can: cc770: add legacy ISA bus driver for the CC770 and AN82527

This patch adds support for legacy Bosch CC770 and Intel AN82527 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 cc770_isa.ko port=0x310,0x380 irq=7,11

for ISA devices using I/O ports or:

insmod cc770_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 cc770_isa.ko port=0x310,0x380 indirect=1 irq=7,11

Furthermore, the following mode parameter can be defined:

clk: External oscillator clock frequency (default=16000000 [16 MHz])
cir: CPU interface register (default=0x40 [DSC])
bcr: Bus configuration register (default=0x40 [CBY])
cor: Clockout register (default=0x00)

Note: for clk, cir, bcr and cor, the first argument re-defines the
default for all other devices, e.g.:

insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000

is equivalent to

insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000,24000000

Signed-off-by: Wolfgang Grandegger <[e-mail]>
Acked-by: Marc Kleine-Budde <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/can/cc770/Kconfig

···
 menuconfig CAN_CC770
 	tristate "Bosch CC770 and Intel AN82527 devices"
 	depends on CAN_DEV && HAS_IOMEM
+
+if CAN_CC770
+
+config CAN_CC770_ISA
+	tristate "ISA Bus based legacy CC770 driver"
+	---help---
+	  This driver adds legacy support for CC770 and AN82527 chips
+	  connected to the ISA bus using I/O port, memory mapped or
+	  indirect access.
+
+endif

drivers/net/can/cc770/Makefile

···
 #
 
 obj-$(CONFIG_CAN_CC770) += cc770.o
+obj-$(CONFIG_CAN_CC770_ISA) += cc770_isa.o
 
 ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG

drivers/net/can/cc770/cc770_isa.c

···
+/*
+ * Driver for CC770 and AN82527 CAN controllers on the legacy ISA bus
+ *
+ * Copyright (C) 2009, 2011 Wolfgang Grandegger <[e-mail]>
+ *
+ * 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.
+ */
+
+/*
+ * Bosch CC770 and Intel AN82527 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 cc770_isa.ko port=0x310,0x380 irq=7,11
+ *
+ * for ISA devices using I/O ports or:
+ *
+ *   insmod cc770_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 cc770_isa.ko port=0x310,0x380 indirect=1 irq=7,11
+ *
+ * Furthermore, the following mode parameter can be defined:
+ *
+ *   clk: External oscillator clock frequency (default=16000000 [16 MHz])
+ *   cir: CPU interface register (default=0x40 [DSC])
+ *   bcr: Bus configuration register (default=0x40 [CBY])
+ *   cor: Clockout register (default=0x00)
+ *
+ * Note: for clk, cir, bcr and cor, the first argument re-defines the
+ * default for all other devices, e.g.:
+ *
+ *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000
+ *
+ * is equivalent to
+ *
+ *   insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000,24000000
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.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/cc770.h>
+
+#include "cc770.h"
+
+#define MAXDEV 8
+
+MODULE_AUTHOR("Wolfgang Grandegger <[e-mail]>");
+MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the ISA bus");
+MODULE_LICENSE("GPL v2");
+
+#define CLK_DEFAULT	16000000	/* 16 MHz */
+#define COR_DEFAULT	0x00
+#define BCR_DEFAULT	BUSCFG_CBY
+
+static unsigned long port[MAXDEV];
+static unsigned long mem[MAXDEV];
+static int __devinitdata irq[MAXDEV];
+static int __devinitdata clk[MAXDEV];
+static u8 __devinitdata cir[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
+static u8 __devinitdata cor[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
+static u8 __devinitdata bcr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff};
+static int __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, int, 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(cir, byte, NULL, S_IRUGO);
+MODULE_PARM_DESC(cir, "CPU interface register (default=0x40 [DSC])");
+
+module_param_array(cor, byte, NULL, S_IRUGO);
+MODULE_PARM_DESC(cor, "Clockout register (default=0x00)");
+
+module_param_array(bcr, byte, NULL, S_IRUGO);
+MODULE_PARM_DESC(bcr, "Bus configuration register (default=0x40 [CBY])");
+
+#define CC770_IOSIZE          0x20
+#define CC770_IOSIZE_INDIRECT 0x02
+
+static struct platform_device *cc770_isa_devs[MAXDEV];
+
+static u8 cc770_isa_mem_read_reg(const struct cc770_priv *priv, int reg)
+{
+	return readb(priv->reg_base + reg);
+}
+
+static void cc770_isa_mem_write_reg(const struct cc770_priv *priv,
+				      int reg, u8 val)
+{
+	writeb(val, priv->reg_base + reg);
+}
+
+static u8 cc770_isa_port_read_reg(const struct cc770_priv *priv, int reg)
+{
+	return inb((unsigned long)priv->reg_base + reg);
+}
+
+static void cc770_isa_port_write_reg(const struct cc770_priv *priv,
+				       int reg, u8 val)
+{
+	outb(val, (unsigned long)priv->reg_base + reg);
+}
+
+static u8 cc770_isa_port_read_reg_indirect(const struct cc770_priv *priv,
+					     int reg)
+{
+	unsigned long base = (unsigned long)priv->reg_base;
+
+	outb(reg, base);
+	return inb(base + 1);
+}
+
+static void cc770_isa_port_write_reg_indirect(const struct cc770_priv *priv,
+						int reg, u8 val)
+{
+	unsigned long base = (unsigned long)priv->reg_base;
+
+	outb(reg, base);
+	outb(val, base + 1);
+}
+
+static int __devinit cc770_isa_probe(struct platform_device *pdev)
+{
+	struct net_device *dev;
+	struct cc770_priv *priv;
+	void __iomem *base = NULL;
+	int iosize = CC770_IOSIZE;
+	int idx = pdev->id;
+	int err;
+	u32 clktmp;
+
+	dev_dbg(&pdev->dev, "probing idx=%d: port=%#lx, mem=%#lx, irq=%d\n",
+		idx, port[idx], mem[idx], irq[idx]);
+	if (mem[idx]) {
+		if (!request_mem_region(mem[idx], iosize, KBUILD_MODNAME)) {
+			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 = CC770_IOSIZE_INDIRECT;
+		if (!request_region(port[idx], iosize, KBUILD_MODNAME)) {
+			err = -EBUSY;
+			goto exit;
+		}
+	}
+
+	dev = alloc_cc770dev(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 = cc770_isa_mem_read_reg;
+		priv->write_reg = cc770_isa_mem_write_reg;
+	} else {
+		priv->reg_base = (void __iomem *)port[idx];
+		dev->base_addr = port[idx];
+
+		if (iosize == CC770_IOSIZE_INDIRECT) {
+			priv->read_reg = cc770_isa_port_read_reg_indirect;
+			priv->write_reg = cc770_isa_port_write_reg_indirect;
+		} else {
+			priv->read_reg = cc770_isa_port_read_reg;
+			priv->write_reg = cc770_isa_port_write_reg;
+		}
+	}
+
+	if (clk[idx])
+		clktmp = clk[idx];
+	else if (clk[0])
+		clktmp = clk[0];
+	else
+		clktmp = CLK_DEFAULT;
+	priv->can.clock.freq = clktmp;
+
+	if (cir[idx] != 0xff) {
+		priv->cpu_interface = cir[idx];
+	} else if (cir[0] != 0xff) {
+		priv->cpu_interface = cir[0];
+	} else {
+		/* The system clock may not exceed 10 MHz */
+		if (clktmp > 10000000) {
+			priv->cpu_interface |= CPUIF_DSC;
+			clktmp /= 2;
+		}
+		/* The memory clock may not exceed 8 MHz */
+		if (clktmp > 8000000)
+			priv->cpu_interface |= CPUIF_DMC;
+	}
+
+	if (priv->cpu_interface & CPUIF_DSC)
+		priv->can.clock.freq /= 2;
+
+	if (bcr[idx] != 0xff)
+		priv->bus_config = bcr[idx];
+	else if (bcr[0] != 0xff)
+		priv->bus_config = bcr[0];
+	else
+		priv->bus_config = BCR_DEFAULT;
+
+	if (cor[idx] != 0xff)
+		priv->clkout = cor[idx];
+	else if (cor[0] != 0xff)
+		priv->clkout = cor[0];
+	else
+		priv->clkout = COR_DEFAULT;
+
+	dev_set_drvdata(&pdev->dev, dev);
+	SET_NETDEV_DEV(dev, &pdev->dev);
+
+	err = register_cc770dev(dev);
+	if (err) {
+		dev_err(&pdev->dev,
+			"couldn't register device (err=%d)\n", err);
+		goto exit_unmap;
+	}
+
+	dev_info(&pdev->dev, "device registered (reg_base=0x%p, irq=%d)\n",
+		 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 cc770_isa_remove(struct platform_device *pdev)
+{
+	struct net_device *dev = dev_get_drvdata(&pdev->dev);
+	struct cc770_priv *priv = netdev_priv(dev);
+	int idx = pdev->id;
+
+	unregister_cc770dev(dev);
+	dev_set_drvdata(&pdev->dev, NULL);
+
+	if (mem[idx]) {
+		iounmap(priv->reg_base);
+		release_mem_region(mem[idx], CC770_IOSIZE);
+	} else {
+		if (priv->read_reg == cc770_isa_port_read_reg_indirect)
+			release_region(port[idx], CC770_IOSIZE_INDIRECT);
+		else
+			release_region(port[idx], CC770_IOSIZE);
+	}
+	free_cc770dev(dev);
+
+	return 0;
+}
+
+static struct platform_driver cc770_isa_driver = {
+	.probe = cc770_isa_probe,
+	.remove = __devexit_p(cc770_isa_remove),
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init cc770_isa_init(void)
+{
+	int idx, err;
+
+	for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
+		if ((port[idx] || mem[idx]) && irq[idx]) {
+			cc770_isa_devs[idx] =
+				platform_device_alloc(KBUILD_MODNAME, idx);
+			if (!cc770_isa_devs[idx]) {
+				err = -ENOMEM;
+				goto exit_free_devices;
+			}
+			err = platform_device_add(cc770_isa_devs[idx]);
+			if (err) {
+				platform_device_put(cc770_isa_devs[idx]);
+				goto exit_free_devices;
+			}
+			pr_debug("platform device %d: port=%#lx, mem=%#lx, "
+				 "irq=%d\n",
+				 idx, port[idx], mem[idx], irq[idx]);
+		} else if (idx == 0 || port[idx] || mem[idx]) {
+			pr_err("insufficient parameters supplied\n");
+			err = -EINVAL;
+			goto exit_free_devices;
+		}
+	}
+
+	err = platform_driver_register(&cc770_isa_driver);
+	if (err)
+		goto exit_free_devices;
+
+	pr_info("driver for max. %d devices registered\n", MAXDEV);
+
+	return 0;
+
+exit_free_devices:
+	while (--idx >= 0) {
+		if (cc770_isa_devs[idx])
+			platform_device_unregister(cc770_isa_devs[idx]);
+	}
+
+	return err;
+}
+module_init(cc770_isa_init);
+
+static void __exit cc770_isa_exit(void)
+{
+	int idx;
+
+	platform_driver_unregister(&cc770_isa_driver);
+	for (idx = 0; idx < ARRAY_SIZE(cc770_isa_devs); idx++) {
+		if (cc770_isa_devs[idx])
+			platform_device_unregister(cc770_isa_devs[idx]);
+	}
+}
+module_exit(cc770_isa_exit);