ports: Support legacy soft I2C/SPI construction via id=-1 arg.

With a warning that this way of constructing software I2C/SPI is
deprecated.  The check and warning will be removed in a future release.

This should help existing code to migrate to the new SoftI2C/SoftSPI types.

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

extmod/machine_i2c.h

@@ -29,6 +29,19 @@
 #include "py/obj.h"
 #include "py/mphal.h"
 
+// Temporary support for legacy construction of SoftI2C via I2C type.
+#define MP_MACHINE_I2C_CHECK_FOR_LEGACY_SOFTI2C_CONSTRUCTION(n_args, n_kw, all_args) \
+    do { \
+        if (n_args == 0 || all_args[0] == MP_OBJ_NEW_SMALL_INT(-1)) { \
+            mp_print_str(MICROPY_ERROR_PRINTER, "Warning: I2C(-1, ...) is deprecated, use SoftI2C(...) instead\n"); \
+            if (n_args != 0) { \
+                --n_args; \
+                ++all_args; \
+            } \
+            return mp_machine_soft_i2c_type.make_new(&mp_machine_soft_i2c_type, n_args, n_kw, all_args); \
+        } \
+    } while (0)
+
 #define MP_MACHINE_I2C_FLAG_READ (0x01) // if not set then it's a write
 #define MP_MACHINE_I2C_FLAG_STOP (0x02)
 

extmod/machine_spi.h

@@ -30,6 +30,19 @@
 #include "py/mphal.h"
 #include "drivers/bus/spi.h"
 
+// Temporary support for legacy construction of SoftSPI via SPI type.
+#define MP_MACHINE_SPI_CHECK_FOR_LEGACY_SOFTSPI_CONSTRUCTION(n_args, n_kw, all_args) \
+    do { \
+        if (n_args == 0 || all_args[0] == MP_OBJ_NEW_SMALL_INT(-1)) { \
+            mp_print_str(MICROPY_ERROR_PRINTER, "Warning: SPI(-1, ...) is deprecated, use SoftSPI(...) instead\n"); \
+            if (n_args != 0) { \
+                --n_args; \
+                ++all_args; \
+            } \
+            return mp_machine_soft_spi_type.make_new(&mp_machine_soft_spi_type, n_args, n_kw, all_args); \
+        } \
+    } while (0)
+
 // SPI protocol
 typedef struct _mp_machine_spi_p_t {
     void (*init)(mp_obj_base_t *obj, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args);

ports/esp32/machine_hw_spi.c

@@ -351,6 +351,8 @@ STATIC void machine_hw_spi_init(mp_obj_base_t *self_in, size_t n_args, const mp_
 }
 
 mp_obj_t machine_hw_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    MP_MACHINE_SPI_CHECK_FOR_LEGACY_SOFTSPI_CONSTRUCTION(n_args, n_kw, all_args);
+
     enum { ARG_id, ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits, ARG_firstbit, ARG_sck, ARG_mosi, ARG_miso };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_id,       MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = -1} },

ports/esp32/machine_i2c.c

@@ -115,6 +115,8 @@ STATIC void machine_hw_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_p
 }
 
 mp_obj_t machine_hw_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    MP_MACHINE_I2C_CHECK_FOR_LEGACY_SOFTI2C_CONSTRUCTION(n_args, n_kw, all_args);
+
     // Parse args
     enum { ARG_id, ARG_scl, ARG_sda, ARG_freq, ARG_timeout };
     static const mp_arg_t allowed_args[] = {

ports/esp8266/machine_hspi.c

@@ -151,6 +151,8 @@ STATIC void machine_hspi_init(mp_obj_base_t *self_in, size_t n_args, const mp_ob
 }
 
 mp_obj_t machine_hspi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    MP_MACHINE_SPI_CHECK_FOR_LEGACY_SOFTSPI_CONSTRUCTION(n_args, n_kw, args);
+
     // args[0] holds the id of the peripheral
     if (args[0] != MP_OBJ_NEW_SMALL_INT(1)) {
         // FlashROM is on SPI0, so far we don't support its usage

ports/nrf/modules/machine/i2c.c

@@ -94,6 +94,8 @@ STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp
 /* MicroPython bindings for machine API                                       */
 
 mp_obj_t machine_hard_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    MP_MACHINE_I2C_CHECK_FOR_LEGACY_SOFTI2C_CONSTRUCTION(n_args, n_kw, all_args);
+
     enum { ARG_id, ARG_scl, ARG_sda };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_id,       MP_ARG_REQUIRED | MP_ARG_OBJ },

ports/stm32/machine_i2c.c

@@ -193,6 +193,8 @@ STATIC void machine_hard_i2c_init(machine_hard_i2c_obj_t *self, uint32_t freq, u
 #endif
 
 mp_obj_t machine_hard_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    MP_MACHINE_I2C_CHECK_FOR_LEGACY_SOFTI2C_CONSTRUCTION(n_args, n_kw, all_args);
+
     // parse args
     enum { ARG_id, ARG_scl, ARG_sda, ARG_freq, ARG_timeout, ARG_timingr };
     static const mp_arg_t allowed_args[] = {

ports/stm32/machine_spi.c

@@ -46,6 +46,8 @@ STATIC void machine_hard_spi_print(const mp_print_t *print, mp_obj_t self_in, mp
 }
 
 mp_obj_t machine_hard_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    MP_MACHINE_SPI_CHECK_FOR_LEGACY_SOFTSPI_CONSTRUCTION(n_args, n_kw, all_args);
+
     enum { ARG_id, ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits, ARG_firstbit, ARG_sck, ARG_mosi, ARG_miso };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_id,       MP_ARG_REQUIRED | MP_ARG_OBJ },

ports/zephyr/machine_i2c.c

@@ -51,6 +51,8 @@ STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp
 }
 
 mp_obj_t machine_hard_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    MP_MACHINE_I2C_CHECK_FOR_LEGACY_SOFTI2C_CONSTRUCTION(n_args, n_kw, all_args);
+
     enum { ARG_id, ARG_scl, ARG_sda, ARG_freq, ARG_timeout };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ },