drivers/i2c/busses/i2c-elektor.c

   1 /* ------------------------------------------------------------------------- */
   2 /* i2c-elektor.c i2c-hw access for PCF8584 style isa bus adaptes             */
   3 /* ------------------------------------------------------------------------- */
   4 /*   Copyright (C) 1995-97 Simon G. Vogl
   5                    1998-99 Hans Berglund
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.                */
  20 /* ------------------------------------------------------------------------- */
  21
  22 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
  23    Frodo Looijaard <frodol@dds.nl> */
  24
  25 /* Partialy rewriten by Oleg I. Vdovikin for mmapped support of
  26    for Alpha Processor Inc. UP-2000(+) boards */
  27
  28 #include <linux/kernel.h>
  29 #include <linux/ioport.h>
  30 #include <linux/module.h>
  31 #include <linux/delay.h>
  32 #include <linux/slab.h>
  33 #include <linux/init.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/pci.h>
  36 #include <linux/wait.h>
  37
  38 #include <linux/isa.h>
  39 #include <linux/i2c.h>
  40 #include <linux/i2c-algo-pcf.h>
  41
  42 #include <asm/io.h>
  43 #include <asm/irq.h>
  44
  45 #include "../algos/i2c-algo-pcf.h"
  46
  47 #define DEFAULT_BASE 0x330
  48
  49 static int base;
  50 static u8 __iomem *base_iomem;
  51
  52 static int irq;
  53 static int clock  = 0x1c;
  54 static int own    = 0x55;
  55 static int mmapped;
  56
  57 /* vdovikin: removed static struct i2c_pcf_isa gpi; code -
  58   this module in real supports only one device, due to missing arguments
  59   in some functions, called from the algo-pcf module. Sometimes it's
  60   need to be rewriten - but for now just remove this for simpler reading */
  61
  62 static wait_queue_head_t pcf_wait;
  63 static int pcf_pending;
  64 static spinlock_t lock;
  65
  66 static struct i2c_adapter pcf_isa_ops;
  67
  68 /* ----- local functions ---------------------------------------------- */
  69
  70 static void pcf_isa_setbyte(void *data, int ctl, int val)
  71 {
  72         u8 __iomem *address = ctl ? (base_iomem + 1) : base_iomem;
  73
  74         /* enable irq if any specified for serial operation */
  75         if (ctl && irq && (val & I2C_PCF_ESO)) {
  76                 val |= I2C_PCF_ENI;
  77         }
  78
  79         pr_debug("%s: Write %p 0x%02X\n", pcf_isa_ops.name, address, val);
  80         iowrite8(val, address);
  81 #ifdef __alpha__
  82         /* API UP2000 needs some hardware fudging to make the write stick */
  83         iowrite8(val, address);
  84 #endif
  85 }
  86
  87 static int pcf_isa_getbyte(void *data, int ctl)
  88 {
  89         u8 __iomem *address = ctl ? (base_iomem + 1) : base_iomem;
  90         int val = ioread8(address);
  91
  92         pr_debug("%s: Read %p 0x%02X\n", pcf_isa_ops.name, address, val);
  93         return (val);
  94 }
  95
  96 static int pcf_isa_getown(void *data)
  97 {
  98         return (own);
  99 }
 100
 101
 102 static int pcf_isa_getclock(void *data)
 103 {
 104         return (clock);
 105 }
 106
 107 static void pcf_isa_waitforpin(void) {
 108         DEFINE_WAIT(wait);
 109         int timeout = 2;
 110         unsigned long flags;
 111
 112         if (irq > 0) {
 113                 spin_lock_irqsave(&lock, flags);
 114                 if (pcf_pending == 0) {
 115                         spin_unlock_irqrestore(&lock, flags);
 116                         prepare_to_wait(&pcf_wait, &wait, TASK_INTERRUPTIBLE);
 117                         if (schedule_timeout(timeout*HZ)) {
 118                                 spin_lock_irqsave(&lock, flags);
 119                                 if (pcf_pending == 1) {
 120                                         pcf_pending = 0;
 121                                 }
 122                                 spin_unlock_irqrestore(&lock, flags);
 123                         }
 124                         finish_wait(&pcf_wait, &wait);
 125                 } else {
 126                         pcf_pending = 0;
 127                         spin_unlock_irqrestore(&lock, flags);
 128                 }
 129         } else {
 130                 udelay(100);
 131         }
 132 }
 133
 134
 135 static irqreturn_t pcf_isa_handler(int this_irq, void *dev_id) {
 136         spin_lock(&lock);
 137         pcf_pending = 1;
 138         spin_unlock(&lock);
 139         wake_up_interruptible(&pcf_wait);
 140         return IRQ_HANDLED;
 141 }
 142
 143
 144 static int pcf_isa_init(void)
 145 {
 146         spin_lock_init(&lock);
 147         if (!mmapped) {
 148                 if (!request_region(base, 2, pcf_isa_ops.name)) {
 149                         printk(KERN_ERR "%s: requested I/O region (%#x:2) is "
 150                                "in use\n", pcf_isa_ops.name, base);
 151                         return -ENODEV;
 152                 }
 153                 base_iomem = ioport_map(base, 2);
 154                 if (!base_iomem) {
 155                         printk(KERN_ERR "%s: remap of I/O region %#x failed\n",
 156                                pcf_isa_ops.name, base);
 157                         release_region(base, 2);
 158                         return -ENODEV;
 159                 }
 160         } else {
 161                 if (!request_mem_region(base, 2, pcf_isa_ops.name)) {
 162                         printk(KERN_ERR "%s: requested memory region (%#x:2) "
 163                                "is in use\n", pcf_isa_ops.name, base);
 164                         return -ENODEV;
 165                 }
 166                 base_iomem = ioremap(base, 2);
 167                 if (base_iomem == NULL) {
 168                         printk(KERN_ERR "%s: remap of memory region %#x "
 169                                "failed\n", pcf_isa_ops.name, base);
 170                         release_mem_region(base, 2);
 171                         return -ENODEV;
 172                 }
 173         }
 174         pr_debug("%s: registers %#x remapped to %p\n", pcf_isa_ops.name, base,
 175                  base_iomem);
 176
 177         if (irq > 0) {
 178                 if (request_irq(irq, pcf_isa_handler, 0, pcf_isa_ops.name,
 179                                 NULL) < 0) {
 180                         printk(KERN_ERR "%s: Request irq%d failed\n",
 181                                pcf_isa_ops.name, irq);
 182                         irq = 0;
 183                 } else
 184                         enable_irq(irq);
 185         }
 186         return 0;
 187 }
 188
 189 /* ------------------------------------------------------------------------
 190  * Encapsulate the above functions in the correct operations structure.
 191  * This is only done when more than one hardware adapter is supported.
 192  */
 193 static struct i2c_algo_pcf_data pcf_isa_data = {
 194         .setpcf     = pcf_isa_setbyte,
 195         .getpcf     = pcf_isa_getbyte,
 196         .getown     = pcf_isa_getown,
 197         .getclock   = pcf_isa_getclock,
 198         .waitforpin = pcf_isa_waitforpin,
 199 };
 200
 201 static struct i2c_adapter pcf_isa_ops = {
 202         .owner          = THIS_MODULE,
 203         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 204         .id             = I2C_HW_P_ELEK,
 205         .algo_data      = &pcf_isa_data,
 206         .name           = "i2c-elektor",
 207 };
 208
 209 static int __devinit elektor_match(struct device *dev, unsigned int id)
 210 {
 211 #ifdef __alpha__
 212         /* check to see we have memory mapped PCF8584 connected to the
 213         Cypress cy82c693 PCI-ISA bridge as on UP2000 board */
 214         if (base == 0) {
 215                 struct pci_dev *cy693_dev;
 216
 217                 cy693_dev = pci_get_device(PCI_VENDOR_ID_CONTAQ,
 218                                            PCI_DEVICE_ID_CONTAQ_82C693, NULL);
 219                 if (cy693_dev) {
 220                         unsigned char config;
 221                         /* yeap, we've found cypress, let's check config */
 222                         if (!pci_read_config_byte(cy693_dev, 0x47, &config)) {
 223
 224                                 dev_dbg(dev, "found cy82c693, config "
 225                                         "register 0x47 = 0x%02x\n", config);
 226
 227                                 /* UP2000 board has this register set to 0xe1,
 228                                    but the most significant bit as seems can be
 229                                    reset during the proper initialisation
 230                                    sequence if guys from API decides to do that
 231                                    (so, we can even enable Tsunami Pchip
 232                                    window for the upper 1 Gb) */
 233
 234                                 /* so just check for ROMCS at 0xe0000,
 235                                    ROMCS enabled for writes
 236                                    and external XD Bus buffer in use. */
 237                                 if ((config & 0x7f) == 0x61) {
 238                                         /* seems to be UP2000 like board */
 239                                         base = 0xe0000;
 240                                         mmapped = 1;
 241                                         /* UP2000 drives ISA with
 242                                            8.25 MHz (PCI/4) clock
 243                                            (this can be read from cypress) */
 244                                         clock = I2C_PCF_CLK | I2C_PCF_TRNS90;
 245                                         dev_info(dev, "found API UP2000 like "
 246                                                  "board, will probe PCF8584 "
 247                                                  "later\n");
 248                                 }
 249                         }
 250                         pci_dev_put(cy693_dev);
 251                 }
 252         }
 253 #endif
 254
 255         /* sanity checks for mmapped I/O */
 256         if (mmapped && base < 0xc8000) {
 257                 dev_err(dev, "incorrect base address (%#x) specified "
 258                        "for mmapped I/O\n", base);
 259                 return 0;
 260         }
 261
 262         if (base == 0) {
 263                 base = DEFAULT_BASE;
 264         }
 265         return 1;
 266 }
 267
 268 static int __devinit elektor_probe(struct device *dev, unsigned int id)
 269 {
 270         init_waitqueue_head(&pcf_wait);
 271         if (pcf_isa_init())
 272                 return -ENODEV;
 273         pcf_isa_ops.dev.parent = dev;
 274         if (i2c_pcf_add_bus(&pcf_isa_ops) < 0)
 275                 goto fail;
 276
 277         dev_info(dev, "found device at %#x\n", base);
 278
 279         return 0;
 280
 281  fail:
 282         if (irq > 0) {
 283                 disable_irq(irq);
 284                 free_irq(irq, NULL);
 285         }
 286
 287         if (!mmapped) {
 288                 ioport_unmap(base_iomem);
 289                 release_region(base, 2);
 290         } else {
 291                 iounmap(base_iomem);
 292                 release_mem_region(base, 2);
 293         }
 294         return -ENODEV;
 295 }
 296
 297 static int __devexit elektor_remove(struct device *dev, unsigned int id)
 298 {
 299         i2c_del_adapter(&pcf_isa_ops);
 300
 301         if (irq > 0) {
 302                 disable_irq(irq);
 303                 free_irq(irq, NULL);
 304         }
 305
 306         if (!mmapped) {
 307                 ioport_unmap(base_iomem);
 308                 release_region(base, 2);
 309         } else {
 310                 iounmap(base_iomem);
 311                 release_mem_region(base, 2);
 312         }
 313
 314         return 0;
 315 }
 316
 317 static struct isa_driver i2c_elektor_driver = {
 318         .match          = elektor_match,
 319         .probe          = elektor_probe,
 320         .remove         = __devexit_p(elektor_remove),
 321         .driver = {
 322                 .owner  = THIS_MODULE,
 323                 .name   = "i2c-elektor",
 324         },
 325 };
 326
 327 static int __init i2c_pcfisa_init(void)
 328 {
 329         return isa_register_driver(&i2c_elektor_driver, 1);
 330 }
 331
 332 static void __exit i2c_pcfisa_exit(void)
 333 {
 334         isa_unregister_driver(&i2c_elektor_driver);
 335 }
 336
 337 MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
 338 MODULE_DESCRIPTION("I2C-Bus adapter routines for PCF8584 ISA bus adapter");
 339 MODULE_LICENSE("GPL");
 340
 341 module_param(base, int, 0);
 342 module_param(irq, int, 0);
 343 module_param(clock, int, 0);
 344 module_param(own, int, 0);
 345 module_param(mmapped, int, 0);
 346
 347 module_init(i2c_pcfisa_init);
 348 module_exit(i2c_pcfisa_exit);