can: SJA1000 driver for EMS PCI cards

The patch adds support for the one or two channel CPC-PCI and CPC-PCIe
cards from EMS Dr. Thomas Wuensche (http://www.ems-wuensche.de).

Signed-off-by: Sebastian Haas <haas@ems-wuensche.com>
Signed-off-by: Markus Plessing <plessing@ems-wuensche.com>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 329 insertions, 0 deletions

diff --git a/drivers/net/can/sja1000/ems_pci.c b/drivers/net/can/sja1000/ems_pci.c
new file mode 100644
index 00000000000..3cd2ff9165e
--- /dev/null
+++ b/drivers/net/can/sja1000/ems_pci.c
@@ -0,0 +1,329 @@
+/*
+ * 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  "ems_pci"
+
+MODULE_AUTHOR("Sebastian Haas <haas@ems-wuenche.com>");
+MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-PCI/PCIe CAN cards");
+MODULE_SUPPORTED_DEVICE("EMS CPC-PCI/PCIe CAN card");
+MODULE_LICENSE("GPL v2");
+
+#define EMS_PCI_MAX_CHAN 2
+
+struct ems_pci_card {
+	int channels;
+
+	struct pci_dev *pci_dev;
+	struct net_device *net_dev[EMS_PCI_MAX_CHAN];
+
+	void __iomem *conf_addr;
+	void __iomem *base_addr;
+};
+
+#define EMS_PCI_CAN_CLOCK (16000000 / 2)
+
+/*
+ * Register definitions and descriptions are from LinCAN 0.3.3.
+ *
+ * PSB4610 PITA-2 bridge control registers
+ */
+#define PITA2_ICR           0x00	/* Interrupt Control Register */
+#define PITA2_ICR_INT0      0x00000002	/* [RC] INT0 Active/Clear */
+#define PITA2_ICR_INT0_EN   0x00020000	/* [RW] Enable INT0 */
+
+#define PITA2_MISC          0x1c	/* Miscellaneous Register */
+#define PITA2_MISC_CONFIG   0x04000000	/* Multiplexed parallel interface */
+
+/*
+ * 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 EMS_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 EMS_PCI_CDR             (CDR_CBP | CDR_CLKOUT_MASK)
+#define EMS_PCI_MEM_SIZE        4096  /* Size of the remapped io-memory */
+#define EMS_PCI_CAN_BASE_OFFSET 0x400 /* offset where the controllers starts */
+#define EMS_PCI_CAN_CTRL_SIZE   0x200 /* memory size for each controller */
+
+#define EMS_PCI_PORT_BYTES  0x4     /* Each register occupies 4 bytes */
+
+#define EMS_PCI_VENDOR_ID   0x110a  /* PCI device and vendor ID */
+#define EMS_PCI_DEVICE_ID   0x2104
+
+static struct pci_device_id ems_pci_tbl[] = {
+	{EMS_PCI_VENDOR_ID, EMS_PCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
+	{0,}
+};
+MODULE_DEVICE_TABLE(pci, ems_pci_tbl);
+
+/*
+ * Helper to read internal registers from card logic (not CAN)
+ */
+static u8 ems_pci_readb(struct ems_pci_card *card, unsigned int port)
+{
+	return readb((void __iomem *)card->base_addr
+			+ (port * EMS_PCI_PORT_BYTES));
+}
+
+static u8 ems_pci_read_reg(const struct net_device *dev, int port)
+{
+	return readb((void __iomem *)dev->base_addr
+			+ (port * EMS_PCI_PORT_BYTES));
+}
+
+static void ems_pci_write_reg(const struct net_device *dev, int port, u8 val)
+{
+	writeb(val, (void __iomem *)dev->base_addr
+		+ (port * EMS_PCI_PORT_BYTES));
+}
+
+static void ems_pci_post_irq(const struct net_device *dev)
+{
+	struct sja1000_priv *priv = netdev_priv(dev);
+	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;
+
+	/* reset int flag of pita */
+	writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0, card->conf_addr
+		+ PITA2_ICR);
+}
+
+/*
+ * Check if a CAN controller is present at the specified location
+ * by trying to set 'em into the PeliCAN mode
+ */
+static inline int ems_pci_check_chan(struct net_device *dev)
+{
+	unsigned char res;
+
+	/* Make sure SJA1000 is in reset mode */
+	ems_pci_write_reg(dev, REG_MOD, 1);
+
+	ems_pci_write_reg(dev, REG_CDR, CDR_PELICAN);
+
+	/* read reset-values */
+	res = ems_pci_read_reg(dev, REG_CDR);
+
+	if (res == CDR_PELICAN)
+		return 1;
+
+	return 0;
+}
+
+static void ems_pci_del_card(struct pci_dev *pdev)
+{
+	struct ems_pci_card *card = pci_get_drvdata(pdev);
+	struct net_device *dev;
+	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);
+		free_sja1000dev(dev);
+	}
+
+	if (card->base_addr != NULL)
+		pci_iounmap(card->pci_dev, card->base_addr);
+
+	if (card->conf_addr != NULL)
+		pci_iounmap(card->pci_dev, card->conf_addr);
+
+	kfree(card);
+
+	pci_disable_device(pdev);
+	pci_set_drvdata(pdev, NULL);
+}
+
+static void ems_pci_card_reset(struct ems_pci_card *card)
+{
+	/* Request board reset */
+	writeb(0, card->base_addr);
+}
+
+/*
+ * Probe PCI device for EMS CAN signature and register each available
+ * CAN channel to SJA1000 Socket-CAN subsystem.
+ */
+static int __devinit ems_pci_add_card(struct pci_dev *pdev,
+					const struct pci_device_id *ent)
+{
+	struct sja1000_priv *priv;
+	struct net_device *dev;
+	struct ems_pci_card *card;
+	int err, i;
+
+	/* Enabling PCI device */
+	if (pci_enable_device(pdev) < 0) {
+		dev_err(&pdev->dev, "Enabling PCI device failed\n");
+		return -ENODEV;
+	}
+
+	/* Allocating card structures to hold addresses, ... */
+	card = kzalloc(sizeof(struct ems_pci_card), GFP_KERNEL);
+	if (card == NULL) {
+		dev_err(&pdev->dev, "Unable to allocate memory\n");
+		pci_disable_device(pdev);
+		return -ENOMEM;
+	}
+
+	pci_set_drvdata(pdev, card);
+
+	card->pci_dev = pdev;
+
+	card->channels = 0;
+
+	/* Remap PITA configuration space, and controller memory area */
+	card->conf_addr = pci_iomap(pdev, 0, EMS_PCI_MEM_SIZE);
+	if (card->conf_addr == NULL) {
+		err = -ENOMEM;
+
+		goto failure_cleanup;
+	}
+
+	card->base_addr = pci_iomap(pdev, 1, EMS_PCI_MEM_SIZE);
+	if (card->base_addr == NULL) {
+		err = -ENOMEM;
+
+		goto failure_cleanup;
+	}
+
+	/* Configure PITA-2 parallel interface (enable MUX) */
+	writel(PITA2_MISC_CONFIG, card->conf_addr + PITA2_MISC);
+
+	/* Check for unique EMS CAN signature */
+	if (ems_pci_readb(card, 0) != 0x55 ||
+	    ems_pci_readb(card, 1) != 0xAA ||
+	    ems_pci_readb(card, 2) != 0x01 ||
+	    ems_pci_readb(card, 3) != 0xCB ||
+	    ems_pci_readb(card, 4) != 0x11) {
+		dev_err(&pdev->dev, "Not EMS Dr. Thomas Wuensche interface\n");
+
+		err = -ENODEV;
+		goto failure_cleanup;
+	}
+
+	ems_pci_card_reset(card);
+
+	/* Detect available channels */
+	for (i = 0; i < EMS_PCI_MAX_CHAN; i++) {
+		dev = alloc_sja1000dev(0);
+		if (dev == NULL) {
+			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;
+		dev->base_addr = (unsigned long)(card->base_addr
+						+ EMS_PCI_CAN_BASE_OFFSET
+						+ (i * EMS_PCI_CAN_CTRL_SIZE));
+
+		/* Check if channel is present */
+		if (ems_pci_check_chan(dev)) {
+			priv->read_reg  = ems_pci_read_reg;
+			priv->write_reg = ems_pci_write_reg;
+			priv->post_irq  = ems_pci_post_irq;
+			priv->can.clock.freq = EMS_PCI_CAN_CLOCK;
+			priv->ocr = EMS_PCI_OCR;
+			priv->cdr = EMS_PCI_CDR;
+
+			SET_NETDEV_DEV(dev, &pdev->dev);
+
+			/* Enable interrupts from card */
+			writel(PITA2_ICR_INT0_EN, card->conf_addr + PITA2_ICR);
+
+			/* 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 %#lX, irq %d\n",
+						i + 1, dev->base_addr,
+						dev->irq);
+		} else {
+			free_sja1000dev(dev);
+		}
+	}
+
+	return 0;
+
+failure_cleanup:
+	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);
+
+	ems_pci_del_card(pdev);
+
+	return err;
+}
+
+static struct pci_driver ems_pci_driver = {
+	.name = DRV_NAME,
+	.id_table = ems_pci_tbl,
+	.probe = ems_pci_add_card,
+	.remove = ems_pci_del_card,
+};
+
+static int __init ems_pci_init(void)
+{
+	return pci_register_driver(&ems_pci_driver);
+}
+
+static void __exit ems_pci_exit(void)
+{
+	pci_unregister_driver(&ems_pci_driver);
+}
+
+module_init(ems_pci_init);
+module_exit(ems_pci_exit);
+