stm32: Add network driver for Wiznet5k using MACRAW mode and lwIP.

The Wiznet5k series of chips support a MACRAW mode which allows the host to
send and receive Ethernet frames directly.  This can be hooked into the
lwIP stack to provide a full "socket" implementation using this Wiznet
Ethernet device.  This patch adds support for this feature.

To enable the feature one must add the following to mpconfigboard.mk, or
mpconfigport.mk:

    MICROPY_PY_WIZNET5K = 5500

and the following to mpconfigboard.h, or mpconfigport.h:

    #define MICROPY_PY_LWIP (1)

After wiring up the module (X5=CS, X4=RST), usage on a pyboard is:

    import time, network
    nic = network.WIZNET5K(pyb.SPI(1), pyb.Pin.board.X5, pyb.Pin.board.X4)
    nic.active(1)
    while not nic.isconnected():
        time.sleep_ms(50) # needed to poll the NIC
    print(nic.ifconfig())

Then use the socket module as usual.

Compared to using the built-in TCP/IP stack on the Wiznet module, some
performance is lost in MACRAW mode: with a lot of memory allocated to lwIP
buffers, lwIP gives Around 750,000 bytes/sec max TCP download, compared
with 1M/sec when using the TCP/IP stack on the Wiznet module.

4 files changed, 424 insertions, 1 deletions

diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
index afb21b048..a072e106b 100644
--- a/ports/stm32/Makefile
+++ b/ports/stm32/Makefile
@@ -328,7 +328,7 @@ ifneq ($(MICROPY_PY_WIZNET5K),0)
 WIZNET5K_DIR=drivers/wiznet5k
 INC += -I$(TOP)/$(WIZNET5K_DIR)
 CFLAGS_MOD += -DMICROPY_PY_WIZNET5K=$(MICROPY_PY_WIZNET5K) -D_WIZCHIP_=$(MICROPY_PY_WIZNET5K)
-SRC_MOD += modnwwiznet5k.c
+SRC_MOD += network_wiznet5k.c modnwwiznet5k.c
 SRC_MOD += $(addprefix $(WIZNET5K_DIR)/,\
 	ethernet/w$(MICROPY_PY_WIZNET5K)/w$(MICROPY_PY_WIZNET5K).c \
 	ethernet/wizchip_conf.c \
diff --git a/ports/stm32/modnetwork.h b/ports/stm32/modnetwork.h
index 3224d785e..f45e00fbc 100644
--- a/ports/stm32/modnetwork.h
+++ b/ports/stm32/modnetwork.h
@@ -44,6 +44,8 @@ typedef struct _mod_network_nic_type_t {
     void (*poll_callback)(void *data, struct netif *netif);
 } mod_network_nic_type_t;
 
+extern const mp_obj_type_t mod_network_nic_type_wiznet5k;
+
 mp_obj_t mod_network_nic_ifconfig(struct netif *netif, size_t n_args, const mp_obj_t *args);
 
 #else
diff --git a/ports/stm32/modnwwiznet5k.c b/ports/stm32/modnwwiznet5k.c
index 017bd42f8..bf4b72ff2 100644
--- a/ports/stm32/modnwwiznet5k.c
+++ b/ports/stm32/modnwwiznet5k.c
@@ -38,6 +38,8 @@
 #include "pin.h"
 #include "spi.h"
 
+#if MICROPY_PY_WIZNET5K && !MICROPY_PY_LWIP
+
 #include "ethernet/wizchip_conf.h"
 #include "ethernet/socket.h"
 #include "internet/dns/dns.h"
@@ -499,3 +501,5 @@ const mod_network_nic_type_t mod_network_nic_type_wiznet5k = {
     .settimeout = wiznet5k_socket_settimeout,
     .ioctl = wiznet5k_socket_ioctl,
 };
+
+#endif // MICROPY_PY_WIZNET5K && !MICROPY_PY_LWIP
diff --git a/ports/stm32/network_wiznet5k.c b/ports/stm32/network_wiznet5k.c
new file mode 100644
index 000000000..9db42b787
--- /dev/null
+++ b/ports/stm32/network_wiznet5k.c
@@ -0,0 +1,417 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014-2018 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include "py/runtime.h"
+#include "py/mphal.h"
+#include "spi.h"
+#include "modnetwork.h"
+
+#if MICROPY_PY_WIZNET5K && MICROPY_PY_LWIP
+
+#include "drivers/wiznet5k/ethernet/socket.h"
+#include "lwip/err.h"
+#include "lwip/dns.h"
+#include "lwip/dhcp.h"
+#include "netif/etharp.h"
+
+/*******************************************************************************/
+// Wiznet5k Ethernet driver in MACRAW mode
+
+typedef struct _wiznet5k_obj_t {
+    mod_network_nic_type_t base;
+    mp_uint_t cris_state;
+    const spi_t *spi;
+    mp_hal_pin_obj_t cs;
+    mp_hal_pin_obj_t rst;
+    uint8_t eth_frame[1514];
+    struct netif netif;
+    struct dhcp dhcp_struct;
+} wiznet5k_obj_t;
+
+// Global object holding the Wiznet5k state
+STATIC wiznet5k_obj_t wiznet5k_obj;
+
+STATIC void wiznet5k_lwip_init(wiznet5k_obj_t *self);
+STATIC void wiznet5k_lwip_poll(void *self_in, struct netif *netif);
+
+STATIC void wiz_cris_enter(void) {
+    wiznet5k_obj.cris_state = MICROPY_BEGIN_ATOMIC_SECTION();
+}
+
+STATIC void wiz_cris_exit(void) {
+    MICROPY_END_ATOMIC_SECTION(wiznet5k_obj.cris_state);
+}
+
+STATIC void wiz_cs_select(void) {
+    mp_hal_pin_low(wiznet5k_obj.cs);
+}
+
+STATIC void wiz_cs_deselect(void) {
+    mp_hal_pin_high(wiznet5k_obj.cs);
+}
+
+STATIC void wiz_spi_read(uint8_t *buf, uint32_t len) {
+    HAL_StatusTypeDef status = HAL_SPI_Receive(wiznet5k_obj.spi->spi, buf, len, 5000);
+    (void)status;
+}
+
+STATIC void wiz_spi_write(const uint8_t *buf, uint32_t len) {
+    HAL_StatusTypeDef status = HAL_SPI_Transmit(wiznet5k_obj.spi->spi, (uint8_t*)buf, len, 5000);
+    (void)status;
+}
+
+STATIC void wiznet5k_init(void) {
+    // SPI configuration
+    SPI_InitTypeDef *init = &wiznet5k_obj.spi->spi->Init;
+    init->Mode = SPI_MODE_MASTER;
+    init->Direction = SPI_DIRECTION_2LINES;
+    init->DataSize = SPI_DATASIZE_8BIT;
+    init->CLKPolarity = SPI_POLARITY_LOW; // clock is low when idle
+    init->CLKPhase = SPI_PHASE_1EDGE; // data latched on first edge, which is rising edge for low-idle
+    init->NSS = SPI_NSS_SOFT;
+    init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2; // clock freq = f_PCLK / this_prescale_value; Wiz820i can do up to 80MHz
+    init->FirstBit = SPI_FIRSTBIT_MSB;
+    init->TIMode = SPI_TIMODE_DISABLED;
+    init->CRCCalculation = SPI_CRCCALCULATION_DISABLED;
+    init->CRCPolynomial = 7; // unused
+    spi_init(wiznet5k_obj.spi, false);
+
+    mp_hal_pin_output(wiznet5k_obj.cs);
+    mp_hal_pin_output(wiznet5k_obj.rst);
+
+    // Reset the chip
+    mp_hal_pin_low(wiznet5k_obj.rst);
+    mp_hal_delay_ms(1); // datasheet says 2us
+    mp_hal_pin_high(wiznet5k_obj.rst);
+    mp_hal_delay_ms(150); // datasheet says 150ms
+
+    // Set physical interface callbacks
+    reg_wizchip_cris_cbfunc(wiz_cris_enter, wiz_cris_exit);
+    reg_wizchip_cs_cbfunc(wiz_cs_select, wiz_cs_deselect);
+    reg_wizchip_spi_cbfunc(wiz_spi_read, wiz_spi_write);
+
+    // Configure 16k buffers for fast MACRAW
+    uint8_t sn_size[16] = {16, 0, 0, 0, 0, 0, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0};
+    ctlwizchip(CW_INIT_WIZCHIP, sn_size);
+
+    // Seems we need a small delay after init
+    mp_hal_delay_ms(250);
+
+    // Hook the Wiznet into lwIP
+    wiznet5k_lwip_init(&wiznet5k_obj);
+}
+
+STATIC void wiznet5k_deinit(void) {
+    for (struct netif *netif = netif_list; netif != NULL; netif = netif->next) {
+        if (netif == &wiznet5k_obj.netif) {
+            netif_remove(netif);
+            netif->flags = 0;
+            break;
+        }
+    }
+}
+
+STATIC void wiznet5k_get_mac_address(wiznet5k_obj_t *self, uint8_t mac[6]) {
+    (void)self;
+    getSHAR(mac);
+}
+
+STATIC void wiznet5k_send_ethernet(wiznet5k_obj_t *self, size_t len, const uint8_t *buf) {
+    uint8_t ip[4] = {1, 1, 1, 1}; // dummy
+    int ret = WIZCHIP_EXPORT(sendto)(0, (byte*)buf, len, ip, 11); // dummy port
+    if (ret != len) {
+        printf("wiznet5k_send_ethernet: fatal error %d\n", ret);
+        netif_set_link_down(&self->netif);
+        netif_set_down(&self->netif);
+    }
+}
+
+// Stores the frame in self->eth_frame and returns number of bytes in the frame, 0 for no frame
+STATIC uint16_t wiznet5k_recv_ethernet(wiznet5k_obj_t *self) {
+    uint16_t len = getSn_RX_RSR(0);
+    if (len == 0) {
+        return 0;
+    }
+
+    byte ip[4];
+    uint16_t port;
+    int ret = WIZCHIP_EXPORT(recvfrom)(0, self->eth_frame, 1514, ip, &port);
+    if (ret <= 0) {
+        printf("wiznet5k_lwip_poll: fatal error len=%u ret=%d\n", len, ret);
+        netif_set_link_down(&self->netif);
+        netif_set_down(&self->netif);
+        return 0;
+    }
+
+    return ret;
+}
+
+/*******************************************************************************/
+// Wiznet5k lwIP interface
+
+STATIC err_t wiznet5k_netif_output(struct netif *netif, struct pbuf *p) {
+    wiznet5k_obj_t *self = netif->state;
+    pbuf_copy_partial(p, self->eth_frame, p->tot_len, 0);
+    wiznet5k_send_ethernet(self, p->tot_len, self->eth_frame);
+    return ERR_OK;
+}
+
+STATIC err_t wiznet5k_netif_init(struct netif *netif) {
+    netif->linkoutput = wiznet5k_netif_output;
+    netif->output = etharp_output;
+    netif->mtu = 1500;
+    netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_ETHERNET | NETIF_FLAG_IGMP;
+    wiznet5k_get_mac_address(netif->state, netif->hwaddr);
+    netif->hwaddr_len = sizeof(netif->hwaddr);
+    int ret = WIZCHIP_EXPORT(socket)(0, Sn_MR_MACRAW, 0, 0);
+    if (ret != 0) {
+        printf("WIZNET fatal error in netifinit: %d\n", ret);
+        return ERR_IF;
+    }
+
+    // Enable MAC filtering so we only get frames destined for us, to reduce load on lwIP
+    setSn_MR(0, getSn_MR(0) | Sn_MR_MFEN);
+
+    return ERR_OK;
+}
+
+STATIC void wiznet5k_lwip_init(wiznet5k_obj_t *self) {
+    ip_addr_t ipconfig[4];
+    ipconfig[0].addr = 0;
+    ipconfig[1].addr = 0;
+    ipconfig[2].addr = 0;
+    ipconfig[3].addr = 0;
+    netif_add(&self->netif, &ipconfig[0], &ipconfig[1], &ipconfig[2], self, wiznet5k_netif_init, ethernet_input);
+    self->netif.name[0] = 'e';
+    self->netif.name[1] = '0';
+    netif_set_default(&self->netif);
+    dns_setserver(0, &ipconfig[3]);
+    dhcp_set_struct(&self->netif, &self->dhcp_struct);
+    // Setting NETIF_FLAG_UP then clearing it is a workaround for dhcp_start and the
+    // LWIP_DHCP_CHECK_LINK_UP option, so that the DHCP client schedules itself to
+    // automatically start when the interface later goes up.
+    self->netif.flags |= NETIF_FLAG_UP;
+    dhcp_start(&self->netif);
+    self->netif.flags &= ~NETIF_FLAG_UP;
+}
+
+STATIC void wiznet5k_lwip_poll(void *self_in, struct netif *netif) {
+    wiznet5k_obj_t *self = self_in;
+    uint16_t len;
+    while ((len = wiznet5k_recv_ethernet(self)) > 0) {
+        struct pbuf *p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
+        if (p != NULL) {
+            pbuf_take(p, self->eth_frame, len);
+            if (self->netif.input(p, &self->netif) != ERR_OK) {
+                pbuf_free(p);
+            }
+        }
+    }
+}
+
+/*******************************************************************************/
+// MicroPython bindings
+
+// WIZNET5K([spi, pin_cs, pin_rst])
+STATIC mp_obj_t wiznet5k_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    // check arguments
+    mp_arg_check_num(n_args, n_kw, 3, 3, false);
+
+    const spi_t *spi = spi_from_mp_obj(args[0]);
+    mp_hal_pin_obj_t cs = pin_find(args[1]);
+    mp_hal_pin_obj_t rst = pin_find(args[2]);
+
+    // Access the existing object, if it has been constructed with the same hardware interface
+    if (wiznet5k_obj.base.base.type == &mod_network_nic_type_wiznet5k) {
+        if (!(wiznet5k_obj.spi == spi && wiznet5k_obj.cs == cs && wiznet5k_obj.rst == rst
+            && wiznet5k_obj.netif.flags != 0)) {
+            wiznet5k_deinit();
+        }
+    }
+
+    // Init the wiznet5k object
+    wiznet5k_obj.base.base.type = &mod_network_nic_type_wiznet5k;
+    wiznet5k_obj.base.poll_callback = wiznet5k_lwip_poll;
+    wiznet5k_obj.cris_state = 0;
+    wiznet5k_obj.spi = spi;
+    wiznet5k_obj.cs = cs;
+    wiznet5k_obj.rst = rst;
+
+    // Return wiznet5k object
+    return MP_OBJ_FROM_PTR(&wiznet5k_obj);
+}
+
+STATIC mp_obj_t wiznet5k_regs(mp_obj_t self_in) {
+    (void)self_in;
+    printf("Wiz CREG:");
+    for (int i = 0; i < 0x50; ++i) {
+        if (i % 16 == 0) {
+            printf("\n  %04x:", i);
+        }
+        #if MICROPY_PY_WIZNET5K == 5200
+        uint32_t reg = i;
+        #else
+        uint32_t reg = _W5500_IO_BASE_ | i << 8;
+        #endif
+        printf(" %02x", WIZCHIP_READ(reg));
+    }
+    for (int sn = 0; sn < 4; ++sn) {
+        printf("\nWiz SREG[%d]:", sn);
+        for (int i = 0; i < 0x30; ++i) {
+            if (i % 16 == 0) {
+                printf("\n  %04x:", i);
+            }
+            #if MICROPY_PY_WIZNET5K == 5200
+            uint32_t reg = WIZCHIP_SREG_ADDR(sn, i);
+            #else
+            uint32_t reg = _W5500_IO_BASE_ | i << 8 | WIZCHIP_SREG_BLOCK(sn) << 3;
+            #endif
+            printf(" %02x", WIZCHIP_READ(reg));
+        }
+    }
+    printf("\n");
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(wiznet5k_regs_obj, wiznet5k_regs);
+
+STATIC mp_obj_t wiznet5k_isconnected(mp_obj_t self_in) {
+    wiznet5k_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    return mp_obj_new_bool(
+        wizphy_getphylink() == PHY_LINK_ON
+        && (self->netif.flags & NETIF_FLAG_UP)
+        && self->netif.ip_addr.addr != 0
+    );
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(wiznet5k_isconnected_obj, wiznet5k_isconnected);
+
+STATIC mp_obj_t wiznet5k_active(size_t n_args, const mp_obj_t *args) {
+    wiznet5k_obj_t *self = MP_OBJ_TO_PTR(args[0]);
+    if (n_args == 1) {
+        return mp_obj_new_bool(self->netif.flags & NETIF_FLAG_UP);
+    } else {
+        if (mp_obj_is_true(args[1])) {
+            if (!(self->netif.flags & NETIF_FLAG_UP)) {
+                wiznet5k_init();
+                netif_set_link_up(&self->netif);
+                netif_set_up(&self->netif);
+            }
+        } else {
+            if (self->netif.flags & NETIF_FLAG_UP) {
+                netif_set_down(&self->netif);
+                netif_set_link_down(&self->netif);
+                wiznet5k_deinit();
+            }
+        }
+        return mp_const_none;
+    }
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(wiznet5k_active_obj, 1, 2, wiznet5k_active);
+
+STATIC mp_obj_t wiznet5k_ifconfig(size_t n_args, const mp_obj_t *args) {
+    wiznet5k_obj_t *self = MP_OBJ_TO_PTR(args[0]);
+    return mod_network_nic_ifconfig(&self->netif, n_args - 1, args + 1);
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(wiznet5k_ifconfig_obj, 1, 2, wiznet5k_ifconfig);
+
+STATIC mp_obj_t wiznet5k_status(size_t n_args, const mp_obj_t *args) {
+    wiznet5k_obj_t *self = MP_OBJ_TO_PTR(args[0]);
+    (void)self;
+
+    if (n_args == 1) {
+        // No arguments: return link status
+        if (self->netif.flags && wizphy_getphylink() == PHY_LINK_ON) {
+            if ((self->netif.flags & NETIF_FLAG_UP) && self->netif.ip_addr.addr != 0) {
+                return MP_OBJ_NEW_SMALL_INT(2);
+            } else {
+                return MP_OBJ_NEW_SMALL_INT(1);
+            }
+        } else {
+            return MP_OBJ_NEW_SMALL_INT(0);
+        }
+    }
+
+    mp_raise_ValueError("unknown config param");
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(wiznet5k_status_obj, 1, 2, wiznet5k_status);
+
+STATIC mp_obj_t wiznet5k_config(size_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
+    wiznet5k_obj_t *self = MP_OBJ_TO_PTR(args[0]);
+
+    if (kwargs->used == 0) {
+        // Get config value
+        if (n_args != 2) {
+            mp_raise_TypeError("must query one param");
+        }
+
+        switch (mp_obj_str_get_qstr(args[1])) {
+            case MP_QSTR_mac: {
+                uint8_t buf[6];
+                wiznet5k_get_mac_address(self, buf);
+                return mp_obj_new_bytes(buf, 6);
+            }
+            default:
+                mp_raise_ValueError("unknown config param");
+        }
+    } else {
+        // Set config value(s)
+        if (n_args != 1) {
+            mp_raise_TypeError("can't specify pos and kw args");
+        }
+        mp_raise_ValueError("unknown config param");
+    }
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(wiznet5k_config_obj, 1, wiznet5k_config);
+
+STATIC mp_obj_t send_ethernet_wrapper(mp_obj_t self_in, mp_obj_t buf_in) {
+    wiznet5k_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_buffer_info_t buf;
+    mp_get_buffer_raise(buf_in, &buf, MP_BUFFER_READ);
+    wiznet5k_send_ethernet(self, buf.len, buf.buf);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(send_ethernet_obj, send_ethernet_wrapper);
+
+STATIC const mp_rom_map_elem_t wiznet5k_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_regs), MP_ROM_PTR(&wiznet5k_regs_obj) },
+    { MP_ROM_QSTR(MP_QSTR_isconnected), MP_ROM_PTR(&wiznet5k_isconnected_obj) },
+    { MP_ROM_QSTR(MP_QSTR_active), MP_ROM_PTR(&wiznet5k_active_obj) },
+    { MP_ROM_QSTR(MP_QSTR_ifconfig), MP_ROM_PTR(&wiznet5k_ifconfig_obj) },
+    { MP_ROM_QSTR(MP_QSTR_status), MP_ROM_PTR(&wiznet5k_status_obj) },
+    { MP_ROM_QSTR(MP_QSTR_config), MP_ROM_PTR(&wiznet5k_config_obj) },
+
+    { MP_ROM_QSTR(MP_QSTR_send_ethernet), MP_ROM_PTR(&send_ethernet_obj) },
+};
+STATIC MP_DEFINE_CONST_DICT(wiznet5k_locals_dict, wiznet5k_locals_dict_table);
+
+const mp_obj_type_t mod_network_nic_type_wiznet5k = {
+    { &mp_type_type },
+    .name = MP_QSTR_WIZNET5K,
+    .make_new = wiznet5k_make_new,
+    .locals_dict = (mp_obj_dict_t*)&wiznet5k_locals_dict,
+};
+
+#endif // MICROPY_PY_WIZNET5K && MICROPY_PY_LWIP