Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / can / cc770 / cc770.c
diff --git a/kernel/drivers/net/can/cc770/cc770.c b/kernel/drivers/net/can/cc770/cc770.c
new file mode 100644 (file)
index 0000000..c11d449
--- /dev/null
@@ -0,0 +1,884 @@
+/*
+ * Core driver for the CC770 and AN82527 CAN controllers
+ *
+ * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/skbuff.h>
+#include <linux/delay.h>
+
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/error.h>
+#include <linux/can/platform/cc770.h>
+
+#include "cc770.h"
+
+MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver");
+
+/*
+ * The CC770 is a CAN controller from Bosch, which is 100% compatible
+ * with the AN82527 from Intel, but with "bugs" being fixed and some
+ * additional functionality, mainly:
+ *
+ * 1. RX and TX error counters are readable.
+ * 2. Support of silent (listen-only) mode.
+ * 3. Message object 15 can receive all types of frames, also RTR and EFF.
+ *
+ * Details are available from Bosch's "CC770_Product_Info_2007-01.pdf",
+ * which explains in detail the compatibility between the CC770 and the
+ * 82527. This driver use the additional functionality 3. on real CC770
+ * devices. Unfortunately, the CC770 does still not store the message
+ * identifier of received remote transmission request frames and
+ * therefore it's set to 0.
+ *
+ * The message objects 1..14 can be used for TX and RX while the message
+ * objects 15 is optimized for RX. It has a shadow register for reliable
+ * data reception under heavy bus load. Therefore it makes sense to use
+ * this message object for the needed use case. The frame type (EFF/SFF)
+ * for the message object 15 can be defined via kernel module parameter
+ * "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames,
+ * otherwise 11 bit SFF messages.
+ */
+static int msgobj15_eff;
+module_param(msgobj15_eff, int, S_IRUGO);
+MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
+                "(default: 11-bit standard frames)");
+
+static int i82527_compat;
+module_param(i82527_compat, int, S_IRUGO);
+MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 comptibility mode "
+                "without using additional functions");
+
+/*
+ * This driver uses the last 5 message objects 11..15. The definitions
+ * and structure below allows to configure and assign them to the real
+ * message object.
+ */
+static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = {
+       [CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX,
+       [CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF,
+       [CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR,
+       [CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR |
+                             CC770_OBJ_FLAG_EFF,
+       [CC770_OBJ_TX] = 0,
+};
+
+static const struct can_bittiming_const cc770_bittiming_const = {
+       .name = KBUILD_MODNAME,
+       .tseg1_min = 1,
+       .tseg1_max = 16,
+       .tseg2_min = 1,
+       .tseg2_max = 8,
+       .sjw_max = 4,
+       .brp_min = 1,
+       .brp_max = 64,
+       .brp_inc = 1,
+};
+
+static inline int intid2obj(unsigned int intid)
+{
+       if (intid == 2)
+               return 0;
+       else
+               return MSGOBJ_LAST + 2 - intid;
+}
+
+static void enable_all_objs(const struct net_device *dev)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       u8 msgcfg;
+       unsigned char obj_flags;
+       unsigned int o, mo;
+
+       for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
+               obj_flags = priv->obj_flags[o];
+               mo = obj2msgobj(o);
+
+               if (obj_flags & CC770_OBJ_FLAG_RX) {
+                       /*
+                        * We don't need extra objects for RTR and EFF if
+                        * the additional CC770 functions are enabled.
+                        */
+                       if (priv->control_normal_mode & CTRL_EAF) {
+                               if (o > 0)
+                                       continue;
+                               netdev_dbg(dev, "Message object %d for "
+                                          "RX data, RTR, SFF and EFF\n", mo);
+                       } else {
+                               netdev_dbg(dev,
+                                          "Message object %d for RX %s %s\n",
+                                          mo, obj_flags & CC770_OBJ_FLAG_RTR ?
+                                          "RTR" : "data",
+                                          obj_flags & CC770_OBJ_FLAG_EFF ?
+                                          "EFF" : "SFF");
+                       }
+
+                       if (obj_flags & CC770_OBJ_FLAG_EFF)
+                               msgcfg = MSGCFG_XTD;
+                       else
+                               msgcfg = 0;
+                       if (obj_flags & CC770_OBJ_FLAG_RTR)
+                               msgcfg |= MSGCFG_DIR;
+
+                       cc770_write_reg(priv, msgobj[mo].config, msgcfg);
+                       cc770_write_reg(priv, msgobj[mo].ctrl0,
+                                       MSGVAL_SET | TXIE_RES |
+                                       RXIE_SET | INTPND_RES);
+
+                       if (obj_flags & CC770_OBJ_FLAG_RTR)
+                               cc770_write_reg(priv, msgobj[mo].ctrl1,
+                                               NEWDAT_RES | CPUUPD_SET |
+                                               TXRQST_RES | RMTPND_RES);
+                       else
+                               cc770_write_reg(priv, msgobj[mo].ctrl1,
+                                               NEWDAT_RES | MSGLST_RES |
+                                               TXRQST_RES | RMTPND_RES);
+               } else {
+                       netdev_dbg(dev, "Message object %d for "
+                                  "TX data, RTR, SFF and EFF\n", mo);
+
+                       cc770_write_reg(priv, msgobj[mo].ctrl1,
+                                       RMTPND_RES | TXRQST_RES |
+                                       CPUUPD_RES | NEWDAT_RES);
+                       cc770_write_reg(priv, msgobj[mo].ctrl0,
+                                       MSGVAL_RES | TXIE_RES |
+                                       RXIE_RES | INTPND_RES);
+               }
+       }
+}
+
+static void disable_all_objs(const struct cc770_priv *priv)
+{
+       int o, mo;
+
+       for (o = 0; o <  ARRAY_SIZE(priv->obj_flags); o++) {
+               mo = obj2msgobj(o);
+
+               if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) {
+                       if (o > 0 && priv->control_normal_mode & CTRL_EAF)
+                               continue;
+
+                       cc770_write_reg(priv, msgobj[mo].ctrl1,
+                                       NEWDAT_RES | MSGLST_RES |
+                                       TXRQST_RES | RMTPND_RES);
+                       cc770_write_reg(priv, msgobj[mo].ctrl0,
+                                       MSGVAL_RES | TXIE_RES |
+                                       RXIE_RES | INTPND_RES);
+               } else {
+                       /* Clear message object for send */
+                       cc770_write_reg(priv, msgobj[mo].ctrl1,
+                                       RMTPND_RES | TXRQST_RES |
+                                       CPUUPD_RES | NEWDAT_RES);
+                       cc770_write_reg(priv, msgobj[mo].ctrl0,
+                                       MSGVAL_RES | TXIE_RES |
+                                       RXIE_RES | INTPND_RES);
+               }
+       }
+}
+
+static void set_reset_mode(struct net_device *dev)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+
+       /* Enable configuration and puts chip in bus-off, disable interrupts */
+       cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI);
+
+       priv->can.state = CAN_STATE_STOPPED;
+
+       /* Clear interrupts */
+       cc770_read_reg(priv, interrupt);
+
+       /* Clear status register */
+       cc770_write_reg(priv, status, 0);
+
+       /* Disable all used message objects */
+       disable_all_objs(priv);
+}
+
+static void set_normal_mode(struct net_device *dev)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+
+       /* Clear interrupts */
+       cc770_read_reg(priv, interrupt);
+
+       /* Clear status register and pre-set last error code */
+       cc770_write_reg(priv, status, STAT_LEC_MASK);
+
+       /* Enable all used message objects*/
+       enable_all_objs(dev);
+
+       /*
+        * Clear bus-off, interrupts only for errors,
+        * not for status change
+        */
+       cc770_write_reg(priv, control, priv->control_normal_mode);
+
+       priv->can.state = CAN_STATE_ERROR_ACTIVE;
+}
+
+static void chipset_init(struct cc770_priv *priv)
+{
+       int mo, id, data;
+
+       /* Enable configuration and put chip in bus-off, disable interrupts */
+       cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI));
+
+       /* Set CLKOUT divider and slew rates */
+       cc770_write_reg(priv, clkout, priv->clkout);
+
+       /* Configure CPU interface / CLKOUT enable */
+       cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
+
+       /* Set bus configuration  */
+       cc770_write_reg(priv, bus_config, priv->bus_config);
+
+       /* Clear interrupts */
+       cc770_read_reg(priv, interrupt);
+
+       /* Clear status register */
+       cc770_write_reg(priv, status, 0);
+
+       /* Clear and invalidate message objects */
+       for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) {
+               cc770_write_reg(priv, msgobj[mo].ctrl0,
+                               INTPND_UNC | RXIE_RES |
+                               TXIE_RES | MSGVAL_RES);
+               cc770_write_reg(priv, msgobj[mo].ctrl0,
+                               INTPND_RES | RXIE_RES |
+                               TXIE_RES | MSGVAL_RES);
+               cc770_write_reg(priv, msgobj[mo].ctrl1,
+                               NEWDAT_RES | MSGLST_RES |
+                               TXRQST_RES | RMTPND_RES);
+               for (data = 0; data < 8; data++)
+                       cc770_write_reg(priv, msgobj[mo].data[data], 0);
+               for (id = 0; id < 4; id++)
+                       cc770_write_reg(priv, msgobj[mo].id[id], 0);
+               cc770_write_reg(priv, msgobj[mo].config, 0);
+       }
+
+       /* Set all global ID masks to "don't care" */
+       cc770_write_reg(priv, global_mask_std[0], 0);
+       cc770_write_reg(priv, global_mask_std[1], 0);
+       cc770_write_reg(priv, global_mask_ext[0], 0);
+       cc770_write_reg(priv, global_mask_ext[1], 0);
+       cc770_write_reg(priv, global_mask_ext[2], 0);
+       cc770_write_reg(priv, global_mask_ext[3], 0);
+
+}
+
+static int cc770_probe_chip(struct net_device *dev)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+
+       /* Enable configuration, put chip in bus-off, disable ints */
+       cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI);
+       /* Configure cpu interface / CLKOUT disable */
+       cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
+
+       /*
+        * Check if hardware reset is still inactive or maybe there
+        * is no chip in this address space
+        */
+       if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) {
+               netdev_info(dev, "probing @0x%p failed (reset)\n",
+                           priv->reg_base);
+               return -ENODEV;
+       }
+
+       /* Write and read back test pattern (some arbitrary values) */
+       cc770_write_reg(priv, msgobj[1].data[1], 0x25);
+       cc770_write_reg(priv, msgobj[2].data[3], 0x52);
+       cc770_write_reg(priv, msgobj[10].data[6], 0xc3);
+       if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) ||
+           (cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) ||
+           (cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) {
+               netdev_info(dev, "probing @0x%p failed (pattern)\n",
+                           priv->reg_base);
+               return -ENODEV;
+       }
+
+       /* Check if this chip is a CC770 supporting additional functions */
+       if (cc770_read_reg(priv, control) & CTRL_EAF)
+               priv->control_normal_mode |= CTRL_EAF;
+
+       return 0;
+}
+
+static void cc770_start(struct net_device *dev)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+
+       /* leave reset mode */
+       if (priv->can.state != CAN_STATE_STOPPED)
+               set_reset_mode(dev);
+
+       /* leave reset mode */
+       set_normal_mode(dev);
+}
+
+static int cc770_set_mode(struct net_device *dev, enum can_mode mode)
+{
+       switch (mode) {
+       case CAN_MODE_START:
+               cc770_start(dev);
+               netif_wake_queue(dev);
+               break;
+
+       default:
+               return -EOPNOTSUPP;
+       }
+
+       return 0;
+}
+
+static int cc770_set_bittiming(struct net_device *dev)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       struct can_bittiming *bt = &priv->can.bittiming;
+       u8 btr0, btr1;
+
+       btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
+       btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
+               (((bt->phase_seg2 - 1) & 0x7) << 4);
+       if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
+               btr1 |= 0x80;
+
+       netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
+
+       cc770_write_reg(priv, bit_timing_0, btr0);
+       cc770_write_reg(priv, bit_timing_1, btr1);
+
+       return 0;
+}
+
+static int cc770_get_berr_counter(const struct net_device *dev,
+                                 struct can_berr_counter *bec)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+
+       bec->txerr = cc770_read_reg(priv, tx_error_counter);
+       bec->rxerr = cc770_read_reg(priv, rx_error_counter);
+
+       return 0;
+}
+
+static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       struct net_device_stats *stats = &dev->stats;
+       struct can_frame *cf = (struct can_frame *)skb->data;
+       unsigned int mo = obj2msgobj(CC770_OBJ_TX);
+       u8 dlc, rtr;
+       u32 id;
+       int i;
+
+       if (can_dropped_invalid_skb(dev, skb))
+               return NETDEV_TX_OK;
+
+       if ((cc770_read_reg(priv,
+                           msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
+               netdev_err(dev, "TX register is still occupied!\n");
+               return NETDEV_TX_BUSY;
+       }
+
+       netif_stop_queue(dev);
+
+       dlc = cf->can_dlc;
+       id = cf->can_id;
+       if (cf->can_id & CAN_RTR_FLAG)
+               rtr = 0;
+       else
+               rtr = MSGCFG_DIR;
+       cc770_write_reg(priv, msgobj[mo].ctrl1,
+                       RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
+       cc770_write_reg(priv, msgobj[mo].ctrl0,
+                       MSGVAL_SET | TXIE_SET | RXIE_RES | INTPND_RES);
+       if (id & CAN_EFF_FLAG) {
+               id &= CAN_EFF_MASK;
+               cc770_write_reg(priv, msgobj[mo].config,
+                               (dlc << 4) | rtr | MSGCFG_XTD);
+               cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
+               cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
+               cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
+               cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
+       } else {
+               id &= CAN_SFF_MASK;
+               cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
+               cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
+               cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
+       }
+
+       for (i = 0; i < dlc; i++)
+               cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
+
+       /* Store echo skb before starting the transfer */
+       can_put_echo_skb(skb, dev, 0);
+
+       cc770_write_reg(priv, msgobj[mo].ctrl1,
+                       RMTPND_RES | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
+
+       stats->tx_bytes += dlc;
+
+
+       /*
+        * HM: We had some cases of repeated IRQs so make sure the
+        * INT is acknowledged I know it's already further up, but
+        * doing again fixed the issue
+        */
+       cc770_write_reg(priv, msgobj[mo].ctrl0,
+                       MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
+
+       return NETDEV_TX_OK;
+}
+
+static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       struct net_device_stats *stats = &dev->stats;
+       struct can_frame *cf;
+       struct sk_buff *skb;
+       u8 config;
+       u32 id;
+       int i;
+
+       skb = alloc_can_skb(dev, &cf);
+       if (!skb)
+               return;
+
+       config = cc770_read_reg(priv, msgobj[mo].config);
+
+       if (ctrl1 & RMTPND_SET) {
+               /*
+                * Unfortunately, the chip does not store the real message
+                * identifier of the received remote transmission request
+                * frame. Therefore we set it to 0.
+                */
+               cf->can_id = CAN_RTR_FLAG;
+               if (config & MSGCFG_XTD)
+                       cf->can_id |= CAN_EFF_FLAG;
+               cf->can_dlc = 0;
+       } else {
+               if (config & MSGCFG_XTD) {
+                       id = cc770_read_reg(priv, msgobj[mo].id[3]);
+                       id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
+                       id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
+                       id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
+                       id >>= 3;
+                       id |= CAN_EFF_FLAG;
+               } else {
+                       id = cc770_read_reg(priv, msgobj[mo].id[1]);
+                       id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
+                       id >>= 5;
+               }
+
+               cf->can_id = id;
+               cf->can_dlc = get_can_dlc((config & 0xf0) >> 4);
+               for (i = 0; i < cf->can_dlc; i++)
+                       cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
+       }
+       netif_rx(skb);
+
+       stats->rx_packets++;
+       stats->rx_bytes += cf->can_dlc;
+}
+
+static int cc770_err(struct net_device *dev, u8 status)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       struct net_device_stats *stats = &dev->stats;
+       struct can_frame *cf;
+       struct sk_buff *skb;
+       u8 lec;
+
+       netdev_dbg(dev, "status interrupt (%#x)\n", status);
+
+       skb = alloc_can_err_skb(dev, &cf);
+       if (!skb)
+               return -ENOMEM;
+
+       /* Use extended functions of the CC770 */
+       if (priv->control_normal_mode & CTRL_EAF) {
+               cf->data[6] = cc770_read_reg(priv, tx_error_counter);
+               cf->data[7] = cc770_read_reg(priv, rx_error_counter);
+       }
+
+       if (status & STAT_BOFF) {
+               /* Disable interrupts */
+               cc770_write_reg(priv, control, CTRL_INI);
+               cf->can_id |= CAN_ERR_BUSOFF;
+               priv->can.state = CAN_STATE_BUS_OFF;
+               priv->can.can_stats.bus_off++;
+               can_bus_off(dev);
+       } else if (status & STAT_WARN) {
+               cf->can_id |= CAN_ERR_CRTL;
+               /* Only the CC770 does show error passive */
+               if (cf->data[7] > 127) {
+                       cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE |
+                               CAN_ERR_CRTL_TX_PASSIVE;
+                       priv->can.state = CAN_STATE_ERROR_PASSIVE;
+                       priv->can.can_stats.error_passive++;
+               } else {
+                       cf->data[1] = CAN_ERR_CRTL_RX_WARNING |
+                               CAN_ERR_CRTL_TX_WARNING;
+                       priv->can.state = CAN_STATE_ERROR_WARNING;
+                       priv->can.can_stats.error_warning++;
+               }
+       } else {
+               /* Back to error avtive */
+               cf->can_id |= CAN_ERR_PROT;
+               cf->data[2] = CAN_ERR_PROT_ACTIVE;
+               priv->can.state = CAN_STATE_ERROR_ACTIVE;
+       }
+
+       lec = status & STAT_LEC_MASK;
+       if (lec < 7 && lec > 0) {
+               if (lec == STAT_LEC_ACK) {
+                       cf->can_id |= CAN_ERR_ACK;
+               } else {
+                       cf->can_id |= CAN_ERR_PROT;
+                       switch (lec) {
+                       case STAT_LEC_STUFF:
+                               cf->data[2] |= CAN_ERR_PROT_STUFF;
+                               break;
+                       case STAT_LEC_FORM:
+                               cf->data[2] |= CAN_ERR_PROT_FORM;
+                               break;
+                       case STAT_LEC_BIT1:
+                               cf->data[2] |= CAN_ERR_PROT_BIT1;
+                               break;
+                       case STAT_LEC_BIT0:
+                               cf->data[2] |= CAN_ERR_PROT_BIT0;
+                               break;
+                       case STAT_LEC_CRC:
+                               cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+                               break;
+                       }
+               }
+       }
+
+       netif_rx(skb);
+
+       stats->rx_packets++;
+       stats->rx_bytes += cf->can_dlc;
+
+       return 0;
+}
+
+static int cc770_status_interrupt(struct net_device *dev)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       u8 status;
+
+       status = cc770_read_reg(priv, status);
+       /* Reset the status register including RXOK and TXOK */
+       cc770_write_reg(priv, status, STAT_LEC_MASK);
+
+       if (status & (STAT_WARN | STAT_BOFF) ||
+           (status & STAT_LEC_MASK) != STAT_LEC_MASK) {
+               cc770_err(dev, status);
+               return status & STAT_BOFF;
+       }
+
+       return 0;
+}
+
+static void cc770_rx_interrupt(struct net_device *dev, unsigned int o)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       struct net_device_stats *stats = &dev->stats;
+       unsigned int mo = obj2msgobj(o);
+       u8 ctrl1;
+       int n = CC770_MAX_MSG;
+
+       while (n--) {
+               ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
+
+               if (!(ctrl1 & NEWDAT_SET))  {
+                       /* Check for RTR if additional functions are enabled */
+                       if (priv->control_normal_mode & CTRL_EAF) {
+                               if (!(cc770_read_reg(priv, msgobj[mo].ctrl0) &
+                                     INTPND_SET))
+                                       break;
+                       } else {
+                               break;
+                       }
+               }
+
+               if (ctrl1 & MSGLST_SET) {
+                       stats->rx_over_errors++;
+                       stats->rx_errors++;
+               }
+               if (mo < MSGOBJ_LAST)
+                       cc770_write_reg(priv, msgobj[mo].ctrl1,
+                                       NEWDAT_RES | MSGLST_RES |
+                                       TXRQST_UNC | RMTPND_UNC);
+               cc770_rx(dev, mo, ctrl1);
+
+               cc770_write_reg(priv, msgobj[mo].ctrl0,
+                               MSGVAL_SET | TXIE_RES |
+                               RXIE_SET | INTPND_RES);
+               cc770_write_reg(priv, msgobj[mo].ctrl1,
+                               NEWDAT_RES | MSGLST_RES |
+                               TXRQST_RES | RMTPND_RES);
+       }
+}
+
+static void cc770_rtr_interrupt(struct net_device *dev, unsigned int o)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       unsigned int mo = obj2msgobj(o);
+       u8 ctrl0, ctrl1;
+       int n = CC770_MAX_MSG;
+
+       while (n--) {
+               ctrl0 = cc770_read_reg(priv, msgobj[mo].ctrl0);
+               if (!(ctrl0 & INTPND_SET))
+                       break;
+
+               ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
+               cc770_rx(dev, mo, ctrl1);
+
+               cc770_write_reg(priv, msgobj[mo].ctrl0,
+                               MSGVAL_SET | TXIE_RES |
+                               RXIE_SET | INTPND_RES);
+               cc770_write_reg(priv, msgobj[mo].ctrl1,
+                               NEWDAT_RES | CPUUPD_SET |
+                               TXRQST_RES | RMTPND_RES);
+       }
+}
+
+static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       struct net_device_stats *stats = &dev->stats;
+       unsigned int mo = obj2msgobj(o);
+
+       /* Nothing more to send, switch off interrupts */
+       cc770_write_reg(priv, msgobj[mo].ctrl0,
+                       MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
+       /*
+        * We had some cases of repeated IRQ so make sure the
+        * INT is acknowledged
+        */
+       cc770_write_reg(priv, msgobj[mo].ctrl0,
+                       MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
+
+       stats->tx_packets++;
+       can_get_echo_skb(dev, 0);
+       netif_wake_queue(dev);
+}
+
+static irqreturn_t cc770_interrupt(int irq, void *dev_id)
+{
+       struct net_device *dev = (struct net_device *)dev_id;
+       struct cc770_priv *priv = netdev_priv(dev);
+       u8 intid;
+       int o, n = 0;
+
+       /* Shared interrupts and IRQ off? */
+       if (priv->can.state == CAN_STATE_STOPPED)
+               return IRQ_NONE;
+
+       if (priv->pre_irq)
+               priv->pre_irq(priv);
+
+       while (n < CC770_MAX_IRQ) {
+               /* Read the highest pending interrupt request */
+               intid = cc770_read_reg(priv, interrupt);
+               if (!intid)
+                       break;
+               n++;
+
+               if (intid == 1) {
+                       /* Exit in case of bus-off */
+                       if (cc770_status_interrupt(dev))
+                               break;
+               } else {
+                       o = intid2obj(intid);
+
+                       if (o >= CC770_OBJ_MAX) {
+                               netdev_err(dev, "Unexpected interrupt id %d\n",
+                                          intid);
+                               continue;
+                       }
+
+                       if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR)
+                               cc770_rtr_interrupt(dev, o);
+                       else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX)
+                               cc770_rx_interrupt(dev, o);
+                       else
+                               cc770_tx_interrupt(dev, o);
+               }
+       }
+
+       if (priv->post_irq)
+               priv->post_irq(priv);
+
+       if (n >= CC770_MAX_IRQ)
+               netdev_dbg(dev, "%d messages handled in ISR", n);
+
+       return (n) ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int cc770_open(struct net_device *dev)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       int err;
+
+       /* set chip into reset mode */
+       set_reset_mode(dev);
+
+       /* common open */
+       err = open_candev(dev);
+       if (err)
+               return err;
+
+       err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags,
+                         dev->name, dev);
+       if (err) {
+               close_candev(dev);
+               return -EAGAIN;
+       }
+
+       /* init and start chip */
+       cc770_start(dev);
+
+       netif_start_queue(dev);
+
+       return 0;
+}
+
+static int cc770_close(struct net_device *dev)
+{
+       netif_stop_queue(dev);
+       set_reset_mode(dev);
+
+       free_irq(dev->irq, dev);
+       close_candev(dev);
+
+       return 0;
+}
+
+struct net_device *alloc_cc770dev(int sizeof_priv)
+{
+       struct net_device *dev;
+       struct cc770_priv *priv;
+
+       dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv,
+                          CC770_ECHO_SKB_MAX);
+       if (!dev)
+               return NULL;
+
+       priv = netdev_priv(dev);
+
+       priv->dev = dev;
+       priv->can.bittiming_const = &cc770_bittiming_const;
+       priv->can.do_set_bittiming = cc770_set_bittiming;
+       priv->can.do_set_mode = cc770_set_mode;
+       priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
+
+       memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));
+
+       if (sizeof_priv)
+               priv->priv = (void *)priv + sizeof(struct cc770_priv);
+
+       return dev;
+}
+EXPORT_SYMBOL_GPL(alloc_cc770dev);
+
+void free_cc770dev(struct net_device *dev)
+{
+       free_candev(dev);
+}
+EXPORT_SYMBOL_GPL(free_cc770dev);
+
+static const struct net_device_ops cc770_netdev_ops = {
+       .ndo_open = cc770_open,
+       .ndo_stop = cc770_close,
+       .ndo_start_xmit = cc770_start_xmit,
+       .ndo_change_mtu = can_change_mtu,
+};
+
+int register_cc770dev(struct net_device *dev)
+{
+       struct cc770_priv *priv = netdev_priv(dev);
+       int err;
+
+       err = cc770_probe_chip(dev);
+       if (err)
+               return err;
+
+       dev->netdev_ops = &cc770_netdev_ops;
+
+       dev->flags |= IFF_ECHO; /* we support local echo */
+
+       /* Should we use additional functions? */
+       if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
+               priv->can.do_get_berr_counter = cc770_get_berr_counter;
+               priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
+               netdev_dbg(dev, "i82527 mode with additional functions\n");
+       } else {
+               priv->control_normal_mode = CTRL_IE | CTRL_EIE;
+               netdev_dbg(dev, "strict i82527 compatibility mode\n");
+       }
+
+       chipset_init(priv);
+       set_reset_mode(dev);
+
+       return register_candev(dev);
+}
+EXPORT_SYMBOL_GPL(register_cc770dev);
+
+void unregister_cc770dev(struct net_device *dev)
+{
+       set_reset_mode(dev);
+       unregister_candev(dev);
+}
+EXPORT_SYMBOL_GPL(unregister_cc770dev);
+
+static __init int cc770_init(void)
+{
+       if (msgobj15_eff) {
+               cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
+               cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
+       }
+
+       pr_info("CAN netdevice driver\n");
+
+       return 0;
+}
+module_init(cc770_init);
+
+static __exit void cc770_exit(void)
+{
+       pr_info("driver removed\n");
+}
+module_exit(cc770_exit);