// Copyright (c) 2022 Cesanta Software Limited // All rights reserved #include #include #include #include "hardware/dma.h" #include "hardware/pio.h" #include "pico/stdlib.h" #include "driver_rp2040_rmii.h" #include "mongoose.h" #define RXSM 0 #define TXSM 1 #define SMITXSM 2 #define SMIRXSM 0 // pio1 static uint smi_wr_addr, smi_rd_addr; static int dma_rx; static int dma_tx; static dma_channel_config dmacfg_rx; static dma_channel_config dmacfg_tx; // Max frame size with VLAN tag + CRC and excluding preamble #define ETH_PKT_SIZE 1522 static uint8_t s_rxbuf[2][ETH_PKT_SIZE]; // ping-pong buffer static uint8_t s_txbuf[ETH_PKT_SIZE]; static struct mg_tcpip_if *s_ifp; // MIP interface #define rmii_tx_wrap_target 0 #define rmii_tx_wrap 8 static const uint16_t rmii_tx_program_instructions[] = { // .wrap_target 0xe000, // 0: set pins, 0 side 0 0x80a0, // 1: pull block side 0 0xe03d, // 2: set x, 29 side 0 0xf101, // 3: set pins, 1 side 1 [1] 0x1144, // 4: jmp x--, 4 side 1 [1] 0xf103, // 5: set pins, 3 side 1 [1] 0x7002, // 6: out pins, 2 side 1 0x10e6, // 7: jmp !osre, 6 side 1 // .wrap }; static const struct pio_program rmii_tx_program = { .instructions = rmii_tx_program_instructions, .length = 9, .origin = -1, }; static inline pio_sm_config rmii_tx_program_get_default_config(uint addr) { pio_sm_config c = pio_get_default_sm_config(); sm_config_set_wrap(&c, addr + rmii_tx_wrap_target, addr + rmii_tx_wrap); sm_config_set_sideset(&c, 1, false, false); return c; } static inline void rmii_tx_init(PIO pio, uint sm, uint addr, uint gpio) { pio_sm_config c = rmii_tx_program_get_default_config(addr); pio_gpio_init(pio, gpio); pio_gpio_init(pio, gpio + 1); pio_gpio_init(pio, gpio + 2); sm_config_set_out_pins(&c, gpio, 2); sm_config_set_set_pins(&c, gpio, 2); sm_config_set_sideset_pins(&c, gpio + 2); pio_sm_set_consecutive_pindirs(pio, sm, gpio, 3, true); sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX); sm_config_set_out_shift(&c, true, true, 8); // pull bytes, LSB first, auto sm_config_set_clkdiv(&c, 5); // Run at 50/5 = 10MHz (2x 2-bit nibble data rate) pio_sm_init(pio, sm, addr, &c); pio_sm_set_enabled(pio, sm, true); } #define rmii_rx_wrap_target 0 #define rmii_rx_wrap 10 static const uint16_t rmii_rx_program_instructions[] = { // .wrap_target 0x2122, // 0: wait 0 pin, 2 [1] 0x21a2, // 1: wait 1 pin, 2 [1] 0x21a0, // 2: wait 1 pin, 0 [1] 0x2121, // 3: wait 0 pin, 1 [1] 0x21a1, // 4: wait 1 pin, 1 [1] 0x4002, // 5: in pins, 2 0x00c5, // 6: jmp pin, 5 0x4002, // 7: in pins, 2 0x00c5, // 8: jmp pin, 5 0xa0c3, // 9: mov isr, null 0xc020, // 10: irq wait 0 // .wrap }; static const struct pio_program rmii_rx_program = { .instructions = rmii_rx_program_instructions, .length = 11, .origin = -1, }; static inline pio_sm_config rmii_rx_program_get_default_config(uint addr) { pio_sm_config c = pio_get_default_sm_config(); sm_config_set_wrap(&c, addr + rmii_rx_wrap_target, addr + rmii_rx_wrap); return c; } static inline void rmii_rx_init(PIO pio, uint sm, uint addr, uint gpio) { pio_sm_config c = rmii_rx_program_get_default_config(addr); pio_gpio_init(pio, gpio); pio_gpio_init(pio, gpio + 1); pio_gpio_init(pio, gpio + 2); sm_config_set_in_pins(&c, gpio); pio_sm_set_consecutive_pindirs(pio, sm, gpio, 3, false); sm_config_set_jmp_pin(&c, gpio + 2); sm_config_set_in_shift(&c, true, true, 8); // push bytes, LSB first, auto sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_RX); sm_config_set_clkdiv(&c, 5); // Run at 50/5 = 10MHz (2x 2-bit nibble data rate) pio_sm_init(pio, sm, addr, &c); pio_sm_set_enabled(pio, sm, true); } #define smi_wr_wrap_target 0 #define smi_wr_wrap 4 static const uint16_t smi_wr_program_instructions[] = { // .wrap_target 0xe03f, // 0: set x, 31 side 0 0xe101, // 1: set pins, 1 side 0 [1] 0x1141, // 2: jmp x--, 1 side 1 [1] 0x6101, // 3: out pins, 1 side 0 [1] 0x1103, // 4: jmp 3 side 1 [1] // .wrap }; static const struct pio_program smi_wr_program = { .instructions = smi_wr_program_instructions, .length = 5, .origin = -1, }; static inline pio_sm_config smi_wr_program_get_default_config(uint addr) { pio_sm_config c = pio_get_default_sm_config(); sm_config_set_wrap(&c, addr + smi_wr_wrap_target, addr + smi_wr_wrap); sm_config_set_sideset(&c, 1, false, false); return c; } #define smi_rd_wrap_target 13 #define smi_rd_wrap 13 static const uint16_t smi_rd_program_instructions[] = { 0xe03f, // 0: set x, 31 side 0 0xe101, // 1: set pins, 1 side 0 [1] 0x1141, // 2: jmp x--, 1 side 1 [1] 0xf02d, // 3: set x, 13 side 1 0x6101, // 4: out pins, 1 side 0 [1] 0x1144, // 5: jmp x--, 4 side 1 [1] 0xe180, // 6: set pindirs, 0 side 0 [1] 0xf101, // 7: set pins, 1 side 1 [1] 0xa142, // 8: nop side 0 [1] 0xf12f, // 9: set x, 15 side 1 [1] 0xa042, // 10: nop side 0 0x4001, // 11: in pins, 1 side 0 0x114a, // 12: jmp x--, 10 side 1 [1] // .wrap_target 0xf081, // 13: set pindirs, 1 side 1 // .wrap }; static const struct pio_program smi_rd_program = { .instructions = smi_rd_program_instructions, .length = 14, .origin = -1, }; static inline pio_sm_config smi_rd_program_get_default_config(uint addr) { pio_sm_config c = pio_get_default_sm_config(); sm_config_set_wrap(&c, addr + smi_rd_wrap_target, addr + smi_rd_wrap); sm_config_set_sideset(&c, 1, false, false); return c; } static inline void smi_wr_init(PIO pio, uint sm, uint addr, uint gpio) { pio_gpio_init(pio, gpio); pio_gpio_init(pio, gpio + 1); pio_sm_config c = smi_wr_program_get_default_config(addr); sm_config_set_out_pins(&c, gpio, 1); sm_config_set_set_pins(&c, gpio, 1); sm_config_set_sideset_pins(&c, gpio + 1); pio_sm_set_consecutive_pindirs(pio, sm, gpio, 2, true); sm_config_set_out_shift(&c, false, true, 16); // pull half-words, MSB first, auto sm_config_set_clkdiv(&c, 6); // Run at 50/6 = <10MHz (4x data rate) pio_sm_init(pio, sm, addr, &c); } static inline void smi_rd_init(PIO pio, uint sm, uint addr, uint gpio) { pio_gpio_init(pio, gpio); pio_gpio_init(pio, gpio + 1); pio_sm_config c = smi_rd_program_get_default_config(addr); sm_config_set_in_pins(&c, gpio); sm_config_set_out_pins(&c, gpio, 1); sm_config_set_set_pins(&c, gpio, 1); sm_config_set_sideset_pins(&c, gpio + 1); pio_sm_set_consecutive_pindirs(pio, sm, gpio, 2, true); sm_config_set_out_shift(&c, false, true, 16); // pull half-words, MSB first, auto sm_config_set_in_shift(&c, false, true, 16); // push half-words, MSB first, auto sm_config_set_clkdiv(&c, 6); // Run at 50/6 = <10MHz (4x data rate) pio_sm_init(pio, sm, addr, &c); } static void eth_write_phy(int addr, int reg, int val, uint8_t gpio) { uint16_t op = 0x5002 | (addr << 7) | (reg << 2); // b0101aaaaarrrrr10 smi_wr_init(pio0, SMITXSM, smi_wr_addr, gpio); pio_sm_put(pio0, SMITXSM, op << 16); pio_sm_put(pio0, SMITXSM, (uint16_t) val << 16); pio_sm_set_enabled(pio0, SMITXSM, true); } static uint16_t eth_read_phy(uint addr, uint reg, uint8_t gpio) { uint16_t op = 0x6000 | (addr << 7) | (reg << 2); // b0110aaaaarrrrr00 smi_rd_init(pio1, SMIRXSM, smi_rd_addr, gpio); pio_sm_put(pio1, SMIRXSM, op << 16); pio_sm_set_enabled(pio1, SMIRXSM, true); uint16_t val = (uint16_t) pio_sm_get_blocking(pio1, SMIRXSM); pio_sm_set_enabled(pio1, SMIRXSM, false); return val; } static void rx_irq(void); static bool mg_tcpip_driver_rp2040_rmii_init(struct mg_tcpip_if *ifp) { struct mg_tcpip_driver_rp2040_rmii_data *d = (struct mg_tcpip_driver_rp2040_rmii_data *) ifp->driver_data; uint rx_sm_addr, tx_sm_addr; s_ifp = ifp; rx_sm_addr = pio_add_program(pio0, &rmii_rx_program); tx_sm_addr = pio_add_program(pio0, &rmii_tx_program); smi_wr_addr = pio_add_program(pio0, &smi_wr_program); smi_rd_addr = pio_add_program(pio1, &smi_rd_program); dma_tx = dma_claim_unused_channel(true); dmacfg_tx = dma_channel_get_default_config(dma_tx); channel_config_set_read_increment(&dmacfg_tx, true); // read from memory channel_config_set_write_increment(&dmacfg_tx, false); // write to FIFO channel_config_set_dreq(&dmacfg_tx, pio_get_dreq(pio0, TXSM, true)); channel_config_set_transfer_data_size(&dmacfg_tx, DMA_SIZE_8); // transfer bytes rmii_tx_init(pio0, TXSM, tx_sm_addr, d->tx0); eth_write_phy(d->phy_addr, 4, 0x61, d->mdio); // Auto Negotiation Advertisement Register: enable // only 10BASE-T full and half duplex (two-pair), use // IEEE 802.3 format sleep_us(31); // give some time for PIO to work (64 bits @2.5MHz = 25.6 us) eth_write_phy(d->phy_addr, 0, 0x1000, d->mdio); // Basic Control Register: enable Auto-Negotiation sleep_us(31); dma_rx = dma_claim_unused_channel(true); dmacfg_rx = dma_channel_get_default_config(dma_rx); channel_config_set_read_increment(&dmacfg_rx, false); // read from FIFO channel_config_set_write_increment(&dmacfg_rx, true); // write to memory, increment channel_config_set_dreq(&dmacfg_rx, pio_get_dreq(pio0, RXSM, false)); channel_config_set_transfer_data_size(&dmacfg_rx, DMA_SIZE_8); // transfer bytes dma_channel_configure(dma_rx, &dmacfg_rx, s_rxbuf[0], ((uint8_t *) &pio0->rxf[RXSM]) + 3, ETH_PKT_SIZE, true); pio_set_irq0_source_enabled(pio0, pis_interrupt0, true); // enable SM0 on PIO0_IRQ_0 irq_set_exclusive_handler(7, rx_irq); // set handler for PIO0_IRQ_0 irq_set_enabled(7, true); // enable it rmii_rx_init(pio0, RXSM, rx_sm_addr, d->rx0); return true; } static size_t mg_tcpip_driver_rp2040_rmii_tx(const void *buf, size_t len, struct mg_tcpip_if *ifp) { dma_channel_wait_for_finish_blocking(dma_tx); memset(s_txbuf, 0, 60); // pre-pad memcpy(s_txbuf, buf, len); if (len < 60) len = 60; // pad uint32_t crc = mg_crc32(0, s_txbuf, len); // host is little-endian memcpy(s_txbuf + len, (uint8_t *) &crc, 4); len += 4; sleep_us(10); // enforce IFG in case software has been lightning fast... dma_channel_configure(dma_tx, &dmacfg_tx, ((uint8_t *) &pio0->txf[TXSM]) + 3, s_txbuf, len, true); return len; } static uint32_t s_rxno; // The max amount of time we should keep the PIO state machine stopped is the // IFG time (10us) and that includes irq latency static void rx_irq(void) { dma_channel_hw_t *hw = dma_channel_hw_addr(dma_rx); uint32_t rxno = (s_rxno + 1) & 1; // 2 buffers, switch to the available one as fast as possible size_t len = ETH_PKT_SIZE - hw->transfer_count; dma_channel_abort(dma_rx); dma_channel_set_write_addr(dma_rx, s_rxbuf[rxno], true); // restart DMA pio_interrupt_clear(pio0, 0); // ACK PIO IRQ so the state machine resumes receiving // NOTE(scaprile) Here we could check addressing to avoid queuing frames not // for us. The max amount of time we can linger here is what it takes for the // other buffer to fill (<8us) and that includes irq chaining if (len >= 64 && len <= ETH_PKT_SIZE) mg_tcpip_qwrite(s_rxbuf[s_rxno], len, s_ifp); s_rxno = rxno; } static bool mg_tcpip_driver_rp2040_rmii_up(struct mg_tcpip_if *ifp) { struct mg_tcpip_driver_rp2040_rmii_data *d = (struct mg_tcpip_driver_rp2040_rmii_data *) ifp->driver_data; uint32_t bsr = eth_read_phy(d->phy_addr, 1, d->mdio); // Basic Status Register return (bsr & (1 << 2)) ? 1 : 0; // check Link Status flag } struct mg_tcpip_driver mg_tcpip_driver_rp2040_rmii = { mg_tcpip_driver_rp2040_rmii_init, mg_tcpip_driver_rp2040_rmii_tx, NULL, mg_tcpip_driver_rp2040_rmii_up, };