Diff: libs/spi.cpp

Revision:

2:1df0b61d3b5a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libs/spi.cpp	Fri Feb 28 18:52:52 2014 -0800
@@ -0,0 +1,244 @@
+#include "spi.h"
+
+#include "lpc17xx_clkpwr.h"
+#include "lpc17xx_pinsel.h"
+#include "lpc17xx_ssp.h"
+#include "lpc17xx_gpio.h"
+
+#include <stdio.h>
+
+SPI* SPI::isr_dispatch[N_SPI_INTERRUPT_ROUTINES];
+
+class DMA;
+
+SPI::SPI(PinName mosi, PinName miso, PinName sclk)
+{
+    this->mosi.port = (mosi >> 5) & 7;
+    this->mosi.pin = mosi & 0x1F;
+
+    this->miso.port = (miso >> 5) & 7;
+    this->miso.pin = miso & 0x1F;
+
+    this->sclk.port = (sclk >> 5) & 7;
+    this->sclk.pin = sclk & 0x1F;
+
+    FIO_SetDir(this->mosi.port, 1UL << this->mosi.pin, 1);
+    FIO_SetDir(this->miso.port, 1UL << this->miso.pin, 0);
+    FIO_SetDir(this->sclk.port, 1UL << this->sclk.pin, 1);
+
+    if (mosi == P0_9 && miso == P0_8 && sclk == P0_7)
+    {
+//         iprintf("SPI: using 0.7,0.8,0.9 with SSP1\n");
+        // SSP1 on 0.7,0.8,0.9
+        sspr = LPC_SSP1;
+        isr_dispatch[1] = this;
+
+        LPC_PINCON->PINSEL0 &= ~((3 << (7*2)) | (3 << (8*2)) | (3 << (9*2)));
+        LPC_PINCON->PINSEL0 |=  ((2 << (7*2)) | (2 << (8*2)) | (2 << (9*2)));
+
+        LPC_SC->PCLKSEL0 &= 0xFFCFFFFF;
+        LPC_SC->PCLKSEL0 |= 0x00100000;
+
+        LPC_SC->PCONP |= CLKPWR_PCONP_PCSSP1;
+    }
+    else if (mosi == P0_18 && miso == P0_17 && sclk == P0_15)
+    {
+//         iprintf("SPI: using 0.15,0.17,0.18 with SSP0\n");
+        // SSP0 on 0.15,0.16,0.17,0.18
+        sspr = LPC_SSP0;
+        isr_dispatch[0] = this;
+
+        LPC_PINCON->PINSEL0 &= ~(3 << (15*2));
+        LPC_PINCON->PINSEL0 |=  (2 << (15*2));
+        LPC_PINCON->PINSEL1 &= ~( (3 << ((17*2)&30)) | (3 << ((18*2)&30)) );
+        LPC_PINCON->PINSEL1 |=  ( (2 << ((17*2)&30)) | (2 << ((18*2)&30)) );
+
+        LPC_SC->PCLKSEL1 &= 0xFFFFF3FF;
+        LPC_SC->PCLKSEL1 |= 0x00000400;
+
+        LPC_SC->PCONP |= CLKPWR_PCONP_PCSSP0;
+    }
+    else if (mosi == P1_24 && miso == P1_23 && sclk == P1_20)
+    {
+//         iprintf("SPI: using 1.20,1.23,1.24 with SSP0\n");
+        // SSP0 on 1.20,1.23,1.24
+        sspr = LPC_SSP0;
+        isr_dispatch[0] = this;
+
+// //         LPC_PINCON->PINSEL3 &= 0xFFFC3CFF;
+//         LPC_PINCON->PINSEL3 |= 0x0003C300;
+
+//         LPC_PINCON->PINSEL3 &= ~( (3 << ((20*2)&30)) | (3 << ((23*2)&30)) | (3 << ((24*2)&30)) );
+        LPC_PINCON->PINSEL3 |=  ( (3 << ((20*2)&30)) | (3 << ((23*2)&30)) | (3 << ((24*2)&30)) );
+
+        LPC_SC->PCLKSEL1 &= 0xFFFFF3FF;
+        LPC_SC->PCLKSEL1 |= 0x00000400;
+
+        LPC_SC->PCONP |= CLKPWR_PCONP_PCSSP0;
+    }
+    else
+    {
+//         iprintf("SPI: using soft-SPI\n");
+        sspr = (LPC_SSP_TypeDef *) 0;
+    }
+
+    if (sspr) {
+        sspr->CR0 = SSP_DATABIT_8 |
+                    SSP_FRAME_SPI;
+        sspr->CR1 = SSP_MASTER_MODE;
+        frequency(10000);
+        sspr->CR1 |= SSP_CR1_SSP_EN;
+    }
+}
+
+SPI::~SPI()
+{
+    if (sspr == LPC_SSP0)
+        LPC_SC->PCONP &= CLKPWR_PCONP_PCSSP0;
+    else if (sspr == LPC_SSP1)
+        LPC_SC->PCONP &= CLKPWR_PCONP_PCSSP1;
+}
+
+void SPI::frequency(uint32_t f)
+{
+    // CCLK = 25MHz
+    // CPSR = 2 to 254, even only
+    // CR0[8:15] (SCR, 0..255) is a further prescale
+
+//     iprintf("SPI: frequency %lu:", f);
+    delay = 25000000 / f;
+    // f = 25MHz / (CPSR . [SCR + 1])
+    // CPSR . (SCR + 1) = 25MHz / f
+    // min freq is 25MHz / (254 * 256)
+    if (sspr) {
+        if (f < 385) {
+            sspr->CPSR = 254;
+            sspr->CR0 &= 0x00FF;
+            sspr->CR0 |= 255 << 8;
+        }
+        // max freq is 25MHz / (2 * 1)
+        else if (f > 12500000) {
+            sspr->CPSR = 2;
+            sspr->CR0 &= 0x00FF;
+        }
+        else {
+            sspr->CPSR = delay & 0xFE;
+            // CPSR . (SCR + 1) = f;
+            // (SCR + 1) = f / CPSR;
+            // SCR = (f / CPSR) - 1
+            sspr->CR0 &= 0x00FF;
+            sspr->CR0 |= (((delay / sspr->CPSR) - 1) & 0xFF) << 8;
+        }
+//         iprintf(" CPSR=%lu, CR0=%lu", sspr->CPSR, sspr->CR0);
+    }
+//    iprintf("\n");
+}
+
+void _delay(uint32_t ticks) {
+    for (;ticks;ticks--)
+        asm volatile("nop\n\t");
+}
+
+uint8_t SPI::write(uint8_t data)
+{
+//     _cs = 1;
+    uint8_t r = 0;
+//     iprintf("SPI: >0x%02X", data);
+    if (sspr) {
+        while ((sspr->SR & SSP_SR_TNF) == 0);
+        sspr->DR = data;
+        while ((sspr->SR & SSP_SR_RNE) == 0);
+        r = sspr->DR & 255;
+    }
+    else {
+        for (int i = 0; i < 8; i++) {
+            FIO_ClearValue(sclk.port, 1UL << sclk.pin);         // clock LOW
+
+            if (data & 0x80)                                    // WRITE
+                FIO_SetValue(mosi.port, 1UL << mosi.pin);
+            else
+                FIO_ClearValue(mosi.port, 1UL << mosi.pin);
+            data <<= 1;
+
+            _delay(delay >> 1);                                 // DELAY
+
+            FIO_SetValue(sclk.port, 1UL << sclk.pin);           // clock HIGH
+
+            _delay(delay >> 1);                                 // DELAY
+
+            r <<= 1;
+            if (FIO_ReadValue(miso.port) & (1UL << miso.pin))   // READ
+                r |= 1;
+        }
+        FIO_ClearValue(sclk.port, 1UL << sclk.pin);
+    }
+//     iprintf(" <0x%02X\n", r);
+    return r;
+}
+
+// TODO: timer feeds DMA feeds 0xFFs to card then we listen for responses using our interrupt
+// allow me to do something like:
+// disk.start_multi_write(int blocks, int blocksize, void *buffer);
+// enable_usb_isr();
+// [...]
+// usb_isr() {
+//    if (disk.buffer_in_use(void *buffer))
+//        return;
+//    usb_ep_read(buffer);
+//    if (buffer_full)
+//        disk.validate_buffer(buffer);
+//    if (disk.finished_transfer())
+//        disk.end_multi_write();
+// };
+
+bool SPI::can_DMA()
+{
+    return (sspr != NULL);
+}
+
+// int SPI::setup_DMA_rx(DMA_REG *dma)
+// {
+//     if (!sspr)
+//         return -1;
+//
+//     dma->DMACCControl = 0;
+//     dma->DMACCConfiguration = 0;
+//     if (sspr == LPC_SSP0)
+//         dma->DMACCConfiguration |= (GPDMA_CONN_SSP0_Rx << 6);
+//     if (sspr == LPC_SSP1)
+//         dma->DMACCConfiguration |= (GPDMA_CONN_SSP1_Rx << 6);
+//
+//     dma->DMACCConfiguration |= GPDMA_TRANSFERTYPE_M2P << 11;
+//     return 0;
+// }
+//
+// int SPI::start_DMA_rx(DMA_REG *dma)
+// {
+//     dma->DMACCConfiguration |=
+// }
+
+// int SPI::writeblock(uint8_t *block, int blocklen)
+// {
+//     static DMA *d = new DMA();
+//     d.sourceaddr(block);
+//     d.transferlength(blocklen);
+//     d.destinationperipheral(sspr);
+//     d.start();
+//     while (d.active());
+//     return blocklen;
+//     return 0;
+// }
+
+void SPI::irq()
+{
+}
+
+void SSP0_IRQHandler(void) {
+    if (SPI::isr_dispatch[0])
+        SPI::isr_dispatch[0]->irq();
+}
+
+void SSP1_IRQHandler(void) {
+    if (SPI::isr_dispatch[1])
+        (SPI::isr_dispatch[1])->irq();
+}