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Diffstat (limited to '')
| -rw-r--r-- | drivers/net/can/janz-ican3.c | 2062 |
1 files changed, 2062 insertions, 0 deletions
diff --git a/drivers/net/can/janz-ican3.c b/drivers/net/can/janz-ican3.c new file mode 100644 index 000000000..0732a5092 --- /dev/null +++ b/drivers/net/can/janz-ican3.c @@ -0,0 +1,2062 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Janz MODULbus VMOD-ICAN3 CAN Interface Driver + * + * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/ethtool.h> +#include <linux/platform_device.h> + +#include <linux/netdevice.h> +#include <linux/can.h> +#include <linux/can/dev.h> +#include <linux/can/skb.h> +#include <linux/can/error.h> + +#include <linux/mfd/janz.h> +#include <asm/io.h> + +/* the DPM has 64k of memory, organized into 256x 256 byte pages */ +#define DPM_NUM_PAGES 256 +#define DPM_PAGE_SIZE 256 +#define DPM_PAGE_ADDR(p) ((p) * DPM_PAGE_SIZE) + +/* JANZ ICAN3 "old-style" host interface queue page numbers */ +#define QUEUE_OLD_CONTROL 0 +#define QUEUE_OLD_RB0 1 +#define QUEUE_OLD_RB1 2 +#define QUEUE_OLD_WB0 3 +#define QUEUE_OLD_WB1 4 + +/* Janz ICAN3 "old-style" host interface control registers */ +#define MSYNC_PEER 0x00 /* ICAN only */ +#define MSYNC_LOCL 0x01 /* host only */ +#define TARGET_RUNNING 0x02 +#define FIRMWARE_STAMP 0x60 /* big endian firmware stamp */ + +#define MSYNC_RB0 0x01 +#define MSYNC_RB1 0x02 +#define MSYNC_RBLW 0x04 +#define MSYNC_RB_MASK (MSYNC_RB0 | MSYNC_RB1) + +#define MSYNC_WB0 0x10 +#define MSYNC_WB1 0x20 +#define MSYNC_WBLW 0x40 +#define MSYNC_WB_MASK (MSYNC_WB0 | MSYNC_WB1) + +/* Janz ICAN3 "new-style" host interface queue page numbers */ +#define QUEUE_TOHOST 5 +#define QUEUE_FROMHOST_MID 6 +#define QUEUE_FROMHOST_HIGH 7 +#define QUEUE_FROMHOST_LOW 8 + +/* The first free page in the DPM is #9 */ +#define DPM_FREE_START 9 + +/* Janz ICAN3 "new-style" and "fast" host interface descriptor flags */ +#define DESC_VALID 0x80 +#define DESC_WRAP 0x40 +#define DESC_INTERRUPT 0x20 +#define DESC_IVALID 0x10 +#define DESC_LEN(len) (len) + +/* Janz ICAN3 Firmware Messages */ +#define MSG_CONNECTI 0x02 +#define MSG_DISCONNECT 0x03 +#define MSG_IDVERS 0x04 +#define MSG_MSGLOST 0x05 +#define MSG_NEWHOSTIF 0x08 +#define MSG_INQUIRY 0x0a +#define MSG_SETAFILMASK 0x10 +#define MSG_INITFDPMQUEUE 0x11 +#define MSG_HWCONF 0x12 +#define MSG_FMSGLOST 0x15 +#define MSG_CEVTIND 0x37 +#define MSG_CBTRREQ 0x41 +#define MSG_COFFREQ 0x42 +#define MSG_CONREQ 0x43 +#define MSG_CCONFREQ 0x47 +#define MSG_NMTS 0xb0 +#define MSG_LMTS 0xb4 + +/* + * Janz ICAN3 CAN Inquiry Message Types + * + * NOTE: there appears to be a firmware bug here. You must send + * NOTE: INQUIRY_STATUS and expect to receive an INQUIRY_EXTENDED + * NOTE: response. The controller never responds to a message with + * NOTE: the INQUIRY_EXTENDED subspec :( + */ +#define INQUIRY_STATUS 0x00 +#define INQUIRY_TERMINATION 0x01 +#define INQUIRY_EXTENDED 0x04 + +/* Janz ICAN3 CAN Set Acceptance Filter Mask Message Types */ +#define SETAFILMASK_REJECT 0x00 +#define SETAFILMASK_FASTIF 0x02 + +/* Janz ICAN3 CAN Hardware Configuration Message Types */ +#define HWCONF_TERMINATE_ON 0x01 +#define HWCONF_TERMINATE_OFF 0x00 + +/* Janz ICAN3 CAN Event Indication Message Types */ +#define CEVTIND_EI 0x01 +#define CEVTIND_DOI 0x02 +#define CEVTIND_LOST 0x04 +#define CEVTIND_FULL 0x08 +#define CEVTIND_BEI 0x10 + +#define CEVTIND_CHIP_SJA1000 0x02 + +#define ICAN3_BUSERR_QUOTA_MAX 255 + +/* Janz ICAN3 CAN Frame Conversion */ +#define ICAN3_SNGL 0x02 +#define ICAN3_ECHO 0x10 +#define ICAN3_EFF_RTR 0x40 +#define ICAN3_SFF_RTR 0x10 +#define ICAN3_EFF 0x80 + +#define ICAN3_CAN_TYPE_MASK 0x0f +#define ICAN3_CAN_TYPE_SFF 0x00 +#define ICAN3_CAN_TYPE_EFF 0x01 + +#define ICAN3_CAN_DLC_MASK 0x0f + +/* Janz ICAN3 NMTS subtypes */ +#define NMTS_CREATE_NODE_REQ 0x0 +#define NMTS_SLAVE_STATE_IND 0x8 +#define NMTS_SLAVE_EVENT_IND 0x9 + +/* Janz ICAN3 LMTS subtypes */ +#define LMTS_BUSON_REQ 0x0 +#define LMTS_BUSOFF_REQ 0x1 +#define LMTS_CAN_CONF_REQ 0x2 + +/* Janz ICAN3 NMTS Event indications */ +#define NE_LOCAL_OCCURRED 0x3 +#define NE_LOCAL_RESOLVED 0x2 +#define NE_REMOTE_OCCURRED 0xc +#define NE_REMOTE_RESOLVED 0x8 + +/* + * SJA1000 Status and Error Register Definitions + * + * Copied from drivers/net/can/sja1000/sja1000.h + */ + +/* status register content */ +#define SR_BS 0x80 +#define SR_ES 0x40 +#define SR_TS 0x20 +#define SR_RS 0x10 +#define SR_TCS 0x08 +#define SR_TBS 0x04 +#define SR_DOS 0x02 +#define SR_RBS 0x01 + +#define SR_CRIT (SR_BS|SR_ES) + +/* ECC register */ +#define ECC_SEG 0x1F +#define ECC_DIR 0x20 +#define ECC_ERR 6 +#define ECC_BIT 0x00 +#define ECC_FORM 0x40 +#define ECC_STUFF 0x80 +#define ECC_MASK 0xc0 + +/* Number of buffers for use in the "new-style" host interface */ +#define ICAN3_NEW_BUFFERS 16 + +/* Number of buffers for use in the "fast" host interface */ +#define ICAN3_TX_BUFFERS 512 +#define ICAN3_RX_BUFFERS 1024 + +/* SJA1000 Clock Input */ +#define ICAN3_CAN_CLOCK 8000000 + +/* Janz ICAN3 firmware types */ +enum ican3_fwtype { + ICAN3_FWTYPE_ICANOS, + ICAN3_FWTYPE_CAL_CANOPEN, +}; + +/* Driver Name */ +#define DRV_NAME "janz-ican3" + +/* DPM Control Registers -- starts at offset 0x100 in the MODULbus registers */ +struct ican3_dpm_control { + /* window address register */ + u8 window_address; + u8 unused1; + + /* + * Read access: clear interrupt from microcontroller + * Write access: send interrupt to microcontroller + */ + u8 interrupt; + u8 unused2; + + /* write-only: reset all hardware on the module */ + u8 hwreset; + u8 unused3; + + /* write-only: generate an interrupt to the TPU */ + u8 tpuinterrupt; +}; + +struct ican3_dev { + + /* must be the first member */ + struct can_priv can; + + /* CAN network device */ + struct net_device *ndev; + struct napi_struct napi; + + /* module number */ + unsigned int num; + + /* base address of registers and IRQ */ + struct janz_cmodio_onboard_regs __iomem *ctrl; + struct ican3_dpm_control __iomem *dpmctrl; + void __iomem *dpm; + int irq; + + /* CAN bus termination status */ + struct completion termination_comp; + bool termination_enabled; + + /* CAN bus error status registers */ + struct completion buserror_comp; + struct can_berr_counter bec; + + /* firmware type */ + enum ican3_fwtype fwtype; + char fwinfo[32]; + + /* old and new style host interface */ + unsigned int iftype; + + /* queue for echo packets */ + struct sk_buff_head echoq; + + /* + * Any function which changes the current DPM page must hold this + * lock while it is performing data accesses. This ensures that the + * function will not be preempted and end up reading data from a + * different DPM page than it expects. + */ + spinlock_t lock; + + /* new host interface */ + unsigned int rx_int; + unsigned int rx_num; + unsigned int tx_num; + + /* fast host interface */ + unsigned int fastrx_start; + unsigned int fastrx_num; + unsigned int fasttx_start; + unsigned int fasttx_num; + + /* first free DPM page */ + unsigned int free_page; +}; + +struct ican3_msg { + u8 control; + u8 spec; + __le16 len; + u8 data[252]; +}; + +struct ican3_new_desc { + u8 control; + u8 pointer; +}; + +struct ican3_fast_desc { + u8 control; + u8 command; + u8 data[14]; +}; + +/* write to the window basic address register */ +static inline void ican3_set_page(struct ican3_dev *mod, unsigned int page) +{ + BUG_ON(page >= DPM_NUM_PAGES); + iowrite8(page, &mod->dpmctrl->window_address); +} + +/* + * ICAN3 "old-style" host interface + */ + +/* + * Receive a message from the ICAN3 "old-style" firmware interface + * + * LOCKING: must hold mod->lock + * + * returns 0 on success, -ENOMEM when no message exists + */ +static int ican3_old_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg) +{ + unsigned int mbox, mbox_page; + u8 locl, peer, xord; + + /* get the MSYNC registers */ + ican3_set_page(mod, QUEUE_OLD_CONTROL); + peer = ioread8(mod->dpm + MSYNC_PEER); + locl = ioread8(mod->dpm + MSYNC_LOCL); + xord = locl ^ peer; + + if ((xord & MSYNC_RB_MASK) == 0x00) { + netdev_dbg(mod->ndev, "no mbox for reading\n"); + return -ENOMEM; + } + + /* find the first free mbox to read */ + if ((xord & MSYNC_RB_MASK) == MSYNC_RB_MASK) + mbox = (xord & MSYNC_RBLW) ? MSYNC_RB0 : MSYNC_RB1; + else + mbox = (xord & MSYNC_RB0) ? MSYNC_RB0 : MSYNC_RB1; + + /* copy the message */ + mbox_page = (mbox == MSYNC_RB0) ? QUEUE_OLD_RB0 : QUEUE_OLD_RB1; + ican3_set_page(mod, mbox_page); + memcpy_fromio(msg, mod->dpm, sizeof(*msg)); + + /* + * notify the firmware that the read buffer is available + * for it to fill again + */ + locl ^= mbox; + + ican3_set_page(mod, QUEUE_OLD_CONTROL); + iowrite8(locl, mod->dpm + MSYNC_LOCL); + return 0; +} + +/* + * Send a message through the "old-style" firmware interface + * + * LOCKING: must hold mod->lock + * + * returns 0 on success, -ENOMEM when no free space exists + */ +static int ican3_old_send_msg(struct ican3_dev *mod, struct ican3_msg *msg) +{ + unsigned int mbox, mbox_page; + u8 locl, peer, xord; + + /* get the MSYNC registers */ + ican3_set_page(mod, QUEUE_OLD_CONTROL); + peer = ioread8(mod->dpm + MSYNC_PEER); + locl = ioread8(mod->dpm + MSYNC_LOCL); + xord = locl ^ peer; + + if ((xord & MSYNC_WB_MASK) == MSYNC_WB_MASK) { + netdev_err(mod->ndev, "no mbox for writing\n"); + return -ENOMEM; + } + + /* calculate a free mbox to use */ + mbox = (xord & MSYNC_WB0) ? MSYNC_WB1 : MSYNC_WB0; + + /* copy the message to the DPM */ + mbox_page = (mbox == MSYNC_WB0) ? QUEUE_OLD_WB0 : QUEUE_OLD_WB1; + ican3_set_page(mod, mbox_page); + memcpy_toio(mod->dpm, msg, sizeof(*msg)); + + locl ^= mbox; + if (mbox == MSYNC_WB1) + locl |= MSYNC_WBLW; + + ican3_set_page(mod, QUEUE_OLD_CONTROL); + iowrite8(locl, mod->dpm + MSYNC_LOCL); + return 0; +} + +/* + * ICAN3 "new-style" Host Interface Setup + */ + +static void ican3_init_new_host_interface(struct ican3_dev *mod) +{ + struct ican3_new_desc desc; + unsigned long flags; + void __iomem *dst; + int i; + + spin_lock_irqsave(&mod->lock, flags); + + /* setup the internal datastructures for RX */ + mod->rx_num = 0; + mod->rx_int = 0; + + /* tohost queue descriptors are in page 5 */ + ican3_set_page(mod, QUEUE_TOHOST); + dst = mod->dpm; + + /* initialize the tohost (rx) queue descriptors: pages 9-24 */ + for (i = 0; i < ICAN3_NEW_BUFFERS; i++) { + desc.control = DESC_INTERRUPT | DESC_LEN(1); /* I L=1 */ + desc.pointer = mod->free_page; + + /* set wrap flag on last buffer */ + if (i == ICAN3_NEW_BUFFERS - 1) + desc.control |= DESC_WRAP; + + memcpy_toio(dst, &desc, sizeof(desc)); + dst += sizeof(desc); + mod->free_page++; + } + + /* fromhost (tx) mid queue descriptors are in page 6 */ + ican3_set_page(mod, QUEUE_FROMHOST_MID); + dst = mod->dpm; + + /* setup the internal datastructures for TX */ + mod->tx_num = 0; + + /* initialize the fromhost mid queue descriptors: pages 25-40 */ + for (i = 0; i < ICAN3_NEW_BUFFERS; i++) { + desc.control = DESC_VALID | DESC_LEN(1); /* V L=1 */ + desc.pointer = mod->free_page; + + /* set wrap flag on last buffer */ + if (i == ICAN3_NEW_BUFFERS - 1) + desc.control |= DESC_WRAP; + + memcpy_toio(dst, &desc, sizeof(desc)); + dst += sizeof(desc); + mod->free_page++; + } + + /* fromhost hi queue descriptors are in page 7 */ + ican3_set_page(mod, QUEUE_FROMHOST_HIGH); + dst = mod->dpm; + + /* initialize only a single buffer in the fromhost hi queue (unused) */ + desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */ + desc.pointer = mod->free_page; + memcpy_toio(dst, &desc, sizeof(desc)); + mod->free_page++; + + /* fromhost low queue descriptors are in page 8 */ + ican3_set_page(mod, QUEUE_FROMHOST_LOW); + dst = mod->dpm; + + /* initialize only a single buffer in the fromhost low queue (unused) */ + desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */ + desc.pointer = mod->free_page; + memcpy_toio(dst, &desc, sizeof(desc)); + mod->free_page++; + + spin_unlock_irqrestore(&mod->lock, flags); +} + +/* + * ICAN3 Fast Host Interface Setup + */ + +static void ican3_init_fast_host_interface(struct ican3_dev *mod) +{ + struct ican3_fast_desc desc; + unsigned long flags; + unsigned int addr; + void __iomem *dst; + int i; + + spin_lock_irqsave(&mod->lock, flags); + + /* save the start recv page */ + mod->fastrx_start = mod->free_page; + mod->fastrx_num = 0; + + /* build a single fast tohost queue descriptor */ + memset(&desc, 0, sizeof(desc)); + desc.control = 0x00; + desc.command = 1; + + /* build the tohost queue descriptor ring in memory */ + addr = 0; + for (i = 0; i < ICAN3_RX_BUFFERS; i++) { + + /* set the wrap bit on the last buffer */ + if (i == ICAN3_RX_BUFFERS - 1) + desc.control |= DESC_WRAP; + + /* switch to the correct page */ + ican3_set_page(mod, mod->free_page); + + /* copy the descriptor to the DPM */ + dst = mod->dpm + addr; + memcpy_toio(dst, &desc, sizeof(desc)); + addr += sizeof(desc); + + /* move to the next page if necessary */ + if (addr >= DPM_PAGE_SIZE) { + addr = 0; + mod->free_page++; + } + } + + /* make sure we page-align the next queue */ + if (addr != 0) + mod->free_page++; + + /* save the start xmit page */ + mod->fasttx_start = mod->free_page; + mod->fasttx_num = 0; + + /* build a single fast fromhost queue descriptor */ + memset(&desc, 0, sizeof(desc)); + desc.control = DESC_VALID; + desc.command = 1; + + /* build the fromhost queue descriptor ring in memory */ + addr = 0; + for (i = 0; i < ICAN3_TX_BUFFERS; i++) { + + /* set the wrap bit on the last buffer */ + if (i == ICAN3_TX_BUFFERS - 1) + desc.control |= DESC_WRAP; + + /* switch to the correct page */ + ican3_set_page(mod, mod->free_page); + + /* copy the descriptor to the DPM */ + dst = mod->dpm + addr; + memcpy_toio(dst, &desc, sizeof(desc)); + addr += sizeof(desc); + + /* move to the next page if necessary */ + if (addr >= DPM_PAGE_SIZE) { + addr = 0; + mod->free_page++; + } + } + + spin_unlock_irqrestore(&mod->lock, flags); +} + +/* + * ICAN3 "new-style" Host Interface Message Helpers + */ + +/* + * LOCKING: must hold mod->lock + */ +static int ican3_new_send_msg(struct ican3_dev *mod, struct ican3_msg *msg) +{ + struct ican3_new_desc desc; + void __iomem *desc_addr = mod->dpm + (mod->tx_num * sizeof(desc)); + + /* switch to the fromhost mid queue, and read the buffer descriptor */ + ican3_set_page(mod, QUEUE_FROMHOST_MID); + memcpy_fromio(&desc, desc_addr, sizeof(desc)); + + if (!(desc.control & DESC_VALID)) { + netdev_dbg(mod->ndev, "%s: no free buffers\n", __func__); + return -ENOMEM; + } + + /* switch to the data page, copy the data */ + ican3_set_page(mod, desc.pointer); + memcpy_toio(mod->dpm, msg, sizeof(*msg)); + + /* switch back to the descriptor, set the valid bit, write it back */ + ican3_set_page(mod, QUEUE_FROMHOST_MID); + desc.control ^= DESC_VALID; + memcpy_toio(desc_addr, &desc, sizeof(desc)); + + /* update the tx number */ + mod->tx_num = (desc.control & DESC_WRAP) ? 0 : (mod->tx_num + 1); + return 0; +} + +/* + * LOCKING: must hold mod->lock + */ +static int ican3_new_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg) +{ + struct ican3_new_desc desc; + void __iomem *desc_addr = mod->dpm + (mod->rx_num * sizeof(desc)); + + /* switch to the tohost queue, and read the buffer descriptor */ + ican3_set_page(mod, QUEUE_TOHOST); + memcpy_fromio(&desc, desc_addr, sizeof(desc)); + + if (!(desc.control & DESC_VALID)) { + netdev_dbg(mod->ndev, "%s: no buffers to recv\n", __func__); + return -ENOMEM; + } + + /* switch to the data page, copy the data */ + ican3_set_page(mod, desc.pointer); + memcpy_fromio(msg, mod->dpm, sizeof(*msg)); + + /* switch back to the descriptor, toggle the valid bit, write it back */ + ican3_set_page(mod, QUEUE_TOHOST); + desc.control ^= DESC_VALID; + memcpy_toio(desc_addr, &desc, sizeof(desc)); + + /* update the rx number */ + mod->rx_num = (desc.control & DESC_WRAP) ? 0 : (mod->rx_num + 1); + return 0; +} + +/* + * Message Send / Recv Helpers + */ + +static int ican3_send_msg(struct ican3_dev *mod, struct ican3_msg *msg) +{ + unsigned long flags; + int ret; + + spin_lock_irqsave(&mod->lock, flags); + + if (mod->iftype == 0) + ret = ican3_old_send_msg(mod, msg); + else + ret = ican3_new_send_msg(mod, msg); + + spin_unlock_irqrestore(&mod->lock, flags); + return ret; +} + +static int ican3_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg) +{ + unsigned long flags; + int ret; + + spin_lock_irqsave(&mod->lock, flags); + + if (mod->iftype == 0) + ret = ican3_old_recv_msg(mod, msg); + else + ret = ican3_new_recv_msg(mod, msg); + + spin_unlock_irqrestore(&mod->lock, flags); + return ret; +} + +/* + * Quick Pre-constructed Messages + */ + +static int ican3_msg_connect(struct ican3_dev *mod) +{ + struct ican3_msg msg; + + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_CONNECTI; + msg.len = cpu_to_le16(0); + + return ican3_send_msg(mod, &msg); +} + +static int ican3_msg_disconnect(struct ican3_dev *mod) +{ + struct ican3_msg msg; + + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_DISCONNECT; + msg.len = cpu_to_le16(0); + + return ican3_send_msg(mod, &msg); +} + +static int ican3_msg_newhostif(struct ican3_dev *mod) +{ + struct ican3_msg msg; + int ret; + + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_NEWHOSTIF; + msg.len = cpu_to_le16(0); + + /* If we're not using the old interface, switching seems bogus */ + WARN_ON(mod->iftype != 0); + + ret = ican3_send_msg(mod, &msg); + if (ret) + return ret; + + /* mark the module as using the new host interface */ + mod->iftype = 1; + return 0; +} + +static int ican3_msg_fasthostif(struct ican3_dev *mod) +{ + struct ican3_msg msg; + unsigned int addr; + + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_INITFDPMQUEUE; + msg.len = cpu_to_le16(8); + + /* write the tohost queue start address */ + addr = DPM_PAGE_ADDR(mod->fastrx_start); + msg.data[0] = addr & 0xff; + msg.data[1] = (addr >> 8) & 0xff; + msg.data[2] = (addr >> 16) & 0xff; + msg.data[3] = (addr >> 24) & 0xff; + + /* write the fromhost queue start address */ + addr = DPM_PAGE_ADDR(mod->fasttx_start); + msg.data[4] = addr & 0xff; + msg.data[5] = (addr >> 8) & 0xff; + msg.data[6] = (addr >> 16) & 0xff; + msg.data[7] = (addr >> 24) & 0xff; + + /* If we're not using the new interface yet, we cannot do this */ + WARN_ON(mod->iftype != 1); + + return ican3_send_msg(mod, &msg); +} + +/* + * Setup the CAN filter to either accept or reject all + * messages from the CAN bus. + */ +static int ican3_set_id_filter(struct ican3_dev *mod, bool accept) +{ + struct ican3_msg msg; + int ret; + + /* Standard Frame Format */ + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_SETAFILMASK; + msg.len = cpu_to_le16(5); + msg.data[0] = 0x00; /* IDLo LSB */ + msg.data[1] = 0x00; /* IDLo MSB */ + msg.data[2] = 0xff; /* IDHi LSB */ + msg.data[3] = 0x07; /* IDHi MSB */ + + /* accept all frames for fast host if, or reject all frames */ + msg.data[4] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT; + + ret = ican3_send_msg(mod, &msg); + if (ret) + return ret; + + /* Extended Frame Format */ + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_SETAFILMASK; + msg.len = cpu_to_le16(13); + msg.data[0] = 0; /* MUX = 0 */ + msg.data[1] = 0x00; /* IDLo LSB */ + msg.data[2] = 0x00; + msg.data[3] = 0x00; + msg.data[4] = 0x20; /* IDLo MSB */ + msg.data[5] = 0xff; /* IDHi LSB */ + msg.data[6] = 0xff; + msg.data[7] = 0xff; + msg.data[8] = 0x3f; /* IDHi MSB */ + + /* accept all frames for fast host if, or reject all frames */ + msg.data[9] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT; + + return ican3_send_msg(mod, &msg); +} + +/* + * Bring the CAN bus online or offline + */ +static int ican3_set_bus_state(struct ican3_dev *mod, bool on) +{ + struct can_bittiming *bt = &mod->can.bittiming; + struct ican3_msg msg; + u8 btr0, btr1; + int res; + + /* This algorithm was stolen from drivers/net/can/sja1000/sja1000.c */ + /* The bittiming register command for the ICAN3 just sets the bit timing */ + /* registers on the SJA1000 chip directly */ + btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); + btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | + (((bt->phase_seg2 - 1) & 0x7) << 4); + if (mod->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) + btr1 |= 0x80; + + if (mod->fwtype == ICAN3_FWTYPE_ICANOS) { + if (on) { + /* set bittiming */ + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_CBTRREQ; + msg.len = cpu_to_le16(4); + msg.data[0] = 0x00; + msg.data[1] = 0x00; + msg.data[2] = btr0; + msg.data[3] = btr1; + + res = ican3_send_msg(mod, &msg); + if (res) + return res; + } + + /* can-on/off request */ + memset(&msg, 0, sizeof(msg)); + msg.spec = on ? MSG_CONREQ : MSG_COFFREQ; + msg.len = cpu_to_le16(0); + + return ican3_send_msg(mod, &msg); + + } else if (mod->fwtype == ICAN3_FWTYPE_CAL_CANOPEN) { + /* bittiming + can-on/off request */ + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_LMTS; + if (on) { + msg.len = cpu_to_le16(4); + msg.data[0] = LMTS_BUSON_REQ; + msg.data[1] = 0; + msg.data[2] = btr0; + msg.data[3] = btr1; + } else { + msg.len = cpu_to_le16(2); + msg.data[0] = LMTS_BUSOFF_REQ; + msg.data[1] = 0; + } + res = ican3_send_msg(mod, &msg); + if (res) + return res; + + if (on) { + /* create NMT Slave Node for error processing + * class 2 (with error capability, see CiA/DS203-1) + * id 1 + * name locnod1 (must be exactly 7 bytes) + */ + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_NMTS; + msg.len = cpu_to_le16(11); + msg.data[0] = NMTS_CREATE_NODE_REQ; + msg.data[1] = 0; + msg.data[2] = 2; /* node class */ + msg.data[3] = 1; /* node id */ + strcpy(msg.data + 4, "locnod1"); /* node name */ + return ican3_send_msg(mod, &msg); + } + return 0; + } + return -ENOTSUPP; +} + +static int ican3_set_termination(struct ican3_dev *mod, bool on) +{ + struct ican3_msg msg; + + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_HWCONF; + msg.len = cpu_to_le16(2); + msg.data[0] = 0x00; + msg.data[1] = on ? HWCONF_TERMINATE_ON : HWCONF_TERMINATE_OFF; + + return ican3_send_msg(mod, &msg); +} + +static int ican3_send_inquiry(struct ican3_dev *mod, u8 subspec) +{ + struct ican3_msg msg; + + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_INQUIRY; + msg.len = cpu_to_le16(2); + msg.data[0] = subspec; + msg.data[1] = 0x00; + + return ican3_send_msg(mod, &msg); +} + +static int ican3_set_buserror(struct ican3_dev *mod, u8 quota) +{ + struct ican3_msg msg; + + if (mod->fwtype == ICAN3_FWTYPE_ICANOS) { + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_CCONFREQ; + msg.len = cpu_to_le16(2); + msg.data[0] = 0x00; + msg.data[1] = quota; + } else if (mod->fwtype == ICAN3_FWTYPE_CAL_CANOPEN) { + memset(&msg, 0, sizeof(msg)); + msg.spec = MSG_LMTS; + msg.len = cpu_to_le16(4); + msg.data[0] = LMTS_CAN_CONF_REQ; + msg.data[1] = 0x00; + msg.data[2] = 0x00; + msg.data[3] = quota; + } else { + return -ENOTSUPP; + } + return ican3_send_msg(mod, &msg); +} + +/* + * ICAN3 to Linux CAN Frame Conversion + */ + +static void ican3_to_can_frame(struct ican3_dev *mod, + struct ican3_fast_desc *desc, + struct can_frame *cf) +{ + if ((desc->command & ICAN3_CAN_TYPE_MASK) == ICAN3_CAN_TYPE_SFF) { + if (desc->data[1] & ICAN3_SFF_RTR) + cf->can_id |= CAN_RTR_FLAG; + + cf->can_id |= desc->data[0] << 3; + cf->can_id |= (desc->data[1] & 0xe0) >> 5; + cf->len = can_cc_dlc2len(desc->data[1] & ICAN3_CAN_DLC_MASK); + memcpy(cf->data, &desc->data[2], cf->len); + } else { + cf->len = can_cc_dlc2len(desc->data[0] & ICAN3_CAN_DLC_MASK); + if (desc->data[0] & ICAN3_EFF_RTR) + cf->can_id |= CAN_RTR_FLAG; + + if (desc->data[0] & ICAN3_EFF) { + cf->can_id |= CAN_EFF_FLAG; + cf->can_id |= desc->data[2] << 21; /* 28-21 */ + cf->can_id |= desc->data[3] << 13; /* 20-13 */ + cf->can_id |= desc->data[4] << 5; /* 12-5 */ + cf->can_id |= (desc->data[5] & 0xf8) >> 3; + } else { + cf->can_id |= desc->data[2] << 3; /* 10-3 */ + cf->can_id |= desc->data[3] >> 5; /* 2-0 */ + } + + memcpy(cf->data, &desc->data[6], cf->len); + } +} + +static void can_frame_to_ican3(struct ican3_dev *mod, + struct can_frame *cf, + struct ican3_fast_desc *desc) +{ + /* clear out any stale data in the descriptor */ + memset(desc->data, 0, sizeof(desc->data)); + + /* we always use the extended format, with the ECHO flag set */ + desc->command = ICAN3_CAN_TYPE_EFF; + desc->data[0] |= cf->len; + desc->data[1] |= ICAN3_ECHO; + + /* support single transmission (no retries) mode */ + if (mod->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT) + desc->data[1] |= ICAN3_SNGL; + + if (cf->can_id & CAN_RTR_FLAG) + desc->data[0] |= ICAN3_EFF_RTR; + + /* pack the id into the correct places */ + if (cf->can_id & CAN_EFF_FLAG) { + desc->data[0] |= ICAN3_EFF; + desc->data[2] = (cf->can_id & 0x1fe00000) >> 21; /* 28-21 */ + desc->data[3] = (cf->can_id & 0x001fe000) >> 13; /* 20-13 */ + desc->data[4] = (cf->can_id & 0x00001fe0) >> 5; /* 12-5 */ + desc->data[5] = (cf->can_id & 0x0000001f) << 3; /* 4-0 */ + } else { + desc->data[2] = (cf->can_id & 0x7F8) >> 3; /* bits 10-3 */ + desc->data[3] = (cf->can_id & 0x007) << 5; /* bits 2-0 */ + } + + /* copy the data bits into the descriptor */ + memcpy(&desc->data[6], cf->data, cf->len); +} + +/* + * Interrupt Handling + */ + +/* + * Handle an ID + Version message response from the firmware. We never generate + * this message in production code, but it is very useful when debugging to be + * able to display this message. + */ +static void ican3_handle_idvers(struct ican3_dev *mod, struct ican3_msg *msg) +{ + netdev_dbg(mod->ndev, "IDVERS response: %s\n", msg->data); +} + +static void ican3_handle_msglost(struct ican3_dev *mod, struct ican3_msg *msg) +{ + struct net_device *dev = mod->ndev; + struct net_device_stats *stats = &dev->stats; + struct can_frame *cf; + struct sk_buff *skb; + + /* + * Report that communication messages with the microcontroller firmware + * are being lost. These are never CAN frames, so we do not generate an + * error frame for userspace + */ + if (msg->spec == MSG_MSGLOST) { + netdev_err(mod->ndev, "lost %d control messages\n", msg->data[0]); + return; + } + + /* + * Oops, this indicates that we have lost messages in the fast queue, + * which are exclusively CAN messages. Our driver isn't reading CAN + * frames fast enough. + * + * We'll pretend that the SJA1000 told us that it ran out of buffer + * space, because there is not a better message for this. + */ + skb = alloc_can_err_skb(dev, &cf); + if (skb) { + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; + stats->rx_over_errors++; + stats->rx_errors++; + netif_rx(skb); + } +} + +/* + * Handle CAN Event Indication Messages from the firmware + * + * The ICAN3 firmware provides the values of some SJA1000 registers when it + * generates this message. The code below is largely copied from the + * drivers/net/can/sja1000/sja1000.c file, and adapted as necessary + */ +static int ican3_handle_cevtind(struct ican3_dev *mod, struct ican3_msg *msg) +{ + struct net_device *dev = mod->ndev; + struct net_device_stats *stats = &dev->stats; + enum can_state state = mod->can.state; + u8 isrc, ecc, status, rxerr, txerr; + struct can_frame *cf; + struct sk_buff *skb; + + /* we can only handle the SJA1000 part */ + if (msg->data[1] != CEVTIND_CHIP_SJA1000) { + netdev_err(mod->ndev, "unable to handle errors on non-SJA1000\n"); + return -ENODEV; + } + + /* check the message length for sanity */ + if (le16_to_cpu(msg->len) < 6) { + netdev_err(mod->ndev, "error message too short\n"); + return -EINVAL; + } + + isrc = msg->data[0]; + ecc = msg->data[2]; + status = msg->data[3]; + rxerr = msg->data[4]; + txerr = msg->data[5]; + + /* + * This hardware lacks any support other than bus error messages to + * determine if packet transmission has failed. + * + * When TX errors happen, one echo skb needs to be dropped from the + * front of the queue. + * + * A small bit of code is duplicated here and below, to avoid error + * skb allocation when it will just be freed immediately. + */ + if (isrc == CEVTIND_BEI) { + int ret; + netdev_dbg(mod->ndev, "bus error interrupt\n"); + + /* TX error */ + if (!(ecc & ECC_DIR)) { + kfree_skb(skb_dequeue(&mod->echoq)); + stats->tx_errors++; + } else { + stats->rx_errors++; + } + + /* + * The controller automatically disables bus-error interrupts + * and therefore we must re-enable them. + */ + ret = ican3_set_buserror(mod, 1); + if (ret) { + netdev_err(mod->ndev, "unable to re-enable bus-error\n"); + return ret; + } + + /* bus error reporting is off, return immediately */ + if (!(mod->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) + return 0; + } + + skb = alloc_can_err_skb(dev, &cf); + if (skb == NULL) + return -ENOMEM; + + /* data overrun interrupt */ + if (isrc == CEVTIND_DOI || isrc == CEVTIND_LOST) { + netdev_dbg(mod->ndev, "data overrun interrupt\n"); + cf->can_id |= CAN_ERR_CRTL; + cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; + stats->rx_over_errors++; + stats->rx_errors++; + } + + /* error warning + passive interrupt */ + if (isrc == CEVTIND_EI) { + netdev_dbg(mod->ndev, "error warning + passive interrupt\n"); + if (status & SR_BS) { + state = CAN_STATE_BUS_OFF; + cf->can_id |= CAN_ERR_BUSOFF; + mod->can.can_stats.bus_off++; + can_bus_off(dev); + } else if (status & SR_ES) { + if (rxerr >= 128 || txerr >= 128) + state = CAN_STATE_ERROR_PASSIVE; + else + state = CAN_STATE_ERROR_WARNING; + } else { + state = CAN_STATE_ERROR_ACTIVE; + } + } + + /* bus error interrupt */ + if (isrc == CEVTIND_BEI) { + mod->can.can_stats.bus_error++; + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR | CAN_ERR_CNT; + + switch (ecc & ECC_MASK) { + case ECC_BIT: + cf->data[2] |= CAN_ERR_PROT_BIT; + break; + case ECC_FORM: + cf->data[2] |= CAN_ERR_PROT_FORM; + break; + case ECC_STUFF: + cf->data[2] |= CAN_ERR_PROT_STUFF; + break; + default: + cf->data[3] = ecc & ECC_SEG; + break; + } + + if (!(ecc & ECC_DIR)) + cf->data[2] |= CAN_ERR_PROT_TX; + + cf->data[6] = txerr; + cf->data[7] = rxerr; + } + + if (state != mod->can.state && (state == CAN_STATE_ERROR_WARNING || + state == CAN_STATE_ERROR_PASSIVE)) { + cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT; + if (state == CAN_STATE_ERROR_WARNING) { + mod->can.can_stats.error_warning++; + cf->data[1] = (txerr > rxerr) ? + CAN_ERR_CRTL_TX_WARNING : + CAN_ERR_CRTL_RX_WARNING; + } else { + mod->can.can_stats.error_passive++; + cf->data[1] = (txerr > rxerr) ? + CAN_ERR_CRTL_TX_PASSIVE : + CAN_ERR_CRTL_RX_PASSIVE; + } + + cf->data[6] = txerr; + cf->data[7] = rxerr; + } + + mod->can.state = state; + netif_rx(skb); + return 0; +} + +static void ican3_handle_inquiry(struct ican3_dev *mod, struct ican3_msg *msg) +{ + switch (msg->data[0]) { + case INQUIRY_STATUS: + case INQUIRY_EXTENDED: + mod->bec.rxerr = msg->data[5]; + mod->bec.txerr = msg->data[6]; + complete(&mod->buserror_comp); + break; + case INQUIRY_TERMINATION: + mod->termination_enabled = msg->data[6] & HWCONF_TERMINATE_ON; + complete(&mod->termination_comp); + break; + default: + netdev_err(mod->ndev, "received an unknown inquiry response\n"); + break; + } +} + +/* Handle NMTS Slave Event Indication Messages from the firmware */ +static void ican3_handle_nmtsind(struct ican3_dev *mod, struct ican3_msg *msg) +{ + u16 subspec; + + subspec = msg->data[0] + msg->data[1] * 0x100; + if (subspec == NMTS_SLAVE_EVENT_IND) { + switch (msg->data[2]) { + case NE_LOCAL_OCCURRED: + case NE_LOCAL_RESOLVED: + /* now follows the same message as Raw ICANOS CEVTIND + * shift the data at the same place and call this method + */ + le16_add_cpu(&msg->len, -3); + memmove(msg->data, msg->data + 3, le16_to_cpu(msg->len)); + ican3_handle_cevtind(mod, msg); + break; + case NE_REMOTE_OCCURRED: + case NE_REMOTE_RESOLVED: + /* should not occurre, ignore */ + break; + default: + netdev_warn(mod->ndev, "unknown NMTS event indication %x\n", + msg->data[2]); + break; + } + } else if (subspec == NMTS_SLAVE_STATE_IND) { + /* ignore state indications */ + } else { + netdev_warn(mod->ndev, "unhandled NMTS indication %x\n", + subspec); + return; + } +} + +static void ican3_handle_unknown_message(struct ican3_dev *mod, + struct ican3_msg *msg) +{ + netdev_warn(mod->ndev, "received unknown message: spec 0x%.2x length %d\n", + msg->spec, le16_to_cpu(msg->len)); +} + +/* + * Handle a control message from the firmware + */ +static void ican3_handle_message(struct ican3_dev *mod, struct ican3_msg *msg) +{ + netdev_dbg(mod->ndev, "%s: modno %d spec 0x%.2x len %d bytes\n", __func__, + mod->num, msg->spec, le16_to_cpu(msg->len)); + + switch (msg->spec) { + case MSG_IDVERS: + ican3_handle_idvers(mod, msg); + break; + case MSG_MSGLOST: + case MSG_FMSGLOST: + ican3_handle_msglost(mod, msg); + break; + case MSG_CEVTIND: + ican3_handle_cevtind(mod, msg); + break; + case MSG_INQUIRY: + ican3_handle_inquiry(mod, msg); + break; + case MSG_NMTS: + ican3_handle_nmtsind(mod, msg); + break; + default: + ican3_handle_unknown_message(mod, msg); + break; + } +} + +/* + * The ican3 needs to store all echo skbs, and therefore cannot + * use the generic infrastructure for this. + */ +static void ican3_put_echo_skb(struct ican3_dev *mod, struct sk_buff *skb) +{ + skb = can_create_echo_skb(skb); + if (!skb) + return; + + skb_tx_timestamp(skb); + + /* save this skb for tx interrupt echo handling */ + skb_queue_tail(&mod->echoq, skb); +} + +static unsigned int ican3_get_echo_skb(struct ican3_dev *mod) +{ + struct sk_buff *skb = skb_dequeue(&mod->echoq); + struct can_frame *cf; + u8 dlc = 0; + + /* this should never trigger unless there is a driver bug */ + if (!skb) { + netdev_err(mod->ndev, "BUG: echo skb not occupied\n"); + return 0; + } + + cf = (struct can_frame *)skb->data; + if (!(cf->can_id & CAN_RTR_FLAG)) + dlc = cf->len; + + /* check flag whether this packet has to be looped back */ + if (skb->pkt_type != PACKET_LOOPBACK) { + kfree_skb(skb); + return dlc; + } + + skb->protocol = htons(ETH_P_CAN); + skb->pkt_type = PACKET_BROADCAST; + skb->ip_summed = CHECKSUM_UNNECESSARY; + skb->dev = mod->ndev; + netif_receive_skb(skb); + return dlc; +} + +/* + * Compare an skb with an existing echo skb + * + * This function will be used on devices which have a hardware loopback. + * On these devices, this function can be used to compare a received skb + * with the saved echo skbs so that the hardware echo skb can be dropped. + * + * Returns true if the skb's are identical, false otherwise. + */ +static bool ican3_echo_skb_matches(struct ican3_dev *mod, struct sk_buff *skb) +{ + struct can_frame *cf = (struct can_frame *)skb->data; + struct sk_buff *echo_skb = skb_peek(&mod->echoq); + struct can_frame *echo_cf; + + if (!echo_skb) + return false; + + echo_cf = (struct can_frame *)echo_skb->data; + if (cf->can_id != echo_cf->can_id) + return false; + + if (cf->len != echo_cf->len) + return false; + + return memcmp(cf->data, echo_cf->data, cf->len) == 0; +} + +/* + * Check that there is room in the TX ring to transmit another skb + * + * LOCKING: must hold mod->lock + */ +static bool ican3_txok(struct ican3_dev *mod) +{ + struct ican3_fast_desc __iomem *desc; + u8 control; + + /* check that we have echo queue space */ + if (skb_queue_len(&mod->echoq) >= ICAN3_TX_BUFFERS) + return false; + + /* copy the control bits of the descriptor */ + ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16)); + desc = mod->dpm + ((mod->fasttx_num % 16) * sizeof(*desc)); + control = ioread8(&desc->control); + + /* if the control bits are not valid, then we have no more space */ + if (!(control & DESC_VALID)) + return false; + + return true; +} + +/* + * Receive one CAN frame from the hardware + * + * CONTEXT: must be called from user context + */ +static int ican3_recv_skb(struct ican3_dev *mod) +{ + struct net_device *ndev = mod->ndev; + struct net_device_stats *stats = &ndev->stats; + struct ican3_fast_desc desc; + void __iomem *desc_addr; + struct can_frame *cf; + struct sk_buff *skb; + unsigned long flags; + + spin_lock_irqsave(&mod->lock, flags); + + /* copy the whole descriptor */ + ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16)); + desc_addr = mod->dpm + ((mod->fastrx_num % 16) * sizeof(desc)); + memcpy_fromio(&desc, desc_addr, sizeof(desc)); + + spin_unlock_irqrestore(&mod->lock, flags); + + /* check that we actually have a CAN frame */ + if (!(desc.control & DESC_VALID)) + return -ENOBUFS; + + /* allocate an skb */ + skb = alloc_can_skb(ndev, &cf); + if (unlikely(skb == NULL)) { + stats->rx_dropped++; + goto err_noalloc; + } + + /* convert the ICAN3 frame into Linux CAN format */ + ican3_to_can_frame(mod, &desc, cf); + + /* + * If this is an ECHO frame received from the hardware loopback + * feature, use the skb saved in the ECHO stack instead. This allows + * the Linux CAN core to support CAN_RAW_RECV_OWN_MSGS correctly. + * + * Since this is a confirmation of a successfully transmitted packet + * sent from this host, update the transmit statistics. + * + * Also, the netdevice queue needs to be allowed to send packets again. + */ + if (ican3_echo_skb_matches(mod, skb)) { + stats->tx_packets++; + stats->tx_bytes += ican3_get_echo_skb(mod); + kfree_skb(skb); + goto err_noalloc; + } + + /* update statistics, receive the skb */ + stats->rx_packets++; + if (!(cf->can_id & CAN_RTR_FLAG)) + stats->rx_bytes += cf->len; + netif_receive_skb(skb); + +err_noalloc: + /* toggle the valid bit and return the descriptor to the ring */ + desc.control ^= DESC_VALID; + + spin_lock_irqsave(&mod->lock, flags); + + ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16)); + memcpy_toio(desc_addr, &desc, 1); + + /* update the next buffer pointer */ + mod->fastrx_num = (desc.control & DESC_WRAP) ? 0 + : (mod->fastrx_num + 1); + + /* there are still more buffers to process */ + spin_unlock_irqrestore(&mod->lock, flags); + return 0; +} + +static int ican3_napi(struct napi_struct *napi, int budget) +{ + struct ican3_dev *mod = container_of(napi, struct ican3_dev, napi); + unsigned long flags; + int received = 0; + int ret; + + /* process all communication messages */ + while (true) { + struct ican3_msg msg; + ret = ican3_recv_msg(mod, &msg); + if (ret) + break; + + ican3_handle_message(mod, &msg); + } + + /* process all CAN frames from the fast interface */ + while (received < budget) { + ret = ican3_recv_skb(mod); + if (ret) + break; + + received++; + } + + /* We have processed all packets that the adapter had, but it + * was less than our budget, stop polling */ + if (received < budget) + napi_complete_done(napi, received); + + spin_lock_irqsave(&mod->lock, flags); + + /* Wake up the transmit queue if necessary */ + if (netif_queue_stopped(mod->ndev) && ican3_txok(mod)) + netif_wake_queue(mod->ndev); + + spin_unlock_irqrestore(&mod->lock, flags); + + /* re-enable interrupt generation */ + iowrite8(1 << mod->num, &mod->ctrl->int_enable); + return received; +} + +static irqreturn_t ican3_irq(int irq, void *dev_id) +{ + struct ican3_dev *mod = dev_id; + u8 stat; + + /* + * The interrupt status register on this device reports interrupts + * as zeroes instead of using ones like most other devices + */ + stat = ioread8(&mod->ctrl->int_disable) & (1 << mod->num); + if (stat == (1 << mod->num)) + return IRQ_NONE; + + /* clear the MODULbus interrupt from the microcontroller */ + ioread8(&mod->dpmctrl->interrupt); + + /* disable interrupt generation, schedule the NAPI poller */ + iowrite8(1 << mod->num, &mod->ctrl->int_disable); + napi_schedule(&mod->napi); + return IRQ_HANDLED; +} + +/* + * Firmware reset, startup, and shutdown + */ + +/* + * Reset an ICAN module to its power-on state + * + * CONTEXT: no network device registered + */ +static int ican3_reset_module(struct ican3_dev *mod) +{ + unsigned long start; + u8 runold, runnew; + + /* disable interrupts so no more work is scheduled */ + iowrite8(1 << mod->num, &mod->ctrl->int_disable); + + /* the first unallocated page in the DPM is #9 */ + mod->free_page = DPM_FREE_START; + + ican3_set_page(mod, QUEUE_OLD_CONTROL); + runold = ioread8(mod->dpm + TARGET_RUNNING); + + /* reset the module */ + iowrite8(0x00, &mod->dpmctrl->hwreset); + + /* wait until the module has finished resetting and is running */ + start = jiffies; + do { + ican3_set_page(mod, QUEUE_OLD_CONTROL); + runnew = ioread8(mod->dpm + TARGET_RUNNING); + if (runnew == (runold ^ 0xff)) + return 0; + + msleep(10); + } while (time_before(jiffies, start + HZ / 2)); + + netdev_err(mod->ndev, "failed to reset CAN module\n"); + return -ETIMEDOUT; +} + +static void ican3_shutdown_module(struct ican3_dev *mod) +{ + ican3_msg_disconnect(mod); + ican3_reset_module(mod); +} + +/* + * Startup an ICAN module, bringing it into fast mode + */ +static int ican3_startup_module(struct ican3_dev *mod) +{ + int ret; + + ret = ican3_reset_module(mod); + if (ret) { + netdev_err(mod->ndev, "unable to reset module\n"); + return ret; + } + + /* detect firmware */ + memcpy_fromio(mod->fwinfo, mod->dpm + FIRMWARE_STAMP, sizeof(mod->fwinfo) - 1); + if (strncmp(mod->fwinfo, "JANZ-ICAN3", 10)) { + netdev_err(mod->ndev, "ICAN3 not detected (found %s)\n", mod->fwinfo); + return -ENODEV; + } + if (strstr(mod->fwinfo, "CAL/CANopen")) + mod->fwtype = ICAN3_FWTYPE_CAL_CANOPEN; + else + mod->fwtype = ICAN3_FWTYPE_ICANOS; + + /* re-enable interrupts so we can send messages */ + iowrite8(1 << mod->num, &mod->ctrl->int_enable); + + ret = ican3_msg_connect(mod); + if (ret) { + netdev_err(mod->ndev, "unable to connect to module\n"); + return ret; + } + + ican3_init_new_host_interface(mod); + ret = ican3_msg_newhostif(mod); + if (ret) { + netdev_err(mod->ndev, "unable to switch to new-style interface\n"); + return ret; + } + + /* default to "termination on" */ + ret = ican3_set_termination(mod, true); + if (ret) { + netdev_err(mod->ndev, "unable to enable termination\n"); + return ret; + } + + /* default to "bus errors enabled" */ + ret = ican3_set_buserror(mod, 1); + if (ret) { + netdev_err(mod->ndev, "unable to set bus-error\n"); + return ret; + } + + ican3_init_fast_host_interface(mod); + ret = ican3_msg_fasthostif(mod); + if (ret) { + netdev_err(mod->ndev, "unable to switch to fast host interface\n"); + return ret; + } + + ret = ican3_set_id_filter(mod, true); + if (ret) { + netdev_err(mod->ndev, "unable to set acceptance filter\n"); + return ret; + } + + return 0; +} + +/* + * CAN Network Device + */ + +static int ican3_open(struct net_device *ndev) +{ + struct ican3_dev *mod = netdev_priv(ndev); + int ret; + + /* open the CAN layer */ + ret = open_candev(ndev); + if (ret) { + netdev_err(mod->ndev, "unable to start CAN layer\n"); + return ret; + } + + /* bring the bus online */ + ret = ican3_set_bus_state(mod, true); + if (ret) { + netdev_err(mod->ndev, "unable to set bus-on\n"); + close_candev(ndev); + return ret; + } + + /* start up the network device */ + mod->can.state = CAN_STATE_ERROR_ACTIVE; + netif_start_queue(ndev); + + return 0; +} + +static int ican3_stop(struct net_device *ndev) +{ + struct ican3_dev *mod = netdev_priv(ndev); + int ret; + + /* stop the network device xmit routine */ + netif_stop_queue(ndev); + mod->can.state = CAN_STATE_STOPPED; + + /* bring the bus offline, stop receiving packets */ + ret = ican3_set_bus_state(mod, false); + if (ret) { + netdev_err(mod->ndev, "unable to set bus-off\n"); + return ret; + } + + /* drop all outstanding echo skbs */ + skb_queue_purge(&mod->echoq); + + /* close the CAN layer */ + close_candev(ndev); + return 0; +} + +static netdev_tx_t ican3_xmit(struct sk_buff *skb, struct net_device *ndev) +{ + struct ican3_dev *mod = netdev_priv(ndev); + struct can_frame *cf = (struct can_frame *)skb->data; + struct ican3_fast_desc desc; + void __iomem *desc_addr; + unsigned long flags; + + if (can_dev_dropped_skb(ndev, skb)) + return NETDEV_TX_OK; + + spin_lock_irqsave(&mod->lock, flags); + + /* check that we can actually transmit */ + if (!ican3_txok(mod)) { + netdev_err(mod->ndev, "BUG: no free descriptors\n"); + spin_unlock_irqrestore(&mod->lock, flags); + return NETDEV_TX_BUSY; + } + + /* copy the control bits of the descriptor */ + ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16)); + desc_addr = mod->dpm + ((mod->fasttx_num % 16) * sizeof(desc)); + memset(&desc, 0, sizeof(desc)); + memcpy_fromio(&desc, desc_addr, 1); + + /* convert the Linux CAN frame into ICAN3 format */ + can_frame_to_ican3(mod, cf, &desc); + + /* + * This hardware doesn't have TX-done notifications, so we'll try and + * emulate it the best we can using ECHO skbs. Add the skb to the ECHO + * stack. Upon packet reception, check if the ECHO skb and received + * skb match, and use that to wake the queue. + */ + ican3_put_echo_skb(mod, skb); + + /* + * the programming manual says that you must set the IVALID bit, then + * interrupt, then set the valid bit. Quite weird, but it seems to be + * required for this to work + */ + desc.control |= DESC_IVALID; + memcpy_toio(desc_addr, &desc, sizeof(desc)); + + /* generate a MODULbus interrupt to the microcontroller */ + iowrite8(0x01, &mod->dpmctrl->interrupt); + + desc.control ^= DESC_VALID; + memcpy_toio(desc_addr, &desc, sizeof(desc)); + + /* update the next buffer pointer */ + mod->fasttx_num = (desc.control & DESC_WRAP) ? 0 + : (mod->fasttx_num + 1); + + /* if there is no free descriptor space, stop the transmit queue */ + if (!ican3_txok(mod)) + netif_stop_queue(ndev); + + spin_unlock_irqrestore(&mod->lock, flags); + return NETDEV_TX_OK; +} + +static const struct net_device_ops ican3_netdev_ops = { + .ndo_open = ican3_open, + .ndo_stop = ican3_stop, + .ndo_start_xmit = ican3_xmit, + .ndo_change_mtu = can_change_mtu, +}; + +static const struct ethtool_ops ican3_ethtool_ops = { + .get_ts_info = ethtool_op_get_ts_info, +}; + +/* + * Low-level CAN Device + */ + +/* This structure was stolen from drivers/net/can/sja1000/sja1000.c */ +static const struct can_bittiming_const ican3_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 = 64, + .brp_inc = 1, +}; + +static int ican3_set_mode(struct net_device *ndev, enum can_mode mode) +{ + struct ican3_dev *mod = netdev_priv(ndev); + int ret; + + if (mode != CAN_MODE_START) + return -ENOTSUPP; + + /* bring the bus online */ + ret = ican3_set_bus_state(mod, true); + if (ret) { + netdev_err(ndev, "unable to set bus-on\n"); + return ret; + } + + /* start up the network device */ + mod->can.state = CAN_STATE_ERROR_ACTIVE; + + if (netif_queue_stopped(ndev)) + netif_wake_queue(ndev); + + return 0; +} + +static int ican3_get_berr_counter(const struct net_device *ndev, + struct can_berr_counter *bec) +{ + struct ican3_dev *mod = netdev_priv(ndev); + int ret; + + ret = ican3_send_inquiry(mod, INQUIRY_STATUS); + if (ret) + return ret; + + if (!wait_for_completion_timeout(&mod->buserror_comp, HZ)) { + netdev_info(mod->ndev, "%s timed out\n", __func__); + return -ETIMEDOUT; + } + + bec->rxerr = mod->bec.rxerr; + bec->txerr = mod->bec.txerr; + return 0; +} + +/* + * Sysfs Attributes + */ + +static ssize_t termination_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct ican3_dev *mod = netdev_priv(to_net_dev(dev)); + int ret; + + ret = ican3_send_inquiry(mod, INQUIRY_TERMINATION); + if (ret) + return ret; + + if (!wait_for_completion_timeout(&mod->termination_comp, HZ)) { + netdev_info(mod->ndev, "%s timed out\n", __func__); + return -ETIMEDOUT; + } + + return sysfs_emit(buf, "%u\n", mod->termination_enabled); +} + +static ssize_t termination_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct ican3_dev *mod = netdev_priv(to_net_dev(dev)); + unsigned long enable; + int ret; + + if (kstrtoul(buf, 0, &enable)) + return -EINVAL; + + ret = ican3_set_termination(mod, enable); + if (ret) + return ret; + + return count; +} + +static ssize_t fwinfo_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct ican3_dev *mod = netdev_priv(to_net_dev(dev)); + + return scnprintf(buf, PAGE_SIZE, "%s\n", mod->fwinfo); +} + +static DEVICE_ATTR_RW(termination); +static DEVICE_ATTR_RO(fwinfo); + +static struct attribute *ican3_sysfs_attrs[] = { + &dev_attr_termination.attr, + &dev_attr_fwinfo.attr, + NULL, +}; + +static const struct attribute_group ican3_sysfs_attr_group = { + .attrs = ican3_sysfs_attrs, +}; + +/* + * PCI Subsystem + */ + +static int ican3_probe(struct platform_device *pdev) +{ + struct janz_platform_data *pdata; + struct net_device *ndev; + struct ican3_dev *mod; + struct resource *res; + struct device *dev; + int ret; + + pdata = dev_get_platdata(&pdev->dev); + if (!pdata) + return -ENXIO; + + dev_dbg(&pdev->dev, "probe: module number %d\n", pdata->modno); + + /* save the struct device for printing */ + dev = &pdev->dev; + + /* allocate the CAN device and private data */ + ndev = alloc_candev(sizeof(*mod), 0); + if (!ndev) { + dev_err(dev, "unable to allocate CANdev\n"); + ret = -ENOMEM; + goto out_return; + } + + platform_set_drvdata(pdev, ndev); + mod = netdev_priv(ndev); + mod->ndev = ndev; + mod->num = pdata->modno; + netif_napi_add_weight(ndev, &mod->napi, ican3_napi, ICAN3_RX_BUFFERS); + skb_queue_head_init(&mod->echoq); + spin_lock_init(&mod->lock); + init_completion(&mod->termination_comp); + init_completion(&mod->buserror_comp); + + /* setup device-specific sysfs attributes */ + ndev->sysfs_groups[0] = &ican3_sysfs_attr_group; + + /* the first unallocated page in the DPM is 9 */ + mod->free_page = DPM_FREE_START; + + ndev->netdev_ops = &ican3_netdev_ops; + ndev->ethtool_ops = &ican3_ethtool_ops; + ndev->flags |= IFF_ECHO; + SET_NETDEV_DEV(ndev, &pdev->dev); + + mod->can.clock.freq = ICAN3_CAN_CLOCK; + mod->can.bittiming_const = &ican3_bittiming_const; + mod->can.do_set_mode = ican3_set_mode; + mod->can.do_get_berr_counter = ican3_get_berr_counter; + mod->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES + | CAN_CTRLMODE_BERR_REPORTING + | CAN_CTRLMODE_ONE_SHOT; + + /* find our IRQ number */ + mod->irq = platform_get_irq(pdev, 0); + if (mod->irq < 0) { + ret = -ENODEV; + goto out_free_ndev; + } + + ndev->irq = mod->irq; + + /* get access to the MODULbus registers for this module */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(dev, "MODULbus registers not found\n"); + ret = -ENODEV; + goto out_free_ndev; + } + + mod->dpm = ioremap(res->start, resource_size(res)); + if (!mod->dpm) { + dev_err(dev, "MODULbus registers not ioremap\n"); + ret = -ENOMEM; + goto out_free_ndev; + } + + mod->dpmctrl = mod->dpm + DPM_PAGE_SIZE; + + /* get access to the control registers for this module */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + if (!res) { + dev_err(dev, "CONTROL registers not found\n"); + ret = -ENODEV; + goto out_iounmap_dpm; + } + + mod->ctrl = ioremap(res->start, resource_size(res)); + if (!mod->ctrl) { + dev_err(dev, "CONTROL registers not ioremap\n"); + ret = -ENOMEM; + goto out_iounmap_dpm; + } + + /* disable our IRQ, then hookup the IRQ handler */ + iowrite8(1 << mod->num, &mod->ctrl->int_disable); + ret = request_irq(mod->irq, ican3_irq, IRQF_SHARED, DRV_NAME, mod); + if (ret) { + dev_err(dev, "unable to request IRQ\n"); + goto out_iounmap_ctrl; + } + + /* reset and initialize the CAN controller into fast mode */ + napi_enable(&mod->napi); + ret = ican3_startup_module(mod); + if (ret) { + dev_err(dev, "%s: unable to start CANdev\n", __func__); + goto out_free_irq; + } + + /* register with the Linux CAN layer */ + ret = register_candev(ndev); + if (ret) { + dev_err(dev, "%s: unable to register CANdev\n", __func__); + goto out_free_irq; + } + + netdev_info(mod->ndev, "module %d: registered CAN device\n", pdata->modno); + return 0; + +out_free_irq: + napi_disable(&mod->napi); + iowrite8(1 << mod->num, &mod->ctrl->int_disable); + free_irq(mod->irq, mod); +out_iounmap_ctrl: + iounmap(mod->ctrl); +out_iounmap_dpm: + iounmap(mod->dpm); +out_free_ndev: + free_candev(ndev); +out_return: + return ret; +} + +static int ican3_remove(struct platform_device *pdev) +{ + struct net_device *ndev = platform_get_drvdata(pdev); + struct ican3_dev *mod = netdev_priv(ndev); + + /* unregister the netdevice, stop interrupts */ + unregister_netdev(ndev); + napi_disable(&mod->napi); + iowrite8(1 << mod->num, &mod->ctrl->int_disable); + free_irq(mod->irq, mod); + + /* put the module into reset */ + ican3_shutdown_module(mod); + + /* unmap all registers */ + iounmap(mod->ctrl); + iounmap(mod->dpm); + + free_candev(ndev); + + return 0; +} + +static struct platform_driver ican3_driver = { + .driver = { + .name = DRV_NAME, + }, + .probe = ican3_probe, + .remove = ican3_remove, +}; + +module_platform_driver(ican3_driver); + +MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>"); +MODULE_DESCRIPTION("Janz MODULbus VMOD-ICAN3 Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:janz-ican3"); |