2 * i2c-pca-isa.c driver for PCA9564 on ISA boards
3 * Copyright (C) 2004 Arcom Control Systems
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #include <linux/kernel.h>
21 #include <linux/ioport.h>
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/delay.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/wait.h>
30 #include <linux/i2c.h>
31 #include <linux/i2c-algo-pca.h>
36 #include "../algos/i2c-algo-pca.h"
43 static unsigned long base = 0x330;
46 /* Data sheet recommends 59kHz for 100kHz operation due to variation
47 * in the actual clock rate */
48 static int clock = I2C_PCA_CON_59kHz;
50 static int own = 0x55;
52 static wait_queue_head_t pca_wait;
54 static int pca_isa_getown(struct i2c_algo_pca_data *adap)
59 static int pca_isa_getclock(struct i2c_algo_pca_data *adap)
65 pca_isa_writebyte(struct i2c_algo_pca_data *adap, int reg, int val)
68 static char *names[] = { "T/O", "DAT", "ADR", "CON" };
69 printk("*** write %s at %#lx <= %#04x\n", names[reg], base+reg, val);
75 pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg)
77 int res = inb(base+reg);
80 static char *names[] = { "STA", "DAT", "ADR", "CON" };
81 printk("*** read %s => %#04x\n", names[reg], res);
87 static int pca_isa_waitforinterrupt(struct i2c_algo_pca_data *adap)
92 ret = wait_event_interruptible(pca_wait,
93 pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI);
95 while ((pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
101 static irqreturn_t pca_handler(int this_irq, void *dev_id) {
102 wake_up_interruptible(&pca_wait);
106 static struct i2c_algo_pca_data pca_isa_data = {
107 .get_own = pca_isa_getown,
108 .get_clock = pca_isa_getclock,
109 .write_byte = pca_isa_writebyte,
110 .read_byte = pca_isa_readbyte,
111 .wait_for_interrupt = pca_isa_waitforinterrupt,
114 static struct i2c_adapter pca_isa_ops = {
115 .owner = THIS_MODULE,
117 .algo_data = &pca_isa_data,
118 .name = "PCA9564 ISA Adapter",
121 static int __init pca_isa_init(void)
124 init_waitqueue_head(&pca_wait);
126 printk(KERN_INFO "i2c-pca-isa: i/o base %#08lx. irq %d\n", base, irq);
128 if (!request_region(base, IO_SIZE, "i2c-pca-isa")) {
129 printk(KERN_ERR "i2c-pca-isa: I/O address %#08lx is in use.\n", base);
134 if (request_irq(irq, pca_handler, 0, "i2c-pca-isa", &pca_isa_ops) < 0) {
135 printk(KERN_ERR "i2c-pca-isa: Request irq%d failed\n", irq);
140 if (i2c_pca_add_bus(&pca_isa_ops) < 0) {
141 printk(KERN_ERR "i2c-pca-isa: Failed to add i2c bus\n");
149 free_irq(irq, &pca_isa_ops);
151 release_region(base, IO_SIZE);
156 static void pca_isa_exit(void)
158 i2c_del_adapter(&pca_isa_ops);
162 free_irq(irq, &pca_isa_ops);
164 release_region(base, IO_SIZE);
167 MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
168 MODULE_DESCRIPTION("ISA base PCA9564 driver");
169 MODULE_LICENSE("GPL");
171 module_param(base, ulong, 0);
172 MODULE_PARM_DESC(base, "I/O base address");
174 module_param(irq, int, 0);
175 MODULE_PARM_DESC(irq, "IRQ");
176 module_param(clock, int, 0);
177 MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet");
179 module_param(own, int, 0); /* the driver can't do slave mode, so there's no real point in this */
181 module_init(pca_isa_init);
182 module_exit(pca_isa_exit);