src/libs/spi.cpp

   1 #include "spi.h"
   2
   3 #include "lpc17xx_clkpwr.h"
   4 #include "lpc17xx_pinsel.h"
   5 #include "lpc17xx_ssp.h"
   6 #include "lpc17xx_gpio.h"
   7
   8 #include <stdio.h>
   9
  10 SPI* SPI::isr_dispatch[N_SPI_INTERRUPT_ROUTINES];
  11
  12 class DMA;
  13
  14 SPI::SPI(PinName mosi, PinName miso, PinName sclk)
  15 {
  16     this->mosi.port = (mosi >> 5) & 7;
  17     this->mosi.pin = mosi & 0x1F;
  18
  19     this->miso.port = (miso >> 5) & 7;
  20     this->miso.pin = miso & 0x1F;
  21
  22     this->sclk.port = (sclk >> 5) & 7;
  23     this->sclk.pin = sclk & 0x1F;
  24
  25     FIO_SetDir(this->mosi.port, 1UL << this->mosi.pin, 1);
  26     FIO_SetDir(this->miso.port, 1UL << this->miso.pin, 0);
  27     FIO_SetDir(this->sclk.port, 1UL << this->sclk.pin, 1);
  28
  29     if (mosi == P0_9 && miso == P0_8 && sclk == P0_7)
  30     {
  31 //         iprintf("SPI: using 0.7,0.8,0.9 with SSP1\n");
  32         // SSP1 on 0.7,0.8,0.9
  33         sspr = LPC_SSP1;
  34         isr_dispatch[1] = this;
  35
  36         LPC_PINCON->PINSEL0 &= ~((3 << (7*2)) | (3 << (8*2)) | (3 << (9*2)));
  37         LPC_PINCON->PINSEL0 |=  ((2 << (7*2)) | (2 << (8*2)) | (2 << (9*2)));
  38
  39         LPC_SC->PCLKSEL0 &= 0xFFCFFFFF;
  40         LPC_SC->PCLKSEL0 |= 0x00100000;
  41
  42         LPC_SC->PCONP |= CLKPWR_PCONP_PCSSP1;
  43     }
  44     else if (mosi == P0_18 && miso == P0_17 && sclk == P0_15)
  45     {
  46 //         iprintf("SPI: using 0.15,0.17,0.18 with SSP0\n");
  47         // SSP0 on 0.15,0.16,0.17,0.18
  48         sspr = LPC_SSP0;
  49         isr_dispatch[0] = this;
  50
  51         LPC_PINCON->PINSEL0 &= ~(3 << (15*2));
  52         LPC_PINCON->PINSEL0 |=  (2 << (15*2));
  53         LPC_PINCON->PINSEL1 &= ~( (3 << ((17*2)&30)) | (3 << ((18*2)&30)) );
  54         LPC_PINCON->PINSEL1 |=  ( (2 << ((17*2)&30)) | (2 << ((18*2)&30)) );
  55
  56         LPC_SC->PCLKSEL1 &= 0xFFFFF3FF;
  57         LPC_SC->PCLKSEL1 |= 0x00000400;
  58
  59         LPC_SC->PCONP |= CLKPWR_PCONP_PCSSP0;
  60     }
  61     else if (mosi == P1_24 && miso == P1_23 && sclk == P1_20)
  62     {
  63 //         iprintf("SPI: using 1.20,1.23,1.24 with SSP0\n");
  64         // SSP0 on 1.20,1.23,1.24
  65         sspr = LPC_SSP0;
  66         isr_dispatch[0] = this;
  67
  68 // //         LPC_PINCON->PINSEL3 &= 0xFFFC3CFF;
  69 //         LPC_PINCON->PINSEL3 |= 0x0003C300;
  70
  71 //         LPC_PINCON->PINSEL3 &= ~( (3 << ((20*2)&30)) | (3 << ((23*2)&30)) | (3 << ((24*2)&30)) );
  72         LPC_PINCON->PINSEL3 |=  ( (3 << ((20*2)&30)) | (3 << ((23*2)&30)) | (3 << ((24*2)&30)) );
  73
  74         LPC_SC->PCLKSEL1 &= 0xFFFFF3FF;
  75         LPC_SC->PCLKSEL1 |= 0x00000400;
  76
  77         LPC_SC->PCONP |= CLKPWR_PCONP_PCSSP0;
  78     }
  79     else
  80     {
  81 //         iprintf("SPI: using soft-SPI\n");
  82         sspr = (LPC_SSP_TypeDef *) 0;
  83     }
  84
  85     if (sspr) {
  86         sspr->CR0 = SSP_DATABIT_8 |
  87                     SSP_FRAME_SPI;
  88         sspr->CR1 = SSP_MASTER_MODE;
  89         frequency(10000);
  90         sspr->CR1 |= SSP_CR1_SSP_EN;
  91     }
  92 }
  93
  94 SPI::~SPI()
  95 {
  96     if (sspr == LPC_SSP0)
  97         LPC_SC->PCONP &= CLKPWR_PCONP_PCSSP0;
  98     else if (sspr == LPC_SSP1)
  99         LPC_SC->PCONP &= CLKPWR_PCONP_PCSSP1;
 100 }
 101
 102 void SPI::frequency(uint32_t f)
 103 {
 104     // CCLK = 25MHz
 105     // CPSR = 2 to 254, even only
 106     // CR0[8:15] (SCR, 0..255) is a further prescale
 107
 108 //     iprintf("SPI: frequency %lu:", f);
 109     delay = 25000000 / f;
 110     // f = 25MHz / (CPSR . [SCR + 1])
 111     // CPSR . (SCR + 1) = 25MHz / f
 112     // min freq is 25MHz / (254 * 256)
 113     if (sspr) {
 114         if (f < 385) {
 115             sspr->CPSR = 254;
 116             sspr->CR0 &= 0x00FF;
 117             sspr->CR0 |= 255 << 8;
 118         }
 119         // max freq is 25MHz / (2 * 1)
 120         else if (f > 12500000) {
 121             sspr->CPSR = 2;
 122             sspr->CR0 &= 0x00FF;
 123         }
 124         else {
 125             sspr->CPSR = delay & 0xFE;
 126             // CPSR . (SCR + 1) = f;
 127             // (SCR + 1) = f / CPSR;
 128             // SCR = (f / CPSR) - 1
 129             sspr->CR0 &= 0x00FF;
 130             sspr->CR0 |= (((delay / sspr->CPSR) - 1) & 0xFF) << 8;
 131         }
 132 //         iprintf(" CPSR=%lu, CR0=%lu", sspr->CPSR, sspr->CR0);
 133     }
 134 //    iprintf("\n");
 135 }
 136
 137 void _delay(uint32_t ticks) {
 138     for (;ticks;ticks--)
 139         asm volatile("nop\n\t");
 140 }
 141
 142 uint8_t SPI::write(uint8_t data)
 143 {
 144 //     _cs = 1;
 145     uint8_t r = 0;
 146 //     iprintf("SPI: >0x%02X", data);
 147     if (sspr) {
 148         while ((sspr->SR & SSP_SR_TNF) == 0);
 149         sspr->DR = data;
 150         while ((sspr->SR & SSP_SR_RNE) == 0);
 151         r = sspr->DR & 255;
 152     }
 153     else {
 154         for (int i = 0; i < 8; i++) {
 155             FIO_ClearValue(sclk.port, 1UL << sclk.pin);         // clock LOW
 156
 157             if (data & 0x80)                                    // WRITE
 158                 FIO_SetValue(mosi.port, 1UL << mosi.pin);
 159             else
 160                 FIO_ClearValue(mosi.port, 1UL << mosi.pin);
 161             data <<= 1;
 162
 163             _delay(delay >> 1);                                 // DELAY
 164
 165             FIO_SetValue(sclk.port, 1UL << sclk.pin);           // clock HIGH
 166
 167             _delay(delay >> 1);                                 // DELAY
 168
 169             r <<= 1;
 170             if (FIO_ReadValue(miso.port) & (1UL << miso.pin))   // READ
 171                 r |= 1;
 172         }
 173         FIO_ClearValue(sclk.port, 1UL << sclk.pin);
 174     }
 175 //     iprintf(" <0x%02X\n", r);
 176     return r;
 177 }
 178
 179 // TODO: timer feeds DMA feeds 0xFFs to card then we listen for responses using our interrupt
 180 // allow me to do something like:
 181 // disk.start_multi_write(int blocks, int blocksize, void *buffer);
 182 // enable_usb_isr();
 183 // [...]
 184 // usb_isr() {
 185 //    if (disk.buffer_in_use(void *buffer))
 186 //        return;
 187 //    usb_ep_read(buffer);
 188 //    if (buffer_full)
 189 //        disk.validate_buffer(buffer);
 190 //    if (disk.finished_transfer())
 191 //        disk.end_multi_write();
 192 // };
 193
 194 bool SPI::can_DMA()
 195 {
 196     return (sspr != NULL);
 197 }
 198
 199 // int SPI::setup_DMA_rx(DMA_REG *dma)
 200 // {
 201 //     if (!sspr)
 202 //         return -1;
 203 //
 204 //     dma->DMACCControl = 0;
 205 //     dma->DMACCConfiguration = 0;
 206 //     if (sspr == LPC_SSP0)
 207 //         dma->DMACCConfiguration |= (GPDMA_CONN_SSP0_Rx << 6);
 208 //     if (sspr == LPC_SSP1)
 209 //         dma->DMACCConfiguration |= (GPDMA_CONN_SSP1_Rx << 6);
 210 //
 211 //     dma->DMACCConfiguration |= GPDMA_TRANSFERTYPE_M2P << 11;
 212 //     return 0;
 213 // }
 214 //
 215 // int SPI::start_DMA_rx(DMA_REG *dma)
 216 // {
 217 //     dma->DMACCConfiguration |=
 218 // }
 219
 220 // int SPI::writeblock(uint8_t *block, int blocklen)
 221 // {
 222 //     static DMA *d = new DMA();
 223 //     d.sourceaddr(block);
 224 //     d.transferlength(blocklen);
 225 //     d.destinationperipheral(sspr);
 226 //     d.start();
 227 //     while (d.active());
 228 //     return blocklen;
 229 //     return 0;
 230 // }
 231
 232 void SPI::irq()
 233 {
 234 }
 235
 236 void SSP0_IRQHandler(void) {
 237     if (SPI::isr_dispatch[0])
 238         SPI::isr_dispatch[0]->irq();
 239 }
 240
 241 void SSP1_IRQHandler(void) {
 242     if (SPI::isr_dispatch[1])
 243         (SPI::isr_dispatch[1])->irq();
 244 }