mirror of
https://github.com/fairwaves/UHD-Fairwaves.git
synced 2025-11-02 21:13:14 +00:00
111 lines
3.0 KiB
C
111 lines
3.0 KiB
C
/*
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* Copyright 2007,2008 Free Software Foundation, Inc.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "spi.h"
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#include "memory_map.h"
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#include "pic.h"
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#include "nonstdio.h"
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//void (*volatile spi_callback)(void); //SPI callback when xfer complete.
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//static void spi_irq_handler(unsigned irq);
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void
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spi_init(void)
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{
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/*
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* f_sclk = f_wb / ((div + 1) * 2)
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*/
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spi_regs->div = 1; // 0 = Div by 2 (25 MHz); 1 = Div-by-4 (12.5 MHz)
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}
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void
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spi_wait(void)
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{
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while (spi_regs->ctrl & SPI_CTRL_GO_BSY)
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;
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}
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uint32_t
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spi_transact(bool readback, int slave, uint32_t data, int length, uint32_t flags)
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{
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flags &= (SPI_CTRL_TXNEG | SPI_CTRL_RXNEG);
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int ctrl = SPI_CTRL_ASS | (SPI_CTRL_CHAR_LEN_MASK & length) | flags;
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spi_wait();
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// Tell it which SPI slave device to access
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spi_regs->ss = slave & 0xffff;
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// Data we will send
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spi_regs->txrx0 = data;
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// Run it -- write once and rewrite with GO set
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spi_regs->ctrl = ctrl;
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spi_regs->ctrl = ctrl | SPI_CTRL_GO_BSY;
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if(readback) {
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spi_wait();
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return spi_regs->txrx0;
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}
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else
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return 0;
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}
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/*
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void spi_register_callback(void (*volatile callback)(void)) {
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spi_callback = callback;
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}
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static void spi_irq_handler(unsigned irq) {
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// printf("SPI IRQ handler\n");
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// uint32_t wat = spi_regs->ctrl; //read a register just to clear the interrupt
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//spi_regs->ctrl &= ~SPI_CTRL_IE;
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if(spi_callback) spi_callback(); //we could just use the PIC to register the user's callback, but this provides the ability to do other things later
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}
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uint32_t spi_get_data(void) {
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return spi_regs->txrx0;
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}
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bool
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spi_async_transact(int slave, uint32_t data, int length, uint32_t flags, void (*volatile callback)(void)) {
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flags &= (SPI_CTRL_TXNEG | SPI_CTRL_RXNEG);
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int ctrl = SPI_CTRL_ASS | SPI_CTRL_IE | (SPI_CTRL_CHAR_LEN_MASK & length) | flags;
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if(spi_regs->ctrl & SPI_CTRL_GO_BSY) {
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printf("Async SPI busy!\n");
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return false; //we don't wait on busy, we just return failure. we count on the host to not set up another transaction before the last one finishes.
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}
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// Tell it which SPI slave device to access
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spi_regs->ss = slave & 0xffff;
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// Data we will send
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spi_regs->txrx0 = data;
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spi_register_callback(callback);
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pic_register_handler(IRQ_SPI, spi_irq_handler);
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// Run it -- write once and rewrite with GO set
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spi_regs->ctrl = ctrl;
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spi_regs->ctrl = ctrl | SPI_CTRL_GO_BSY;
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return true;
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}
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*/
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