src/main/drivers/vtx_rtc6705_soft_spi.c

   1 /*
   2  * This file is part of Cleanflight and Betaflight.
   3  *
   4  * Cleanflight and Betaflight are free software. You can redistribute
   5  * this software and/or modify this software under the terms of the
   6  * GNU General Public License as published by the Free Software
   7  * Foundation, either version 3 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * Cleanflight and Betaflight are distributed in the hope that they
  11  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  12  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this software.
  17  *
  18  * If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <stdbool.h>
  22 #include <stdint.h>
  23
  24 #include "platform.h"
  25
  26 #if defined(USE_VTX_RTC6705_SOFTSPI)
  27
  28 #include "drivers/bus_spi.h"
  29 #include "drivers/io.h"
  30 #include "drivers/light_led.h"
  31 #include "drivers/time.h"
  32 #include "drivers/vtx_rtc6705.h"
  33
  34
  35 #define DP_5G_MASK                  0x7000
  36 #define PA5G_BS_MASK                0x0E00
  37 #define PA5G_PW_MASK                0x0180
  38 #define PD_Q5G_MASK                 0x0040
  39 #define QI_5G_MASK                  0x0038
  40 #define PA_BS_MASK                  0x0007
  41
  42 #define PA_CONTROL_DEFAULT          0x4FBD
  43
  44 #define RTC6705_SPICLK_ON()   IOHi(rtc6705ClkPin)
  45 #define RTC6705_SPICLK_OFF()  IOLo(rtc6705ClkPin)
  46
  47 #define RTC6705_SPIDATA_ON()  IOHi(rtc6705DataPin)
  48 #define RTC6705_SPIDATA_OFF() IOLo(rtc6705DataPin)
  49
  50 #define DISABLE_RTC6705()     IOHi(rtc6705CsnPin)
  51 #define ENABLE_RTC6705()      IOLo(rtc6705CsnPin)
  52
  53 static IO_t rtc6705DataPin = IO_NONE;
  54 static IO_t rtc6705CsnPin = IO_NONE;
  55 static IO_t rtc6705ClkPin = IO_NONE;
  56
  57
  58 bool rtc6705SoftSpiIOInit(const vtxIOConfig_t *vtxIOConfig, const IO_t csnPin)
  59 {
  60     rtc6705CsnPin  = csnPin;
  61
  62     rtc6705DataPin = IOGetByTag(vtxIOConfig->dataTag);
  63     rtc6705ClkPin  = IOGetByTag(vtxIOConfig->clockTag);
  64
  65     if (!(rtc6705DataPin && rtc6705ClkPin)) {
  66         return false;
  67     }
  68
  69     IOInit(rtc6705DataPin, OWNER_VTX_DATA, RESOURCE_SOFT_OFFSET);
  70     IOConfigGPIO(rtc6705DataPin, IOCFG_OUT_PP);
  71
  72     IOInit(rtc6705ClkPin, OWNER_VTX_CLK, RESOURCE_SOFT_OFFSET);
  73     IOConfigGPIO(rtc6705ClkPin, IOCFG_OUT_PP);
  74
  75     // Important: The order of GPIO configuration calls are critical to ensure that incorrect signals are not briefly sent to the VTX.
  76     // GPIO bit is enabled so here so the CS/LE pin output is not pulled low when the GPIO is set in output mode.
  77     DISABLE_RTC6705();
  78     IOInit(rtc6705CsnPin, OWNER_VTX_CS, RESOURCE_SOFT_OFFSET);
  79     IOConfigGPIO(rtc6705CsnPin, IOCFG_OUT_PP);
  80
  81     return true;
  82 }
  83
  84 static void rtc6705_write_register(uint8_t addr, uint32_t data)
  85 {
  86     ENABLE_RTC6705();
  87     delay(1);
  88     // send address
  89     for (int i = 0; i < 4; i++) {
  90         if ((addr >> i) & 1) {
  91             RTC6705_SPIDATA_ON();
  92         } else {
  93             RTC6705_SPIDATA_OFF();
  94         }
  95
  96         RTC6705_SPICLK_ON();
  97         delay(1);
  98         RTC6705_SPICLK_OFF();
  99         delay(1);
 100     }
 101     // Write bit
 102     RTC6705_SPIDATA_ON();
 103     RTC6705_SPICLK_ON();
 104     delay(1);
 105     RTC6705_SPICLK_OFF();
 106     delay(1);
 107     for (int i = 0; i < 20; i++) {
 108         if ((data >> i) & 1) {
 109             RTC6705_SPIDATA_ON();
 110         } else {
 111             RTC6705_SPIDATA_OFF();
 112         }
 113         RTC6705_SPICLK_ON();
 114         delay(1);
 115         RTC6705_SPICLK_OFF();
 116         delay(1);
 117     }
 118     DISABLE_RTC6705();
 119 }
 120
 121 void rtc6705SoftSpiSetFrequency(uint16_t channel_freq)
 122 {
 123     uint32_t freq = (uint32_t)channel_freq * 1000;
 124     freq /= 40;
 125     const uint32_t N = freq / 64;
 126     const uint32_t A = freq % 64;
 127     rtc6705_write_register(0, 400);
 128     rtc6705_write_register(1, (N << 7) | A);
 129 }
 130
 131 void rtc6705SoftSpiSetRFPower(uint8_t rf_power)
 132 {
 133     rtc6705_write_register(7, (rf_power > 1 ? PA_CONTROL_DEFAULT : (PA_CONTROL_DEFAULT | PD_Q5G_MASK) & (~(PA5G_PW_MASK | PA5G_BS_MASK))));
 134 }
 135 #endif