blob: 88f0db73b3647a2b8e995221e950e0cff115a08b [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 *
Sean MacLennan838349b2008-04-22 22:16:47 +02009 * Copyright (c) 2008 PIKA Technologies
10 * Sean MacLennan <smaclennan@pikatech.com>
11 *
Stefan Roese217bcec2008-01-27 18:14:45 +010012 * Based on original work by
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * Ian DaSilva <idasilva@mvista.com>
14 * Armin Kuster <akuster@mvista.com>
15 * Matt Porter <mporter@mvista.com>
16 *
17 * Copyright 2000-2003 MontaVista Software Inc.
18 *
19 * Original driver version was highly leveraged from i2c-elektor.c
20 *
21 * Copyright 1995-97 Simon G. Vogl
22 * 1998-99 Hans Berglund
23 *
Jan Engelhardt96de0e22007-10-19 23:21:04 +020024 * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 * and even Frodo Looijaard <frodol@dds.nl>
26 *
27 * This program is free software; you can redistribute it and/or modify it
28 * under the terms of the GNU General Public License as published by the
29 * Free Software Foundation; either version 2 of the License, or (at your
30 * option) any later version.
31 *
32 */
33
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/module.h>
35#include <linux/kernel.h>
36#include <linux/ioport.h>
37#include <linux/delay.h>
38#include <linux/slab.h>
39#include <linux/init.h>
40#include <linux/interrupt.h>
41#include <asm/irq.h>
42#include <asm/io.h>
43#include <linux/i2c.h>
44#include <linux/i2c-id.h>
Sean MacLennan838349b2008-04-22 22:16:47 +020045#include <linux/of_platform.h>
Sean MacLennanb1204e62008-07-14 22:38:36 +020046#include <linux/of_i2c.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
48#include "i2c-ibm_iic.h"
49
Sean MacLennan838349b2008-04-22 22:16:47 +020050#define DRIVER_VERSION "2.2"
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
52MODULE_DESCRIPTION("IBM IIC driver v" DRIVER_VERSION);
53MODULE_LICENSE("GPL");
54
55static int iic_force_poll;
56module_param(iic_force_poll, bool, 0);
57MODULE_PARM_DESC(iic_force_poll, "Force polling mode");
58
59static int iic_force_fast;
60module_param(iic_force_fast, bool, 0);
Paul Mundt852fb2a2008-04-11 12:07:04 +020061MODULE_PARM_DESC(iic_force_fast, "Force fast mode (400 kHz)");
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63#define DBG_LEVEL 0
64
65#ifdef DBG
66#undef DBG
67#endif
68
69#ifdef DBG2
70#undef DBG2
71#endif
72
73#if DBG_LEVEL > 0
74# define DBG(f,x...) printk(KERN_DEBUG "ibm-iic" f, ##x)
75#else
76# define DBG(f,x...) ((void)0)
77#endif
78#if DBG_LEVEL > 1
79# define DBG2(f,x...) DBG(f, ##x)
80#else
81# define DBG2(f,x...) ((void)0)
82#endif
83#if DBG_LEVEL > 2
84static void dump_iic_regs(const char* header, struct ibm_iic_private* dev)
85{
86 volatile struct iic_regs __iomem *iic = dev->vaddr;
87 printk(KERN_DEBUG "ibm-iic%d: %s\n", dev->idx, header);
88 printk(KERN_DEBUG " cntl = 0x%02x, mdcntl = 0x%02x\n"
89 KERN_DEBUG " sts = 0x%02x, extsts = 0x%02x\n"
90 KERN_DEBUG " clkdiv = 0x%02x, xfrcnt = 0x%02x\n"
91 KERN_DEBUG " xtcntlss = 0x%02x, directcntl = 0x%02x\n",
Stefan Roese217bcec2008-01-27 18:14:45 +010092 in_8(&iic->cntl), in_8(&iic->mdcntl), in_8(&iic->sts),
93 in_8(&iic->extsts), in_8(&iic->clkdiv), in_8(&iic->xfrcnt),
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 in_8(&iic->xtcntlss), in_8(&iic->directcntl));
95}
96# define DUMP_REGS(h,dev) dump_iic_regs((h),(dev))
97#else
98# define DUMP_REGS(h,dev) ((void)0)
99#endif
100
101/* Bus timings (in ns) for bit-banging */
102static struct i2c_timings {
103 unsigned int hd_sta;
104 unsigned int su_sto;
105 unsigned int low;
106 unsigned int high;
107 unsigned int buf;
108} timings [] = {
109/* Standard mode (100 KHz) */
110{
111 .hd_sta = 4000,
112 .su_sto = 4000,
113 .low = 4700,
114 .high = 4000,
115 .buf = 4700,
116},
117/* Fast mode (400 KHz) */
118{
119 .hd_sta = 600,
120 .su_sto = 600,
121 .low = 1300,
122 .high = 600,
123 .buf = 1300,
124}};
125
126/* Enable/disable interrupt generation */
127static inline void iic_interrupt_mode(struct ibm_iic_private* dev, int enable)
128{
129 out_8(&dev->vaddr->intmsk, enable ? INTRMSK_EIMTC : 0);
130}
Stefan Roese217bcec2008-01-27 18:14:45 +0100131
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132/*
133 * Initialize IIC interface.
134 */
135static void iic_dev_init(struct ibm_iic_private* dev)
136{
137 volatile struct iic_regs __iomem *iic = dev->vaddr;
138
139 DBG("%d: init\n", dev->idx);
Stefan Roese217bcec2008-01-27 18:14:45 +0100140
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 /* Clear master address */
142 out_8(&iic->lmadr, 0);
143 out_8(&iic->hmadr, 0);
144
145 /* Clear slave address */
146 out_8(&iic->lsadr, 0);
147 out_8(&iic->hsadr, 0);
148
149 /* Clear status & extended status */
150 out_8(&iic->sts, STS_SCMP | STS_IRQA);
151 out_8(&iic->extsts, EXTSTS_IRQP | EXTSTS_IRQD | EXTSTS_LA
152 | EXTSTS_ICT | EXTSTS_XFRA);
153
154 /* Set clock divider */
155 out_8(&iic->clkdiv, dev->clckdiv);
156
157 /* Clear transfer count */
158 out_8(&iic->xfrcnt, 0);
159
160 /* Clear extended control and status */
161 out_8(&iic->xtcntlss, XTCNTLSS_SRC | XTCNTLSS_SRS | XTCNTLSS_SWC
162 | XTCNTLSS_SWS);
163
164 /* Clear control register */
165 out_8(&iic->cntl, 0);
Stefan Roese217bcec2008-01-27 18:14:45 +0100166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 /* Enable interrupts if possible */
168 iic_interrupt_mode(dev, dev->irq >= 0);
169
170 /* Set mode control */
171 out_8(&iic->mdcntl, MDCNTL_FMDB | MDCNTL_EINT | MDCNTL_EUBS
172 | (dev->fast_mode ? MDCNTL_FSM : 0));
173
174 DUMP_REGS("iic_init", dev);
175}
176
Stefan Roese217bcec2008-01-27 18:14:45 +0100177/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 * Reset IIC interface
179 */
180static void iic_dev_reset(struct ibm_iic_private* dev)
181{
182 volatile struct iic_regs __iomem *iic = dev->vaddr;
183 int i;
184 u8 dc;
Stefan Roese217bcec2008-01-27 18:14:45 +0100185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 DBG("%d: soft reset\n", dev->idx);
187 DUMP_REGS("reset", dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 /* Place chip in the reset state */
190 out_8(&iic->xtcntlss, XTCNTLSS_SRST);
Stefan Roese217bcec2008-01-27 18:14:45 +0100191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 /* Check if bus is free */
Stefan Roese217bcec2008-01-27 18:14:45 +0100193 dc = in_8(&iic->directcntl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 if (!DIRCTNL_FREE(dc)){
195 DBG("%d: trying to regain bus control\n", dev->idx);
Stefan Roese217bcec2008-01-27 18:14:45 +0100196
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 /* Try to set bus free state */
Stefan Roese217bcec2008-01-27 18:14:45 +0100198 out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
199
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 /* Wait until we regain bus control */
201 for (i = 0; i < 100; ++i){
202 dc = in_8(&iic->directcntl);
203 if (DIRCTNL_FREE(dc))
204 break;
Stefan Roese217bcec2008-01-27 18:14:45 +0100205
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 /* Toggle SCL line */
207 dc ^= DIRCNTL_SCC;
208 out_8(&iic->directcntl, dc);
209 udelay(10);
210 dc ^= DIRCNTL_SCC;
211 out_8(&iic->directcntl, dc);
Stefan Roese217bcec2008-01-27 18:14:45 +0100212
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 /* be nice */
214 cond_resched();
215 }
216 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 /* Remove reset */
219 out_8(&iic->xtcntlss, 0);
Stefan Roese217bcec2008-01-27 18:14:45 +0100220
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 /* Reinitialize interface */
222 iic_dev_init(dev);
223}
224
225/*
226 * Do 0-length transaction using bit-banging through IIC_DIRECTCNTL register.
227 */
228
229/* Wait for SCL and/or SDA to be high */
230static int iic_dc_wait(volatile struct iic_regs __iomem *iic, u8 mask)
231{
232 unsigned long x = jiffies + HZ / 28 + 2;
233 while ((in_8(&iic->directcntl) & mask) != mask){
234 if (unlikely(time_after(jiffies, x)))
235 return -1;
236 cond_resched();
237 }
238 return 0;
239}
240
241static int iic_smbus_quick(struct ibm_iic_private* dev, const struct i2c_msg* p)
242{
243 volatile struct iic_regs __iomem *iic = dev->vaddr;
244 const struct i2c_timings* t = &timings[dev->fast_mode ? 1 : 0];
245 u8 mask, v, sda;
246 int i, res;
247
248 /* Only 7-bit addresses are supported */
249 if (unlikely(p->flags & I2C_M_TEN)){
250 DBG("%d: smbus_quick - 10 bit addresses are not supported\n",
251 dev->idx);
252 return -EINVAL;
253 }
254
255 DBG("%d: smbus_quick(0x%02x)\n", dev->idx, p->addr);
256
257 /* Reset IIC interface */
258 out_8(&iic->xtcntlss, XTCNTLSS_SRST);
259
260 /* Wait for bus to become free */
261 out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
262 if (unlikely(iic_dc_wait(iic, DIRCNTL_MSDA | DIRCNTL_MSC)))
263 goto err;
264 ndelay(t->buf);
265
266 /* START */
267 out_8(&iic->directcntl, DIRCNTL_SCC);
268 sda = 0;
269 ndelay(t->hd_sta);
270
271 /* Send address */
272 v = (u8)((p->addr << 1) | ((p->flags & I2C_M_RD) ? 1 : 0));
273 for (i = 0, mask = 0x80; i < 8; ++i, mask >>= 1){
274 out_8(&iic->directcntl, sda);
275 ndelay(t->low / 2);
276 sda = (v & mask) ? DIRCNTL_SDAC : 0;
277 out_8(&iic->directcntl, sda);
278 ndelay(t->low / 2);
279
280 out_8(&iic->directcntl, DIRCNTL_SCC | sda);
281 if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
282 goto err;
283 ndelay(t->high);
284 }
285
286 /* ACK */
287 out_8(&iic->directcntl, sda);
288 ndelay(t->low / 2);
289 out_8(&iic->directcntl, DIRCNTL_SDAC);
290 ndelay(t->low / 2);
291 out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
292 if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
293 goto err;
294 res = (in_8(&iic->directcntl) & DIRCNTL_MSDA) ? -EREMOTEIO : 1;
295 ndelay(t->high);
296
297 /* STOP */
298 out_8(&iic->directcntl, 0);
299 ndelay(t->low);
300 out_8(&iic->directcntl, DIRCNTL_SCC);
301 if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
302 goto err;
303 ndelay(t->su_sto);
304 out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
305
306 ndelay(t->buf);
307
308 DBG("%d: smbus_quick -> %s\n", dev->idx, res ? "NACK" : "ACK");
309out:
310 /* Remove reset */
311 out_8(&iic->xtcntlss, 0);
312
313 /* Reinitialize interface */
314 iic_dev_init(dev);
315
316 return res;
317err:
318 DBG("%d: smbus_quick - bus is stuck\n", dev->idx);
319 res = -EREMOTEIO;
320 goto out;
321}
322
323/*
324 * IIC interrupt handler
325 */
David Howells7d12e782006-10-05 14:55:46 +0100326static irqreturn_t iic_handler(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327{
328 struct ibm_iic_private* dev = (struct ibm_iic_private*)dev_id;
329 volatile struct iic_regs __iomem *iic = dev->vaddr;
Stefan Roese217bcec2008-01-27 18:14:45 +0100330
331 DBG2("%d: irq handler, STS = 0x%02x, EXTSTS = 0x%02x\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 dev->idx, in_8(&iic->sts), in_8(&iic->extsts));
Stefan Roese217bcec2008-01-27 18:14:45 +0100333
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 /* Acknowledge IRQ and wakeup iic_wait_for_tc */
335 out_8(&iic->sts, STS_IRQA | STS_SCMP);
336 wake_up_interruptible(&dev->wq);
Stefan Roese217bcec2008-01-27 18:14:45 +0100337
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 return IRQ_HANDLED;
339}
340
341/*
342 * Get master transfer result and clear errors if any.
343 * Returns the number of actually transferred bytes or error (<0)
344 */
345static int iic_xfer_result(struct ibm_iic_private* dev)
346{
Stefan Roese217bcec2008-01-27 18:14:45 +0100347 volatile struct iic_regs __iomem *iic = dev->vaddr;
348
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 if (unlikely(in_8(&iic->sts) & STS_ERR)){
Stefan Roese217bcec2008-01-27 18:14:45 +0100350 DBG("%d: xfer error, EXTSTS = 0x%02x\n", dev->idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 in_8(&iic->extsts));
Stefan Roese217bcec2008-01-27 18:14:45 +0100352
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 /* Clear errors and possible pending IRQs */
Stefan Roese217bcec2008-01-27 18:14:45 +0100354 out_8(&iic->extsts, EXTSTS_IRQP | EXTSTS_IRQD |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 EXTSTS_LA | EXTSTS_ICT | EXTSTS_XFRA);
Stefan Roese217bcec2008-01-27 18:14:45 +0100356
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 /* Flush master data buffer */
358 out_8(&iic->mdcntl, in_8(&iic->mdcntl) | MDCNTL_FMDB);
Stefan Roese217bcec2008-01-27 18:14:45 +0100359
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 /* Is bus free?
361 * If error happened during combined xfer
362 * IIC interface is usually stuck in some strange
363 * state, the only way out - soft reset.
364 */
365 if ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){
366 DBG("%d: bus is stuck, resetting\n", dev->idx);
367 iic_dev_reset(dev);
368 }
369 return -EREMOTEIO;
370 }
371 else
372 return in_8(&iic->xfrcnt) & XFRCNT_MTC_MASK;
373}
374
375/*
376 * Try to abort active transfer.
377 */
378static void iic_abort_xfer(struct ibm_iic_private* dev)
379{
380 volatile struct iic_regs __iomem *iic = dev->vaddr;
381 unsigned long x;
Stefan Roese217bcec2008-01-27 18:14:45 +0100382
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 DBG("%d: iic_abort_xfer\n", dev->idx);
Stefan Roese217bcec2008-01-27 18:14:45 +0100384
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 out_8(&iic->cntl, CNTL_HMT);
Stefan Roese217bcec2008-01-27 18:14:45 +0100386
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 /*
388 * Wait for the abort command to complete.
389 * It's not worth to be optimized, just poll (timeout >= 1 tick)
390 */
391 x = jiffies + 2;
392 while ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){
393 if (time_after(jiffies, x)){
394 DBG("%d: abort timeout, resetting...\n", dev->idx);
395 iic_dev_reset(dev);
396 return;
397 }
398 schedule();
399 }
400
401 /* Just to clear errors */
402 iic_xfer_result(dev);
403}
404
405/*
406 * Wait for master transfer to complete.
407 * It puts current process to sleep until we get interrupt or timeout expires.
408 * Returns the number of transferred bytes or error (<0)
409 */
410static int iic_wait_for_tc(struct ibm_iic_private* dev){
Stefan Roese217bcec2008-01-27 18:14:45 +0100411
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 volatile struct iic_regs __iomem *iic = dev->vaddr;
413 int ret = 0;
Stefan Roese217bcec2008-01-27 18:14:45 +0100414
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 if (dev->irq >= 0){
416 /* Interrupt mode */
Stefan Roese217bcec2008-01-27 18:14:45 +0100417 ret = wait_event_interruptible_timeout(dev->wq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 !(in_8(&iic->sts) & STS_PT), dev->adap.timeout * HZ);
419
420 if (unlikely(ret < 0))
421 DBG("%d: wait interrupted\n", dev->idx);
422 else if (unlikely(in_8(&iic->sts) & STS_PT)){
423 DBG("%d: wait timeout\n", dev->idx);
424 ret = -ETIMEDOUT;
425 }
426 }
427 else {
428 /* Polling mode */
429 unsigned long x = jiffies + dev->adap.timeout * HZ;
Stefan Roese217bcec2008-01-27 18:14:45 +0100430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 while (in_8(&iic->sts) & STS_PT){
432 if (unlikely(time_after(jiffies, x))){
433 DBG("%d: poll timeout\n", dev->idx);
434 ret = -ETIMEDOUT;
435 break;
436 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 if (unlikely(signal_pending(current))){
439 DBG("%d: poll interrupted\n", dev->idx);
440 ret = -ERESTARTSYS;
441 break;
442 }
443 schedule();
Stefan Roese217bcec2008-01-27 18:14:45 +0100444 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100446
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 if (unlikely(ret < 0))
448 iic_abort_xfer(dev);
449 else
450 ret = iic_xfer_result(dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100451
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 DBG2("%d: iic_wait_for_tc -> %d\n", dev->idx, ret);
Stefan Roese217bcec2008-01-27 18:14:45 +0100453
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 return ret;
455}
456
457/*
458 * Low level master transfer routine
459 */
Stefan Roese217bcec2008-01-27 18:14:45 +0100460static int iic_xfer_bytes(struct ibm_iic_private* dev, struct i2c_msg* pm,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 int combined_xfer)
462{
463 volatile struct iic_regs __iomem *iic = dev->vaddr;
464 char* buf = pm->buf;
465 int i, j, loops, ret = 0;
466 int len = pm->len;
467
468 u8 cntl = (in_8(&iic->cntl) & CNTL_AMD) | CNTL_PT;
469 if (pm->flags & I2C_M_RD)
470 cntl |= CNTL_RW;
Stefan Roese217bcec2008-01-27 18:14:45 +0100471
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 loops = (len + 3) / 4;
473 for (i = 0; i < loops; ++i, len -= 4){
474 int count = len > 4 ? 4 : len;
475 u8 cmd = cntl | ((count - 1) << CNTL_TCT_SHIFT);
Stefan Roese217bcec2008-01-27 18:14:45 +0100476
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 if (!(cntl & CNTL_RW))
478 for (j = 0; j < count; ++j)
479 out_8((void __iomem *)&iic->mdbuf, *buf++);
Stefan Roese217bcec2008-01-27 18:14:45 +0100480
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 if (i < loops - 1)
482 cmd |= CNTL_CHT;
483 else if (combined_xfer)
484 cmd |= CNTL_RPST;
Stefan Roese217bcec2008-01-27 18:14:45 +0100485
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 DBG2("%d: xfer_bytes, %d, CNTL = 0x%02x\n", dev->idx, count, cmd);
Stefan Roese217bcec2008-01-27 18:14:45 +0100487
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 /* Start transfer */
489 out_8(&iic->cntl, cmd);
Stefan Roese217bcec2008-01-27 18:14:45 +0100490
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 /* Wait for completion */
492 ret = iic_wait_for_tc(dev);
493
494 if (unlikely(ret < 0))
495 break;
496 else if (unlikely(ret != count)){
Stefan Roese217bcec2008-01-27 18:14:45 +0100497 DBG("%d: xfer_bytes, requested %d, transfered %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 dev->idx, count, ret);
Stefan Roese217bcec2008-01-27 18:14:45 +0100499
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 /* If it's not a last part of xfer, abort it */
501 if (combined_xfer || (i < loops - 1))
502 iic_abort_xfer(dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100503
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 ret = -EREMOTEIO;
Stefan Roese217bcec2008-01-27 18:14:45 +0100505 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100507
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 if (cntl & CNTL_RW)
509 for (j = 0; j < count; ++j)
510 *buf++ = in_8((void __iomem *)&iic->mdbuf);
511 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100512
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 return ret > 0 ? 0 : ret;
514}
515
516/*
517 * Set target slave address for master transfer
518 */
519static inline void iic_address(struct ibm_iic_private* dev, struct i2c_msg* msg)
520{
521 volatile struct iic_regs __iomem *iic = dev->vaddr;
522 u16 addr = msg->addr;
Stefan Roese217bcec2008-01-27 18:14:45 +0100523
524 DBG2("%d: iic_address, 0x%03x (%d-bit)\n", dev->idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 addr, msg->flags & I2C_M_TEN ? 10 : 7);
Stefan Roese217bcec2008-01-27 18:14:45 +0100526
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 if (msg->flags & I2C_M_TEN){
528 out_8(&iic->cntl, CNTL_AMD);
529 out_8(&iic->lmadr, addr);
530 out_8(&iic->hmadr, 0xf0 | ((addr >> 7) & 0x06));
531 }
532 else {
533 out_8(&iic->cntl, 0);
534 out_8(&iic->lmadr, addr << 1);
535 }
536}
537
538static inline int iic_invalid_address(const struct i2c_msg* p)
539{
540 return (p->addr > 0x3ff) || (!(p->flags & I2C_M_TEN) && (p->addr > 0x7f));
541}
542
Stefan Roese217bcec2008-01-27 18:14:45 +0100543static inline int iic_address_neq(const struct i2c_msg* p1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 const struct i2c_msg* p2)
545{
Stefan Roese217bcec2008-01-27 18:14:45 +0100546 return (p1->addr != p2->addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 || ((p1->flags & I2C_M_TEN) != (p2->flags & I2C_M_TEN));
Stefan Roese217bcec2008-01-27 18:14:45 +0100548}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549
550/*
Stefan Roese217bcec2008-01-27 18:14:45 +0100551 * Generic master transfer entrypoint.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 * Returns the number of processed messages or error (<0)
553 */
554static int iic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
555{
556 struct ibm_iic_private* dev = (struct ibm_iic_private*)(i2c_get_adapdata(adap));
557 volatile struct iic_regs __iomem *iic = dev->vaddr;
558 int i, ret = 0;
Stefan Roese217bcec2008-01-27 18:14:45 +0100559
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 DBG2("%d: iic_xfer, %d msg(s)\n", dev->idx, num);
Stefan Roese217bcec2008-01-27 18:14:45 +0100561
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 if (!num)
563 return 0;
Stefan Roese217bcec2008-01-27 18:14:45 +0100564
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 /* Check the sanity of the passed messages.
566 * Uhh, generic i2c layer is more suitable place for such code...
567 */
568 if (unlikely(iic_invalid_address(&msgs[0]))){
Stefan Roese217bcec2008-01-27 18:14:45 +0100569 DBG("%d: invalid address 0x%03x (%d-bit)\n", dev->idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 msgs[0].addr, msgs[0].flags & I2C_M_TEN ? 10 : 7);
571 return -EINVAL;
Stefan Roese217bcec2008-01-27 18:14:45 +0100572 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 for (i = 0; i < num; ++i){
574 if (unlikely(msgs[i].len <= 0)){
575 if (num == 1 && !msgs[0].len){
576 /* Special case for I2C_SMBUS_QUICK emulation.
577 * IBM IIC doesn't support 0-length transactions
578 * so we have to emulate them using bit-banging.
579 */
580 return iic_smbus_quick(dev, &msgs[0]);
581 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100582 DBG("%d: invalid len %d in msg[%d]\n", dev->idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 msgs[i].len, i);
584 return -EINVAL;
585 }
586 if (unlikely(iic_address_neq(&msgs[0], &msgs[i]))){
587 DBG("%d: invalid addr in msg[%d]\n", dev->idx, i);
588 return -EINVAL;
589 }
590 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100591
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 /* Check bus state */
593 if (unlikely((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE)){
594 DBG("%d: iic_xfer, bus is not free\n", dev->idx);
Stefan Roese217bcec2008-01-27 18:14:45 +0100595
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 /* Usually it means something serious has happend.
597 * We *cannot* have unfinished previous transfer
598 * so it doesn't make any sense to try to stop it.
Stefan Roese217bcec2008-01-27 18:14:45 +0100599 * Probably we were not able to recover from the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 * previous error.
601 * The only *reasonable* thing I can think of here
602 * is soft reset. --ebs
603 */
604 iic_dev_reset(dev);
Stefan Roese217bcec2008-01-27 18:14:45 +0100605
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 if ((in_8(&iic->extsts) & EXTSTS_BCS_MASK) != EXTSTS_BCS_FREE){
607 DBG("%d: iic_xfer, bus is still not free\n", dev->idx);
608 return -EREMOTEIO;
609 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100610 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 else {
612 /* Flush master data buffer (just in case) */
613 out_8(&iic->mdcntl, in_8(&iic->mdcntl) | MDCNTL_FMDB);
614 }
Stefan Roese217bcec2008-01-27 18:14:45 +0100615
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 /* Load slave address */
617 iic_address(dev, &msgs[0]);
Stefan Roese217bcec2008-01-27 18:14:45 +0100618
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 /* Do real transfer */
620 for (i = 0; i < num && !ret; ++i)
621 ret = iic_xfer_bytes(dev, &msgs[i], i < num - 1);
622
623 return ret < 0 ? ret : num;
624}
625
626static u32 iic_func(struct i2c_adapter *adap)
627{
628 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
629}
630
Jean Delvare8f9082c2006-09-03 22:39:46 +0200631static const struct i2c_algorithm iic_algo = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 .master_xfer = iic_xfer,
633 .functionality = iic_func
634};
635
636/*
637 * Calculates IICx_CLCKDIV value for a specific OPB clock frequency
638 */
639static inline u8 iic_clckdiv(unsigned int opb)
640{
641 /* Compatibility kludge, should go away after all cards
642 * are fixed to fill correct value for opbfreq.
643 * Previous driver version used hardcoded divider value 4,
644 * it corresponds to OPB frequency from the range (40, 50] MHz
645 */
646 if (!opb){
647 printk(KERN_WARNING "ibm-iic: using compatibility value for OPB freq,"
648 " fix your board specific setup\n");
649 opb = 50000000;
650 }
651
652 /* Convert to MHz */
653 opb /= 1000000;
Stefan Roese217bcec2008-01-27 18:14:45 +0100654
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 if (opb < 20 || opb > 150){
Sean MacLennan681aae82008-04-22 22:16:46 +0200656 printk(KERN_WARNING "ibm-iic: invalid OPB clock frequency %u MHz\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 opb);
658 opb = opb < 20 ? 20 : 150;
659 }
660 return (u8)((opb + 9) / 10 - 1);
661}
662
Sean MacLennan838349b2008-04-22 22:16:47 +0200663static int __devinit iic_request_irq(struct of_device *ofdev,
664 struct ibm_iic_private *dev)
665{
666 struct device_node *np = ofdev->node;
667 int irq;
668
669 if (iic_force_poll)
670 return NO_IRQ;
671
672 irq = irq_of_parse_and_map(np, 0);
673 if (irq == NO_IRQ) {
674 dev_err(&ofdev->dev, "irq_of_parse_and_map failed\n");
675 return NO_IRQ;
676 }
677
678 /* Disable interrupts until we finish initialization, assumes
679 * level-sensitive IRQ setup...
680 */
681 iic_interrupt_mode(dev, 0);
682 if (request_irq(irq, iic_handler, 0, "IBM IIC", dev)) {
683 dev_err(&ofdev->dev, "request_irq %d failed\n", irq);
684 /* Fallback to the polling mode */
685 return NO_IRQ;
686 }
687
688 return irq;
689}
690
691/*
692 * Register single IIC interface
693 */
694static int __devinit iic_probe(struct of_device *ofdev,
695 const struct of_device_id *match)
696{
697 struct device_node *np = ofdev->node;
698 struct ibm_iic_private *dev;
699 struct i2c_adapter *adap;
Sean MacLennanb1204e62008-07-14 22:38:36 +0200700 const u32 *freq;
Sean MacLennan838349b2008-04-22 22:16:47 +0200701 int ret;
702
703 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
704 if (!dev) {
705 dev_err(&ofdev->dev, "failed to allocate device data\n");
706 return -ENOMEM;
707 }
708
709 dev_set_drvdata(&ofdev->dev, dev);
710
Sean MacLennan838349b2008-04-22 22:16:47 +0200711 dev->vaddr = of_iomap(np, 0);
712 if (dev->vaddr == NULL) {
713 dev_err(&ofdev->dev, "failed to iomap device\n");
714 ret = -ENXIO;
715 goto error_cleanup;
716 }
717
718 init_waitqueue_head(&dev->wq);
719
720 dev->irq = iic_request_irq(ofdev, dev);
721 if (dev->irq == NO_IRQ)
722 dev_warn(&ofdev->dev, "using polling mode\n");
723
724 /* Board specific settings */
725 if (iic_force_fast || of_get_property(np, "fast-mode", NULL))
726 dev->fast_mode = 1;
727
728 freq = of_get_property(np, "clock-frequency", NULL);
729 if (freq == NULL) {
730 freq = of_get_property(np->parent, "clock-frequency", NULL);
731 if (freq == NULL) {
732 dev_err(&ofdev->dev, "Unable to get bus frequency\n");
733 ret = -EINVAL;
734 goto error_cleanup;
735 }
736 }
737
738 dev->clckdiv = iic_clckdiv(*freq);
739 dev_dbg(&ofdev->dev, "clckdiv = %d\n", dev->clckdiv);
740
741 /* Initialize IIC interface */
742 iic_dev_init(dev);
743
744 /* Register it with i2c layer */
745 adap = &dev->adap;
746 adap->dev.parent = &ofdev->dev;
747 strlcpy(adap->name, "IBM IIC", sizeof(adap->name));
748 i2c_set_adapdata(adap, dev);
Jean Delvare3401b2f2008-07-14 22:38:29 +0200749 adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
Sean MacLennan838349b2008-04-22 22:16:47 +0200750 adap->algo = &iic_algo;
751 adap->timeout = 1;
Sean MacLennan838349b2008-04-22 22:16:47 +0200752
Sean MacLennanb1204e62008-07-14 22:38:36 +0200753 ret = i2c_add_adapter(adap);
Sean MacLennan838349b2008-04-22 22:16:47 +0200754 if (ret < 0) {
755 dev_err(&ofdev->dev, "failed to register i2c adapter\n");
756 goto error_cleanup;
757 }
758
Sean MacLennanb1204e62008-07-14 22:38:36 +0200759 /* Now register all the child nodes */
760 of_register_i2c_devices(adap, np);
761
Sean MacLennan838349b2008-04-22 22:16:47 +0200762 dev_info(&ofdev->dev, "using %s mode\n",
763 dev->fast_mode ? "fast (400 kHz)" : "standard (100 kHz)");
764
765 return 0;
766
767error_cleanup:
768 if (dev->irq != NO_IRQ) {
769 iic_interrupt_mode(dev, 0);
770 free_irq(dev->irq, dev);
771 }
772
773 if (dev->vaddr)
774 iounmap(dev->vaddr);
775
776 dev_set_drvdata(&ofdev->dev, NULL);
777 kfree(dev);
778 return ret;
779}
780
781/*
782 * Cleanup initialized IIC interface
783 */
784static int __devexit iic_remove(struct of_device *ofdev)
785{
786 struct ibm_iic_private *dev = dev_get_drvdata(&ofdev->dev);
787
788 dev_set_drvdata(&ofdev->dev, NULL);
789
790 i2c_del_adapter(&dev->adap);
791
792 if (dev->irq != NO_IRQ) {
793 iic_interrupt_mode(dev, 0);
794 free_irq(dev->irq, dev);
795 }
796
797 iounmap(dev->vaddr);
798 kfree(dev);
799
800 return 0;
801}
802
803static const struct of_device_id ibm_iic_match[] = {
Stefan Roesed3dc6852008-07-14 22:38:30 +0200804 { .compatible = "ibm,iic", },
Sean MacLennan838349b2008-04-22 22:16:47 +0200805 {}
806};
807
808static struct of_platform_driver ibm_iic_driver = {
809 .name = "ibm-iic",
810 .match_table = ibm_iic_match,
811 .probe = iic_probe,
812 .remove = __devexit_p(iic_remove),
813};
814
815static int __init iic_init(void)
816{
817 return of_register_platform_driver(&ibm_iic_driver);
818}
819
820static void __exit iic_exit(void)
821{
822 of_unregister_platform_driver(&ibm_iic_driver);
823}
Sean MacLennan838349b2008-04-22 22:16:47 +0200824
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825module_init(iic_init);
826module_exit(iic_exit);