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1da177e4 LT |
1 | /* |
2 | * i2c-pca-isa.c driver for PCA9564 on ISA boards | |
3 | * Copyright (C) 2004 Arcom Control Systems | |
4 | * | |
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. | |
9 | * | |
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. | |
14 | * | |
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. | |
18 | */ | |
19 | ||
1da177e4 LT |
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> | |
1da177e4 LT |
28 | #include <linux/wait.h> |
29 | ||
5cedb05d | 30 | #include <linux/isa.h> |
1da177e4 LT |
31 | #include <linux/i2c.h> |
32 | #include <linux/i2c-algo-pca.h> | |
33 | ||
34 | #include <asm/io.h> | |
35 | #include <asm/irq.h> | |
36 | ||
37 | #include "../algos/i2c-algo-pca.h" | |
38 | ||
39 | #define IO_SIZE 4 | |
40 | ||
41 | #undef DEBUG_IO | |
42 | //#define DEBUG_IO | |
43 | ||
44 | static unsigned long base = 0x330; | |
45 | static int irq = 10; | |
46 | ||
47 | /* Data sheet recommends 59kHz for 100kHz operation due to variation | |
48 | * in the actual clock rate */ | |
49 | static int clock = I2C_PCA_CON_59kHz; | |
50 | ||
51 | static int own = 0x55; | |
52 | ||
53 | static wait_queue_head_t pca_wait; | |
54 | ||
55 | static int pca_isa_getown(struct i2c_algo_pca_data *adap) | |
56 | { | |
57 | return (own); | |
58 | } | |
59 | ||
60 | static int pca_isa_getclock(struct i2c_algo_pca_data *adap) | |
61 | { | |
62 | return (clock); | |
63 | } | |
64 | ||
65 | static void | |
66 | pca_isa_writebyte(struct i2c_algo_pca_data *adap, int reg, int val) | |
67 | { | |
68 | #ifdef DEBUG_IO | |
69 | static char *names[] = { "T/O", "DAT", "ADR", "CON" }; | |
70 | printk("*** write %s at %#lx <= %#04x\n", names[reg], base+reg, val); | |
71 | #endif | |
72 | outb(val, base+reg); | |
73 | } | |
74 | ||
75 | static int | |
76 | pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg) | |
77 | { | |
78 | int res = inb(base+reg); | |
79 | #ifdef DEBUG_IO | |
80 | { | |
3d438291 | 81 | static char *names[] = { "STA", "DAT", "ADR", "CON" }; |
1da177e4 LT |
82 | printk("*** read %s => %#04x\n", names[reg], res); |
83 | } | |
84 | #endif | |
85 | return res; | |
86 | } | |
87 | ||
88 | static int pca_isa_waitforinterrupt(struct i2c_algo_pca_data *adap) | |
89 | { | |
90 | int ret = 0; | |
91 | ||
92 | if (irq > -1) { | |
93 | ret = wait_event_interruptible(pca_wait, | |
94 | pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI); | |
95 | } else { | |
3d438291 | 96 | while ((pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0) |
1da177e4 LT |
97 | udelay(100); |
98 | } | |
99 | return ret; | |
100 | } | |
101 | ||
7d12e780 | 102 | static irqreturn_t pca_handler(int this_irq, void *dev_id) { |
1da177e4 LT |
103 | wake_up_interruptible(&pca_wait); |
104 | return IRQ_HANDLED; | |
105 | } | |
106 | ||
107 | static struct i2c_algo_pca_data pca_isa_data = { | |
108 | .get_own = pca_isa_getown, | |
109 | .get_clock = pca_isa_getclock, | |
110 | .write_byte = pca_isa_writebyte, | |
111 | .read_byte = pca_isa_readbyte, | |
112 | .wait_for_interrupt = pca_isa_waitforinterrupt, | |
113 | }; | |
114 | ||
115 | static struct i2c_adapter pca_isa_ops = { | |
116 | .owner = THIS_MODULE, | |
117 | .id = I2C_HW_A_ISA, | |
118 | .algo_data = &pca_isa_data, | |
119 | .name = "PCA9564 ISA Adapter", | |
120 | }; | |
121 | ||
5cedb05d | 122 | static int __devinit pca_isa_probe(struct device *dev, unsigned int id) |
1da177e4 | 123 | { |
1da177e4 LT |
124 | init_waitqueue_head(&pca_wait); |
125 | ||
5cedb05d | 126 | dev_info(dev, "i/o base %#08lx. irq %d\n", base, irq); |
1da177e4 | 127 | |
104cb574 CK |
128 | #ifdef CONFIG_PPC_MERGE |
129 | if (check_legacy_ioport(base)) { | |
130 | dev_err(dev, "I/O address %#08lx is not available\n", base); | |
131 | goto out; | |
132 | } | |
133 | #endif | |
134 | ||
1da177e4 | 135 | if (!request_region(base, IO_SIZE, "i2c-pca-isa")) { |
5cedb05d | 136 | dev_err(dev, "I/O address %#08lx is in use\n", base); |
1da177e4 LT |
137 | goto out; |
138 | } | |
139 | ||
140 | if (irq > -1) { | |
141 | if (request_irq(irq, pca_handler, 0, "i2c-pca-isa", &pca_isa_ops) < 0) { | |
5cedb05d | 142 | dev_err(dev, "Request irq%d failed\n", irq); |
1da177e4 LT |
143 | goto out_region; |
144 | } | |
145 | } | |
146 | ||
147 | if (i2c_pca_add_bus(&pca_isa_ops) < 0) { | |
5cedb05d | 148 | dev_err(dev, "Failed to add i2c bus\n"); |
1da177e4 LT |
149 | goto out_irq; |
150 | } | |
151 | ||
152 | return 0; | |
153 | ||
154 | out_irq: | |
155 | if (irq > -1) | |
156 | free_irq(irq, &pca_isa_ops); | |
157 | out_region: | |
158 | release_region(base, IO_SIZE); | |
159 | out: | |
160 | return -ENODEV; | |
161 | } | |
162 | ||
5cedb05d | 163 | static int __devexit pca_isa_remove(struct device *dev, unsigned int id) |
1da177e4 | 164 | { |
3269711b | 165 | i2c_del_adapter(&pca_isa_ops); |
1da177e4 LT |
166 | |
167 | if (irq > 0) { | |
168 | disable_irq(irq); | |
169 | free_irq(irq, &pca_isa_ops); | |
170 | } | |
171 | release_region(base, IO_SIZE); | |
5cedb05d JD |
172 | |
173 | return 0; | |
174 | } | |
175 | ||
176 | static struct isa_driver pca_isa_driver = { | |
177 | .probe = pca_isa_probe, | |
178 | .remove = __devexit_p(pca_isa_remove), | |
179 | .driver = { | |
180 | .owner = THIS_MODULE, | |
181 | .name = "i2c-pca-isa", | |
182 | } | |
183 | }; | |
184 | ||
185 | static int __init pca_isa_init(void) | |
186 | { | |
187 | return isa_register_driver(&pca_isa_driver, 1); | |
188 | } | |
189 | ||
190 | static void __exit pca_isa_exit(void) | |
191 | { | |
192 | isa_unregister_driver(&pca_isa_driver); | |
1da177e4 LT |
193 | } |
194 | ||
195 | MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>"); | |
196 | MODULE_DESCRIPTION("ISA base PCA9564 driver"); | |
197 | MODULE_LICENSE("GPL"); | |
198 | ||
199 | module_param(base, ulong, 0); | |
200 | MODULE_PARM_DESC(base, "I/O base address"); | |
201 | ||
202 | module_param(irq, int, 0); | |
203 | MODULE_PARM_DESC(irq, "IRQ"); | |
204 | module_param(clock, int, 0); | |
205 | MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet"); | |
206 | ||
207 | module_param(own, int, 0); /* the driver can't do slave mode, so there's no real point in this */ | |
208 | ||
209 | module_init(pca_isa_init); | |
210 | module_exit(pca_isa_exit); |