drivers/net/can/sja1000/ems_pcmcia.c

   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
  30 MODULE_AUTHOR("Markus Plessing <plessing@ems-wuensche.com>");
  31 MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-CARD cards");
  32 MODULE_SUPPORTED_DEVICE("EMS CPC-CARD CAN card");
  33 MODULE_LICENSE("GPL v2");
  34
  35 #define EMS_PCMCIA_MAX_CHAN 2
  36
  37 struct 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
  71 static 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
  77 MODULE_DEVICE_TABLE(pcmcia, ems_pcmcia_tbl);
  78
  79 static u8 ems_pcmcia_read_reg(const struct sja1000_priv *priv, int port)
  80 {
  81         return readb(priv->reg_base + port);
  82 }
  83
  84 static 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
  90 static 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  */
 126 static 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
 139 static 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  */
 169 static 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
 215                 priv->irq_flags = IRQF_SHARED;
 216                 dev->irq = pdev->irq;
 217                 priv->reg_base = card->base_addr + EMS_PCMCIA_CAN_BASE_OFFSET +
 218                         (i * EMS_PCMCIA_CAN_CTRL_SIZE);
 219
 220                 /* Check if channel is present */
 221                 if (ems_pcmcia_check_chan(priv)) {
 222                         priv->read_reg  = ems_pcmcia_read_reg;
 223                         priv->write_reg = ems_pcmcia_write_reg;
 224                         priv->can.clock.freq = EMS_PCMCIA_CAN_CLOCK;
 225                         priv->ocr = EMS_PCMCIA_OCR;
 226                         priv->cdr = EMS_PCMCIA_CDR;
 227                         priv->flags |= SJA1000_CUSTOM_IRQ_HANDLER;
 228
 229                         /* Register SJA1000 device */
 230                         err = register_sja1000dev(dev);
 231                         if (err) {
 232                                 free_sja1000dev(dev);
 233                                 goto failure_cleanup;
 234                         }
 235
 236                         card->channels++;
 237
 238                         printk(KERN_INFO "%s: registered %s on channel "
 239                                "#%d at 0x%p, irq %d\n", DRV_NAME, dev->name,
 240                                i, priv->reg_base, dev->irq);
 241                 } else
 242                         free_sja1000dev(dev);
 243         }
 244
 245         err = request_irq(dev->irq, &ems_pcmcia_interrupt, IRQF_SHARED,
 246                           DRV_NAME, card);
 247         if (!err)
 248                 return 0;
 249
 250 failure_cleanup:
 251         ems_pcmcia_del_card(pdev);
 252         return err;
 253 }
 254
 255 /*
 256  * Setup PCMCIA socket and probe for EMS CPC-CARD
 257  */
 258 static int ems_pcmcia_probe(struct pcmcia_device *dev)
 259 {
 260         int csval;
 261
 262         /* General socket configuration */
 263         dev->config_flags |= CONF_ENABLE_IRQ;
 264         dev->config_index = 1;
 265         dev->config_regs = PRESENT_OPTION;
 266
 267         /* The io structure describes IO port mapping */
 268         dev->resource[0]->end = 16;
 269         dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
 270         dev->resource[1]->end = 16;
 271         dev->resource[1]->flags |= IO_DATA_PATH_WIDTH_16;
 272         dev->io_lines = 5;
 273
 274         /* Allocate a memory window */
 275         dev->resource[2]->flags =
 276                 (WIN_DATA_WIDTH_8 | WIN_MEMORY_TYPE_CM | WIN_ENABLE);
 277         dev->resource[2]->start = dev->resource[2]->end = 0;
 278
 279         csval = pcmcia_request_window(dev, dev->resource[2], 0);
 280         if (csval) {
 281                 dev_err(&dev->dev, "pcmcia_request_window failed (err=%d)\n",
 282                         csval);
 283                 return 0;
 284         }
 285
 286         csval = pcmcia_map_mem_page(dev, dev->resource[2], dev->config_base);
 287         if (csval) {
 288                 dev_err(&dev->dev, "pcmcia_map_mem_page failed (err=%d)\n",
 289                         csval);
 290                 return 0;
 291         }
 292
 293         csval = pcmcia_enable_device(dev);
 294         if (csval) {
 295                 dev_err(&dev->dev, "pcmcia_enable_device failed (err=%d)\n",
 296                         csval);
 297                 return 0;
 298         }
 299
 300         ems_pcmcia_add_card(dev, dev->resource[2]->start);
 301         return 0;
 302 }
 303
 304 /*
 305  * Release claimed resources
 306  */
 307 static void ems_pcmcia_remove(struct pcmcia_device *dev)
 308 {
 309         ems_pcmcia_del_card(dev);
 310         pcmcia_disable_device(dev);
 311 }
 312
 313 static struct pcmcia_driver ems_pcmcia_driver = {
 314         .name = DRV_NAME,
 315         .probe = ems_pcmcia_probe,
 316         .remove = ems_pcmcia_remove,
 317         .id_table = ems_pcmcia_tbl,
 318 };
 319 module_pcmcia_driver(ems_pcmcia_driver);