linux/drivers/net/can/sja1000/ems_pcmcia.c
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   1/*
   2 * Copyright (C) 2008 Sebastian Haas (initial chardev implementation)
   3 * Copyright (C) 2010 Markus Plessing <plessing@ems-wuensche.com>
   4 * Rework for mainline by Oliver Hartkopp <socketcan@hartkopp.net>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the version 2 of the GNU General Public License
   8 * as published by the Free Software Foundation
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13 * GNU General Public License for more details.
  14 */
  15
  16#include <linux/kernel.h>
  17#include <linux/module.h>
  18#include <linux/interrupt.h>
  19#include <linux/netdevice.h>
  20#include <linux/delay.h>
  21#include <linux/io.h>
  22#include <pcmcia/cistpl.h>
  23#include <pcmcia/ds.h>
  24#include <linux/can.h>
  25#include <linux/can/dev.h>
  26#include "sja1000.h"
  27
  28#define DRV_NAME "ems_pcmcia"
  29
  30MODULE_AUTHOR("Markus Plessing <plessing@ems-wuensche.com>");
  31MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-CARD cards");
  32MODULE_SUPPORTED_DEVICE("EMS CPC-CARD CAN card");
  33MODULE_LICENSE("GPL v2");
  34
  35#define EMS_PCMCIA_MAX_CHAN 2
  36
  37struct ems_pcmcia_card {
  38        int channels;
  39        struct pcmcia_device *pcmcia_dev;
  40        struct net_device *net_dev[EMS_PCMCIA_MAX_CHAN];
  41        void __iomem *base_addr;
  42};
  43
  44#define EMS_PCMCIA_CAN_CLOCK (16000000 / 2)
  45
  46/*
  47 * The board configuration is probably following:
  48 * RX1 is connected to ground.
  49 * TX1 is not connected.
  50 * CLKO is not connected.
  51 * Setting the OCR register to 0xDA is a good idea.
  52 * This means  normal output mode , push-pull and the correct polarity.
  53 */
  54#define EMS_PCMCIA_OCR (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
  55
  56/*
  57 * In the CDR register, you should set CBP to 1.
  58 * You will probably also want to set the clock divider value to 7
  59 * (meaning direct oscillator output) because the second SJA1000 chip
  60 * is driven by the first one CLKOUT output.
  61 */
  62#define EMS_PCMCIA_CDR (CDR_CBP | CDR_CLKOUT_MASK)
  63#define EMS_PCMCIA_MEM_SIZE 4096 /* Size of the remapped io-memory */
  64#define EMS_PCMCIA_CAN_BASE_OFFSET 0x100 /* Offset where controllers starts */
  65#define EMS_PCMCIA_CAN_CTRL_SIZE 0x80 /* Memory size for each controller */
  66
  67#define EMS_CMD_RESET 0x00 /* Perform a reset of the card */
  68#define EMS_CMD_MAP   0x03 /* Map CAN controllers into card' memory */
  69#define EMS_CMD_UMAP  0x02 /* Unmap CAN controllers from card' memory */
  70
  71static struct pcmcia_device_id ems_pcmcia_tbl[] = {
  72        PCMCIA_DEVICE_PROD_ID123("EMS_T_W", "CPC-Card", "V2.0", 0xeab1ea23,
  73                                 0xa338573f, 0xe4575800),
  74        PCMCIA_DEVICE_NULL,
  75};
  76
  77MODULE_DEVICE_TABLE(pcmcia, ems_pcmcia_tbl);
  78
  79static u8 ems_pcmcia_read_reg(const struct sja1000_priv *priv, int port)
  80{
  81        return readb(priv->reg_base + port);
  82}
  83
  84static void ems_pcmcia_write_reg(const struct sja1000_priv *priv, int port,
  85                                 u8 val)
  86{
  87        writeb(val, priv->reg_base + port);
  88}
  89
  90static irqreturn_t ems_pcmcia_interrupt(int irq, void *dev_id)
  91{
  92        struct ems_pcmcia_card *card = dev_id;
  93        struct net_device *dev;
  94        irqreturn_t retval = IRQ_NONE;
  95        int i, again;
  96
  97        /* Card not present */
  98        if (readw(card->base_addr) != 0xAA55)
  99                return IRQ_HANDLED;
 100
 101        do {
 102                again = 0;
 103
 104                /* Check interrupt for each channel */
 105                for (i = 0; i < card->channels; i++) {
 106                        dev = card->net_dev[i];
 107                        if (!dev)
 108                                continue;
 109
 110                        if (sja1000_interrupt(irq, dev) == IRQ_HANDLED)
 111                                again = 1;
 112                }
 113                /* At least one channel handled the interrupt */
 114                if (again)
 115                        retval = IRQ_HANDLED;
 116
 117        } while (again);
 118
 119        return retval;
 120}
 121
 122/*
 123 * Check if a CAN controller is present at the specified location
 124 * by trying to set 'em into the PeliCAN mode
 125 */
 126static inline int ems_pcmcia_check_chan(struct sja1000_priv *priv)
 127{
 128        /* Make sure SJA1000 is in reset mode */
 129        ems_pcmcia_write_reg(priv, SJA1000_MOD, 1);
 130        ems_pcmcia_write_reg(priv, SJA1000_CDR, CDR_PELICAN);
 131
 132        /* read reset-values */
 133        if (ems_pcmcia_read_reg(priv, SJA1000_CDR) == CDR_PELICAN)
 134                return 1;
 135
 136        return 0;
 137}
 138
 139static void ems_pcmcia_del_card(struct pcmcia_device *pdev)
 140{
 141        struct ems_pcmcia_card *card = pdev->priv;
 142        struct net_device *dev;
 143        int i;
 144
 145        free_irq(pdev->irq, card);
 146
 147        for (i = 0; i < card->channels; i++) {
 148                dev = card->net_dev[i];
 149                if (!dev)
 150                        continue;
 151
 152                printk(KERN_INFO "%s: removing %s on channel #%d\n",
 153                       DRV_NAME, dev->name, i);
 154                unregister_sja1000dev(dev);
 155                free_sja1000dev(dev);
 156        }
 157
 158        writeb(EMS_CMD_UMAP, card->base_addr);
 159        iounmap(card->base_addr);
 160        kfree(card);
 161
 162        pdev->priv = NULL;
 163}
 164
 165/*
 166 * Probe PCI device for EMS CAN signature and register each available
 167 * CAN channel to SJA1000 Socket-CAN subsystem.
 168 */
 169static int ems_pcmcia_add_card(struct pcmcia_device *pdev, unsigned long base)
 170{
 171        struct sja1000_priv *priv;
 172        struct net_device *dev;
 173        struct ems_pcmcia_card *card;
 174        int err, i;
 175
 176        /* Allocating card structures to hold addresses, ... */
 177        card = kzalloc(sizeof(struct ems_pcmcia_card), GFP_KERNEL);
 178        if (!card)
 179                return -ENOMEM;
 180
 181        pdev->priv = card;
 182        card->channels = 0;
 183
 184        card->base_addr = ioremap(base, EMS_PCMCIA_MEM_SIZE);
 185        if (!card->base_addr) {
 186                err = -ENOMEM;
 187                goto failure_cleanup;
 188        }
 189
 190        /* Check for unique EMS CAN signature */
 191        if (readw(card->base_addr) != 0xAA55) {
 192                err = -ENODEV;
 193                goto failure_cleanup;
 194        }
 195
 196        /* Request board reset */
 197        writeb(EMS_CMD_RESET, card->base_addr);
 198
 199        /* Make sure CAN controllers are mapped into card's memory space */
 200        writeb(EMS_CMD_MAP, card->base_addr);
 201
 202        /* Detect available channels */
 203        for (i = 0; i < EMS_PCMCIA_MAX_CHAN; i++) {
 204                dev = alloc_sja1000dev(0);
 205                if (!dev) {
 206                        err = -ENOMEM;
 207                        goto failure_cleanup;
 208                }
 209
 210                card->net_dev[i] = dev;
 211                priv = netdev_priv(dev);
 212                priv->priv = card;
 213                SET_NETDEV_DEV(dev, &pdev->dev);
 214                dev->dev_id = i;
 215
 216                priv->irq_flags = IRQF_SHARED;
 217                dev->irq = pdev->irq;
 218                priv->reg_base = card->base_addr + EMS_PCMCIA_CAN_BASE_OFFSET +
 219                        (i * EMS_PCMCIA_CAN_CTRL_SIZE);
 220
 221                /* Check if channel is present */
 222                if (ems_pcmcia_check_chan(priv)) {
 223                        priv->read_reg  = ems_pcmcia_read_reg;
 224                        priv->write_reg = ems_pcmcia_write_reg;
 225                        priv->can.clock.freq = EMS_PCMCIA_CAN_CLOCK;
 226                        priv->ocr = EMS_PCMCIA_OCR;
 227                        priv->cdr = EMS_PCMCIA_CDR;
 228                        priv->flags |= SJA1000_CUSTOM_IRQ_HANDLER;
 229
 230                        /* Register SJA1000 device */
 231                        err = register_sja1000dev(dev);
 232                        if (err) {
 233                                free_sja1000dev(dev);
 234                                goto failure_cleanup;
 235                        }
 236
 237                        card->channels++;
 238
 239                        printk(KERN_INFO "%s: registered %s on channel "
 240                               "#%d at 0x%p, irq %d\n", DRV_NAME, dev->name,
 241                               i, priv->reg_base, dev->irq);
 242                } else
 243                        free_sja1000dev(dev);
 244        }
 245
 246        err = request_irq(dev->irq, &ems_pcmcia_interrupt, IRQF_SHARED,
 247                          DRV_NAME, card);
 248        if (!err)
 249                return 0;
 250
 251failure_cleanup:
 252        ems_pcmcia_del_card(pdev);
 253        return err;
 254}
 255
 256/*
 257 * Setup PCMCIA socket and probe for EMS CPC-CARD
 258 */
 259static int ems_pcmcia_probe(struct pcmcia_device *dev)
 260{
 261        int csval;
 262
 263        /* General socket configuration */
 264        dev->config_flags |= CONF_ENABLE_IRQ;
 265        dev->config_index = 1;
 266        dev->config_regs = PRESENT_OPTION;
 267
 268        /* The io structure describes IO port mapping */
 269        dev->resource[0]->end = 16;
 270        dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
 271        dev->resource[1]->end = 16;
 272        dev->resource[1]->flags |= IO_DATA_PATH_WIDTH_16;
 273        dev->io_lines = 5;
 274
 275        /* Allocate a memory window */
 276        dev->resource[2]->flags =
 277                (WIN_DATA_WIDTH_8 | WIN_MEMORY_TYPE_CM | WIN_ENABLE);
 278        dev->resource[2]->start = dev->resource[2]->end = 0;
 279
 280        csval = pcmcia_request_window(dev, dev->resource[2], 0);
 281        if (csval) {
 282                dev_err(&dev->dev, "pcmcia_request_window failed (err=%d)\n",
 283                        csval);
 284                return 0;
 285        }
 286
 287        csval = pcmcia_map_mem_page(dev, dev->resource[2], dev->config_base);
 288        if (csval) {
 289                dev_err(&dev->dev, "pcmcia_map_mem_page failed (err=%d)\n",
 290                        csval);
 291                return 0;
 292        }
 293
 294        csval = pcmcia_enable_device(dev);
 295        if (csval) {
 296                dev_err(&dev->dev, "pcmcia_enable_device failed (err=%d)\n",
 297                        csval);
 298                return 0;
 299        }
 300
 301        ems_pcmcia_add_card(dev, dev->resource[2]->start);
 302        return 0;
 303}
 304
 305/*
 306 * Release claimed resources
 307 */
 308static void ems_pcmcia_remove(struct pcmcia_device *dev)
 309{
 310        ems_pcmcia_del_card(dev);
 311        pcmcia_disable_device(dev);
 312}
 313
 314static struct pcmcia_driver ems_pcmcia_driver = {
 315        .name = DRV_NAME,
 316        .probe = ems_pcmcia_probe,
 317        .remove = ems_pcmcia_remove,
 318        .id_table = ems_pcmcia_tbl,
 319};
 320module_pcmcia_driver(ems_pcmcia_driver);
 321
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