| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Andreas Larsson | 7145 | 98.96% | 1 | 9.09% |
| Kees Cook | 44 | 0.61% | 2 | 18.18% |
| Laurent Navet | 8 | 0.11% | 1 | 9.09% |
| Allen Pais | 6 | 0.08% | 1 | 9.09% |
| Oliver Hartkopp | 5 | 0.07% | 1 | 9.09% |
| Marc Kleine-Budde | 5 | 0.07% | 1 | 9.09% |
| Thomas Gleixner | 2 | 0.03% | 1 | 9.09% |
| Joe Perches | 2 | 0.03% | 1 | 9.09% |
| Jingoo Han | 2 | 0.03% | 1 | 9.09% |
| Fabian Frederick | 1 | 0.01% | 1 | 9.09% |
| Total | 7220 | 11 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * Socket CAN driver for Aeroflex Gaisler GRCAN and GRHCAN. * * 2012 (c) Aeroflex Gaisler AB * * This driver supports GRCAN and GRHCAN CAN controllers available in the GRLIB * VHDL IP core library. * * Full documentation of the GRCAN core can be found here: * http://www.gaisler.com/products/grlib/grip.pdf * * See "Documentation/devicetree/bindings/net/can/grcan.txt" for information on * open firmware properties. * * See "Documentation/ABI/testing/sysfs-class-net-grcan" for information on the * sysfs interface. * * See "Documentation/admin-guide/kernel-parameters.rst" for information on the module * parameters. * * Contributors: Andreas Larsson <andreas@gaisler.com> */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/netdevice.h> #include <linux/delay.h> #include <linux/io.h> #include <linux/can/dev.h> #include <linux/spinlock.h> #include <linux/of_platform.h> #include <linux/of_irq.h> #include <linux/dma-mapping.h> #define DRV_NAME "grcan" #define GRCAN_NAPI_WEIGHT 32 #define GRCAN_RESERVE_SIZE(slot1, slot2) (((slot2) - (slot1)) / 4 - 1) struct grcan_registers { u32 conf; /* 0x00 */ u32 stat; /* 0x04 */ u32 ctrl; /* 0x08 */ u32 __reserved1[GRCAN_RESERVE_SIZE(0x08, 0x18)]; u32 smask; /* 0x18 - CanMASK */ u32 scode; /* 0x1c - CanCODE */ u32 __reserved2[GRCAN_RESERVE_SIZE(0x1c, 0x100)]; u32 pimsr; /* 0x100 */ u32 pimr; /* 0x104 */ u32 pisr; /* 0x108 */ u32 pir; /* 0x10C */ u32 imr; /* 0x110 */ u32 picr; /* 0x114 */ u32 __reserved3[GRCAN_RESERVE_SIZE(0x114, 0x200)]; u32 txctrl; /* 0x200 */ u32 txaddr; /* 0x204 */ u32 txsize; /* 0x208 */ u32 txwr; /* 0x20C */ u32 txrd; /* 0x210 */ u32 txirq; /* 0x214 */ u32 __reserved4[GRCAN_RESERVE_SIZE(0x214, 0x300)]; u32 rxctrl; /* 0x300 */ u32 rxaddr; /* 0x304 */ u32 rxsize; /* 0x308 */ u32 rxwr; /* 0x30C */ u32 rxrd; /* 0x310 */ u32 rxirq; /* 0x314 */ u32 rxmask; /* 0x318 */ u32 rxcode; /* 0x31C */ }; #define GRCAN_CONF_ABORT 0x00000001 #define GRCAN_CONF_ENABLE0 0x00000002 #define GRCAN_CONF_ENABLE1 0x00000004 #define GRCAN_CONF_SELECT 0x00000008 #define GRCAN_CONF_SILENT 0x00000010 #define GRCAN_CONF_SAM 0x00000020 /* Available in some hardware */ #define GRCAN_CONF_BPR 0x00000300 /* Note: not BRP */ #define GRCAN_CONF_RSJ 0x00007000 #define GRCAN_CONF_PS1 0x00f00000 #define GRCAN_CONF_PS2 0x000f0000 #define GRCAN_CONF_SCALER 0xff000000 #define GRCAN_CONF_OPERATION \ (GRCAN_CONF_ABORT | GRCAN_CONF_ENABLE0 | GRCAN_CONF_ENABLE1 \ | GRCAN_CONF_SELECT | GRCAN_CONF_SILENT | GRCAN_CONF_SAM) #define GRCAN_CONF_TIMING \ (GRCAN_CONF_BPR | GRCAN_CONF_RSJ | GRCAN_CONF_PS1 \ | GRCAN_CONF_PS2 | GRCAN_CONF_SCALER) #define GRCAN_CONF_RSJ_MIN 1 #define GRCAN_CONF_RSJ_MAX 4 #define GRCAN_CONF_PS1_MIN 1 #define GRCAN_CONF_PS1_MAX 15 #define GRCAN_CONF_PS2_MIN 2 #define GRCAN_CONF_PS2_MAX 8 #define GRCAN_CONF_SCALER_MIN 0 #define GRCAN_CONF_SCALER_MAX 255 #define GRCAN_CONF_SCALER_INC 1 #define GRCAN_CONF_BPR_BIT 8 #define GRCAN_CONF_RSJ_BIT 12 #define GRCAN_CONF_PS1_BIT 20 #define GRCAN_CONF_PS2_BIT 16 #define GRCAN_CONF_SCALER_BIT 24 #define GRCAN_STAT_PASS 0x000001 #define GRCAN_STAT_OFF 0x000002 #define GRCAN_STAT_OR 0x000004 #define GRCAN_STAT_AHBERR 0x000008 #define GRCAN_STAT_ACTIVE 0x000010 #define GRCAN_STAT_RXERRCNT 0x00ff00 #define GRCAN_STAT_TXERRCNT 0xff0000 #define GRCAN_STAT_ERRCTR_RELATED (GRCAN_STAT_PASS | GRCAN_STAT_OFF) #define GRCAN_STAT_RXERRCNT_BIT 8 #define GRCAN_STAT_TXERRCNT_BIT 16 #define GRCAN_STAT_ERRCNT_WARNING_LIMIT 96 #define GRCAN_STAT_ERRCNT_PASSIVE_LIMIT 127 #define GRCAN_CTRL_RESET 0x2 #define GRCAN_CTRL_ENABLE 0x1 #define GRCAN_TXCTRL_ENABLE 0x1 #define GRCAN_TXCTRL_ONGOING 0x2 #define GRCAN_TXCTRL_SINGLE 0x4 #define GRCAN_RXCTRL_ENABLE 0x1 #define GRCAN_RXCTRL_ONGOING 0x2 /* Relative offset of IRQ sources to AMBA Plug&Play */ #define GRCAN_IRQIX_IRQ 0 #define GRCAN_IRQIX_TXSYNC 1 #define GRCAN_IRQIX_RXSYNC 2 #define GRCAN_IRQ_PASS 0x00001 #define GRCAN_IRQ_OFF 0x00002 #define GRCAN_IRQ_OR 0x00004 #define GRCAN_IRQ_RXAHBERR 0x00008 #define GRCAN_IRQ_TXAHBERR 0x00010 #define GRCAN_IRQ_RXIRQ 0x00020 #define GRCAN_IRQ_TXIRQ 0x00040 #define GRCAN_IRQ_RXFULL 0x00080 #define GRCAN_IRQ_TXEMPTY 0x00100 #define GRCAN_IRQ_RX 0x00200 #define GRCAN_IRQ_TX 0x00400 #define GRCAN_IRQ_RXSYNC 0x00800 #define GRCAN_IRQ_TXSYNC 0x01000 #define GRCAN_IRQ_RXERRCTR 0x02000 #define GRCAN_IRQ_TXERRCTR 0x04000 #define GRCAN_IRQ_RXMISS 0x08000 #define GRCAN_IRQ_TXLOSS 0x10000 #define GRCAN_IRQ_NONE 0 #define GRCAN_IRQ_ALL \ (GRCAN_IRQ_PASS | GRCAN_IRQ_OFF | GRCAN_IRQ_OR \ | GRCAN_IRQ_RXAHBERR | GRCAN_IRQ_TXAHBERR \ | GRCAN_IRQ_RXIRQ | GRCAN_IRQ_TXIRQ \ | GRCAN_IRQ_RXFULL | GRCAN_IRQ_TXEMPTY \ | GRCAN_IRQ_RX | GRCAN_IRQ_TX | GRCAN_IRQ_RXSYNC \ | GRCAN_IRQ_TXSYNC | GRCAN_IRQ_RXERRCTR \ | GRCAN_IRQ_TXERRCTR | GRCAN_IRQ_RXMISS \ | GRCAN_IRQ_TXLOSS) #define GRCAN_IRQ_ERRCTR_RELATED (GRCAN_IRQ_RXERRCTR | GRCAN_IRQ_TXERRCTR \ | GRCAN_IRQ_PASS | GRCAN_IRQ_OFF) #define GRCAN_IRQ_ERRORS (GRCAN_IRQ_ERRCTR_RELATED | GRCAN_IRQ_OR \ | GRCAN_IRQ_TXAHBERR | GRCAN_IRQ_RXAHBERR \ | GRCAN_IRQ_TXLOSS) #define GRCAN_IRQ_DEFAULT (GRCAN_IRQ_RX | GRCAN_IRQ_TX | GRCAN_IRQ_ERRORS) #define GRCAN_MSG_SIZE 16 #define GRCAN_MSG_IDE 0x80000000 #define GRCAN_MSG_RTR 0x40000000 #define GRCAN_MSG_BID 0x1ffc0000 #define GRCAN_MSG_EID 0x1fffffff #define GRCAN_MSG_IDE_BIT 31 #define GRCAN_MSG_RTR_BIT 30 #define GRCAN_MSG_BID_BIT 18 #define GRCAN_MSG_EID_BIT 0 #define GRCAN_MSG_DLC 0xf0000000 #define GRCAN_MSG_TXERRC 0x00ff0000 #define GRCAN_MSG_RXERRC 0x0000ff00 #define GRCAN_MSG_DLC_BIT 28 #define GRCAN_MSG_TXERRC_BIT 16 #define GRCAN_MSG_RXERRC_BIT 8 #define GRCAN_MSG_AHBERR 0x00000008 #define GRCAN_MSG_OR 0x00000004 #define GRCAN_MSG_OFF 0x00000002 #define GRCAN_MSG_PASS 0x00000001 #define GRCAN_MSG_DATA_SLOT_INDEX(i) (2 + (i) / 4) #define GRCAN_MSG_DATA_SHIFT(i) ((3 - (i) % 4) * 8) #define GRCAN_BUFFER_ALIGNMENT 1024 #define GRCAN_DEFAULT_BUFFER_SIZE 1024 #define GRCAN_VALID_TR_SIZE_MASK 0x001fffc0 #define GRCAN_INVALID_BUFFER_SIZE(s) \ ((s) == 0 || ((s) & ~GRCAN_VALID_TR_SIZE_MASK)) #if GRCAN_INVALID_BUFFER_SIZE(GRCAN_DEFAULT_BUFFER_SIZE) #error "Invalid default buffer size" #endif struct grcan_dma_buffer { size_t size; void *buf; dma_addr_t handle; }; struct grcan_dma { size_t base_size; void *base_buf; dma_addr_t base_handle; struct grcan_dma_buffer tx; struct grcan_dma_buffer rx; }; /* GRCAN configuration parameters */ struct grcan_device_config { unsigned short enable0; unsigned short enable1; unsigned short select; unsigned int txsize; unsigned int rxsize; }; #define GRCAN_DEFAULT_DEVICE_CONFIG { \ .enable0 = 0, \ .enable1 = 0, \ .select = 0, \ .txsize = GRCAN_DEFAULT_BUFFER_SIZE, \ .rxsize = GRCAN_DEFAULT_BUFFER_SIZE, \ } #define GRCAN_TXBUG_SAFE_GRLIB_VERSION 0x4100 #define GRLIB_VERSION_MASK 0xffff /* GRCAN private data structure */ struct grcan_priv { struct can_priv can; /* must be the first member */ struct net_device *dev; struct napi_struct napi; struct grcan_registers __iomem *regs; /* ioremap'ed registers */ struct grcan_device_config config; struct grcan_dma dma; struct sk_buff **echo_skb; /* We allocate this on our own */ u8 *txdlc; /* Length of queued frames */ /* The echo skb pointer, pointing into echo_skb and indicating which * frames can be echoed back. See the "Notes on the tx cyclic buffer * handling"-comment for grcan_start_xmit for more details. */ u32 eskbp; /* Lock for controlling changes to the netif tx queue state, accesses to * the echo_skb pointer eskbp and for making sure that a running reset * and/or a close of the interface is done without interference from * other parts of the code. * * The echo_skb pointer, eskbp, should only be accessed under this lock * as it can be changed in several places and together with decisions on * whether to wake up the tx queue. * * The tx queue must never be woken up if there is a running reset or * close in progress. * * A running reset (see below on need_txbug_workaround) should never be * done if the interface is closing down and several running resets * should never be scheduled simultaneously. */ spinlock_t lock; /* Whether a workaround is needed due to a bug in older hardware. In * this case, the driver both tries to prevent the bug from being * triggered and recovers, if the bug nevertheless happens, by doing a * running reset. A running reset, resets the device and continues from * where it were without being noticeable from outside the driver (apart * from slight delays). */ bool need_txbug_workaround; /* To trigger initization of running reset and to trigger running reset * respectively in the case of a hanged device due to a txbug. */ struct timer_list hang_timer; struct timer_list rr_timer; /* To avoid waking up the netif queue and restarting timers * when a reset is scheduled or when closing of the device is * undergoing */ bool resetting; bool closing; }; /* Wait time for a short wait for ongoing to clear */ #define GRCAN_SHORTWAIT_USECS 10 /* Limit on the number of transmitted bits of an eff frame according to the CAN * specification: 1 bit start of frame, 32 bits arbitration field, 6 bits * control field, 8 bytes data field, 16 bits crc field, 2 bits ACK field and 7 * bits end of frame */ #define GRCAN_EFF_FRAME_MAX_BITS (1+32+6+8*8+16+2+7) #if defined(__BIG_ENDIAN) static inline u32 grcan_read_reg(u32 __iomem *reg) { return ioread32be(reg); } static inline void grcan_write_reg(u32 __iomem *reg, u32 val) { iowrite32be(val, reg); } #else static inline u32 grcan_read_reg(u32 __iomem *reg) { return ioread32(reg); } static inline void grcan_write_reg(u32 __iomem *reg, u32 val) { iowrite32(val, reg); } #endif static inline void grcan_clear_bits(u32 __iomem *reg, u32 mask) { grcan_write_reg(reg, grcan_read_reg(reg) & ~mask); } static inline void grcan_set_bits(u32 __iomem *reg, u32 mask) { grcan_write_reg(reg, grcan_read_reg(reg) | mask); } static inline u32 grcan_read_bits(u32 __iomem *reg, u32 mask) { return grcan_read_reg(reg) & mask; } static inline void grcan_write_bits(u32 __iomem *reg, u32 value, u32 mask) { u32 old = grcan_read_reg(reg); grcan_write_reg(reg, (old & ~mask) | (value & mask)); } /* a and b should both be in [0,size] and a == b == size should not hold */ static inline u32 grcan_ring_add(u32 a, u32 b, u32 size) { u32 sum = a + b; if (sum < size) return sum; else return sum - size; } /* a and b should both be in [0,size) */ static inline u32 grcan_ring_sub(u32 a, u32 b, u32 size) { return grcan_ring_add(a, size - b, size); } /* Available slots for new transmissions */ static inline u32 grcan_txspace(size_t txsize, u32 txwr, u32 eskbp) { u32 slots = txsize / GRCAN_MSG_SIZE - 1; u32 used = grcan_ring_sub(txwr, eskbp, txsize) / GRCAN_MSG_SIZE; return slots - used; } /* Configuration parameters that can be set via module parameters */ static struct grcan_device_config grcan_module_config = GRCAN_DEFAULT_DEVICE_CONFIG; static const struct can_bittiming_const grcan_bittiming_const = { .name = DRV_NAME, .tseg1_min = GRCAN_CONF_PS1_MIN + 1, .tseg1_max = GRCAN_CONF_PS1_MAX + 1, .tseg2_min = GRCAN_CONF_PS2_MIN, .tseg2_max = GRCAN_CONF_PS2_MAX, .sjw_max = GRCAN_CONF_RSJ_MAX, .brp_min = GRCAN_CONF_SCALER_MIN + 1, .brp_max = GRCAN_CONF_SCALER_MAX + 1, .brp_inc = GRCAN_CONF_SCALER_INC, }; static int grcan_set_bittiming(struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; struct can_bittiming *bt = &priv->can.bittiming; u32 timing = 0; int bpr, rsj, ps1, ps2, scaler; /* Should never happen - function will not be called when * device is up */ if (grcan_read_bits(®s->ctrl, GRCAN_CTRL_ENABLE)) return -EBUSY; bpr = 0; /* Note bpr and brp are different concepts */ rsj = bt->sjw; ps1 = (bt->prop_seg + bt->phase_seg1) - 1; /* tseg1 - 1 */ ps2 = bt->phase_seg2; scaler = (bt->brp - 1); netdev_dbg(dev, "Request for BPR=%d, RSJ=%d, PS1=%d, PS2=%d, SCALER=%d", bpr, rsj, ps1, ps2, scaler); if (!(ps1 > ps2)) { netdev_err(dev, "PS1 > PS2 must hold: PS1=%d, PS2=%d\n", ps1, ps2); return -EINVAL; } if (!(ps2 >= rsj)) { netdev_err(dev, "PS2 >= RSJ must hold: PS2=%d, RSJ=%d\n", ps2, rsj); return -EINVAL; } timing |= (bpr << GRCAN_CONF_BPR_BIT) & GRCAN_CONF_BPR; timing |= (rsj << GRCAN_CONF_RSJ_BIT) & GRCAN_CONF_RSJ; timing |= (ps1 << GRCAN_CONF_PS1_BIT) & GRCAN_CONF_PS1; timing |= (ps2 << GRCAN_CONF_PS2_BIT) & GRCAN_CONF_PS2; timing |= (scaler << GRCAN_CONF_SCALER_BIT) & GRCAN_CONF_SCALER; netdev_info(dev, "setting timing=0x%x\n", timing); grcan_write_bits(®s->conf, timing, GRCAN_CONF_TIMING); return 0; } static int grcan_get_berr_counter(const struct net_device *dev, struct can_berr_counter *bec) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; u32 status = grcan_read_reg(®s->stat); bec->txerr = (status & GRCAN_STAT_TXERRCNT) >> GRCAN_STAT_TXERRCNT_BIT; bec->rxerr = (status & GRCAN_STAT_RXERRCNT) >> GRCAN_STAT_RXERRCNT_BIT; return 0; } static int grcan_poll(struct napi_struct *napi, int budget); /* Reset device, but keep configuration information */ static void grcan_reset(struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; u32 config = grcan_read_reg(®s->conf); grcan_set_bits(®s->ctrl, GRCAN_CTRL_RESET); grcan_write_reg(®s->conf, config); priv->eskbp = grcan_read_reg(®s->txrd); priv->can.state = CAN_STATE_STOPPED; /* Turn off hardware filtering - regs->rxcode set to 0 by reset */ grcan_write_reg(®s->rxmask, 0); } /* stop device without changing any configurations */ static void grcan_stop_hardware(struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; grcan_write_reg(®s->imr, GRCAN_IRQ_NONE); grcan_clear_bits(®s->txctrl, GRCAN_TXCTRL_ENABLE); grcan_clear_bits(®s->rxctrl, GRCAN_RXCTRL_ENABLE); grcan_clear_bits(®s->ctrl, GRCAN_CTRL_ENABLE); } /* Let priv->eskbp catch up to regs->txrd and echo back the skbs if echo * is true and free them otherwise. * * If budget is >= 0, stop after handling at most budget skbs. Otherwise, * continue until priv->eskbp catches up to regs->txrd. * * priv->lock *must* be held when calling this function */ static int catch_up_echo_skb(struct net_device *dev, int budget, bool echo) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; struct grcan_dma *dma = &priv->dma; struct net_device_stats *stats = &dev->stats; int i, work_done; /* Updates to priv->eskbp and wake-ups of the queue needs to * be atomic towards the reads of priv->eskbp and shut-downs * of the queue in grcan_start_xmit. */ u32 txrd = grcan_read_reg(®s->txrd); for (work_done = 0; work_done < budget || budget < 0; work_done++) { if (priv->eskbp == txrd) break; i = priv->eskbp / GRCAN_MSG_SIZE; if (echo) { /* Normal echo of messages */ stats->tx_packets++; stats->tx_bytes += priv->txdlc[i]; priv->txdlc[i] = 0; can_get_echo_skb(dev, i); } else { /* For cleanup of untransmitted messages */ can_free_echo_skb(dev, i); } priv->eskbp = grcan_ring_add(priv->eskbp, GRCAN_MSG_SIZE, dma->tx.size); txrd = grcan_read_reg(®s->txrd); } return work_done; } static void grcan_lost_one_shot_frame(struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; struct grcan_dma *dma = &priv->dma; u32 txrd; unsigned long flags; spin_lock_irqsave(&priv->lock, flags); catch_up_echo_skb(dev, -1, true); if (unlikely(grcan_read_bits(®s->txctrl, GRCAN_TXCTRL_ENABLE))) { /* Should never happen */ netdev_err(dev, "TXCTRL enabled at TXLOSS in one shot mode\n"); } else { /* By the time an GRCAN_IRQ_TXLOSS is generated in * one-shot mode there is no problem in writing * to TXRD even in versions of the hardware in * which GRCAN_TXCTRL_ONGOING is not cleared properly * in one-shot mode. */ /* Skip message and discard echo-skb */ txrd = grcan_read_reg(®s->txrd); txrd = grcan_ring_add(txrd, GRCAN_MSG_SIZE, dma->tx.size); grcan_write_reg(®s->txrd, txrd); catch_up_echo_skb(dev, -1, false); if (!priv->resetting && !priv->closing && !(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)) { netif_wake_queue(dev); grcan_set_bits(®s->txctrl, GRCAN_TXCTRL_ENABLE); } } spin_unlock_irqrestore(&priv->lock, flags); } static void grcan_err(struct net_device *dev, u32 sources, u32 status) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; struct grcan_dma *dma = &priv->dma; struct net_device_stats *stats = &dev->stats; struct can_frame cf; /* Zero potential error_frame */ memset(&cf, 0, sizeof(cf)); /* Message lost interrupt. This might be due to arbitration error, but * is also triggered when there is no one else on the can bus or when * there is a problem with the hardware interface or the bus itself. As * arbitration errors can not be singled out, no error frames are * generated reporting this event as an arbitration error. */ if (sources & GRCAN_IRQ_TXLOSS) { /* Take care of failed one-shot transmit */ if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT) grcan_lost_one_shot_frame(dev); /* Stop printing as soon as error passive or bus off is in * effect to limit the amount of txloss debug printouts. */ if (!(status & GRCAN_STAT_ERRCTR_RELATED)) { netdev_dbg(dev, "tx message lost\n"); stats->tx_errors++; } } /* Conditions dealing with the error counters. There is no interrupt for * error warning, but there are interrupts for increases of the error * counters. */ if ((sources & GRCAN_IRQ_ERRCTR_RELATED) || (status & GRCAN_STAT_ERRCTR_RELATED)) { enum can_state state = priv->can.state; enum can_state oldstate = state; u32 txerr = (status & GRCAN_STAT_TXERRCNT) >> GRCAN_STAT_TXERRCNT_BIT; u32 rxerr = (status & GRCAN_STAT_RXERRCNT) >> GRCAN_STAT_RXERRCNT_BIT; /* Figure out current state */ if (status & GRCAN_STAT_OFF) { state = CAN_STATE_BUS_OFF; } else if (status & GRCAN_STAT_PASS) { state = CAN_STATE_ERROR_PASSIVE; } else if (txerr >= GRCAN_STAT_ERRCNT_WARNING_LIMIT || rxerr >= GRCAN_STAT_ERRCNT_WARNING_LIMIT) { state = CAN_STATE_ERROR_WARNING; } else { state = CAN_STATE_ERROR_ACTIVE; } /* Handle and report state changes */ if (state != oldstate) { switch (state) { case CAN_STATE_BUS_OFF: netdev_dbg(dev, "bus-off\n"); netif_carrier_off(dev); priv->can.can_stats.bus_off++; /* Prevent the hardware from recovering from bus * off on its own if restart is disabled. */ if (!priv->can.restart_ms) grcan_stop_hardware(dev); cf.can_id |= CAN_ERR_BUSOFF; break; case CAN_STATE_ERROR_PASSIVE: netdev_dbg(dev, "Error passive condition\n"); priv->can.can_stats.error_passive++; cf.can_id |= CAN_ERR_CRTL; if (txerr >= GRCAN_STAT_ERRCNT_PASSIVE_LIMIT) cf.data[1] |= CAN_ERR_CRTL_TX_PASSIVE; if (rxerr >= GRCAN_STAT_ERRCNT_PASSIVE_LIMIT) cf.data[1] |= CAN_ERR_CRTL_RX_PASSIVE; break; case CAN_STATE_ERROR_WARNING: netdev_dbg(dev, "Error warning condition\n"); priv->can.can_stats.error_warning++; cf.can_id |= CAN_ERR_CRTL; if (txerr >= GRCAN_STAT_ERRCNT_WARNING_LIMIT) cf.data[1] |= CAN_ERR_CRTL_TX_WARNING; if (rxerr >= GRCAN_STAT_ERRCNT_WARNING_LIMIT) cf.data[1] |= CAN_ERR_CRTL_RX_WARNING; break; case CAN_STATE_ERROR_ACTIVE: netdev_dbg(dev, "Error active condition\n"); cf.can_id |= CAN_ERR_CRTL; break; default: /* There are no others at this point */ break; } cf.data[6] = txerr; cf.data[7] = rxerr; priv->can.state = state; } /* Report automatic restarts */ if (priv->can.restart_ms && oldstate == CAN_STATE_BUS_OFF) { unsigned long flags; cf.can_id |= CAN_ERR_RESTARTED; netdev_dbg(dev, "restarted\n"); priv->can.can_stats.restarts++; netif_carrier_on(dev); spin_lock_irqsave(&priv->lock, flags); if (!priv->resetting && !priv->closing) { u32 txwr = grcan_read_reg(®s->txwr); if (grcan_txspace(dma->tx.size, txwr, priv->eskbp)) netif_wake_queue(dev); } spin_unlock_irqrestore(&priv->lock, flags); } } /* Data overrun interrupt */ if ((sources & GRCAN_IRQ_OR) || (status & GRCAN_STAT_OR)) { netdev_dbg(dev, "got data overrun interrupt\n"); stats->rx_over_errors++; stats->rx_errors++; cf.can_id |= CAN_ERR_CRTL; cf.data[1] |= CAN_ERR_CRTL_RX_OVERFLOW; } /* AHB bus error interrupts (not CAN bus errors) - shut down the * device. */ if (sources & (GRCAN_IRQ_TXAHBERR | GRCAN_IRQ_RXAHBERR) || (status & GRCAN_STAT_AHBERR)) { char *txrx = ""; unsigned long flags; if (sources & GRCAN_IRQ_TXAHBERR) { txrx = "on tx "; stats->tx_errors++; } else if (sources & GRCAN_IRQ_RXAHBERR) { txrx = "on rx "; stats->rx_errors++; } netdev_err(dev, "Fatal AHB buss error %s- halting device\n", txrx); spin_lock_irqsave(&priv->lock, flags); /* Prevent anything to be enabled again and halt device */ priv->closing = true; netif_stop_queue(dev); grcan_stop_hardware(dev); priv->can.state = CAN_STATE_STOPPED; spin_unlock_irqrestore(&priv->lock, flags); } /* Pass on error frame if something to report, * i.e. id contains some information */ if (cf.can_id) { struct can_frame *skb_cf; struct sk_buff *skb = alloc_can_err_skb(dev, &skb_cf); if (skb == NULL) { netdev_dbg(dev, "could not allocate error frame\n"); return; } skb_cf->can_id |= cf.can_id; memcpy(skb_cf->data, cf.data, sizeof(cf.data)); netif_rx(skb); } } static irqreturn_t grcan_interrupt(int irq, void *dev_id) { struct net_device *dev = dev_id; struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; u32 sources, status; /* Find out the source */ sources = grcan_read_reg(®s->pimsr); if (!sources) return IRQ_NONE; grcan_write_reg(®s->picr, sources); status = grcan_read_reg(®s->stat); /* If we got TX progress, the device has not hanged, * so disable the hang timer */ if (priv->need_txbug_workaround && (sources & (GRCAN_IRQ_TX | GRCAN_IRQ_TXLOSS))) { del_timer(&priv->hang_timer); } /* Frame(s) received or transmitted */ if (sources & (GRCAN_IRQ_TX | GRCAN_IRQ_RX)) { /* Disable tx/rx interrupts and schedule poll(). No need for * locking as interference from a running reset at worst leads * to an extra interrupt. */ grcan_clear_bits(®s->imr, GRCAN_IRQ_TX | GRCAN_IRQ_RX); napi_schedule(&priv->napi); } /* (Potential) error conditions to take care of */ if (sources & GRCAN_IRQ_ERRORS) grcan_err(dev, sources, status); return IRQ_HANDLED; } /* Reset device and restart operations from where they were. * * This assumes that RXCTRL & RXCTRL is properly disabled and that RX * is not ONGOING (TX might be stuck in ONGOING due to a harwrware bug * for single shot) */ static void grcan_running_reset(struct timer_list *t) { struct grcan_priv *priv = from_timer(priv, t, rr_timer); struct net_device *dev = priv->dev; struct grcan_registers __iomem *regs = priv->regs; unsigned long flags; /* This temporarily messes with eskbp, so we need to lock * priv->lock */ spin_lock_irqsave(&priv->lock, flags); priv->resetting = false; del_timer(&priv->hang_timer); del_timer(&priv->rr_timer); if (!priv->closing) { /* Save and reset - config register preserved by grcan_reset */ u32 imr = grcan_read_reg(®s->imr); u32 txaddr = grcan_read_reg(®s->txaddr); u32 txsize = grcan_read_reg(®s->txsize); u32 txwr = grcan_read_reg(®s->txwr); u32 txrd = grcan_read_reg(®s->txrd); u32 eskbp = priv->eskbp; u32 rxaddr = grcan_read_reg(®s->rxaddr); u32 rxsize = grcan_read_reg(®s->rxsize); u32 rxwr = grcan_read_reg(®s->rxwr); u32 rxrd = grcan_read_reg(®s->rxrd); grcan_reset(dev); /* Restore */ grcan_write_reg(®s->txaddr, txaddr); grcan_write_reg(®s->txsize, txsize); grcan_write_reg(®s->txwr, txwr); grcan_write_reg(®s->txrd, txrd); priv->eskbp = eskbp; grcan_write_reg(®s->rxaddr, rxaddr); grcan_write_reg(®s->rxsize, rxsize); grcan_write_reg(®s->rxwr, rxwr); grcan_write_reg(®s->rxrd, rxrd); /* Turn on device again */ grcan_write_reg(®s->imr, imr); priv->can.state = CAN_STATE_ERROR_ACTIVE; grcan_write_reg(®s->txctrl, GRCAN_TXCTRL_ENABLE | (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT ? GRCAN_TXCTRL_SINGLE : 0)); grcan_write_reg(®s->rxctrl, GRCAN_RXCTRL_ENABLE); grcan_write_reg(®s->ctrl, GRCAN_CTRL_ENABLE); /* Start queue if there is size and listen-onle mode is not * enabled */ if (grcan_txspace(priv->dma.tx.size, txwr, priv->eskbp) && !(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)) netif_wake_queue(dev); } spin_unlock_irqrestore(&priv->lock, flags); netdev_err(dev, "Device reset and restored\n"); } /* Waiting time in usecs corresponding to the transmission of three maximum * sized can frames in the given bitrate (in bits/sec). Waiting for this amount * of time makes sure that the can controller have time to finish sending or * receiving a frame with a good margin. * * usecs/sec * number of frames * bits/frame / bits/sec */ static inline u32 grcan_ongoing_wait_usecs(__u32 bitrate) { return 1000000 * 3 * GRCAN_EFF_FRAME_MAX_BITS / bitrate; } /* Set timer so that it will not fire until after a period in which the can * controller have a good margin to finish transmitting a frame unless it has * hanged */ static inline void grcan_reset_timer(struct timer_list *timer, __u32 bitrate) { u32 wait_jiffies = usecs_to_jiffies(grcan_ongoing_wait_usecs(bitrate)); mod_timer(timer, jiffies + wait_jiffies); } /* Disable channels and schedule a running reset */ static void grcan_initiate_running_reset(struct timer_list *t) { struct grcan_priv *priv = from_timer(priv, t, hang_timer); struct net_device *dev = priv->dev; struct grcan_registers __iomem *regs = priv->regs; unsigned long flags; netdev_err(dev, "Device seems hanged - reset scheduled\n"); spin_lock_irqsave(&priv->lock, flags); /* The main body of this function must never be executed again * until after an execution of grcan_running_reset */ if (!priv->resetting && !priv->closing) { priv->resetting = true; netif_stop_queue(dev); grcan_clear_bits(®s->txctrl, GRCAN_TXCTRL_ENABLE); grcan_clear_bits(®s->rxctrl, GRCAN_RXCTRL_ENABLE); grcan_reset_timer(&priv->rr_timer, priv->can.bittiming.bitrate); } spin_unlock_irqrestore(&priv->lock, flags); } static void grcan_free_dma_buffers(struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_dma *dma = &priv->dma; dma_free_coherent(&dev->dev, dma->base_size, dma->base_buf, dma->base_handle); memset(dma, 0, sizeof(*dma)); } static int grcan_allocate_dma_buffers(struct net_device *dev, size_t tsize, size_t rsize) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_dma *dma = &priv->dma; struct grcan_dma_buffer *large = rsize > tsize ? &dma->rx : &dma->tx; struct grcan_dma_buffer *small = rsize > tsize ? &dma->tx : &dma->rx; size_t shift; /* Need a whole number of GRCAN_BUFFER_ALIGNMENT for the large, * i.e. first buffer */ size_t maxs = max(tsize, rsize); size_t lsize = ALIGN(maxs, GRCAN_BUFFER_ALIGNMENT); /* Put the small buffer after that */ size_t ssize = min(tsize, rsize); /* Extra GRCAN_BUFFER_ALIGNMENT to allow for alignment */ dma->base_size = lsize + ssize + GRCAN_BUFFER_ALIGNMENT; dma->base_buf = dma_alloc_coherent(&dev->dev, dma->base_size, &dma->base_handle, GFP_KERNEL); if (!dma->base_buf) return -ENOMEM; dma->tx.size = tsize; dma->rx.size = rsize; large->handle = ALIGN(dma->base_handle, GRCAN_BUFFER_ALIGNMENT); small->handle = large->handle + lsize; shift = large->handle - dma->base_handle; large->buf = dma->base_buf + shift; small->buf = large->buf + lsize; return 0; } /* priv->lock *must* be held when calling this function */ static int grcan_start(struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; u32 confop, txctrl; grcan_reset(dev); grcan_write_reg(®s->txaddr, priv->dma.tx.handle); grcan_write_reg(®s->txsize, priv->dma.tx.size); /* regs->txwr, regs->txrd and priv->eskbp already set to 0 by reset */ grcan_write_reg(®s->rxaddr, priv->dma.rx.handle); grcan_write_reg(®s->rxsize, priv->dma.rx.size); /* regs->rxwr and regs->rxrd already set to 0 by reset */ /* Enable interrupts */ grcan_read_reg(®s->pir); grcan_write_reg(®s->imr, GRCAN_IRQ_DEFAULT); /* Enable interfaces, channels and device */ confop = GRCAN_CONF_ABORT | (priv->config.enable0 ? GRCAN_CONF_ENABLE0 : 0) | (priv->config.enable1 ? GRCAN_CONF_ENABLE1 : 0) | (priv->config.select ? GRCAN_CONF_SELECT : 0) | (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY ? GRCAN_CONF_SILENT : 0) | (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ? GRCAN_CONF_SAM : 0); grcan_write_bits(®s->conf, confop, GRCAN_CONF_OPERATION); txctrl = GRCAN_TXCTRL_ENABLE | (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT ? GRCAN_TXCTRL_SINGLE : 0); grcan_write_reg(®s->txctrl, txctrl); grcan_write_reg(®s->rxctrl, GRCAN_RXCTRL_ENABLE); grcan_write_reg(®s->ctrl, GRCAN_CTRL_ENABLE); priv->can.state = CAN_STATE_ERROR_ACTIVE; return 0; } static int grcan_set_mode(struct net_device *dev, enum can_mode mode) { struct grcan_priv *priv = netdev_priv(dev); unsigned long flags; int err = 0; if (mode == CAN_MODE_START) { /* This might be called to restart the device to recover from * bus off errors */ spin_lock_irqsave(&priv->lock, flags); if (priv->closing || priv->resetting) { err = -EBUSY; } else { netdev_info(dev, "Restarting device\n"); grcan_start(dev); if (!(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)) netif_wake_queue(dev); } spin_unlock_irqrestore(&priv->lock, flags); return err; } return -EOPNOTSUPP; } static int grcan_open(struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_dma *dma = &priv->dma; unsigned long flags; int err; /* Allocate memory */ err = grcan_allocate_dma_buffers(dev, priv->config.txsize, priv->config.rxsize); if (err) { netdev_err(dev, "could not allocate DMA buffers\n"); return err; } priv->echo_skb = kcalloc(dma->tx.size, sizeof(*priv->echo_skb), GFP_KERNEL); if (!priv->echo_skb) { err = -ENOMEM; goto exit_free_dma_buffers; } priv->can.echo_skb_max = dma->tx.size; priv->can.echo_skb = priv->echo_skb; priv->txdlc = kcalloc(dma->tx.size, sizeof(*priv->txdlc), GFP_KERNEL); if (!priv->txdlc) { err = -ENOMEM; goto exit_free_echo_skb; } /* Get can device up */ err = open_candev(dev); if (err) goto exit_free_txdlc; err = request_irq(dev->irq, grcan_interrupt, IRQF_SHARED, dev->name, dev); if (err) goto exit_close_candev; spin_lock_irqsave(&priv->lock, flags); napi_enable(&priv->napi); grcan_start(dev); if (!(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)) netif_start_queue(dev); priv->resetting = false; priv->closing = false; spin_unlock_irqrestore(&priv->lock, flags); return 0; exit_close_candev: close_candev(dev); exit_free_txdlc: kfree(priv->txdlc); exit_free_echo_skb: kfree(priv->echo_skb); exit_free_dma_buffers: grcan_free_dma_buffers(dev); return err; } static int grcan_close(struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); unsigned long flags; napi_disable(&priv->napi); spin_lock_irqsave(&priv->lock, flags); priv->closing = true; if (priv->need_txbug_workaround) { del_timer_sync(&priv->hang_timer); del_timer_sync(&priv->rr_timer); } netif_stop_queue(dev); grcan_stop_hardware(dev); priv->can.state = CAN_STATE_STOPPED; spin_unlock_irqrestore(&priv->lock, flags); free_irq(dev->irq, dev); close_candev(dev); grcan_free_dma_buffers(dev); priv->can.echo_skb_max = 0; priv->can.echo_skb = NULL; kfree(priv->echo_skb); kfree(priv->txdlc); return 0; } static int grcan_transmit_catch_up(struct net_device *dev, int budget) { struct grcan_priv *priv = netdev_priv(dev); unsigned long flags; int work_done; spin_lock_irqsave(&priv->lock, flags); work_done = catch_up_echo_skb(dev, budget, true); if (work_done) { if (!priv->resetting && !priv->closing && !(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)) netif_wake_queue(dev); /* With napi we don't get TX interrupts for a while, * so prevent a running reset while catching up */ if (priv->need_txbug_workaround) del_timer(&priv->hang_timer); } spin_unlock_irqrestore(&priv->lock, flags); return work_done; } static int grcan_receive(struct net_device *dev, int budget) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; struct grcan_dma *dma = &priv->dma; struct net_device_stats *stats = &dev->stats; struct can_frame *cf; struct sk_buff *skb; u32 wr, rd, startrd; u32 *slot; u32 i, rtr, eff, j, shift; int work_done = 0; rd = grcan_read_reg(®s->rxrd); startrd = rd; for (work_done = 0; work_done < budget; work_done++) { /* Check for packet to receive */ wr = grcan_read_reg(®s->rxwr); if (rd == wr) break; /* Take care of packet */ skb = alloc_can_skb(dev, &cf); if (skb == NULL) { netdev_err(dev, "dropping frame: skb allocation failed\n"); stats->rx_dropped++; continue; } slot = dma->rx.buf + rd; eff = slot[0] & GRCAN_MSG_IDE; rtr = slot[0] & GRCAN_MSG_RTR; if (eff) { cf->can_id = ((slot[0] & GRCAN_MSG_EID) >> GRCAN_MSG_EID_BIT); cf->can_id |= CAN_EFF_FLAG; } else { cf->can_id = ((slot[0] & GRCAN_MSG_BID) >> GRCAN_MSG_BID_BIT); } cf->can_dlc = get_can_dlc((slot[1] & GRCAN_MSG_DLC) >> GRCAN_MSG_DLC_BIT); if (rtr) { cf->can_id |= CAN_RTR_FLAG; } else { for (i = 0; i < cf->can_dlc; i++) { j = GRCAN_MSG_DATA_SLOT_INDEX(i); shift = GRCAN_MSG_DATA_SHIFT(i); cf->data[i] = (u8)(slot[j] >> shift); } } /* Update statistics and read pointer */ stats->rx_packets++; stats->rx_bytes += cf->can_dlc; netif_receive_skb(skb); rd = grcan_ring_add(rd, GRCAN_MSG_SIZE, dma->rx.size); } /* Make sure everything is read before allowing hardware to * use the memory */ mb(); /* Update read pointer - no need to check for ongoing */ if (likely(rd != startrd)) grcan_write_reg(®s->rxrd, rd); return work_done; } static int grcan_poll(struct napi_struct *napi, int budget) { struct grcan_priv *priv = container_of(napi, struct grcan_priv, napi); struct net_device *dev = priv->dev; struct grcan_registers __iomem *regs = priv->regs; unsigned long flags; int tx_work_done, rx_work_done; int rx_budget = budget / 2; int tx_budget = budget - rx_budget; /* Half of the budget for receiveing messages */ rx_work_done = grcan_receive(dev, rx_budget); /* Half of the budget for transmitting messages as that can trigger echo * frames being received */ tx_work_done = grcan_transmit_catch_up(dev, tx_budget); if (rx_work_done < rx_budget && tx_work_done < tx_budget) { napi_complete(napi); /* Guarantee no interference with a running reset that otherwise * could turn off interrupts. */ spin_lock_irqsave(&priv->lock, flags); /* Enable tx and rx interrupts again. No need to check * priv->closing as napi_disable in grcan_close is waiting for * scheduled napi calls to finish. */ grcan_set_bits(®s->imr, GRCAN_IRQ_TX | GRCAN_IRQ_RX); spin_unlock_irqrestore(&priv->lock, flags); } return rx_work_done + tx_work_done; } /* Work tx bug by waiting while for the risky situation to clear. If that fails, * drop a frame in one-shot mode or indicate a busy device otherwise. * * Returns 0 on successful wait. Otherwise it sets *netdev_tx_status to the * value that should be returned by grcan_start_xmit when aborting the xmit. */ static int grcan_txbug_workaround(struct net_device *dev, struct sk_buff *skb, u32 txwr, u32 oneshotmode, netdev_tx_t *netdev_tx_status) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; struct grcan_dma *dma = &priv->dma; int i; unsigned long flags; /* Wait a while for ongoing to be cleared or read pointer to catch up to * write pointer. The latter is needed due to a bug in older versions of * GRCAN in which ONGOING is not cleared properly one-shot mode when a * transmission fails. */ for (i = 0; i < GRCAN_SHORTWAIT_USECS; i++) { udelay(1); if (!grcan_read_bits(®s->txctrl, GRCAN_TXCTRL_ONGOING) || grcan_read_reg(®s->txrd) == txwr) { return 0; } } /* Clean up, in case the situation was not resolved */ spin_lock_irqsave(&priv->lock, flags); if (!priv->resetting && !priv->closing) { /* Queue might have been stopped earlier in grcan_start_xmit */ if (grcan_txspace(dma->tx.size, txwr, priv->eskbp)) netif_wake_queue(dev); /* Set a timer to resolve a hanged tx controller */ if (!timer_pending(&priv->hang_timer)) grcan_reset_timer(&priv->hang_timer, priv->can.bittiming.bitrate); } spin_unlock_irqrestore(&priv->lock, flags); if (oneshotmode) { /* In one-shot mode we should never end up here because * then the interrupt handler increases txrd on TXLOSS, * but it is consistent with one-shot mode to drop the * frame in this case. */ kfree_skb(skb); *netdev_tx_status = NETDEV_TX_OK; } else { /* In normal mode the socket-can transmission queue get * to keep the frame so that it can be retransmitted * later */ *netdev_tx_status = NETDEV_TX_BUSY; } return -EBUSY; } /* Notes on the tx cyclic buffer handling: * * regs->txwr - the next slot for the driver to put data to be sent * regs->txrd - the next slot for the device to read data * priv->eskbp - the next slot for the driver to call can_put_echo_skb for * * grcan_start_xmit can enter more messages as long as regs->txwr does * not reach priv->eskbp (within 1 message gap) * * The device sends messages until regs->txrd reaches regs->txwr * * The interrupt calls handler calls can_put_echo_skb until * priv->eskbp reaches regs->txrd */ static netdev_tx_t grcan_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct grcan_priv *priv = netdev_priv(dev); struct grcan_registers __iomem *regs = priv->regs; struct grcan_dma *dma = &priv->dma; struct can_frame *cf = (struct can_frame *)skb->data; u32 id, txwr, txrd, space, txctrl; int slotindex; u32 *slot; u32 i, rtr, eff, dlc, tmp, err; int j, shift; unsigned long flags; u32 oneshotmode = priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT; if (can_dropped_invalid_skb(dev, skb)) return NETDEV_TX_OK; /* Trying to transmit in silent mode will generate error interrupts, but * this should never happen - the queue should not have been started. */ if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) return NETDEV_TX_BUSY; /* Reads of priv->eskbp and shut-downs of the queue needs to * be atomic towards the updates to priv->eskbp and wake-ups * of the queue in the interrupt handler. */ spin_lock_irqsave(&priv->lock, flags); txwr = grcan_read_reg(®s->txwr); space = grcan_txspace(dma->tx.size, txwr, priv->eskbp); slotindex = txwr / GRCAN_MSG_SIZE; slot = dma->tx.buf + txwr; if (unlikely(space == 1)) netif_stop_queue(dev); spin_unlock_irqrestore(&priv->lock, flags); /* End of critical section*/ /* This should never happen. If circular buffer is full, the * netif_stop_queue should have been stopped already. */ if (unlikely(!space)) { netdev_err(dev, "No buffer space, but queue is non-stopped.\n"); return NETDEV_TX_BUSY; } /* Convert and write CAN message to DMA buffer */ eff = cf->can_id & CAN_EFF_FLAG; rtr = cf->can_id & CAN_RTR_FLAG; id = cf->can_id & (eff ? CAN_EFF_MASK : CAN_SFF_MASK); dlc = cf->can_dlc; if (eff) tmp = (id << GRCAN_MSG_EID_BIT) & GRCAN_MSG_EID; else tmp = (id << GRCAN_MSG_BID_BIT) & GRCAN_MSG_BID; slot[0] = (eff ? GRCAN_MSG_IDE : 0) | (rtr ? GRCAN_MSG_RTR : 0) | tmp; slot[1] = ((dlc << GRCAN_MSG_DLC_BIT) & GRCAN_MSG_DLC); slot[2] = 0; slot[3] = 0; for (i = 0; i < dlc; i++) { j = GRCAN_MSG_DATA_SLOT_INDEX(i); shift = GRCAN_MSG_DATA_SHIFT(i); slot[j] |= cf->data[i] << shift; } /* Checking that channel has not been disabled. These cases * should never happen */ txctrl = grcan_read_reg(®s->txctrl); if (!(txctrl & GRCAN_TXCTRL_ENABLE)) netdev_err(dev, "tx channel spuriously disabled\n"); if (oneshotmode && !(txctrl & GRCAN_TXCTRL_SINGLE)) netdev_err(dev, "one-shot mode spuriously disabled\n"); /* Bug workaround for old version of grcan where updating txwr * in the same clock cycle as the controller updates txrd to * the current txwr could hang the can controller */ if (priv->need_txbug_workaround) { txrd = grcan_read_reg(®s->txrd); if (unlikely(grcan_ring_sub(txwr, txrd, dma->tx.size) == 1)) { netdev_tx_t txstatus; err = grcan_txbug_workaround(dev, skb, txwr, oneshotmode, &txstatus); if (err) return txstatus; } } /* Prepare skb for echoing. This must be after the bug workaround above * as ownership of the skb is passed on by calling can_put_echo_skb. * Returning NETDEV_TX_BUSY or accessing skb or cf after a call to * can_put_echo_skb would be an error unless other measures are * taken. */ priv->txdlc[slotindex] = cf->can_dlc; /* Store dlc for statistics */ can_put_echo_skb(skb, dev, slotindex); /* Make sure everything is written before allowing hardware to * read from the memory */ wmb(); /* Update write pointer to start transmission */ grcan_write_reg(®s->txwr, grcan_ring_add(txwr, GRCAN_MSG_SIZE, dma->tx.size)); return NETDEV_TX_OK; } /* ========== Setting up sysfs interface and module parameters ========== */ #define GRCAN_NOT_BOOL(unsigned_val) ((unsigned_val) > 1) #define GRCAN_MODULE_PARAM(name, mtype, valcheckf, desc) \ static void grcan_sanitize_##name(struct platform_device *pd) \ { \ struct grcan_device_config grcan_default_config \ = GRCAN_DEFAULT_DEVICE_CONFIG; \ if (valcheckf(grcan_module_config.name)) { \ dev_err(&pd->dev, \ "Invalid module parameter value for " \ #name " - setting default\n"); \ grcan_module_config.name = \ grcan_default_config.name; \ } \ } \ module_param_named(name, grcan_module_config.name, \ mtype, 0444); \ MODULE_PARM_DESC(name, desc) #define GRCAN_CONFIG_ATTR(name, desc) \ static ssize_t grcan_store_##name(struct device *sdev, \ struct device_attribute *att, \ const char *buf, \ size_t count) \ { \ struct net_device *dev = to_net_dev(sdev); \ struct grcan_priv *priv = netdev_priv(dev); \ u8 val; \ int ret; \ if (dev->flags & IFF_UP) \ return -EBUSY; \ ret = kstrtou8(buf, 0, &val); \ if (ret < 0 || val > 1) \ return -EINVAL; \ priv->config.name = val; \ return count; \ } \ static ssize_t grcan_show_##name(struct device *sdev, \ struct device_attribute *att, \ char *buf) \ { \ struct net_device *dev = to_net_dev(sdev); \ struct grcan_priv *priv = netdev_priv(dev); \ return sprintf(buf, "%d\n", priv->config.name); \ } \ static DEVICE_ATTR(name, 0644, \ grcan_show_##name, \ grcan_store_##name); \ GRCAN_MODULE_PARAM(name, ushort, GRCAN_NOT_BOOL, desc) /* The following configuration options are made available both via module * parameters and writable sysfs files. See the chapter about GRCAN in the * documentation for the GRLIB VHDL library for further details. */ GRCAN_CONFIG_ATTR(enable0, "Configuration of physical interface 0. Determines\n" \ "the \"Enable 0\" bit of the configuration register.\n" \ "Format: 0 | 1\nDefault: 0\n"); GRCAN_CONFIG_ATTR(enable1, "Configuration of physical interface 1. Determines\n" \ "the \"Enable 1\" bit of the configuration register.\n" \ "Format: 0 | 1\nDefault: 0\n"); GRCAN_CONFIG_ATTR(select, "Select which physical interface to use.\n" \ "Format: 0 | 1\nDefault: 0\n"); /* The tx and rx buffer size configuration options are only available via module * parameters. */ GRCAN_MODULE_PARAM(txsize, uint, GRCAN_INVALID_BUFFER_SIZE, "Sets the size of the tx buffer.\n" \ "Format: <unsigned int> where (txsize & ~0x1fffc0) == 0\n" \ "Default: 1024\n"); GRCAN_MODULE_PARAM(rxsize, uint, GRCAN_INVALID_BUFFER_SIZE, "Sets the size of the rx buffer.\n" \ "Format: <unsigned int> where (size & ~0x1fffc0) == 0\n" \ "Default: 1024\n"); /* Function that makes sure that configuration done using * module parameters are set to valid values */ static void grcan_sanitize_module_config(struct platform_device *ofdev) { grcan_sanitize_enable0(ofdev); grcan_sanitize_enable1(ofdev); grcan_sanitize_select(ofdev); grcan_sanitize_txsize(ofdev); grcan_sanitize_rxsize(ofdev); } static const struct attribute *const sysfs_grcan_attrs[] = { /* Config attrs */ &dev_attr_enable0.attr, &dev_attr_enable1.attr, &dev_attr_select.attr, NULL, }; static const struct attribute_group sysfs_grcan_group = { .name = "grcan", .attrs = (struct attribute **)sysfs_grcan_attrs, }; /* ========== Setting up the driver ========== */ static const struct net_device_ops grcan_netdev_ops = { .ndo_open = grcan_open, .ndo_stop = grcan_close, .ndo_start_xmit = grcan_start_xmit, .ndo_change_mtu = can_change_mtu, }; static int grcan_setup_netdev(struct platform_device *ofdev, void __iomem *base, int irq, u32 ambafreq, bool txbug) { struct net_device *dev; struct grcan_priv *priv; struct grcan_registers __iomem *regs; int err; dev = alloc_candev(sizeof(struct grcan_priv), 0); if (!dev) return -ENOMEM; dev->irq = irq; dev->flags |= IFF_ECHO; dev->netdev_ops = &grcan_netdev_ops; dev->sysfs_groups[0] = &sysfs_grcan_group; priv = netdev_priv(dev); memcpy(&priv->config, &grcan_module_config, sizeof(struct grcan_device_config)); priv->dev = dev; priv->regs = base; priv->can.bittiming_const = &grcan_bittiming_const; priv->can.do_set_bittiming = grcan_set_bittiming; priv->can.do_set_mode = grcan_set_mode; priv->can.do_get_berr_counter = grcan_get_berr_counter; priv->can.clock.freq = ambafreq; priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_ONE_SHOT; priv->need_txbug_workaround = txbug; /* Discover if triple sampling is supported by hardware */ regs = priv->regs; grcan_set_bits(®s->ctrl, GRCAN_CTRL_RESET); grcan_set_bits(®s->conf, GRCAN_CONF_SAM); if (grcan_read_bits(®s->conf, GRCAN_CONF_SAM)) { priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES; dev_dbg(&ofdev->dev, "Hardware supports triple-sampling\n"); } spin_lock_init(&priv->lock); if (priv->need_txbug_workaround) { timer_setup(&priv->rr_timer, grcan_running_reset, 0); timer_setup(&priv->hang_timer, grcan_initiate_running_reset, 0); } netif_napi_add(dev, &priv->napi, grcan_poll, GRCAN_NAPI_WEIGHT); SET_NETDEV_DEV(dev, &ofdev->dev); dev_info(&ofdev->dev, "regs=0x%p, irq=%d, clock=%d\n", priv->regs, dev->irq, priv->can.clock.freq); err = register_candev(dev); if (err) goto exit_free_candev; platform_set_drvdata(ofdev, dev); /* Reset device to allow bit-timing to be set. No need to call * grcan_reset at this stage. That is done in grcan_open. */ grcan_write_reg(®s->ctrl, GRCAN_CTRL_RESET); return 0; exit_free_candev: free_candev(dev); return err; } static int grcan_probe(struct platform_device *ofdev) { struct device_node *np = ofdev->dev.of_node; struct resource *res; u32 sysid, ambafreq; int irq, err; void __iomem *base; bool txbug = true; /* Compare GRLIB version number with the first that does not * have the tx bug (see start_xmit) */ err = of_property_read_u32(np, "systemid", &sysid); if (!err && ((sysid & GRLIB_VERSION_MASK) >= GRCAN_TXBUG_SAFE_GRLIB_VERSION)) txbug = false; err = of_property_read_u32(np, "freq", &ambafreq); if (err) { dev_err(&ofdev->dev, "unable to fetch \"freq\" property\n"); goto exit_error; } res = platform_get_resource(ofdev, IORESOURCE_MEM, 0); base = devm_ioremap_resource(&ofdev->dev, res); if (IS_ERR(base)) { err = PTR_ERR(base); goto exit_error; } irq = irq_of_parse_and_map(np, GRCAN_IRQIX_IRQ); if (!irq) { dev_err(&ofdev->dev, "no irq found\n"); err = -ENODEV; goto exit_error; } grcan_sanitize_module_config(ofdev); err = grcan_setup_netdev(ofdev, base, irq, ambafreq, txbug); if (err) goto exit_dispose_irq; return 0; exit_dispose_irq: irq_dispose_mapping(irq); exit_error: dev_err(&ofdev->dev, "%s socket CAN driver initialization failed with error %d\n", DRV_NAME, err); return err; } static int grcan_remove(struct platform_device *ofdev) { struct net_device *dev = platform_get_drvdata(ofdev); struct grcan_priv *priv = netdev_priv(dev); unregister_candev(dev); /* Will in turn call grcan_close */ irq_dispose_mapping(dev->irq); netif_napi_del(&priv->napi); free_candev(dev); return 0; } static const struct of_device_id grcan_match[] = { {.name = "GAISLER_GRCAN"}, {.name = "01_03d"}, {.name = "GAISLER_GRHCAN"}, {.name = "01_034"}, {}, }; MODULE_DEVICE_TABLE(of, grcan_match); static struct platform_driver grcan_driver = { .driver = { .name = DRV_NAME, .of_match_table = grcan_match, }, .probe = grcan_probe, .remove = grcan_remove, }; module_platform_driver(grcan_driver); MODULE_AUTHOR("Aeroflex Gaisler AB."); MODULE_DESCRIPTION("Socket CAN driver for Aeroflex Gaisler GRCAN"); MODULE_LICENSE("GPL");
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