drivers/net/can/sja1000/ems_pcmcia.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2008 Sebastian Haas (initial chardev implementation)
   4  * Copyright (C) 2010 Markus Plessing <plessing@ems-wuensche.com>
   5  * Rework for mainline by Oliver Hartkopp <socketcan@hartkopp.net>
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/netdevice.h>
  12 #include <linux/delay.h>
  13 #include <linux/io.h>
  14 #include <pcmcia/cistpl.h>
  15 #include <pcmcia/ds.h>
  16 #include <linux/can.h>
  17 #include <linux/can/dev.h>
  18 #include "sja1000.h"
  19
  20 #define DRV_NAME "ems_pcmcia"
  21
  22 MODULE_AUTHOR("Markus Plessing <plessing@ems-wuensche.com>");
  23 MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-CARD cards");
  24 MODULE_SUPPORTED_DEVICE("EMS CPC-CARD CAN card");
  25 MODULE_LICENSE("GPL v2");
  26
  27 #define EMS_PCMCIA_MAX_CHAN 2
  28
  29 struct ems_pcmcia_card {
  30         int channels;
  31         struct pcmcia_device *pcmcia_dev;
  32         struct net_device *net_dev[EMS_PCMCIA_MAX_CHAN];
  33         void __iomem *base_addr;
  34 };
  35
  36 #define EMS_PCMCIA_CAN_CLOCK (16000000 / 2)
  37
  38 /*
  39  * The board configuration is probably following:
  40  * RX1 is connected to ground.
  41  * TX1 is not connected.
  42  * CLKO is not connected.
  43  * Setting the OCR register to 0xDA is a good idea.
  44  * This means  normal output mode , push-pull and the correct polarity.
  45  */
  46 #define EMS_PCMCIA_OCR (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)
  47
  48 /*
  49  * In the CDR register, you should set CBP to 1.
  50  * You will probably also want to set the clock divider value to 7
  51  * (meaning direct oscillator output) because the second SJA1000 chip
  52  * is driven by the first one CLKOUT output.
  53  */
  54 #define EMS_PCMCIA_CDR (CDR_CBP | CDR_CLKOUT_MASK)
  55 #define EMS_PCMCIA_MEM_SIZE 4096 /* Size of the remapped io-memory */
  56 #define EMS_PCMCIA_CAN_BASE_OFFSET 0x100 /* Offset where controllers starts */
  57 #define EMS_PCMCIA_CAN_CTRL_SIZE 0x80 /* Memory size for each controller */
  58
  59 #define EMS_CMD_RESET 0x00 /* Perform a reset of the card */
  60 #define EMS_CMD_MAP   0x03 /* Map CAN controllers into card' memory */
  61 #define EMS_CMD_UMAP  0x02 /* Unmap CAN controllers from card' memory */
  62
  63 static struct pcmcia_device_id ems_pcmcia_tbl[] = {
  64         PCMCIA_DEVICE_PROD_ID123("EMS_T_W", "CPC-Card", "V2.0", 0xeab1ea23,
  65                                  0xa338573f, 0xe4575800),
  66         PCMCIA_DEVICE_NULL,
  67 };
  68
  69 MODULE_DEVICE_TABLE(pcmcia, ems_pcmcia_tbl);
  70
  71 static u8 ems_pcmcia_read_reg(const struct sja1000_priv *priv, int port)
  72 {
  73         return readb(priv->reg_base + port);
  74 }
  75
  76 static void ems_pcmcia_write_reg(const struct sja1000_priv *priv, int port,
  77                                  u8 val)
  78 {
  79         writeb(val, priv->reg_base + port);
  80 }
  81
  82 static irqreturn_t ems_pcmcia_interrupt(int irq, void *dev_id)
  83 {
  84         struct ems_pcmcia_card *card = dev_id;
  85         struct net_device *dev;
  86         irqreturn_t retval = IRQ_NONE;
  87         int i, again;
  88
  89         /* Card not present */
  90         if (readw(card->base_addr) != 0xAA55)
  91                 return IRQ_HANDLED;
  92
  93         do {
  94                 again = 0;
  95
  96                 /* Check interrupt for each channel */
  97                 for (i = 0; i < card->channels; i++) {
  98                         dev = card->net_dev[i];
  99                         if (!dev)
 100                                 continue;
 101
 102                         if (sja1000_interrupt(irq, dev) == IRQ_HANDLED)
 103                                 again = 1;
 104                 }
 105                 /* At least one channel handled the interrupt */
 106                 if (again)
 107                         retval = IRQ_HANDLED;
 108
 109         } while (again);
 110
 111         return retval;
 112 }
 113
 114 /*
 115  * Check if a CAN controller is present at the specified location
 116  * by trying to set 'em into the PeliCAN mode
 117  */
 118 static inline int ems_pcmcia_check_chan(struct sja1000_priv *priv)
 119 {
 120         /* Make sure SJA1000 is in reset mode */
 121         ems_pcmcia_write_reg(priv, SJA1000_MOD, 1);
 122         ems_pcmcia_write_reg(priv, SJA1000_CDR, CDR_PELICAN);
 123
 124         /* read reset-values */
 125         if (ems_pcmcia_read_reg(priv, SJA1000_CDR) == CDR_PELICAN)
 126                 return 1;
 127
 128         return 0;
 129 }
 130
 131 static void ems_pcmcia_del_card(struct pcmcia_device *pdev)
 132 {
 133         struct ems_pcmcia_card *card = pdev->priv;
 134         struct net_device *dev;
 135         int i;
 136
 137         free_irq(pdev->irq, card);
 138
 139         for (i = 0; i < card->channels; i++) {
 140                 dev = card->net_dev[i];
 141                 if (!dev)
 142                         continue;
 143
 144                 printk(KERN_INFO "%s: removing %s on channel #%d\n",
 145                        DRV_NAME, dev->name, i);
 146                 unregister_sja1000dev(dev);
 147                 free_sja1000dev(dev);
 148         }
 149
 150         writeb(EMS_CMD_UMAP, card->base_addr);
 151         iounmap(card->base_addr);
 152         kfree(card);
 153
 154         pdev->priv = NULL;
 155 }
 156
 157 /*
 158  * Probe PCI device for EMS CAN signature and register each available
 159  * CAN channel to SJA1000 Socket-CAN subsystem.
 160  */
 161 static int ems_pcmcia_add_card(struct pcmcia_device *pdev, unsigned long base)
 162 {
 163         struct sja1000_priv *priv;
 164         struct net_device *dev;
 165         struct ems_pcmcia_card *card;
 166         int err, i;
 167
 168         /* Allocating card structures to hold addresses, ... */
 169         card = kzalloc(sizeof(struct ems_pcmcia_card), GFP_KERNEL);
 170         if (!card)
 171                 return -ENOMEM;
 172
 173         pdev->priv = card;
 174         card->channels = 0;
 175
 176         card->base_addr = ioremap(base, EMS_PCMCIA_MEM_SIZE);
 177         if (!card->base_addr) {
 178                 err = -ENOMEM;
 179                 goto failure_cleanup;
 180         }
 181
 182         /* Check for unique EMS CAN signature */
 183         if (readw(card->base_addr) != 0xAA55) {
 184                 err = -ENODEV;
 185                 goto failure_cleanup;
 186         }
 187
 188         /* Request board reset */
 189         writeb(EMS_CMD_RESET, card->base_addr);
 190
 191         /* Make sure CAN controllers are mapped into card's memory space */
 192         writeb(EMS_CMD_MAP, card->base_addr);
 193
 194         /* Detect available channels */
 195         for (i = 0; i < EMS_PCMCIA_MAX_CHAN; i++) {
 196                 dev = alloc_sja1000dev(0);
 197                 if (!dev) {
 198                         err = -ENOMEM;
 199                         goto failure_cleanup;
 200                 }
 201
 202                 card->net_dev[i] = dev;
 203                 priv = netdev_priv(dev);
 204                 priv->priv = card;
 205                 SET_NETDEV_DEV(dev, &pdev->dev);
 206                 dev->dev_id = i;
 207
 208                 priv->irq_flags = IRQF_SHARED;
 209                 dev->irq = pdev->irq;
 210                 priv->reg_base = card->base_addr + EMS_PCMCIA_CAN_BASE_OFFSET +
 211                         (i * EMS_PCMCIA_CAN_CTRL_SIZE);
 212
 213                 /* Check if channel is present */
 214                 if (ems_pcmcia_check_chan(priv)) {
 215                         priv->read_reg  = ems_pcmcia_read_reg;
 216                         priv->write_reg = ems_pcmcia_write_reg;
 217                         priv->can.clock.freq = EMS_PCMCIA_CAN_CLOCK;
 218                         priv->ocr = EMS_PCMCIA_OCR;
 219                         priv->cdr = EMS_PCMCIA_CDR;
 220                         priv->flags |= SJA1000_CUSTOM_IRQ_HANDLER;
 221
 222                         /* Register SJA1000 device */
 223                         err = register_sja1000dev(dev);
 224                         if (err) {
 225                                 free_sja1000dev(dev);
 226                                 goto failure_cleanup;
 227                         }
 228
 229                         card->channels++;
 230
 231                         printk(KERN_INFO "%s: registered %s on channel "
 232                                "#%d at 0x%p, irq %d\n", DRV_NAME, dev->name,
 233                                i, priv->reg_base, dev->irq);
 234                 } else
 235                         free_sja1000dev(dev);
 236         }
 237
 238         err = request_irq(dev->irq, &ems_pcmcia_interrupt, IRQF_SHARED,
 239                           DRV_NAME, card);
 240         if (!err)
 241                 return 0;
 242
 243 failure_cleanup:
 244         ems_pcmcia_del_card(pdev);
 245         return err;
 246 }
 247
 248 /*
 249  * Setup PCMCIA socket and probe for EMS CPC-CARD
 250  */
 251 static int ems_pcmcia_probe(struct pcmcia_device *dev)
 252 {
 253         int csval;
 254
 255         /* General socket configuration */
 256         dev->config_flags |= CONF_ENABLE_IRQ;
 257         dev->config_index = 1;
 258         dev->config_regs = PRESENT_OPTION;
 259
 260         /* The io structure describes IO port mapping */
 261         dev->resource[0]->end = 16;
 262         dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
 263         dev->resource[1]->end = 16;
 264         dev->resource[1]->flags |= IO_DATA_PATH_WIDTH_16;
 265         dev->io_lines = 5;
 266
 267         /* Allocate a memory window */
 268         dev->resource[2]->flags =
 269                 (WIN_DATA_WIDTH_8 | WIN_MEMORY_TYPE_CM | WIN_ENABLE);
 270         dev->resource[2]->start = dev->resource[2]->end = 0;
 271
 272         csval = pcmcia_request_window(dev, dev->resource[2], 0);
 273         if (csval) {
 274                 dev_err(&dev->dev, "pcmcia_request_window failed (err=%d)\n",
 275                         csval);
 276                 return 0;
 277         }
 278
 279         csval = pcmcia_map_mem_page(dev, dev->resource[2], dev->config_base);
 280         if (csval) {
 281                 dev_err(&dev->dev, "pcmcia_map_mem_page failed (err=%d)\n",
 282                         csval);
 283                 return 0;
 284         }
 285
 286         csval = pcmcia_enable_device(dev);
 287         if (csval) {
 288                 dev_err(&dev->dev, "pcmcia_enable_device failed (err=%d)\n",
 289                         csval);
 290                 return 0;
 291         }
 292
 293         ems_pcmcia_add_card(dev, dev->resource[2]->start);
 294         return 0;
 295 }
 296
 297 /*
 298  * Release claimed resources
 299  */
 300 static void ems_pcmcia_remove(struct pcmcia_device *dev)
 301 {
 302         ems_pcmcia_del_card(dev);
 303         pcmcia_disable_device(dev);
 304 }
 305
 306 static struct pcmcia_driver ems_pcmcia_driver = {
 307         .name = DRV_NAME,
 308         .probe = ems_pcmcia_probe,
 309         .remove = ems_pcmcia_remove,
 310         .id_table = ems_pcmcia_tbl,
 311 };
 312 module_pcmcia_driver(ems_pcmcia_driver);