can: Driver for the Microchip MCP251x SPI CAN controllers
Christian Pellegrin [Mon, 2 Nov 2009 23:07:00 +0000 (23:07 +0000)]
Signed-off-by: Christian Pellegrin <chripell@fsfe.org>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/can/Kconfig
drivers/net/can/Makefile
drivers/net/can/mcp251x.c [new file with mode: 0644]
include/linux/can/platform/mcp251x.h [new file with mode: 0644]

index 26d77cc..b819cc2 100644 (file)
@@ -102,6 +102,12 @@ config CAN_TI_HECC
          Driver for TI HECC (High End CAN Controller) module found on many
          TI devices. The device specifications are available from www.ti.com
 
+config CAN_MCP251X
+       tristate "Microchip MCP251x SPI CAN controllers"
+       depends on CAN_DEV && SPI
+       ---help---
+         Driver for the Microchip MCP251x SPI CAN controllers.
+
 config CAN_DEBUG_DEVICES
        bool "CAN devices debugging messages"
        depends on CAN
index 31f4ab5..1489181 100644 (file)
@@ -12,5 +12,6 @@ obj-y                         += usb/
 obj-$(CONFIG_CAN_SJA1000)      += sja1000/
 obj-$(CONFIG_CAN_AT91)         += at91_can.o
 obj-$(CONFIG_CAN_TI_HECC)      += ti_hecc.o
+obj-$(CONFIG_CAN_MCP251X)      += mcp251x.o
 
 ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/mcp251x.c b/drivers/net/can/mcp251x.c
new file mode 100644 (file)
index 0000000..8f48f4b
--- /dev/null
@@ -0,0 +1,1164 @@
+/*
+ * 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,
+ *         .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 <linux/can.h>
+#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/spi/spi.h>
+#include <linux/uaccess.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 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 = buf[RXBDLC_OFF] & RXBDLC_LEN_MASK;
+               if (len > 8)
+                       len = 8;
+               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 = buf[RXBDLC_OFF] & RXBDLC_LEN_MASK;
+       if (frame->can_dlc > 8) {
+               dev_warn(&spi->dev, "invalid frame recevied\n");
+               priv->net->stats.rx_errors++;
+               dev_kfree_skb(skb);
+               return;
+       }
+       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 (skb->len != sizeof(struct can_frame)) {
+               dev_err(&spi->dev, "dropping packet - bad length\n");
+               dev_kfree_skb(skb);
+               net->stats.tx_dropped++;
+               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)
+{
+       int ret;
+
+       ret = open_candev(net);
+       if (ret) {
+               dev_err(&spi->dev, "unable to set initial baudrate!\n");
+               return ret;
+       }
+
+       /* 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;
+
+       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);
+               return ret;
+       }
+
+       mcp251x_hw_wakeup(spi);
+       mcp251x_hw_reset(spi);
+       ret = mcp251x_setup(net, priv, spi);
+       if (ret) {
+               free_irq(spi->irq, net);
+               if (pdata->transceiver_enable)
+                       pdata->transceiver_enable(0);
+               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->can.do_set_bittiming = mcp251x_do_set_bittiming;
+       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_tx_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 <celston@katalix.com>, "
+             "Christian Pellegrin <chripell@evolware.org>");
+MODULE_DESCRIPTION("Microchip 251x CAN driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/can/platform/mcp251x.h b/include/linux/can/platform/mcp251x.h
new file mode 100644 (file)
index 0000000..1448177
--- /dev/null
@@ -0,0 +1,36 @@
+#ifndef __CAN_PLATFORM_MCP251X_H__
+#define __CAN_PLATFORM_MCP251X_H__
+
+/*
+ *
+ * CAN bus driver for Microchip 251x CAN Controller with SPI Interface
+ *
+ */
+
+#include <linux/spi/spi.h>
+
+/**
+ * struct mcp251x_platform_data - MCP251X SPI CAN controller platform data
+ * @oscillator_frequency:       - oscillator frequency in Hz
+ * @model:                      - actual type of chip
+ * @board_specific_setup:       - called before probing the chip (power,reset)
+ * @transceiver_enable:         - called to power on/off the transceiver
+ * @power_enable:               - called to power on/off the mcp *and* the
+ *                                transceiver
+ *
+ * Please note that you should define power_enable or transceiver_enable or
+ * none of them. Defining both of them is no use.
+ *
+ */
+
+struct mcp251x_platform_data {
+       unsigned long oscillator_frequency;
+       int model;
+#define CAN_MCP251X_MCP2510 0
+#define CAN_MCP251X_MCP2515 1
+       int (*board_specific_setup)(struct spi_device *spi);
+       int (*transceiver_enable)(int enable);
+       int (*power_enable) (int enable);
+};
+
+#endif /* __CAN_PLATFORM_MCP251X_H__ */