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WSL2-Linux-Kernel/drivers/net/can/janz-ican3.c

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47 KiB
C
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/*
* Janz MODULbus VMOD-ICAN3 CAN Interface Driver
*
* Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
*
* 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; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/netdevice.h>
#include <linux/can.h>
#include <linux/can/dev.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 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
/*
* 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
/*
* 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
/* 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;
/* Device for printing */
struct device *dev;
/* 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;
/* 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) {
dev_dbg(mod->dev, "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) {
dev_err(mod->dev, "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 __devinit 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 __devinit 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)) {
dev_dbg(mod->dev, "%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)) {
dev_dbg(mod->dev, "%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 __devinit 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 __devexit 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 __devinit 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 __devinit 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 __devinit 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 ican3_msg msg;
memset(&msg, 0, sizeof(msg));
msg.spec = on ? MSG_CONREQ : MSG_COFFREQ;
msg.len = cpu_to_le16(0);
return ican3_send_msg(mod, &msg);
}
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;
memset(&msg, 0, sizeof(msg));
msg.spec = MSG_CCONFREQ;
msg.len = cpu_to_le16(2);
msg.data[0] = 0x00;
msg.data[1] = quota;
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->can_dlc = get_can_dlc(desc->data[1] & ICAN3_CAN_DLC_MASK);
memcpy(cf->data, &desc->data[2], cf->can_dlc);
} else {
cf->can_dlc = get_can_dlc(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->can_dlc);
}
}
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->can_dlc;
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->can_dlc);
}
/*
* 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)
{
dev_dbg(mod->dev, "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) {
dev_err(mod->dev, "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) {
dev_err(mod->dev, "unable to handle errors on non-SJA1000\n");
return -ENODEV;
}
/* check the message length for sanity */
if (le16_to_cpu(msg->len) < 6) {
dev_err(mod->dev, "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;
dev_dbg(mod->dev, "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) {
dev_err(mod->dev, "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) {
dev_dbg(mod->dev, "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) {
dev_dbg(mod->dev, "error warning + passive interrupt\n");
if (status & SR_BS) {
state = CAN_STATE_BUS_OFF;
cf->can_id |= CAN_ERR_BUSOFF;
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;
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[2] |= CAN_ERR_PROT_UNSPEC;
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;
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:
dev_err(mod->dev, "received an unknown inquiry response\n");
break;
}
}
static void ican3_handle_unknown_message(struct ican3_dev *mod,
struct ican3_msg *msg)
{
dev_warn(mod->dev, "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)
{
dev_dbg(mod->dev, "%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;
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)
{
struct sock *srcsk = skb->sk;
if (atomic_read(&skb->users) != 1) {
struct sk_buff *old_skb = skb;
skb = skb_clone(old_skb, GFP_ATOMIC);
kfree_skb(old_skb);
if (!skb)
return;
} else {
skb_orphan(skb);
}
skb->sk = srcsk;
/* 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;
/* 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;
dlc = cf->can_dlc;
/* 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->can_dlc != echo_cf->can_dlc)
return false;
return memcmp(cf->data, echo_cf->data, cf->can_dlc) == 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++;
stats->rx_bytes += cf->can_dlc;
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(napi);
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)
{
u8 val = 1 << mod->num;
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(val, &mod->ctrl->reset_assert);
iowrite8(val, &mod->ctrl->reset_deassert);
/* 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 / 4));
dev_err(mod->dev, "failed to reset CAN module\n");
return -ETIMEDOUT;
}
static void __devexit 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 __devinit ican3_startup_module(struct ican3_dev *mod)
{
int ret;
ret = ican3_reset_module(mod);
if (ret) {
dev_err(mod->dev, "unable to reset module\n");
return ret;
}
/* re-enable interrupts so we can send messages */
iowrite8(1 << mod->num, &mod->ctrl->int_enable);
ret = ican3_msg_connect(mod);
if (ret) {
dev_err(mod->dev, "unable to connect to module\n");
return ret;
}
ican3_init_new_host_interface(mod);
ret = ican3_msg_newhostif(mod);
if (ret) {
dev_err(mod->dev, "unable to switch to new-style interface\n");
return ret;
}
/* default to "termination on" */
ret = ican3_set_termination(mod, true);
if (ret) {
dev_err(mod->dev, "unable to enable termination\n");
return ret;
}
/* default to "bus errors enabled" */
ret = ican3_set_buserror(mod, 1);
if (ret) {
dev_err(mod->dev, "unable to set bus-error\n");
return ret;
}
ican3_init_fast_host_interface(mod);
ret = ican3_msg_fasthostif(mod);
if (ret) {
dev_err(mod->dev, "unable to switch to fast host interface\n");
return ret;
}
ret = ican3_set_id_filter(mod, true);
if (ret) {
dev_err(mod->dev, "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) {
dev_err(mod->dev, "unable to start CAN layer\n");
return ret;
}
/* bring the bus online */
ret = ican3_set_bus_state(mod, true);
if (ret) {
dev_err(mod->dev, "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) {
dev_err(mod->dev, "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 int 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_dropped_invalid_skb(ndev, skb))
return NETDEV_TX_OK;
spin_lock_irqsave(&mod->lock, flags);
/* check that we can actually transmit */
if (!ican3_txok(mod)) {
dev_err(mod->dev, "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,
};
/*
* 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,
};
/*
* This routine 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
*/
static int ican3_set_bittiming(struct net_device *ndev)
{
struct ican3_dev *mod = netdev_priv(ndev);
struct can_bittiming *bt = &mod->can.bittiming;
struct ican3_msg msg;
u8 btr0, btr1;
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;
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;
return ican3_send_msg(mod, &msg);
}
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) {
dev_err(mod->dev, "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;
ret = wait_for_completion_timeout(&mod->buserror_comp, HZ);
if (ret <= 0) {
dev_info(mod->dev, "%s timed out\n", __func__);
return -ETIMEDOUT;
}
bec->rxerr = mod->bec.rxerr;
bec->txerr = mod->bec.txerr;
return 0;
}
/*
* Sysfs Attributes
*/
static ssize_t ican3_sysfs_show_term(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;
ret = wait_for_completion_timeout(&mod->termination_comp, HZ);
if (ret <= 0) {
dev_info(mod->dev, "%s timed out\n", __func__);
return -ETIMEDOUT;
}
return snprintf(buf, PAGE_SIZE, "%u\n", mod->termination_enabled);
}
static ssize_t ican3_sysfs_set_term(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 (strict_strtoul(buf, 0, &enable))
return -EINVAL;
ret = ican3_set_termination(mod, enable);
if (ret)
return ret;
return count;
}
static DEVICE_ATTR(termination, S_IWUSR | S_IRUGO, ican3_sysfs_show_term,
ican3_sysfs_set_term);
static struct attribute *ican3_sysfs_attrs[] = {
&dev_attr_termination.attr,
NULL,
};
static struct attribute_group ican3_sysfs_attr_group = {
.attrs = ican3_sysfs_attrs,
};
/*
* PCI Subsystem
*/
static int __devinit 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 = pdev->dev.platform_data;
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->dev = &pdev->dev;
mod->num = pdata->modno;
netif_napi_add(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->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_bittiming = ican3_set_bittiming;
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) {
dev_err(dev, "IRQ line not found\n");
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;
}
dev_info(dev, "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 __devexit 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,
.owner = THIS_MODULE,
},
.probe = ican3_probe,
.remove = __devexit_p(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");
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