x86/xen: resume timer irqs early
[linux/fpc-iii.git] / drivers / i2c / busses / scx200_acb.c
blob2d1d2c5653fb4d368f09f7f9dfeb724246dac0fc
1 /*
2 Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
4 National Semiconductor SCx200 ACCESS.bus support
5 Also supports the AMD CS5535 and AMD CS5536
7 Based on i2c-keywest.c which is:
8 Copyright (c) 2001 Benjamin Herrenschmidt <benh@kernel.crashing.org>
9 Copyright (c) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
11 This program is free software; you can redistribute it and/or
12 modify it under the terms of the GNU General Public License as
13 published by the Free Software Foundation; either version 2 of the
14 License, or (at your option) any later version.
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 General Public License for more details.
21 You should have received a copy of the GNU General Public License
22 along with this program; if not, write to the Free Software
23 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/kernel.h>
31 #include <linux/init.h>
32 #include <linux/i2c.h>
33 #include <linux/pci.h>
34 #include <linux/platform_device.h>
35 #include <linux/delay.h>
36 #include <linux/mutex.h>
37 #include <linux/slab.h>
38 #include <linux/io.h>
40 #include <linux/scx200.h>
42 MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
43 MODULE_DESCRIPTION("NatSemi SCx200 ACCESS.bus Driver");
44 MODULE_ALIAS("platform:cs5535-smb");
45 MODULE_LICENSE("GPL");
47 #define MAX_DEVICES 4
48 static int base[MAX_DEVICES] = { 0x820, 0x840 };
49 module_param_array(base, int, NULL, 0);
50 MODULE_PARM_DESC(base, "Base addresses for the ACCESS.bus controllers");
52 #define POLL_TIMEOUT (HZ/5)
54 enum scx200_acb_state {
55 state_idle,
56 state_address,
57 state_command,
58 state_repeat_start,
59 state_quick,
60 state_read,
61 state_write,
64 static const char *scx200_acb_state_name[] = {
65 "idle",
66 "address",
67 "command",
68 "repeat_start",
69 "quick",
70 "read",
71 "write",
74 /* Physical interface */
75 struct scx200_acb_iface {
76 struct scx200_acb_iface *next;
77 struct i2c_adapter adapter;
78 unsigned base;
79 struct mutex mutex;
81 /* State machine data */
82 enum scx200_acb_state state;
83 int result;
84 u8 address_byte;
85 u8 command;
86 u8 *ptr;
87 char needs_reset;
88 unsigned len;
91 /* Register Definitions */
92 #define ACBSDA (iface->base + 0)
93 #define ACBST (iface->base + 1)
94 #define ACBST_SDAST 0x40 /* SDA Status */
95 #define ACBST_BER 0x20
96 #define ACBST_NEGACK 0x10 /* Negative Acknowledge */
97 #define ACBST_STASTR 0x08 /* Stall After Start */
98 #define ACBST_MASTER 0x02
99 #define ACBCST (iface->base + 2)
100 #define ACBCST_BB 0x02
101 #define ACBCTL1 (iface->base + 3)
102 #define ACBCTL1_STASTRE 0x80
103 #define ACBCTL1_NMINTE 0x40
104 #define ACBCTL1_ACK 0x10
105 #define ACBCTL1_STOP 0x02
106 #define ACBCTL1_START 0x01
107 #define ACBADDR (iface->base + 4)
108 #define ACBCTL2 (iface->base + 5)
109 #define ACBCTL2_ENABLE 0x01
111 /************************************************************************/
113 static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
115 const char *errmsg;
117 dev_dbg(&iface->adapter.dev, "state %s, status = 0x%02x\n",
118 scx200_acb_state_name[iface->state], status);
120 if (status & ACBST_BER) {
121 errmsg = "bus error";
122 goto error;
124 if (!(status & ACBST_MASTER)) {
125 errmsg = "not master";
126 goto error;
128 if (status & ACBST_NEGACK) {
129 dev_dbg(&iface->adapter.dev, "negative ack in state %s\n",
130 scx200_acb_state_name[iface->state]);
132 iface->state = state_idle;
133 iface->result = -ENXIO;
135 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
136 outb(ACBST_STASTR | ACBST_NEGACK, ACBST);
138 /* Reset the status register */
139 outb(0, ACBST);
140 return;
143 switch (iface->state) {
144 case state_idle:
145 dev_warn(&iface->adapter.dev, "interrupt in idle state\n");
146 break;
148 case state_address:
149 /* Do a pointer write first */
150 outb(iface->address_byte & ~1, ACBSDA);
152 iface->state = state_command;
153 break;
155 case state_command:
156 outb(iface->command, ACBSDA);
158 if (iface->address_byte & 1)
159 iface->state = state_repeat_start;
160 else
161 iface->state = state_write;
162 break;
164 case state_repeat_start:
165 outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
166 /* fallthrough */
168 case state_quick:
169 if (iface->address_byte & 1) {
170 if (iface->len == 1)
171 outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
172 else
173 outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
174 outb(iface->address_byte, ACBSDA);
176 iface->state = state_read;
177 } else {
178 outb(iface->address_byte, ACBSDA);
180 iface->state = state_write;
182 break;
184 case state_read:
185 /* Set ACK if _next_ byte will be the last one */
186 if (iface->len == 2)
187 outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
188 else
189 outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
191 if (iface->len == 1) {
192 iface->result = 0;
193 iface->state = state_idle;
194 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
197 *iface->ptr++ = inb(ACBSDA);
198 --iface->len;
200 break;
202 case state_write:
203 if (iface->len == 0) {
204 iface->result = 0;
205 iface->state = state_idle;
206 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
207 break;
210 outb(*iface->ptr++, ACBSDA);
211 --iface->len;
213 break;
216 return;
218 error:
219 dev_err(&iface->adapter.dev,
220 "%s in state %s (addr=0x%02x, len=%d, status=0x%02x)\n", errmsg,
221 scx200_acb_state_name[iface->state], iface->address_byte,
222 iface->len, status);
224 iface->state = state_idle;
225 iface->result = -EIO;
226 iface->needs_reset = 1;
229 static void scx200_acb_poll(struct scx200_acb_iface *iface)
231 u8 status;
232 unsigned long timeout;
234 timeout = jiffies + POLL_TIMEOUT;
235 while (1) {
236 status = inb(ACBST);
238 /* Reset the status register to avoid the hang */
239 outb(0, ACBST);
241 if ((status & (ACBST_SDAST|ACBST_BER|ACBST_NEGACK)) != 0) {
242 scx200_acb_machine(iface, status);
243 return;
245 if (time_after(jiffies, timeout))
246 break;
247 cpu_relax();
248 cond_resched();
251 dev_err(&iface->adapter.dev, "timeout in state %s\n",
252 scx200_acb_state_name[iface->state]);
254 iface->state = state_idle;
255 iface->result = -EIO;
256 iface->needs_reset = 1;
259 static void scx200_acb_reset(struct scx200_acb_iface *iface)
261 /* Disable the ACCESS.bus device and Configure the SCL
262 frequency: 16 clock cycles */
263 outb(0x70, ACBCTL2);
264 /* Polling mode */
265 outb(0, ACBCTL1);
266 /* Disable slave address */
267 outb(0, ACBADDR);
268 /* Enable the ACCESS.bus device */
269 outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
270 /* Free STALL after START */
271 outb(inb(ACBCTL1) & ~(ACBCTL1_STASTRE | ACBCTL1_NMINTE), ACBCTL1);
272 /* Send a STOP */
273 outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
274 /* Clear BER, NEGACK and STASTR bits */
275 outb(ACBST_BER | ACBST_NEGACK | ACBST_STASTR, ACBST);
276 /* Clear BB bit */
277 outb(inb(ACBCST) | ACBCST_BB, ACBCST);
280 static s32 scx200_acb_smbus_xfer(struct i2c_adapter *adapter,
281 u16 address, unsigned short flags,
282 char rw, u8 command, int size,
283 union i2c_smbus_data *data)
285 struct scx200_acb_iface *iface = i2c_get_adapdata(adapter);
286 int len;
287 u8 *buffer;
288 u16 cur_word;
289 int rc;
291 switch (size) {
292 case I2C_SMBUS_QUICK:
293 len = 0;
294 buffer = NULL;
295 break;
297 case I2C_SMBUS_BYTE:
298 len = 1;
299 buffer = rw ? &data->byte : &command;
300 break;
302 case I2C_SMBUS_BYTE_DATA:
303 len = 1;
304 buffer = &data->byte;
305 break;
307 case I2C_SMBUS_WORD_DATA:
308 len = 2;
309 cur_word = cpu_to_le16(data->word);
310 buffer = (u8 *)&cur_word;
311 break;
313 case I2C_SMBUS_I2C_BLOCK_DATA:
314 len = data->block[0];
315 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
316 return -EINVAL;
317 buffer = &data->block[1];
318 break;
320 default:
321 return -EINVAL;
324 dev_dbg(&adapter->dev,
325 "size=%d, address=0x%x, command=0x%x, len=%d, read=%d\n",
326 size, address, command, len, rw);
328 if (!len && rw == I2C_SMBUS_READ) {
329 dev_dbg(&adapter->dev, "zero length read\n");
330 return -EINVAL;
333 mutex_lock(&iface->mutex);
335 iface->address_byte = (address << 1) | rw;
336 iface->command = command;
337 iface->ptr = buffer;
338 iface->len = len;
339 iface->result = -EINVAL;
340 iface->needs_reset = 0;
342 outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
344 if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE)
345 iface->state = state_quick;
346 else
347 iface->state = state_address;
349 while (iface->state != state_idle)
350 scx200_acb_poll(iface);
352 if (iface->needs_reset)
353 scx200_acb_reset(iface);
355 rc = iface->result;
357 mutex_unlock(&iface->mutex);
359 if (rc == 0 && size == I2C_SMBUS_WORD_DATA && rw == I2C_SMBUS_READ)
360 data->word = le16_to_cpu(cur_word);
362 #ifdef DEBUG
363 dev_dbg(&adapter->dev, "transfer done, result: %d", rc);
364 if (buffer) {
365 int i;
366 printk(" data:");
367 for (i = 0; i < len; ++i)
368 printk(" %02x", buffer[i]);
370 printk("\n");
371 #endif
373 return rc;
376 static u32 scx200_acb_func(struct i2c_adapter *adapter)
378 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
379 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
380 I2C_FUNC_SMBUS_I2C_BLOCK;
383 /* For now, we only handle combined mode (smbus) */
384 static const struct i2c_algorithm scx200_acb_algorithm = {
385 .smbus_xfer = scx200_acb_smbus_xfer,
386 .functionality = scx200_acb_func,
389 static struct scx200_acb_iface *scx200_acb_list;
390 static DEFINE_MUTEX(scx200_acb_list_mutex);
392 static int scx200_acb_probe(struct scx200_acb_iface *iface)
394 u8 val;
396 /* Disable the ACCESS.bus device and Configure the SCL
397 frequency: 16 clock cycles */
398 outb(0x70, ACBCTL2);
400 if (inb(ACBCTL2) != 0x70) {
401 pr_debug("ACBCTL2 readback failed\n");
402 return -ENXIO;
405 outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
407 val = inb(ACBCTL1);
408 if (val) {
409 pr_debug("disabled, but ACBCTL1=0x%02x\n", val);
410 return -ENXIO;
413 outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
415 outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
417 val = inb(ACBCTL1);
418 if ((val & ACBCTL1_NMINTE) != ACBCTL1_NMINTE) {
419 pr_debug("enabled, but NMINTE won't be set, ACBCTL1=0x%02x\n",
420 val);
421 return -ENXIO;
424 return 0;
427 static struct scx200_acb_iface *scx200_create_iface(const char *text,
428 struct device *dev, int index)
430 struct scx200_acb_iface *iface;
431 struct i2c_adapter *adapter;
433 iface = kzalloc(sizeof(*iface), GFP_KERNEL);
434 if (!iface) {
435 pr_err("can't allocate memory\n");
436 return NULL;
439 adapter = &iface->adapter;
440 i2c_set_adapdata(adapter, iface);
441 snprintf(adapter->name, sizeof(adapter->name), "%s ACB%d", text, index);
442 adapter->owner = THIS_MODULE;
443 adapter->algo = &scx200_acb_algorithm;
444 adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
445 adapter->dev.parent = dev;
447 mutex_init(&iface->mutex);
449 return iface;
452 static int scx200_acb_create(struct scx200_acb_iface *iface)
454 struct i2c_adapter *adapter;
455 int rc;
457 adapter = &iface->adapter;
459 rc = scx200_acb_probe(iface);
460 if (rc) {
461 pr_warn("probe failed\n");
462 return rc;
465 scx200_acb_reset(iface);
467 if (i2c_add_adapter(adapter) < 0) {
468 pr_err("failed to register\n");
469 return -ENODEV;
472 if (!adapter->dev.parent) {
473 /* If there's no dev, we're tracking (ISA) ifaces manually */
474 mutex_lock(&scx200_acb_list_mutex);
475 iface->next = scx200_acb_list;
476 scx200_acb_list = iface;
477 mutex_unlock(&scx200_acb_list_mutex);
480 return 0;
483 static struct scx200_acb_iface *scx200_create_dev(const char *text,
484 unsigned long base, int index, struct device *dev)
486 struct scx200_acb_iface *iface;
487 int rc;
489 iface = scx200_create_iface(text, dev, index);
491 if (iface == NULL)
492 return NULL;
494 if (!request_region(base, 8, iface->adapter.name)) {
495 pr_err("can't allocate io 0x%lx-0x%lx\n", base, base + 8 - 1);
496 goto errout_free;
499 iface->base = base;
500 rc = scx200_acb_create(iface);
502 if (rc == 0)
503 return iface;
505 release_region(base, 8);
506 errout_free:
507 kfree(iface);
508 return NULL;
511 static int scx200_probe(struct platform_device *pdev)
513 struct scx200_acb_iface *iface;
514 struct resource *res;
516 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
517 if (!res) {
518 dev_err(&pdev->dev, "can't fetch device resource info\n");
519 return -ENODEV;
522 iface = scx200_create_dev("CS5535", res->start, 0, &pdev->dev);
523 if (!iface)
524 return -EIO;
526 dev_info(&pdev->dev, "SCx200 device '%s' registered\n",
527 iface->adapter.name);
528 platform_set_drvdata(pdev, iface);
530 return 0;
533 static void scx200_cleanup_iface(struct scx200_acb_iface *iface)
535 i2c_del_adapter(&iface->adapter);
536 release_region(iface->base, 8);
537 kfree(iface);
540 static int scx200_remove(struct platform_device *pdev)
542 struct scx200_acb_iface *iface;
544 iface = platform_get_drvdata(pdev);
545 scx200_cleanup_iface(iface);
547 return 0;
550 static struct platform_driver scx200_pci_driver = {
551 .driver = {
552 .name = "cs5535-smb",
553 .owner = THIS_MODULE,
555 .probe = scx200_probe,
556 .remove = scx200_remove,
559 static DEFINE_PCI_DEVICE_TABLE(scx200_isa) = {
560 { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE) },
561 { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE) },
562 { 0, }
565 static __init void scx200_scan_isa(void)
567 int i;
569 if (!pci_dev_present(scx200_isa))
570 return;
572 for (i = 0; i < MAX_DEVICES; ++i) {
573 if (base[i] == 0)
574 continue;
576 /* XXX: should we care about failures? */
577 scx200_create_dev("SCx200", base[i], i, NULL);
581 static int __init scx200_acb_init(void)
583 pr_debug("NatSemi SCx200 ACCESS.bus Driver\n");
585 /* First scan for ISA-based devices */
586 scx200_scan_isa(); /* XXX: should we care about errors? */
588 /* If at least one bus was created, init must succeed */
589 if (scx200_acb_list)
590 return 0;
592 /* No ISA devices; register the platform driver for PCI-based devices */
593 return platform_driver_register(&scx200_pci_driver);
596 static void __exit scx200_acb_cleanup(void)
598 struct scx200_acb_iface *iface;
600 platform_driver_unregister(&scx200_pci_driver);
602 mutex_lock(&scx200_acb_list_mutex);
603 while ((iface = scx200_acb_list) != NULL) {
604 scx200_acb_list = iface->next;
605 mutex_unlock(&scx200_acb_list_mutex);
607 scx200_cleanup_iface(iface);
609 mutex_lock(&scx200_acb_list_mutex);
611 mutex_unlock(&scx200_acb_list_mutex);
614 module_init(scx200_acb_init);
615 module_exit(scx200_acb_cleanup);