esp32/network_lan: Support configuration of ETH ref_clk pin.

Both the direction and the Pin used for ref_clk can now be configured.  It
Requires at least idf v4.4.  The new keyword arguments to the constructor
are:

- ref_clk_mode=mode: with mode being Pin.IN or Pin.OUT.  If it is not set,
  then the default configuration is used, which may be configured by
  kconfig settings.

- ref_clk=pin_obj: which defines the Pin used for ref_clk.  This is either
  Pin(0), Pin(16) or Pin(17).  No check is done for the pin number.  If it
  is the wrong one, it simply will not work.  Besides that, no harm.

1 files changed, 18 insertions, 1 deletions

diff --git a/ports/esp32/network_lan.c b/ports/esp32/network_lan.c
index 3cd1efc04..471e31d62 100644
--- a/ports/esp32/network_lan.c
+++ b/ports/esp32/network_lan.c
@@ -97,7 +97,8 @@ STATIC mp_obj_t get_lan(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_ar
         return MP_OBJ_FROM_PTR(&lan_obj);
     }
 
-    enum { ARG_id, ARG_mdc, ARG_mdio, ARG_power, ARG_phy_addr, ARG_phy_type };
+    enum { ARG_id, ARG_mdc, ARG_mdio, ARG_power, ARG_phy_addr, ARG_phy_type,
+           ARG_ref_clk_mode, ARG_ref_clk };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_id,           MP_ARG_OBJ, {.u_obj = mp_const_none} },
         { MP_QSTR_mdc,          MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_OBJ },
@@ -105,6 +106,11 @@ STATIC mp_obj_t get_lan(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_ar
         { MP_QSTR_power,        MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
         { MP_QSTR_phy_addr,     MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
         { MP_QSTR_phy_type,     MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
+        // Dynamic ref_clk configuration available at v4.4
+        #if ESP_IDF_VERSION_MINOR >= 4
+        { MP_QSTR_ref_clk_mode, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
+        { MP_QSTR_ref_clk,      MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
+        #endif
     };
 
     mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
@@ -139,6 +145,17 @@ STATIC mp_obj_t get_lan(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_ar
     eth_mac_config_t mac_config = ETH_MAC_DEFAULT_CONFIG();
     mac_config.smi_mdc_gpio_num = self->mdc_pin;
     mac_config.smi_mdio_gpio_num = self->mdio_pin;
+    // Dynamic ref_clk configuration available at v4.4
+    #if ESP_IDF_VERSION_MINOR >= 4
+    if (args[ARG_ref_clk_mode].u_int != -1) {
+        // Map the GPIO_MODE constants to EMAC_CLK constants.
+        mac_config.clock_config.rmii.clock_mode =
+            args[ARG_ref_clk_mode].u_int == GPIO_MODE_INPUT ? EMAC_CLK_EXT_IN : EMAC_CLK_OUT;
+    }
+    if (args[ARG_ref_clk].u_obj != mp_const_none) {
+        mac_config.clock_config.rmii.clock_gpio = machine_pin_get_id(args[ARG_ref_clk].u_obj);
+    }
+    #endif
     esp_eth_mac_t *mac = esp_eth_mac_new_esp32(&mac_config);
 
     eth_phy_config_t phy_config = ETH_PHY_DEFAULT_CONFIG();