myson.c

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/*
 * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <byteswap.h>
#include <ipxe/netdevice.h>
#include <ipxe/ethernet.h>
#include <ipxe/if_ether.h>
#include <ipxe/iobuf.h>
#include <ipxe/malloc.h>
#include <ipxe/pci.h>
#include <ipxe/mii.h>
#include "myson.h"

/** @file
 *
 * Myson Technology network card driver
 *
 */

/******************************************************************************
 *
 * Device reset
 *
 ******************************************************************************
 */

/**
 * Reset controller chip
 *
 * @v myson             Myson device
 * @ret rc              Return status code
 */
static int myson_soft_reset ( struct myson_nic *myson ) {
        uint32_t bcr;
        unsigned int i;

        /* Initiate reset */
        bcr = readl ( myson->regs + MYSON_BCR );
        writel ( ( bcr | MYSON_BCR_SWR ), myson->regs + MYSON_BCR );

        /* Wait for reset to complete */
        for ( i = 0 ; i < MYSON_RESET_MAX_WAIT_MS ; i++ ) {

                /* If reset is not complete, delay 1ms and retry */
                if ( readl ( myson->regs + MYSON_BCR ) & MYSON_BCR_SWR ) {
                        mdelay ( 1 );
                        continue;
                }

                /* Apply a sensible default bus configuration */
                bcr = readl ( myson->regs + MYSON_BCR );
                bcr &= ~MYSON_BCR_PBL_MASK;
                bcr |= ( MYSON_BCR_RLE | MYSON_BCR_RME | MYSON_BCR_WIE |
                         MYSON_BCR_PBL_DEFAULT );
                writel ( bcr, myson->regs + MYSON_BCR );
                DBGC ( myson, "MYSON %p using configuration %08x\n",
                       myson, bcr );

                return 0;
        }

        DBGC ( myson, "MYSON %p timed out waiting for reset\n", myson );
        return -ETIMEDOUT;
}

/**
 * Reload configuration from EEPROM
 *
 * @v myson             Myson device
 * @ret rc              Return status code
 */
static int myson_reload_config ( struct myson_nic *myson ) {
        unsigned int i;

        /* Initiate reload */
        writel ( MYSON_ROM_AUTOLD, myson->regs + MYSON_ROM_MII );

        /* Wait for reload to complete */
        for ( i = 0 ; i < MYSON_AUTOLD_MAX_WAIT_MS ; i++ ) {

                /* If reload is not complete, delay 1ms and retry */
                if ( readl ( myson->regs + MYSON_ROM_MII ) & MYSON_ROM_AUTOLD ){
                        mdelay ( 1 );
                        continue;
                }

                return 0;
        }

        DBGC ( myson, "MYSON %p timed out waiting for configuration "
               "reload\n", myson );
        return -ETIMEDOUT;
}

/**
 * Reset hardware
 *
 * @v myson             Myson device
 * @ret rc              Return status code
 */
static int myson_reset ( struct myson_nic *myson ) {
        int rc;

        /* Disable all interrupts */
        writel ( 0, myson->regs + MYSON_IMR );

        /* Perform soft reset */
        if ( ( rc = myson_soft_reset ( myson ) ) != 0 )
                return rc;

        /* Reload configuration from EEPROM */
        if ( ( rc = myson_reload_config ( myson ) ) != 0 )
                return rc;

        return 0;
}

/******************************************************************************
 *
 * Network device interface
 *
 ******************************************************************************
 */

/**
 * Create descriptor ring
 *
 * @v myson             Myson device
 * @v ring              Descriptor ring
 * @ret rc              Return status code
 */
static int myson_create_ring ( struct myson_nic *myson,
                               struct myson_ring *ring ) {
        size_t len = ( ring->count * sizeof ( ring->desc[0] ) );
        struct myson_descriptor *desc;
        struct myson_descriptor *next;
        physaddr_t address;
        unsigned int i;
        int rc;

        /* Allocate descriptor ring */
        ring->desc = malloc_phys ( len, MYSON_RING_ALIGN );
        if ( ! ring->desc ) {
                rc = -ENOMEM;
                goto err_alloc;
        }
        address = virt_to_bus ( ring->desc );

        /* Check address is usable by card */
        if ( ! myson_address_ok ( address + len ) ) {
                DBGC ( myson, "MYSON %p cannot support 64-bit ring address\n",
                       myson );
                rc = -ENOTSUP;
                goto err_64bit;
        }

        /* Initialise descriptor ring */
        memset ( ring->desc, 0, len );
        for ( i = 0 ; i < ring->count ; i++ ) {
                desc = &ring->desc[i];
                next = &ring->desc[ ( i + 1 ) % ring->count ];
                desc->next = cpu_to_le32 ( virt_to_bus ( next ) );
        }

        /* Program ring address */
        writel ( address, myson->regs + ring->reg );
        DBGC ( myson, "MYSON %p ring %02x is at [%08llx,%08llx)\n",
               myson, ring->reg, ( ( unsigned long long ) address ),
               ( ( unsigned long long ) address + len ) );

        return 0;

 err_64bit:
        free_phys ( ring->desc, len );
        ring->desc = NULL;
 err_alloc:
        return rc;
}

/**
 * Destroy descriptor ring
 *
 * @v myson             Myson device
 * @v ring              Descriptor ring
 */
static void myson_destroy_ring ( struct myson_nic *myson,
                                 struct myson_ring *ring ) {
        size_t len = ( ring->count * sizeof ( ring->desc[0] ) );

        /* Clear ring address */
        writel ( 0, myson->regs + ring->reg );

        /* Free descriptor ring */
        free_phys ( ring->desc, len );
        ring->desc = NULL;
        ring->prod = 0;
        ring->cons = 0;
}

/**
 * Refill receive descriptor ring
 *
 * @v netdev            Network device
 */
static void myson_refill_rx ( struct net_device *netdev ) {
        struct myson_nic *myson = netdev->priv;
        struct myson_descriptor *rx;
        struct io_buffer *iobuf;
        unsigned int rx_idx;
        physaddr_t address;

        while ( ( myson->rx.prod - myson->rx.cons ) < MYSON_NUM_RX_DESC ) {

                /* Allocate I/O buffer */
                iobuf = alloc_iob ( MYSON_RX_MAX_LEN );
                if ( ! iobuf ) {
                        /* Wait for next refill */
                        return;
                }

                /* Check address is usable by card */
                address = virt_to_bus ( iobuf->data );
                if ( ! myson_address_ok ( address ) ) {
                        DBGC ( myson, "MYSON %p cannot support 64-bit RX "
                               "buffer address\n", myson );
                        netdev_rx_err ( netdev, iobuf, -ENOTSUP );
                        return;
                }

                /* Get next receive descriptor */
                rx_idx = ( myson->rx.prod++ % MYSON_NUM_RX_DESC );
                rx = &myson->rx.desc[rx_idx];

                /* Populate receive descriptor */
                rx->address = cpu_to_le32 ( address );
                rx->control =
                        cpu_to_le32 ( MYSON_RX_CTRL_RBS ( MYSON_RX_MAX_LEN ) );
                wmb();
                rx->status = cpu_to_le32 ( MYSON_RX_STAT_OWN );
                wmb();

                /* Record I/O buffer */
                assert ( myson->rx_iobuf[rx_idx] == NULL );
                myson->rx_iobuf[rx_idx] = iobuf;

                /* Notify card that there are descriptors available */
                writel ( 0, myson->regs + MYSON_RXPDR );

                DBGC2 ( myson, "MYSON %p RX %d is [%llx,%llx)\n", myson,
                        rx_idx, ( ( unsigned long long ) address ),
                        ( ( unsigned long long ) address + MYSON_RX_MAX_LEN ) );
        }
}

/**
 * Open network device
 *
 * @v netdev            Network device
 * @ret rc              Return status code
 */
static int myson_open ( struct net_device *netdev ) {
        struct myson_nic *myson = netdev->priv;
        union myson_physical_address mac;
        int rc;

        /* Set MAC address */
        memset ( &mac, 0, sizeof ( mac ) );
        memcpy ( mac.raw, netdev->ll_addr, ETH_ALEN );
        writel ( le32_to_cpu ( mac.reg.low ), myson->regs + MYSON_PAR0 );
        writel ( le32_to_cpu ( mac.reg.high ), myson->regs + MYSON_PAR4 );

        /* Create transmit descriptor ring */
        if ( ( rc = myson_create_ring ( myson, &myson->tx ) ) != 0 )
                goto err_create_tx;

        /* Create receive descriptor ring */
        if ( ( rc = myson_create_ring ( myson, &myson->rx ) ) != 0 )
                goto err_create_rx;

        /* Configure transmitter and receiver */
        writel ( ( MYSON_TCR_TE | MYSON_RCR_PROM | MYSON_RCR_AB | MYSON_RCR_AM |
                   MYSON_RCR_ARP | MYSON_RCR_ALP | MYSON_RCR_RE ),
                 myson->regs + MYSON_TCR_RCR );

        /* Fill receive ring */
        myson_refill_rx ( netdev );

        return 0;

        myson_destroy_ring ( myson, &myson->rx );
 err_create_rx:
        myson_destroy_ring ( myson, &myson->tx );
 err_create_tx:
        return rc;
}

/**
 * Wait for transmit and receive to become idle
 *
 * @v myson             Myson device
 * @ret rc              Return status code
 */
static int myson_wait_idle ( struct myson_nic *myson ) {
        uint32_t tcr_rcr;
        unsigned int i;

        /* Wait for both transmit and receive to be idle */
        for ( i = 0 ; i < MYSON_IDLE_MAX_WAIT_MS ; i++ ) {

                /* If either process is running, delay 1ms and retry */
                tcr_rcr = readl ( myson->regs + MYSON_TCR_RCR );
                if ( tcr_rcr & ( MYSON_TCR_TXS | MYSON_RCR_RXS ) ) {
                        mdelay ( 1 );
                        continue;
                }

                return 0;
        }

        DBGC ( myson, "MYSON %p timed out waiting for idle state (status "
               "%08x)\n", myson, tcr_rcr );
        return -ETIMEDOUT;
}

/**
 * Close network device
 *
 * @v netdev            Network device
 */
static void myson_close ( struct net_device *netdev ) {
        struct myson_nic *myson = netdev->priv;
        unsigned int i;

        /* Disable receiver and transmitter */
        writel ( 0, myson->regs + MYSON_TCR_RCR );

        /* Allow time for receiver and transmitter to become idle */
        myson_wait_idle ( myson );

        /* Destroy receive descriptor ring */
        myson_destroy_ring ( myson, &myson->rx );

        /* Discard any unused receive buffers */
        for ( i = 0 ; i < MYSON_NUM_RX_DESC ; i++ ) {
                if ( myson->rx_iobuf[i] )
                        free_iob ( myson->rx_iobuf[i] );
                myson->rx_iobuf[i] = NULL;
        }

        /* Destroy transmit descriptor ring */
        myson_destroy_ring ( myson, &myson->tx );
}

/**
 * Transmit packet
 *
 * @v netdev            Network device
 * @v iobuf             I/O buffer
 * @ret rc              Return status code
 */
static int myson_transmit ( struct net_device *netdev,
                            struct io_buffer *iobuf ) {
        struct myson_nic *myson = netdev->priv;
        struct myson_descriptor *tx;
        unsigned int tx_idx;
        physaddr_t address;

        /* Check address is usable by card */
        address = virt_to_bus ( iobuf->data );
        if ( ! myson_address_ok ( address ) ) {
                DBGC ( myson, "MYSON %p cannot support 64-bit TX buffer "
                       "address\n", myson );
                return -ENOTSUP;
        }

        /* Get next transmit descriptor */
        if ( ( myson->tx.prod - myson->tx.cons ) >= MYSON_NUM_TX_DESC ) {
                DBGC ( myson, "MYSON %p out of transmit descriptors\n",
                       myson );
                return -ENOBUFS;
        }
        tx_idx = ( myson->tx.prod++ % MYSON_NUM_TX_DESC );
        tx = &myson->tx.desc[tx_idx];

        /* Populate transmit descriptor */
        tx->address = cpu_to_le32 ( address );
        tx->control = cpu_to_le32 ( MYSON_TX_CTRL_IC | MYSON_TX_CTRL_LD |
                                    MYSON_TX_CTRL_FD | MYSON_TX_CTRL_CRC |
                                    MYSON_TX_CTRL_PAD | MYSON_TX_CTRL_RTLC |
                                    MYSON_TX_CTRL_PKTS ( iob_len ( iobuf ) ) |
                                    MYSON_TX_CTRL_TBS ( iob_len ( iobuf ) ) );
        wmb();
        tx->status = cpu_to_le32 ( MYSON_TX_STAT_OWN );
        wmb();

        /* Notify card that there are packets ready to transmit */
        writel ( 0, myson->regs + MYSON_TXPDR );

        DBGC2 ( myson, "MYSON %p TX %d is [%llx,%llx)\n", myson, tx_idx,
                ( ( unsigned long long ) address ),
                ( ( unsigned long long ) address + iob_len ( iobuf ) ) );

        return 0;
}

/**
 * Poll for completed packets
 *
 * @v netdev            Network device
 */
static void myson_poll_tx ( struct net_device *netdev ) {
        struct myson_nic *myson = netdev->priv;
        struct myson_descriptor *tx;
        unsigned int tx_idx;

        /* Check for completed packets */
        while ( myson->tx.cons != myson->tx.prod ) {

                /* Get next transmit descriptor */
                tx_idx = ( myson->tx.cons % MYSON_NUM_TX_DESC );
                tx = &myson->tx.desc[tx_idx];

                /* Stop if descriptor is still in use */
                if ( tx->status & cpu_to_le32 ( MYSON_TX_STAT_OWN ) )
                        return;

                /* Complete TX descriptor */
                if ( tx->status & cpu_to_le32 ( MYSON_TX_STAT_ABORT |
                                                MYSON_TX_STAT_CSL ) ) {
                        DBGC ( myson, "MYSON %p TX %d completion error "
                               "(%08x)\n", myson, tx_idx,
                               le32_to_cpu ( tx->status ) );
                        netdev_tx_complete_next_err ( netdev, -EIO );
                } else {
                        DBGC2 ( myson, "MYSON %p TX %d complete\n",
                                myson, tx_idx );
                        netdev_tx_complete_next ( netdev );
                }
                myson->tx.cons++;
        }
}

/**
 * Poll for received packets
 *
 * @v netdev            Network device
 */
static void myson_poll_rx ( struct net_device *netdev ) {
        struct myson_nic *myson = netdev->priv;
        struct myson_descriptor *rx;
        struct io_buffer *iobuf;
        unsigned int rx_idx;
        size_t len;

        /* Check for received packets */
        while ( myson->rx.cons != myson->rx.prod ) {

                /* Get next receive descriptor */
                rx_idx = ( myson->rx.cons % MYSON_NUM_RX_DESC );
                rx = &myson->rx.desc[rx_idx];

                /* Stop if descriptor is still in use */
                if ( rx->status & MYSON_RX_STAT_OWN )
                        return;

                /* Populate I/O buffer */
                iobuf = myson->rx_iobuf[rx_idx];
                myson->rx_iobuf[rx_idx] = NULL;
                len = MYSON_RX_STAT_FLNG ( le32_to_cpu ( rx->status ) );
                iob_put ( iobuf, len - 4 /* strip CRC */ );

                /* Hand off to network stack */
                if ( rx->status & cpu_to_le32 ( MYSON_RX_STAT_ES ) ) {
                        DBGC ( myson, "MYSON %p RX %d error (length %zd, "
                               "status %08x)\n", myson, rx_idx, len,
                               le32_to_cpu ( rx->status ) );
                        netdev_rx_err ( netdev, iobuf, -EIO );
                } else {
                        DBGC2 ( myson, "MYSON %p RX %d complete (length "
                                "%zd)\n", myson, rx_idx, len );
                        netdev_rx ( netdev, iobuf );
                }
                myson->rx.cons++;
        }
}

/**
 * Poll for completed and received packets
 *
 * @v netdev            Network device
 */
static void myson_poll ( struct net_device *netdev ) {
        struct myson_nic *myson = netdev->priv;
        uint32_t isr;
        unsigned int i;

        /* Polling the ISR seems to really upset this card; it ends up
         * getting no useful PCI transfers done and, for some reason,
         * flooding the network with invalid packets.  Work around
         * this by introducing deliberate delays between ISR reads.
         */
        for ( i = 0 ; i < MYSON_ISR_IODELAY_COUNT ; i++ )
                iodelay();

        /* Check for and acknowledge interrupts */
        isr = readl ( myson->regs + MYSON_ISR );
        if ( ! isr )
                return;
        writel ( isr, myson->regs + MYSON_ISR );

        /* Poll for TX completions, if applicable */
        if ( isr & MYSON_IRQ_TI )
                myson_poll_tx ( netdev );

        /* Poll for RX completionsm, if applicable */
        if ( isr & MYSON_IRQ_RI )
                myson_poll_rx ( netdev );

        /* Refill RX ring */
        myson_refill_rx ( netdev );
}

/**
 * Enable or disable interrupts
 *
 * @v netdev            Network device
 * @v enable            Interrupts should be enabled
 */
static void myson_irq ( struct net_device *netdev, int enable ) {
        struct myson_nic *myson = netdev->priv;
        uint32_t imr;

        imr = ( enable ? ( MYSON_IRQ_TI | MYSON_IRQ_RI ) : 0 );
        writel ( imr, myson->regs + MYSON_IMR );
}

/** Myson network device operations */
static struct net_device_operations myson_operations = {
        .open           = myson_open,
        .close          = myson_close,
        .transmit       = myson_transmit,
        .poll           = myson_poll,
        .irq            = myson_irq,
};

/******************************************************************************
 *
 * PCI interface
 *
 ******************************************************************************
 */

/**
 * Probe PCI device
 *
 * @v pci               PCI device
 * @ret rc              Return status code
 */
static int myson_probe ( struct pci_device *pci ) {
        struct net_device *netdev;
        struct myson_nic *myson;
        union myson_physical_address mac;
        int rc;

        /* Allocate and initialise net device */
        netdev = alloc_etherdev ( sizeof ( *myson ) );
        if ( ! netdev ) {
                rc = -ENOMEM;
                goto err_alloc;
        }
        netdev_init ( netdev, &myson_operations );
        myson = netdev->priv;
        pci_set_drvdata ( pci, netdev );
        netdev->dev = &pci->dev;
        memset ( myson, 0, sizeof ( *myson ) );
        myson_init_ring ( &myson->tx, MYSON_NUM_TX_DESC, MYSON_TXLBA );
        myson_init_ring ( &myson->rx, MYSON_NUM_RX_DESC, MYSON_RXLBA );

        /* Fix up PCI device */
        adjust_pci_device ( pci );

        /* Map registers */
        myson->regs = pci_ioremap ( pci, pci->membase, MYSON_BAR_SIZE );
        if ( ! myson->regs ) {
                rc = -ENODEV;
                goto err_ioremap;
        }

        /* Reset the NIC */
        if ( ( rc = myson_reset ( myson ) ) != 0 )
                goto err_reset;

        /* Read MAC address */
        mac.reg.low = cpu_to_le32 ( readl ( myson->regs + MYSON_PAR0 ) );
        mac.reg.high = cpu_to_le32 ( readl ( myson->regs + MYSON_PAR4 ) );
        memcpy ( netdev->hw_addr, mac.raw, ETH_ALEN );

        /* Register network device */
        if ( ( rc = register_netdev ( netdev ) ) != 0 )
                goto err_register_netdev;

        /* Mark as link up; we don't yet handle link state */
        netdev_link_up ( netdev );

        return 0;

        unregister_netdev ( netdev );
 err_register_netdev:
        myson_reset ( myson );
 err_reset:
        iounmap ( myson->regs );
 err_ioremap:
        netdev_nullify ( netdev );
        netdev_put ( netdev );
 err_alloc:
        return rc;
}

/**
 * Remove PCI device
 *
 * @v pci               PCI device
 */
static void myson_remove ( struct pci_device *pci ) {
        struct net_device *netdev = pci_get_drvdata ( pci );
        struct myson_nic *myson = netdev->priv;

        /* Unregister network device */
        unregister_netdev ( netdev );

        /* Reset card */
        myson_reset ( myson );

        /* Free network device */
        iounmap ( myson->regs );
        netdev_nullify ( netdev );
        netdev_put ( netdev );
}

/** Myson PCI device IDs */
static struct pci_device_id myson_nics[] = {
        PCI_ROM ( 0x1516, 0x0800, "mtd800", "MTD-8xx", 0 ),
        PCI_ROM ( 0x1516, 0x0803, "mtd803", "Surecom EP-320X-S", 0 ),
        PCI_ROM ( 0x1516, 0x0891, "mtd891", "MTD-8xx", 0 ),
};

/** Myson PCI driver */
struct pci_driver myson_driver __pci_driver = {
        .ids = myson_nics,
        .id_count = ( sizeof ( myson_nics ) / sizeof ( myson_nics[0] ) ),
        .probe = myson_probe,
        .remove = myson_remove,
};