Root/drivers/char/tb0219.c

1/*
2 * Driver for TANBAC TB0219 base board.
3 *
4 * Copyright (C) 2005 Yoichi Yuasa <yuasa@linux-mips.org>
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20#include <linux/platform_device.h>
21#include <linux/fs.h>
22#include <linux/init.h>
23#include <linux/module.h>
24
25#include <asm/io.h>
26#include <asm/reboot.h>
27#include <asm/vr41xx/giu.h>
28#include <asm/vr41xx/tb0219.h>
29
30MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
31MODULE_DESCRIPTION("TANBAC TB0219 base board driver");
32MODULE_LICENSE("GPL");
33
34static int major; /* default is dynamic major device number */
35module_param(major, int, 0);
36MODULE_PARM_DESC(major, "Major device number");
37
38static void (*old_machine_restart)(char *command);
39static void __iomem *tb0219_base;
40static DEFINE_SPINLOCK(tb0219_lock);
41
42#define tb0219_read(offset) readw(tb0219_base + (offset))
43#define tb0219_write(offset, value) writew((value), tb0219_base + (offset))
44
45#define TB0219_START 0x0a000000UL
46#define TB0219_SIZE 0x20UL
47
48#define TB0219_LED 0x00
49#define TB0219_GPIO_INPUT 0x02
50#define TB0219_GPIO_OUTPUT 0x04
51#define TB0219_DIP_SWITCH 0x06
52#define TB0219_MISC 0x08
53#define TB0219_RESET 0x0e
54#define TB0219_PCI_SLOT1_IRQ_STATUS 0x10
55#define TB0219_PCI_SLOT2_IRQ_STATUS 0x12
56#define TB0219_PCI_SLOT3_IRQ_STATUS 0x14
57
58typedef enum {
59    TYPE_LED,
60    TYPE_GPIO_OUTPUT,
61} tb0219_type_t;
62
63/*
64 * Minor device number
65 * 0 = 7 segment LED
66 *
67 * 16 = GPIO IN 0
68 * 17 = GPIO IN 1
69 * 18 = GPIO IN 2
70 * 19 = GPIO IN 3
71 * 20 = GPIO IN 4
72 * 21 = GPIO IN 5
73 * 22 = GPIO IN 6
74 * 23 = GPIO IN 7
75 *
76 * 32 = GPIO OUT 0
77 * 33 = GPIO OUT 1
78 * 34 = GPIO OUT 2
79 * 35 = GPIO OUT 3
80 * 36 = GPIO OUT 4
81 * 37 = GPIO OUT 5
82 * 38 = GPIO OUT 6
83 * 39 = GPIO OUT 7
84 *
85 * 48 = DIP switch 1
86 * 49 = DIP switch 2
87 * 50 = DIP switch 3
88 * 51 = DIP switch 4
89 * 52 = DIP switch 5
90 * 53 = DIP switch 6
91 * 54 = DIP switch 7
92 * 55 = DIP switch 8
93 */
94
95static inline char get_led(void)
96{
97    return (char)tb0219_read(TB0219_LED);
98}
99
100static inline char get_gpio_input_pin(unsigned int pin)
101{
102    uint16_t values;
103
104    values = tb0219_read(TB0219_GPIO_INPUT);
105    if (values & (1 << pin))
106        return '1';
107
108    return '0';
109}
110
111static inline char get_gpio_output_pin(unsigned int pin)
112{
113    uint16_t values;
114
115    values = tb0219_read(TB0219_GPIO_OUTPUT);
116    if (values & (1 << pin))
117        return '1';
118
119    return '0';
120}
121
122static inline char get_dip_switch(unsigned int pin)
123{
124    uint16_t values;
125
126    values = tb0219_read(TB0219_DIP_SWITCH);
127    if (values & (1 << pin))
128        return '1';
129
130    return '0';
131}
132
133static inline int set_led(char command)
134{
135    tb0219_write(TB0219_LED, command);
136
137    return 0;
138}
139
140static inline int set_gpio_output_pin(unsigned int pin, char command)
141{
142    unsigned long flags;
143    uint16_t value;
144
145    if (command != '0' && command != '1')
146        return -EINVAL;
147
148    spin_lock_irqsave(&tb0219_lock, flags);
149    value = tb0219_read(TB0219_GPIO_OUTPUT);
150    if (command == '0')
151        value &= ~(1 << pin);
152    else
153        value |= 1 << pin;
154    tb0219_write(TB0219_GPIO_OUTPUT, value);
155    spin_unlock_irqrestore(&tb0219_lock, flags);
156
157    return 0;
158
159}
160
161static ssize_t tanbac_tb0219_read(struct file *file, char __user *buf, size_t len,
162                                  loff_t *ppos)
163{
164    unsigned int minor;
165    char value;
166
167    minor = iminor(file_inode(file));
168    switch (minor) {
169    case 0:
170        value = get_led();
171        break;
172    case 16 ... 23:
173        value = get_gpio_input_pin(minor - 16);
174        break;
175    case 32 ... 39:
176        value = get_gpio_output_pin(minor - 32);
177        break;
178    case 48 ... 55:
179        value = get_dip_switch(minor - 48);
180        break;
181    default:
182        return -EBADF;
183    }
184
185    if (len <= 0)
186        return -EFAULT;
187
188    if (put_user(value, buf))
189        return -EFAULT;
190
191    return 1;
192}
193
194static ssize_t tanbac_tb0219_write(struct file *file, const char __user *data,
195                                   size_t len, loff_t *ppos)
196{
197    unsigned int minor;
198    tb0219_type_t type;
199    size_t i;
200    int retval = 0;
201    char c;
202
203    minor = iminor(file_inode(file));
204    switch (minor) {
205    case 0:
206        type = TYPE_LED;
207        break;
208    case 32 ... 39:
209        type = TYPE_GPIO_OUTPUT;
210        break;
211    default:
212        return -EBADF;
213    }
214
215    for (i = 0; i < len; i++) {
216        if (get_user(c, data + i))
217            return -EFAULT;
218
219        switch (type) {
220        case TYPE_LED:
221            retval = set_led(c);
222            break;
223        case TYPE_GPIO_OUTPUT:
224            retval = set_gpio_output_pin(minor - 32, c);
225            break;
226        }
227
228        if (retval < 0)
229            break;
230    }
231
232    return i;
233}
234
235static int tanbac_tb0219_open(struct inode *inode, struct file *file)
236{
237    unsigned int minor;
238
239    minor = iminor(inode);
240    switch (minor) {
241    case 0:
242    case 16 ... 23:
243    case 32 ... 39:
244    case 48 ... 55:
245        return nonseekable_open(inode, file);
246    default:
247        break;
248    }
249
250    return -EBADF;
251}
252
253static int tanbac_tb0219_release(struct inode *inode, struct file *file)
254{
255    return 0;
256}
257
258static const struct file_operations tb0219_fops = {
259    .owner = THIS_MODULE,
260    .read = tanbac_tb0219_read,
261    .write = tanbac_tb0219_write,
262    .open = tanbac_tb0219_open,
263    .release = tanbac_tb0219_release,
264    .llseek = no_llseek,
265};
266
267static void tb0219_restart(char *command)
268{
269    tb0219_write(TB0219_RESET, 0);
270}
271
272static void tb0219_pci_irq_init(void)
273{
274    /* PCI Slot 1 */
275    vr41xx_set_irq_trigger(TB0219_PCI_SLOT1_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
276    vr41xx_set_irq_level(TB0219_PCI_SLOT1_PIN, IRQ_LEVEL_LOW);
277
278    /* PCI Slot 2 */
279    vr41xx_set_irq_trigger(TB0219_PCI_SLOT2_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
280    vr41xx_set_irq_level(TB0219_PCI_SLOT2_PIN, IRQ_LEVEL_LOW);
281
282    /* PCI Slot 3 */
283    vr41xx_set_irq_trigger(TB0219_PCI_SLOT3_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
284    vr41xx_set_irq_level(TB0219_PCI_SLOT3_PIN, IRQ_LEVEL_LOW);
285}
286
287static int tb0219_probe(struct platform_device *dev)
288{
289    int retval;
290
291    if (request_mem_region(TB0219_START, TB0219_SIZE, "TB0219") == NULL)
292        return -EBUSY;
293
294    tb0219_base = ioremap(TB0219_START, TB0219_SIZE);
295    if (tb0219_base == NULL) {
296        release_mem_region(TB0219_START, TB0219_SIZE);
297        return -ENOMEM;
298    }
299
300    retval = register_chrdev(major, "TB0219", &tb0219_fops);
301    if (retval < 0) {
302        iounmap(tb0219_base);
303        tb0219_base = NULL;
304        release_mem_region(TB0219_START, TB0219_SIZE);
305        return retval;
306    }
307
308    old_machine_restart = _machine_restart;
309    _machine_restart = tb0219_restart;
310
311    tb0219_pci_irq_init();
312
313    if (major == 0) {
314        major = retval;
315        printk(KERN_INFO "TB0219: major number %d\n", major);
316    }
317
318    return 0;
319}
320
321static int tb0219_remove(struct platform_device *dev)
322{
323    _machine_restart = old_machine_restart;
324
325    iounmap(tb0219_base);
326    tb0219_base = NULL;
327
328    release_mem_region(TB0219_START, TB0219_SIZE);
329
330    return 0;
331}
332
333static struct platform_device *tb0219_platform_device;
334
335static struct platform_driver tb0219_device_driver = {
336    .probe = tb0219_probe,
337    .remove = tb0219_remove,
338    .driver = {
339        .name = "TB0219",
340        .owner = THIS_MODULE,
341    },
342};
343
344static int __init tanbac_tb0219_init(void)
345{
346    int retval;
347
348    tb0219_platform_device = platform_device_alloc("TB0219", -1);
349    if (!tb0219_platform_device)
350        return -ENOMEM;
351
352    retval = platform_device_add(tb0219_platform_device);
353    if (retval < 0) {
354        platform_device_put(tb0219_platform_device);
355        return retval;
356    }
357
358    retval = platform_driver_register(&tb0219_device_driver);
359    if (retval < 0)
360        platform_device_unregister(tb0219_platform_device);
361
362    return retval;
363}
364
365static void __exit tanbac_tb0219_exit(void)
366{
367    platform_driver_unregister(&tb0219_device_driver);
368    platform_device_unregister(tb0219_platform_device);
369}
370
371module_init(tanbac_tb0219_init);
372module_exit(tanbac_tb0219_exit);
373

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