diff options
Diffstat (limited to 'drivers/net/can/ti_hecc.c')
| -rw-r--r-- | drivers/net/can/ti_hecc.c | 1038 |
1 files changed, 1038 insertions, 0 deletions
diff --git a/drivers/net/can/ti_hecc.c b/drivers/net/can/ti_hecc.c new file mode 100644 index 0000000000..5aab440074 --- /dev/null +++ b/drivers/net/can/ti_hecc.c @@ -0,0 +1,1038 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TI HECC (CAN) device driver + * + * This driver supports TI's HECC (High End CAN Controller module) and the + * specs for the same is available at <http://www.ti.com> + * + * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/ + * Copyright (C) 2019 Jeroen Hofstee <jhofstee@victronenergy.com> + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/interrupt.h> +#include <linux/errno.h> +#include <linux/ethtool.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/platform_device.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/regulator/consumer.h> + +#include <linux/can/dev.h> +#include <linux/can/error.h> +#include <linux/can/rx-offload.h> + +#define DRV_NAME "ti_hecc" +#define HECC_MODULE_VERSION "0.7" +MODULE_VERSION(HECC_MODULE_VERSION); +#define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION + +/* TX / RX Mailbox Configuration */ +#define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */ +#define MAX_TX_PRIO 0x3F /* hardware value - do not change */ + +/* Important Note: TX mailbox configuration + * TX mailboxes should be restricted to the number of SKB buffers to avoid + * maintaining SKB buffers separately. TX mailboxes should be a power of 2 + * for the mailbox logic to work. Top mailbox numbers are reserved for RX + * and lower mailboxes for TX. + * + * HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT + * 4 (default) 2 + * 8 3 + * 16 4 + */ +#define HECC_MB_TX_SHIFT 2 /* as per table above */ +#define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT) + +#define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT) +#define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT) +#define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1) +#define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK) + +/* RX mailbox configuration + * + * The remaining mailboxes are used for reception and are delivered + * based on their timestamp, to avoid a hardware race when CANME is + * changed while CAN-bus traffic is being received. + */ +#define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX) +#define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1) +#define HECC_RX_LAST_MBOX (HECC_MAX_TX_MBOX) + +/* TI HECC module registers */ +#define HECC_CANME 0x0 /* Mailbox enable */ +#define HECC_CANMD 0x4 /* Mailbox direction */ +#define HECC_CANTRS 0x8 /* Transmit request set */ +#define HECC_CANTRR 0xC /* Transmit request */ +#define HECC_CANTA 0x10 /* Transmission acknowledge */ +#define HECC_CANAA 0x14 /* Abort acknowledge */ +#define HECC_CANRMP 0x18 /* Receive message pending */ +#define HECC_CANRML 0x1C /* Receive message lost */ +#define HECC_CANRFP 0x20 /* Remote frame pending */ +#define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */ +#define HECC_CANMC 0x28 /* Master control */ +#define HECC_CANBTC 0x2C /* Bit timing configuration */ +#define HECC_CANES 0x30 /* Error and status */ +#define HECC_CANTEC 0x34 /* Transmit error counter */ +#define HECC_CANREC 0x38 /* Receive error counter */ +#define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */ +#define HECC_CANGIM 0x40 /* Global interrupt mask */ +#define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */ +#define HECC_CANMIM 0x48 /* Mailbox interrupt mask */ +#define HECC_CANMIL 0x4C /* Mailbox interrupt level */ +#define HECC_CANOPC 0x50 /* Overwrite protection control */ +#define HECC_CANTIOC 0x54 /* Transmit I/O control */ +#define HECC_CANRIOC 0x58 /* Receive I/O control */ +#define HECC_CANLNT 0x5C /* HECC only: Local network time */ +#define HECC_CANTOC 0x60 /* HECC only: Time-out control */ +#define HECC_CANTOS 0x64 /* HECC only: Time-out status */ +#define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */ +#define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */ + +/* TI HECC RAM registers */ +#define HECC_CANMOTS 0x80 /* Message object time stamp */ + +/* Mailbox registers */ +#define HECC_CANMID 0x0 +#define HECC_CANMCF 0x4 +#define HECC_CANMDL 0x8 +#define HECC_CANMDH 0xC + +#define HECC_SET_REG 0xFFFFFFFF +#define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */ +#define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */ + +#define HECC_CANMC_SCM BIT(13) /* SCC compat mode */ +#define HECC_CANMC_CCR BIT(12) /* Change config request */ +#define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */ +#define HECC_CANMC_ABO BIT(7) /* Auto Bus On */ +#define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */ +#define HECC_CANMC_SRES BIT(5) /* Software reset */ + +#define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */ +#define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */ + +#define HECC_CANMID_IDE BIT(31) /* Extended frame format */ +#define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */ +#define HECC_CANMID_AAM BIT(29) /* Auto answer mode */ + +#define HECC_CANES_FE BIT(24) /* form error */ +#define HECC_CANES_BE BIT(23) /* bit error */ +#define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */ +#define HECC_CANES_CRCE BIT(21) /* CRC error */ +#define HECC_CANES_SE BIT(20) /* stuff bit error */ +#define HECC_CANES_ACKE BIT(19) /* ack error */ +#define HECC_CANES_BO BIT(18) /* Bus off status */ +#define HECC_CANES_EP BIT(17) /* Error passive status */ +#define HECC_CANES_EW BIT(16) /* Error warning status */ +#define HECC_CANES_SMA BIT(5) /* suspend mode ack */ +#define HECC_CANES_CCE BIT(4) /* Change config enabled */ +#define HECC_CANES_PDA BIT(3) /* Power down mode ack */ + +#define HECC_CANBTC_SAM BIT(7) /* sample points */ + +#define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\ + HECC_CANES_CRCE | HECC_CANES_SE |\ + HECC_CANES_ACKE) +#define HECC_CANES_FLAGS (HECC_BUS_ERROR | HECC_CANES_BO |\ + HECC_CANES_EP | HECC_CANES_EW) + +#define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */ + +#define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */ +#define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */ +#define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */ +#define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */ +#define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */ +#define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */ +#define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */ +#define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */ +#define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */ +#define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */ +#define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */ +#define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */ +#define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */ +#define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */ +#define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */ + +/* CAN Bittiming constants as per HECC specs */ +static const struct can_bittiming_const ti_hecc_bittiming_const = { + .name = DRV_NAME, + .tseg1_min = 1, + .tseg1_max = 16, + .tseg2_min = 1, + .tseg2_max = 8, + .sjw_max = 4, + .brp_min = 1, + .brp_max = 256, + .brp_inc = 1, +}; + +struct ti_hecc_priv { + struct can_priv can; /* MUST be first member/field */ + struct can_rx_offload offload; + struct net_device *ndev; + struct clk *clk; + void __iomem *base; + void __iomem *hecc_ram; + void __iomem *mbx; + bool use_hecc1int; + spinlock_t mbx_lock; /* CANME register needs protection */ + u32 tx_head; + u32 tx_tail; + struct regulator *reg_xceiver; +}; + +static inline int get_tx_head_mb(struct ti_hecc_priv *priv) +{ + return priv->tx_head & HECC_TX_MB_MASK; +} + +static inline int get_tx_tail_mb(struct ti_hecc_priv *priv) +{ + return priv->tx_tail & HECC_TX_MB_MASK; +} + +static inline int get_tx_head_prio(struct ti_hecc_priv *priv) +{ + return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO; +} + +static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val) +{ + __raw_writel(val, priv->hecc_ram + mbxno * 4); +} + +static inline u32 hecc_read_stamp(struct ti_hecc_priv *priv, u32 mbxno) +{ + return __raw_readl(priv->hecc_ram + HECC_CANMOTS + mbxno * 4); +} + +static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno, + u32 reg, u32 val) +{ + __raw_writel(val, priv->mbx + mbxno * 0x10 + reg); +} + +static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg) +{ + return __raw_readl(priv->mbx + mbxno * 0x10 + reg); +} + +static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val) +{ + __raw_writel(val, priv->base + reg); +} + +static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg) +{ + return __raw_readl(priv->base + reg); +} + +static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg, + u32 bit_mask) +{ + hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask); +} + +static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg, + u32 bit_mask) +{ + hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask); +} + +static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask) +{ + return (hecc_read(priv, reg) & bit_mask) ? 1 : 0; +} + +static int ti_hecc_set_btc(struct ti_hecc_priv *priv) +{ + struct can_bittiming *bit_timing = &priv->can.bittiming; + u32 can_btc; + + can_btc = (bit_timing->phase_seg2 - 1) & 0x7; + can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1) + & 0xF) << 3; + if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) { + if (bit_timing->brp > 4) + can_btc |= HECC_CANBTC_SAM; + else + netdev_warn(priv->ndev, + "WARN: Triple sampling not set due to h/w limitations"); + } + can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8; + can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16; + + /* ERM being set to 0 by default meaning resync at falling edge */ + + hecc_write(priv, HECC_CANBTC, can_btc); + netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc); + + return 0; +} + +static int ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv, + int on) +{ + if (!priv->reg_xceiver) + return 0; + + if (on) + return regulator_enable(priv->reg_xceiver); + else + return regulator_disable(priv->reg_xceiver); +} + +static void ti_hecc_reset(struct net_device *ndev) +{ + u32 cnt; + struct ti_hecc_priv *priv = netdev_priv(ndev); + + netdev_dbg(ndev, "resetting hecc ...\n"); + hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES); + + /* Set change control request and wait till enabled */ + hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR); + + /* INFO: It has been observed that at times CCE bit may not be + * set and hw seems to be ok even if this bit is not set so + * timing out with a timing of 1ms to respect the specs + */ + cnt = HECC_CCE_WAIT_COUNT; + while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) { + --cnt; + udelay(10); + } + + /* Note: On HECC, BTC can be programmed only in initialization mode, so + * it is expected that the can bittiming parameters are set via ip + * utility before the device is opened + */ + ti_hecc_set_btc(priv); + + /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */ + hecc_write(priv, HECC_CANMC, 0); + + /* INFO: CAN net stack handles bus off and hence disabling auto-bus-on + * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO); + */ + + /* INFO: It has been observed that at times CCE bit may not be + * set and hw seems to be ok even if this bit is not set so + */ + cnt = HECC_CCE_WAIT_COUNT; + while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) { + --cnt; + udelay(10); + } + + /* Enable TX and RX I/O Control pins */ + hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN); + hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN); + + /* Clear registers for clean operation */ + hecc_write(priv, HECC_CANTA, HECC_SET_REG); + hecc_write(priv, HECC_CANRMP, HECC_SET_REG); + hecc_write(priv, HECC_CANGIF0, HECC_SET_REG); + hecc_write(priv, HECC_CANGIF1, HECC_SET_REG); + hecc_write(priv, HECC_CANME, 0); + hecc_write(priv, HECC_CANMD, 0); + + /* SCC compat mode NOT supported (and not needed too) */ + hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM); +} + +static void ti_hecc_start(struct net_device *ndev) +{ + struct ti_hecc_priv *priv = netdev_priv(ndev); + u32 cnt, mbxno, mbx_mask; + + /* put HECC in initialization mode and set btc */ + ti_hecc_reset(ndev); + + priv->tx_head = HECC_TX_MASK; + priv->tx_tail = HECC_TX_MASK; + + /* Enable local and global acceptance mask registers */ + hecc_write(priv, HECC_CANGAM, HECC_SET_REG); + + /* Prepare configured mailboxes to receive messages */ + for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) { + mbxno = HECC_MAX_MAILBOXES - 1 - cnt; + mbx_mask = BIT(mbxno); + hecc_clear_bit(priv, HECC_CANME, mbx_mask); + hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME); + hecc_write_lam(priv, mbxno, HECC_SET_REG); + hecc_set_bit(priv, HECC_CANMD, mbx_mask); + hecc_set_bit(priv, HECC_CANME, mbx_mask); + hecc_set_bit(priv, HECC_CANMIM, mbx_mask); + } + + /* Enable tx interrupts */ + hecc_set_bit(priv, HECC_CANMIM, BIT(HECC_MAX_TX_MBOX) - 1); + + /* Prevent message over-write to create a rx fifo, but not for + * the lowest priority mailbox, since that allows detecting + * overflows instead of the hardware silently dropping the + * messages. + */ + mbx_mask = ~BIT(HECC_RX_LAST_MBOX); + hecc_write(priv, HECC_CANOPC, mbx_mask); + + /* Enable interrupts */ + if (priv->use_hecc1int) { + hecc_write(priv, HECC_CANMIL, HECC_SET_REG); + hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK | + HECC_CANGIM_I1EN | HECC_CANGIM_SIL); + } else { + hecc_write(priv, HECC_CANMIL, 0); + hecc_write(priv, HECC_CANGIM, + HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN); + } + priv->can.state = CAN_STATE_ERROR_ACTIVE; +} + +static void ti_hecc_stop(struct net_device *ndev) +{ + struct ti_hecc_priv *priv = netdev_priv(ndev); + + /* Disable the CPK; stop sending, erroring and acking */ + hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR); + + /* Disable interrupts and disable mailboxes */ + hecc_write(priv, HECC_CANGIM, 0); + hecc_write(priv, HECC_CANMIM, 0); + hecc_write(priv, HECC_CANME, 0); + priv->can.state = CAN_STATE_STOPPED; +} + +static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode) +{ + int ret = 0; + + switch (mode) { + case CAN_MODE_START: + ti_hecc_start(ndev); + netif_wake_queue(ndev); + break; + default: + ret = -EOPNOTSUPP; + break; + } + + return ret; +} + +static int ti_hecc_get_berr_counter(const struct net_device *ndev, + struct can_berr_counter *bec) +{ + struct ti_hecc_priv *priv = netdev_priv(ndev); + + bec->txerr = hecc_read(priv, HECC_CANTEC); + bec->rxerr = hecc_read(priv, HECC_CANREC); + + return 0; +} + +/* ti_hecc_xmit: HECC Transmit + * + * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the + * priority of the mailbox for transmission is dependent upon priority setting + * field in mailbox registers. The mailbox with highest value in priority field + * is transmitted first. Only when two mailboxes have the same value in + * priority field the highest numbered mailbox is transmitted first. + * + * To utilize the HECC priority feature as described above we start with the + * highest numbered mailbox with highest priority level and move on to the next + * mailbox with the same priority level and so on. Once we loop through all the + * transmit mailboxes we choose the next priority level (lower) and so on + * until we reach the lowest priority level on the lowest numbered mailbox + * when we stop transmission until all mailboxes are transmitted and then + * restart at highest numbered mailbox with highest priority. + * + * Two counters (head and tail) are used to track the next mailbox to transmit + * and to track the echo buffer for already transmitted mailbox. The queue + * is stopped when all the mailboxes are busy or when there is a priority + * value roll-over happens. + */ +static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev) +{ + struct ti_hecc_priv *priv = netdev_priv(ndev); + struct can_frame *cf = (struct can_frame *)skb->data; + u32 mbxno, mbx_mask, data; + unsigned long flags; + + if (can_dev_dropped_skb(ndev, skb)) + return NETDEV_TX_OK; + + mbxno = get_tx_head_mb(priv); + mbx_mask = BIT(mbxno); + spin_lock_irqsave(&priv->mbx_lock, flags); + if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) { + spin_unlock_irqrestore(&priv->mbx_lock, flags); + netif_stop_queue(ndev); + netdev_err(priv->ndev, + "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n", + priv->tx_head, priv->tx_tail); + return NETDEV_TX_BUSY; + } + spin_unlock_irqrestore(&priv->mbx_lock, flags); + + /* Prepare mailbox for transmission */ + data = cf->len | (get_tx_head_prio(priv) << 8); + if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */ + data |= HECC_CANMCF_RTR; + hecc_write_mbx(priv, mbxno, HECC_CANMCF, data); + + if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */ + data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE; + else /* Standard frame format */ + data = (cf->can_id & CAN_SFF_MASK) << 18; + hecc_write_mbx(priv, mbxno, HECC_CANMID, data); + hecc_write_mbx(priv, mbxno, HECC_CANMDL, + be32_to_cpu(*(__be32 *)(cf->data))); + if (cf->len > 4) + hecc_write_mbx(priv, mbxno, HECC_CANMDH, + be32_to_cpu(*(__be32 *)(cf->data + 4))); + else + *(u32 *)(cf->data + 4) = 0; + can_put_echo_skb(skb, ndev, mbxno, 0); + + spin_lock_irqsave(&priv->mbx_lock, flags); + --priv->tx_head; + if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) || + (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) { + netif_stop_queue(ndev); + } + hecc_set_bit(priv, HECC_CANME, mbx_mask); + spin_unlock_irqrestore(&priv->mbx_lock, flags); + + hecc_write(priv, HECC_CANTRS, mbx_mask); + + return NETDEV_TX_OK; +} + +static inline +struct ti_hecc_priv *rx_offload_to_priv(struct can_rx_offload *offload) +{ + return container_of(offload, struct ti_hecc_priv, offload); +} + +static struct sk_buff *ti_hecc_mailbox_read(struct can_rx_offload *offload, + unsigned int mbxno, u32 *timestamp, + bool drop) +{ + struct ti_hecc_priv *priv = rx_offload_to_priv(offload); + struct sk_buff *skb; + struct can_frame *cf; + u32 data, mbx_mask; + + mbx_mask = BIT(mbxno); + + if (unlikely(drop)) { + skb = ERR_PTR(-ENOBUFS); + goto mark_as_read; + } + + skb = alloc_can_skb(offload->dev, &cf); + if (unlikely(!skb)) { + skb = ERR_PTR(-ENOMEM); + goto mark_as_read; + } + + data = hecc_read_mbx(priv, mbxno, HECC_CANMID); + if (data & HECC_CANMID_IDE) + cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG; + else + cf->can_id = (data >> 18) & CAN_SFF_MASK; + + data = hecc_read_mbx(priv, mbxno, HECC_CANMCF); + if (data & HECC_CANMCF_RTR) + cf->can_id |= CAN_RTR_FLAG; + cf->len = can_cc_dlc2len(data & 0xF); + + data = hecc_read_mbx(priv, mbxno, HECC_CANMDL); + *(__be32 *)(cf->data) = cpu_to_be32(data); + if (cf->len > 4) { + data = hecc_read_mbx(priv, mbxno, HECC_CANMDH); + *(__be32 *)(cf->data + 4) = cpu_to_be32(data); + } + + *timestamp = hecc_read_stamp(priv, mbxno); + + /* Check for FIFO overrun. + * + * All but the last RX mailbox have activated overwrite + * protection. So skip check for overrun, if we're not + * handling the last RX mailbox. + * + * As the overwrite protection for the last RX mailbox is + * disabled, the CAN core might update while we're reading + * it. This means the skb might be inconsistent. + * + * Return an error to let rx-offload discard this CAN frame. + */ + if (unlikely(mbxno == HECC_RX_LAST_MBOX && + hecc_read(priv, HECC_CANRML) & mbx_mask)) + skb = ERR_PTR(-ENOBUFS); + + mark_as_read: + hecc_write(priv, HECC_CANRMP, mbx_mask); + + return skb; +} + +static int ti_hecc_error(struct net_device *ndev, int int_status, + int err_status) +{ + struct ti_hecc_priv *priv = netdev_priv(ndev); + struct can_frame *cf; + struct sk_buff *skb; + u32 timestamp; + int err; + + if (err_status & HECC_BUS_ERROR) { + /* propagate the error condition to the can stack */ + skb = alloc_can_err_skb(ndev, &cf); + if (!skb) { + if (net_ratelimit()) + netdev_err(priv->ndev, + "%s: alloc_can_err_skb() failed\n", + __func__); + return -ENOMEM; + } + + ++priv->can.can_stats.bus_error; + cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT; + if (err_status & HECC_CANES_FE) + cf->data[2] |= CAN_ERR_PROT_FORM; + if (err_status & HECC_CANES_BE) + cf->data[2] |= CAN_ERR_PROT_BIT; + if (err_status & HECC_CANES_SE) + cf->data[2] |= CAN_ERR_PROT_STUFF; + if (err_status & HECC_CANES_CRCE) + cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; + if (err_status & HECC_CANES_ACKE) + cf->data[3] = CAN_ERR_PROT_LOC_ACK; + + timestamp = hecc_read(priv, HECC_CANLNT); + err = can_rx_offload_queue_timestamp(&priv->offload, skb, + timestamp); + if (err) + ndev->stats.rx_fifo_errors++; + } + + hecc_write(priv, HECC_CANES, HECC_CANES_FLAGS); + + return 0; +} + +static void ti_hecc_change_state(struct net_device *ndev, + enum can_state rx_state, + enum can_state tx_state) +{ + struct ti_hecc_priv *priv = netdev_priv(ndev); + struct can_frame *cf; + struct sk_buff *skb; + u32 timestamp; + int err; + + skb = alloc_can_err_skb(priv->ndev, &cf); + if (unlikely(!skb)) { + priv->can.state = max(tx_state, rx_state); + return; + } + + can_change_state(priv->ndev, cf, tx_state, rx_state); + + if (max(tx_state, rx_state) != CAN_STATE_BUS_OFF) { + cf->can_id |= CAN_ERR_CNT; + cf->data[6] = hecc_read(priv, HECC_CANTEC); + cf->data[7] = hecc_read(priv, HECC_CANREC); + } + + timestamp = hecc_read(priv, HECC_CANLNT); + err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp); + if (err) + ndev->stats.rx_fifo_errors++; +} + +static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id) +{ + struct net_device *ndev = (struct net_device *)dev_id; + struct ti_hecc_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + u32 mbxno, mbx_mask, int_status, err_status, stamp; + unsigned long flags, rx_pending; + u32 handled = 0; + + int_status = hecc_read(priv, + priv->use_hecc1int ? + HECC_CANGIF1 : HECC_CANGIF0); + + if (!int_status) + return IRQ_NONE; + + err_status = hecc_read(priv, HECC_CANES); + if (unlikely(err_status & HECC_CANES_FLAGS)) + ti_hecc_error(ndev, int_status, err_status); + + if (unlikely(int_status & HECC_CANGIM_DEF_MASK)) { + enum can_state rx_state, tx_state; + u32 rec = hecc_read(priv, HECC_CANREC); + u32 tec = hecc_read(priv, HECC_CANTEC); + + if (int_status & HECC_CANGIF_WLIF) { + handled |= HECC_CANGIF_WLIF; + rx_state = rec >= tec ? CAN_STATE_ERROR_WARNING : 0; + tx_state = rec <= tec ? CAN_STATE_ERROR_WARNING : 0; + netdev_dbg(priv->ndev, "Error Warning interrupt\n"); + ti_hecc_change_state(ndev, rx_state, tx_state); + } + + if (int_status & HECC_CANGIF_EPIF) { + handled |= HECC_CANGIF_EPIF; + rx_state = rec >= tec ? CAN_STATE_ERROR_PASSIVE : 0; + tx_state = rec <= tec ? CAN_STATE_ERROR_PASSIVE : 0; + netdev_dbg(priv->ndev, "Error passive interrupt\n"); + ti_hecc_change_state(ndev, rx_state, tx_state); + } + + if (int_status & HECC_CANGIF_BOIF) { + handled |= HECC_CANGIF_BOIF; + rx_state = CAN_STATE_BUS_OFF; + tx_state = CAN_STATE_BUS_OFF; + netdev_dbg(priv->ndev, "Bus off interrupt\n"); + + /* Disable all interrupts */ + hecc_write(priv, HECC_CANGIM, 0); + can_bus_off(ndev); + ti_hecc_change_state(ndev, rx_state, tx_state); + } + } else if (unlikely(priv->can.state != CAN_STATE_ERROR_ACTIVE)) { + enum can_state new_state, tx_state, rx_state; + u32 rec = hecc_read(priv, HECC_CANREC); + u32 tec = hecc_read(priv, HECC_CANTEC); + + if (rec >= 128 || tec >= 128) + new_state = CAN_STATE_ERROR_PASSIVE; + else if (rec >= 96 || tec >= 96) + new_state = CAN_STATE_ERROR_WARNING; + else + new_state = CAN_STATE_ERROR_ACTIVE; + + if (new_state < priv->can.state) { + rx_state = rec >= tec ? new_state : 0; + tx_state = rec <= tec ? new_state : 0; + ti_hecc_change_state(ndev, rx_state, tx_state); + } + } + + if (int_status & HECC_CANGIF_GMIF) { + while (priv->tx_tail - priv->tx_head > 0) { + mbxno = get_tx_tail_mb(priv); + mbx_mask = BIT(mbxno); + if (!(mbx_mask & hecc_read(priv, HECC_CANTA))) + break; + hecc_write(priv, HECC_CANTA, mbx_mask); + spin_lock_irqsave(&priv->mbx_lock, flags); + hecc_clear_bit(priv, HECC_CANME, mbx_mask); + spin_unlock_irqrestore(&priv->mbx_lock, flags); + stamp = hecc_read_stamp(priv, mbxno); + stats->tx_bytes += + can_rx_offload_get_echo_skb_queue_timestamp(&priv->offload, + mbxno, stamp, NULL); + stats->tx_packets++; + --priv->tx_tail; + } + + /* restart queue if wrap-up or if queue stalled on last pkt */ + if ((priv->tx_head == priv->tx_tail && + ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) || + (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) && + ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK))) + netif_wake_queue(ndev); + + /* offload RX mailboxes and let NAPI deliver them */ + while ((rx_pending = hecc_read(priv, HECC_CANRMP))) { + can_rx_offload_irq_offload_timestamp(&priv->offload, + rx_pending); + } + } + + /* clear all interrupt conditions - read back to avoid spurious ints */ + if (priv->use_hecc1int) { + hecc_write(priv, HECC_CANGIF1, handled); + int_status = hecc_read(priv, HECC_CANGIF1); + } else { + hecc_write(priv, HECC_CANGIF0, handled); + int_status = hecc_read(priv, HECC_CANGIF0); + } + + can_rx_offload_irq_finish(&priv->offload); + + return IRQ_HANDLED; +} + +static int ti_hecc_open(struct net_device *ndev) +{ + struct ti_hecc_priv *priv = netdev_priv(ndev); + int err; + + err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED, + ndev->name, ndev); + if (err) { + netdev_err(ndev, "error requesting interrupt\n"); + return err; + } + + ti_hecc_transceiver_switch(priv, 1); + + /* Open common can device */ + err = open_candev(ndev); + if (err) { + netdev_err(ndev, "open_candev() failed %d\n", err); + ti_hecc_transceiver_switch(priv, 0); + free_irq(ndev->irq, ndev); + return err; + } + + ti_hecc_start(ndev); + can_rx_offload_enable(&priv->offload); + netif_start_queue(ndev); + + return 0; +} + +static int ti_hecc_close(struct net_device *ndev) +{ + struct ti_hecc_priv *priv = netdev_priv(ndev); + + netif_stop_queue(ndev); + can_rx_offload_disable(&priv->offload); + ti_hecc_stop(ndev); + free_irq(ndev->irq, ndev); + close_candev(ndev); + ti_hecc_transceiver_switch(priv, 0); + + return 0; +} + +static const struct net_device_ops ti_hecc_netdev_ops = { + .ndo_open = ti_hecc_open, + .ndo_stop = ti_hecc_close, + .ndo_start_xmit = ti_hecc_xmit, + .ndo_change_mtu = can_change_mtu, +}; + +static const struct ethtool_ops ti_hecc_ethtool_ops = { + .get_ts_info = ethtool_op_get_ts_info, +}; + +static const struct of_device_id ti_hecc_dt_ids[] = { + { + .compatible = "ti,am3517-hecc", + }, + { } +}; +MODULE_DEVICE_TABLE(of, ti_hecc_dt_ids); + +static int ti_hecc_probe(struct platform_device *pdev) +{ + struct net_device *ndev = (struct net_device *)0; + struct ti_hecc_priv *priv; + struct device_node *np = pdev->dev.of_node; + struct regulator *reg_xceiver; + int err = -ENODEV; + + if (!IS_ENABLED(CONFIG_OF) || !np) + return -EINVAL; + + reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver"); + if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER) + return -EPROBE_DEFER; + else if (IS_ERR(reg_xceiver)) + reg_xceiver = NULL; + + ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX); + if (!ndev) { + dev_err(&pdev->dev, "alloc_candev failed\n"); + return -ENOMEM; + } + priv = netdev_priv(ndev); + + /* handle hecc memory */ + priv->base = devm_platform_ioremap_resource_byname(pdev, "hecc"); + if (IS_ERR(priv->base)) { + dev_err(&pdev->dev, "hecc ioremap failed\n"); + err = PTR_ERR(priv->base); + goto probe_exit_candev; + } + + /* handle hecc-ram memory */ + priv->hecc_ram = devm_platform_ioremap_resource_byname(pdev, + "hecc-ram"); + if (IS_ERR(priv->hecc_ram)) { + dev_err(&pdev->dev, "hecc-ram ioremap failed\n"); + err = PTR_ERR(priv->hecc_ram); + goto probe_exit_candev; + } + + /* handle mbx memory */ + priv->mbx = devm_platform_ioremap_resource_byname(pdev, "mbx"); + if (IS_ERR(priv->mbx)) { + dev_err(&pdev->dev, "mbx ioremap failed\n"); + err = PTR_ERR(priv->mbx); + goto probe_exit_candev; + } + + ndev->irq = platform_get_irq(pdev, 0); + if (ndev->irq < 0) { + err = ndev->irq; + goto probe_exit_candev; + } + + priv->ndev = ndev; + priv->reg_xceiver = reg_xceiver; + priv->use_hecc1int = of_property_read_bool(np, "ti,use-hecc1int"); + + priv->can.bittiming_const = &ti_hecc_bittiming_const; + priv->can.do_set_mode = ti_hecc_do_set_mode; + priv->can.do_get_berr_counter = ti_hecc_get_berr_counter; + priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; + + spin_lock_init(&priv->mbx_lock); + ndev->flags |= IFF_ECHO; + platform_set_drvdata(pdev, ndev); + SET_NETDEV_DEV(ndev, &pdev->dev); + ndev->netdev_ops = &ti_hecc_netdev_ops; + ndev->ethtool_ops = &ti_hecc_ethtool_ops; + + priv->clk = clk_get(&pdev->dev, "hecc_ck"); + if (IS_ERR(priv->clk)) { + dev_err(&pdev->dev, "No clock available\n"); + err = PTR_ERR(priv->clk); + priv->clk = NULL; + goto probe_exit_candev; + } + priv->can.clock.freq = clk_get_rate(priv->clk); + + err = clk_prepare_enable(priv->clk); + if (err) { + dev_err(&pdev->dev, "clk_prepare_enable() failed\n"); + goto probe_exit_release_clk; + } + + priv->offload.mailbox_read = ti_hecc_mailbox_read; + priv->offload.mb_first = HECC_RX_FIRST_MBOX; + priv->offload.mb_last = HECC_RX_LAST_MBOX; + err = can_rx_offload_add_timestamp(ndev, &priv->offload); + if (err) { + dev_err(&pdev->dev, "can_rx_offload_add_timestamp() failed\n"); + goto probe_exit_disable_clk; + } + + err = register_candev(ndev); + if (err) { + dev_err(&pdev->dev, "register_candev() failed\n"); + goto probe_exit_offload; + } + + dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n", + priv->base, (u32)ndev->irq); + + return 0; + +probe_exit_offload: + can_rx_offload_del(&priv->offload); +probe_exit_disable_clk: + clk_disable_unprepare(priv->clk); +probe_exit_release_clk: + clk_put(priv->clk); +probe_exit_candev: + free_candev(ndev); + + return err; +} + +static void ti_hecc_remove(struct platform_device *pdev) +{ + struct net_device *ndev = platform_get_drvdata(pdev); + struct ti_hecc_priv *priv = netdev_priv(ndev); + + unregister_candev(ndev); + clk_disable_unprepare(priv->clk); + clk_put(priv->clk); + can_rx_offload_del(&priv->offload); + free_candev(ndev); +} + +#ifdef CONFIG_PM +static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct net_device *dev = platform_get_drvdata(pdev); + struct ti_hecc_priv *priv = netdev_priv(dev); + + if (netif_running(dev)) { + netif_stop_queue(dev); + netif_device_detach(dev); + } + + hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR); + priv->can.state = CAN_STATE_SLEEPING; + + clk_disable_unprepare(priv->clk); + + return 0; +} + +static int ti_hecc_resume(struct platform_device *pdev) +{ + struct net_device *dev = platform_get_drvdata(pdev); + struct ti_hecc_priv *priv = netdev_priv(dev); + int err; + + err = clk_prepare_enable(priv->clk); + if (err) + return err; + + hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR); + priv->can.state = CAN_STATE_ERROR_ACTIVE; + + if (netif_running(dev)) { + netif_device_attach(dev); + netif_start_queue(dev); + } + + return 0; +} +#else +#define ti_hecc_suspend NULL +#define ti_hecc_resume NULL +#endif + +/* TI HECC netdevice driver: platform driver structure */ +static struct platform_driver ti_hecc_driver = { + .driver = { + .name = DRV_NAME, + .of_match_table = ti_hecc_dt_ids, + }, + .probe = ti_hecc_probe, + .remove_new = ti_hecc_remove, + .suspend = ti_hecc_suspend, + .resume = ti_hecc_resume, +}; + +module_platform_driver(ti_hecc_driver); + +MODULE_AUTHOR("Anant Gole <anantgole@ti.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION(DRV_DESC); +MODULE_ALIAS("platform:" DRV_NAME); |