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 Ky�sti M�lkki <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/i2c.h> 39 #include <linux/i2c-algo-pcf.h> 40 41 #include <asm/io.h> 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 int irq; 50 static int clock = 0x1c; 51 static int own = 0x55; 52 static int mmapped; 53 54 /* vdovikin: removed static struct i2c_pcf_isa gpi; code - 55 this module in real supports only one device, due to missing arguments 56 in some functions, called from the algo-pcf module. Sometimes it's 57 need to be rewriten - but for now just remove this for simpler reading */ 58 59 static wait_queue_head_t pcf_wait; 60 static int pcf_pending; 61 static spinlock_t lock; 62 63 /* ----- local functions ---------------------------------------------- */ 64 65 static void pcf_isa_setbyte(void *data, int ctl, int val) 66 { 67 int address = ctl ? (base + 1) : base; 68 69 /* enable irq if any specified for serial operation */ 70 if (ctl && irq && (val & I2C_PCF_ESO)) { 71 val |= I2C_PCF_ENI; 72 } 73 74 pr_debug("i2c-elektor: Write 0x%X 0x%02X\n", address, val & 255); 75 76 switch (mmapped) { 77 case 0: /* regular I/O */ 78 outb(val, address); 79 break; 80 case 2: /* double mapped I/O needed for UP2000 board, 81 I don't know why this... */ 82 writeb(val, (void *)address); 83 /* fall */ 84 case 1: /* memory mapped I/O */ 85 writeb(val, (void *)address); 86 break; 87 } 88 } 89 90 static int pcf_isa_getbyte(void *data, int ctl) 91 { 92 int address = ctl ? (base + 1) : base; 93 int val = mmapped ? readb((void *)address) : inb(address); 94 95 pr_debug("i2c-elektor: Read 0x%X 0x%02X\n", address, val); 96 97 return (val); 98 } 99 100 static int pcf_isa_getown(void *data) 101 { 102 return (own); 103 } 104 105 106 static int pcf_isa_getclock(void *data) 107 { 108 return (clock); 109 } 110 111 static void pcf_isa_waitforpin(void) { 112 DEFINE_WAIT(wait); 113 int timeout = 2; 114 unsigned long flags; 115 116 if (irq > 0) { 117 spin_lock_irqsave(&lock, flags); 118 if (pcf_pending == 0) { 119 spin_unlock_irqrestore(&lock, flags); 120 prepare_to_wait(&pcf_wait, &wait, TASK_INTERRUPTIBLE); 121 if (schedule_timeout(timeout*HZ)) { 122 spin_lock_irqsave(&lock, flags); 123 if (pcf_pending == 1) { 124 pcf_pending = 0; 125 } 126 spin_unlock_irqrestore(&lock, flags); 127 } 128 finish_wait(&pcf_wait, &wait); 129 } else { 130 pcf_pending = 0; 131 spin_unlock_irqrestore(&lock, flags); 132 } 133 } else { 134 udelay(100); 135 } 136 } 137 138 139 static irqreturn_t pcf_isa_handler(int this_irq, void *dev_id, struct pt_regs *regs) { 140 spin_lock(&lock); 141 pcf_pending = 1; 142 spin_unlock(&lock); 143 wake_up_interruptible(&pcf_wait); 144 return IRQ_HANDLED; 145 } 146 147 148 static int pcf_isa_init(void) 149 { 150 spin_lock_init(&lock); 151 if (!mmapped) { 152 if (!request_region(base, 2, "i2c (isa bus adapter)")) { 153 printk(KERN_ERR 154 "i2c-elektor: requested I/O region (0x%X:2) " 155 "is in use.\n", base); 156 return -ENODEV; 157 } 158 } 159 if (irq > 0) { 160 if (request_irq(irq, pcf_isa_handler, 0, "PCF8584", NULL) < 0) { 161 printk(KERN_ERR "i2c-elektor: Request irq%d failed\n", irq); 162 irq = 0; 163 } else 164 enable_irq(irq); 165 } 166 return 0; 167 } 168 169 /* ------------------------------------------------------------------------ 170 * Encapsulate the above functions in the correct operations structure. 171 * This is only done when more than one hardware adapter is supported. 172 */ 173 static struct i2c_algo_pcf_data pcf_isa_data = { 174 .setpcf = pcf_isa_setbyte, 175 .getpcf = pcf_isa_getbyte, 176 .getown = pcf_isa_getown, 177 .getclock = pcf_isa_getclock, 178 .waitforpin = pcf_isa_waitforpin, 179 .udelay = 10, 180 .mdelay = 10, 181 .timeout = 100, 182 }; 183 184 static struct i2c_adapter pcf_isa_ops = { 185 .owner = THIS_MODULE, 186 .class = I2C_CLASS_HWMON, 187 .id = I2C_HW_P_ELEK, 188 .algo_data = &pcf_isa_data, 189 .name = "PCF8584 ISA adapter", 190 }; 191 192 static int __init i2c_pcfisa_init(void) 193 { 194 #ifdef __alpha__ 195 /* check to see we have memory mapped PCF8584 connected to the 196 Cypress cy82c693 PCI-ISA bridge as on UP2000 board */ 197 if (base == 0) { 198 struct pci_dev *cy693_dev; 199 200 cy693_dev = pci_get_device(PCI_VENDOR_ID_CONTAQ, 201 PCI_DEVICE_ID_CONTAQ_82C693, NULL); 202 if (cy693_dev) { 203 char config; 204 /* yeap, we've found cypress, let's check config */ 205 if (!pci_read_config_byte(cy693_dev, 0x47, &config)) { 206 207 pr_debug("i2c-elektor: found cy82c693, config register 0x47 = 0x%02x.\n", config); 208 209 /* UP2000 board has this register set to 0xe1, 210 but the most significant bit as seems can be 211 reset during the proper initialisation 212 sequence if guys from API decides to do that 213 (so, we can even enable Tsunami Pchip 214 window for the upper 1 Gb) */ 215 216 /* so just check for ROMCS at 0xe0000, 217 ROMCS enabled for writes 218 and external XD Bus buffer in use. */ 219 if ((config & 0x7f) == 0x61) { 220 /* seems to be UP2000 like board */ 221 base = 0xe0000; 222 /* I don't know why we need to 223 write twice */ 224 mmapped = 2; 225 /* UP2000 drives ISA with 226 8.25 MHz (PCI/4) clock 227 (this can be read from cypress) */ 228 clock = I2C_PCF_CLK | I2C_PCF_TRNS90; 229 printk(KERN_INFO "i2c-elektor: found API UP2000 like board, will probe PCF8584 later.\n"); 230 } 231 } 232 pci_dev_put(cy693_dev); 233 } 234 } 235 #endif 236 237 /* sanity checks for mmapped I/O */ 238 if (mmapped && base < 0xc8000) { 239 printk(KERN_ERR "i2c-elektor: incorrect base address (0x%0X) specified for mmapped I/O.\n", base); 240 return -ENODEV; 241 } 242 243 printk(KERN_INFO "i2c-elektor: i2c pcf8584-isa adapter driver\n"); 244 245 if (base == 0) { 246 base = DEFAULT_BASE; 247 } 248 249 init_waitqueue_head(&pcf_wait); 250 if (pcf_isa_init()) 251 return -ENODEV; 252 if (i2c_pcf_add_bus(&pcf_isa_ops) < 0) 253 goto fail; 254 255 printk(KERN_ERR "i2c-elektor: found device at %#x.\n", base); 256 257 return 0; 258 259 fail: 260 if (irq > 0) { 261 disable_irq(irq); 262 free_irq(irq, NULL); 263 } 264 265 if (!mmapped) 266 release_region(base , 2); 267 return -ENODEV; 268 } 269 270 static void i2c_pcfisa_exit(void) 271 { 272 i2c_pcf_del_bus(&pcf_isa_ops); 273 274 if (irq > 0) { 275 disable_irq(irq); 276 free_irq(irq, NULL); 277 } 278 279 if (!mmapped) 280 release_region(base , 2); 281 } 282 283 MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>"); 284 MODULE_DESCRIPTION("I2C-Bus adapter routines for PCF8584 ISA bus adapter"); 285 MODULE_LICENSE("GPL"); 286 287 module_param(base, int, 0); 288 module_param(irq, int, 0); 289 module_param(clock, int, 0); 290 module_param(own, int, 0); 291 module_param(mmapped, int, 0); 292 293 module_init(i2c_pcfisa_init); 294 module_exit(i2c_pcfisa_exit); 295