can: sja1000: legacy SJA1000 ISA bus driver

This patch adds support for legacy SJA1000 CAN controllers on the ISA
or PC-104 bus. The I/O port or memory address and the IRQ number must
be specified via module parameters:

  insmod sja1000_isa.ko port=0x310,0x380 irq=7,11

for ISA devices using I/O ports or:

  insmod sja1000_isa.ko mem=0xd1000,0xd1000 irq=7,11

for memory mapped ISA devices.

Indirect access via address and data port is supported as well:

  insmod sja1000_isa.ko port=0x310,0x380 indirect=1 irq=7,11

Here is a full list of the supported module parameters:

  port:I/O port number (array of ulong)
  mem:I/O memory address (array of ulong)
  indirect:Indirect access via address and data port (array of byte)
  irq:IRQ number (array of int)
  clk:External oscillator clock frequency (default=16000000 [16 MHz])
      (array of int)
  cdr:Clock divider register (default=0x48 [CDR_CBP | CDR_CLK_OFF])
      (array of byte)
  ocr:Output clock register (default=0x18 [OCR_TX0_PUSHPULL])
      (array of byte)

Note: for clk, cdr, ocr, the first argument re-defines the default
for all other devices, e.g.:

 insmod sja1000_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000

is equivalent to

 insmod sja1000_isa.ko mem=0xd1000,0xd1000 irq=7,11 \
                       clk=24000000,24000000

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Tested-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 289 insertions, 0 deletions

diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
index 30ae55d..0900743 100644
--- a/drivers/net/can/Kconfig
+++ b/drivers/net/can/Kconfig
@@ -41,6 +41,13 @@ config CAN_SJA1000
 	---help---
 	  Driver for the SJA1000 CAN controllers from Philips or NXP
 
+config CAN_SJA1000_ISA
+	depends on CAN_SJA1000 && ISA
+	tristate "ISA Bus based legacy SJA1000 driver"
+	---help---
+	  This driver adds legacy support for SJA1000 chips connected to
+	  the ISA bus using I/O port, memory mapped or indirect access.
+
 config CAN_SJA1000_PLATFORM
 	depends on CAN_SJA1000
 	tristate "Generic Platform Bus based SJA1000 driver"
diff --git a/drivers/net/can/sja1000/Makefile b/drivers/net/can/sja1000/Makefile
index 9d0c08d..9d245ac 100644
--- a/drivers/net/can/sja1000/Makefile
+++ b/drivers/net/can/sja1000/Makefile
@@ -3,6 +3,7 @@
 #
 
 obj-$(CONFIG_CAN_SJA1000) += sja1000.o
+obj-$(CONFIG_CAN_SJA1000_ISA) += sja1000_isa.o
 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
diff --git a/drivers/net/can/sja1000/sja1000_isa.c b/drivers/net/can/sja1000/sja1000_isa.c
new file mode 100644
index 0000000..a6a51f1
--- /dev/null
+++ b/drivers/net/can/sja1000/sja1000_isa.c
@@ -0,0 +1,281 @@
+/*
+ * Copyright (C) 2009 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.
+ *
+ * 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/isa.h>
+#include <linux/interrupt.h>
+#include <linux/netdevice.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/platform/sja1000.h>
+
+#include "sja1000.h"
+
+#define DRV_NAME "sja1000_isa"
+
+#define MAXDEV 8
+
+MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
+MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the ISA bus");
+MODULE_LICENSE("GPL v2");
+
+#define CLK_DEFAULT	16000000	/* 16 MHz */
+#define CDR_DEFAULT	(CDR_CBP | CDR_CLK_OFF)
+#define OCR_DEFAULT	OCR_TX0_PUSHPULL
+
+static unsigned long port[MAXDEV];
+static unsigned long mem[MAXDEV];
+static int __devinitdata irq[MAXDEV];
+static int __devinitdata clk[MAXDEV];
+static char __devinitdata cdr[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
+static char __devinitdata ocr[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
+static char __devinitdata indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1};
+
+module_param_array(port, ulong, NULL, S_IRUGO);
+MODULE_PARM_DESC(port, "I/O port number");
+
+module_param_array(mem, ulong, NULL, S_IRUGO);
+MODULE_PARM_DESC(mem, "I/O memory address");
+
+module_param_array(indirect, byte, NULL, S_IRUGO);
+MODULE_PARM_DESC(indirect, "Indirect access via address and data port");
+
+module_param_array(irq, int, NULL, S_IRUGO);
+MODULE_PARM_DESC(irq, "IRQ number");
+
+module_param_array(clk, int, NULL, S_IRUGO);
+MODULE_PARM_DESC(clk, "External oscillator clock frequency "
+		 "(default=16000000 [16 MHz])");
+
+module_param_array(cdr, byte, NULL, S_IRUGO);
+MODULE_PARM_DESC(cdr, "Clock divider register "
+		 "(default=0x48 [CDR_CBP | CDR_CLK_OFF])");
+
+module_param_array(ocr, byte, NULL, S_IRUGO);
+MODULE_PARM_DESC(ocr, "Output control register "
+		 "(default=0x18 [OCR_TX0_PUSHPULL])");
+
+#define SJA1000_IOSIZE          0x20
+#define SJA1000_IOSIZE_INDIRECT 0x02
+
+static u8 sja1000_isa_mem_read_reg(const struct sja1000_priv *priv, int reg)
+{
+	return readb(priv->reg_base + reg);
+}
+
+static void sja1000_isa_mem_write_reg(const struct sja1000_priv *priv,
+				      int reg, u8 val)
+{
+	writeb(val, priv->reg_base + reg);
+}
+
+static u8 sja1000_isa_port_read_reg(const struct sja1000_priv *priv, int reg)
+{
+	return inb((unsigned long)priv->reg_base + reg);
+}
+
+static void sja1000_isa_port_write_reg(const struct sja1000_priv *priv,
+				       int reg, u8 val)
+{
+	outb(val, (unsigned long)priv->reg_base + reg);
+}
+
+static u8 sja1000_isa_port_read_reg_indirect(const struct sja1000_priv *priv,
+					     int reg)
+{
+	unsigned long base = (unsigned long)priv->reg_base;
+
+	outb(reg, base);
+	return inb(base + 1);
+}
+
+static void sja1000_isa_port_write_reg_indirect(const struct sja1000_priv *priv,
+						int reg, u8 val)
+{
+	unsigned long base = (unsigned long)priv->reg_base;
+
+	outb(reg, base);
+	outb(val, base + 1);
+}
+
+static int __devinit sja1000_isa_match(struct device *pdev, unsigned int idx)
+{
+	if (port[idx] || mem[idx]) {
+		if (irq[idx])
+			return 1;
+	} else if (idx)
+		return 0;
+
+	dev_err(pdev, "insufficient parameters supplied\n");
+	return 0;
+}
+
+static int __devinit sja1000_isa_probe(struct device *pdev, unsigned int idx)
+{
+	struct net_device *dev;
+	struct sja1000_priv *priv;
+	void __iomem *base = NULL;
+	int iosize = SJA1000_IOSIZE;
+	int err;
+
+	if (mem[idx]) {
+		if (!request_mem_region(mem[idx], iosize, DRV_NAME)) {
+			err = -EBUSY;
+			goto exit;
+		}
+		base = ioremap_nocache(mem[idx], iosize);
+		if (!base) {
+			err = -ENOMEM;
+			goto exit_release;
+		}
+	} else {
+		if (indirect[idx] > 0 ||
+		    (indirect[idx] == -1 && indirect[0] > 0))
+			iosize = SJA1000_IOSIZE_INDIRECT;
+		if (!request_region(port[idx], iosize, DRV_NAME)) {
+			err = -EBUSY;
+			goto exit;
+		}
+	}
+
+	dev = alloc_sja1000dev(0);
+	if (!dev) {
+		err = -ENOMEM;
+		goto exit_unmap;
+	}
+	priv = netdev_priv(dev);
+
+	dev->irq = irq[idx];
+	priv->irq_flags = IRQF_SHARED;
+	if (mem[idx]) {
+		priv->reg_base = base;
+		dev->base_addr = mem[idx];
+		priv->read_reg = sja1000_isa_mem_read_reg;
+		priv->write_reg = sja1000_isa_mem_write_reg;
+	} else {
+		priv->reg_base = (void __iomem *)port[idx];
+		dev->base_addr = port[idx];
+
+		if (iosize == SJA1000_IOSIZE_INDIRECT) {
+			priv->read_reg = sja1000_isa_port_read_reg_indirect;
+			priv->write_reg = sja1000_isa_port_write_reg_indirect;
+		} else {
+			priv->read_reg = sja1000_isa_port_read_reg;
+			priv->write_reg = sja1000_isa_port_write_reg;
+		}
+	}
+
+	if (clk[idx])
+		priv->can.clock.freq = clk[idx] / 2;
+	else if (clk[0])
+		priv->can.clock.freq = clk[0] / 2;
+	else
+		priv->can.clock.freq = CLK_DEFAULT / 2;
+
+	if (ocr[idx] != -1)
+		priv->ocr = ocr[idx] & 0xff;
+	else if (ocr[0] != -1)
+		priv->ocr = ocr[0] & 0xff;
+	else
+		priv->ocr = OCR_DEFAULT;
+
+	if (cdr[idx] != -1)
+		priv->cdr = cdr[idx] & 0xff;
+	else if (cdr[0] != -1)
+		priv->cdr = cdr[0] & 0xff;
+	else
+		priv->cdr = CDR_DEFAULT;
+
+	dev_set_drvdata(pdev, dev);
+	SET_NETDEV_DEV(dev, pdev);
+
+	err = register_sja1000dev(dev);
+	if (err) {
+		dev_err(pdev, "registering %s failed (err=%d)\n",
+			DRV_NAME, err);
+		goto exit_unmap;
+	}
+
+	dev_info(pdev, "%s device registered (reg_base=0x%p, irq=%d)\n",
+		 DRV_NAME, priv->reg_base, dev->irq);
+	return 0;
+
+ exit_unmap:
+	if (mem[idx])
+		iounmap(base);
+ exit_release:
+	if (mem[idx])
+		release_mem_region(mem[idx], iosize);
+	else
+		release_region(port[idx], iosize);
+ exit:
+	return err;
+}
+
+static int __devexit sja1000_isa_remove(struct device *pdev, unsigned int idx)
+{
+	struct net_device *dev = dev_get_drvdata(pdev);
+	struct sja1000_priv *priv = netdev_priv(dev);
+
+	unregister_sja1000dev(dev);
+	dev_set_drvdata(pdev, NULL);
+
+	if (mem[idx]) {
+		iounmap(priv->reg_base);
+		release_mem_region(mem[idx], SJA1000_IOSIZE);
+	} else {
+		if (priv->read_reg == sja1000_isa_port_read_reg_indirect)
+			release_region(port[idx], SJA1000_IOSIZE_INDIRECT);
+		else
+			release_region(port[idx], SJA1000_IOSIZE);
+	}
+	free_sja1000dev(dev);
+
+	return 0;
+}
+
+static struct isa_driver sja1000_isa_driver = {
+	.match = sja1000_isa_match,
+	.probe = sja1000_isa_probe,
+	.remove = __devexit_p(sja1000_isa_remove),
+	.driver = {
+		.name = DRV_NAME,
+	},
+};
+
+static int __init sja1000_isa_init(void)
+{
+	int err = isa_register_driver(&sja1000_isa_driver, MAXDEV);
+
+	if (!err)
+		printk(KERN_INFO
+		       "Legacy %s driver for max. %d devices registered\n",
+		       DRV_NAME, MAXDEV);
+	return err;
+}
+
+static void __exit sja1000_isa_exit(void)
+{
+	isa_unregister_driver(&sja1000_isa_driver);
+}
+
+module_init(sja1000_isa_init);
+module_exit(sja1000_isa_exit);