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>

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

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

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);