Re: [PATCH v2 5/7] [PATCH 5/8] can: SJA1000 generic platform bus driver

[Sascha Hauer <s.hauer@pengutronix.de>]

Hi Wolfgang,

some comments inline.

Sascha

On Tue, May 12, 2009 at 11:28:02AM +0200, Wolfgang Grandegger wrote:
> This driver adds support for the SJA1000 chips connected to the
> "platform bus", which can be found on various embedded systems.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
> ---
>  drivers/net/can/Kconfig                    |   10 +
>  drivers/net/can/sja1000/Makefile           |    1 
>  drivers/net/can/sja1000/sja1000_platform.c |  169 +++++++++++++++++++++++++++++
>  include/linux/can/platform/sja1000.h       |   32 +++++
>  4 files changed, 212 insertions(+)
>  create mode 100644 drivers/net/can/sja1000/sja1000_platform.c
>  create mode 100644 include/linux/can/platform/sja1000.h
> 
> Index: net-next-2.6/drivers/net/can/Kconfig
> ===================================================================
> --- net-next-2.6.orig/drivers/net/can/Kconfig	2009-05-12 10:47:25.747720647 +0200
> +++ net-next-2.6/drivers/net/can/Kconfig	2009-05-12 10:47:26.411720627 +0200
> @@ -41,6 +41,16 @@
>  	---help---
>  	  Driver for the SJA1000 CAN controllers from Philips or NXP
>  
> +config CAN_SJA1000_PLATFORM
> +	depends on CAN_SJA1000
> +	tristate "Generic Platform Bus based SJA1000 driver"
> +	---help---
> +	  This driver adds support for the SJA1000 chips connected to
> +	  the "platform bus" (Linux abstraction for directly to the
> +	  processor attached devices).  Which can be found on various
> +	  boards from Phytec (http://www.phytec.de) like the PCM027,
> +	  PCM038.
> +
>  config CAN_DEBUG_DEVICES
>  	bool "CAN devices debugging messages"
>  	depends on CAN
> Index: net-next-2.6/drivers/net/can/sja1000/Makefile
> ===================================================================
> --- net-next-2.6.orig/drivers/net/can/sja1000/Makefile	2009-05-12 10:47:25.753720385 +0200
> +++ net-next-2.6/drivers/net/can/sja1000/Makefile	2009-05-12 10:47:26.412720490 +0200
> @@ -3,5 +3,6 @@
>  #
>  
>  obj-$(CONFIG_CAN_SJA1000) += sja1000.o
> +obj-$(CONFIG_CAN_SJA1000_PLATFORM) += sja1000_platform.o
>  
>  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
> Index: net-next-2.6/drivers/net/can/sja1000/sja1000_platform.c
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ net-next-2.6/drivers/net/can/sja1000/sja1000_platform.c	2009-05-12 10:47:26.416720502 +0200
> @@ -0,0 +1,169 @@
> +/*
> + * Copyright (C) 2005 Sascha Hauer, Pengutronix
> + * Copyright (C) 2007 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/interrupt.h>
> +#include <linux/netdevice.h>
> +#include <linux/delay.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/irq.h>
> +#include <linux/can.h>
> +#include <linux/can/dev.h>
> +#include <linux/can/platform/sja1000.h>
> +#include <linux/io.h>
> +
> +#include "sja1000.h"
> +
> +#define DRV_NAME "sja1000_platform"
> +
> +MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
> +MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
> +MODULE_LICENSE("GPL v2");
> +
> +static u8 sp_read_reg(const struct net_device *dev, int reg)
> +{
> +	return ioread8((void __iomem *)(dev->base_addr + reg));
> +}
> +
> +static void sp_write_reg(const struct net_device *dev, int reg, u8 val)
> +{
> +	iowrite8(val, (void __iomem *)(dev->base_addr + reg));
> +}
> +
> +static int sp_probe(struct platform_device *pdev)
> +{
> +	int err, irq;
> +	void __iomem *addr;
> +	struct net_device *dev;
> +	struct sja1000_priv *priv;
> +	struct resource *res_mem, *res_irq;
> +	struct sja1000_platform_data *pdata;
> +
> +	pdata = pdev->dev.platform_data;
> +	if (!pdata) {
> +		dev_err(&pdev->dev, "No platform data provided!\n");
> +		err = -ENODEV;
> +		goto exit;
> +	}
> +
> +	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> +	if (!res_mem || !res_irq) {
> +		err = -ENODEV;
> +		goto exit;
> +	}
> +
> +	if (!request_mem_region(res_mem->start,
> +				res_mem->end - res_mem->start + 1,
> +				DRV_NAME)) {

resource_size(res_mem) please, also for the other occurrences in this
file

> +		err = -EBUSY;
> +		goto exit;
> +	}
> +
> +	addr = ioremap_nocache(res_mem->start,
> +			       res_mem->end - res_mem->start + 1);
> +	if (!addr) {
> +		err = -ENOMEM;
> +		goto exit_release;
> +	}
> +
> +	irq = res_irq->start;
> +	if (res_irq->flags & IRQF_TRIGGER_MASK)
> +		set_irq_type(irq, res_irq->flags & IRQF_TRIGGER_MASK);

You shouldn't use set_irq_type on not yet requested irqs but instead
pass the flags to the real driver and pass them in request_irq.

> +
> +	dev = alloc_sja1000dev(0);
> +	if (!dev) {
> +		err = -ENOMEM;
> +		goto exit_iounmap;
> +	}
> +	priv = netdev_priv(dev);
> +
> +	priv->read_reg = sp_read_reg;
> +	priv->write_reg = sp_write_reg;
> +	priv->can.clock.freq = pdata->clock;
> +	priv->ocr = pdata->ocr;
> +	priv->cdr = pdata->cdr;
> +
> +	dev->irq = irq;
> +	dev->base_addr = (unsigned long)addr;
> +
> +	dev_set_drvdata(&pdev->dev, dev);
> +	SET_NETDEV_DEV(dev, &pdev->dev);
> +
> +	err = register_sja1000dev(dev);
> +	if (err) {
> +		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
> +			DRV_NAME, err);
> +		goto exit_free;
> +	}
> +
> +	dev_info(&pdev->dev, "%s device registered (base_addr=%#lx, irq=%d)\n",
> +		 DRV_NAME, dev->base_addr, dev->irq);

dev_info will already print the driver name twice, printing DRV_NAME
again seems unnecessary.

> +	return 0;
> +
> + exit_free:
> +	free_sja1000dev(dev);
> + exit_iounmap:
> +	iounmap(addr);
> + exit_release:
> +	release_mem_region(res_mem->start, res_mem->end - res_mem->start + 1);
> + exit:
> +	return err;
> +}
> +
> +static int sp_remove(struct platform_device *pdev)
> +{
> +	struct net_device *dev = dev_get_drvdata(&pdev->dev);
> +	struct resource *res;
> +
> +	unregister_sja1000dev(dev);
> +	dev_set_drvdata(&pdev->dev, NULL);
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	release_mem_region(res->start, res->end - res->start + 1);
> +
> +	if (dev->base_addr)
> +		iounmap((void __iomem *)dev->base_addr);
> +
> +	free_sja1000dev(dev);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver sp_driver = {
> +	.probe = sp_probe,
> +	.remove = sp_remove,
> +	.driver = {
> +		.name = DRV_NAME,
> +		.owner = THIS_MODULE,
> +	},
> +};
> +
> +static int __init sp_init(void)
> +{
> +	return platform_driver_register(&sp_driver);
> +}
> +
> +static void __exit sp_exit(void)
> +{
> +	platform_driver_unregister(&sp_driver);
> +}
> +
> +module_init(sp_init);
> +module_exit(sp_exit);
> Index: net-next-2.6/include/linux/can/platform/sja1000.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ net-next-2.6/include/linux/can/platform/sja1000.h	2009-05-12 10:47:26.419720650 +0200
> @@ -0,0 +1,32 @@
> +#ifndef _CAN_PLATFORM_SJA1000_H_
> +#define _CAN_PLATFORM_SJA1000_H_
> +
> +/* clock divider register */
> +#define CDR_CLKOUT_MASK 0x07
> +#define CDR_CLK_OFF	0x08 /* Clock off (CLKOUT pin) */
> +#define CDR_RXINPEN	0x20 /* TX1 output is RX irq output */
> +#define CDR_CBP		0x40 /* CAN input comparator bypass */
> +#define CDR_PELICAN	0x80 /* PeliCAN mode */
> +
> +/* output control register */
> +#define OCR_MODE_BIPHASE  0x00
> +#define OCR_MODE_TEST     0x01
> +#define OCR_MODE_NORMAL   0x02
> +#define OCR_MODE_CLOCK    0x03
> +#define OCR_TX0_INVERT    0x04
> +#define OCR_TX0_PULLDOWN  0x08
> +#define OCR_TX0_PULLUP    0x10
> +#define OCR_TX0_PUSHPULL  0x18
> +#define OCR_TX1_INVERT    0x20
> +#define OCR_TX1_PULLDOWN  0x40
> +#define OCR_TX1_PULLUP    0x80
> +#define OCR_TX1_PUSHPULL  0xc0
> +
> +struct sja1000_platform_data {
> +	u32 clock;	/* CAN bus oscillator frequency in Hz */
> +
> +	u8 ocr;		/* output control register */
> +	u8 cdr;		/* clock divider register */
> +};
> +
> +#endif	/* !_CAN_PLATFORM_SJA1000_H_ */
> 
> 

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