draft: mcu SPI-flash support

.gitignore

@@ -1,4 +1,5 @@
 *.o
+*.bin
 test/test
 test/test.bin
 tags

src/spi_drv.h

@@ -0,0 +1,11 @@
+#ifndef SPI_DRV_H_INCLUDED
+#define SPI_DRV_H_INCLUDED
+#include <stdint.h>
+
+void spi_init(int polarity, int phase);
+void spi_write(const char byte);
+uint8_t spi_read(void);
+void spi_cs_on(void);
+void spi_cs_off(void);
+
+#endif

src/spi_drv_stm32f4.c

@@ -0,0 +1,98 @@
+#include <stdint.h>
+#include "spi_drv.h"
+#include "system.h"
+
+void spi_cs_off(void)
+{
+    GPIOE_BSRR |= (1 << SPI_FLASH_PIN);
+    DMB();
+    while(!(GPIOE_ODR & (1 << SPI_FLASH_PIN)))
+        ;
+}
+
+void spi_cs_on(void)
+{
+    volatile int i;
+    GPIOE_BSRR |= (1 << (SPI_FLASH_PIN + 16));
+    DMB();
+    while(GPIOE_ODR & (1 << SPI_FLASH_PIN))
+        ;
+}
+
+
+static void spi_flash_pin_setup(void)
+{
+    uint32_t reg;
+    AHB1_CLOCK_ER |= GPIOE_AHB1_CLOCK_ER;
+    reg = GPIOE_MODE & ~ (0x03 << (SPI_FLASH_PIN * 2));
+    GPIOE_MODE = reg | (1 << (SPI_FLASH_PIN * 2));
+
+    reg = GPIOE_PUPD & (0x03 <<  (SPI_FLASH_PIN * 2));
+    GPIOE_PUPD = reg | (0x01 << (SPI_FLASH_PIN * 2));
+
+    reg = GPIOE_OSPD & ~(0x03 << (SPI_FLASH_PIN * 2));
+    GPIOE_OSPD |= (0x03 << (SPI_FLASH_PIN * 2));
+
+}
+
+static void spi1_pins_setup(void)
+{
+    uint32_t reg;
+    AHB1_CLOCK_ER |= GPIOB_AHB1_CLOCK_ER;
+    /* Set mode = AF */
+    reg = GPIOB_MODE & ~ (0x03 << (SPI1_CLOCK_PIN * 2));
+    GPIOB_MODE = reg | (2 << (SPI1_CLOCK_PIN * 2));
+    reg = GPIOB_MODE & ~ (0x03 << (SPI1_MOSI_PIN * 2));
+    GPIOB_MODE = reg | (2 << (SPI1_MOSI_PIN * 2));
+    reg = GPIOB_MODE & ~ (0x03 << (SPI1_MISO_PIN * 2));
+    GPIOB_MODE = reg | (2 << (SPI1_MISO_PIN * 2));
+
+    /* Alternate function: use low pins (5,6,7) */
+    reg = GPIOB_AFL & ~(0xf << ((SPI1_CLOCK_PIN) * 4));
+    GPIOB_AFL = reg | (SPI1_PIN_AF << ((SPI1_CLOCK_PIN) * 4));
+    reg = GPIOB_AFL & ~(0xf << ((SPI1_MOSI_PIN) * 4));
+    GPIOB_AFL = reg | (SPI1_PIN_AF << ((SPI1_MOSI_PIN) * 4));
+    reg = GPIOB_AFL & ~(0xf << ((SPI1_MISO_PIN) * 4));
+    GPIOB_AFL = reg | (SPI1_PIN_AF << ((SPI1_MISO_PIN) * 4));
+
+}
+
+static void spi1_reset(void)
+{
+    APB2_CLOCK_RST |= SPI1_APB2_CLOCK_ER_VAL;
+    APB2_CLOCK_RST &= ~SPI1_APB2_CLOCK_ER_VAL;
+}
+
+uint8_t spi_read(void)
+{
+    volatile uint32_t reg;
+    do {
+        reg = SPI1_SR;
+    } while(!(reg & SPI_SR_RX_NOTEMPTY));
+    return (uint8_t)SPI1_DR;
+}
+
+void spi_write(const char byte)
+{
+    int i;
+    volatile uint32_t reg;
+    do {
+        reg = SPI1_SR;
+    } while ((reg & SPI_SR_TX_EMPTY) == 0);
+    SPI1_DR = byte;
+    do {
+        reg = SPI1_SR;
+    } while ((reg & SPI_SR_TX_EMPTY) == 0);
+}
+
+
+void spi_init(int polarity, int phase)
+{
+    spi1_pins_setup();
+    spi_flash_pin_setup();
+    APB2_CLOCK_ER |= SPI1_APB2_CLOCK_ER_VAL;
+    spi1_reset();
+	SPI1_CR1 = SPI_CR1_MASTER | (5 << 3) | (polarity << 1) | (phase << 0);
+	SPI1_CR2 |= SPI_CR2_SSOE;
+    SPI1_CR1 |= SPI_CR1_SPI_EN;
+}

src/spi_flash.c

@@ -0,0 +1,247 @@
+#include "system.h"
+#include "spi_drv.h"
+
+#define SPI_FLASH_SECTOR_SIZE (4096)
+#define SPI_FLASH_PAGE_SIZE   (256)
+
+#define MDID            0x90
+#define RDSR            0x05
+#define WRSR            0x01
+#   define ST_BUSY (1 << 0)
+#   define ST_WEL  (1 << 1)
+#   define ST_BP0  (1 << 2)
+#   define ST_BP1  (1 << 3)
+#   define ST_BP2  (1 << 4)
+#   define ST_BP3  (1 << 5)
+#   define ST_AAI  (1 << 6)
+#   define ST_BRO  (1 << 7)
+#define WREN            0x06
+#define WRDI            0x04
+#define SECTOR_ERASE    0x20
+#define BYTE_READ       0x03
+#define BYTE_WRITE      0x02
+#define AUTOINC         0xAD
+#define EWSR            0x50
+#define EBSY            0x70
+#define DBSY            0x80
+
+
+static enum write_mode {
+    WB_WRITEPAGE = 0x00,
+    SST_AAI      = 0x01
+} chip_write_mode = WB_WRITEPAGE;
+
+static void write_address(uint32_t address)
+{
+    spi_write((address & 0xFF00) >> 8);
+    spi_read();
+    spi_write((address & 0xFF0000) >> 16);
+    spi_read();
+    spi_write((address & 0xFF000000) >> 24);
+    spi_read();
+}
+
+static uint8_t read_status(void)
+{
+    uint8_t status;
+    int i;
+    spi_cs_on();
+    spi_write(RDSR);
+    spi_read();
+    spi_write(0xFF);
+    status = spi_read();
+    spi_cs_off();
+    return status;
+}
+
+static void spi_cmd(uint8_t cmd)
+{
+    spi_cs_on();
+    spi_write(cmd);
+    spi_read();
+    spi_cs_off();
+}
+
+static inline void flash_aai_enable(void)
+{
+    spi_cmd(EBSY);
+}
+
+static inline void flash_aai_disable(void)
+{
+    spi_cmd(DBSY);
+}
+
+static void flash_write_enable(void)
+{
+    uint8_t status;
+    do {
+        spi_cmd(WREN);
+        status = read_status();
+    } while ((status & ST_WEL) == 0);
+}
+
+static void flash_write_disable(void)
+{
+    uint8_t status;
+    spi_cmd(WRDI);
+}
+static void wait_busy(void)
+{
+    uint8_t status;
+    do {
+        status = read_status();
+    } while(status & ST_BUSY);
+}
+
+static int spi_flash_write_page(uint32_t address, const void *data, int len)
+{
+    const uint8_t *buf = data;
+    int j = 0;
+    while (len > 0) {
+        wait_busy();
+        flash_write_enable();
+        spi_cs_on();
+        spi_write(BYTE_WRITE);
+        spi_read();
+        write_address(address);
+        do {
+            spi_write(buf[j++]);
+            address++;
+            spi_read();
+            len--;
+        } while ((address % SPI_FLASH_PAGE_SIZE) != 0);
+        spi_cs_off();
+    }
+    wait_busy();
+    return j;
+}
+
+static int spi_flash_write_aai(uint32_t address, const void *data, int len)
+{
+    const uint8_t *buf = data;
+    int j = 0;
+    int cont = 0;
+    wait_busy();
+    if (len < 1)
+        return -1;
+    while (len > 0) {
+        if ((address & 0x01) || (len < 2)) {
+            flash_write_enable();
+            spi_cs_on();
+            spi_write(BYTE_WRITE);
+            spi_read();
+            write_address(address);
+            spi_write(buf[j++]);
+            spi_read();
+            spi_cs_off();
+            len--;
+            address++;
+        } else {
+            if (!cont) {
+                flash_aai_enable();
+                flash_write_enable();
+            }
+            spi_cs_on();
+            spi_write(AUTOINC);
+            spi_read();
+            if (!cont) {
+                /* First AAI transaction, send address. */
+                write_address(address);
+                cont = 1;
+            }
+            spi_write(buf[j++]);
+            spi_read();
+            spi_write(buf[j++]);
+            spi_read();
+            spi_cs_off();
+            len -= 2;
+            address += 2;
+            read_status();
+        }
+    }
+    if (cont) {
+        flash_write_disable();
+        flash_aai_disable();
+    }
+    wait_busy();
+    return j;
+}
+
+/* --- */
+
+uint16_t spi_flash_probe(void)
+{
+    uint8_t manuf, product, b0;
+    int i;
+    wait_busy();
+    spi_cs_on();
+    spi_write(MDID);
+    b0 = spi_read();
+
+    write_address(0);
+    spi_write(0xFF);
+    manuf = spi_read();
+    spi_write(0xFF);
+    product = spi_read();
+    spi_cs_off();
+    if (manuf == 0xBF)
+        chip_write_mode = SST_AAI;
+    if (manuf == 0xEF)
+        chip_write_mode = WB_WRITEPAGE;
+
+#ifndef READONLY
+    spi_cmd(EWSR);
+    spi_cs_on();
+    spi_write(WRSR);
+    spi_read();
+    spi_write(0x00);
+    spi_read();
+    spi_cs_off();
+#endif
+    return (uint16_t)(manuf << 8 | product);
+}
+
+
+void spi_flash_sector_erase(uint32_t address)
+{
+    uint8_t status;
+    address &= (~(SPI_FLASH_SECTOR_SIZE - 1));
+
+    wait_busy();
+    flash_write_enable();
+    spi_cs_on();
+    spi_write(SECTOR_ERASE);
+    spi_read();
+    write_address(address);
+    spi_cs_off();
+    wait_busy();
+}
+
+int spi_flash_read(uint32_t address, void *data, int len)
+{
+    uint8_t *buf = data;
+    int i = 0;
+    wait_busy();
+    spi_cs_on();
+    spi_write(BYTE_READ);
+    spi_read();
+    write_address(address);
+    while (len > 0) {
+        spi_write(0xFF);
+        buf[i++] = spi_read();
+        len--;
+    }
+    spi_cs_off();
+    return i;
+}
+
+int spi_flash_write(uint32_t address, const void *data, int len)
+{
+    if (chip_write_mode == SST_AAI)
+        return spi_flash_write_aai(address, data, len);
+    if (chip_write_mode == WB_WRITEPAGE)
+        return spi_flash_write_page(address, data, len);
+    return -1;
+} 
+

src/spi_flash.h

@@ -0,0 +1,9 @@
+#ifndef SPI_FLASH_DRI_H
+#define SPI_FLASH_DRI_H
+#include <stdint.h>
+uint16_t spi_flash_probe(void);
+
+void spi_flash_sector_erase(uint32_t address);
+int spi_flash_read(uint32_t address, void *data, int len);
+int spi_flash_write(uint32_t address, const void *data, int len);
+#endif

src/usecfs.c

@@ -87,7 +87,7 @@ static void cache_commit(void)
             }
         }
 #endif
-    block_write(blockdev, cache, cached_block, 0, BLOCK_SIZE);
+    block_write(blockdev, cache, cached_block);
     cached_block = NO_BLOCK;
 }
 
@@ -97,7 +97,7 @@ static void cache_load(uint32_t blk)
         return;
     if (cached_block != NO_BLOCK)
         cache_commit();
-    if (block_read(blockdev, cache, blk, 0, BLOCK_SIZE) == BLOCK_SIZE) {
+    if (block_read(blockdev, cache, blk) == BLOCK_SIZE) {
         cached_block = blk;
 #ifdef CRYPTO
         if (!is_block_empty()) {

src/usecfs_dev.h

@@ -6,8 +6,8 @@
 #endif
 
 void *block_open(void *args);
-int block_read(void *dev, void *_buf, uint32_t lba, int offset, int count);
+int block_read(void *dev, void *_buf, uint32_t lba);
-int block_write(void *dev, const void *_buf, uint32_t lba, int offset, int count);
+int block_write(void *dev, const void *_buf, uint32_t lba);
 void block_close(void *dev);
 
 #endif

src/usecfs_dev_spi.c

@@ -0,0 +1,36 @@
+#include <stdint.h>
+#include "usecfs_dev.h"
+#include "spi_flash.h"
+
+static uint32_t part_base = 0xFFFFFFFF;
+static uint32_t part_size = 0;
+
+void *block_open(void *args_ptr)
+{
+    uint32_t *args = (uint32_t *)args_ptr;
+    part_base = args[0];
+    part_size = args[1];
+    return &part_base;
+}
+
+int block_read(void *dev, void *_buf, uint32_t lba)
+{
+    if (part_size == 0)
+        return -1;
+    return spi_flash_read(part_base + (lba * BLOCK_SIZE), _buf, BLOCK_SIZE);
+}
+
+int block_write(void *dev, const void *_buf, uint32_t lba)
+{
+    if (part_size == 0)
+        return -1;
+    spi_flash_sector_erase(part_base + lba * BLOCK_SIZE);
+    return spi_flash_write(part_base + lba * BLOCK_SIZE, _buf, BLOCK_SIZE);
+}
+
+void block_close(void *dev)
+{
+    (void)dev;
+    part_base = 0xFFFFFFFF;
+    part_size = 0;
+}

src/usecfs_dev_test.c

@@ -21,19 +21,20 @@ void *block_open(void *args)
     return &fd;
 }
 
-int block_read(void *dev, void *_buf, uint32_t lba, int offset, int count)
+int block_read(void *dev, void *_buf, uint32_t lba)
 {
     (void)dev;
-    lseek(fd, lba * BLOCK_SIZE + offset, SEEK_SET);
+    lseek(fd, lba * BLOCK_SIZE,  SEEK_SET);
-    read(fd, _buf, count);
+    return read(fd, _buf, BLOCK_SIZE);
 }
 
-int block_write(void *dev, const void *_buf, uint32_t lba, int offset, int count)
+int block_write(void *dev, const void *_buf, uint32_t lba)
 {
     (void)dev;
-    lseek(fd, lba * BLOCK_SIZE + offset, SEEK_SET);
+    lseek(fd, lba * BLOCK_SIZE, SEEK_SET);
-    write(fd, _buf, count);
+    return write(fd, _buf, BLOCK_SIZE);
 }
+
 void block_close(void *dev)
 {
     (void)dev;

test/Makefile

@@ -6,4 +6,4 @@ test: main.o ../src/usecfs.o ../src/usecfs_dev_test.o
 	gcc -o $@ $^ -lwolfssl
 
 clean:
-	rm main.o ../src/usecfs.o ../src/usecfs_dev_test.o test
+	@rm -f main.o ../src/*.o