can3--socketcan之mcp251x.c

2019-11-09 14:29:48

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轉(zhuǎn)自http://www.cnblogs.com/-song/archive/2012/05/24/3331872.html

spi驅(qū)動(dòng)結(jié)構(gòu)見http://blog.csdn.net/songQQnew/article/details/7037583mcp251x.c幾乎是抄襲dm9000的寫作格式參考

dm9000 driver 1

理清一下驅(qū)動(dòng)的線索******************************************************************在init函數(shù)中注冊(cè)spi驅(qū)動(dòng)mcp251x_can_driver

static int __init mcp251x_can_init(void) { DBG("init/n"); return spi_register_driver(&mcp251x_can_driver); }

在spi驅(qū)動(dòng)mcp251x_can_driver的PRobe函數(shù)中分配net_device

static struct spi_driver mcp251x_can_driver = { .driver = { .name = DEVICE_NAME,//mcp2515 .bus = &spi_bus_type, .owner = THIS_MODULE, }, .id_table = mcp251x_id_table, .probe = mcp251x_can_probe,//probe .remove = __devexit_p(mcp251x_can_remove), .suspend = mcp251x_can_suspend, .resume = mcp251x_can_resume, }; static int __devinit mcp251x_can_probe(struct spi_device *spi) { net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX); if (!net) { ret = -ENOMEM; goto error_alloc; } //注冊(cè)net_device register_candev(net); //net_device的Operation結(jié)構(gòu)體指定了操作函數(shù)集合 static const struct net_device_ops mcp251x_netdev_ops = { .ndo_open = mcp251x_open, .ndo_stop = mcp251x_stop, .ndo_start_xmit = mcp251x_hard_start_xmit, }; }

應(yīng)用層執(zhí)行ifconfig can0 up時(shí)會(huì)調(diào)用到mcp251x_open在mcp251x_open函數(shù)中,

//打開設(shè)備 open_candev(net); //申請(qǐng)中斷 ret = request_irq(spi->irq, mcp251x_can_irq, /*IRQF_DISABLED |*/ IRQF_TRIGGER_LOW , DEVICE_NAME, priv); //初始化工作隊(duì)列，當(dāng)做中斷(接收)下半部，用于處理接收 INIT_WORK(&priv->irq_work,can_irq_work); //初始化工作隊(duì)列，用于處理發(fā)送 INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);

應(yīng)用層執(zhí)行write socket時(shí)會(huì)調(diào)用到mcp251x_hard_start_xmit，在 mcp251x_hard_start_xmit函數(shù)中，

//停止協(xié)議棧向驅(qū)動(dòng)發(fā)送數(shù)據(jù)(在發(fā)送數(shù)據(jù)的時(shí)候需要停止協(xié)議棧發(fā)來新的需要發(fā)送出去的數(shù)據(jù))，發(fā)送完成后會(huì)重新啟用 netif_stop_queue(net); //啟動(dòng)發(fā)送工作隊(duì)列，將數(shù)據(jù)(skb)發(fā)送出去 priv->tx_skb = skb; queue_work(priv->wq, &priv->tx_work);

具體看一下這個(gè)發(fā)送工作隊(duì)列函數(shù)

static void mcp251x_tx_work_handler(struct work_struct *ws) { struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, tx_work); struct spi_device *spi = priv->spi; struct net_device *net = priv->net; struct can_frame *frame; // printk("mcp251x_tx_work_handler/n"); mutex_lock(&priv->mcp_lock); if (priv->tx_skb) { if (priv->can.state == CAN_STATE_BUS_OFF) { mcp251x_clean(net); } else { frame = (struct can_frame *)priv->tx_skb->data; if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN) frame->can_dlc = CAN_FRAME_MAX_DATA_LEN; mcp251x_hw_tx(spi, frame, 0); priv->tx_len = 1 + frame->can_dlc; can_put_echo_skb(priv->tx_skb, net, 0); priv->tx_skb = NULL; } } mutex_unlock(&priv->mcp_lock); }

怎么接收呢？當(dāng)然是在中斷處理函數(shù)中接收，有中斷產(chǎn)生時(shí)，會(huì)啟用一個(gè)負(fù)責(zé)接受的工作隊(duì)列，即中斷下半部，去接收。并將接收到的數(shù)據(jù)保存，以供應(yīng)用層使用read socket等來讀取。

static irqreturn_t mcp251x_can_irq(int irq, void *dev_id) { DBG("zhongduan :mcp251x_can_irq/n"); struct mcp251x_priv *priv = dev_id; disable_irq_nosync(irq);//禁止中斷，工作隊(duì)列函數(shù)中接收完成時(shí)會(huì)重新使能中斷 if (!work_pending(&priv->irq_work)) queue_work(priv->wq, &priv->irq_work);//調(diào)用工作隊(duì)列函數(shù) return IRQ_HANDLED; }

接收工作隊(duì)列函數(shù)

void can_irq_work(struct work_struct *ws) { DBG("zhongduan bottom: can_irq_work/n"); struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, irq_work); struct spi_device *spi = priv->spi; struct net_device *net = priv->net; mutex_lock(&priv->mcp_lock); //mcp251x_write_reg(spi, CANINTE, (intset & (~ ( CANINTE_TX2IE) ))); while (!priv->force_quit) { enum can_state new_state; u8 intf, eflag; u8 clear_intf = 0; int can_id = 0, data1 = 0; mcp251x_read_2regs(spi, CANINTF, &intf, &eflag); DBG("intf=%x/n",intf);//一般返回1，表示rxb0里有數(shù)據(jù)。 //mcp251x_write_bits(spi, CANINTF, intf, 0x00); /* mask out flags we don't care about */ intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR ;//| CANINTF_MERRF; if (intf & CANINTF_TX) {//如果是發(fā)送完成中斷 net->stats.tx_packets++; net->stats.tx_bytes += priv->tx_len - 1; if (priv->tx_len) { can_get_echo_skb(net, 0); priv->tx_len = 0; } netif_wake_queue(net);//重新開啟 } /* receive buffer 1 */ if (intf & CANINTF_RX1IF) {//如果是從mcp251x的buffer 1接收到數(shù)據(jù)的中斷 mcp251x_hw_rx(spi, 1);//接收 /* the MCP2515 does this automatically */ if (mcp251x_is_2510(spi)) clear_intf |= CANINTF_RX1IF;//清除mcp251x里的中斷標(biāo)志 } /* receive buffer 0 */ if (intf & CANINTF_RX0IF) {//如果是從mcp251x的buffer 0接收到數(shù)據(jù)的中斷 mcp251x_hw_rx(spi, 0);//接收mcp2515的rxb0里的數(shù)據(jù)，見下 /* * Free one buffer ASAP * (The MCP2515 does this automatically.) */ if (mcp251x_is_2510(spi)) mcp251x_write_bits(spi, CANINTF, CANINTF_RX0IF, 0x00);//清除mcp251x里的中斷標(biāo)志 } /* any error or tx interrupt we need to clear? */ if (intf & (CANINTF_ERR | CANINTF_TX)) clear_intf |= intf & (CANINTF_ERR | CANINTF_TX); if (clear_intf) mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00); if (eflag) mcp251x_write_bits(spi, EFLG, eflag, 0x00); /* Update can state */ if (eflag & EFLG_TXBO) { new_state = CAN_STATE_BUS_OFF; can_id |= CAN_ERR_BUSOFF; } else if (eflag & EFLG_TXEP) { new_state = CAN_STATE_ERROR_PASSIVE; can_id |= CAN_ERR_CRTL; data1 |= CAN_ERR_CRTL_TX_PASSIVE; } else if (eflag & EFLG_RXEP) { new_state = CAN_STATE_ERROR_PASSIVE; can_id |= CAN_ERR_CRTL; data1 |= CAN_ERR_CRTL_RX_PASSIVE; } else if (eflag & EFLG_TXWAR) { new_state = CAN_STATE_ERROR_WARNING; can_id |= CAN_ERR_CRTL; data1 |= CAN_ERR_CRTL_TX_WARNING; } else if (eflag & EFLG_RXWAR) { new_state = CAN_STATE_ERROR_WARNING; can_id |= CAN_ERR_CRTL; data1 |= CAN_ERR_CRTL_RX_WARNING; } else { new_state = CAN_STATE_ERROR_ACTIVE; } /* Update can state statistics */ switch (priv->can.state) { case CAN_STATE_ERROR_ACTIVE: if (new_state >= CAN_STATE_ERROR_WARNING && new_state <= CAN_STATE_BUS_OFF) priv->can.can_stats.error_warning++; case CAN_STATE_ERROR_WARNING: /* fallthrough */ if (new_state >= CAN_STATE_ERROR_PASSIVE && new_state <= CAN_STATE_BUS_OFF) priv->can.can_stats.error_passive++; break; default: break; } priv->can.state = new_state; if (intf & CANINTF_ERRIF) { /* Handle overflow counters */ if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) { if (eflag & EFLG_RX0OVR) { net->stats.rx_over_errors++; net->stats.rx_errors++; } if (eflag & EFLG_RX1OVR) { net->stats.rx_over_errors++; net->stats.rx_errors++; } can_id |= CAN_ERR_CRTL; data1 |= CAN_ERR_CRTL_RX_OVERFLOW; } mcp251x_error_skb(net, can_id, data1); } if (priv->can.state == CAN_STATE_BUS_OFF) { if (priv->can.restart_ms == 0) { priv->force_quit = 1; can_bus_off(net); mcp251x_hw_sleep(spi); break; } } if (intf == 0) break; } //mcp251x_write_reg(spi, CANINTE, intset); mutex_unlock(&priv->mcp_lock); enable_irq(spi->irq);//重新使能中斷 //s3c_gpio_cfgpin(S3C64XX_GPL(8), S3C_GPIO_SFN(3)); }

附mcp251x.c源碼

/* * CAN bus driver for Microchip 251x CAN Controller with SPI Interface * * MCP2510 support and bug fixes by Christian Pellegrin * <chripell@evolware.org> * * Copyright 2009 Christian Pellegrin EVOL S.r.l. * * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved. * Written under contract by: * Chris Elston, Katalix Systems, Ltd. * * Based on Microchip MCP251x CAN controller driver written by * David Vrabel, Copyright 2006 Arcom Control Systems Ltd. * * Based on CAN bus driver for the CCAN controller written by * - Sascha Hauer, Marc Kleine-Budde, Pengutronix * - Simon Kallweit, intefo AG * Copyright 2007 * * This program is free software; you can redistribute it and/or modify * it under the terms of the version 2 of the GNU General Public License * as published by the Free Software Foundation * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * * * Your platform definition file should specify something like: * * static struct mcp251x_platform_data mcp251x_info = { * .oscillator_frequency = 8000000, * .board_specific_setup = &mcp251x_setup, * .power_enable = mcp251x_power_enable, * .transceiver_enable = NULL, * }; * * static struct spi_board_info spi_board_info[] = { * { * .modalias = "mcp2510", * // or "mcp2515" depending on your controller * .platform_data = &mcp251x_info, * .irq = IRQ_EINT13, * .max_speed_hz = 2*1000*1000, * .chip_select = 2, * }, * }; * * Please see mcp251x.h for a description of the fields in * struct mcp251x_platform_data. * */ #define DEBUG #ifdef DEBUG #define DBG(...) printk(" DBG(%s, %s(), %d): ", __FILE__, __FUNCTION__, __LINE__); printk(__VA_ARGS__) #else #define DBG(...) #endif #include <linux/can/core.h> #include <linux/can/dev.h> #include <linux/can/platform/mcp251x.h> #include <linux/completion.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/dma-mapping.h> #include <linux/freezer.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/netdevice.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/spi/spi.h> #include <linux/u access.h> #include <linux/gpio.h> #include <plat/gpio-cfg.h> /* SPI interface instruction set */ #define INSTRUCTION_WRITE 0x02 #define INSTRUCTION_READ 0x03 #define INSTRUCTION_BIT_MODIFY 0x05 #define INSTRUCTION_LOAD_TXB(n) (0x40 + 2 * (n)) #define INSTRUCTION_READ_RXB(n) (((n) == 0) ? 0x90 : 0x94) #define INSTRUCTION_RESET 0xC0 /* MPC251x registers */ #define CANSTAT 0x0e #define CANCTRL 0x0f # define CANCTRL_REQOP_MASK 0xe0 # define CANCTRL_REQOP_CONF 0x80 # define CANCTRL_REQOP_LISTEN_ONLY 0x60 # define CANCTRL_REQOP_LOOPBACK 0x40 # define CANCTRL_REQOP_SLEEP 0x20 # define CANCTRL_REQOP_NORMAL 0x00 # define CANCTRL_OSM 0x08 # define CANCTRL_ABAT 0x10 #define TEC 0x1c #define REC 0x1d #define CNF1 0x2a # define CNF1_SJW_SHIFT 6 #define CNF2 0x29 # define CNF2_BTLMODE 0x80 # define CNF2_SAM 0x40 # define CNF2_PS1_SHIFT 3 #define CNF3 0x28 # define CNF3_SOF 0x08 # define CNF3_WAKFIL 0x04 # define CNF3_PHSEG2_MASK 0x07 #define CANINTE 0x2b # define CANINTE_MERRE 0x80 # define CANINTE_WAKIE 0x40 # define CANINTE_ERRIE 0x20 # define CANINTE_TX2IE 0x10 # define CANINTE_TX1IE 0x08 # define CANINTE_TX0IE 0x04 # define CANINTE_RX1IE 0x02 # define CANINTE_RX0IE 0x01 #define CANINTF 0x2c # define CANINTF_MERRF 0x80 # define CANINTF_WAKIF 0x40 # define CANINTF_ERRIF 0x20 # define CANINTF_TX2IF 0x10 # define CANINTF_TX1IF 0x08 # define CANINTF_TX0IF 0x04 # define CANINTF_RX1IF 0x02 # define CANINTF_RX0IF 0x01 # define CANINTF_RX (CANINTF_RX0IF | CANINTF_RX1IF) # define CANINTF_TX (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF) # define CANINTF_ERR (CANINTF_ERRIF) #define EFLG 0x2d # define EFLG_EWARN 0x01 # define EFLG_RXWAR 0x02 # define EFLG_TXWAR 0x04 # define EFLG_RXEP 0x08 # define EFLG_TXEP 0x10 # define EFLG_TXBO 0x20 # define EFLG_RX0OVR 0x40 # define EFLG_RX1OVR 0x80 #define TXBCTRL(n) (((n) * 0x10) + 0x30 + TXBCTRL_OFF) # define TXBCTRL_ABTF 0x40 # define TXBCTRL_MLOA 0x20 # define TXBCTRL_TXERR 0x10 # define TXBCTRL_TXREQ 0x08 #define TXBSIDH(n) (((n) * 0x10) + 0x30 + TXBSIDH_OFF) # define SIDH_SHIFT 3 #define TXBSIDL(n) (((n) * 0x10) + 0x30 + TXBSIDL_OFF) # define SIDL_SID_MASK 7 # define SIDL_SID_SHIFT 5 # define SIDL_EXIDE_SHIFT 3 # define SIDL_EID_SHIFT 16 # define SIDL_EID_MASK 3 #define TXBEID8(n) (((n) * 0x10) + 0x30 + TXBEID8_OFF) #define TXBEID0(n) (((n) * 0x10) + 0x30 + TXBEID0_OFF) #define TXBDLC(n) (((n) * 0x10) + 0x30 + TXBDLC_OFF) # define DLC_RTR_SHIFT 6 #define TXBCTRL_OFF 0 #define TXBSIDH_OFF 1 #define TXBSIDL_OFF 2 #define TXBEID8_OFF 3 #define TXBEID0_OFF 4 #define TXBDLC_OFF 5 #define TXBDAT_OFF 6 #define RXBCTRL(n) (((n) * 0x10) + 0x60 + RXBCTRL_OFF) # define RXBCTRL_BUKT 0x04 # define RXBCTRL_RXM0 0x20 # define RXBCTRL_RXM1 0x40 #define RXBSIDH(n) (((n) * 0x10) + 0x60 + RXBSIDH_OFF) # define RXBSIDH_SHIFT 3 #define RXBSIDL(n) (((n) * 0x10) + 0x60 + RXBSIDL_OFF) # define RXBSIDL_IDE 0x08 # define RXBSIDL_SRR 0x10 # define RXBSIDL_EID 3 # define RXBSIDL_SHIFT 5 #define RXBEID8(n) (((n) * 0x10) + 0x60 + RXBEID8_OFF) #define RXBEID0(n) (((n) * 0x10) + 0x60 + RXBEID0_OFF) #define RXBDLC(n) (((n) * 0x10) + 0x60 + RXBDLC_OFF) # define RXBDLC_LEN_MASK 0x0f # define RXBDLC_RTR 0x40 #define RXBCTRL_OFF 0 #define RXBSIDH_OFF 1 #define RXBSIDL_OFF 2 #define RXBEID8_OFF 3 #define RXBEID0_OFF 4 #define RXBDLC_OFF 5 #define RXBDAT_OFF 6 #define RXFSIDH(n) ((n) * 4) #define RXFSIDL(n) ((n) * 4 + 1) #define RXFEID8(n) ((n) * 4 + 2) #define RXFEID0(n) ((n) * 4 + 3) #define RXMSIDH(n) ((n) * 4 + 0x20) #define RXMSIDL(n) ((n) * 4 + 0x21) #define RXMEID8(n) ((n) * 4 + 0x22) #define RXMEID0(n) ((n) * 4 + 0x23) #define GET_BYTE(val, byte) / (((val) >> ((byte) * 8)) & 0xff) #define SET_BYTE(val, byte) / (((val) & 0xff) << ((byte) * 8)) /* * Buffer size required for the largest SPI transfer (i.e., reading a * frame) */ #define CAN_FRAME_MAX_DATA_LEN 8 #define SPI_TRANSFER_BUF_LEN (6 + CAN_FRAME_MAX_DATA_LEN) #define CAN_FRAME_MAX_BITS 128 #define TX_ECHO_SKB_MAX 1 #define DEVICE_NAME "mcp2515" //static struct timer_list check_timer; void can_irq_work(struct work_struct *ws); //static struct work_struct can_work; static int intset;//中斷設(shè)置 static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */ module_param(mcp251x_enable_dma, int, S_IRUGO); MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)"); static struct can_bittiming_const mcp251x_bittiming_const = { .name = DEVICE_NAME, .tseg1_min = 3, .tseg1_max = 16, .tseg2_min = 2, .tseg2_max = 8, .sjw_max = 4, .brp_min = 1, .brp_max = 64, .brp_inc = 1, }; enum mcp251x_model { CAN_MCP251X_MCP2510 = 0x2510, CAN_MCP251X_MCP2515 = 0x2515, }; struct mcp251x_priv { struct can_priv can; struct net_device *net; struct spi_device *spi; enum mcp251x_model model; struct mutex mcp_lock; /* SPI device lock */ u8 *spi_tx_buf; u8 *spi_rx_buf; dma_addr_t spi_tx_dma; dma_addr_t spi_rx_dma; struct sk_buff *tx_skb; int tx_len; struct workqueue_struct *wq; struct work_struct tx_work; struct work_struct restart_work; struct work_struct irq_work; int force_quit; int after_suspend; #define AFTER_SUSPEND_UP 1 #define AFTER_SUSPEND_DOWN 2 #define AFTER_SUSPEND_POWER 4 #define AFTER_SUSPEND_RESTART 8 int restart_tx; }; #define MCP251X_IS(_model) / static inline int mcp251x_is_##_model(struct spi_device *spi) / { / struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); / return priv->model == CAN_MCP251X_MCP##_model; / } MCP251X_IS(2510); MCP251X_IS(2515); static void mcp251x_clean(struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); // DBG("mcp251x_clean/n"); if (priv->tx_skb || priv->tx_len) net->stats.tx_errors++; if (priv->tx_skb) dev_kfree_skb(priv->tx_skb); if (priv->tx_len) can_free_echo_skb(priv->net, 0); priv->tx_skb = NULL; priv->tx_len = 0; } /* * Note about handling of error return of mcp251x_spi_trans: accessing * registers via SPI is not really different conceptually than using * normal I/O assembler instructions, although it's much more * complicated from a practical POV. So it's not advisable to always * check the return value of this function. Imagine that every * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0) * error();", it would be a great mess (well there are some situation * when exception handling C++ like could be useful after all). So we * just check that transfers are OK at the beginning of our * conversation with the chip and to avoid doing really nasty things * (like injecting bogus packets in the network stack). */ static int mcp251x_spi_trans(struct spi_device *spi, int len) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); struct spi_transfer t = { .tx_buf = priv->spi_tx_buf, .rx_buf = priv->spi_rx_buf, .len = len, .cs_change = 0, }; struct spi_message m; int ret; // DBG("mcp251x_spi_trans/n"); spi_message_init(&m); if (mcp251x_enable_dma) { t.tx_dma = priv->spi_tx_dma; t.rx_dma = priv->spi_rx_dma; m.is_dma_mapped = 1; } spi_message_add_tail(&t, &m); ret = spi_sync(spi, &m); //ret= spi_async (spi,&m); if (ret) dev_err(&spi->dev, "spi transfer failed: ret = %d/n", ret); int i=0; DBG("打印spi直接發(fā)送的數(shù)據(jù)/n"); for( i=0;i<len;i++) { DBG("priv->spi_tx_buf[%d]=%x/n",i,priv->spi_tx_buf[i]); } DBG("打印spi直接收到的數(shù)據(jù)/n"); for( i=0;i<len;i++) { DBG("priv->spi_rx_buf[%d]=%x/n",i,priv->spi_rx_buf[i]); } return ret; } static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); u8 val = 0; //INSTRUCTION_READ=3 //根據(jù)mcp2515手冊(cè)p64，使用spi接口讀取寄存器的步驟是發(fā)送命令03+地址 //接收到的寄存器數(shù)據(jù)在spi_rx_buf[2] priv->spi_tx_buf[0] = INSTRUCTION_READ; priv->spi_tx_buf[1] = reg; mcp251x_spi_trans(spi, 3); val = priv->spi_rx_buf[2]; return val; } static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg, uint8_t *v1, uint8_t *v2) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); priv->spi_tx_buf[0] = INSTRUCTION_READ; priv->spi_tx_buf[1] = reg; mcp251x_spi_trans(spi, 4); ////接收到的寄存器數(shù)據(jù)在spi_rx_buf[2]，spi_rx_buf[3] *v1 = priv->spi_rx_buf[2]; *v2 = priv->spi_rx_buf[3]; } static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); //INSTRUCTION_WRITE=2 //根據(jù)mcp2515手冊(cè)p64，使用spi接口寫寄存器的步驟是發(fā)送命令02+地址+值 priv->spi_tx_buf[0] = INSTRUCTION_WRITE; priv->spi_tx_buf[1] = reg; priv->spi_tx_buf[2] = val; mcp251x_spi_trans(spi, 3); } static void mcp251x_write_bits(struct spi_device *spi, u8 reg, u8 mask, uint8_t val) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); //INSTRUCTION_BIT_MODIFY=5 //位修改指令，對(duì)可執(zhí)行位操作的寄存器有效 priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY; priv->spi_tx_buf[1] = reg; priv->spi_tx_buf[2] = mask; priv->spi_tx_buf[3] = val; mcp251x_spi_trans(spi, 4); } static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf, int len, int tx_buf_idx) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); //如果是2510,還需要指定使用那個(gè)發(fā)送緩沖區(qū)發(fā)送數(shù)據(jù) // if (mcp251x_is_2510(spi)) { int i; for (i = 1; i < TXBDAT_OFF + len; i++) mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i, buf[i]); } else { memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len); mcp251x_spi_trans(spi, TXBDAT_OFF + len); } } static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame, int tx_buf_idx) { u32 sid, eid, exide, rtr; u8 buf[SPI_TRANSFER_BUF_LEN]; exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */ DBG("打印是否擴(kuò)展幀/n"); if (exide) { sid = (frame->can_id & CAN_EFF_MASK) >> 18; DBG("是擴(kuò)展幀/n"); } else { sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */ DBG("是標(biāo)準(zhǔn)幀/n"); } eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */ rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */ //INSTRUCTION_LOAD_TXB(0)=0x40,即裝載tx0緩沖器 buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx); buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT; buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) | (exide << SIDL_EXIDE_SHIFT) | ((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK); buf[TXBEID8_OFF] = GET_BYTE(eid, 1); buf[TXBEID0_OFF] = GET_BYTE(eid, 0); buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->can_dlc; memcpy(buf + TXBDAT_OFF, frame->data, frame->can_dlc); int i; DBG("打印送給spi的數(shù)據(jù)/n"); for(i=0;i<SPI_TRANSFER_BUF_LEN;i++) { DBG("buf[%d]=%x/n",i,buf[i]); } mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx);//裝載到tx0緩沖器 mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx), TXBCTRL_TXREQ);//請(qǐng)求發(fā)送tx0 } static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf, int buf_idx) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); // DBG("mcp251x_hw_rx_frame/n"); DBG("打印是否是mcp2515/n"); if (mcp251x_is_2510(spi)) { DBG("是mcp2510/n"); int i, len; for (i = 1; i < RXBDAT_OFF; i++) buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i); len = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK); for (; i < (RXBDAT_OFF + len); i++) buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i); } else { DBG("是mcp2515/n"); //INSTRUCTION_READ_RXB(0)=90,即讀取rx0緩沖器 priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx); /*SPI_TRANSFER_BUF_LEN=14，即spi的發(fā)送和接收緩沖區(qū)都設(shè)為14 因?yàn)閙cp2515共返回14個(gè)字節(jié)，假如是讀rxbuf0,則 RXBOCTRL RXB0SIDH RXB0SIDL RXB0EID8 RXB0EID0 RXB0DLC RXB0D0 ... RXB0D7 */ mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN); memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN); } } static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); struct sk_buff *skb; struct can_frame *frame; u8 buf[SPI_TRANSFER_BUF_LEN]; // DBG("mcp251x_hw_rx/n"); skb = alloc_can_skb(priv->net, &frame); if (!skb) { dev_err(&spi->dev, "cannot allocate RX skb/n"); priv->net->stats.rx_dropped++; return; } mcp251x_hw_rx_frame(spi, buf, buf_idx);// 接收數(shù)據(jù) DBG("打印從spi接收到buf里的數(shù)據(jù)/n"); DBG(" buf_idx=%d/n",buf_idx); int i; for(i=0;i<SPI_TRANSFER_BUF_LEN;i++) { DBG(" buf[%d]=%x/n",i,buf[i]); } DBG("打印是否是擴(kuò)展幀/n"); if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) { //buf[RXBSIDL_OFF]即buf[2]即寄存器RXBnSIDL的第4位表示是否是擴(kuò)展幀 DBG("是擴(kuò)展幀/n"); /* Extended ID format */ frame->can_id = CAN_EFF_FLAG; frame->can_id |= /* Extended ID part */ SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) | SET_BYTE(buf[RXBEID8_OFF], 1) | SET_BYTE(buf[RXBEID0_OFF], 0) | /* Standard ID part */ (((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) | (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18); /* Remote transmission request */ if (buf[RXBDLC_OFF] & RXBDLC_RTR) frame->can_id |= CAN_RTR_FLAG; } else { DBG("是標(biāo)準(zhǔn)幀/n"); /* Standard ID format */ //RXBSIDH的全8位和RXBSIDL的高3位即11位共同組成標(biāo)準(zhǔn)幀的標(biāo)識(shí)符，詳見mcp2515手冊(cè)， //所以理論上一條can總線最多可分辨2048個(gè)設(shè)備(擴(kuò)展幀也是11位標(biāo)識(shí)符) //如果 //buf[1]=寄存器RXBSIDH=0x24=0010 0100,<<3=0010 0100 000 //buf[2]=寄存器RXBSIDL=0x60=0110 0000,>>5=011 //加上之后=001 0010 0011=0x123 frame->can_id = (buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) | (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT); if (buf[RXBSIDL_OFF] & RXBSIDL_SRR) frame->can_id |= CAN_RTR_FLAG; } /* Data length */ //buf[3]=寄存器RXBEID8，標(biāo)準(zhǔn)幀不使用 //buf[4]=寄存器RXBEID0，標(biāo)準(zhǔn)幀不使用 //buf[5]=寄存器RXBDLC=數(shù)據(jù)段長(zhǎng)度 frame->can_dlc = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK); //buf[6]-buf[13]=8個(gè)數(shù)據(jù)寄存器RXB0D0-RXB0D7 memcpy(frame->data, buf + RXBDAT_OFF, frame->can_dlc); DBG("打印can_frame的字段/n"); DBG(" frame->can_id=0x%x/n", frame->can_id); char *p=(char*)&(frame->can_id); for(i=0;i<4;i++) { DBG(" p=%x/n",*p); p++; } DBG(" frame->can_dlc=%d/n", frame->can_dlc); for(i=0;i<8;i++) { DBG(" frame->data[%d]=%x/n",i,frame->data[i]); } priv->net->stats.rx_packets++; priv->net->stats.rx_bytes += frame->can_dlc; DBG("打印skb里的數(shù)據(jù)/n"); for(i=0;i<20;i++) { DBG("skb->data[%d]=%x/n",i,skb->data[i]); } netif_rx_ni(skb); } static void mcp251x_hw_sleep(struct spi_device *spi) { // DBG("mcp251x_hw_sleep/n"); mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP); } static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb, struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); struct spi_device *spi = priv->spi; DBG("從應(yīng)用層收到發(fā)送命令/n"); if (priv->tx_skb || priv->tx_len) { dev_warn(&spi->dev, "hard_xmit called while tx busy/n"); return NETDEV_TX_BUSY; } if (can_dropped_invalid_skb(net, skb)) return NETDEV_TX_OK; netif_stop_queue(net); priv->tx_skb = skb; DBG("要發(fā)送的數(shù)據(jù)是skb/n"); DBG("啟動(dòng)發(fā)送隊(duì)列/n"); queue_work(priv->wq, &priv->tx_work); return NETDEV_TX_OK; } static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode) { struct mcp251x_priv *priv = netdev_priv(net); // DBG("mcp251x_do_set_mode/n"); switch (mode) { case CAN_MODE_START: mcp251x_clean(net); /* We have to delay work since SPI I/O may sleep */ priv->can.state = CAN_STATE_ERROR_ACTIVE; priv->restart_tx = 1; if (priv->can.restart_ms == 0) priv->after_suspend = AFTER_SUSPEND_RESTART; queue_work(priv->wq, &priv->restart_work); break; default: return -EOPNOTSUPP; } return 0; } static int mcp251x_set_normal_mode(struct spi_device *spi) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); unsigned long timeout; // DBG("mcp251x_set_normal_mode/n"); /* Enable interrupts */ intset=CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE | //CANINTF_MERRF | CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE; mcp251x_write_reg(spi, CANINTE,intset); if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { /* Put device into loopback mode */ mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK); } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) { /* Put device into listen-only mode */ mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY); } else { /* Put device into normal mode */ mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL); /* Wait for the device to enter normal mode */ timeout = jiffies + HZ; while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) { schedule(); if (time_after(jiffies, timeout)) { dev_err(&spi->dev, "MCP251x didn't" " enter in normal mode/n"); return -EBUSY; } } } priv->can.state = CAN_STATE_ERROR_ACTIVE; return 0; } static int mcp251x_do_set_bittiming(struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); struct can_bittiming *bt = &priv->can.bittiming; struct spi_device *spi = priv->spi; // DBG("mcp251x_do_set_bittiming/n"); mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) | (bt->brp - 1)); mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE | (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ? CNF2_SAM : 0) | ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) | (bt->prop_seg - 1)); mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK, (bt->phase_seg2 - 1)); dev_info(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x/n", mcp251x_read_reg(spi, CNF1), mcp251x_read_reg(spi, CNF2), mcp251x_read_reg(spi, CNF3)); return 0; } static int mcp251x_setup(struct net_device *net, struct mcp251x_priv *priv, struct spi_device *spi) { mcp251x_do_set_bittiming(net); // DBG("mcp251x_setup/n"); mcp251x_write_reg(spi, RXBCTRL(0), RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1); mcp251x_write_reg(spi, RXBCTRL(1), RXBCTRL_RXM0 | RXBCTRL_RXM1); return 0; } static int mcp251x_hw_reset(struct spi_device *spi) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); int ret; unsigned long timeout; // DBG("mcp251x_hw_reset/n"); priv->spi_tx_buf[0] = INSTRUCTION_RESET; ret = spi_write(spi, priv->spi_tx_buf, 1); if (ret) { dev_err(&spi->dev, "reset failed: ret = %d/n", ret); return -EIO; } /* Wait for reset to finish */ timeout = jiffies + HZ; mdelay(10); while ((mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) != CANCTRL_REQOP_CONF) { schedule(); if (time_after(jiffies, timeout)) { dev_err(&spi->dev, "MCP251x didn't" " enter in conf mode after reset/n"); return -EBUSY; } } return 0; } static int mcp251x_hw_probe(struct spi_device *spi) { int st1, st2; // DBG("mcp251x_hw_probe/n"); mcp251x_hw_reset(spi); /* * Please note that these are "magic values" based on after * reset defaults taken from data sheet which allows us to see * if we really have a chip on the bus (we avoid common all * zeroes or all ones situations) */ st1 = mcp251x_read_reg(spi, CANSTAT) & 0xEE; st2 = mcp251x_read_reg(spi, CANCTRL) & 0x17; dev_dbg(&spi->dev, "CANSTAT 0x%02x CANCTRL 0x%02x/n", st1, st2); /* Check for power up default values */ return (st1 == 0x80 && st2 == 0x07) ? 1 : 0; } static void mcp251x_open_clean(struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); struct spi_device *spi = priv->spi; struct mcp251x_platform_data *pdata = spi->dev.platform_data; DBG("mcp251x_open_clean/n"); free_irq(spi->irq, priv); mcp251x_hw_sleep(spi); if (pdata->transceiver_enable) pdata->transceiver_enable(0); close_candev(net); } static int mcp251x_stop(struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); struct spi_device *spi = priv->spi; struct mcp251x_platform_data *pdata = spi->dev.platform_data; DBG("mcp251x_stop/n"); close_candev(net); priv->force_quit = 1; free_irq(spi->irq, priv); destroy_workqueue(priv->wq); priv->wq = NULL; // del_timer(&check_timer); //刪除定時(shí)器 mutex_lock(&priv->mcp_lock); /* Disable and clear pending interrupts */ mcp251x_write_reg(spi, CANINTE, 0x00); mcp251x_write_reg(spi, CANINTF, 0x00); mcp251x_write_reg(spi, TXBCTRL(0), 0); mcp251x_clean(net); mcp251x_hw_sleep(spi); if (pdata->transceiver_enable) pdata->transceiver_enable(0); priv->can.state = CAN_STATE_STOPPED; mutex_unlock(&priv->mcp_lock); return 0; } static void mcp251x_error_skb(struct net_device *net, int can_id, int data1) { struct sk_buff *skb; struct can_frame *frame; DBG("mcp251x_error_skb/n"); skb = alloc_can_err_skb(net, &frame); if (skb) { frame->can_id |= can_id; frame->data[1] = data1; netif_rx_ni(skb); } else { dev_err(&net->dev, "cannot allocate error skb/n"); } } static void mcp251x_tx_work_handler(struct work_struct *ws) { DBG("進(jìn)入發(fā)送隊(duì)列/n"); struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, tx_work); struct spi_device *spi = priv->spi; struct net_device *net = priv->net; struct can_frame *frame; mutex_lock(&priv->mcp_lock); if (priv->tx_skb) { if (priv->can.state == CAN_STATE_BUS_OFF) { mcp251x_clean(net); } else { int i; DBG("打印skb里的數(shù)據(jù)/n"); for(i=0;i<20;i++) { DBG("priv->tx_skb->data[%d]=%x/n",i,priv->tx_skb->data[i]); } //將skb里的數(shù)據(jù)給can_frame以便組織發(fā)送 frame = (struct can_frame *)priv->tx_skb->data; DBG("打印can_frame的字段/n"); DBG(" frame->can_id=0x%x/n", frame->can_id); char *p=(char*)&(frame->can_id); for(i=0;i<4;i++) { DBG(" p=%x/n",*p); p++; } DBG(" frame->can_dlc=%d/n", frame->can_dlc); for(i=0;i<8;i++) { DBG(" frame->data[%d]=%x/n",i,frame->data[i]); } if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN) frame->can_dlc = CAN_FRAME_MAX_DATA_LEN; //發(fā)送 mcp251x_hw_tx(spi, frame, 0); priv->tx_len = 1 + frame->can_dlc; can_put_echo_skb(priv->tx_skb, net, 0); priv->tx_skb = NULL; } } mutex_unlock(&priv->mcp_lock); } static void mcp251x_restart_work_handler(struct work_struct *ws) { struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, restart_work); struct spi_device *spi = priv->spi; struct net_device *net = priv->net; DBG("mcp251x_restart_work_handler/n"); mutex_lock(&priv->mcp_lock); if (priv->after_suspend) { mdelay(10); mcp251x_hw_reset(spi); mcp251x_setup(net, priv, spi); if (priv->after_suspend & AFTER_SUSPEND_RESTART) { mcp251x_set_normal_mode(spi); } else if (priv->after_suspend & AFTER_SUSPEND_UP) { netif_device_attach(net); mcp251x_clean(net); mcp251x_set_normal_mode(spi); netif_wake_queue(net); } else { mcp251x_hw_sleep(spi); } priv->after_suspend = 0; priv->force_quit = 0; } if (priv->restart_tx) { priv->restart_tx = 0; mcp251x_write_reg(spi, TXBCTRL(0), 0); mcp251x_clean(net); netif_wake_queue(net); mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0); } mutex_unlock(&priv->mcp_lock); } /*static void check_timer_callback(unsigned long arg) { //DBG("timer clean CANINTF %X/n",arg); //int pin=gpio_get_value(S3C64XX_GPL(8)); // int pin=gpio_get_value(S3C64XX_GPN(5)); int pin=gpio_get_value(S3C64XX_GPL(8)); // DBG("timer pin=%d /n",pin); if(pin==0) { // struct mcp251x_priv *priv=(struct mcp251x_priv *)arg; // schedule_work(&(priv->irq_work)); DBG("timer schedule work/n"); } mod_timer(&check_timer,jiffies+8); //修改定時(shí)器 }*/ static irqreturn_t mcp251x_can_irq(int irq, void *dev_id) { DBG("有中斷產(chǎn)生/n"); struct mcp251x_priv *priv = dev_id; // struct spi_device *spi = priv->spi; // int pin=gpio_get_value(S3C64XX_GPL(8)); // DBG("pin=%d /n",pin); //DBG("before disable_irq_nosync(irq);/n"); disable_irq_nosync(irq); //disable_irq(irq); //DBG("after disable_irq_nosync(irq);/n"); //s3c_gpio_cfgpin(S3C64XX_GPL(8), S3C_GPIO_INPUT); //關(guān)中斷，為什么disable_irq死機(jī) //while(S3C_GPIO_INPUT!=s3c_gpio_getcfg(S3C64XX_GPL(8))); //schedule_work(&(priv->irq_work)); if (!work_pending(&priv->irq_work)) queue_work(priv->wq, &priv->irq_work); //enable_irq(irq); return IRQ_HANDLED; } /* static irqreturn_t mcp251x_can_irq(int irq, void *dev_id) { DBG("mcp251x_can_irq/n"); struct mcp251x_priv *priv = dev_id; // struct spi_device *spi = priv->spi; // int pin=gpio_get_value(S3C64XX_GPL(8)); // DBG("pin=%d /n",pin); //disable_irq_nosync(irq); s3c_gpio_cfgpin(S3C64XX_GPL(8), S3C_GPIO_INPUT); //關(guān)中斷，為什么disable_irq死機(jī) while(S3C_GPIO_INPUT!=s3c_gpio_getcfg(S3C64XX_GPL(8))); //schedule_work(&(priv->irq_work)); if (!work_pending(&priv->irq_work)) queue_work(priv->wq, &priv->irq_work); return IRQ_HANDLED; } */ void can_irq_work(struct work_struct *ws) { DBG("進(jìn)入中斷下半部/n"); struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, irq_work); struct spi_device *spi = priv->spi; struct net_device *net = priv->net; mutex_lock(&priv->mcp_lock); //mcp251x_write_reg(spi, CANINTE, (intset & (~ ( CANINTE_TX2IE) ))); while (!priv->force_quit) { enum can_state new_state; u8 intf, eflag; u8 clear_intf = 0; int can_id = 0, data1 = 0; mcp251x_read_2regs(spi, CANINTF, &intf, &eflag); //讀取中斷標(biāo)志寄存器，用于判斷是什么中斷 DBG("中斷標(biāo)志=0x%x/n",intf); //mcp251x_write_bits(spi, CANINTF, intf, 0x00); /* mask out flags we don't care about */ intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR ;//| CANINTF_MERRF; if (intf & CANINTF_TX) { DBG("是發(fā)送完成中斷: /n"); net->stats.tx_packets++; net->stats.tx_bytes += priv->tx_len - 1; if (priv->tx_len) { can_get_echo_skb(net, 0); priv->tx_len = 0; } netif_wake_queue(net); } /* receive buffer 1 */ if (intf & CANINTF_RX1IF) { DBG("是接收到數(shù)據(jù)中斷: /n"); DBG("receive buffer1有數(shù)據(jù)/n"); mcp251x_hw_rx(spi, 1); /* the MCP2515 does this automatically */ if (mcp251x_is_2510(spi)) clear_intf |= CANINTF_RX1IF; } /* receive buffer 0 */ if (intf & CANINTF_RX0IF) { DBG("是接收到數(shù)據(jù)中斷: /n"); DBG("receive buffer0有數(shù)據(jù)/n"); mcp251x_hw_rx(spi, 0); /* * Free one buffer ASAP * (The MCP2515 does this automatically.) */ if (mcp251x_is_2510(spi)) mcp251x_write_bits(spi, CANINTF, CANINTF_RX0IF, 0x00); } /* any error or tx interrupt we need to clear? */ if (intf & (CANINTF_ERR | CANINTF_TX)) clear_intf |= intf & (CANINTF_ERR | CANINTF_TX); if (clear_intf) mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00); if (eflag) mcp251x_write_bits(spi, EFLG, eflag, 0x00); /* Update can state */ if (eflag & EFLG_TXBO) { new_state = CAN_STATE_BUS_OFF; can_id |= CAN_ERR_BUSOFF; } else if (eflag & EFLG_TXEP) { new_state = CAN_STATE_ERROR_PASSIVE; can_id |= CAN_ERR_CRTL; data1 |= CAN_ERR_CRTL_TX_PASSIVE; } else if (eflag & EFLG_RXEP) { new_state = CAN_STATE_ERROR_PASSIVE; can_id |= CAN_ERR_CRTL; data1 |= CAN_ERR_CRTL_RX_PASSIVE; } else if (eflag & EFLG_TXWAR) { new_state = CAN_STATE_ERROR_WARNING; can_id |= CAN_ERR_CRTL; data1 |= CAN_ERR_CRTL_TX_WARNING; } else if (eflag & EFLG_RXWAR) { new_state = CAN_STATE_ERROR_WARNING; can_id |= CAN_ERR_CRTL; data1 |= CAN_ERR_CRTL_RX_WARNING; } else { new_state = CAN_STATE_ERROR_ACTIVE; } /* Update can state statistics */ switch (priv->can.state) { case CAN_STATE_ERROR_ACTIVE: if (new_state >= CAN_STATE_ERROR_WARNING && new_state <= CAN_STATE_BUS_OFF) priv->can.can_stats.error_warning++; case CAN_STATE_ERROR_WARNING: /* fallthrough */ if (new_state >= CAN_STATE_ERROR_PASSIVE && new_state <= CAN_STATE_BUS_OFF) priv->can.can_stats.error_passive++; break; default: break; } priv->can.state = new_state; if (intf & CANINTF_ERRIF) { /* Handle overflow counters */ if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) { if (eflag & EFLG_RX0OVR) { net->stats.rx_over_errors++; net->stats.rx_errors++; } if (eflag & EFLG_RX1OVR) { net->stats.rx_over_errors++; net->stats.rx_errors++; } can_id |= CAN_ERR_CRTL; data1 |= CAN_ERR_CRTL_RX_OVERFLOW; } mcp251x_error_skb(net, can_id, data1); } if (priv->can.state == CAN_STATE_BUS_OFF) { if (priv->can.restart_ms == 0) { priv->force_quit = 1; can_bus_off(net); mcp251x_hw_sleep(spi); break; } } if (intf == 0) break; } //mcp251x_write_reg(spi, CANINTE, intset); mutex_unlock(&priv->mcp_lock); enable_irq(spi->irq); //s3c_gpio_cfgpin(S3C64XX_GPL(8), S3C_GPIO_SFN(3)); //開中斷 } static int mcp251x_open(struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); struct spi_device *spi = priv->spi; struct mcp251x_platform_data *pdata = spi->dev.platform_data; int ret; // DBG("mcp251x_open/n"); DBG("mcp251x_open"); ret = open_candev(net); if (ret) { dev_err(&spi->dev, "unable to set initial baudrate!/n"); return ret; } mutex_lock(&priv->mcp_lock); if (pdata->transceiver_enable) pdata->transceiver_enable(1); priv->force_quit = 0; priv->tx_skb = NULL; priv->tx_len = 0; /* ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist, pdata->irq_flags ? pdata->irq_flags : IRQF_TRIGGER_FALLING, //IRQF_TRIGGER_LOW, // DEVICE_NAME, priv);*/ ret = request_irq(spi->irq, mcp251x_can_irq, //IRQF_TRIGGER_FALLING, /*IRQF_DISABLED |*/ IRQF_TRIGGER_LOW , //note by song DEVICE_NAME, priv); INIT_WORK(&priv->irq_work,can_irq_work); if (ret) { dev_err(&spi->dev, "failed to acquire irq %d/n", spi->irq); if (pdata->transceiver_enable) pdata->transceiver_enable(0); close_candev(net); goto open_unlock; } // init_timer(&check_timer); //初始化定時(shí)器 // check_timer.expires=jiffies+HZ; // check_timer.function=&check_timer_callback; // check_timer.data=(long)priv; //add_timer(&check_timer); //添加定時(shí)器*/ priv->wq = create_freezable_workqueue("mcp251x_wq"); //priv->wq = create_freezeable_workqueue("mcp251x_wq"); INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler); INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler); ret = mcp251x_hw_reset(spi); if (ret) { mcp251x_open_clean(net); goto open_unlock; } ret = mcp251x_setup(net, priv, spi); if (ret) { mcp251x_open_clean(net); goto open_unlock; } ret = mcp251x_set_normal_mode(spi); if (ret) { mcp251x_open_clean(net); goto open_unlock; } netif_wake_queue(net); open_unlock: mutex_unlock(&priv->mcp_lock); return ret; } static const struct net_device_ops mcp251x_netdev_ops = { .ndo_open = mcp251x_open, .ndo_stop = mcp251x_stop, .ndo_start_xmit = mcp251x_hard_start_xmit, }; static int __devinit mcp251x_can_probe(struct spi_device *spi) { struct net_device *net; struct mcp251x_priv *priv; struct mcp251x_platform_data *pdata = spi->dev.platform_data; int ret = -ENODEV; DBG("@@@@@@@@@@@@@@@@@@@@/n"); DBG("mcp251x_can_probe /n"); DBG("@@@@@@@@@@@@@@@@@@@@/n"); if (!pdata) /* Platform data is required for osc freq */ goto error_out; /* Allocate can/net device */ net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX); if (!net) { ret = -ENOMEM; goto error_alloc; } net->netdev_ops = &mcp251x_netdev_ops; net->flags |= IFF_ECHO; priv = netdev_priv(net); priv->can.bittiming_const = &mcp251x_bittiming_const; priv->can.do_set_mode = mcp251x_do_set_mode; priv->can.clock.freq = pdata->oscillator_frequency / 2; priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY; priv->model = spi_get_device_id(spi)->driver_data; priv->net = net; dev_set_drvdata(&spi->dev, priv); priv->spi = spi; mutex_init(&priv->mcp_lock); /* If requested, allocate DMA buffers */ if (mcp251x_enable_dma) { spi->dev.coherent_dma_mask = ~0; /* * Minimum coherent DMA allocation is PAGE_SIZE, so allocate * that much and share it between Tx and Rx DMA buffers. */ priv->spi_tx_buf = dma_alloc_coherent(&spi->dev, PAGE_SIZE, &priv->spi_tx_dma, GFP_DMA); if (priv->spi_tx_buf) { priv->spi_rx_buf = (u8 *)(priv->spi_tx_buf + (PAGE_SIZE / 2)); priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma + (PAGE_SIZE / 2)); } else { /* Fall back to non-DMA */ mcp251x_enable_dma = 0; } } /* Allocate non-DMA buffers */ if (!mcp251x_enable_dma) { priv->spi_tx_buf = kmalloc(SPI_TRANSFER_BUF_LEN, GFP_KERNEL); if (!priv->spi_tx_buf) { ret = -ENOMEM; goto error_tx_buf; } priv->spi_rx_buf = kmalloc(SPI_TRANSFER_BUF_LEN, GFP_KERNEL); if (!priv->spi_rx_buf) { ret = -ENOMEM; goto error_rx_buf; } } if (pdata->power_enable) pdata->power_enable(1); /* Call out to platform specific setup */ if (pdata->board_specific_setup) pdata->board_specific_setup(spi); SET_NETDEV_DEV(net, &spi->dev); /* Configure the SPI bus */ spi->mode = SPI_MODE_0; spi->bits_per_Word = 8; spi_setup(spi); /* Here is OK to not lock the MCP, no one knows about it yet */ if (!mcp251x_hw_probe(spi)) { dev_info(&spi->dev, "Probe failed/n"); goto error_probe; } mcp251x_hw_sleep(spi); if (pdata->transceiver_enable) pdata->transceiver_enable(0); ret = register_candev(net); DBG("@@@@@@@@@@@@@@@@@@@@/n"); DBG("register_candev ret = %d/n",ret); DBG("@@@@@@@@@@@@@@@@@@@@/n"); if (!ret) { dev_info(&spi->dev, "probed/n"); return ret; } error_probe: if (!mcp251x_enable_dma) kfree(priv->spi_rx_buf); error_rx_buf: if (!mcp251x_enable_dma) kfree(priv->spi_tx_buf); error_tx_buf: free_candev(net); if (mcp251x_enable_dma) dma_free_coherent(&spi->dev, PAGE_SIZE, priv->spi_tx_buf, priv->spi_tx_dma); error_alloc: if (pdata->power_enable) pdata->power_enable(0); dev_err(&spi->dev, "probe failed/n"); error_out: return ret; } static int __devexit mcp251x_can_remove(struct spi_device *spi) { struct mcp251x_platform_data *pdata = spi->dev.platform_data; struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); struct net_device *net = priv->net; DBG("mcp251x_can_remove/n"); unregister_candev(net); free_candev(net); if (mcp251x_enable_dma) { dma_free_coherent(&spi->dev, PAGE_SIZE, priv->spi_tx_buf, priv->spi_tx_dma); } else { kfree(priv->spi_tx_buf); kfree(priv->spi_rx_buf); } if (pdata->power_enable) pdata->power_enable(0); return 0; } #ifdef CONFIG_PM static int mcp251x_can_suspend(struct spi_device *spi, pm_message_t state) { struct mcp251x_platform_data *pdata = spi->dev.platform_data; struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); struct net_device *net = priv->net; DBG("mcp251x_can_suspend/n"); priv->force_quit = 1; disable_irq(spi->irq); /* * Note: at this point neither IST nor workqueues are running. * open/stop cannot be called anyway so locking is not needed */ if (netif_running(net)) { netif_device_detach(net); mcp251x_hw_sleep(spi); if (pdata->transceiver_enable) pdata->transceiver_enable(0); priv->after_suspend = AFTER_SUSPEND_UP; } else { priv->after_suspend = AFTER_SUSPEND_DOWN; } if (pdata->power_enable) { pdata->power_enable(0); priv->after_suspend |= AFTER_SUSPEND_POWER; } return 0; } static int mcp251x_can_resume(struct spi_device *spi) { DBG("mcp251x_can_resume/n"); struct mcp251x_platform_data *pdata = spi->dev.platform_data; struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); if (priv->after_suspend & AFTER_SUSPEND_POWER) { pdata->power_enable(1); queue_work(priv->wq, &priv->restart_work); } else { if (priv->after_suspend & AFTER_SUSPEND_UP) { if (pdata->transceiver_enable) pdata->transceiver_enable(1); queue_work(priv->wq, &priv->restart_work); } else { priv->after_suspend = 0; } } priv->force_quit = 0; enable_irq(spi->irq); return 0; } #else #define mcp251x_can_suspend NULL #define mcp251x_can_resume NULL #endif static const struct spi_device_id mcp251x_id_table[] = { { "mcp2510", CAN_MCP251X_MCP2510 }, { "mcp2515", CAN_MCP251X_MCP2515 }, { }, }; MODULE_DEVICE_TABLE(spi, mcp251x_id_table); static struct spi_driver mcp251x_can_driver = { .driver = { .name = DEVICE_NAME, .bus = &spi_bus_type, .owner = THIS_MODULE, }, .id_table = mcp251x_id_table, .probe = mcp251x_can_probe, .remove = __devexit_p(mcp251x_can_remove), .suspend = mcp251x_can_suspend, .resume = mcp251x_can_resume, }; static int __init mcp251x_can_init(void) { DBG("init/n"); return spi_register_driver(&mcp251x_can_driver); } static void __exit mcp251x_can_exit(void) { DBG("exit/n"); spi_unregister_driver(&mcp251x_can_driver); } module_init(mcp251x_can_init); module_exit(mcp251x_can_exit); MODULE_AUTHOR("Chris Elston <celston@katalix.com>, " "Christian Pellegrin <chripell@evolware.org>"); MODULE_DESCRIPTION("Microchip 251x CAN driver"); MODULE_LICENSE("GPL v2");

******************************************************************幾個(gè)疑點(diǎn)分析----以下討論適用于te6410中斷注冊(cè)

static inline int __must_check request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *name, void *dev) { return request_threaded_irq(irq, handler, NULL, flags, name, dev); }

原來他調(diào)用了request_threaded_irq(),并將中斷處理函數(shù)(上半部)handler作為參數(shù)傳遞過去。追蹤到request_threaded_irq，如下

int request_threaded_irq(unsigned int irq, irq_handler_t handler, irq_handler_t thread_fn, unsigned long irqflags, const char *devname, void *dev_id)

其中要注意的兩個(gè)參數(shù)，irq_handler_t handler，中斷處理函數(shù)上半部irq_handler_t thread_fn，中斷線程化~~，這樣直接實(shí)現(xiàn)了中斷處理函數(shù)的下半部，不必自己再去使用工作隊(duì)列實(shí)現(xiàn)下半部了~~/*附工作隊(duì)列的實(shí)現(xiàn)創(chuàng)建工作隊(duì)列，并加入到一個(gè)工作者線程里讓其去執(zhí)行。這個(gè)工作者線程可以使內(nèi)核現(xiàn)成的，也可以使自己心創(chuàng)建的。創(chuàng)建一個(gè)工作隊(duì)列work_struct，使用DECLARE_WORK靜態(tài)創(chuàng)建一個(gè)工作隊(duì)列，參數(shù)包括隊(duì)列名稱和隊(duì)列函數(shù)，也可使用INIT_WORK動(dòng)態(tài)創(chuàng)建。創(chuàng)建一個(gè)新的工作者線程workqueue_struct,使用create_workqueue，返回值是工作者線程指針。將工作隊(duì)列放到指定的工作者線程中去執(zhí)行，int queue_work(struct workqueue_struct *wq, struct work_struct *work)將工作隊(duì)列放到系統(tǒng)已有的events工作者線程中去執(zhí)行，直接調(diào)用sheldule_work(&work)即可。工作者線程是一個(gè)內(nèi)核線程，運(yùn)行在進(jìn)程上下文。工作者線程被喚醒時(shí)，會(huì)依次執(zhí)行它里面的工作隊(duì)列----組成了一個(gè)鏈表。*/搜索2.6.32.2源碼，只發(fā)現(xiàn)一個(gè)同時(shí)使用了這兩個(gè)參數(shù)的例子Broadcom B43 wireless driver,位于dribers/net/wireless/b43/main.c

err = request_threaded_irq(dev->dev->irq, b43_interrupt_handler, b43_interrupt_thread_handler, IRQF_SHARED, KBUILD_MODNAME, dev);

其在中斷上半部b43_interrupt_handler里禁止中斷，在中斷下半部b43_interrupt_thread_handler里批量讀取數(shù)據(jù)然后重新使能中斷(如果要清除中斷標(biāo)志位，則在使能之前先清除一下)。其余的例子幾乎都只使用了一個(gè)參數(shù)thread_fn，而handler置為NULL,比如mcs5000_ts.c - Touchscreen driver for MELFAS MCS-5000 controller

ret = request_threaded_irq(client->irq, NULL, mcs5000_ts_interrupt, IRQF_TRIGGER_LOW | IRQF_ONESHOT, "mcs5000_ts", data);

又如本文要討論的 mcp251x.c - CAN bus driver for Microchip 251x CAN Controller with SPI Interface

ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist, IRQF_TRIGGER_FALLING, DEVICE_NAME, priv);

中斷觸發(fā)使用IRQF_TRIGGER_FALLING作為中斷觸發(fā)的條件。而mcp2515則是只要有數(shù)據(jù)發(fā)送完成(發(fā)給can總線)或有新的數(shù)據(jù)到來(來自can總線)就會(huì)置int引腳低電平，此腳接到0k6410的eint16，向ok6410發(fā)送中斷中斷信號(hào)。MCP2515有八個(gè)中斷源。CANINTE寄存器包含了使能各中斷源的中斷使能位。 CANINTF 寄存器包含了各中斷源的中斷標(biāo)志位。當(dāng)發(fā)生中斷時(shí)，INT 引腳將被MCP2515拉為低電平，并保持低電平狀態(tài)直至MCU清除中斷。中斷只有在引起相應(yīng)中斷的條件消失后，才會(huì)被清除。mcp2515會(huì)自動(dòng)清除中斷嗎？說明書上沒寫自動(dòng)清除。mcp251x.c中卻認(rèn)為可以自動(dòng)清除？如果使用低電平觸發(fā)，則須存在中斷上半部，在上半部里面先disable此中斷，然后在下半部里面?zhèn)鬏斖陻?shù)據(jù)之后再enable此中斷。如果不在上半部disable此中斷，則由于低電平一直存在，就會(huì)一直觸發(fā)中斷，從而一直執(zhí)行中斷上半部，(下半部根本就沒機(jī)會(huì)執(zhí)行到)，造成死機(jī)。如果使用低電平觸發(fā)，如果中斷上半部函數(shù)指針設(shè)為NULL，那么即使在中斷下半部執(zhí)行disable此中斷，也會(huì)造成死機(jī)。因?yàn)橹袛喟l(fā)生時(shí)，不會(huì)立即執(zhí)行下半部函數(shù)，所以有可能沒及時(shí)禁掉此中斷，造成中斷(此時(shí)仍然低電平)繼續(xù)觸發(fā)而使下半部線程大量重復(fù)的創(chuàng)建(或許)造成死機(jī)。如果使用下降沿觸發(fā)，可以不存在上半部，即上半部函數(shù)指針可設(shè)為NULL，在下半部中可以先disable此中斷，然后讀取數(shù)據(jù)再清除中斷標(biāo)志位******************************************************************refer tolkd2http://blog.csdn.net/zhangjie201412/article/details/7067448

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