Merge tag 'v3.14.25' into backport/v3.14.24-ltsi-rc1+v3.14.25/snapshot-merge.wip
[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / i2c / busses / i2c-pca-isa.c
1 /*
2  *  i2c-pca-isa.c driver for PCA9564 on ISA boards
3  *    Copyright (C) 2004 Arcom Control Systems
4  *    Copyright (C) 2008 Pengutronix
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
17 #include <linux/kernel.h>
18 #include <linux/ioport.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/delay.h>
22 #include <linux/jiffies.h>
23 #include <linux/init.h>
24 #include <linux/interrupt.h>
25 #include <linux/wait.h>
26 #include <linux/isa.h>
27 #include <linux/i2c.h>
28 #include <linux/i2c-algo-pca.h>
29 #include <linux/io.h>
30
31 #include <asm/irq.h>
32
33 #define DRIVER "i2c-pca-isa"
34 #define IO_SIZE 4
35
36 static unsigned long base;
37 static int irq = -1;
38
39 /* Data sheet recommends 59kHz for 100kHz operation due to variation
40  * in the actual clock rate */
41 static int clock  = 59000;
42
43 static struct i2c_adapter pca_isa_ops;
44 static wait_queue_head_t pca_wait;
45
46 static void pca_isa_writebyte(void *pd, int reg, int val)
47 {
48 #ifdef DEBUG_IO
49         static char *names[] = { "T/O", "DAT", "ADR", "CON" };
50         printk(KERN_DEBUG "*** write %s at %#lx <= %#04x\n", names[reg],
51                base+reg, val);
52 #endif
53         outb(val, base+reg);
54 }
55
56 static int pca_isa_readbyte(void *pd, int reg)
57 {
58         int res = inb(base+reg);
59 #ifdef DEBUG_IO
60         {
61                 static char *names[] = { "STA", "DAT", "ADR", "CON" };
62                 printk(KERN_DEBUG "*** read  %s => %#04x\n", names[reg], res);
63         }
64 #endif
65         return res;
66 }
67
68 static int pca_isa_waitforcompletion(void *pd)
69 {
70         unsigned long timeout;
71         long ret;
72
73         if (irq > -1) {
74                 ret = wait_event_timeout(pca_wait,
75                                 pca_isa_readbyte(pd, I2C_PCA_CON)
76                                 & I2C_PCA_CON_SI, pca_isa_ops.timeout);
77         } else {
78                 /* Do polling */
79                 timeout = jiffies + pca_isa_ops.timeout;
80                 do {
81                         ret = time_before(jiffies, timeout);
82                         if (pca_isa_readbyte(pd, I2C_PCA_CON)
83                                         & I2C_PCA_CON_SI)
84                                 break;
85                         udelay(100);
86                 } while (ret);
87         }
88
89         return ret > 0;
90 }
91
92 static void pca_isa_resetchip(void *pd)
93 {
94         /* apparently only an external reset will do it. not a lot can be done */
95         printk(KERN_WARNING DRIVER ": Haven't figured out how to do a reset yet\n");
96 }
97
98 static irqreturn_t pca_handler(int this_irq, void *dev_id) {
99         wake_up(&pca_wait);
100         return IRQ_HANDLED;
101 }
102
103 static struct i2c_algo_pca_data pca_isa_data = {
104         /* .data intentionally left NULL, not needed with ISA */
105         .write_byte             = pca_isa_writebyte,
106         .read_byte              = pca_isa_readbyte,
107         .wait_for_completion    = pca_isa_waitforcompletion,
108         .reset_chip             = pca_isa_resetchip,
109 };
110
111 static struct i2c_adapter pca_isa_ops = {
112         .owner          = THIS_MODULE,
113         .algo_data      = &pca_isa_data,
114         .name           = "PCA9564/PCA9665 ISA Adapter",
115         .timeout        = HZ,
116 };
117
118 static int pca_isa_match(struct device *dev, unsigned int id)
119 {
120         int match = base != 0;
121
122         if (match) {
123                 if (irq <= -1)
124                         dev_warn(dev, "Using polling mode (specify irq)\n");
125         } else
126                 dev_err(dev, "Please specify I/O base\n");
127
128         return match;
129 }
130
131 static int pca_isa_probe(struct device *dev, unsigned int id)
132 {
133         init_waitqueue_head(&pca_wait);
134
135         dev_info(dev, "i/o base %#08lx. irq %d\n", base, irq);
136
137 #ifdef CONFIG_PPC
138         if (check_legacy_ioport(base)) {
139                 dev_err(dev, "I/O address %#08lx is not available\n", base);
140                 goto out;
141         }
142 #endif
143
144         if (!request_region(base, IO_SIZE, "i2c-pca-isa")) {
145                 dev_err(dev, "I/O address %#08lx is in use\n", base);
146                 goto out;
147         }
148
149         if (irq > -1) {
150                 if (request_irq(irq, pca_handler, 0, "i2c-pca-isa", &pca_isa_ops) < 0) {
151                         dev_err(dev, "Request irq%d failed\n", irq);
152                         goto out_region;
153                 }
154         }
155
156         pca_isa_data.i2c_clock = clock;
157         if (i2c_pca_add_bus(&pca_isa_ops) < 0) {
158                 dev_err(dev, "Failed to add i2c bus\n");
159                 goto out_irq;
160         }
161
162         return 0;
163
164  out_irq:
165         if (irq > -1)
166                 free_irq(irq, &pca_isa_ops);
167  out_region:
168         release_region(base, IO_SIZE);
169  out:
170         return -ENODEV;
171 }
172
173 static int pca_isa_remove(struct device *dev, unsigned int id)
174 {
175         i2c_del_adapter(&pca_isa_ops);
176
177         if (irq > -1) {
178                 disable_irq(irq);
179                 free_irq(irq, &pca_isa_ops);
180         }
181         release_region(base, IO_SIZE);
182
183         return 0;
184 }
185
186 static struct isa_driver pca_isa_driver = {
187         .match          = pca_isa_match,
188         .probe          = pca_isa_probe,
189         .remove         = pca_isa_remove,
190         .driver = {
191                 .owner  = THIS_MODULE,
192                 .name   = DRIVER,
193         }
194 };
195
196 static int __init pca_isa_init(void)
197 {
198         return isa_register_driver(&pca_isa_driver, 1);
199 }
200
201 static void __exit pca_isa_exit(void)
202 {
203         isa_unregister_driver(&pca_isa_driver);
204 }
205
206 MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
207 MODULE_DESCRIPTION("ISA base PCA9564/PCA9665 driver");
208 MODULE_LICENSE("GPL");
209
210 module_param(base, ulong, 0);
211 MODULE_PARM_DESC(base, "I/O base address");
212
213 module_param(irq, int, 0);
214 MODULE_PARM_DESC(irq, "IRQ");
215 module_param(clock, int, 0);
216 MODULE_PARM_DESC(clock, "Clock rate in hertz.\n\t\t"
217                 "For PCA9564: 330000,288000,217000,146000,"
218                 "88000,59000,44000,36000\n"
219                 "\t\tFor PCA9665:\tStandard: 60300 - 100099\n"
220                 "\t\t\t\tFast: 100100 - 400099\n"
221                 "\t\t\t\tFast+: 400100 - 10000099\n"
222                 "\t\t\t\tTurbo: Up to 1265800");
223
224 module_init(pca_isa_init);
225 module_exit(pca_isa_exit);