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/init.h> 33 #include <linux/interrupt.h> 34 #include <linux/pci.h> 35 #include <linux/wait.h> 36 37 #include <linux/isa.h> 38 #include <linux/i2c.h> 39 #include <linux/i2c-algo-pcf.h> 40 #include <linux/io.h> 41 42 #include <asm/irq.h> 43 44 #include "../algos/i2c-algo-pcf.h" 45 46 #define DEFAULT_BASE 0x330 47 48 static int base; 49 static u8 __iomem *base_iomem; 50 51 static int irq; 52 static int clock = 0x1c; 53 static int own = 0x55; 54 static int mmapped; 55 56 /* vdovikin: removed static struct i2c_pcf_isa gpi; code - 57 this module in real supports only one device, due to missing arguments 58 in some functions, called from the algo-pcf module. Sometimes it's 59 need to be rewriten - but for now just remove this for simpler reading */ 60 61 static wait_queue_head_t pcf_wait; 62 static int pcf_pending; 63 static spinlock_t lock; 64 65 static struct i2c_adapter pcf_isa_ops; 66 67 /* ----- local functions ---------------------------------------------- */ 68 69 static void pcf_isa_setbyte(void *data, int ctl, int val) 70 { 71 u8 __iomem *address = ctl ? (base_iomem + 1) : base_iomem; 72 73 /* enable irq if any specified for serial operation */ 74 if (ctl && irq && (val & I2C_PCF_ESO)) { 75 val |= I2C_PCF_ENI; 76 } 77 78 pr_debug("%s: Write %p 0x%02X\n", pcf_isa_ops.name, address, val); 79 iowrite8(val, address); 80 #ifdef __alpha__ 81 /* API UP2000 needs some hardware fudging to make the write stick */ 82 iowrite8(val, address); 83 #endif 84 } 85 86 static int pcf_isa_getbyte(void *data, int ctl) 87 { 88 u8 __iomem *address = ctl ? (base_iomem + 1) : base_iomem; 89 int val = ioread8(address); 90 91 pr_debug("%s: Read %p 0x%02X\n", pcf_isa_ops.name, address, val); 92 return (val); 93 } 94 95 static int pcf_isa_getown(void *data) 96 { 97 return (own); 98 } 99 100 101 static int pcf_isa_getclock(void *data) 102 { 103 return (clock); 104 } 105 106 static void pcf_isa_waitforpin(void *data) 107 { 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 .algo_data = &pcf_isa_data, 205 .name = "i2c-elektor", 206 }; 207 208 static int __devinit elektor_match(struct device *dev, unsigned int id) 209 { 210 #ifdef __alpha__ 211 /* check to see we have memory mapped PCF8584 connected to the 212 Cypress cy82c693 PCI-ISA bridge as on UP2000 board */ 213 if (base == 0) { 214 struct pci_dev *cy693_dev; 215 216 cy693_dev = pci_get_device(PCI_VENDOR_ID_CONTAQ, 217 PCI_DEVICE_ID_CONTAQ_82C693, NULL); 218 if (cy693_dev) { 219 unsigned char config; 220 /* yeap, we've found cypress, let's check config */ 221 if (!pci_read_config_byte(cy693_dev, 0x47, &config)) { 222 223 dev_dbg(dev, "found cy82c693, config " 224 "register 0x47 = 0x%02x\n", config); 225 226 /* UP2000 board has this register set to 0xe1, 227 but the most significant bit as seems can be 228 reset during the proper initialisation 229 sequence if guys from API decides to do that 230 (so, we can even enable Tsunami Pchip 231 window for the upper 1 Gb) */ 232 233 /* so just check for ROMCS at 0xe0000, 234 ROMCS enabled for writes 235 and external XD Bus buffer in use. */ 236 if ((config & 0x7f) == 0x61) { 237 /* seems to be UP2000 like board */ 238 base = 0xe0000; 239 mmapped = 1; 240 /* UP2000 drives ISA with 241 8.25 MHz (PCI/4) clock 242 (this can be read from cypress) */ 243 clock = I2C_PCF_CLK | I2C_PCF_TRNS90; 244 dev_info(dev, "found API UP2000 like " 245 "board, will probe PCF8584 " 246 "later\n"); 247 } 248 } 249 pci_dev_put(cy693_dev); 250 } 251 } 252 #endif 253 254 /* sanity checks for mmapped I/O */ 255 if (mmapped && base < 0xc8000) { 256 dev_err(dev, "incorrect base address (%#x) specified " 257 "for mmapped I/O\n", base); 258 return 0; 259 } 260 261 if (base == 0) { 262 base = DEFAULT_BASE; 263 } 264 return 1; 265 } 266 267 static int __devinit elektor_probe(struct device *dev, unsigned int id) 268 { 269 init_waitqueue_head(&pcf_wait); 270 if (pcf_isa_init()) 271 return -ENODEV; 272 pcf_isa_ops.dev.parent = dev; 273 if (i2c_pcf_add_bus(&pcf_isa_ops) < 0) 274 goto fail; 275 276 dev_info(dev, "found device at %#x\n", base); 277 278 return 0; 279 280 fail: 281 if (irq > 0) { 282 disable_irq(irq); 283 free_irq(irq, NULL); 284 } 285 286 if (!mmapped) { 287 ioport_unmap(base_iomem); 288 release_region(base, 2); 289 } else { 290 iounmap(base_iomem); 291 release_mem_region(base, 2); 292 } 293 return -ENODEV; 294 } 295 296 static int __devexit elektor_remove(struct device *dev, unsigned int id) 297 { 298 i2c_del_adapter(&pcf_isa_ops); 299 300 if (irq > 0) { 301 disable_irq(irq); 302 free_irq(irq, NULL); 303 } 304 305 if (!mmapped) { 306 ioport_unmap(base_iomem); 307 release_region(base, 2); 308 } else { 309 iounmap(base_iomem); 310 release_mem_region(base, 2); 311 } 312 313 return 0; 314 } 315 316 static struct isa_driver i2c_elektor_driver = { 317 .match = elektor_match, 318 .probe = elektor_probe, 319 .remove = __devexit_p(elektor_remove), 320 .driver = { 321 .owner = THIS_MODULE, 322 .name = "i2c-elektor", 323 }, 324 }; 325 326 static int __init i2c_pcfisa_init(void) 327 { 328 return isa_register_driver(&i2c_elektor_driver, 1); 329 } 330 331 static void __exit i2c_pcfisa_exit(void) 332 { 333 isa_unregister_driver(&i2c_elektor_driver); 334 } 335 336 MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>"); 337 MODULE_DESCRIPTION("I2C-Bus adapter routines for PCF8584 ISA bus adapter"); 338 MODULE_LICENSE("GPL"); 339 340 module_param(base, int, 0); 341 module_param(irq, int, 0); 342 module_param(clock, int, 0); 343 module_param(own, int, 0); 344 module_param(mmapped, int, 0); 345 346 module_init(i2c_pcfisa_init); 347 module_exit(i2c_pcfisa_exit); 348