OpenRTX/platform/drivers/baseband/SKY72310.c

119 wiersze
3.9 KiB
C

/***************************************************************************
* Copyright (C) 2020 by Silvano Seva IU2KWO and Niccolò Izzo IU2KIN *
* *
* 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 3 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. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#include <interfaces/gpio.h>
#include <interfaces/delays.h>
#include <hwconfig.h>
#include <math.h>
#include "SKY72310.h"
#define REF_CLK 16800000.0F /* Reference clock: 16.8MHz */
#define PHD_GAIN 0x1F /* Phase detector gain: hex value, max 0x1F */
void _spiSend(uint16_t value)
{
uint16_t temp = value;
gpio_clearPin(PLL_CS);
delayUs(10);
for(uint8_t i = 0; i < 16; i++)
{
gpio_setPin(PLL_CLK);
delayUs(1);
if(temp & 0x8000)
{
gpio_setPin(PLL_DAT);
}
else
{
gpio_clearPin(PLL_DAT);
}
temp <<= 1;
delayUs(1);
gpio_clearPin(PLL_CLK);
delayUs(1);
}
gpio_setPin(PLL_CLK);
delayUs(10);
gpio_setPin(PLL_CS);
}
void SKY73210_init()
{
gpio_setMode(PLL_CLK, OUTPUT);
gpio_setMode(PLL_DAT, OUTPUT);
gpio_setMode(PLL_CS, OUTPUT);
gpio_setPin(PLL_CS);
gpio_setMode(PLL_LD, INPUT);
_spiSend(0x6000 | ((uint16_t) PHD_GAIN)); /* Phase detector gain */
_spiSend(0x73D0); /* Power down/multiplexer control register */
_spiSend(0x8000); /* Modulation control register */
_spiSend(0x9000); /* Modulation data register */
}
void SKY73210_terminate()
{
gpio_setMode(PLL_CLK, INPUT);
gpio_setMode(PLL_DAT, INPUT);
gpio_setMode(PLL_CS, INPUT);
}
void SKY73210_setFrequency(float freq, uint8_t clkDiv)
{
/* Maximum allowable value for reference clock divider is 32 */
if (clkDiv > 32) clkDiv = 32;
float K = freq/(REF_CLK/((float) clkDiv));
float Ndiv = floor(K) - 32.0;
float Ndnd = round(262144*(K - Ndiv - 32.0));
/*
* With PLL in fractional mode, dividend range is [-131017 +131071].
* When converting from float to uint32_t we have to cast the value to a
* signed 18-bit one and increment the divider by one if dividend is negative.
*/
uint32_t dnd = ((uint32_t) Ndnd) & 0x03FFFF;
if(dnd & 0x20000) Ndiv += 1;
uint16_t dndMsb = dnd >> 8;
uint16_t dndLsb = dnd & 0x00FF;
_spiSend((uint16_t) Ndiv); /* Divider register */
_spiSend(0x2000 | dndLsb); /* Dividend LSB register */
_spiSend(0x1000 | dndMsb); /* Dividend MSB register */
_spiSend(0x5000 | ((uint16_t)clkDiv - 1)); /* Reference clock divider */
}
bool SKY73210_isPllLocked()
{
return (gpio_readPin(PLL_LD) == 1) ? true : false;
}
bool SKY73210_spiInUse()
{
/* If PLL chip select is low, SPI is being used by this driver. */
return (gpio_readPin(PLL_CS) == 1) ? false : true;
}