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circuitpython/ports/atmel-samd/samd21_peripherals.c

93 lines
3.0 KiB

/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2017 Dan Halbert for Adafruit Industries
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "hpl/gclk/hpl_gclk_base.h"
#include "hpl/pm/hpl_pm_base.h"
// The clock initializer values are rather random, so we need to put them in
// tables for lookup. We can't compute them.
static const uint8_t SERCOMx_GCLK_ID_CORE[] = {
SERCOM0_GCLK_ID_CORE,
SERCOM1_GCLK_ID_CORE,
SERCOM2_GCLK_ID_CORE,
SERCOM3_GCLK_ID_CORE,
#ifdef SERCOM4
SERCOM4_GCLK_ID_CORE,
#endif
#ifdef SERCOM5
SERCOM5_GCLK_ID_CORE,
#endif
};
static const uint8_t SERCOMx_GCLK_ID_SLOW[] = {
SERCOM0_GCLK_ID_SLOW,
SERCOM1_GCLK_ID_SLOW,
SERCOM2_GCLK_ID_SLOW,
SERCOM3_GCLK_ID_SLOW,
#ifdef SERCOM4
SERCOM4_GCLK_ID_SLOW,
#endif
#ifdef SERCOM5
SERCOM5_GCLK_ID_SLOW,
#endif
};
// Clock initialization as done in Atmel START.
void samd_peripherals_sercom_clock_init(Sercom* sercom, uint8_t sercom_index) {
_pm_enable_bus_clock(PM_BUS_APBC, sercom);
_gclk_enable_channel(SERCOMx_GCLK_ID_CORE[sercom_index], GCLK_CLKCTRL_GEN_GCLK0_Val);
_gclk_enable_channel(SERCOMx_GCLK_ID_SLOW[sercom_index], GCLK_CLKCTRL_GEN_GCLK3_Val);
}
// Figure out the DOPO value given the chosen clock pad and mosi pad.
// Return an out-of-range value (255) if the combination is not permitted.
// <0x0=>PAD[0,1]_DO_SCK
// <0x1=>PAD[2,3]_DO_SCK
// <0x2=>PAD[3,1]_DO_SCK
// <0x3=>PAD[0,3]_DO_SCK
uint8_t samd_peripherals_get_spi_dopo(uint8_t clock_pad, uint8_t mosi_pad) {
if (clock_pad == 1) {
if (mosi_pad == 0) {
return 0;
} else if (mosi_pad == 3) {
return 2;
}
} else if (clock_pad == 3) {
if (mosi_pad == 0) {
return 3;
} else if (mosi_pad == 2) {
return 1;
}
}
return 255;
}
bool samd_peripherals_valid_spi_clock_pad(uint8_t clock_pad) {
return clock_pad == 1 || clock_pad == 3;
}