linux/drivers/media/dvb-frontends/m88ds3103.h
David Howells 0f91c9d6ba [media] TS2020: Calculate tuner gain correctly
The TS2020 and TS2022 tuners take an input from the demodulator indicating the
AGC setting on that component that is then used to influence the tuner's own
gain.  This should be taken into account when calculating the gain and signal
strength.

Further, the existing TS2020 driver miscalculates the signal strength as the
result of its calculations can exceed the storage capacity of the 16-bit word
used to return it to userspace.

To this end:

 (1) Add a callback function (->get_agc_pwm()) in the ts2020_config struct that
     the tuner can call to get the AGC PWM value from the demodulator.

 (2) Modify the TS2020 driver to calculate the gain according to Montage's
     specification with the adjustment that we produce a negative value and
     scale it to 0.001dB units (which is what the DVBv5 API will require):

     (a) Callback to the demodulator to retrieve the AGC PWM value and then
     	 turn that into Vagc for incorporation in the calculations.  If the
     	 callback is unset, assume a Vagc of 0.

     (b) Calculate the tuner gain from a combination of Vagc and the tuner's RF
     	 gain and baseband gain settings.

 (3) Turn this into a percentage signal strength as per Montage's
     specification for return to userspace with the DVBv3 API.

 (4) Provide a function in the M88DS3103 demodulator driver that can be used to
     get the AGC PWM value on behalf of the tuner.

 (5) The ts2020_config.get_agc_pwm function should be set by the code that
     stitches together the drivers for each card.

     For the DVBSky cards that use the M88DS3103 with the TS2020 or the TS2022,
     set the get_agc_pwm function to point to m88ds3103_get_agc_pwm.

I have tested this with a DVBSky S952 card which has an M88DS3103 and a TS2022.

Thanks to Montage for providing access to information about the workings of
these parts.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-06-10 11:10:27 -03:00

193 lines
4.7 KiB
C

/*
* Montage Technology M88DS3103/M88RS6000 demodulator driver
*
* Copyright (C) 2013 Antti Palosaari <crope@iki.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef M88DS3103_H
#define M88DS3103_H
#include <linux/dvb/frontend.h>
/*
* I2C address
* 0x68,
*/
/**
* struct m88ds3103_platform_data - Platform data for the m88ds3103 driver
* @clk: Clock frequency.
* @i2c_wr_max: Max bytes I2C adapter can write at once.
* @ts_mode: TS mode.
* @ts_clk: TS clock (KHz).
* @ts_clk_pol: TS clk polarity. 1-active at falling edge; 0-active at rising
* edge.
* @spec_inv: Input spectrum inversion.
* @agc: AGC configuration.
* @agc_inv: AGC polarity.
* @clk_out: Clock output.
* @envelope_mode: DiSEqC envelope mode.
* @lnb_hv_pol: LNB H/V pin polarity. 0: pin high set to VOLTAGE_18, pin low to
* set VOLTAGE_13. 1: pin high set to VOLTAGE_13, pin low to set VOLTAGE_18.
* @lnb_en_pol: LNB enable pin polarity. 0: pin high to disable, pin low to
* enable. 1: pin high to enable, pin low to disable.
* @get_dvb_frontend: Get DVB frontend.
* @get_i2c_adapter: Get I2C adapter.
*/
struct m88ds3103_platform_data {
u32 clk;
u16 i2c_wr_max;
#define M88DS3103_TS_SERIAL 0 /* TS output pin D0, normal */
#define M88DS3103_TS_SERIAL_D7 1 /* TS output pin D7 */
#define M88DS3103_TS_PARALLEL 2 /* TS Parallel mode */
#define M88DS3103_TS_CI 3 /* TS CI Mode */
u8 ts_mode:2;
u32 ts_clk;
u8 ts_clk_pol:1;
u8 spec_inv:1;
u8 agc;
u8 agc_inv:1;
#define M88DS3103_CLOCK_OUT_DISABLED 0
#define M88DS3103_CLOCK_OUT_ENABLED 1
#define M88DS3103_CLOCK_OUT_ENABLED_DIV2 2
u8 clk_out:2;
u8 envelope_mode:1;
u8 lnb_hv_pol:1;
u8 lnb_en_pol:1;
struct dvb_frontend* (*get_dvb_frontend)(struct i2c_client *);
struct i2c_adapter* (*get_i2c_adapter)(struct i2c_client *);
/* private: For legacy media attach wrapper. Do not set value. */
u8 attach_in_use:1;
};
/*
* Do not add new m88ds3103_attach() users! Use I2C bindings instead.
*/
struct m88ds3103_config {
/*
* I2C address
* Default: none, must set
* 0x68, ...
*/
u8 i2c_addr;
/*
* clock
* Default: none, must set
* 27000000
*/
u32 clock;
/*
* max bytes I2C provider is asked to write at once
* Default: none, must set
* 33, 65, ...
*/
u16 i2c_wr_max;
/*
* TS output mode
* Default: M88DS3103_TS_SERIAL
*/
#define M88DS3103_TS_SERIAL 0 /* TS output pin D0, normal */
#define M88DS3103_TS_SERIAL_D7 1 /* TS output pin D7 */
#define M88DS3103_TS_PARALLEL 2 /* TS Parallel mode */
#define M88DS3103_TS_CI 3 /* TS CI Mode */
u8 ts_mode;
/*
* TS clk in KHz
* Default: 0.
*/
u32 ts_clk;
/*
* TS clk polarity.
* Default: 0. 1-active at falling edge; 0-active at rising edge.
*/
u8 ts_clk_pol:1;
/*
* spectrum inversion
* Default: 0
*/
u8 spec_inv:1;
/*
* AGC polarity
* Default: 0
*/
u8 agc_inv:1;
/*
* clock output
* Default: M88DS3103_CLOCK_OUT_DISABLED
*/
#define M88DS3103_CLOCK_OUT_DISABLED 0
#define M88DS3103_CLOCK_OUT_ENABLED 1
#define M88DS3103_CLOCK_OUT_ENABLED_DIV2 2
u8 clock_out;
/*
* DiSEqC envelope mode
* Default: 0
*/
u8 envelope_mode:1;
/*
* AGC configuration
* Default: none, must set
*/
u8 agc;
/*
* LNB H/V pin polarity
* Default: 0.
* 1: pin high set to VOLTAGE_13, pin low to set VOLTAGE_18.
* 0: pin high set to VOLTAGE_18, pin low to set VOLTAGE_13.
*/
u8 lnb_hv_pol:1;
/*
* LNB enable pin polarity
* Default: 0.
* 1: pin high to enable, pin low to disable.
* 0: pin high to disable, pin low to enable.
*/
u8 lnb_en_pol:1;
};
#if defined(CONFIG_DVB_M88DS3103) || \
(defined(CONFIG_DVB_M88DS3103_MODULE) && defined(MODULE))
extern struct dvb_frontend *m88ds3103_attach(
const struct m88ds3103_config *config,
struct i2c_adapter *i2c,
struct i2c_adapter **tuner_i2c);
extern int m88ds3103_get_agc_pwm(struct dvb_frontend *fe, u8 *_agc_pwm);
#else
static inline struct dvb_frontend *m88ds3103_attach(
const struct m88ds3103_config *config,
struct i2c_adapter *i2c,
struct i2c_adapter **tuner_i2c)
{
pr_warn("%s: driver disabled by Kconfig\n", __func__);
return NULL;
}
#define m88ds3103_get_agc_pwm NULL
#endif
#endif