diff options
Diffstat (limited to 'drivers/net/can/ti_hecc.c')
| -rw-r--r-- | drivers/net/can/ti_hecc.c | 993 |
1 files changed, 993 insertions, 0 deletions
diff --git a/drivers/net/can/ti_hecc.c b/drivers/net/can/ti_hecc.c new file mode 100644 index 000000000000..07e8016b17ec --- /dev/null +++ b/drivers/net/can/ti_hecc.c @@ -0,0 +1,993 @@ +/* + * 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/ + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed as is WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +/* + * Your platform definitions should specify module ram offsets and interrupt + * number to use as follows: + * + * static struct ti_hecc_platform_data am3517_evm_hecc_pdata = { + * .scc_hecc_offset = 0, + * .scc_ram_offset = 0x3000, + * .hecc_ram_offset = 0x3000, + * .mbx_offset = 0x2000, + * .int_line = 0, + * .revision = 1, + * }; + * + * Please see include/can/platform/ti_hecc.h for description of above fields + * + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/interrupt.h> +#include <linux/errno.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/platform_device.h> +#include <linux/clk.h> + +#include <linux/can.h> +#include <linux/can/dev.h> +#include <linux/can/error.h> +#include <linux/can/platform/ti_hecc.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) +#define HECC_TX_MBOX_MASK (~(BIT(HECC_MAX_TX_MBOX) - 1)) +#define HECC_DEF_NAPI_WEIGHT HECC_MAX_RX_MBOX + +/* + * Important Note: RX mailbox configuration + * RX mailboxes are further logically split into two - main and buffer + * mailboxes. The goal is to get all packets into main mailboxes as + * driven by mailbox number and receive priority (higher to lower) and + * buffer mailboxes are used to receive pkts while main mailboxes are being + * processed. This ensures in-order packet reception. + * + * Here are the recommended values for buffer mailbox. Note that RX mailboxes + * start after TX mailboxes: + * + * HECC_MAX_RX_MBOX HECC_RX_BUFFER_MBOX No of buffer mailboxes + * 28 12 8 + * 16 20 4 + */ + +#define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX) +#define HECC_RX_BUFFER_MBOX 12 /* as per table above */ +#define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1) +#define HECC_RX_HIGH_MBOX_MASK (~(BIT(HECC_RX_BUFFER_MBOX) - 1)) + +/* 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 /* Remote 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 */ + +/* 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_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 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 napi_struct napi; + struct net_device *ndev; + struct clk *clk; + void __iomem *base; + u32 scc_ram_offset; + u32 hecc_ram_offset; + u32 mbx_offset; + u32 int_line; + spinlock_t mbx_lock; /* CANME register needs protection */ + u32 tx_head; + u32 tx_tail; + u32 rx_next; +}; + +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->base + priv->hecc_ram_offset + mbxno * 4); +} + +static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno, + u32 reg, u32 val) +{ + __raw_writel(val, priv->base + priv->mbx_offset + mbxno * 0x10 + + reg); +} + +static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg) +{ + return __raw_readl(priv->base + priv->mbx_offset + 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_get_state(const struct net_device *ndev, + enum can_state *state) +{ + struct ti_hecc_priv *priv = netdev_priv(ndev); + + *state = priv->can.state; + return 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 + dev_warn(priv->ndev->dev.parent, "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); + dev_info(priv->ndev->dev.parent, "setting CANBTC=%#x\n", can_btc); + + return 0; +} + +static void ti_hecc_reset(struct net_device *ndev) +{ + u32 cnt; + struct ti_hecc_priv *priv = netdev_priv(ndev); + + dev_dbg(ndev->dev.parent, "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 = priv->tx_tail = HECC_TX_MASK; + priv->rx_next = HECC_RX_FIRST_MBOX; + + /* 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); + } + + /* Prevent message over-write & Enable interrupts */ + hecc_write(priv, HECC_CANOPC, HECC_SET_REG); + if (priv->int_line) { + 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 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; +} + +/* + * ti_hecc_xmit: HECC Transmit + * + * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the + * priority of the mailbox for tranmission 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; + + 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); + dev_err(priv->ndev->dev.parent, + "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 = min_t(u8, cf->can_dlc, 8); + if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */ + data |= HECC_CANMCF_RTR; + data |= get_tx_head_prio(priv) << 8; + 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(*(u32 *)(cf->data))); + if (cf->can_dlc > 4) + hecc_write_mbx(priv, mbxno, HECC_CANMDH, + be32_to_cpu(*(u32 *)(cf->data + 4))); + else + *(u32 *)(cf->data + 4) = 0; + can_put_echo_skb(skb, ndev, mbxno); + + 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_clear_bit(priv, HECC_CANMD, mbx_mask); + hecc_set_bit(priv, HECC_CANMIM, mbx_mask); + hecc_write(priv, HECC_CANTRS, mbx_mask); + + return NETDEV_TX_OK; +} + +static int ti_hecc_rx_pkt(struct ti_hecc_priv *priv, int mbxno) +{ + struct net_device_stats *stats = &priv->ndev->stats; + struct can_frame *cf; + struct sk_buff *skb; + u32 data, mbx_mask; + unsigned long flags; + + skb = alloc_can_skb(priv->ndev, &cf); + if (!skb) { + if (printk_ratelimit()) + dev_err(priv->ndev->dev.parent, + "ti_hecc_rx_pkt: alloc_can_skb() failed\n"); + return -ENOMEM; + } + + mbx_mask = BIT(mbxno); + 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->can_dlc = data & 0xF; + data = hecc_read_mbx(priv, mbxno, HECC_CANMDL); + *(u32 *)(cf->data) = cpu_to_be32(data); + if (cf->can_dlc > 4) { + data = hecc_read_mbx(priv, mbxno, HECC_CANMDH); + *(u32 *)(cf->data + 4) = cpu_to_be32(data); + } else { + *(u32 *)(cf->data + 4) = 0; + } + spin_lock_irqsave(&priv->mbx_lock, flags); + hecc_clear_bit(priv, HECC_CANME, mbx_mask); + hecc_write(priv, HECC_CANRMP, mbx_mask); + /* enable mailbox only if it is part of rx buffer mailboxes */ + if (priv->rx_next < HECC_RX_BUFFER_MBOX) + hecc_set_bit(priv, HECC_CANME, mbx_mask); + spin_unlock_irqrestore(&priv->mbx_lock, flags); + + stats->rx_bytes += cf->can_dlc; + netif_receive_skb(skb); + stats->rx_packets++; + + return 0; +} + +/* + * ti_hecc_rx_poll - HECC receive pkts + * + * The receive mailboxes start from highest numbered mailbox till last xmit + * mailbox. On CAN frame reception the hardware places the data into highest + * numbered mailbox that matches the CAN ID filter. Since all receive mailboxes + * have same filtering (ALL CAN frames) packets will arrive in the highest + * available RX mailbox and we need to ensure in-order packet reception. + * + * To ensure the packets are received in the right order we logically divide + * the RX mailboxes into main and buffer mailboxes. Packets are received as per + * mailbox priotity (higher to lower) in the main bank and once it is full we + * disable further reception into main mailboxes. While the main mailboxes are + * processed in NAPI, further packets are received in buffer mailboxes. + * + * We maintain a RX next mailbox counter to process packets and once all main + * mailboxe packets are passed to the upper stack we enable all of them but + * continue to process packets received in buffer mailboxes. With each packet + * received from buffer mailbox we enable it immediately so as to handle the + * overflow from higher mailboxes. + */ +static int ti_hecc_rx_poll(struct napi_struct *napi, int quota) +{ + struct net_device *ndev = napi->dev; + struct ti_hecc_priv *priv = netdev_priv(ndev); + u32 num_pkts = 0; + u32 mbx_mask; + unsigned long pending_pkts, flags; + + if (!netif_running(ndev)) + return 0; + + while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) && + num_pkts < quota) { + mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */ + if (mbx_mask & pending_pkts) { + if (ti_hecc_rx_pkt(priv, priv->rx_next) < 0) + return num_pkts; + ++num_pkts; + } else if (priv->rx_next > HECC_RX_BUFFER_MBOX) { + break; /* pkt not received yet */ + } + --priv->rx_next; + if (priv->rx_next == HECC_RX_BUFFER_MBOX) { + /* enable high bank mailboxes */ + spin_lock_irqsave(&priv->mbx_lock, flags); + mbx_mask = hecc_read(priv, HECC_CANME); + mbx_mask |= HECC_RX_HIGH_MBOX_MASK; + hecc_write(priv, HECC_CANME, mbx_mask); + spin_unlock_irqrestore(&priv->mbx_lock, flags); + } else if (priv->rx_next == HECC_MAX_TX_MBOX - 1) { + priv->rx_next = HECC_RX_FIRST_MBOX; + break; + } + } + + /* Enable packet interrupt if all pkts are handled */ + if (hecc_read(priv, HECC_CANRMP) == 0) { + napi_complete(napi); + /* Re-enable RX mailbox interrupts */ + mbx_mask = hecc_read(priv, HECC_CANMIM); + mbx_mask |= HECC_TX_MBOX_MASK; + hecc_write(priv, HECC_CANMIM, mbx_mask); + } + + return num_pkts; +} + +static int ti_hecc_error(struct net_device *ndev, int int_status, + int err_status) +{ + struct ti_hecc_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + struct can_frame *cf; + struct sk_buff *skb; + + /* propogate the error condition to the can stack */ + skb = alloc_can_err_skb(ndev, &cf); + if (!skb) { + if (printk_ratelimit()) + dev_err(priv->ndev->dev.parent, + "ti_hecc_error: alloc_can_err_skb() failed\n"); + return -ENOMEM; + } + + if (int_status & HECC_CANGIF_WLIF) { /* warning level int */ + if ((int_status & HECC_CANGIF_BOIF) == 0) { + priv->can.state = CAN_STATE_ERROR_WARNING; + ++priv->can.can_stats.error_warning; + cf->can_id |= CAN_ERR_CRTL; + if (hecc_read(priv, HECC_CANTEC) > 96) + cf->data[1] |= CAN_ERR_CRTL_TX_WARNING; + if (hecc_read(priv, HECC_CANREC) > 96) + cf->data[1] |= CAN_ERR_CRTL_RX_WARNING; + } + hecc_set_bit(priv, HECC_CANES, HECC_CANES_EW); + dev_dbg(priv->ndev->dev.parent, "Error Warning interrupt\n"); + hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR); + } + + if (int_status & HECC_CANGIF_EPIF) { /* error passive int */ + if ((int_status & HECC_CANGIF_BOIF) == 0) { + priv->can.state = CAN_STATE_ERROR_PASSIVE; + ++priv->can.can_stats.error_passive; + cf->can_id |= CAN_ERR_CRTL; + if (hecc_read(priv, HECC_CANTEC) > 127) + cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE; + if (hecc_read(priv, HECC_CANREC) > 127) + cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE; + } + hecc_set_bit(priv, HECC_CANES, HECC_CANES_EP); + dev_dbg(priv->ndev->dev.parent, "Error passive interrupt\n"); + hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR); + } + + /* + * Need to check busoff condition in error status register too to + * ensure warning interrupts don't hog the system + */ + if ((int_status & HECC_CANGIF_BOIF) || (err_status & HECC_CANES_BO)) { + priv->can.state = CAN_STATE_BUS_OFF; + cf->can_id |= CAN_ERR_BUSOFF; + hecc_set_bit(priv, HECC_CANES, HECC_CANES_BO); + hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR); + /* Disable all interrupts in bus-off to avoid int hog */ + hecc_write(priv, HECC_CANGIM, 0); + can_bus_off(ndev); + } + + if (err_status & HECC_BUS_ERROR) { + ++priv->can.can_stats.bus_error; + cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT; + cf->data[2] |= CAN_ERR_PROT_UNSPEC; + if (err_status & HECC_CANES_FE) { + hecc_set_bit(priv, HECC_CANES, HECC_CANES_FE); + cf->data[2] |= CAN_ERR_PROT_FORM; + } + if (err_status & HECC_CANES_BE) { + hecc_set_bit(priv, HECC_CANES, HECC_CANES_BE); + cf->data[2] |= CAN_ERR_PROT_BIT; + } + if (err_status & HECC_CANES_SE) { + hecc_set_bit(priv, HECC_CANES, HECC_CANES_SE); + cf->data[2] |= CAN_ERR_PROT_STUFF; + } + if (err_status & HECC_CANES_CRCE) { + hecc_set_bit(priv, HECC_CANES, HECC_CANES_CRCE); + cf->data[2] |= CAN_ERR_PROT_LOC_CRC_SEQ | + CAN_ERR_PROT_LOC_CRC_DEL; + } + if (err_status & HECC_CANES_ACKE) { + hecc_set_bit(priv, HECC_CANES, HECC_CANES_ACKE); + cf->data[2] |= CAN_ERR_PROT_LOC_ACK | + CAN_ERR_PROT_LOC_ACK_DEL; + } + } + + netif_receive_skb(skb); + stats->rx_packets++; + stats->rx_bytes += cf->can_dlc; + return 0; +} + +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; + unsigned long ack, flags; + + int_status = hecc_read(priv, + (priv->int_line) ? HECC_CANGIF1 : HECC_CANGIF0); + + if (!int_status) + return IRQ_NONE; + + err_status = hecc_read(priv, HECC_CANES); + if (err_status & (HECC_BUS_ERROR | HECC_CANES_BO | + HECC_CANES_EP | HECC_CANES_EW)) + ti_hecc_error(ndev, int_status, err_status); + + 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_clear_bit(priv, HECC_CANMIM, mbx_mask); + 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); + stats->tx_bytes += hecc_read_mbx(priv, mbxno, + HECC_CANMCF) & 0xF; + stats->tx_packets++; + can_get_echo_skb(ndev, mbxno); + --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); + + /* Disable RX mailbox interrupts and let NAPI reenable them */ + if (hecc_read(priv, HECC_CANRMP)) { + ack = hecc_read(priv, HECC_CANMIM); + ack &= BIT(HECC_MAX_TX_MBOX) - 1; + hecc_write(priv, HECC_CANMIM, ack); + napi_schedule(&priv->napi); + } + } + + /* clear all interrupt conditions - read back to avoid spurious ints */ + if (priv->int_line) { + hecc_write(priv, HECC_CANGIF1, HECC_SET_REG); + int_status = hecc_read(priv, HECC_CANGIF1); + } else { + hecc_write(priv, HECC_CANGIF0, HECC_SET_REG); + int_status = hecc_read(priv, HECC_CANGIF0); + } + + 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) { + dev_err(ndev->dev.parent, "error requesting interrupt\n"); + return err; + } + + /* Open common can device */ + err = open_candev(ndev); + if (err) { + dev_err(ndev->dev.parent, "open_candev() failed %d\n", err); + free_irq(ndev->irq, ndev); + return err; + } + + clk_enable(priv->clk); + ti_hecc_start(ndev); + napi_enable(&priv->napi); + 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); + napi_disable(&priv->napi); + ti_hecc_stop(ndev); + free_irq(ndev->irq, ndev); + clk_disable(priv->clk); + close_candev(ndev); + + 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, +}; + +static int ti_hecc_probe(struct platform_device *pdev) +{ + struct net_device *ndev = (struct net_device *)0; + struct ti_hecc_priv *priv; + struct ti_hecc_platform_data *pdata; + struct resource *mem, *irq; + void __iomem *addr; + int err = -ENODEV; + + pdata = pdev->dev.platform_data; + if (!pdata) { + dev_err(&pdev->dev, "No platform data\n"); + goto probe_exit; + } + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem) { + dev_err(&pdev->dev, "No mem resources\n"); + goto probe_exit; + } + irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!irq) { + dev_err(&pdev->dev, "No irq resource\n"); + goto probe_exit; + } + if (!request_mem_region(mem->start, resource_size(mem), pdev->name)) { + dev_err(&pdev->dev, "HECC region already claimed\n"); + err = -EBUSY; + goto probe_exit; + } + addr = ioremap(mem->start, resource_size(mem)); + if (!addr) { + dev_err(&pdev->dev, "ioremap failed\n"); + err = -ENOMEM; + goto probe_exit_free_region; + } + + ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX); + if (!ndev) { + dev_err(&pdev->dev, "alloc_candev failed\n"); + err = -ENOMEM; + goto probe_exit_iounmap; + } + + priv = netdev_priv(ndev); + priv->ndev = ndev; + priv->base = addr; + priv->scc_ram_offset = pdata->scc_ram_offset; + priv->hecc_ram_offset = pdata->hecc_ram_offset; + priv->mbx_offset = pdata->mbx_offset; + priv->int_line = pdata->int_line; + + priv->can.bittiming_const = &ti_hecc_bittiming_const; + priv->can.do_set_mode = ti_hecc_do_set_mode; + priv->can.do_get_state = ti_hecc_get_state; + + ndev->irq = irq->start; + ndev->flags |= IFF_ECHO; + platform_set_drvdata(pdev, ndev); + SET_NETDEV_DEV(ndev, &pdev->dev); + ndev->netdev_ops = &ti_hecc_netdev_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); + netif_napi_add(ndev, &priv->napi, ti_hecc_rx_poll, + HECC_DEF_NAPI_WEIGHT); + + err = register_candev(ndev); + if (err) { + dev_err(&pdev->dev, "register_candev() failed\n"); + goto probe_exit_clk; + } + dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n", + priv->base, (u32) ndev->irq); + + return 0; + +probe_exit_clk: + clk_put(priv->clk); +probe_exit_candev: + free_candev(ndev); +probe_exit_iounmap: + iounmap(addr); +probe_exit_free_region: + release_mem_region(mem->start, resource_size(mem)); +probe_exit: + return err; +} + +static int __devexit ti_hecc_remove(struct platform_device *pdev) +{ + struct resource *res; + struct net_device *ndev = platform_get_drvdata(pdev); + struct ti_hecc_priv *priv = netdev_priv(ndev); + + clk_put(priv->clk); + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + iounmap(priv->base); + release_mem_region(res->start, resource_size(res)); + unregister_candev(ndev); + free_candev(ndev); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +/* TI HECC netdevice driver: platform driver structure */ +static struct platform_driver ti_hecc_driver = { + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, + .probe = ti_hecc_probe, + .remove = __devexit_p(ti_hecc_remove), +}; + +static int __init ti_hecc_init_driver(void) +{ + printk(KERN_INFO DRV_DESC "\n"); + return platform_driver_register(&ti_hecc_driver); +} +module_init(ti_hecc_init_driver); + +static void __exit ti_hecc_exit_driver(void) +{ + printk(KERN_INFO DRV_DESC " unloaded\n"); + platform_driver_unregister(&ti_hecc_driver); +} +module_exit(ti_hecc_exit_driver); + +MODULE_AUTHOR("Anant Gole <anantgole@ti.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION(DRV_DESC); |