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); 349