can: add support for CAN interface cards based on the PLX90xx PCI bridge

This driver is for CAN interface cards based on the PLX90xx PCI bridge.
Driver supports now:
 - Adlink PCI-7841/cPCI-7841 card (http://www.adlinktech.com/)
 - Adlink PCI-7841/cPCI-7841 SE card
 - Marathon CAN-bus-PCI card (http://www.marathon.ru/)
 - TEWS TECHNOLOGIES TPMC810 card (http://www.tews.com/)

Changes since v1:
 - Added some defines for static inline int plx_pci_check_sja1000(...)
 - static struct pci_device_id plx_pci_tbl[] replaced by
   static DEFINE_PCI_DEVICE_TABLE(plx_pci_tbl)
 - Typo fixed

Signed-off-by: Pavel Cheblakov <P.B.Cheblakov@inp.nsk.su>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 485 insertions, 0 deletions

diff --git a/drivers/net/can/sja1000/Kconfig b/drivers/net/can/sja1000/Kconfig
index 4c674927f247..9e277d64a318 100644
--- a/drivers/net/can/sja1000/Kconfig
+++ b/drivers/net/can/sja1000/Kconfig
@@ -44,4 +44,16 @@ config CAN_KVASER_PCI
           This driver is for the the PCIcanx and PCIcan cards (1, 2 or
           4 channel) from Kvaser (http://www.kvaser.com).
 
+config CAN_PLX_PCI
+        tristate "PLX90xx PCI-bridge based Cards"
+        depends on PCI
+        ---help---
+          This driver is for CAN interface cards based on
+          the PLX90xx PCI bridge.
+          Driver supports now:
+           - Adlink PCI-7841/cPCI-7841 card (http://www.adlinktech.com/)
+           - Adlink PCI-7841/cPCI-7841 SE card
+           - Marathon CAN-bus-PCI card (http://www.marathon.ru/)
+           - TEWS TECHNOLOGIES TPMC810 card (http://www.tews.com/)
+
 endif
diff --git a/drivers/net/can/sja1000/Makefile b/drivers/net/can/sja1000/Makefile
index 9d245ac03965..ce924553995d 100644
--- a/drivers/net/can/sja1000/Makefile
+++ b/drivers/net/can/sja1000/Makefile
@@ -8,5 +8,6 @@ obj-$(CONFIG_CAN_SJA1000_PLATFORM) += sja1000_platform.o
 obj-$(CONFIG_CAN_SJA1000_OF_PLATFORM) += sja1000_of_platform.o
 obj-$(CONFIG_CAN_EMS_PCI) += ems_pci.o
 obj-$(CONFIG_CAN_KVASER_PCI) += kvaser_pci.o
+obj-$(CONFIG_CAN_PLX_PCI) += plx_pci.o
 
 ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/sja1000/plx_pci.c b/drivers/net/can/sja1000/plx_pci.c
new file mode 100644
index 000000000000..6b46a6395f80
--- /dev/null
+++ b/drivers/net/can/sja1000/plx_pci.c
@@ -0,0 +1,472 @@
+/*
+ * Copyright (C) 2008-2010 Pavel Cheblakov <P.B.Cheblakov@inp.nsk.su>
+ *
+ * Derived from the ems_pci.c driver:
+ *      Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
+ *      Copyright (C) 2008 Markus Plessing <plessing@ems-wuensche.com>
+ *      Copyright (C) 2008 Sebastian Haas <haas@ems-wuensche.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.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/netdevice.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/io.h>
+
+#include "sja1000.h"
+
+#define DRV_NAME  "sja1000_plx_pci"
+
+MODULE_AUTHOR("Pavel Cheblakov <P.B.Cheblakov@inp.nsk.su>");
+MODULE_DESCRIPTION("Socket-CAN driver for PLX90xx PCI-bridge cards with "
+                   "the SJA1000 chips");
+MODULE_SUPPORTED_DEVICE("Adlink PCI-7841/cPCI-7841, "
+                        "Adlink PCI-7841/cPCI-7841 SE, "
+                        "Marathon CAN-bus-PCI, "
+                        "TEWS TECHNOLOGIES TPMC810");
+MODULE_LICENSE("GPL v2");
+
+#define PLX_PCI_MAX_CHAN 2
+
+struct plx_pci_card {
+        int channels;                   /* detected channels count */
+        struct net_device *net_dev[PLX_PCI_MAX_CHAN];
+        void __iomem *conf_addr;
+};
+
+#define PLX_PCI_CAN_CLOCK (16000000 / 2)
+
+/* PLX90xx registers */
+#define PLX_INTCSR      0x4c            /* Interrupt Control/Status */
+#define PLX_CNTRL       0x50            /* User I/O, Direct Slave Response,
+                                         * Serial EEPROM, and Initialization
+                                         * Control register
+                                         */
+
+#define PLX_LINT1_EN    0x1             /* Local interrupt 1 enable */
+#define PLX_LINT2_EN    (1 << 3)        /* Local interrupt 2 enable */
+#define PLX_PCI_INT_EN  (1 << 6)        /* PCI Interrupt Enable */
+#define PLX_PCI_RESET   (1 << 30)       /* PCI Adapter Software Reset */
+
+/*
+ * The board configuration is probably following:
+ * RX1 is connected to ground.
+ * TX1 is not connected.
+ * CLKO is not connected.
+ * Setting the OCR register to 0xDA is a good idea.
+ * This means normal output mode, push-pull and the correct polarity.
+ */
+#define PLX_PCI_OCR     (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
+
+/*
+ * In the CDR register, you should set CBP to 1.
+ * You will probably also want to set the clock divider value to 7
+ * (meaning direct oscillator output) because the second SJA1000 chip
+ * is driven by the first one CLKOUT output.
+ */
+#define PLX_PCI_CDR                     (CDR_CBP | CDR_CLKOUT_MASK)
+
+/* SJA1000 Control Register in the BasicCAN Mode */
+#define REG_CR                          0x00
+
+/* States of some SJA1000 registers after hardware reset in the BasicCAN mode*/
+#define REG_CR_BASICCAN_INITIAL         0x21
+#define REG_CR_BASICCAN_INITIAL_MASK    0xa1
+#define REG_SR_BASICCAN_INITIAL         0x0c
+#define REG_IR_BASICCAN_INITIAL         0xe0
+
+/* States of some SJA1000 registers after hardware reset in the PeliCAN mode*/
+#define REG_MOD_PELICAN_INITIAL         0x01
+#define REG_SR_PELICAN_INITIAL          0x3c
+#define REG_IR_PELICAN_INITIAL          0x00
+
+#define ADLINK_PCI_VENDOR_ID            0x144A
+#define ADLINK_PCI_DEVICE_ID            0x7841
+
+#define MARATHON_PCI_DEVICE_ID          0x2715
+
+#define TEWS_PCI_VENDOR_ID              0x1498
+#define TEWS_PCI_DEVICE_ID_TMPC810      0x032A
+
+static void plx_pci_reset_common(struct pci_dev *pdev);
+static void plx_pci_reset_marathon(struct pci_dev *pdev);
+
+struct plx_pci_channel_map {
+        u32 bar;
+        u32 offset;
+        u32 size;               /* 0x00 - auto, e.g. length of entire bar */
+};
+
+struct plx_pci_card_info {
+        const char *name;
+        int channel_count;
+        u32 can_clock;
+        u8 ocr;                 /* output control register */
+        u8 cdr;                 /* clock divider register */
+
+        /* Parameters for mapping local configuration space */
+        struct plx_pci_channel_map conf_map;
+
+        /* Parameters for mapping the SJA1000 chips */
+        struct plx_pci_channel_map chan_map_tbl[PLX_PCI_MAX_CHAN];
+
+        /* Pointer to device-dependent reset function */
+        void (*reset_func)(struct pci_dev *pdev);
+};
+
+static struct plx_pci_card_info plx_pci_card_info_adlink __devinitdata = {
+        "Adlink PCI-7841/cPCI-7841", 2,
+        PLX_PCI_CAN_CLOCK, PLX_PCI_OCR, PLX_PCI_CDR,
+        {1, 0x00, 0x00}, { {2, 0x00, 0x80}, {2, 0x80, 0x80} },
+        &plx_pci_reset_common
+        /* based on PLX9052 */
+};
+
+static struct plx_pci_card_info plx_pci_card_info_adlink_se __devinitdata = {
+        "Adlink PCI-7841/cPCI-7841 SE", 2,
+        PLX_PCI_CAN_CLOCK, PLX_PCI_OCR, PLX_PCI_CDR,
+        {0, 0x00, 0x00}, { {2, 0x00, 0x80}, {2, 0x80, 0x80} },
+        &plx_pci_reset_common
+        /* based on PLX9052 */
+};
+
+static struct plx_pci_card_info plx_pci_card_info_marathon __devinitdata = {
+        "Marathon CAN-bus-PCI", 2,
+        PLX_PCI_CAN_CLOCK, PLX_PCI_OCR, PLX_PCI_CDR,
+        {0, 0x00, 0x00}, { {2, 0x00, 0x00}, {4, 0x00, 0x00} },
+        &plx_pci_reset_marathon
+        /* based on PLX9052 */
+};
+
+static struct plx_pci_card_info plx_pci_card_info_tews __devinitdata = {
+        "TEWS TECHNOLOGIES TPMC810", 2,
+        PLX_PCI_CAN_CLOCK, PLX_PCI_OCR, PLX_PCI_CDR,
+        {0, 0x00, 0x00}, { {2, 0x000, 0x80}, {2, 0x100, 0x80} },
+        &plx_pci_reset_common
+        /* based on PLX9030 */
+};
+
+static DEFINE_PCI_DEVICE_TABLE(plx_pci_tbl) = {
+        {
+                /* Adlink PCI-7841/cPCI-7841 */
+                ADLINK_PCI_VENDOR_ID, ADLINK_PCI_DEVICE_ID,
+                PCI_ANY_ID, PCI_ANY_ID,
+                PCI_CLASS_NETWORK_OTHER << 8, ~0,
+                (kernel_ulong_t)&plx_pci_card_info_adlink
+        },
+        {
+                /* Adlink PCI-7841/cPCI-7841 SE */
+                ADLINK_PCI_VENDOR_ID, ADLINK_PCI_DEVICE_ID,
+                PCI_ANY_ID, PCI_ANY_ID,
+                PCI_CLASS_COMMUNICATION_OTHER << 8, ~0,
+                (kernel_ulong_t)&plx_pci_card_info_adlink_se
+        },
+        {
+                /* Marathon CAN-bus-PCI card */
+                PCI_VENDOR_ID_PLX, MARATHON_PCI_DEVICE_ID,
+                PCI_ANY_ID, PCI_ANY_ID,
+                0, 0,
+                (kernel_ulong_t)&plx_pci_card_info_marathon
+        },
+        {
+                /* TEWS TECHNOLOGIES TPMC810 card */
+                TEWS_PCI_VENDOR_ID, TEWS_PCI_DEVICE_ID_TMPC810,
+                PCI_ANY_ID, PCI_ANY_ID,
+                0, 0,
+                (kernel_ulong_t)&plx_pci_card_info_tews
+        },
+        { 0,}
+};
+MODULE_DEVICE_TABLE(pci, plx_pci_tbl);
+
+static u8 plx_pci_read_reg(const struct sja1000_priv *priv, int port)
+{
+        return ioread8(priv->reg_base + port);
+}
+
+static void plx_pci_write_reg(const struct sja1000_priv *priv, int port, u8 val)
+{
+        iowrite8(val, priv->reg_base + port);
+}
+
+/*
+ * Check if a CAN controller is present at the specified location
+ * by trying to switch 'em from the Basic mode into the PeliCAN mode.
+ * Also check states of some registers in reset mode.
+ */
+static inline int plx_pci_check_sja1000(const struct sja1000_priv *priv)
+{
+        int flag = 0;
+
+        /*
+         * Check registers after hardware reset (the Basic mode)
+         * See states on p. 10 of the Datasheet.
+         */
+        if ((priv->read_reg(priv, REG_CR) & REG_CR_BASICCAN_INITIAL_MASK) ==
+            REG_CR_BASICCAN_INITIAL &&
+            (priv->read_reg(priv, REG_SR) == REG_SR_BASICCAN_INITIAL) &&
+            (priv->read_reg(priv, REG_IR) == REG_IR_BASICCAN_INITIAL))
+                flag = 1;
+
+        /* Bring the SJA1000 into the PeliCAN mode*/
+        priv->write_reg(priv, REG_CDR, CDR_PELICAN);
+
+        /*
+         * Check registers after reset in the PeliCAN mode.
+         * See states on p. 23 of the Datasheet.
+         */
+        if (priv->read_reg(priv, REG_MOD) == REG_MOD_PELICAN_INITIAL &&
+            priv->read_reg(priv, REG_SR) == REG_SR_PELICAN_INITIAL &&
+            priv->read_reg(priv, REG_IR) == REG_IR_PELICAN_INITIAL)
+                return flag;
+
+        return 0;
+}
+
+/*
+ * PLX90xx software reset
+ * Also LRESET# asserts and brings to reset device on the Local Bus (if wired).
+ * For most cards it's enough for reset the SJA1000 chips.
+ */
+static void plx_pci_reset_common(struct pci_dev *pdev)
+{
+        struct plx_pci_card *card = pci_get_drvdata(pdev);
+        u32 cntrl;
+
+        cntrl = ioread32(card->conf_addr + PLX_CNTRL);
+        cntrl |= PLX_PCI_RESET;
+        iowrite32(cntrl, card->conf_addr + PLX_CNTRL);
+        udelay(100);
+        cntrl ^= PLX_PCI_RESET;
+        iowrite32(cntrl, card->conf_addr + PLX_CNTRL);
+};
+
+/* Special reset function for Marathon card */
+static void plx_pci_reset_marathon(struct pci_dev *pdev)
+{
+        void __iomem *reset_addr;
+        int i;
+        int reset_bar[2] = {3, 5};
+
+        plx_pci_reset_common(pdev);
+
+        for (i = 0; i < 2; i++) {
+                reset_addr = pci_iomap(pdev, reset_bar[i], 0);
+                if (!reset_addr) {
+                        dev_err(&pdev->dev, "Failed to remap reset "
+                                "space %d (BAR%d)\n", i, reset_bar[i]);
+                } else {
+                        /* reset the SJA1000 chip */
+                        iowrite8(0x1, reset_addr);
+                        udelay(100);
+                        pci_iounmap(pdev, reset_addr);
+                }
+        }
+}
+
+static void plx_pci_del_card(struct pci_dev *pdev)
+{
+        struct plx_pci_card *card = pci_get_drvdata(pdev);
+        struct net_device *dev;
+        struct sja1000_priv *priv;
+        int i = 0;
+
+        for (i = 0; i < card->channels; i++) {
+                dev = card->net_dev[i];
+                if (!dev)
+                        continue;
+
+                dev_info(&pdev->dev, "Removing %s\n", dev->name);
+                unregister_sja1000dev(dev);
+                priv = netdev_priv(dev);
+                if (priv->reg_base)
+                        pci_iounmap(pdev, priv->reg_base);
+                free_sja1000dev(dev);
+        }
+
+        plx_pci_reset_common(pdev);
+
+        /*
+         * Disable interrupts from PCI-card (PLX90xx) and disable Local_1,
+         * Local_2 interrupts
+         */
+        iowrite32(0x0, card->conf_addr + PLX_INTCSR);
+
+        if (card->conf_addr)
+                pci_iounmap(pdev, card->conf_addr);
+
+        kfree(card);
+
+        pci_disable_device(pdev);
+        pci_set_drvdata(pdev, NULL);
+}
+
+/*
+ * Probe PLX90xx based device for the SJA1000 chips and register each
+ * available CAN channel to SJA1000 Socket-CAN subsystem.
+ */
+static int __devinit plx_pci_add_card(struct pci_dev *pdev,
+                                      const struct pci_device_id *ent)
+{
+        struct sja1000_priv *priv;
+        struct net_device *dev;
+        struct plx_pci_card *card;
+        struct plx_pci_card_info *ci;
+        int err, i;
+        u32 val;
+        void __iomem *addr;
+
+        ci = (struct plx_pci_card_info *)ent->driver_data;
+
+        if (pci_enable_device(pdev) < 0) {
+                dev_err(&pdev->dev, "Failed to enable PCI device\n");
+                return -ENODEV;
+        }
+
+        dev_info(&pdev->dev, "Detected \"%s\" card at slot #%i\n",
+                 ci->name, PCI_SLOT(pdev->devfn));
+
+        /* Allocate card structures to hold addresses, ... */
+        card = kzalloc(sizeof(*card), GFP_KERNEL);
+        if (!card) {
+                dev_err(&pdev->dev, "Unable to allocate memory\n");
+                pci_disable_device(pdev);
+                return -ENOMEM;
+        }
+
+        pci_set_drvdata(pdev, card);
+
+        card->channels = 0;
+
+        /* Remap PLX90xx configuration space */
+        addr = pci_iomap(pdev, ci->conf_map.bar, ci->conf_map.size);
+        if (!addr) {
+                err = -ENOMEM;
+                dev_err(&pdev->dev, "Failed to remap configuration space "
+                        "(BAR%d)\n", ci->conf_map.bar);
+                goto failure_cleanup;
+        }
+        card->conf_addr = addr + ci->conf_map.offset;
+
+        ci->reset_func(pdev);
+
+        /* Detect available channels */
+        for (i = 0; i < ci->channel_count; i++) {
+                struct plx_pci_channel_map *cm = &ci->chan_map_tbl[i];
+
+                dev = alloc_sja1000dev(0);
+                if (!dev) {
+                        err = -ENOMEM;
+                        goto failure_cleanup;
+                }
+
+                card->net_dev[i] = dev;
+                priv = netdev_priv(dev);
+                priv->priv = card;
+                priv->irq_flags = IRQF_SHARED;
+
+                dev->irq = pdev->irq;
+
+                /*
+                 * Remap IO space of the SJA1000 chips
+                 * This is device-dependent mapping
+                 */
+                addr = pci_iomap(pdev, cm->bar, cm->size);
+                if (!addr) {
+                        err = -ENOMEM;
+                        dev_err(&pdev->dev, "Failed to remap BAR%d\n", cm->bar);
+                        goto failure_cleanup;
+                }
+
+                priv->reg_base = addr + cm->offset;
+                priv->read_reg = plx_pci_read_reg;
+                priv->write_reg = plx_pci_write_reg;
+
+                /* Check if channel is present */
+                if (plx_pci_check_sja1000(priv)) {
+                        priv->can.clock.freq = ci->can_clock;
+                        priv->ocr = ci->ocr;
+                        priv->cdr = ci->cdr;
+
+                        SET_NETDEV_DEV(dev, &pdev->dev);
+
+                        /* Register SJA1000 device */
+                        err = register_sja1000dev(dev);
+                        if (err) {
+                                dev_err(&pdev->dev, "Registering device failed "
+                                        "(err=%d)\n", err);
+                                free_sja1000dev(dev);
+                                goto failure_cleanup;
+                        }
+
+                        card->channels++;
+
+                        dev_info(&pdev->dev, "Channel #%d at 0x%p, irq %d "
+                                 "registered as %s\n", i + 1, priv->reg_base,
+                                 dev->irq, dev->name);
+                } else {
+                        dev_err(&pdev->dev, "Channel #%d not detected\n",
+                                i + 1);
+                        free_sja1000dev(dev);
+                }
+        }
+
+        if (!card->channels) {
+                err = -ENODEV;
+                goto failure_cleanup;
+        }
+
+        /*
+         * Enable interrupts from PCI-card (PLX90xx) and enable Local_1,
+         * Local_2 interrupts from the SJA1000 chips
+         */
+        val = ioread32(card->conf_addr + PLX_INTCSR);
+        val |= PLX_LINT1_EN | PLX_LINT2_EN | PLX_PCI_INT_EN;
+        iowrite32(val, card->conf_addr + PLX_INTCSR);
+
+        return 0;
+
+failure_cleanup:
+        dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);
+
+        plx_pci_del_card(pdev);
+
+        return err;
+}
+
+static struct pci_driver plx_pci_driver = {
+        .name = DRV_NAME,
+        .id_table = plx_pci_tbl,
+        .probe = plx_pci_add_card,
+        .remove = plx_pci_del_card,
+};
+
+static int __init plx_pci_init(void)
+{
+        return pci_register_driver(&plx_pci_driver);
+}
+
+static void __exit plx_pci_exit(void)
+{
+        pci_unregister_driver(&plx_pci_driver);
+}
+
+module_init(plx_pci_init);
+module_exit(plx_pci_exit);