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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 | |
c01b0831 | 4 | * Copyright (C) 2008 Pengutronix |
1da177e4 LT |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | */ | |
20 | ||
1da177e4 LT |
21 | #include <linux/kernel.h> |
22 | #include <linux/ioport.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/moduleparam.h> | |
25 | #include <linux/delay.h> | |
1da177e4 LT |
26 | #include <linux/init.h> |
27 | #include <linux/interrupt.h> | |
1da177e4 | 28 | #include <linux/wait.h> |
5cedb05d | 29 | #include <linux/isa.h> |
1da177e4 LT |
30 | #include <linux/i2c.h> |
31 | #include <linux/i2c-algo-pca.h> | |
32 | ||
33 | #include <asm/io.h> | |
34 | #include <asm/irq.h> | |
35 | ||
c01b0831 | 36 | #define DRIVER "i2c-pca-isa" |
1da177e4 LT |
37 | #define IO_SIZE 4 |
38 | ||
ce564033 RH |
39 | static unsigned long base; |
40 | static int irq = -1; | |
1da177e4 LT |
41 | |
42 | /* Data sheet recommends 59kHz for 100kHz operation due to variation | |
43 | * in the actual clock rate */ | |
44 | static int clock = I2C_PCA_CON_59kHz; | |
45 | ||
1da177e4 LT |
46 | static wait_queue_head_t pca_wait; |
47 | ||
c01b0831 | 48 | static void pca_isa_writebyte(void *pd, int reg, int val) |
1da177e4 LT |
49 | { |
50 | #ifdef DEBUG_IO | |
51 | static char *names[] = { "T/O", "DAT", "ADR", "CON" }; | |
154d22b0 FS |
52 | printk(KERN_DEBUG "*** write %s at %#lx <= %#04x\n", names[reg], |
53 | base+reg, val); | |
1da177e4 LT |
54 | #endif |
55 | outb(val, base+reg); | |
56 | } | |
57 | ||
c01b0831 | 58 | static int pca_isa_readbyte(void *pd, int reg) |
1da177e4 LT |
59 | { |
60 | int res = inb(base+reg); | |
61 | #ifdef DEBUG_IO | |
62 | { | |
3d438291 | 63 | static char *names[] = { "STA", "DAT", "ADR", "CON" }; |
154d22b0 | 64 | printk(KERN_DEBUG "*** read %s => %#04x\n", names[reg], res); |
1da177e4 LT |
65 | } |
66 | #endif | |
67 | return res; | |
68 | } | |
69 | ||
c01b0831 | 70 | static int pca_isa_waitforcompletion(void *pd) |
1da177e4 LT |
71 | { |
72 | int ret = 0; | |
73 | ||
74 | if (irq > -1) { | |
75 | ret = wait_event_interruptible(pca_wait, | |
c01b0831 | 76 | pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI); |
1da177e4 | 77 | } else { |
c01b0831 | 78 | while ((pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0) |
1da177e4 LT |
79 | udelay(100); |
80 | } | |
81 | return ret; | |
82 | } | |
83 | ||
c01b0831 WS |
84 | static void pca_isa_resetchip(void *pd) |
85 | { | |
86 | /* apparently only an external reset will do it. not a lot can be done */ | |
87 | printk(KERN_WARNING DRIVER ": Haven't figured out how to do a reset yet\n"); | |
88 | } | |
89 | ||
7d12e780 | 90 | static irqreturn_t pca_handler(int this_irq, void *dev_id) { |
1da177e4 LT |
91 | wake_up_interruptible(&pca_wait); |
92 | return IRQ_HANDLED; | |
93 | } | |
94 | ||
95 | static struct i2c_algo_pca_data pca_isa_data = { | |
c01b0831 | 96 | /* .data intentionally left NULL, not needed with ISA */ |
1da177e4 LT |
97 | .write_byte = pca_isa_writebyte, |
98 | .read_byte = pca_isa_readbyte, | |
c01b0831 WS |
99 | .wait_for_completion = pca_isa_waitforcompletion, |
100 | .reset_chip = pca_isa_resetchip, | |
1da177e4 LT |
101 | }; |
102 | ||
103 | static struct i2c_adapter pca_isa_ops = { | |
104 | .owner = THIS_MODULE, | |
1da177e4 LT |
105 | .algo_data = &pca_isa_data, |
106 | .name = "PCA9564 ISA Adapter", | |
c01b0831 | 107 | .timeout = 100, |
1da177e4 LT |
108 | }; |
109 | ||
ce564033 RH |
110 | static int __devinit pca_isa_match(struct device *dev, unsigned int id) |
111 | { | |
112 | int match = base != 0; | |
113 | ||
114 | if (match) { | |
115 | if (irq <= -1) | |
116 | dev_warn(dev, "Using polling mode (specify irq)\n"); | |
117 | } else | |
118 | dev_err(dev, "Please specify I/O base\n"); | |
119 | ||
120 | return match; | |
121 | } | |
122 | ||
5cedb05d | 123 | static int __devinit pca_isa_probe(struct device *dev, unsigned int id) |
1da177e4 | 124 | { |
1da177e4 LT |
125 | init_waitqueue_head(&pca_wait); |
126 | ||
5cedb05d | 127 | dev_info(dev, "i/o base %#08lx. irq %d\n", base, irq); |
1da177e4 | 128 | |
68e1ee62 | 129 | #ifdef CONFIG_PPC |
104cb574 CK |
130 | if (check_legacy_ioport(base)) { |
131 | dev_err(dev, "I/O address %#08lx is not available\n", base); | |
132 | goto out; | |
133 | } | |
134 | #endif | |
135 | ||
1da177e4 | 136 | if (!request_region(base, IO_SIZE, "i2c-pca-isa")) { |
5cedb05d | 137 | dev_err(dev, "I/O address %#08lx is in use\n", base); |
1da177e4 LT |
138 | goto out; |
139 | } | |
140 | ||
141 | if (irq > -1) { | |
142 | if (request_irq(irq, pca_handler, 0, "i2c-pca-isa", &pca_isa_ops) < 0) { | |
5cedb05d | 143 | dev_err(dev, "Request irq%d failed\n", irq); |
1da177e4 LT |
144 | goto out_region; |
145 | } | |
146 | } | |
147 | ||
c01b0831 | 148 | pca_isa_data.i2c_clock = clock; |
1da177e4 | 149 | if (i2c_pca_add_bus(&pca_isa_ops) < 0) { |
5cedb05d | 150 | dev_err(dev, "Failed to add i2c bus\n"); |
1da177e4 LT |
151 | goto out_irq; |
152 | } | |
153 | ||
154 | return 0; | |
155 | ||
156 | out_irq: | |
157 | if (irq > -1) | |
158 | free_irq(irq, &pca_isa_ops); | |
159 | out_region: | |
160 | release_region(base, IO_SIZE); | |
161 | out: | |
162 | return -ENODEV; | |
163 | } | |
164 | ||
5cedb05d | 165 | static int __devexit pca_isa_remove(struct device *dev, unsigned int id) |
1da177e4 | 166 | { |
3269711b | 167 | i2c_del_adapter(&pca_isa_ops); |
1da177e4 | 168 | |
ce564033 | 169 | if (irq > -1) { |
1da177e4 LT |
170 | disable_irq(irq); |
171 | free_irq(irq, &pca_isa_ops); | |
172 | } | |
173 | release_region(base, IO_SIZE); | |
5cedb05d JD |
174 | |
175 | return 0; | |
176 | } | |
177 | ||
178 | static struct isa_driver pca_isa_driver = { | |
ce564033 | 179 | .match = pca_isa_match, |
5cedb05d JD |
180 | .probe = pca_isa_probe, |
181 | .remove = __devexit_p(pca_isa_remove), | |
182 | .driver = { | |
183 | .owner = THIS_MODULE, | |
c01b0831 | 184 | .name = DRIVER, |
5cedb05d JD |
185 | } |
186 | }; | |
187 | ||
188 | static int __init pca_isa_init(void) | |
189 | { | |
190 | return isa_register_driver(&pca_isa_driver, 1); | |
191 | } | |
192 | ||
193 | static void __exit pca_isa_exit(void) | |
194 | { | |
195 | isa_unregister_driver(&pca_isa_driver); | |
1da177e4 LT |
196 | } |
197 | ||
198 | MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>"); | |
199 | MODULE_DESCRIPTION("ISA base PCA9564 driver"); | |
200 | MODULE_LICENSE("GPL"); | |
201 | ||
202 | module_param(base, ulong, 0); | |
203 | MODULE_PARM_DESC(base, "I/O base address"); | |
204 | ||
205 | module_param(irq, int, 0); | |
206 | MODULE_PARM_DESC(irq, "IRQ"); | |
207 | module_param(clock, int, 0); | |
208 | MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet"); | |
209 | ||
1da177e4 LT |
210 | module_init(pca_isa_init); |
211 | module_exit(pca_isa_exit); |