diff options
Diffstat (limited to 'drivers/net/can/mscan/mscan.c')
| -rw-r--r-- | drivers/net/can/mscan/mscan.c | 679 |
1 files changed, 679 insertions, 0 deletions
diff --git a/drivers/net/can/mscan/mscan.c b/drivers/net/can/mscan/mscan.c new file mode 100644 index 000000000000..fe42b9e7dfb7 --- /dev/null +++ b/drivers/net/can/mscan/mscan.c @@ -0,0 +1,679 @@ +/* + * CAN bus driver for the alone generic (as possible as) MSCAN controller. + * + * Copyright (C) 2005-2006 Andrey Volkov <avolkov@varma-el.com>, + * Varma Electronics Oy + * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the version 2 of the GNU General Public License + * as published by the Free Software Foundation + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/netdevice.h> +#include <linux/if_arp.h> +#include <linux/if_ether.h> +#include <linux/list.h> +#include <linux/can.h> +#include <linux/can/dev.h> +#include <linux/can/error.h> +#include <linux/io.h> + +#include "mscan.h" + +#define MSCAN_NORMAL_MODE 0 +#define MSCAN_SLEEP_MODE MSCAN_SLPRQ +#define MSCAN_INIT_MODE (MSCAN_INITRQ | MSCAN_SLPRQ) +#define MSCAN_POWEROFF_MODE (MSCAN_CSWAI | MSCAN_SLPRQ) +#define MSCAN_SET_MODE_RETRIES 255 + +#define BTR0_BRP_MASK 0x3f +#define BTR0_SJW_SHIFT 6 +#define BTR0_SJW_MASK (0x3 << BTR0_SJW_SHIFT) + +#define BTR1_TSEG1_MASK 0xf +#define BTR1_TSEG2_SHIFT 4 +#define BTR1_TSEG2_MASK (0x7 << BTR1_TSEG2_SHIFT) +#define BTR1_SAM_SHIFT 7 + +#define BTR0_SET_BRP(brp) (((brp) - 1) & BTR0_BRP_MASK) +#define BTR0_SET_SJW(sjw) ((((sjw) - 1) << BTR0_SJW_SHIFT) & \ + BTR0_SJW_MASK) + +#define BTR1_SET_TSEG1(tseg1) (((tseg1) - 1) & BTR1_TSEG1_MASK) +#define BTR1_SET_TSEG2(tseg2) ((((tseg2) - 1) << BTR1_TSEG2_SHIFT) & \ + BTR1_TSEG2_MASK) +#define BTR1_SET_SAM(sam) (((sam) & 1) << BTR1_SAM_SHIFT) + +static struct can_bittiming_const mscan_bittiming_const = { + .tseg1_min = 4, + .tseg1_max = 16, + .tseg2_min = 2, + .tseg2_max = 8, + .sjw_max = 4, + .brp_min = 1, + .brp_max = 64, + .brp_inc = 1, +}; + +struct mscan_state { + u8 mode; + u8 canrier; + u8 cantier; +}; + +#define TX_QUEUE_SIZE 3 + +struct tx_queue_entry { + struct list_head list; + u8 mask; + u8 id; +}; + +struct mscan_priv { + struct can_priv can; + long open_time; + unsigned long flags; + u8 shadow_statflg; + u8 shadow_canrier; + u8 cur_pri; + u8 tx_active; + + struct list_head tx_head; + struct tx_queue_entry tx_queue[TX_QUEUE_SIZE]; + struct napi_struct napi; + struct net_device *dev; +}; + +#define F_RX_PROGRESS 0 +#define F_TX_PROGRESS 1 +#define F_TX_WAIT_ALL 2 + +static enum can_state state_map[] = { + CAN_STATE_ACTIVE, + CAN_STATE_BUS_WARNING, + CAN_STATE_BUS_PASSIVE, + CAN_STATE_BUS_OFF +}; + +static int mscan_set_mode(struct net_device *dev, u8 mode) +{ + struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr; + struct mscan_priv *priv = netdev_priv(dev); + int ret = 0; + int i; + u8 canctl1; + + if (mode != MSCAN_NORMAL_MODE) { + + if (priv->tx_active) { + /* Abort transfers before going to sleep */ + out_8(®s->cantier, 0); + out_8(®s->cantarq, priv->tx_active); + out_8(®s->cantier, priv->tx_active); + } + + canctl1 = in_8(®s->canctl1); + if ((mode & MSCAN_SLPRQ) && (canctl1 & MSCAN_SLPAK) == 0) { + out_8(®s->canctl0, + in_8(®s->canctl0) | MSCAN_SLPRQ); + for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) { + if (in_8(®s->canctl1) & MSCAN_SLPAK) + break; + udelay(100); + } + if (i >= MSCAN_SET_MODE_RETRIES) + ret = -ENODEV; + } + if (!ret) + priv->can.state = CAN_STATE_SLEEPING; + + if (!ret && (mode & MSCAN_INITRQ) + && (canctl1 & MSCAN_INITAK) == 0) { + out_8(®s->canctl0, + in_8(®s->canctl0) | MSCAN_INITRQ); + for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) { + if (in_8(®s->canctl1) & MSCAN_INITAK) + break; + } + if (i >= MSCAN_SET_MODE_RETRIES) + ret = -ENODEV; + } + if (!ret) + priv->can.state = CAN_STATE_STOPPED; + + if (!ret && (mode & MSCAN_CSWAI)) + out_8(®s->canctl0, + in_8(®s->canctl0) | MSCAN_CSWAI); + + } else { + canctl1 = in_8(®s->canctl1); + if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) { + out_8(®s->canctl0, in_8(®s->canctl0) & + ~(MSCAN_SLPRQ | MSCAN_INITRQ)); + for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) { + canctl1 = in_8(®s->canctl1); + if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK))) + break; + } + if (i >= MSCAN_SET_MODE_RETRIES) + ret = -ENODEV; + else + priv->can.state = CAN_STATE_ACTIVE; + } + } + return ret; +} + +static int mscan_start(struct net_device *dev) +{ + struct mscan_priv *priv = netdev_priv(dev); + struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr; + u8 canrflg; + int err; + + out_8(®s->canrier, 0); + + INIT_LIST_HEAD(&priv->tx_head); + priv->cur_pri = 0; + priv->tx_active = 0; + priv->shadow_canrier = 0; + priv->flags = 0; + + err = mscan_set_mode(dev, MSCAN_NORMAL_MODE); + if (err) + return err; + + canrflg = in_8(®s->canrflg); + priv->shadow_statflg = canrflg & MSCAN_STAT_MSK; + priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg), + MSCAN_STATE_TX(canrflg))]; + out_8(®s->cantier, 0); + + /* Enable receive interrupts. */ + out_8(®s->canrier, MSCAN_OVRIE | MSCAN_RXFIE | MSCAN_CSCIE | + MSCAN_RSTATE1 | MSCAN_RSTATE0 | MSCAN_TSTATE1 | MSCAN_TSTATE0); + + return 0; +} + +static int mscan_start_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct can_frame *frame = (struct can_frame *)skb->data; + struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr; + struct mscan_priv *priv = netdev_priv(dev); + int i, rtr, buf_id; + u32 can_id; + + if (frame->can_dlc > 8) + return -EINVAL; + + out_8(®s->cantier, 0); + + i = ~priv->tx_active & MSCAN_TXE; + buf_id = ffs(i) - 1; + switch (hweight8(i)) { + case 0: + netif_stop_queue(dev); + dev_err(ND2D(dev), "BUG! Tx Ring full when queue awake!\n"); + return NETDEV_TX_BUSY; + case 1: + /* if buf_id < 3, then current frame will be send out of order, + since buffer with lower id have higher priority (hell..) */ + if (buf_id < 3) + priv->cur_pri++; + if (priv->cur_pri == 0xff) + set_bit(F_TX_WAIT_ALL, &priv->flags); + netif_stop_queue(dev); + case 2: + set_bit(F_TX_PROGRESS, &priv->flags); + } + out_8(®s->cantbsel, i); + + rtr = frame->can_id & CAN_RTR_FLAG; + + if (frame->can_id & CAN_EFF_FLAG) { + can_id = (frame->can_id & CAN_EFF_MASK) << 1; + if (rtr) + can_id |= 1; + out_be16(®s->tx.idr3_2, can_id); + + can_id >>= 16; + can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0) | (3 << 3); + } else { + can_id = (frame->can_id & CAN_SFF_MASK) << 5; + if (rtr) + can_id |= 1 << 4; + } + out_be16(®s->tx.idr1_0, can_id); + + if (!rtr) { + void __iomem *data = ®s->tx.dsr1_0; + u16 *payload = (u16 *) frame->data; + /*Its safe to write into dsr[dlc+1] */ + for (i = 0; i < (frame->can_dlc + 1) / 2; i++) { + out_be16(data, *payload++); + data += 2 + _MSCAN_RESERVED_DSR_SIZE; + } + } + + out_8(®s->tx.dlr, frame->can_dlc); + out_8(®s->tx.tbpr, priv->cur_pri); + + /* Start transmission. */ + out_8(®s->cantflg, 1 << buf_id); + + if (!test_bit(F_TX_PROGRESS, &priv->flags)) + dev->trans_start = jiffies; + + list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head); + + can_put_echo_skb(skb, dev, buf_id); + + /* Enable interrupt. */ + priv->tx_active |= 1 << buf_id; + out_8(®s->cantier, priv->tx_active); + + return NETDEV_TX_OK; +} + +static inline int check_set_state(struct net_device *dev, u8 canrflg) +{ + struct mscan_priv *priv = netdev_priv(dev); + enum can_state state; + int ret = 0; + + if (!(canrflg & MSCAN_CSCIF) || priv->can.state > CAN_STATE_BUS_OFF) + return 0; + + state = state_map[max(MSCAN_STATE_RX(canrflg), + MSCAN_STATE_TX(canrflg))]; + if (priv->can.state < state) + ret = 1; + if (state == CAN_STATE_BUS_OFF) + can_bus_off(dev); + priv->can.state = state; + return ret; +} + +static int mscan_rx_poll(struct napi_struct *napi, int quota) +{ + struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi); + struct net_device *dev = priv->dev; + struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr; + struct net_device_stats *stats = &dev->stats; + int npackets = 0; + int ret = 1; + struct sk_buff *skb; + struct can_frame *frame; + u32 can_id; + u8 canrflg; + int i; + + while (npackets < quota && ((canrflg = in_8(®s->canrflg)) & + (MSCAN_RXF | MSCAN_ERR_IF))) { + + skb = dev_alloc_skb(sizeof(struct can_frame)); + if (!skb) { + if (printk_ratelimit()) + dev_notice(ND2D(dev), "packet dropped\n"); + stats->rx_dropped++; + out_8(®s->canrflg, canrflg); + continue; + } + + frame = (struct can_frame *)skb_put(skb, sizeof(*frame)); + memset(frame, 0, sizeof(*frame)); + + if (canrflg & MSCAN_RXF) { + can_id = in_be16(®s->rx.idr1_0); + if (can_id & (1 << 3)) { + frame->can_id = CAN_EFF_FLAG; + can_id = ((can_id << 16) | + in_be16(®s->rx.idr3_2)); + can_id = ((can_id & 0xffe00000) | + ((can_id & 0x7ffff) << 2)) >> 2; + } else { + can_id >>= 4; + frame->can_id = 0; + } + + frame->can_id |= can_id >> 1; + if (can_id & 1) + frame->can_id |= CAN_RTR_FLAG; + frame->can_dlc = in_8(®s->rx.dlr) & 0xf; + + if (!(frame->can_id & CAN_RTR_FLAG)) { + void __iomem *data = ®s->rx.dsr1_0; + u16 *payload = (u16 *) frame->data; + for (i = 0; i < (frame->can_dlc + 1) / 2; i++) { + *payload++ = in_be16(data); + data += 2 + _MSCAN_RESERVED_DSR_SIZE; + } + } + + out_8(®s->canrflg, MSCAN_RXF); + dev->last_rx = jiffies; + stats->rx_packets++; + stats->rx_bytes += frame->can_dlc; + } else if (canrflg & MSCAN_ERR_IF) { + dev_dbg(ND2D(dev), "error interrupt (canrflg=%#x)\n", + canrflg); + frame->can_id = CAN_ERR_FLAG; + + if (canrflg & MSCAN_OVRIF) { + frame->can_id |= CAN_ERR_CRTL; + frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; + stats->rx_over_errors++; + } else + frame->data[1] = 0; + + if (check_set_state(dev, canrflg)) { + frame->can_id |= CAN_ERR_CRTL; + switch (priv->can.state) { + case CAN_STATE_BUS_WARNING: + if ((priv->shadow_statflg & + MSCAN_RSTAT_MSK) < + (canrflg & MSCAN_RSTAT_MSK)) + frame->data[1] |= + CAN_ERR_CRTL_RX_WARNING; + + if ((priv->shadow_statflg & + MSCAN_TSTAT_MSK) < + (canrflg & MSCAN_TSTAT_MSK)) + frame->data[1] |= + CAN_ERR_CRTL_TX_WARNING; + break; + case CAN_STATE_BUS_PASSIVE: + frame->data[1] |= + CAN_ERR_CRTL_RX_PASSIVE; + break; + case CAN_STATE_BUS_OFF: + frame->can_id |= CAN_ERR_BUSOFF; + frame->can_id &= ~CAN_ERR_CRTL; + break; + default: + break; + } + } + priv->shadow_statflg = canrflg & MSCAN_STAT_MSK; + frame->can_dlc = CAN_ERR_DLC; + out_8(®s->canrflg, MSCAN_ERR_IF); + } + + npackets++; + skb->dev = dev; + skb->protocol = __constant_htons(ETH_P_CAN); + skb->ip_summed = CHECKSUM_UNNECESSARY; + netif_receive_skb(skb); + } + + if (!(in_8(®s->canrflg) & (MSCAN_RXF | MSCAN_ERR_IF))) { + netif_rx_complete(dev, &priv->napi); + clear_bit(F_RX_PROGRESS, &priv->flags); + if (priv->can.state < CAN_STATE_BUS_OFF) + out_8(®s->canrier, priv->shadow_canrier); + ret = 0; + } + return ret; +} + +static irqreturn_t mscan_isr(int irq, void *dev_id) +{ + struct net_device *dev = (struct net_device *)dev_id; + struct mscan_priv *priv = netdev_priv(dev); + struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr; + struct net_device_stats *stats = &dev->stats; + u8 cantier, cantflg, canrflg; + irqreturn_t ret = IRQ_NONE; + + cantier = in_8(®s->cantier) & MSCAN_TXE; + cantflg = in_8(®s->cantflg) & cantier; + + if (cantier && cantflg) { + + struct list_head *tmp, *pos; + + list_for_each_safe(pos, tmp, &priv->tx_head) { + struct tx_queue_entry *entry = + list_entry(pos, struct tx_queue_entry, list); + u8 mask = entry->mask; + + if (!(cantflg & mask)) + continue; + + out_8(®s->cantbsel, mask); + stats->tx_bytes += in_8(®s->tx.dlr); + stats->tx_packets++; + can_get_echo_skb(dev, entry->id); + priv->tx_active &= ~mask; + list_del(pos); + } + + if (list_empty(&priv->tx_head)) { + clear_bit(F_TX_WAIT_ALL, &priv->flags); + clear_bit(F_TX_PROGRESS, &priv->flags); + priv->cur_pri = 0; + } else + dev->trans_start = jiffies; + + if (!test_bit(F_TX_WAIT_ALL, &priv->flags)) + netif_wake_queue(dev); + + out_8(®s->cantier, priv->tx_active); + ret = IRQ_HANDLED; + } + + canrflg = in_8(®s->canrflg); + if ((canrflg & ~MSCAN_STAT_MSK) && + !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) { + if (canrflg & ~MSCAN_STAT_MSK) { + priv->shadow_canrier = in_8(®s->canrier); + out_8(®s->canrier, 0); + netif_rx_schedule(dev, &priv->napi); + ret = IRQ_HANDLED; + } else + clear_bit(F_RX_PROGRESS, &priv->flags); + } + return ret; +} + +static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode) +{ + + struct mscan_priv *priv = netdev_priv(dev); + int ret = 0; + + if (!priv->open_time) + return -EINVAL; + + switch (mode) { + case CAN_MODE_SLEEP: + case CAN_MODE_STOP: + netif_stop_queue(dev); + mscan_set_mode(dev, + (mode == + CAN_MODE_STOP) ? MSCAN_INIT_MODE : + MSCAN_SLEEP_MODE); + break; + case CAN_MODE_START: + if (priv->can.state <= CAN_STATE_BUS_OFF) + mscan_set_mode(dev, MSCAN_INIT_MODE); + ret = mscan_start(dev); + if (ret) + break; + if (netif_queue_stopped(dev)) + netif_wake_queue(dev); + break; + + default: + ret = -EOPNOTSUPP; + break; + } + return ret; +} + +static int mscan_do_set_bittiming(struct net_device *dev) +{ + struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr; + struct mscan_priv *priv = netdev_priv(dev); + struct can_bittiming *bt = &priv->can.bittiming; + u8 btr0, btr1; + + btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw); + btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) | + BTR1_SET_TSEG2(bt->phase_seg2) | + BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)); + + dev_info(ND2D(dev), "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); + + out_8(®s->canbtr0, btr0); + out_8(®s->canbtr1, btr1); + + return 0; +} + +static int mscan_open(struct net_device *dev) +{ + int ret; + struct mscan_priv *priv = netdev_priv(dev); + struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr; + + /* determine and set bittime */ + ret = can_set_bittiming(dev); + if (ret) + return ret; + + napi_enable(&priv->napi); + ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev); + + if (ret < 0) { + napi_disable(&priv->napi); + printk(KERN_ERR "%s - failed to attach interrupt\n", + dev->name); + return ret; + } + + priv->open_time = jiffies; + + out_8(®s->canctl1, in_8(®s->canctl1) & ~MSCAN_LISTEN); + + ret = mscan_start(dev); + if (ret) + return ret; + + netif_start_queue(dev); + + return 0; +} + +static int mscan_close(struct net_device *dev) +{ + struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr; + struct mscan_priv *priv = netdev_priv(dev); + + napi_disable(&priv->napi); + + out_8(®s->cantier, 0); + out_8(®s->canrier, 0); + free_irq(dev->irq, dev); + mscan_set_mode(dev, MSCAN_INIT_MODE); + can_close_cleanup(dev); + netif_stop_queue(dev); + priv->open_time = 0; + + return 0; +} + +int register_mscandev(struct net_device *dev, int clock_src) +{ + struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr; + u8 ctl1; + + ctl1 = in_8(®s->canctl1); + if (clock_src) + ctl1 |= MSCAN_CLKSRC; + else + ctl1 &= ~MSCAN_CLKSRC; + + ctl1 |= MSCAN_CANE; + out_8(®s->canctl1, ctl1); + udelay(100); + + /* acceptance mask/acceptance code (accept everything) */ + out_be16(®s->canidar1_0, 0); + out_be16(®s->canidar3_2, 0); + out_be16(®s->canidar5_4, 0); + out_be16(®s->canidar7_6, 0); + + out_be16(®s->canidmr1_0, 0xffff); + out_be16(®s->canidmr3_2, 0xffff); + out_be16(®s->canidmr5_4, 0xffff); + out_be16(®s->canidmr7_6, 0xffff); + /* Two 32 bit Acceptance Filters */ + out_8(®s->canidac, MSCAN_AF_32BIT); + + mscan_set_mode(dev, MSCAN_INIT_MODE); + + return register_candev(dev); +} +EXPORT_SYMBOL_GPL(register_mscandev); + +void unregister_mscandev(struct net_device *dev) +{ + struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr; + mscan_set_mode(dev, MSCAN_INIT_MODE); + out_8(®s->canctl1, in_8(®s->canctl1) & ~MSCAN_CANE); + unregister_candev(dev); +} +EXPORT_SYMBOL_GPL(unregister_mscandev); + +struct net_device *alloc_mscandev(void) +{ + struct net_device *dev; + struct mscan_priv *priv; + int i; + + dev = alloc_candev(sizeof(struct mscan_priv)); + if (!dev) + return NULL; + priv = netdev_priv(dev); + + dev->open = mscan_open; + dev->stop = mscan_close; + dev->hard_start_xmit = mscan_start_xmit; + + dev->flags |= IFF_ECHO; /* we support local echo */ + + priv->dev = dev; + netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8); + + priv->can.bittiming_const = &mscan_bittiming_const; + priv->can.do_set_bittiming = mscan_do_set_bittiming; + priv->can.do_set_mode = mscan_do_set_mode; + + for (i = 0; i < TX_QUEUE_SIZE; i++) { + priv->tx_queue[i].id = i; + priv->tx_queue[i].mask = 1 << i; + } + + return dev; +} +EXPORT_SYMBOL_GPL(alloc_mscandev); + +MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips"); |