
> +	if_val[2] = ((tmp >>  0) & 0xff);
>
>   	ret = regmap_write(dev->regmap[2], 0x05, 0x00);
>   	ret = regmap_write(dev->regmap[2], 0xfb, 0x13);
> @@ -352,6 +344,10 @@ static int mn88473_probe(struct i2c_client *client,
>   	}
>
>   	dev->i2c_wr_max = config->i2c_wr_max;
> +	if (!config->xtal)
> +		dev->xtal = 25000000;
> +	else
> +		dev->xtal = config->xtal;
>   	dev->client[0] = client;
>   	dev->regmap[0] = regmap_init_i2c(dev->client[0], &regmap_config);
>   	if (IS_ERR(dev->regmap[0])) {
> diff --git a/drivers/staging/media/mn88473/mn88473_priv.h b/drivers/staging/media/mn88473/mn88473_priv.h
> index 78af112..ef6f013 100644
> --- a/drivers/staging/media/mn88473/mn88473_priv.h
> +++ b/drivers/staging/media/mn88473/mn88473_priv.h
> @@ -31,6 +31,7 @@ struct mn88473_dev {
>   	u16 i2c_wr_max;
>   	fe_delivery_system_t delivery_system;
>   	bool warm; /* FW running */
> +	u32 xtal;
>   };
>
>   #endif
>

-- 
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