Date:	Fri, 23 Sep 2011 19:32:46 +0200
From:	Wolfram Sang <w.sang@...gutronix.de>
To:	Oliver Hartkopp <socketcan@...tkopp.net>
Cc:	David Miller <davem@...emloft.net>,
	SocketCAN Core Mailing List <socketcan-core@...ts.berlios.de>,
	Linux Netdev List <netdev@...r.kernel.org>,
	Markus Plessing <plessing@...-wuensche.com>,
	Wolfgang Grandegger <wg@...ndegger.com>,
	linux-pcmcia@...ts.infradead.org
Subject: Re: [PATCH net-next] can/sja1000: add driver for EMS PCMCIA card

CCing pcmcia-devel...

On Fri, Sep 23, 2011 at 06:59:48PM +0200, Oliver Hartkopp wrote:
> This patch adds the driver for the SJA1000 based PCMCIA card 'CPC-Card' from
> EMS Dr. Thomas Wuensche (http://www.ems-wuensche.de).
> 
> Signed-off-by: Oliver Hartkopp <socketcan@...tkopp.net>
> 
> ---
> 
> diff -u -r -N a/drivers/net/can/sja1000/Kconfig b/drivers/net/can/sja1000/Kconfig
> --- a/drivers/net/can/sja1000/Kconfig	2011-09-23 18:02:35.711750820 +0200
> +++ b/drivers/net/can/sja1000/Kconfig	2011-09-23 18:02:28.695751113 +0200
> @@ -29,6 +29,13 @@
>  	  OpenFirmware bindings, e.g. if you have a PowerPC based system
>  	  you may want to enable this option.
>  
> +config CAN_EMS_PCMCIA
> +	tristate "EMS CPC-CARD Card"
> +	depends on PCMCIA
> +	---help---
> +	  This driver is for the one or two channel CPC-CARD cards from
> +	  EMS Dr. Thomas Wuensche (http://www.ems-wuensche.de).
> +
>  config CAN_EMS_PCI
>  	tristate "EMS CPC-PCI, CPC-PCIe and CPC-104P Card"
>  	depends on PCI
> diff -u -r -N a/drivers/net/can/sja1000/Makefile b/drivers/net/can/sja1000/Makefile
> --- a/drivers/net/can/sja1000/Makefile	2011-09-23 18:02:38.595750534 +0200
> +++ b/drivers/net/can/sja1000/Makefile	2011-09-23 18:02:28.695751113 +0200
> @@ -6,6 +6,7 @@
>  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_PCMCIA) += ems_pcmcia.o
>  obj-$(CONFIG_CAN_EMS_PCI) += ems_pci.o
>  obj-$(CONFIG_CAN_KVASER_PCI) += kvaser_pci.o
>  obj-$(CONFIG_CAN_PEAK_PCI) += peak_pci.o
> diff -u -r -N a/drivers/net/can/sja1000/ems_pcmcia.c b/drivers/net/can/sja1000/ems_pcmcia.c
> --- a/drivers/net/can/sja1000/ems_pcmcia.c	1970-01-01 01:00:00.000000000 +0100
> +++ b/drivers/net/can/sja1000/ems_pcmcia.c	2011-09-23 18:13:59.227726972 +0200
> @@ -0,0 +1,331 @@
> +/*
> + * Copyright (C) 2008 Sebastian Haas (initial chardev implementation)
> + * Copyright (C) 2010 Markus Plessing <plessing@...-wuensche.com>
> + * Rework for mainline by Oliver Hartkopp <socketcan@...tkopp.net>
> + *
> + * 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.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/netdevice.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <pcmcia/cistpl.h>
> +#include <pcmcia/ds.h>
> +#include <linux/can.h>
> +#include <linux/can/dev.h>
> +#include "sja1000.h"
> +
> +#define DRV_NAME "ems_pcmcia"
> +
> +MODULE_AUTHOR("Markus Plessing <plessing@...-wuensche.com>");
> +MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-CARD cards");
> +MODULE_SUPPORTED_DEVICE("EMS CPC-CARD CAN card");
> +MODULE_LICENSE("GPL v2");
> +
> +#define EMS_PCMCIA_MAX_CHAN 2
> +
> +struct ems_pcmcia_card {
> +	int channels;
> +	struct pcmcia_device *pcmcia_dev;
> +	struct net_device *net_dev[EMS_PCMCIA_MAX_CHAN];
> +	void __iomem *base_addr;
> +};
> +
> +#define EMS_PCMCIA_CAN_CLOCK (16000000 / 2)
> +
> +/*
> + * The board configuration is probably following:
> + * RX1 is connected to ground.
> + * TX1 is not connected.
> + * CLKO is not connected.
> + * Setting the OCR register to 0xDA is a good idea.
> + * This means  normal output mode , push-pull and the correct polarity.
> + */
> +#define EMS_PCMCIA_OCR (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
> +
> +/*
> + * In the CDR register, you should set CBP to 1.
> + * You will probably also want to set the clock divider value to 7
> + * (meaning direct oscillator output) because the second SJA1000 chip
> + * is driven by the first one CLKOUT output.
> + */
> +#define EMS_PCMCIA_CDR (CDR_CBP | CDR_CLKOUT_MASK)
> +#define EMS_PCMCIA_MEM_SIZE 4096 /* Size of the remapped io-memory */
> +#define EMS_PCMCIA_CAN_BASE_OFFSET 0x100 /* Offset where controllers starts */
> +#define EMS_PCMCIA_CAN_CTRL_SIZE 0x80 /* Memory size for each controller */
> +
> +#define EMS_CMD_RESET 0x00 /* Perform a reset of the card */
> +#define EMS_CMD_MAP   0x03 /* Map CAN controllers into card' memory */
> +#define EMS_CMD_UMAP  0x02 /* Unmap CAN controllers from card' memory */
> +
> +static struct pcmcia_device_id ems_pcmcia_tbl[] = {
> +	PCMCIA_DEVICE_PROD_ID123("EMS_T_W", "CPC-Card", "V2.0", 0xeab1ea23,
> +				 0xa338573f, 0xe4575800),
> +	PCMCIA_DEVICE_NULL,
> +};
> +
> +MODULE_DEVICE_TABLE(pcmcia, ems_pcmcia_tbl);
> +
> +static u8 ems_pcmcia_read_reg(const struct sja1000_priv *priv, int port)
> +{
> +	return readb(priv->reg_base + port);
> +}
> +
> +static void ems_pcmcia_write_reg(const struct sja1000_priv *priv, int port,
> +				 u8 val)
> +{
> +	writeb(val, priv->reg_base + port);
> +}
> +
> +static irqreturn_t ems_pcmcia_interrupt(int irq, void *dev_id)
> +{
> +	struct ems_pcmcia_card *card = dev_id;
> +	struct net_device *dev;
> +	irqreturn_t retval = IRQ_NONE;
> +	int i, again;
> +
> +	/* Card not present */
> +	if (readw(card->base_addr) != 0xAA55)
> +		return IRQ_HANDLED;
> +
> +	do {
> +		again = 0;
> +
> +		/* Check interrupt for each channel */
> +		for (i = 0; i < card->channels; i++) {
> +			dev = card->net_dev[i];
> +			if (!dev)
> +				continue;
> +
> +			if (sja1000_interrupt(irq, dev) == IRQ_HANDLED)
> +				again = 1;
> +		}
> +		/* At least one channel handled the interrupt */
> +		if (again)
> +			retval = IRQ_HANDLED;
> +
> +	} while (again);
> +
> +	return retval;
> +}
> +
> +/*
> + * Check if a CAN controller is present at the specified location
> + * by trying to set 'em into the PeliCAN mode
> + */
> +static inline int ems_pcmcia_check_chan(struct sja1000_priv *priv)
> +{
> +	/* Make sure SJA1000 is in reset mode */
> +	ems_pcmcia_write_reg(priv, REG_MOD, 1);
> +	ems_pcmcia_write_reg(priv, REG_CDR, CDR_PELICAN);
> +
> +	/* read reset-values */
> +	if (ems_pcmcia_read_reg(priv, REG_CDR) == CDR_PELICAN)
> +		return 1;
> +
> +	return 0;
> +}
> +
> +static void ems_pcmcia_del_card(struct pcmcia_device *pdev)
> +{
> +	struct ems_pcmcia_card *card = pdev->priv;
> +	struct net_device *dev;
> +	int i;
> +
> +	free_irq(pdev->irq, card);
> +
> +	for (i = 0; i < card->channels; i++) {
> +		dev = card->net_dev[i];
> +		if (!dev)
> +			continue;
> +
> +		printk(KERN_INFO "%s: removing %s on channel #%d\n",
> +		       DRV_NAME, dev->name, i);
> +		unregister_sja1000dev(dev);
> +		free_sja1000dev(dev);
> +	}
> +
> +	writeb(EMS_CMD_UMAP, card->base_addr);
> +	iounmap(card->base_addr);
> +	kfree(card);
> +
> +	pdev->priv = NULL;
> +}
> +
> +/*
> + * Probe PCI device for EMS CAN signature and register each available
> + * CAN channel to SJA1000 Socket-CAN subsystem.
> + */
> +static int __devinit ems_pcmcia_add_card(struct pcmcia_device *pdev,
> +					 unsigned long base)
> +{
> +	struct sja1000_priv *priv;
> +	struct net_device *dev;
> +	struct ems_pcmcia_card *card;
> +	int err, i;
> +
> +	/* Allocating card structures to hold addresses, ... */
> +	card = kzalloc(sizeof(struct ems_pcmcia_card), GFP_KERNEL);
> +	if (!card)
> +		return -ENOMEM;
> +
> +	pdev->priv = card;
> +	card->channels = 0;
> +
> +	card->base_addr = ioremap(base, EMS_PCMCIA_MEM_SIZE);
> +	if (!card->base_addr) {
> +		err = -ENOMEM;
> +		goto failure_cleanup;
> +	}
> +
> +	/* Check for unique EMS CAN signature */
> +	if (readw(card->base_addr) != 0xAA55) {
> +		err = -ENODEV;
> +		goto failure_cleanup;
> +	}
> +
> +	/* Request board reset */
> +	writeb(EMS_CMD_RESET, card->base_addr);
> +
> +	/* Make sure CAN controllers are mapped into card's memory space */
> +	writeb(EMS_CMD_MAP, card->base_addr);
> +
> +	/* Detect available channels */
> +	for (i = 0; i < EMS_PCMCIA_MAX_CHAN; i++) {
> +		dev = alloc_sja1000dev(0);
> +		if (!dev) {
> +			err = -ENOMEM;
> +			goto failure_cleanup;
> +		}
> +
> +		card->net_dev[i] = dev;
> +		priv = netdev_priv(dev);
> +		priv->priv = card;
> +		SET_NETDEV_DEV(dev, &pdev->dev);
> +
> +		priv->irq_flags = IRQF_SHARED;
> +		dev->irq = pdev->irq;
> +		priv->reg_base = card->base_addr + EMS_PCMCIA_CAN_BASE_OFFSET +
> +			(i * EMS_PCMCIA_CAN_CTRL_SIZE);
> +
> +		/* Check if channel is present */
> +		if (ems_pcmcia_check_chan(priv)) {
> +			priv->read_reg  = ems_pcmcia_read_reg;
> +			priv->write_reg = ems_pcmcia_write_reg;
> +			priv->can.clock.freq = EMS_PCMCIA_CAN_CLOCK;
> +			priv->ocr = EMS_PCMCIA_OCR;
> +			priv->cdr = EMS_PCMCIA_CDR;
> +			priv->flags |= SJA1000_CUSTOM_IRQ_HANDLER;
> +
> +			/* Register SJA1000 device */
> +			err = register_sja1000dev(dev);
> +			if (err) {
> +				free_sja1000dev(dev);
> +				goto failure_cleanup;
> +			}
> +
> +			card->channels++;
> +
> +			printk(KERN_INFO "%s: registered %s on channel "
> +			       "#%d at 0x%p, irq %d\n", DRV_NAME, dev->name,
> +			       i, priv->reg_base, dev->irq);
> +		} else
> +			free_sja1000dev(dev);
> +	}
> +
> +	err = request_irq(dev->irq, &ems_pcmcia_interrupt, IRQF_SHARED,
> +			  DRV_NAME, card);
> +	if (!err)
> +		return 0;
> +
> +failure_cleanup:
> +	ems_pcmcia_del_card(pdev);
> +	return err;
> +}
> +
> +/*
> + * Setup PCMCIA socket and probe for EMS CPC-CARD
> + */
> +static int __devinit ems_pcmcia_probe(struct pcmcia_device *dev)
> +{
> +	int csval;
> +
> +	/* General socket configuration */
> +	dev->config_flags |= CONF_ENABLE_IRQ;
> +	dev->config_index = 1;
> +	dev->config_regs = PRESENT_OPTION;
> +
> +	/* The io structure describes IO port mapping */
> +	dev->resource[0]->end = 16;
> +	dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
> +	dev->resource[1]->end = 16;
> +	dev->resource[1]->flags |= IO_DATA_PATH_WIDTH_16;
> +	dev->io_lines = 5;
> +
> +	/* Allocate a memory window */
> +	dev->resource[2]->flags =
> +		(WIN_DATA_WIDTH_8 | WIN_MEMORY_TYPE_CM | WIN_ENABLE);
> +	dev->resource[2]->start = dev->resource[2]->end = 0;
> +
> +	csval = pcmcia_request_window(dev, dev->resource[2], 0);
> +	if (csval) {
> +		dev_err(&dev->dev, "pcmcia_request_window failed (err=%d)\n",
> +			csval);
> +		return 0;
> +	}
> +
> +	csval = pcmcia_map_mem_page(dev, dev->resource[2], dev->config_base);
> +	if (csval) {
> +		dev_err(&dev->dev, "pcmcia_map_mem_page failed (err=%d)\n",
> +			csval);
> +		return 0;
> +	}
> +
> +	csval = pcmcia_enable_device(dev);
> +	if (csval) {
> +		dev_err(&dev->dev, "pcmcia_enable_device failed (err=%d)\n",
> +			csval);
> +		return 0;
> +	}
> +
> +	ems_pcmcia_add_card(dev, dev->resource[2]->start);
> +	return 0;
> +}
> +
> +/*
> + * Release claimed resources
> + */
> +static void ems_pcmcia_remove(struct pcmcia_device *dev)
> +{
> +	ems_pcmcia_del_card(dev);
> +	pcmcia_disable_device(dev);
> +}
> +
> +static struct pcmcia_driver ems_pcmcia_driver = {
> +	.name = DRV_NAME,
> +	.probe = ems_pcmcia_probe,
> +	.remove = ems_pcmcia_remove,
> +	.id_table = ems_pcmcia_tbl,
> +};
> +
> +static int __init ems_pcmcia_init(void)
> +{
> +	return pcmcia_register_driver(&ems_pcmcia_driver);
> +}
> +module_init(ems_pcmcia_init);
> +
> +static void __exit ems_pcmcia_exit(void)
> +{
> +	pcmcia_unregister_driver(&ems_pcmcia_driver);
> +}
> +module_exit(ems_pcmcia_exit);
> 
> _______________________________________________
> Socketcan-core mailing list
> Socketcan-core@...ts.berlios.de
> https://lists.berlios.de/mailman/listinfo/socketcan-core

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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