Subject: Re: [PATCH net-next v2 2/4] can: cc770: add legacy ISA bus driver for the CC770 and AN82527

From: Marc Kleine-Budde <[email-masked]>
Date: Mon, 28 Nov 2011 13:09:23 +0100

On 11/25/2011 10:43 AM, Wolfgang Grandegger wrote:
> 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])
>   ocr, 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 <[email-masked]>

Some nitpicking inside.

Marc
> ---
>  drivers/net/can/cc770/Kconfig     |   11 ++
>  drivers/net/can/cc770/Makefile    |    1 +
>  drivers/net/can/cc770/cc770_isa.c |  336 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 348 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/net/can/cc770/cc770_isa.c
> 
> diff --git a/drivers/net/can/cc770/Kconfig b/drivers/net/can/cc770/Kconfig
> index 225131b..28e4d48 100644
> --- a/drivers/net/can/cc770/Kconfig
> +++ b/drivers/net/can/cc770/Kconfig
> @@ -1,3 +1,14 @@
>  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
> diff --git a/drivers/net/can/cc770/Makefile b/drivers/net/can/cc770/Makefile
> index 34e8180..872ecff 100644
> --- a/drivers/net/can/cc770/Makefile
> +++ b/drivers/net/can/cc770/Makefile
> @@ -3,5 +3,6 @@
>  #
>  
>  obj-$(CONFIG_CAN_CC770) += cc770.o
> +obj-$(CONFIG_CAN_CC770_ISA) += cc770_isa.o
>  
>  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
> diff --git a/drivers/net/can/cc770/cc770_isa.c b/drivers/net/can/cc770/cc770_isa.c
> new file mode 100644
> index 0000000..3aaecd5
> --- /dev/null
> +++ b/drivers/net/can/cc770/cc770_isa.c
> @@ -0,0 +1,336 @@
> +/*
> + * Copyright (C) 2009, 2011 Wolfgang Grandegger <[email-masked]>
> + *
> + * 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

Please remove the address.

> + */
> +
> +#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 "cc770.h"
> +
> +#define DRV_NAME "cc770_isa"
> +
> +#define MAXDEV 8
> +
> +MODULE_AUTHOR("Wolfgang Grandegger <[email-masked]>");
> +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, 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 = CC770_IOSIZE_INDIRECT;
> +		if (!request_region(port[idx], iosize, DRV_NAME)) {
> +			err = -EBUSY;
> +			goto exit;
> +		}
> +	}
> +
> +	dev = alloc_cc770dev(0);MAXDEV
> +	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] & 0xff;
> +	} else if (cir[0] != 0xff) {
> +		priv->cpu_interface = cir[0] & 0xff;
> +	} 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] & 0xff;
> +	else if (bcr[0] != 0xff)
> +		priv->bus_config = bcr[0] & 0xff;
bus_config is u8
> +	else
> +		priv->bus_config = BCR_DEFAULT;
> +
> +	if (cor[idx] != 0xff)
> +		priv->clkout = cor[idx];
> +	else if (cor[0] != 0xff)
> +		priv->clkout = cor[0] & 0xff;
> +	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, "registering %s failed (err=%d)\n",
> +			DRV_NAME, err);
> +		goto exit_unmap;
> +	}
> +
> +	dev_info(&pdev->dev, "%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 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 = DRV_NAME,
> +		.owner = THIS_MODULE,
> +	},
> +};
> +
> +static int __init cc770_isa_init(void)
> +{
> +	int idx, err;
> +
> +	for (idx = 0; idx < MAXDEV; idx++) {
ARRAY_SIZE?
> +		if ((port[idx] || mem[idx]) && irq[idx]) {
> +			cc770_isa_devs[idx] =
> +				platform_device_alloc(DRV_NAME, 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("%s: platform device %d: port=%#lx, mem=%#lx, "
> +				 "irq=%d\n",
> +				 DRV_NAME, idx, port[idx], mem[idx], irq[idx]);
> +		} else if (idx == 0 || port[idx] || mem[idx]) {
> +				pr_err("%s: insufficient parameters supplied\n",
> +				       DRV_NAME);
> +				err = -EINVAL;
> +				goto exit_free_devices;
> +		}
> +	}
> +
> +	err = platform_driver_register(&cc770_isa_driver);
> +	if (err)
> +		goto exit_free_devices;
> +
> +	pr_info("Legacy %s driver for max. %d devices registered\n",
> +		DRV_NAME, 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 < MAXDEV; idx++) {
ARRAY_SIZE
> +		if (cc770_isa_devs[idx])
> +			platform_device_unregister(cc770_isa_devs[idx]);
> +	}
> +}
> +module_exit(cc770_isa_exit);

-- 
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