Merge pull request #3481 from cesanta/spi

unify SPI helper APIs

src/drivers/cyw.c

@@ -1178,7 +1178,7 @@ static bool cyw_spi_write(unsigned int f, uint32_t addr, void *data,
                           uint16_t len) {
   struct mg_tcpip_driver_cyw_data *d =
       (struct mg_tcpip_driver_cyw_data *) s_ifp->driver_data;
-  struct mg_tcpip_spi_ *s = (struct mg_tcpip_spi_ *) d->bus;
+  struct mg_tcpip_spi *s = (struct mg_tcpip_spi *) d->bus;
   uint32_t hdr = CYW_SPID_WR | CYW_SPID_INC | CYW_SPID_FUNC(f) |
                  CYW_SPID_ADDR(addr) | CYW_SPID_LEN(len);  // gSPI header
   // TODO(scaprile): check spin in between and timeout values, return false
@@ -1208,7 +1208,7 @@ static void cyw_spi_read(unsigned int f, uint32_t addr, void *data,
                          uint16_t len) {
   struct mg_tcpip_driver_cyw_data *d =
       (struct mg_tcpip_driver_cyw_data *) s_ifp->driver_data;
-  struct mg_tcpip_spi_ *s = (struct mg_tcpip_spi_ *) d->bus;
+  struct mg_tcpip_spi *s = (struct mg_tcpip_spi *) d->bus;
   uint32_t padding =
       f == CYW_SPID_FUNC_CHIP
           ? 4

src/drivers/cyw.h

@@ -4,14 +4,6 @@
     ((defined(MG_ENABLE_DRIVER_CYW) && MG_ENABLE_DRIVER_CYW) || \
      (defined(MG_ENABLE_DRIVER_CYW_SDIO) && MG_ENABLE_DRIVER_CYW_SDIO))
 
-struct mg_tcpip_spi_ {
-  void *spi;              // Opaque SPI bus descriptor
-  void (*begin)(void *);  // SPI begin: slave select low
-  void (*end)(void *);    // SPI end: slave select high
-  void (*txn)(void *, uint8_t *, uint8_t *,
-              size_t len);  // SPI transaction: write-read len bytes
-};
-
 struct mg_tcpip_driver_cyw_firmware {
   const uint8_t *code_addr;
   size_t code_len;

src/drivers/st67w6.c

@@ -439,7 +439,7 @@ static size_t st67w6_spi_poll(uint8_t *write, uint8_t *read) {
   struct mg_tcpip_driver_st67w6_data *d =
       (struct mg_tcpip_driver_st67w6_data *) s_ifp->driver_data;
   struct spi_hdr *th, *rh = (struct spi_hdr *) read;
-  struct mg_tcpip_spi_ *s = (struct mg_tcpip_spi_ *) d->spi;
+  struct mg_tcpip_spi *s = (struct mg_tcpip_spi *) d->spi;
   size_t padded;
   unsigned int times;
 

src/drivers/st67w6.h

@@ -3,14 +3,6 @@
 #if MG_ENABLE_TCPIP && defined(MG_ENABLE_DRIVER_ST67W6) && \
     MG_ENABLE_DRIVER_ST67W6
 
-struct mg_tcpip_spi_ {
-  void *spi;              // Opaque SPI bus descriptor
-  void (*begin)(void *);  // SPI begin: slave select low
-  void (*end)(void *);    // SPI end: slave select high
-  void (*txn)(void *, uint8_t *, uint8_t *,
-              size_t len);  // SPI transaction: write-read len bytes
-};
-
 struct mg_tcpip_driver_st67w6_data {
   struct mg_wifi_data wifi;
   void *spi;

src/drivers/w5100.c

@@ -4,16 +4,12 @@
 
 static void w5100_txn(struct mg_tcpip_spi *s, uint16_t addr, bool wr, void *buf,
                       size_t len) {
-  size_t i;
-  uint8_t *p = (uint8_t *) buf;
   uint8_t control = wr ? 0xF0 : 0x0F;
   uint8_t cmd[] = {control, (uint8_t) (addr >> 8), (uint8_t) (addr & 255)};
   s->begin(s->spi);
-  for (i = 0; i < sizeof(cmd); i++) s->txn(s->spi, cmd[i]);
-  for (i = 0; i < len; i++) {
-    uint8_t r = s->txn(s->spi, p[i]);
-    if (!wr) p[i] = r;
-  }
+  s->txn(s->spi, cmd, NULL, sizeof(cmd));
+  if (wr) s->txn(s->spi, (uint8_t *) buf, NULL, len);
+  if (!wr) s->txn(s->spi, NULL, (uint8_t *) buf, len);
   s->end(s->spi);
 }
 

src/drivers/w5500.c

@@ -6,16 +6,12 @@ enum { W5500_CR = 0, W5500_S0 = 1, W5500_TX0 = 2, W5500_RX0 = 3 };
 
 static void w5500_txn(struct mg_tcpip_spi *s, uint8_t block, uint16_t addr,
                       bool wr, void *buf, size_t len) {
-  size_t i;
-  uint8_t *p = (uint8_t *) buf;
   uint8_t cmd[] = {(uint8_t) (addr >> 8), (uint8_t) (addr & 255),
                    (uint8_t) ((block << 3) | (wr ? 4 : 0))};
   s->begin(s->spi);
-  for (i = 0; i < sizeof(cmd); i++) s->txn(s->spi, cmd[i]);
-  for (i = 0; i < len; i++) {
-    uint8_t r = s->txn(s->spi, p[i]);
-    if (!wr) p[i] = r;
-  }
+  s->txn(s->spi, cmd, NULL, sizeof(cmd));
+  if (wr) s->txn(s->spi, (uint8_t *) buf, NULL, len);
+  if (!wr) s->txn(s->spi, NULL, (uint8_t *) buf, len);
   s->end(s->spi);
 }
 

src/net_builtin.h

@@ -122,10 +122,11 @@ extern struct mg_tcpip_driver mg_tcpip_driver_atcmd;
 
 // Drivers that require SPI, can use this SPI abstraction
 struct mg_tcpip_spi {
-  void *spi;                        // Opaque SPI bus descriptor
-  void (*begin)(void *);            // SPI begin: slave select low
-  void (*end)(void *);              // SPI end: slave select high
-  uint8_t (*txn)(void *, uint8_t);  // SPI transaction: write 1 byte, read reply
+  void *spi;              // Opaque SPI bus descriptor
+  void (*begin)(void *);  // SPI begin: slave select active
+  void (*end)(void *);    // SPI end: slave select inactive
+  void (*txn)(void *, uint8_t *write, uint8_t *read,
+              size_t len);  // SPI transaction: write-read len bytes
 };
 
 // Alignment and memory section requirements