1 /* ------------------------------------------------------------------------- */
2 /* i2c-elektor.c i2c-hw access for PCF8584 style isa bus adaptes */
3 /* ------------------------------------------------------------------------- */
4 /* Copyright (C) 1995-97 Simon G. Vogl
5 1998-99 Hans Berglund
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
20 /* ------------------------------------------------------------------------- */
21
22 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
23 Frodo Looijaard <frodol@dds.nl> */
24
25 /* Partially rewriten by Oleg I. Vdovikin for mmapped support of
26 for Alpha Processor Inc. UP-2000(+) boards */
27
28 #include <linux/kernel.h>
29 #include <linux/ioport.h>
30 #include <linux/module.h>
31 #include <linux/delay.h>
32 #include <linux/init.h>
33 #include <linux/interrupt.h>
34 #include <linux/pci.h>
35 #include <linux/wait.h>
36
37 #include <linux/isa.h>
38 #include <linux/i2c.h>
39 #include <linux/i2c-algo-pcf.h>
40 #include <linux/io.h>
41
42 #include <asm/irq.h>
43
44 #include "../algos/i2c-algo-pcf.h"
45
46 #define DEFAULT_BASE 0x330
47
48 static int base;
49 static u8 __iomem *base_iomem;
50
51 static int irq;
52 static int clock = 0x1c;
53 static int own = 0x55;
54 static int mmapped;
55
56 /* vdovikin: removed static struct i2c_pcf_isa gpi; code -
57 this module in real supports only one device, due to missing arguments
58 in some functions, called from the algo-pcf module. Sometimes it's
59 need to be rewriten - but for now just remove this for simpler reading */
60
61 static wait_queue_head_t pcf_wait;
62 static int pcf_pending;
63 static spinlock_t lock;
64
65 static struct i2c_adapter pcf_isa_ops;
66
67 /* ----- local functions ---------------------------------------------- */
68
pcf_isa_setbyte(void * data,int ctl,int val)69 static void pcf_isa_setbyte(void *data, int ctl, int val)
70 {
71 u8 __iomem *address = ctl ? (base_iomem + 1) : base_iomem;
72
73 /* enable irq if any specified for serial operation */
74 if (ctl && irq && (val & I2C_PCF_ESO)) {
75 val |= I2C_PCF_ENI;
76 }
77
78 pr_debug("%s: Write %p 0x%02X\n", pcf_isa_ops.name, address, val);
79 iowrite8(val, address);
80 #ifdef __alpha__
81 /* API UP2000 needs some hardware fudging to make the write stick */
82 iowrite8(val, address);
83 #endif
84 }
85
pcf_isa_getbyte(void * data,int ctl)86 static int pcf_isa_getbyte(void *data, int ctl)
87 {
88 u8 __iomem *address = ctl ? (base_iomem + 1) : base_iomem;
89 int val = ioread8(address);
90
91 pr_debug("%s: Read %p 0x%02X\n", pcf_isa_ops.name, address, val);
92 return (val);
93 }
94
pcf_isa_getown(void * data)95 static int pcf_isa_getown(void *data)
96 {
97 return (own);
98 }
99
100
pcf_isa_getclock(void * data)101 static int pcf_isa_getclock(void *data)
102 {
103 return (clock);
104 }
105
pcf_isa_waitforpin(void * data)106 static void pcf_isa_waitforpin(void *data)
107 {
108 DEFINE_WAIT(wait);
109 int timeout = 2;
110 unsigned long flags;
111
112 if (irq > 0) {
113 spin_lock_irqsave(&lock, flags);
114 if (pcf_pending == 0) {
115 spin_unlock_irqrestore(&lock, flags);
116 prepare_to_wait(&pcf_wait, &wait, TASK_INTERRUPTIBLE);
117 if (schedule_timeout(timeout*HZ)) {
118 spin_lock_irqsave(&lock, flags);
119 if (pcf_pending == 1) {
120 pcf_pending = 0;
121 }
122 spin_unlock_irqrestore(&lock, flags);
123 }
124 finish_wait(&pcf_wait, &wait);
125 } else {
126 pcf_pending = 0;
127 spin_unlock_irqrestore(&lock, flags);
128 }
129 } else {
130 udelay(100);
131 }
132 }
133
134
pcf_isa_handler(int this_irq,void * dev_id)135 static irqreturn_t pcf_isa_handler(int this_irq, void *dev_id) {
136 spin_lock(&lock);
137 pcf_pending = 1;
138 spin_unlock(&lock);
139 wake_up_interruptible(&pcf_wait);
140 return IRQ_HANDLED;
141 }
142
143
pcf_isa_init(void)144 static int pcf_isa_init(void)
145 {
146 spin_lock_init(&lock);
147 if (!mmapped) {
148 if (!request_region(base, 2, pcf_isa_ops.name)) {
149 printk(KERN_ERR "%s: requested I/O region (%#x:2) is "
150 "in use\n", pcf_isa_ops.name, base);
151 return -ENODEV;
152 }
153 base_iomem = ioport_map(base, 2);
154 if (!base_iomem) {
155 printk(KERN_ERR "%s: remap of I/O region %#x failed\n",
156 pcf_isa_ops.name, base);
157 release_region(base, 2);
158 return -ENODEV;
159 }
160 } else {
161 if (!request_mem_region(base, 2, pcf_isa_ops.name)) {
162 printk(KERN_ERR "%s: requested memory region (%#x:2) "
163 "is in use\n", pcf_isa_ops.name, base);
164 return -ENODEV;
165 }
166 base_iomem = ioremap(base, 2);
167 if (base_iomem == NULL) {
168 printk(KERN_ERR "%s: remap of memory region %#x "
169 "failed\n", pcf_isa_ops.name, base);
170 release_mem_region(base, 2);
171 return -ENODEV;
172 }
173 }
174 pr_debug("%s: registers %#x remapped to %p\n", pcf_isa_ops.name, base,
175 base_iomem);
176
177 if (irq > 0) {
178 if (request_irq(irq, pcf_isa_handler, 0, pcf_isa_ops.name,
179 NULL) < 0) {
180 printk(KERN_ERR "%s: Request irq%d failed\n",
181 pcf_isa_ops.name, irq);
182 irq = 0;
183 } else
184 enable_irq(irq);
185 }
186 return 0;
187 }
188
189 /* ------------------------------------------------------------------------
190 * Encapsulate the above functions in the correct operations structure.
191 * This is only done when more than one hardware adapter is supported.
192 */
193 static struct i2c_algo_pcf_data pcf_isa_data = {
194 .setpcf = pcf_isa_setbyte,
195 .getpcf = pcf_isa_getbyte,
196 .getown = pcf_isa_getown,
197 .getclock = pcf_isa_getclock,
198 .waitforpin = pcf_isa_waitforpin,
199 };
200
201 static struct i2c_adapter pcf_isa_ops = {
202 .owner = THIS_MODULE,
203 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
204 .algo_data = &pcf_isa_data,
205 .name = "i2c-elektor",
206 };
207
elektor_match(struct device * dev,unsigned int id)208 static int __devinit elektor_match(struct device *dev, unsigned int id)
209 {
210 #ifdef __alpha__
211 /* check to see we have memory mapped PCF8584 connected to the
212 Cypress cy82c693 PCI-ISA bridge as on UP2000 board */
213 if (base == 0) {
214 struct pci_dev *cy693_dev;
215
216 cy693_dev = pci_get_device(PCI_VENDOR_ID_CONTAQ,
217 PCI_DEVICE_ID_CONTAQ_82C693, NULL);
218 if (cy693_dev) {
219 unsigned char config;
220 /* yeap, we've found cypress, let's check config */
221 if (!pci_read_config_byte(cy693_dev, 0x47, &config)) {
222
223 dev_dbg(dev, "found cy82c693, config "
224 "register 0x47 = 0x%02x\n", config);
225
226 /* UP2000 board has this register set to 0xe1,
227 but the most significant bit as seems can be
228 reset during the proper initialisation
229 sequence if guys from API decides to do that
230 (so, we can even enable Tsunami Pchip
231 window for the upper 1 Gb) */
232
233 /* so just check for ROMCS at 0xe0000,
234 ROMCS enabled for writes
235 and external XD Bus buffer in use. */
236 if ((config & 0x7f) == 0x61) {
237 /* seems to be UP2000 like board */
238 base = 0xe0000;
239 mmapped = 1;
240 /* UP2000 drives ISA with
241 8.25 MHz (PCI/4) clock
242 (this can be read from cypress) */
243 clock = I2C_PCF_CLK | I2C_PCF_TRNS90;
244 dev_info(dev, "found API UP2000 like "
245 "board, will probe PCF8584 "
246 "later\n");
247 }
248 }
249 pci_dev_put(cy693_dev);
250 }
251 }
252 #endif
253
254 /* sanity checks for mmapped I/O */
255 if (mmapped && base < 0xc8000) {
256 dev_err(dev, "incorrect base address (%#x) specified "
257 "for mmapped I/O\n", base);
258 return 0;
259 }
260
261 if (base == 0) {
262 base = DEFAULT_BASE;
263 }
264 return 1;
265 }
266
elektor_probe(struct device * dev,unsigned int id)267 static int __devinit elektor_probe(struct device *dev, unsigned int id)
268 {
269 init_waitqueue_head(&pcf_wait);
270 if (pcf_isa_init())
271 return -ENODEV;
272 pcf_isa_ops.dev.parent = dev;
273 if (i2c_pcf_add_bus(&pcf_isa_ops) < 0)
274 goto fail;
275
276 dev_info(dev, "found device at %#x\n", base);
277
278 return 0;
279
280 fail:
281 if (irq > 0) {
282 disable_irq(irq);
283 free_irq(irq, NULL);
284 }
285
286 if (!mmapped) {
287 ioport_unmap(base_iomem);
288 release_region(base, 2);
289 } else {
290 iounmap(base_iomem);
291 release_mem_region(base, 2);
292 }
293 return -ENODEV;
294 }
295
elektor_remove(struct device * dev,unsigned int id)296 static int __devexit elektor_remove(struct device *dev, unsigned int id)
297 {
298 i2c_del_adapter(&pcf_isa_ops);
299
300 if (irq > 0) {
301 disable_irq(irq);
302 free_irq(irq, NULL);
303 }
304
305 if (!mmapped) {
306 ioport_unmap(base_iomem);
307 release_region(base, 2);
308 } else {
309 iounmap(base_iomem);
310 release_mem_region(base, 2);
311 }
312
313 return 0;
314 }
315
316 static struct isa_driver i2c_elektor_driver = {
317 .match = elektor_match,
318 .probe = elektor_probe,
319 .remove = __devexit_p(elektor_remove),
320 .driver = {
321 .owner = THIS_MODULE,
322 .name = "i2c-elektor",
323 },
324 };
325
i2c_pcfisa_init(void)326 static int __init i2c_pcfisa_init(void)
327 {
328 return isa_register_driver(&i2c_elektor_driver, 1);
329 }
330
i2c_pcfisa_exit(void)331 static void __exit i2c_pcfisa_exit(void)
332 {
333 isa_unregister_driver(&i2c_elektor_driver);
334 }
335
336 MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
337 MODULE_DESCRIPTION("I2C-Bus adapter routines for PCF8584 ISA bus adapter");
338 MODULE_LICENSE("GPL");
339
340 module_param(base, int, 0);
341 module_param(irq, int, 0);
342 module_param(clock, int, 0);
343 module_param(own, int, 0);
344 module_param(mmapped, int, 0);
345
346 module_init(i2c_pcfisa_init);
347 module_exit(i2c_pcfisa_exit);
348