/* * CAN bus driver for Microchip 251x CAN Controller with SPI Interface * * MCP2510 support and bug fixes by Christian Pellegrin * * * 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, * .model = CAN_MCP251X_MCP2510, * .power_enable = mcp251x_power_enable, * .transceiver_enable = NULL, * }; * * static struct spi_board_info spi_board_info[] = { * { * .modalias = "mcp251x", * .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. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* 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 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_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 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 "mcp251x" 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, }; struct mcp251x_priv { struct can_priv can; struct net_device *net; struct spi_device *spi; struct mutex spi_lock; /* SPI buffer 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 irq_work; struct completion awake; int wake; 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; }; static void mcp251x_clean(struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); 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; 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); if (ret) dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret); 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; mutex_lock(&priv->spi_lock); priv->spi_tx_buf[0] = INSTRUCTION_READ; priv->spi_tx_buf[1] = reg; mcp251x_spi_trans(spi, 3); val = priv->spi_rx_buf[2]; mutex_unlock(&priv->spi_lock); return val; } static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); mutex_lock(&priv->spi_lock); priv->spi_tx_buf[0] = INSTRUCTION_WRITE; priv->spi_tx_buf[1] = reg; priv->spi_tx_buf[2] = val; mcp251x_spi_trans(spi, 3); mutex_unlock(&priv->spi_lock); } 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); mutex_lock(&priv->spi_lock); 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); mutex_unlock(&priv->spi_lock); } static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf, int len, int tx_buf_idx) { struct mcp251x_platform_data *pdata = spi->dev.platform_data; struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); if (pdata->model == CAN_MCP251X_MCP2510) { int i; for (i = 1; i < TXBDAT_OFF + len; i++) mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i, buf[i]); } else { mutex_lock(&priv->spi_lock); memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len); mcp251x_spi_trans(spi, TXBDAT_OFF + len); mutex_unlock(&priv->spi_lock); } } 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 */ if (exide) sid = (frame->can_id & CAN_EFF_MASK) >> 18; else sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */ eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */ rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */ 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); mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx); mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx), TXBCTRL_TXREQ); } static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf, int buf_idx) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); struct mcp251x_platform_data *pdata = spi->dev.platform_data; if (pdata->model == CAN_MCP251X_MCP2510) { 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 { mutex_lock(&priv->spi_lock); priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx); mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN); memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN); mutex_unlock(&priv->spi_lock); } } 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]; 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); if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) { /* 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 { /* Standard ID format */ frame->can_id = (buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) | (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT); } /* Data length */ frame->can_dlc = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK); memcpy(frame->data, buf + RXBDAT_OFF, frame->can_dlc); priv->net->stats.rx_packets++; priv->net->stats.rx_bytes += frame->can_dlc; netif_rx(skb); } static void mcp251x_hw_sleep(struct spi_device *spi) { mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP); } static void mcp251x_hw_wakeup(struct spi_device *spi) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); priv->wake = 1; /* Can only wake up by generating a wake-up interrupt. */ mcp251x_write_bits(spi, CANINTE, CANINTE_WAKIE, CANINTE_WAKIE); mcp251x_write_bits(spi, CANINTF, CANINTF_WAKIF, CANINTF_WAKIF); /* Wait until the device is awake */ if (!wait_for_completion_timeout(&priv->awake, HZ)) dev_err(&spi->dev, "MCP251x didn't wake-up\n"); } 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; if (priv->tx_skb || priv->tx_len) { dev_warn(&spi->dev, "hard_xmit called while tx busy\n"); netif_stop_queue(net); return NETDEV_TX_BUSY; } if (can_dropped_invalid_skb(net, skb)) return NETDEV_TX_OK; netif_stop_queue(net); priv->tx_skb = skb; net->trans_start = jiffies; 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); switch (mode) { case CAN_MODE_START: /* 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->irq_work); break; default: return -EOPNOTSUPP; } return 0; } static void mcp251x_set_normal_mode(struct spi_device *spi) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); unsigned long timeout; /* Enable interrupts */ mcp251x_write_reg(spi, CANINTE, CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE | CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE | CANINTF_MERRF); if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { /* Put device into loopback mode */ mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK); } 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; } } } priv->can.state = CAN_STATE_ERROR_ACTIVE; } 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; 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); /* Enable RX0->RX1 buffer roll over and disable filters */ mcp251x_write_bits(spi, RXBCTRL(0), RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1, RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1); mcp251x_write_bits(spi, RXBCTRL(1), RXBCTRL_RXM0 | RXBCTRL_RXM1, RXBCTRL_RXM0 | RXBCTRL_RXM1); return 0; } static void mcp251x_hw_reset(struct spi_device *spi) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); int ret; mutex_lock(&priv->spi_lock); priv->spi_tx_buf[0] = INSTRUCTION_RESET; ret = spi_write(spi, priv->spi_tx_buf, 1); mutex_unlock(&priv->spi_lock); if (ret) dev_err(&spi->dev, "reset failed: ret = %d\n", ret); /* Wait for reset to finish */ mdelay(10); } static int mcp251x_hw_probe(struct spi_device *spi) { int st1, st2; 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 irqreturn_t mcp251x_can_isr(int irq, void *dev_id) { struct net_device *net = (struct net_device *)dev_id; struct mcp251x_priv *priv = netdev_priv(net); /* Schedule bottom half */ if (!work_pending(&priv->irq_work)) queue_work(priv->wq, &priv->irq_work); return IRQ_HANDLED; } 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; ret = open_candev(net); if (ret) { dev_err(&spi->dev, "unable to set initial baudrate!\n"); return ret; } if (pdata->transceiver_enable) pdata->transceiver_enable(1); priv->force_quit = 0; priv->tx_skb = NULL; priv->tx_len = 0; ret = request_irq(spi->irq, mcp251x_can_isr, IRQF_TRIGGER_FALLING, DEVICE_NAME, net); 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); return ret; } mcp251x_hw_wakeup(spi); mcp251x_hw_reset(spi); ret = mcp251x_setup(net, priv, spi); if (ret) { free_irq(spi->irq, net); mcp251x_hw_sleep(spi); if (pdata->transceiver_enable) pdata->transceiver_enable(0); close_candev(net); return ret; } mcp251x_set_normal_mode(spi); netif_wake_queue(net); return 0; } 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; close_candev(net); /* Disable and clear pending interrupts */ mcp251x_write_reg(spi, CANINTE, 0x00); mcp251x_write_reg(spi, CANINTF, 0x00); priv->force_quit = 1; free_irq(spi->irq, net); flush_workqueue(priv->wq); mcp251x_write_reg(spi, TXBCTRL(0), 0); if (priv->tx_skb || priv->tx_len) mcp251x_clean(net); mcp251x_hw_sleep(spi); if (pdata->transceiver_enable) pdata->transceiver_enable(0); priv->can.state = CAN_STATE_STOPPED; return 0; } 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; if (priv->tx_skb) { frame = (struct can_frame *)priv->tx_skb->data; if (priv->can.state == CAN_STATE_BUS_OFF) { mcp251x_clean(net); netif_wake_queue(net); return; } 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; } } static void mcp251x_irq_work_handler(struct work_struct *ws) { struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, irq_work); struct spi_device *spi = priv->spi; struct net_device *net = priv->net; u8 txbnctrl; u8 intf; enum can_state new_state; 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); /* Clean since we lost tx buffer */ if (priv->tx_skb || priv->tx_len) { mcp251x_clean(net); netif_wake_queue(net); } mcp251x_set_normal_mode(spi); } else { mcp251x_hw_sleep(spi); } priv->after_suspend = 0; } if (priv->can.restart_ms == 0 && priv->can.state == CAN_STATE_BUS_OFF) return; while (!priv->force_quit && !freezing(current)) { u8 eflag = mcp251x_read_reg(spi, EFLG); int can_id = 0, data1 = 0; mcp251x_write_reg(spi, EFLG, 0x00); if (priv->restart_tx) { priv->restart_tx = 0; mcp251x_write_reg(spi, TXBCTRL(0), 0); if (priv->tx_skb || priv->tx_len) mcp251x_clean(net); netif_wake_queue(net); can_id |= CAN_ERR_RESTARTED; } if (priv->wake) { /* Wait whilst the device wakes up */ mdelay(10); priv->wake = 0; } intf = mcp251x_read_reg(spi, CANINTF); mcp251x_write_bits(spi, CANINTF, intf, 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) || (can_id & CAN_ERR_RESTARTED)) { struct sk_buff *skb; struct can_frame *frame; /* Create error frame */ skb = alloc_can_err_skb(net, &frame); if (skb) { /* Set error frame flags based on bus state */ frame->can_id = can_id; frame->data[1] = data1; /* Update net stats for overflows */ if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) { if (eflag & EFLG_RX0OVR) net->stats.rx_over_errors++; if (eflag & EFLG_RX1OVR) net->stats.rx_over_errors++; frame->can_id |= CAN_ERR_CRTL; frame->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW; } netif_rx(skb); } else { dev_info(&spi->dev, "cannot allocate error skb\n"); } } if (priv->can.state == CAN_STATE_BUS_OFF) { if (priv->can.restart_ms == 0) { can_bus_off(net); mcp251x_hw_sleep(spi); return; } } if (intf == 0) break; if (intf & CANINTF_WAKIF) complete(&priv->awake); if (intf & CANINTF_MERRF) { /* If there are pending Tx buffers, restart queue */ txbnctrl = mcp251x_read_reg(spi, TXBCTRL(0)); if (!(txbnctrl & TXBCTRL_TXREQ)) { if (priv->tx_skb || priv->tx_len) mcp251x_clean(net); netif_wake_queue(net); } } if (intf & (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)) { 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); } if (intf & CANINTF_RX0IF) mcp251x_hw_rx(spi, 0); if (intf & CANINTF_RX1IF) mcp251x_hw_rx(spi, 1); } } 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; 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->net = net; dev_set_drvdata(&spi->dev, priv); priv->spi = spi; mutex_init(&priv->spi_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); priv->wq = create_freezeable_workqueue("mcp251x_wq"); INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler); INIT_WORK(&priv->irq_work, mcp251x_irq_work_handler); init_completion(&priv->awake); /* Configure the SPI bus */ spi->mode = SPI_MODE_0; spi->bits_per_word = 8; spi_setup(spi); 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); 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; unregister_candev(net); free_candev(net); priv->force_quit = 1; flush_workqueue(priv->wq); destroy_workqueue(priv->wq); 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; 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) { 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->irq_work); } else { if (priv->after_suspend & AFTER_SUSPEND_UP) { if (pdata->transceiver_enable) pdata->transceiver_enable(1); queue_work(priv->wq, &priv->irq_work); } else { priv->after_suspend = 0; } } return 0; } #else #define mcp251x_can_suspend NULL #define mcp251x_can_resume NULL #endif static struct spi_driver mcp251x_can_driver = { .driver = { .name = DEVICE_NAME, .bus = &spi_bus_type, .owner = THIS_MODULE, }, .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) { return spi_register_driver(&mcp251x_can_driver); } static void __exit mcp251x_can_exit(void) { spi_unregister_driver(&mcp251x_can_driver); } module_init(mcp251x_can_init); module_exit(mcp251x_can_exit); MODULE_AUTHOR("Chris Elston , " "Christian Pellegrin "); MODULE_DESCRIPTION("Microchip 251x CAN driver"); MODULE_LICENSE("GPL v2");