blob: 7c7eb0cfecebee8eee4b1091a39f92c6ba1bc396 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Uwe Zeisbergerf30c2262006-10-03 23:01:26 +02002 * drivers/i2c/busses/i2c-ibm_iic.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Support for the IIC peripheral on IBM PPC 4xx
5 *
6 * Copyright (c) 2003, 2004 Zultys Technologies.
7 * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
8 *
Stefan Roese217bcec2008-01-27 18:14:45 +01009 * Based on original work by
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 * Ian DaSilva <idasilva@mvista.com>
11 * Armin Kuster <akuster@mvista.com>
12 * Matt Porter <mporter@mvista.com>
13 *
14 * Copyright 2000-2003 MontaVista Software Inc.
15 *
16 * Original driver version was highly leveraged from i2c-elektor.c
17 *
18 * Copyright 1995-97 Simon G. Vogl
19 * 1998-99 Hans Berglund
20 *
Jan Engelhardt96de0e22007-10-19 23:21:04 +020021 * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 * and even Frodo Looijaard <frodol@dds.nl>
23 *
24 * This program is free software; you can redistribute it and/or modify it
25 * under the terms of the GNU General Public License as published by the
26 * Free Software Foundation; either version 2 of the License, or (at your
27 * option) any later version.
28 *
29 */
30
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/module.h>
32#include <linux/kernel.h>
33#include <linux/ioport.h>
34#include <linux/delay.h>
35#include <linux/slab.h>
36#include <linux/init.h>
37#include <linux/interrupt.h>
38#include <asm/irq.h>
39#include <asm/io.h>
40#include <linux/i2c.h>
41#include <linux/i2c-id.h>
42#include <asm/ocp.h>
43#include <asm/ibm4xx.h>
44
45#include "i2c-ibm_iic.h"
46
47#define DRIVER_VERSION "2.1"
48
49MODULE_DESCRIPTION("IBM IIC driver v" DRIVER_VERSION);
50MODULE_LICENSE("GPL");
51
52static int iic_force_poll;
53module_param(iic_force_poll, bool, 0);
54MODULE_PARM_DESC(iic_force_poll, "Force polling mode");
55
56static int iic_force_fast;
57module_param(iic_force_fast, bool, 0);
58MODULE_PARM_DESC(iic_fast_poll, "Force fast mode (400 kHz)");
59
60#define DBG_LEVEL 0
61
62#ifdef DBG
63#undef DBG
64#endif
65
66#ifdef DBG2
67#undef DBG2
68#endif
69
70#if DBG_LEVEL > 0
71# define DBG(f,x...) printk(KERN_DEBUG "ibm-iic" f, ##x)
72#else
73# define DBG(f,x...) ((void)0)
74#endif
75#if DBG_LEVEL > 1
76# define DBG2(f,x...) DBG(f, ##x)
77#else
78# define DBG2(f,x...) ((void)0)
79#endif
80#if DBG_LEVEL > 2
81static void dump_iic_regs(const char* header, struct ibm_iic_private* dev)
82{
83 volatile struct iic_regs __iomem *iic = dev->vaddr;
84 printk(KERN_DEBUG "ibm-iic%d: %s\n", dev->idx, header);
85 printk(KERN_DEBUG " cntl = 0x%02x, mdcntl = 0x%02x\n"
86 KERN_DEBUG " sts = 0x%02x, extsts = 0x%02x\n"
87 KERN_DEBUG " clkdiv = 0x%02x, xfrcnt = 0x%02x\n"
88 KERN_DEBUG " xtcntlss = 0x%02x, directcntl = 0x%02x\n",
Stefan Roese217bcec2008-01-27 18:14:45 +010089 in_8(&iic->cntl), in_8(&iic->mdcntl), in_8(&iic->sts),
90 in_8(&iic->extsts), in_8(&iic->clkdiv), in_8(&iic->xfrcnt),
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 in_8(&iic->xtcntlss), in_8(&iic->directcntl));
92}
93# define DUMP_REGS(h,dev) dump_iic_regs((h),(dev))
94#else
95# define DUMP_REGS(h,dev) ((void)0)
96#endif
97
98/* Bus timings (in ns) for bit-banging */
99static struct i2c_timings {
100 unsigned int hd_sta;
101 unsigned int su_sto;
102 unsigned int low;
103 unsigned int high;
104 unsigned int buf;
105} timings [] = {
106/* Standard mode (100 KHz) */
107{
108 .hd_sta = 4000,
109 .su_sto = 4000,
110 .low = 4700,
111 .high = 4000,
112 .buf = 4700,
113},
114/* Fast mode (400 KHz) */
115{
116 .hd_sta = 600,
117 .su_sto = 600,
118 .low = 1300,
119 .high = 600,
120 .buf = 1300,
121}};
122
123/* Enable/disable interrupt generation */
124static inline void iic_interrupt_mode(struct ibm_iic_private* dev, int enable)
125{
126 out_8(&dev->vaddr->intmsk, enable ? INTRMSK_EIMTC : 0);
127}
Stefan Roese217bcec2008-01-27 18:14:45 +0100128
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129/*
130 * Initialize IIC interface.
131 */
132static void iic_dev_init(struct ibm_iic_private* dev)
133{
134 volatile struct iic_regs __iomem *iic = dev->vaddr;
135
136 DBG("%d: init\n", dev->idx);
Stefan Roese217bcec2008-01-27 18:14:45 +0100137
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 /* Clear master address */
139 out_8(&iic->lmadr, 0);
140 out_8(&iic->hmadr, 0);
141
142 /* Clear slave address */
143 out_8(&iic->lsadr, 0);
144 out_8(&iic->hsadr, 0);
145
146 /* Clear status & extended status */
147 out_8(&iic->sts, STS_SCMP | STS_IRQA);
148 out_8(&iic->extsts, EXTSTS_IRQP | EXTSTS_IRQD | EXTSTS_LA
149 | EXTSTS_ICT | EXTSTS_XFRA);
150
151 /* Set clock divider */
152 out_8(&iic->clkdiv, dev->clckdiv);
153
154 /* Clear transfer count */
155 out_8(&iic->xfrcnt, 0);
156
157 /* Clear extended control and status */
158 out_8(&iic->xtcntlss, XTCNTLSS_SRC | XTCNTLSS_SRS | XTCNTLSS_SWC
159 | XTCNTLSS_SWS);
160
161 /* Clear control register */
162 out_8(&iic->cntl, 0);
Stefan Roese217bcec2008-01-27 18:14:45 +0100163
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 /* Enable interrupts if possible */
165 iic_interrupt_mode(dev, dev->irq >= 0);
166
167 /* Set mode control */
168 out_8(&iic->mdcntl, MDCNTL_FMDB | MDCNTL_EINT | MDCNTL_EUBS
169 | (dev->fast_mode ? MDCNTL_FSM : 0));
170
171 DUMP_REGS("iic_init", dev);
172}
173
Stefan Roese217bcec2008-01-27 18:14:45 +0100174/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 * Reset IIC interface
176 */
177static void iic_dev_reset(struct ibm_iic_private* dev)
178{
179 volatile struct iic_regs __iomem *iic = dev->vaddr;
180 int i;
181 u8 dc;
Stefan Roese217bcec2008-01-27 18:14:45 +0100182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 DBG("%d: soft reset\n", dev->idx);
184 DUMP_REGS("reset", dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 /* Place chip in the reset state */
187 out_8(&iic->xtcntlss, XTCNTLSS_SRST);
Stefan Roese217bcec2008-01-27 18:14:45 +0100188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 /* Check if bus is free */
Stefan Roese217bcec2008-01-27 18:14:45 +0100190 dc = in_8(&iic->directcntl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 if (!DIRCTNL_FREE(dc)){
192 DBG("%d: trying to regain bus control\n", dev->idx);
Stefan Roese217bcec2008-01-27 18:14:45 +0100193
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 /* Try to set bus free state */
Stefan Roese217bcec2008-01-27 18:14:45 +0100195 out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
196
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 /* Wait until we regain bus control */
198 for (i = 0; i < 100; ++i){
199 dc = in_8(&iic->directcntl);
200 if (DIRCTNL_FREE(dc))
201 break;
Stefan Roese217bcec2008-01-27 18:14:45 +0100202
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 /* Toggle SCL line */
204 dc ^= DIRCNTL_SCC;
205 out_8(&iic->directcntl, dc);
206 udelay(10);
207 dc ^= DIRCNTL_SCC;
208 out_8(&iic->directcntl, dc);
Stefan Roese217bcec2008-01-27 18:14:45 +0100209
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 /* be nice */
211 cond_resched();
212 }
213 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 /* Remove reset */
216 out_8(&iic->xtcntlss, 0);
Stefan Roese217bcec2008-01-27 18:14:45 +0100217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 /* Reinitialize interface */
219 iic_dev_init(dev);
220}
221
222/*
223 * Do 0-length transaction using bit-banging through IIC_DIRECTCNTL register.
224 */
225
226/* Wait for SCL and/or SDA to be high */
227static int iic_dc_wait(volatile struct iic_regs __iomem *iic, u8 mask)
228{
229 unsigned long x = jiffies + HZ / 28 + 2;
230 while ((in_8(&iic->directcntl) & mask) != mask){
231 if (unlikely(time_after(jiffies, x)))
232 return -1;
233 cond_resched();
234 }
235 return 0;
236}
237
238static int iic_smbus_quick(struct ibm_iic_private* dev, const struct i2c_msg* p)
239{
240 volatile struct iic_regs __iomem *iic = dev->vaddr;
241 const struct i2c_timings* t = &timings[dev->fast_mode ? 1 : 0];
242 u8 mask, v, sda;
243 int i, res;
244
245 /* Only 7-bit addresses are supported */
246 if (unlikely(p->flags & I2C_M_TEN)){
247 DBG("%d: smbus_quick - 10 bit addresses are not supported\n",
248 dev->idx);
249 return -EINVAL;
250 }
251
252 DBG("%d: smbus_quick(0x%02x)\n", dev->idx, p->addr);
253
254 /* Reset IIC interface */
255 out_8(&iic->xtcntlss, XTCNTLSS_SRST);
256
257 /* Wait for bus to become free */
258 out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
259 if (unlikely(iic_dc_wait(iic, DIRCNTL_MSDA | DIRCNTL_MSC)))
260 goto err;
261 ndelay(t->buf);
262
263 /* START */
264 out_8(&iic->directcntl, DIRCNTL_SCC);
265 sda = 0;
266 ndelay(t->hd_sta);
267
268 /* Send address */
269 v = (u8)((p->addr << 1) | ((p->flags & I2C_M_RD) ? 1 : 0));
270 for (i = 0, mask = 0x80; i < 8; ++i, mask >>= 1){
271 out_8(&iic->directcntl, sda);
272 ndelay(t->low / 2);
273 sda = (v & mask) ? DIRCNTL_SDAC : 0;
274 out_8(&iic->directcntl, sda);
275 ndelay(t->low / 2);
276
277 out_8(&iic->directcntl, DIRCNTL_SCC | sda);
278 if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
279 goto err;
280 ndelay(t->high);
281 }
282
283 /* ACK */
284 out_8(&iic->directcntl, sda);
285 ndelay(t->low / 2);
286 out_8(&iic->directcntl, DIRCNTL_SDAC);
287 ndelay(t->low / 2);
288 out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
289 if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
290 goto err;
291 res = (in_8(&iic->directcntl) & DIRCNTL_MSDA) ? -EREMOTEIO : 1;
292 ndelay(t->high);
293
294 /* STOP */
295 out_8(&iic->directcntl, 0);
296 ndelay(t->low);
297 out_8(&iic->directcntl, DIRCNTL_SCC);
298 if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
299 goto err;
300 ndelay(t->su_sto);
301 out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
302
303 ndelay(t->buf);
304
305 DBG("%d: smbus_quick -> %s\n", dev->idx, res ? "NACK" : "ACK");
306out:
307 /* Remove reset */
308 out_8(&iic->xtcntlss, 0);
309
310 /* Reinitialize interface */
311 iic_dev_init(dev);
312
313 return res;
314err:
315 DBG("%d: smbus_quick - bus is stuck\n", dev->idx);
316 res = -EREMOTEIO;
317 goto out;
318}
319
320/*
321 * IIC interrupt handler
322 */
David Howells7d12e782006-10-05 14:55:46 +0100323static irqreturn_t iic_handler(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324{
325 struct ibm_iic_private* dev = (struct ibm_iic_private*)dev_id;
326 volatile struct iic_regs __iomem *iic = dev->vaddr;
Stefan Roese217bcec2008-01-27 18:14:45 +0100327
328 DBG2("%d: irq handler, STS = 0x%02x, EXTSTS = 0x%02x\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 dev->idx, in_8(&iic->sts), in_8(&iic->extsts));
Stefan Roese217bcec2008-01-27 18:14:45 +0100330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 /* Acknowledge IRQ and wakeup iic_wait_for_tc */
332 out_8(&iic->sts, STS_IRQA | STS_SCMP);
333 wake_up_interruptible(&dev->wq);
Stefan Roese217bcec2008-01-27 18:14:45 +0100334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 return IRQ_HANDLED;
336}
337
338/*
339 * Get master transfer result and clear errors if any.
340 * Returns the number of actually transferred bytes or error (<0)
341 */
342static int iic_xfer_result(struct ibm_iic_private* dev)
343{
Stefan Roese217bcec2008-01-27 18:14:45 +0100344 volatile struct iic_regs __iomem *iic = dev->vaddr;
345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 if (unlikely(in_8(&iic->sts) & STS_ERR)){
Stefan Roese217bcec2008-01-27 18:14:45 +0100347 DBG("%d: xfer error, EXTSTS = 0x%02x\n", dev->idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 in_8(&iic->extsts));
Stefan Roese217bcec2008-01-27 18:14:45 +0100349
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 /* Clear errors and possible pending IRQs */
Stefan Roese217bcec2008-01-27 18:14:45 +0100351 out_8(&iic->extsts, EXTSTS_IRQP | EXTSTS_IRQD |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 EXTSTS_LA | EXTSTS_ICT | EXTSTS_XFRA);
Stefan Roese217bcec2008-01-27 18:14:45 +0100353
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 /* Flush master data buffer */
355 out_8(&iic->mdcntl, in_8(&iic->mdcntl) | MDCNTL_FMDB);
Stefan Roese217bcec2008-01-27 18:14:45 +0100356
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 /* Is bus free?
358 * If error happened during combined xfer
359 * IIC interface is usually stuck in some strange
360 * state, the only way out - soft reset.
361 */
362 if ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){
363 DBG("%d: bus is stuck, resetting\n", dev->idx);
364 iic_dev_reset(dev);
365 }
366 return -EREMOTEIO;
367 }
368 else
369 return in_8(&iic->xfrcnt) & XFRCNT_MTC_MASK;
370}
371
372/*
373 * Try to abort active transfer.
374 */
375static void iic_abort_xfer(struct ibm_iic_private* dev)
376{
377 volatile struct iic_regs __iomem *iic = dev->vaddr;
378 unsigned long x;
Stefan Roese217bcec2008-01-27 18:14:45 +0100379
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 DBG("%d: iic_abort_xfer\n", dev->idx);
Stefan Roese217bcec2008-01-27 18:14:45 +0100381
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 out_8(&iic->cntl, CNTL_HMT);
Stefan Roese217bcec2008-01-27 18:14:45 +0100383
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 /*
385 * Wait for the abort command to complete.
386 * It's not worth to be optimized, just poll (timeout >= 1 tick)
387 */
388 x = jiffies + 2;
389 while ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){
390 if (time_after(jiffies, x)){
391 DBG("%d: abort timeout, resetting...\n", dev->idx);
392 iic_dev_reset(dev);
393 return;
394 }
395 schedule();
396 }
397
398 /* Just to clear errors */
399 iic_xfer_result(dev);
400}
401
402/*
403 * Wait for master transfer to complete.
404 * It puts current process to sleep until we get interrupt or timeout expires.
405 * Returns the number of transferred bytes or error (<0)
406 */
407static int iic_wait_for_tc(struct ibm_iic_private* dev){
Stefan Roese217bcec2008-01-27 18:14:45 +0100408
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 volatile struct iic_regs __iomem *iic = dev->vaddr;
410 int ret = 0;
Stefan Roese217bcec2008-01-27 18:14:45 +0100411
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 if (dev->irq >= 0){
413 /* Interrupt mode */
Stefan Roese217bcec2008-01-27 18:14:45 +0100414 ret = wait_event_interruptible_timeout(dev->wq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 !(in_8(&iic->sts) & STS_PT), dev->adap.timeout * HZ);
416
417 if (unlikely(ret < 0))
418 DBG("%d: wait interrupted\n", dev->idx);
419 else if (unlikely(in_8(&iic->sts) & STS_PT)){
420 DBG("%d: wait timeout\n", dev->idx);
421 ret = -ETIMEDOUT;
422 }
423 }
424 else {
425 /* Polling mode */
426 unsigned long x = jiffies + dev->adap.timeout * HZ;
Stefan Roese217bcec2008-01-27 18:14:45 +0100427
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 while (in_8(&iic->sts) & STS_PT){
429 if (unlikely(time_after(jiffies, x))){
430 DBG("%d: poll timeout\n", dev->idx);
431 ret = -ETIMEDOUT;
432 break;
433 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100434
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 if (unlikely(signal_pending(current))){
436 DBG("%d: poll interrupted\n", dev->idx);
437 ret = -ERESTARTSYS;
438 break;
439 }
440 schedule();
Stefan Roese217bcec2008-01-27 18:14:45 +0100441 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100443
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 if (unlikely(ret < 0))
445 iic_abort_xfer(dev);
446 else
447 ret = iic_xfer_result(dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100448
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 DBG2("%d: iic_wait_for_tc -> %d\n", dev->idx, ret);
Stefan Roese217bcec2008-01-27 18:14:45 +0100450
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 return ret;
452}
453
454/*
455 * Low level master transfer routine
456 */
Stefan Roese217bcec2008-01-27 18:14:45 +0100457static int iic_xfer_bytes(struct ibm_iic_private* dev, struct i2c_msg* pm,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 int combined_xfer)
459{
460 volatile struct iic_regs __iomem *iic = dev->vaddr;
461 char* buf = pm->buf;
462 int i, j, loops, ret = 0;
463 int len = pm->len;
464
465 u8 cntl = (in_8(&iic->cntl) & CNTL_AMD) | CNTL_PT;
466 if (pm->flags & I2C_M_RD)
467 cntl |= CNTL_RW;
Stefan Roese217bcec2008-01-27 18:14:45 +0100468
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 loops = (len + 3) / 4;
470 for (i = 0; i < loops; ++i, len -= 4){
471 int count = len > 4 ? 4 : len;
472 u8 cmd = cntl | ((count - 1) << CNTL_TCT_SHIFT);
Stefan Roese217bcec2008-01-27 18:14:45 +0100473
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 if (!(cntl & CNTL_RW))
475 for (j = 0; j < count; ++j)
476 out_8((void __iomem *)&iic->mdbuf, *buf++);
Stefan Roese217bcec2008-01-27 18:14:45 +0100477
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 if (i < loops - 1)
479 cmd |= CNTL_CHT;
480 else if (combined_xfer)
481 cmd |= CNTL_RPST;
Stefan Roese217bcec2008-01-27 18:14:45 +0100482
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 DBG2("%d: xfer_bytes, %d, CNTL = 0x%02x\n", dev->idx, count, cmd);
Stefan Roese217bcec2008-01-27 18:14:45 +0100484
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 /* Start transfer */
486 out_8(&iic->cntl, cmd);
Stefan Roese217bcec2008-01-27 18:14:45 +0100487
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 /* Wait for completion */
489 ret = iic_wait_for_tc(dev);
490
491 if (unlikely(ret < 0))
492 break;
493 else if (unlikely(ret != count)){
Stefan Roese217bcec2008-01-27 18:14:45 +0100494 DBG("%d: xfer_bytes, requested %d, transfered %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 dev->idx, count, ret);
Stefan Roese217bcec2008-01-27 18:14:45 +0100496
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 /* If it's not a last part of xfer, abort it */
498 if (combined_xfer || (i < loops - 1))
499 iic_abort_xfer(dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100500
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 ret = -EREMOTEIO;
Stefan Roese217bcec2008-01-27 18:14:45 +0100502 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100504
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 if (cntl & CNTL_RW)
506 for (j = 0; j < count; ++j)
507 *buf++ = in_8((void __iomem *)&iic->mdbuf);
508 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100509
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 return ret > 0 ? 0 : ret;
511}
512
513/*
514 * Set target slave address for master transfer
515 */
516static inline void iic_address(struct ibm_iic_private* dev, struct i2c_msg* msg)
517{
518 volatile struct iic_regs __iomem *iic = dev->vaddr;
519 u16 addr = msg->addr;
Stefan Roese217bcec2008-01-27 18:14:45 +0100520
521 DBG2("%d: iic_address, 0x%03x (%d-bit)\n", dev->idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 addr, msg->flags & I2C_M_TEN ? 10 : 7);
Stefan Roese217bcec2008-01-27 18:14:45 +0100523
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 if (msg->flags & I2C_M_TEN){
525 out_8(&iic->cntl, CNTL_AMD);
526 out_8(&iic->lmadr, addr);
527 out_8(&iic->hmadr, 0xf0 | ((addr >> 7) & 0x06));
528 }
529 else {
530 out_8(&iic->cntl, 0);
531 out_8(&iic->lmadr, addr << 1);
532 }
533}
534
535static inline int iic_invalid_address(const struct i2c_msg* p)
536{
537 return (p->addr > 0x3ff) || (!(p->flags & I2C_M_TEN) && (p->addr > 0x7f));
538}
539
Stefan Roese217bcec2008-01-27 18:14:45 +0100540static inline int iic_address_neq(const struct i2c_msg* p1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 const struct i2c_msg* p2)
542{
Stefan Roese217bcec2008-01-27 18:14:45 +0100543 return (p1->addr != p2->addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 || ((p1->flags & I2C_M_TEN) != (p2->flags & I2C_M_TEN));
Stefan Roese217bcec2008-01-27 18:14:45 +0100545}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
547/*
Stefan Roese217bcec2008-01-27 18:14:45 +0100548 * Generic master transfer entrypoint.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 * Returns the number of processed messages or error (<0)
550 */
551static int iic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
552{
553 struct ibm_iic_private* dev = (struct ibm_iic_private*)(i2c_get_adapdata(adap));
554 volatile struct iic_regs __iomem *iic = dev->vaddr;
555 int i, ret = 0;
Stefan Roese217bcec2008-01-27 18:14:45 +0100556
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 DBG2("%d: iic_xfer, %d msg(s)\n", dev->idx, num);
Stefan Roese217bcec2008-01-27 18:14:45 +0100558
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 if (!num)
560 return 0;
Stefan Roese217bcec2008-01-27 18:14:45 +0100561
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 /* Check the sanity of the passed messages.
563 * Uhh, generic i2c layer is more suitable place for such code...
564 */
565 if (unlikely(iic_invalid_address(&msgs[0]))){
Stefan Roese217bcec2008-01-27 18:14:45 +0100566 DBG("%d: invalid address 0x%03x (%d-bit)\n", dev->idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 msgs[0].addr, msgs[0].flags & I2C_M_TEN ? 10 : 7);
568 return -EINVAL;
Stefan Roese217bcec2008-01-27 18:14:45 +0100569 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 for (i = 0; i < num; ++i){
571 if (unlikely(msgs[i].len <= 0)){
572 if (num == 1 && !msgs[0].len){
573 /* Special case for I2C_SMBUS_QUICK emulation.
574 * IBM IIC doesn't support 0-length transactions
575 * so we have to emulate them using bit-banging.
576 */
577 return iic_smbus_quick(dev, &msgs[0]);
578 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100579 DBG("%d: invalid len %d in msg[%d]\n", dev->idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 msgs[i].len, i);
581 return -EINVAL;
582 }
583 if (unlikely(iic_address_neq(&msgs[0], &msgs[i]))){
584 DBG("%d: invalid addr in msg[%d]\n", dev->idx, i);
585 return -EINVAL;
586 }
587 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100588
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 /* Check bus state */
590 if (unlikely((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE)){
591 DBG("%d: iic_xfer, bus is not free\n", dev->idx);
Stefan Roese217bcec2008-01-27 18:14:45 +0100592
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 /* Usually it means something serious has happend.
594 * We *cannot* have unfinished previous transfer
595 * so it doesn't make any sense to try to stop it.
Stefan Roese217bcec2008-01-27 18:14:45 +0100596 * Probably we were not able to recover from the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 * previous error.
598 * The only *reasonable* thing I can think of here
599 * is soft reset. --ebs
600 */
601 iic_dev_reset(dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100602
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 if ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){
604 DBG("%d: iic_xfer, bus is still not free\n", dev->idx);
605 return -EREMOTEIO;
606 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100607 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 else {
609 /* Flush master data buffer (just in case) */
610 out_8(&iic->mdcntl, in_8(&iic->mdcntl) | MDCNTL_FMDB);
611 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100612
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 /* Load slave address */
614 iic_address(dev, &msgs[0]);
Stefan Roese217bcec2008-01-27 18:14:45 +0100615
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 /* Do real transfer */
617 for (i = 0; i < num && !ret; ++i)
618 ret = iic_xfer_bytes(dev, &msgs[i], i < num - 1);
619
620 return ret < 0 ? ret : num;
621}
622
623static u32 iic_func(struct i2c_adapter *adap)
624{
625 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
626}
627
Jean Delvare8f9082c2006-09-03 22:39:46 +0200628static const struct i2c_algorithm iic_algo = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 .master_xfer = iic_xfer,
630 .functionality = iic_func
631};
632
633/*
634 * Calculates IICx_CLCKDIV value for a specific OPB clock frequency
635 */
636static inline u8 iic_clckdiv(unsigned int opb)
637{
638 /* Compatibility kludge, should go away after all cards
639 * are fixed to fill correct value for opbfreq.
640 * Previous driver version used hardcoded divider value 4,
641 * it corresponds to OPB frequency from the range (40, 50] MHz
642 */
643 if (!opb){
644 printk(KERN_WARNING "ibm-iic: using compatibility value for OPB freq,"
645 " fix your board specific setup\n");
646 opb = 50000000;
647 }
648
649 /* Convert to MHz */
650 opb /= 1000000;
Stefan Roese217bcec2008-01-27 18:14:45 +0100651
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 if (opb < 20 || opb > 150){
653 printk(KERN_CRIT "ibm-iic: invalid OPB clock frequency %u MHz\n",
654 opb);
655 opb = opb < 20 ? 20 : 150;
656 }
657 return (u8)((opb + 9) / 10 - 1);
658}
659
660/*
661 * Register single IIC interface
662 */
663static int __devinit iic_probe(struct ocp_device *ocp){
664
665 struct ibm_iic_private* dev;
666 struct i2c_adapter* adap;
667 struct ocp_func_iic_data* iic_data = ocp->def->additions;
668 int ret;
Stefan Roese217bcec2008-01-27 18:14:45 +0100669
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 if (!iic_data)
671 printk(KERN_WARNING"ibm-iic%d: missing additional data!\n",
672 ocp->def->index);
673
Deepak Saxena5263ebb2005-10-17 23:09:43 +0200674 if (!(dev = kzalloc(sizeof(*dev), GFP_KERNEL))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 printk(KERN_CRIT "ibm-iic%d: failed to allocate device data\n",
676 ocp->def->index);
677 return -ENOMEM;
678 }
679
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 dev->idx = ocp->def->index;
681 ocp_set_drvdata(ocp, dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100682
Jean-Baptiste Maneyrol31c095b2006-12-10 21:21:29 +0100683 if (!request_mem_region(ocp->def->paddr, sizeof(struct iic_regs),
684 "ibm_iic")) {
685 ret = -EBUSY;
686 goto fail1;
687 }
688
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 if (!(dev->vaddr = ioremap(ocp->def->paddr, sizeof(struct iic_regs)))){
690 printk(KERN_CRIT "ibm-iic%d: failed to ioremap device registers\n",
691 dev->idx);
692 ret = -ENXIO;
693 goto fail2;
694 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100695
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 init_waitqueue_head(&dev->wq);
697
698 dev->irq = iic_force_poll ? -1 : ocp->def->irq;
699 if (dev->irq >= 0){
Steven Cole44bbe872005-05-03 18:21:25 -0600700 /* Disable interrupts until we finish initialization,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 assumes level-sensitive IRQ setup...
702 */
703 iic_interrupt_mode(dev, 0);
704 if (request_irq(dev->irq, iic_handler, 0, "IBM IIC", dev)){
Stefan Roese217bcec2008-01-27 18:14:45 +0100705 printk(KERN_ERR "ibm-iic%d: request_irq %d failed\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 dev->idx, dev->irq);
Stefan Roese217bcec2008-01-27 18:14:45 +0100707 /* Fallback to the polling mode */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 dev->irq = -1;
709 }
710 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100711
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 if (dev->irq < 0)
Stefan Roese217bcec2008-01-27 18:14:45 +0100713 printk(KERN_WARNING "ibm-iic%d: using polling mode\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 dev->idx);
Stefan Roese217bcec2008-01-27 18:14:45 +0100715
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 /* Board specific settings */
717 dev->fast_mode = iic_force_fast ? 1 : (iic_data ? iic_data->fast_mode : 0);
Stefan Roese217bcec2008-01-27 18:14:45 +0100718
719 /* clckdiv is the same for *all* IIC interfaces,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 * but I'd rather make a copy than introduce another global. --ebs
721 */
722 dev->clckdiv = iic_clckdiv(ocp_sys_info.opb_bus_freq);
723 DBG("%d: clckdiv = %d\n", dev->idx, dev->clckdiv);
Stefan Roese217bcec2008-01-27 18:14:45 +0100724
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 /* Initialize IIC interface */
726 iic_dev_init(dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100727
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 /* Register it with i2c layer */
729 adap = &dev->adap;
Jean Delvare12a917f2007-02-13 22:09:03 +0100730 adap->dev.parent = &ocp->dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 strcpy(adap->name, "IBM IIC");
732 i2c_set_adapdata(adap, dev);
Jean Delvarec7a46532005-08-11 23:41:56 +0200733 adap->id = I2C_HW_OCP;
Martin Hicksa4787c02005-12-18 17:18:01 +0100734 adap->class = I2C_CLASS_HWMON;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 adap->algo = &iic_algo;
736 adap->client_register = NULL;
737 adap->client_unregister = NULL;
738 adap->timeout = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739
Stefan Roese7589a322007-10-13 23:56:30 +0200740 /*
741 * If "dev->idx" is negative we consider it as zero.
742 * The reason to do so is to avoid sysfs names that only make
743 * sense when there are multiple adapters.
744 */
745 adap->nr = dev->idx >= 0 ? dev->idx : 0;
746
747 if ((ret = i2c_add_numbered_adapter(adap)) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 printk(KERN_CRIT "ibm-iic%d: failed to register i2c adapter\n",
749 dev->idx);
750 goto fail;
751 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100752
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 printk(KERN_INFO "ibm-iic%d: using %s mode\n", dev->idx,
754 dev->fast_mode ? "fast (400 kHz)" : "standard (100 kHz)");
755
756 return 0;
757
Stefan Roese217bcec2008-01-27 18:14:45 +0100758fail:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 if (dev->irq >= 0){
760 iic_interrupt_mode(dev, 0);
761 free_irq(dev->irq, dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100762 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763
764 iounmap(dev->vaddr);
Stefan Roese217bcec2008-01-27 18:14:45 +0100765fail2:
Jean-Baptiste Maneyrol31c095b2006-12-10 21:21:29 +0100766 release_mem_region(ocp->def->paddr, sizeof(struct iic_regs));
767fail1:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 ocp_set_drvdata(ocp, NULL);
Stefan Roese217bcec2008-01-27 18:14:45 +0100769 kfree(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 return ret;
771}
772
773/*
774 * Cleanup initialized IIC interface
775 */
776static void __devexit iic_remove(struct ocp_device *ocp)
777{
778 struct ibm_iic_private* dev = (struct ibm_iic_private*)ocp_get_drvdata(ocp);
779 BUG_ON(dev == NULL);
780 if (i2c_del_adapter(&dev->adap)){
781 printk(KERN_CRIT "ibm-iic%d: failed to delete i2c adapter :(\n",
782 dev->idx);
783 /* That's *very* bad, just shutdown IRQ ... */
784 if (dev->irq >= 0){
Stefan Roese217bcec2008-01-27 18:14:45 +0100785 iic_interrupt_mode(dev, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 free_irq(dev->irq, dev);
787 dev->irq = -1;
788 }
789 } else {
790 if (dev->irq >= 0){
Stefan Roese217bcec2008-01-27 18:14:45 +0100791 iic_interrupt_mode(dev, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 free_irq(dev->irq, dev);
793 }
794 iounmap(dev->vaddr);
Jean-Baptiste Maneyrol31c095b2006-12-10 21:21:29 +0100795 release_mem_region(ocp->def->paddr, sizeof(struct iic_regs));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 kfree(dev);
797 }
798}
799
Stefan Roese217bcec2008-01-27 18:14:45 +0100800static struct ocp_device_id ibm_iic_ids[] __devinitdata =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801{
802 { .vendor = OCP_VENDOR_IBM, .function = OCP_FUNC_IIC },
803 { .vendor = OCP_VENDOR_INVALID }
804};
805
806MODULE_DEVICE_TABLE(ocp, ibm_iic_ids);
807
808static struct ocp_driver ibm_iic_driver =
809{
810 .name = "iic",
811 .id_table = ibm_iic_ids,
812 .probe = iic_probe,
813 .remove = __devexit_p(iic_remove),
814#if defined(CONFIG_PM)
815 .suspend = NULL,
816 .resume = NULL,
817#endif
818};
819
820static int __init iic_init(void)
821{
822 printk(KERN_INFO "IBM IIC driver v" DRIVER_VERSION "\n");
823 return ocp_register_driver(&ibm_iic_driver);
824}
825
826static void __exit iic_exit(void)
827{
828 ocp_unregister_driver(&ibm_iic_driver);
829}
830
831module_init(iic_init);
832module_exit(iic_exit);