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/config.h>
29 #include <linux/kernel.h>
30 #include <linux/ioport.h>
31 #include <linux/module.h>
32 #include <linux/delay.h>
33 #include <linux/slab.h>
34 #include <linux/init.h>
35 #include <linux/interrupt.h>
36 #include <linux/pci.h>
37 #include <linux/wait.h>
39 #include <linux/i2c.h>
40 #include <linux/i2c-algo-pcf.h>
45 #include "../algos/i2c-algo-pcf.h"
47 #define DEFAULT_BASE 0x330
51 static int clock = 0x1c;
52 static int own = 0x55;
55 /* vdovikin: removed static struct i2c_pcf_isa gpi; code -
56 this module in real supports only one device, due to missing arguments
57 in some functions, called from the algo-pcf module. Sometimes it's
58 need to be rewriten - but for now just remove this for simpler reading */
60 static wait_queue_head_t pcf_wait;
61 static int pcf_pending;
62 static spinlock_t lock;
64 /* ----- local functions ---------------------------------------------- */
66 static void pcf_isa_setbyte(void *data, int ctl, int val)
68 int address = ctl ? (base + 1) : base;
70 /* enable irq if any specified for serial operation */
71 if (ctl && irq && (val & I2C_PCF_ESO)) {
75 pr_debug("i2c-elektor: Write 0x%X 0x%02X\n", address, val & 255);
78 case 0: /* regular I/O */
81 case 2: /* double mapped I/O needed for UP2000 board,
82 I don't know why this... */
83 writeb(val, (void *)address);
85 case 1: /* memory mapped I/O */
86 writeb(val, (void *)address);
91 static int pcf_isa_getbyte(void *data, int ctl)
93 int address = ctl ? (base + 1) : base;
94 int val = mmapped ? readb((void *)address) : inb(address);
96 pr_debug("i2c-elektor: Read 0x%X 0x%02X\n", address, val);
101 static int pcf_isa_getown(void *data)
107 static int pcf_isa_getclock(void *data)
112 static void pcf_isa_waitforpin(void) {
118 spin_lock_irqsave(&lock, flags);
119 if (pcf_pending == 0) {
120 spin_unlock_irqrestore(&lock, flags);
121 if (interruptible_sleep_on_timeout(&pcf_wait,
123 spin_lock_irqsave(&lock, flags);
124 if (pcf_pending == 1) {
127 spin_unlock_irqrestore(&lock, flags);
131 spin_unlock_irqrestore(&lock, flags);
139 static irqreturn_t pcf_isa_handler(int this_irq, void *dev_id, struct pt_regs *regs) {
143 wake_up_interruptible(&pcf_wait);
148 static int pcf_isa_init(void)
150 spin_lock_init(&lock);
152 if (!request_region(base, 2, "i2c (isa bus adapter)")) {
154 "i2c-elektor: requested I/O region (0x%X:2) "
155 "is in use.\n", base);
160 if (request_irq(irq, pcf_isa_handler, 0, "PCF8584", NULL) < 0) {
161 printk(KERN_ERR "i2c-elektor: Request irq%d failed\n", irq);
169 /* ------------------------------------------------------------------------
170 * Encapsulate the above functions in the correct operations structure.
171 * This is only done when more than one hardware adapter is supported.
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,
184 static struct i2c_adapter pcf_isa_ops = {
185 .owner = THIS_MODULE,
187 .algo_data = &pcf_isa_data,
188 .name = "PCF8584 ISA adapter",
191 static int __init i2c_pcfisa_init(void)
194 /* check to see we have memory mapped PCF8584 connected to the
195 Cypress cy82c693 PCI-ISA bridge as on UP2000 board */
197 struct pci_dev *cy693_dev;
199 cy693_dev = pci_get_device(PCI_VENDOR_ID_CONTAQ,
200 PCI_DEVICE_ID_CONTAQ_82C693, NULL);
203 /* yeap, we've found cypress, let's check config */
204 if (!pci_read_config_byte(cy693_dev, 0x47, &config)) {
206 pr_debug("i2c-elektor: found cy82c693, config register 0x47 = 0x%02x.\n", config);
208 /* UP2000 board has this register set to 0xe1,
209 but the most significant bit as seems can be
210 reset during the proper initialisation
211 sequence if guys from API decides to do that
212 (so, we can even enable Tsunami Pchip
213 window for the upper 1 Gb) */
215 /* so just check for ROMCS at 0xe0000,
216 ROMCS enabled for writes
217 and external XD Bus buffer in use. */
218 if ((config & 0x7f) == 0x61) {
219 /* seems to be UP2000 like board */
221 /* I don't know why we need to
224 /* UP2000 drives ISA with
225 8.25 MHz (PCI/4) clock
226 (this can be read from cypress) */
227 clock = I2C_PCF_CLK | I2C_PCF_TRNS90;
228 printk(KERN_INFO "i2c-elektor: found API UP2000 like board, will probe PCF8584 later.\n");
231 pci_dev_put(cy693_dev);
236 /* sanity checks for mmapped I/O */
237 if (mmapped && base < 0xc8000) {
238 printk(KERN_ERR "i2c-elektor: incorrect base address (0x%0X) specified for mmapped I/O.\n", base);
242 printk(KERN_INFO "i2c-elektor: i2c pcf8584-isa adapter driver\n");
248 init_waitqueue_head(&pcf_wait);
251 if (i2c_pcf_add_bus(&pcf_isa_ops) < 0)
254 printk(KERN_ERR "i2c-elektor: found device at %#x.\n", base);
265 release_region(base , 2);
269 static void i2c_pcfisa_exit(void)
271 i2c_pcf_del_bus(&pcf_isa_ops);
279 release_region(base , 2);
282 MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
283 MODULE_DESCRIPTION("I2C-Bus adapter routines for PCF8584 ISA bus adapter");
284 MODULE_LICENSE("GPL");
286 module_param(base, int, 0);
287 module_param(irq, int, 0);
288 module_param(clock, int, 0);
289 module_param(own, int, 0);
290 module_param(mmapped, int, 0);
292 module_init(i2c_pcfisa_init);
293 module_exit(i2c_pcfisa_exit);