esp32/machine_hw_spi: Use default pins when making SPI if none given.

The default pins can be optionally configured by a board.

Fixes issue #6974.

Signed-off-by: Damien George <damien@micropython.org>

2 files changed, 33 insertions, 3 deletions

diff --git a/docs/esp32/quickref.rst b/docs/esp32/quickref.rst
index 79e61a10b..30c9b3b95 100644
--- a/docs/esp32/quickref.rst
+++ b/docs/esp32/quickref.rst
@@ -302,6 +302,7 @@ has the same methods as software SPI above::
 
     from machine import Pin, SPI
 
+    hspi = SPI(1, 10000000)
     hspi = SPI(1, 10000000, sck=Pin(14), mosi=Pin(13), miso=Pin(12))
     vspi = SPI(2, baudrate=80000000, polarity=0, phase=0, bits=8, firstbit=0, sck=Pin(18), mosi=Pin(23), miso=Pin(19))
 
diff --git a/ports/esp32/machine_hw_spi.c b/ports/esp32/machine_hw_spi.c
index 3790b4e0c..d59f2c750 100644
--- a/ports/esp32/machine_hw_spi.c
+++ b/ports/esp32/machine_hw_spi.c
@@ -36,9 +36,29 @@
 
 #include "driver/spi_master.h"
 
+// Default pins for SPI(1), can be overridden by a board
+#ifndef MICROPY_HW_SPI1_SCK
+#define MICROPY_HW_SPI1_SCK (14)
+#define MICROPY_HW_SPI1_MOSI (13)
+#define MICROPY_HW_SPI1_MISO (12)
+#endif
+
+// Default pins for SPI(2), can be overridden by a board
+#ifndef MICROPY_HW_SPI2_SCK
+#define MICROPY_HW_SPI2_SCK (18)
+#define MICROPY_HW_SPI2_MOSI (23)
+#define MICROPY_HW_SPI2_MISO (19)
+#endif
+
 #define MP_HW_SPI_MAX_XFER_BYTES (4092)
 #define MP_HW_SPI_MAX_XFER_BITS (MP_HW_SPI_MAX_XFER_BYTES * 8) // Has to be an even multiple of 8
 
+typedef struct _machine_hw_spi_default_pins_t {
+    int8_t sck;
+    int8_t mosi;
+    int8_t miso;
+} machine_hw_spi_default_pins_t;
+
 typedef struct _machine_hw_spi_obj_t {
     mp_obj_base_t base;
     spi_host_device_t host;
@@ -58,6 +78,12 @@ typedef struct _machine_hw_spi_obj_t {
     } state;
 } machine_hw_spi_obj_t;
 
+// Default pin mappings for the hardware SPI instances
+STATIC const machine_hw_spi_default_pins_t machine_hw_spi_default_pins[2] = {
+    { .sck = MICROPY_HW_SPI1_SCK, .mosi = MICROPY_HW_SPI1_MOSI, .miso = MICROPY_HW_SPI1_MISO },
+    { .sck = MICROPY_HW_SPI2_SCK, .mosi = MICROPY_HW_SPI2_MOSI, .miso = MICROPY_HW_SPI2_MISO },
+};
+
 // Static objects mapping to HSPI and VSPI hardware peripherals
 STATIC machine_hw_spi_obj_t machine_hw_spi_obj[2];
 
@@ -369,10 +395,13 @@ mp_obj_t machine_hw_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_
     mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
 
     machine_hw_spi_obj_t *self;
+    const machine_hw_spi_default_pins_t *default_pins;
     if (args[ARG_id].u_int == HSPI_HOST) {
         self = &machine_hw_spi_obj[0];
+        default_pins = &machine_hw_spi_default_pins[0];
     } else {
         self = &machine_hw_spi_obj[1];
+        default_pins = &machine_hw_spi_default_pins[1];
     }
     self->base.type = &machine_hw_spi_type;
 
@@ -384,9 +413,9 @@ mp_obj_t machine_hw_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_
         args[ARG_phase].u_int,
         args[ARG_bits].u_int,
         args[ARG_firstbit].u_int,
-        args[ARG_sck].u_obj == MP_OBJ_NULL ? -1 : machine_pin_get_id(args[ARG_sck].u_obj),
-        args[ARG_mosi].u_obj == MP_OBJ_NULL ? -1 : machine_pin_get_id(args[ARG_mosi].u_obj),
-        args[ARG_miso].u_obj == MP_OBJ_NULL ? -1 : machine_pin_get_id(args[ARG_miso].u_obj));
+        args[ARG_sck].u_obj == MP_OBJ_NULL ? default_pins->sck : machine_pin_get_id(args[ARG_sck].u_obj),
+        args[ARG_mosi].u_obj == MP_OBJ_NULL ? default_pins->mosi : machine_pin_get_id(args[ARG_mosi].u_obj),
+        args[ARG_miso].u_obj == MP_OBJ_NULL ? default_pins->miso : machine_pin_get_id(args[ARG_miso].u_obj));
 
     return MP_OBJ_FROM_PTR(self);
 }