hw/net: Add npcm7xx emc model

This is a 10/100 ethernet device that has several features.
Only the ones needed by the Linux driver have been implemented.
See npcm7xx_emc.c for a list of unimplemented features.

Reviewed-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Avi Fishman <avi.fishman@nuvoton.com>
Signed-off-by: Doug Evans <dje@google.com>
Message-id: 20210218212453.831406-2-dje@google.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 286 insertions, 0 deletions

diff --git a/include/hw/net/npcm7xx_emc.h b/include/hw/net/npcm7xx_emc.h
new file mode 100644
index 0000000000..eac7f29816
--- /dev/null
+++ b/include/hw/net/npcm7xx_emc.h
@@ -0,0 +1,286 @@
+/*
+ * Nuvoton NPCM7xx EMC Module
+ *
+ * Copyright 2020 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#ifndef NPCM7XX_EMC_H
+#define NPCM7XX_EMC_H
+
+#include "hw/irq.h"
+#include "hw/sysbus.h"
+#include "net/net.h"
+
+/* 32-bit register indices. */
+enum NPCM7xxPWMRegister {
+    /* Control registers. */
+    REG_CAMCMR,
+    REG_CAMEN,
+
+    /* There are 16 CAMn[ML] registers. */
+    REG_CAMM_BASE,
+    REG_CAML_BASE,
+    REG_CAMML_LAST = 0x21,
+
+    REG_TXDLSA = 0x22,
+    REG_RXDLSA,
+    REG_MCMDR,
+    REG_MIID,
+    REG_MIIDA,
+    REG_FFTCR,
+    REG_TSDR,
+    REG_RSDR,
+    REG_DMARFC,
+    REG_MIEN,
+
+    /* Status registers. */
+    REG_MISTA,
+    REG_MGSTA,
+    REG_MPCNT,
+    REG_MRPC,
+    REG_MRPCC,
+    REG_MREPC,
+    REG_DMARFS,
+    REG_CTXDSA,
+    REG_CTXBSA,
+    REG_CRXDSA,
+    REG_CRXBSA,
+
+    NPCM7XX_NUM_EMC_REGS,
+};
+
+/* REG_CAMCMR fields */
+/* Enable CAM Compare */
+#define REG_CAMCMR_ECMP (1 << 4)
+/* Complement CAM Compare */
+#define REG_CAMCMR_CCAM (1 << 3)
+/* Accept Broadcast Packet */
+#define REG_CAMCMR_ABP (1 << 2)
+/* Accept Multicast Packet */
+#define REG_CAMCMR_AMP (1 << 1)
+/* Accept Unicast Packet */
+#define REG_CAMCMR_AUP (1 << 0)
+
+/* REG_MCMDR fields */
+/* Software Reset */
+#define REG_MCMDR_SWR (1 << 24)
+/* Internal Loopback Select */
+#define REG_MCMDR_LBK (1 << 21)
+/* Operation Mode Select */
+#define REG_MCMDR_OPMOD (1 << 20)
+/* Enable MDC Clock Generation */
+#define REG_MCMDR_ENMDC (1 << 19)
+/* Full-Duplex Mode Select */
+#define REG_MCMDR_FDUP (1 << 18)
+/* Enable SQE Checking */
+#define REG_MCMDR_ENSEQ (1 << 17)
+/* Send PAUSE Frame */
+#define REG_MCMDR_SDPZ (1 << 16)
+/* No Defer */
+#define REG_MCMDR_NDEF (1 << 9)
+/* Frame Transmission On */
+#define REG_MCMDR_TXON (1 << 8)
+/* Strip CRC Checksum */
+#define REG_MCMDR_SPCRC (1 << 5)
+/* Accept CRC Error Packet */
+#define REG_MCMDR_AEP (1 << 4)
+/* Accept Control Packet */
+#define REG_MCMDR_ACP (1 << 3)
+/* Accept Runt Packet */
+#define REG_MCMDR_ARP (1 << 2)
+/* Accept Long Packet */
+#define REG_MCMDR_ALP (1 << 1)
+/* Frame Reception On */
+#define REG_MCMDR_RXON (1 << 0)
+
+/* REG_MIEN fields */
+/* Enable Transmit Descriptor Unavailable Interrupt */
+#define REG_MIEN_ENTDU (1 << 23)
+/* Enable Transmit Completion Interrupt */
+#define REG_MIEN_ENTXCP (1 << 18)
+/* Enable Transmit Interrupt */
+#define REG_MIEN_ENTXINTR (1 << 16)
+/* Enable Receive Descriptor Unavailable Interrupt */
+#define REG_MIEN_ENRDU (1 << 10)
+/* Enable Receive Good Interrupt */
+#define REG_MIEN_ENRXGD (1 << 4)
+/* Enable Receive Interrupt */
+#define REG_MIEN_ENRXINTR (1 << 0)
+
+/* REG_MISTA fields */
+/* TODO: Add error fields and support simulated errors? */
+/* Transmit Bus Error Interrupt */
+#define REG_MISTA_TXBERR (1 << 24)
+/* Transmit Descriptor Unavailable Interrupt */
+#define REG_MISTA_TDU (1 << 23)
+/* Transmit Completion Interrupt */
+#define REG_MISTA_TXCP (1 << 18)
+/* Transmit Interrupt */
+#define REG_MISTA_TXINTR (1 << 16)
+/* Receive Bus Error Interrupt */
+#define REG_MISTA_RXBERR (1 << 11)
+/* Receive Descriptor Unavailable Interrupt */
+#define REG_MISTA_RDU (1 << 10)
+/* DMA Early Notification Interrupt */
+#define REG_MISTA_DENI (1 << 9)
+/* Maximum Frame Length Interrupt */
+#define REG_MISTA_DFOI (1 << 8)
+/* Receive Good Interrupt */
+#define REG_MISTA_RXGD (1 << 4)
+/* Packet Too Long Interrupt */
+#define REG_MISTA_PTLE (1 << 3)
+/* Receive Interrupt */
+#define REG_MISTA_RXINTR (1 << 0)
+
+/* REG_MGSTA fields */
+/* Transmission Halted */
+#define REG_MGSTA_TXHA (1 << 11)
+/* Receive Halted */
+#define REG_MGSTA_RXHA (1 << 11)
+
+/* REG_DMARFC fields */
+/* Maximum Receive Frame Length */
+#define REG_DMARFC_RXMS(word) extract32((word), 0, 16)
+
+/* REG MIIDA fields */
+/* Busy Bit */
+#define REG_MIIDA_BUSY (1 << 17)
+
+/* Transmit and receive descriptors */
+typedef struct NPCM7xxEMCTxDesc NPCM7xxEMCTxDesc;
+typedef struct NPCM7xxEMCRxDesc NPCM7xxEMCRxDesc;
+
+struct NPCM7xxEMCTxDesc {
+    uint32_t flags;
+    uint32_t txbsa;
+    uint32_t status_and_length;
+    uint32_t ntxdsa;
+};
+
+struct NPCM7xxEMCRxDesc {
+    uint32_t status_and_length;
+    uint32_t rxbsa;
+    uint32_t reserved;
+    uint32_t nrxdsa;
+};
+
+/* NPCM7xxEMCTxDesc.flags values */
+/* Owner: 0 = cpu, 1 = emc */
+#define TX_DESC_FLAG_OWNER_MASK (1 << 31)
+/* Transmit interrupt enable */
+#define TX_DESC_FLAG_INTEN (1 << 2)
+/* CRC append */
+#define TX_DESC_FLAG_CRCAPP (1 << 1)
+/* Padding enable */
+#define TX_DESC_FLAG_PADEN (1 << 0)
+
+/* NPCM7xxEMCTxDesc.status_and_length values */
+/* Collision count */
+#define TX_DESC_STATUS_CCNT_SHIFT 28
+#define TX_DESC_STATUS_CCNT_BITSIZE 4
+/* SQE error */
+#define TX_DESC_STATUS_SQE (1 << 26)
+/* Transmission paused */
+#define TX_DESC_STATUS_PAU (1 << 25)
+/* P transmission halted */
+#define TX_DESC_STATUS_TXHA (1 << 24)
+/* Late collision */
+#define TX_DESC_STATUS_LC (1 << 23)
+/* Transmission abort */
+#define TX_DESC_STATUS_TXABT (1 << 22)
+/* No carrier sense */
+#define TX_DESC_STATUS_NCS (1 << 21)
+/* Defer exceed */
+#define TX_DESC_STATUS_EXDEF (1 << 20)
+/* Transmission complete */
+#define TX_DESC_STATUS_TXCP (1 << 19)
+/* Transmission deferred */
+#define TX_DESC_STATUS_DEF (1 << 17)
+/* Transmit interrupt */
+#define TX_DESC_STATUS_TXINTR (1 << 16)
+
+#define TX_DESC_PKT_LEN(word) extract32((word), 0, 16)
+
+/* Transmit buffer start address */
+#define TX_DESC_TXBSA(word) ((uint32_t) (word) & ~3u)
+
+/* Next transmit descriptor start address */
+#define TX_DESC_NTXDSA(word) ((uint32_t) (word) & ~3u)
+
+/* NPCM7xxEMCRxDesc.status_and_length values */
+/* Owner: 0b00 = cpu, 0b01 = undefined, 0b10 = emc, 0b11 = undefined */
+#define RX_DESC_STATUS_OWNER_SHIFT 30
+#define RX_DESC_STATUS_OWNER_BITSIZE 2
+#define RX_DESC_STATUS_OWNER_MASK (3 << RX_DESC_STATUS_OWNER_SHIFT)
+/* Runt packet */
+#define RX_DESC_STATUS_RP (1 << 22)
+/* Alignment error */
+#define RX_DESC_STATUS_ALIE (1 << 21)
+/* Frame reception complete */
+#define RX_DESC_STATUS_RXGD (1 << 20)
+/* Packet too long */
+#define RX_DESC_STATUS_PTLE (1 << 19)
+/* CRC error */
+#define RX_DESC_STATUS_CRCE (1 << 17)
+/* Receive interrupt */
+#define RX_DESC_STATUS_RXINTR (1 << 16)
+
+#define RX_DESC_PKT_LEN(word) extract32((word), 0, 16)
+
+/* Receive buffer start address */
+#define RX_DESC_RXBSA(word) ((uint32_t) (word) & ~3u)
+
+/* Next receive descriptor start address */
+#define RX_DESC_NRXDSA(word) ((uint32_t) (word) & ~3u)
+
+/* Minimum packet length, when TX_DESC_FLAG_PADEN is set. */
+#define MIN_PACKET_LENGTH 64
+
+struct NPCM7xxEMCState {
+    /*< private >*/
+    SysBusDevice parent;
+    /*< public >*/
+
+    MemoryRegion iomem;
+
+    qemu_irq tx_irq;
+    qemu_irq rx_irq;
+
+    NICState *nic;
+    NICConf conf;
+
+    /* 0 or 1, for log messages */
+    uint8_t emc_num;
+
+    uint32_t regs[NPCM7XX_NUM_EMC_REGS];
+
+    /*
+     * tx is active. Set to true by TSDR and then switches off when out of
+     * descriptors. If the TXON bit in REG_MCMDR is off then this is off.
+     */
+    bool tx_active;
+
+    /*
+     * rx is active. Set to true by RSDR and then switches off when out of
+     * descriptors. If the RXON bit in REG_MCMDR is off then this is off.
+     */
+    bool rx_active;
+};
+
+typedef struct NPCM7xxEMCState NPCM7xxEMCState;
+
+#define TYPE_NPCM7XX_EMC "npcm7xx-emc"
+#define NPCM7XX_EMC(obj) \
+    OBJECT_CHECK(NPCM7xxEMCState, (obj), TYPE_NPCM7XX_EMC)
+
+#endif /* NPCM7XX_EMC_H */