1 /* ------------------------------------------------------------------------- */
2 /* i2c-elektor.c i2c-hw access for PCF8584 style isa bus adaptes */
3 /* ------------------------------------------------------------------------- */
4 /* Copyright (C) 1995-97 Simon G. Vogl
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.
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.
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 /* ------------------------------------------------------------------------- */
22 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
23 Frodo Looijaard <frodol@dds.nl> */
25 /* Partialy rewriten by Oleg I. Vdovikin for mmapped support of
26 for Alpha Processor Inc. UP-2000(+) boards */
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/pci.h>
38 #include <linux/i2c.h>
39 #include <linux/i2c-algo-pcf.h>
40 #include <linux/i2c-elektor.h>
41 #include "i2c-pcf8584.h"
43 #define DEFAULT_BASE 0x330
47 static int clock = 0x1c;
48 static int own = 0x55;
49 static int mmapped = 0;
50 static int i2c_debug = 0;
52 /* vdovikin: removed static struct i2c_pcf_isa gpi; code -
53 this module in real supports only one device, due to missing arguments
54 in some functions, called from the algo-pcf module. Sometimes it's
55 need to be rewriten - but for now just remove this for simpler reading */
57 static wait_queue_head_t pcf_wait;
58 static int pcf_pending;
60 /* ----- global defines ----------------------------------------------- */
61 #define DEB(x) if (i2c_debug>=1) x
62 #define DEB2(x) if (i2c_debug>=2) x
63 #define DEB3(x) if (i2c_debug>=3) x
64 #define DEBE(x) x /* error messages */
66 /* ----- local functions ---------------------------------------------- */
68 static void pcf_isa_setbyte(void *data, int ctl, int val)
70 int address = ctl ? (base + 1) : base;
76 DEB3(printk(KERN_DEBUG "i2c-elektor.o: Write 0x%X 0x%02X\n", address, val & 255));
79 case 0: /* regular I/O */
82 case 2: /* double mapped I/O needed for UP2000 board,
83 I don't know why this... */
86 case 1: /* memory mapped I/O */
92 static int pcf_isa_getbyte(void *data, int ctl)
94 int address = ctl ? (base + 1) : base;
95 int val = mmapped ? readb(address) : inb(address);
97 DEB3(printk(KERN_DEBUG "i2c-elektor.o: Read 0x%X 0x%02X\n", address, val));
102 static int pcf_isa_getown(void *data)
108 static int pcf_isa_getclock(void *data)
113 static void pcf_isa_waitforpin(void) {
119 if (pcf_pending == 0) {
120 interruptible_sleep_on_timeout(&pcf_wait, timeout*HZ );
130 static void pcf_isa_handler(int this_irq, void *dev_id, struct pt_regs *regs) {
132 wake_up_interruptible(&pcf_wait);
136 static int pcf_isa_init(void)
139 if (check_region(base, 2) < 0 ) {
141 "i2c-elektor.o: requested I/O region (0x%X:2) "
142 "is in use.\n", base);
145 request_region(base, 2, "i2c (isa bus adapter)");
149 if (request_irq(irq, pcf_isa_handler, 0, "PCF8584", 0) < 0) {
150 printk(KERN_ERR "i2c-elektor.o: Request irq%d failed\n", irq);
159 static void __exit pcf_isa_exit(void)
166 release_region(base , 2);
171 static int pcf_isa_reg(struct i2c_client *client)
177 static int pcf_isa_unreg(struct i2c_client *client)
182 static void pcf_isa_inc_use(struct i2c_adapter *adap)
189 static void pcf_isa_dec_use(struct i2c_adapter *adap)
197 /* ------------------------------------------------------------------------
198 * Encapsulate the above functions in the correct operations structure.
199 * This is only done when more than one hardware adapter is supported.
201 static struct i2c_algo_pcf_data pcf_isa_data = {
202 .setpcf = pcf_isa_setbyte,
203 .getpcf = pcf_isa_getbyte,
204 .getown = pcf_isa_getown,
205 .getclock = pcf_isa_getclock,
206 .waitforpin = pcf_isa_waitforpin,
212 static struct i2c_adapter pcf_isa_ops = {
213 .name = "PCF8584 ISA adapter",
215 .algo_data = &pcf_isa_data,
216 .inc_use = pcf_isa_inc_use,
217 .dec_use = pcf_isa_dec_use,
218 .client_register = pcf_isa_reg,
219 .client_unregister = pcf_isa_unreg,
222 int __init i2c_pcfisa_init(void)
225 /* check to see we have memory mapped PCF8584 connected to the
226 Cypress cy82c693 PCI-ISA bridge as on UP2000 board */
227 if ((base == 0) && pci_present()) {
229 struct pci_dev *cy693_dev =
230 pci_find_device(PCI_VENDOR_ID_CONTAQ,
231 PCI_DEVICE_ID_CONTAQ_82C693, NULL);
235 /* yeap, we've found cypress, let's check config */
236 if (!pci_read_config_byte(cy693_dev, 0x47, &config)) {
238 DEB3(printk(KERN_DEBUG "i2c-elektor.o: found cy82c693, config register 0x47 = 0x%02x.\n", config));
240 /* UP2000 board has this register set to 0xe1,
241 but the most significant bit as seems can be
242 reset during the proper initialisation
243 sequence if guys from API decides to do that
244 (so, we can even enable Tsunami Pchip
245 window for the upper 1 Gb) */
247 /* so just check for ROMCS at 0xe0000,
248 ROMCS enabled for writes
249 and external XD Bus buffer in use. */
250 if ((config & 0x7f) == 0x61) {
251 /* seems to be UP2000 like board */
253 /* I don't know why we need to
256 /* UP2000 drives ISA with
257 8.25 MHz (PCI/4) clock
258 (this can be read from cypress) */
259 clock = I2C_PCF_CLK | I2C_PCF_TRNS90;
260 printk(KERN_INFO "i2c-elektor.o: found API UP2000 like board, will probe PCF8584 later.\n");
267 /* sanity checks for mmapped I/O */
268 if (mmapped && base < 0xc8000) {
269 printk(KERN_ERR "i2c-elektor.o: incorrect base address (0x%0X) specified for mmapped I/O.\n", base);
273 printk(KERN_INFO "i2c-elektor.o: i2c pcf8584-isa adapter module version %s (%s)\n", I2C_VERSION, I2C_DATE);
279 init_waitqueue_head(&pcf_wait);
280 if (pcf_isa_init() == 0) {
281 if (i2c_pcf_add_bus(&pcf_isa_ops) < 0)
287 printk(KERN_DEBUG "i2c-elektor.o: found device at %#x.\n", base);
296 MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
297 MODULE_DESCRIPTION("I2C-Bus adapter routines for PCF8584 ISA bus adapter");
298 MODULE_LICENSE("GPL");
300 MODULE_PARM(base, "i");
301 MODULE_PARM(irq, "i");
302 MODULE_PARM(clock, "i");
303 MODULE_PARM(own, "i");
304 MODULE_PARM(mmapped, "i");
305 MODULE_PARM(i2c_debug, "i");
307 int init_module(void)
309 return i2c_pcfisa_init();
312 void cleanup_module(void)
314 i2c_pcf_del_bus(&pcf_isa_ops);