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

Sascha Hauer
2009-05-14T06:46:50Z

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_ */
>
>

--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |