?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[ARM] omap: i2c: remove conditional ick clocks
[linux-2.6/verdex.git] / drivers / i2c / busses / i2c-omap.c
blobece0125a1ee520710f1e4ac18cd7b8eea83f0422
1 /*
2 * TI OMAP I2C master mode driver
3 *
4 * Copyright (C) 2003 MontaVista Software, Inc.
5 * Copyright (C) 2005 Nokia Corporation
6 * Copyright (C) 2004 - 2007 Texas Instruments.
7 *
8 * Originally written by MontaVista Software, Inc.
9 * Additional contributions by:
10 * Tony Lindgren <tony@atomide.com>
11 * Imre Deak <imre.deak@nokia.com>
12 * Juha Yrjölä <juha.yrjola@solidboot.com>
13 * Syed Khasim <x0khasim@ti.com>
14 * Nishant Menon <nm@ti.com>
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
20 *
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 */
30
31 #include <linux/module.h>
32 #include <linux/delay.h>
33 #include <linux/i2c.h>
34 #include <linux/err.h>
35 #include <linux/interrupt.h>
36 #include <linux/completion.h>
37 #include <linux/platform_device.h>
38 #include <linux/clk.h>
39 #include <linux/io.h>
40
41 /* I2C controller revisions */
42 #define OMAP_I2C_REV_2 0x20
43
44 /* I2C controller revisions present on specific hardware */
45 #define OMAP_I2C_REV_ON_2430 0x36
46 #define OMAP_I2C_REV_ON_3430 0x3C
47
48 /* timeout waiting for the controller to respond */
49 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
50
51 #define OMAP_I2C_REV_REG 0x00
52 #define OMAP_I2C_IE_REG 0x04
53 #define OMAP_I2C_STAT_REG 0x08
54 #define OMAP_I2C_IV_REG 0x0c
55 /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
56 #define OMAP_I2C_WE_REG 0x0c
57 #define OMAP_I2C_SYSS_REG 0x10
58 #define OMAP_I2C_BUF_REG 0x14
59 #define OMAP_I2C_CNT_REG 0x18
60 #define OMAP_I2C_DATA_REG 0x1c
61 #define OMAP_I2C_SYSC_REG 0x20
62 #define OMAP_I2C_CON_REG 0x24
63 #define OMAP_I2C_OA_REG 0x28
64 #define OMAP_I2C_SA_REG 0x2c
65 #define OMAP_I2C_PSC_REG 0x30
66 #define OMAP_I2C_SCLL_REG 0x34
67 #define OMAP_I2C_SCLH_REG 0x38
68 #define OMAP_I2C_SYSTEST_REG 0x3c
69 #define OMAP_I2C_BUFSTAT_REG 0x40
70
71 /* I2C Interrupt Enable Register (OMAP_I2C_IE): */
72 #define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */
73 #define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer drain int enable */
74 #define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */
75 #define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */
76 #define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */
77 #define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */
78 #define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */
79
80 /* I2C Status Register (OMAP_I2C_STAT): */
81 #define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */
82 #define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */
83 #define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */
84 #define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */
85 #define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */
86 #define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */
87 #define OMAP_I2C_STAT_AD0 (1 << 8) /* Address zero */
88 #define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */
89 #define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */
90 #define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */
91 #define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */
92 #define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */
93
94 /* I2C WE wakeup enable register */
95 #define OMAP_I2C_WE_XDR_WE (1 << 14) /* TX drain wakup */
96 #define OMAP_I2C_WE_RDR_WE (1 << 13) /* RX drain wakeup */
97 #define OMAP_I2C_WE_AAS_WE (1 << 9) /* Address as slave wakeup*/
98 #define OMAP_I2C_WE_BF_WE (1 << 8) /* Bus free wakeup */
99 #define OMAP_I2C_WE_STC_WE (1 << 6) /* Start condition wakeup */
100 #define OMAP_I2C_WE_GC_WE (1 << 5) /* General call wakeup */
101 #define OMAP_I2C_WE_DRDY_WE (1 << 3) /* TX/RX data ready wakeup */
102 #define OMAP_I2C_WE_ARDY_WE (1 << 2) /* Reg access ready wakeup */
103 #define OMAP_I2C_WE_NACK_WE (1 << 1) /* No acknowledgment wakeup */
104 #define OMAP_I2C_WE_AL_WE (1 << 0) /* Arbitration lost wakeup */
105
106 #define OMAP_I2C_WE_ALL (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
107 OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
108 OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
109 OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
110 OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
111
112 /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
113 #define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */
114 #define OMAP_I2C_BUF_RXFIF_CLR (1 << 14) /* RX FIFO Clear */
115 #define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */
116 #define OMAP_I2C_BUF_TXFIF_CLR (1 << 6) /* TX FIFO Clear */
117
118 /* I2C Configuration Register (OMAP_I2C_CON): */
119 #define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */
120 #define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */
121 #define OMAP_I2C_CON_OPMODE_HS (1 << 12) /* High Speed support */
122 #define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */
123 #define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */
124 #define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */
125 #define OMAP_I2C_CON_XA (1 << 8) /* Expand address */
126 #define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */
127 #define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */
128 #define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */
129
130 /* I2C SCL time value when Master */
131 #define OMAP_I2C_SCLL_HSSCLL 8
132 #define OMAP_I2C_SCLH_HSSCLH 8
133
134 /* I2C System Test Register (OMAP_I2C_SYSTEST): */
135 #ifdef DEBUG
136 #define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */
137 #define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */
138 #define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */
139 #define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */
140 #define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */
141 #define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */
142 #define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */
143 #define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */
144 #endif
145
146 /* OCP_SYSSTATUS bit definitions */
147 #define SYSS_RESETDONE_MASK (1 << 0)
148
149 /* OCP_SYSCONFIG bit definitions */
150 #define SYSC_CLOCKACTIVITY_MASK (0x3 << 8)
151 #define SYSC_SIDLEMODE_MASK (0x3 << 3)
152 #define SYSC_ENAWAKEUP_MASK (1 << 2)
153 #define SYSC_SOFTRESET_MASK (1 << 1)
154 #define SYSC_AUTOIDLE_MASK (1 << 0)
155
156 #define SYSC_IDLEMODE_SMART 0x2
157 #define SYSC_CLOCKACTIVITY_FCLK 0x2
158
159
160 struct omap_i2c_dev {
161 struct device *dev;
162 void __iomem *base; /* virtual */
163 int irq;
164 struct clk *iclk; /* Interface clock */
165 struct clk *fclk; /* Functional clock */
166 struct completion cmd_complete;
167 struct resource *ioarea;
168 u32 speed; /* Speed of bus in Khz */
169 u16 cmd_err;
170 u8 *buf;
171 size_t buf_len;
172 struct i2c_adapter adapter;
173 u8 fifo_size; /* use as flag and value
174 * fifo_size==0 implies no fifo
175 * if set, should be trsh+1
176 */
177 u8 rev;
178 unsigned b_hw:1; /* bad h/w fixes */
179 unsigned idle:1;
180 u16 iestate; /* Saved interrupt register */
181 };
182
183 static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
184 int reg, u16 val)
185 {
186 __raw_writew(val, i2c_dev->base + reg);
187 }
188
189 static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
190 {
191 return __raw_readw(i2c_dev->base + reg);
192 }
193
194 static int __init omap_i2c_get_clocks(struct omap_i2c_dev *dev)
195 {
196 int ret;
197
198 dev->iclk = clk_get(dev->dev, "ick");
199 if (IS_ERR(dev->iclk)) {
200 ret = PTR_ERR(dev->iclk);
201 dev->iclk = NULL;
202 return ret;
203 }
204
205 dev->fclk = clk_get(dev->dev, "fck");
206 if (IS_ERR(dev->fclk)) {
207 ret = PTR_ERR(dev->fclk);
208 if (dev->iclk != NULL) {
209 clk_put(dev->iclk);
210 dev->iclk = NULL;
211 }
212 dev->fclk = NULL;
213 return ret;
214 }
215
216 return 0;
217 }
218
219 static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
220 {
221 clk_put(dev->fclk);
222 dev->fclk = NULL;
223 clk_put(dev->iclk);
224 dev->iclk = NULL;
225 }
226
227 static void omap_i2c_unidle(struct omap_i2c_dev *dev)
228 {
229 WARN_ON(!dev->idle);
230
231 clk_enable(dev->iclk);
232 clk_enable(dev->fclk);
233 dev->idle = 0;
234 if (dev->iestate)
235 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
236 }
237
238 static void omap_i2c_idle(struct omap_i2c_dev *dev)
239 {
240 u16 iv;
241
242 WARN_ON(dev->idle);
243
244 dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
245 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
246 if (dev->rev < OMAP_I2C_REV_2) {
247 iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); /* Read clears */
248 } else {
249 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate);
250
251 /* Flush posted write before the dev->idle store occurs */
252 omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
253 }
254 dev->idle = 1;
255 clk_disable(dev->fclk);
256 clk_disable(dev->iclk);
257 }
258
259 static int omap_i2c_init(struct omap_i2c_dev *dev)
260 {
261 u16 psc = 0, scll = 0, sclh = 0;
262 u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
263 unsigned long fclk_rate = 12000000;
264 unsigned long timeout;
265 unsigned long internal_clk = 0;
266
267 if (dev->rev >= OMAP_I2C_REV_2) {
268 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
269 /* For some reason we need to set the EN bit before the
270 * reset done bit gets set. */
271 timeout = jiffies + OMAP_I2C_TIMEOUT;
272 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
273 while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
274 SYSS_RESETDONE_MASK)) {
275 if (time_after(jiffies, timeout)) {
276 dev_warn(dev->dev, "timeout waiting "
277 "for controller reset\n");
278 return -ETIMEDOUT;
279 }
280 msleep(1);
281 }
282
283 /* SYSC register is cleared by the reset; rewrite it */
284 if (dev->rev == OMAP_I2C_REV_ON_2430) {
285
286 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
287 SYSC_AUTOIDLE_MASK);
288
289 } else if (dev->rev >= OMAP_I2C_REV_ON_3430) {
290 u32 v;
291
292 v = SYSC_AUTOIDLE_MASK;
293 v |= SYSC_ENAWAKEUP_MASK;
294 v |= (SYSC_IDLEMODE_SMART <<
295 __ffs(SYSC_SIDLEMODE_MASK));
296 v |= (SYSC_CLOCKACTIVITY_FCLK <<
297 __ffs(SYSC_CLOCKACTIVITY_MASK));
298
299 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, v);
300 /*
301 * Enabling all wakup sources to stop I2C freezing on
302 * WFI instruction.
303 * REVISIT: Some wkup sources might not be needed.
304 */
305 omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
306 OMAP_I2C_WE_ALL);
307
308 }
309 }
310 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
311
312 if (cpu_class_is_omap1()) {
313 /*
314 * The I2C functional clock is the armxor_ck, so there's
315 * no need to get "armxor_ck" separately. Now, if OMAP2420
316 * always returns 12MHz for the functional clock, we can
317 * do this bit unconditionally.
318 */
319 fclk_rate = clk_get_rate(dev->fclk);
320
321 /* TRM for 5912 says the I2C clock must be prescaled to be
322 * between 7 - 12 MHz. The XOR input clock is typically
323 * 12, 13 or 19.2 MHz. So we should have code that produces:
324 *
325 * XOR MHz Divider Prescaler
326 * 12 1 0
327 * 13 2 1
328 * 19.2 2 1
329 */
330 if (fclk_rate > 12000000)
331 psc = fclk_rate / 12000000;
332 }
333
334 if (cpu_is_omap2430() || cpu_is_omap34xx()) {
335
336 /* HSI2C controller internal clk rate should be 19.2 Mhz */
337 internal_clk = 19200;
338 fclk_rate = clk_get_rate(dev->fclk) / 1000;
339
340 /* Compute prescaler divisor */
341 psc = fclk_rate / internal_clk;
342 psc = psc - 1;
343
344 /* If configured for High Speed */
345 if (dev->speed > 400) {
346 /* For first phase of HS mode */
347 fsscll = internal_clk / (400 * 2) - 6;
348 fssclh = internal_clk / (400 * 2) - 6;
349
350 /* For second phase of HS mode */
351 hsscll = fclk_rate / (dev->speed * 2) - 6;
352 hssclh = fclk_rate / (dev->speed * 2) - 6;
353 } else {
354 /* To handle F/S modes */
355 fsscll = internal_clk / (dev->speed * 2) - 6;
356 fssclh = internal_clk / (dev->speed * 2) - 6;
357 }
358 scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
359 sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
360 } else {
361 /* Program desired operating rate */
362 fclk_rate /= (psc + 1) * 1000;
363 if (psc > 2)
364 psc = 2;
365 scll = fclk_rate / (dev->speed * 2) - 7 + psc;
366 sclh = fclk_rate / (dev->speed * 2) - 7 + psc;
367 }
368
369 /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
370 omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
371
372 /* SCL low and high time values */
373 omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
374 omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
375
376 if (dev->fifo_size)
377 /* Note: setup required fifo size - 1 */
378 omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG,
379 (dev->fifo_size - 1) << 8 | /* RTRSH */
380 OMAP_I2C_BUF_RXFIF_CLR |
381 (dev->fifo_size - 1) | /* XTRSH */
382 OMAP_I2C_BUF_TXFIF_CLR);
383
384 /* Take the I2C module out of reset: */
385 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
386
387 /* Enable interrupts */
388 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
389 (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
390 OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
391 OMAP_I2C_IE_AL) | ((dev->fifo_size) ?
392 (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0));
393 return 0;
394 }
395
396 /*
397 * Waiting on Bus Busy
398 */
399 static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
400 {
401 unsigned long timeout;
402
403 timeout = jiffies + OMAP_I2C_TIMEOUT;
404 while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
405 if (time_after(jiffies, timeout)) {
406 dev_warn(dev->dev, "timeout waiting for bus ready\n");
407 return -ETIMEDOUT;
408 }
409 msleep(1);
410 }
411
412 return 0;
413 }
414
415 /*
416 * Low level master read/write transaction.
417 */
418 static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
419 struct i2c_msg *msg, int stop)
420 {
421 struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
422 int r;
423 u16 w;
424
425 dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
426 msg->addr, msg->len, msg->flags, stop);
427
428 if (msg->len == 0)
429 return -EINVAL;
430
431 omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
432
433 /* REVISIT: Could the STB bit of I2C_CON be used with probing? */
434 dev->buf = msg->buf;
435 dev->buf_len = msg->len;
436
437 omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
438
439 /* Clear the FIFO Buffers */
440 w = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
441 w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
442 omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, w);
443
444 init_completion(&dev->cmd_complete);
445 dev->cmd_err = 0;
446
447 w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
448
449 /* High speed configuration */
450 if (dev->speed > 400)
451 w |= OMAP_I2C_CON_OPMODE_HS;
452
453 if (msg->flags & I2C_M_TEN)
454 w |= OMAP_I2C_CON_XA;
455 if (!(msg->flags & I2C_M_RD))
456 w |= OMAP_I2C_CON_TRX;
457
458 if (!dev->b_hw && stop)
459 w |= OMAP_I2C_CON_STP;
460
461 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
462
463 /*
464 * Don't write stt and stp together on some hardware.
465 */
466 if (dev->b_hw && stop) {
467 unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
468 u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
469 while (con & OMAP_I2C_CON_STT) {
470 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
471
472 /* Let the user know if i2c is in a bad state */
473 if (time_after(jiffies, delay)) {
474 dev_err(dev->dev, "controller timed out "
475 "waiting for start condition to finish\n");
476 return -ETIMEDOUT;
477 }
478 cpu_relax();
479 }
480
481 w |= OMAP_I2C_CON_STP;
482 w &= ~OMAP_I2C_CON_STT;
483 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
484 }
485
486 /*
487 * REVISIT: We should abort the transfer on signals, but the bus goes
488 * into arbitration and we're currently unable to recover from it.
489 */
490 r = wait_for_completion_timeout(&dev->cmd_complete,
491 OMAP_I2C_TIMEOUT);
492 dev->buf_len = 0;
493 if (r < 0)
494 return r;
495 if (r == 0) {
496 dev_err(dev->dev, "controller timed out\n");
497 omap_i2c_init(dev);
498 return -ETIMEDOUT;
499 }
500
501 if (likely(!dev->cmd_err))
502 return 0;
503
504 /* We have an error */
505 if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
506 OMAP_I2C_STAT_XUDF)) {
507 omap_i2c_init(dev);
508 return -EIO;
509 }
510
511 if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
512 if (msg->flags & I2C_M_IGNORE_NAK)
513 return 0;
514 if (stop) {
515 w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
516 w |= OMAP_I2C_CON_STP;
517 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
518 }
519 return -EREMOTEIO;
520 }
521 return -EIO;
522 }
523
524
525 /*
526 * Prepare controller for a transaction and call omap_i2c_xfer_msg
527 * to do the work during IRQ processing.
528 */
529 static int
530 omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
531 {
532 struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
533 int i;
534 int r;
535
536 omap_i2c_unidle(dev);
537
538 r = omap_i2c_wait_for_bb(dev);
539 if (r < 0)
540 goto out;
541
542 for (i = 0; i < num; i++) {
543 r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
544 if (r != 0)
545 break;
546 }
547
548 if (r == 0)
549 r = num;
550 out:
551 omap_i2c_idle(dev);
552 return r;
553 }
554
555 static u32
556 omap_i2c_func(struct i2c_adapter *adap)
557 {
558 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
559 }
560
561 static inline void
562 omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
563 {
564 dev->cmd_err |= err;
565 complete(&dev->cmd_complete);
566 }
567
568 static inline void
569 omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
570 {
571 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
572 }
573
574 /* rev1 devices are apparently only on some 15xx */
575 #ifdef CONFIG_ARCH_OMAP15XX
576
577 static irqreturn_t
578 omap_i2c_rev1_isr(int this_irq, void *dev_id)
579 {
580 struct omap_i2c_dev *dev = dev_id;
581 u16 iv, w;
582
583 if (dev->idle)
584 return IRQ_NONE;
585
586 iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
587 switch (iv) {
588 case 0x00: /* None */
589 break;
590 case 0x01: /* Arbitration lost */
591 dev_err(dev->dev, "Arbitration lost\n");
592 omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
593 break;
594 case 0x02: /* No acknowledgement */
595 omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
596 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
597 break;
598 case 0x03: /* Register access ready */
599 omap_i2c_complete_cmd(dev, 0);
600 break;
601 case 0x04: /* Receive data ready */
602 if (dev->buf_len) {
603 w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
604 *dev->buf++ = w;
605 dev->buf_len--;
606 if (dev->buf_len) {
607 *dev->buf++ = w >> 8;
608 dev->buf_len--;
609 }
610 } else
611 dev_err(dev->dev, "RRDY IRQ while no data requested\n");
612 break;
613 case 0x05: /* Transmit data ready */
614 if (dev->buf_len) {
615 w = *dev->buf++;
616 dev->buf_len--;
617 if (dev->buf_len) {
618 w |= *dev->buf++ << 8;
619 dev->buf_len--;
620 }
621 omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
622 } else
623 dev_err(dev->dev, "XRDY IRQ while no data to send\n");
624 break;
625 default:
626 return IRQ_NONE;
627 }
628
629 return IRQ_HANDLED;
630 }
631 #else
632 #define omap_i2c_rev1_isr NULL
633 #endif
634
635 static irqreturn_t
636 omap_i2c_isr(int this_irq, void *dev_id)
637 {
638 struct omap_i2c_dev *dev = dev_id;
639 u16 bits;
640 u16 stat, w;
641 int err, count = 0;
642
643 if (dev->idle)
644 return IRQ_NONE;
645
646 bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
647 while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
648 dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
649 if (count++ == 100) {
650 dev_warn(dev->dev, "Too much work in one IRQ\n");
651 break;
652 }
653
654 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
655
656 err = 0;
657 if (stat & OMAP_I2C_STAT_NACK) {
658 err |= OMAP_I2C_STAT_NACK;
659 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
660 OMAP_I2C_CON_STP);
661 }
662 if (stat & OMAP_I2C_STAT_AL) {
663 dev_err(dev->dev, "Arbitration lost\n");
664 err |= OMAP_I2C_STAT_AL;
665 }
666 if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
667 OMAP_I2C_STAT_AL))
668 omap_i2c_complete_cmd(dev, err);
669 if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
670 u8 num_bytes = 1;
671 if (dev->fifo_size) {
672 if (stat & OMAP_I2C_STAT_RRDY)
673 num_bytes = dev->fifo_size;
674 else
675 num_bytes = omap_i2c_read_reg(dev,
676 OMAP_I2C_BUFSTAT_REG);
677 }
678 while (num_bytes) {
679 num_bytes--;
680 w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
681 if (dev->buf_len) {
682 *dev->buf++ = w;
683 dev->buf_len--;
684 /* Data reg from 2430 is 8 bit wide */
685 if (!cpu_is_omap2430() &&
686 !cpu_is_omap34xx()) {
687 if (dev->buf_len) {
688 *dev->buf++ = w >> 8;
689 dev->buf_len--;
690 }
691 }
692 } else {
693 if (stat & OMAP_I2C_STAT_RRDY)
694 dev_err(dev->dev,
695 "RRDY IRQ while no data"
696 " requested\n");
697 if (stat & OMAP_I2C_STAT_RDR)
698 dev_err(dev->dev,
699 "RDR IRQ while no data"
700 " requested\n");
701 break;
702 }
703 }
704 omap_i2c_ack_stat(dev,
705 stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
706 continue;
707 }
708 if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
709 u8 num_bytes = 1;
710 if (dev->fifo_size) {
711 if (stat & OMAP_I2C_STAT_XRDY)
712 num_bytes = dev->fifo_size;
713 else
714 num_bytes = omap_i2c_read_reg(dev,
715 OMAP_I2C_BUFSTAT_REG);
716 }
717 while (num_bytes) {
718 num_bytes--;
719 w = 0;
720 if (dev->buf_len) {
721 w = *dev->buf++;
722 dev->buf_len--;
723 /* Data reg from 2430 is 8 bit wide */
724 if (!cpu_is_omap2430() &&
725 !cpu_is_omap34xx()) {
726 if (dev->buf_len) {
727 w |= *dev->buf++ << 8;
728 dev->buf_len--;
729 }
730 }
731 } else {
732 if (stat & OMAP_I2C_STAT_XRDY)
733 dev_err(dev->dev,
734 "XRDY IRQ while no "
735 "data to send\n");
736 if (stat & OMAP_I2C_STAT_XDR)
737 dev_err(dev->dev,
738 "XDR IRQ while no "
739 "data to send\n");
740 break;
741 }
742 omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
743 }
744 omap_i2c_ack_stat(dev,
745 stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
746 continue;
747 }
748 if (stat & OMAP_I2C_STAT_ROVR) {
749 dev_err(dev->dev, "Receive overrun\n");
750 dev->cmd_err |= OMAP_I2C_STAT_ROVR;
751 }
752 if (stat & OMAP_I2C_STAT_XUDF) {
753 dev_err(dev->dev, "Transmit underflow\n");
754 dev->cmd_err |= OMAP_I2C_STAT_XUDF;
755 }
756 }
757
758 return count ? IRQ_HANDLED : IRQ_NONE;
759 }
760
761 static const struct i2c_algorithm omap_i2c_algo = {
762 .master_xfer = omap_i2c_xfer,
763 .functionality = omap_i2c_func,
764 };
765
766 static int __init
767 omap_i2c_probe(struct platform_device *pdev)
768 {
769 struct omap_i2c_dev *dev;
770 struct i2c_adapter *adap;
771 struct resource *mem, *irq, *ioarea;
772 irq_handler_t isr;
773 int r;
774 u32 speed = 0;
775
776 /* NOTE: driver uses the static register mapping */
777 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
778 if (!mem) {
779 dev_err(&pdev->dev, "no mem resource?\n");
780 return -ENODEV;
781 }
782 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
783 if (!irq) {
784 dev_err(&pdev->dev, "no irq resource?\n");
785 return -ENODEV;
786 }
787
788 ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
789 pdev->name);
790 if (!ioarea) {
791 dev_err(&pdev->dev, "I2C region already claimed\n");
792 return -EBUSY;
793 }
794
795 dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
796 if (!dev) {
797 r = -ENOMEM;
798 goto err_release_region;
799 }
800
801 if (pdev->dev.platform_data != NULL)
802 speed = *(u32 *)pdev->dev.platform_data;
803 else
804 speed = 100; /* Defualt speed */
805
806 dev->speed = speed;
807 dev->idle = 1;
808 dev->dev = &pdev->dev;
809 dev->irq = irq->start;
810 dev->base = ioremap(mem->start, mem->end - mem->start + 1);
811 if (!dev->base) {
812 r = -ENOMEM;
813 goto err_free_mem;
814 }
815
816 platform_set_drvdata(pdev, dev);
817
818 if ((r = omap_i2c_get_clocks(dev)) != 0)
819 goto err_iounmap;
820
821 omap_i2c_unidle(dev);
822
823 dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
824
825 if (cpu_is_omap2430() || cpu_is_omap34xx()) {
826 u16 s;
827
828 /* Set up the fifo size - Get total size */
829 s = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
830 dev->fifo_size = 0x8 << s;
831
832 /*
833 * Set up notification threshold as half the total available
834 * size. This is to ensure that we can handle the status on int
835 * call back latencies.
836 */
837 dev->fifo_size = (dev->fifo_size / 2);
838 dev->b_hw = 1; /* Enable hardware fixes */
839 }
840
841 /* reset ASAP, clearing any IRQs */
842 omap_i2c_init(dev);
843
844 isr = (dev->rev < OMAP_I2C_REV_2) ? omap_i2c_rev1_isr : omap_i2c_isr;
845 r = request_irq(dev->irq, isr, 0, pdev->name, dev);
846
847 if (r) {
848 dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
849 goto err_unuse_clocks;
850 }
851
852 dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n",
853 pdev->id, dev->rev >> 4, dev->rev & 0xf, dev->speed);
854
855 omap_i2c_idle(dev);
856
857 adap = &dev->adapter;
858 i2c_set_adapdata(adap, dev);
859 adap->owner = THIS_MODULE;
860 adap->class = I2C_CLASS_HWMON;
861 strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
862 adap->algo = &omap_i2c_algo;
863 adap->dev.parent = &pdev->dev;
864
865 /* i2c device drivers may be active on return from add_adapter() */
866 adap->nr = pdev->id;
867 r = i2c_add_numbered_adapter(adap);
868 if (r) {
869 dev_err(dev->dev, "failure adding adapter\n");
870 goto err_free_irq;
871 }
872
873 return 0;
874
875 err_free_irq:
876 free_irq(dev->irq, dev);
877 err_unuse_clocks:
878 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
879 omap_i2c_idle(dev);
880 omap_i2c_put_clocks(dev);
881 err_iounmap:
882 iounmap(dev->base);
883 err_free_mem:
884 platform_set_drvdata(pdev, NULL);
885 kfree(dev);
886 err_release_region:
887 release_mem_region(mem->start, (mem->end - mem->start) + 1);
888
889 return r;
890 }
891
892 static int
893 omap_i2c_remove(struct platform_device *pdev)
894 {
895 struct omap_i2c_dev *dev = platform_get_drvdata(pdev);
896 struct resource *mem;
897
898 platform_set_drvdata(pdev, NULL);
899
900 free_irq(dev->irq, dev);
901 i2c_del_adapter(&dev->adapter);
902 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
903 omap_i2c_put_clocks(dev);
904 iounmap(dev->base);
905 kfree(dev);
906 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
907 release_mem_region(mem->start, (mem->end - mem->start) + 1);
908 return 0;
909 }
910
911 static struct platform_driver omap_i2c_driver = {
912 .probe = omap_i2c_probe,
913 .remove = omap_i2c_remove,
914 .driver = {
915 .name = "i2c_omap",
916 .owner = THIS_MODULE,
917 },
918 };
919
920 /* I2C may be needed to bring up other drivers */
921 static int __init
922 omap_i2c_init_driver(void)
923 {
924 return platform_driver_register(&omap_i2c_driver);
925 }
926 subsys_initcall(omap_i2c_init_driver);
927
928 static void __exit omap_i2c_exit_driver(void)
929 {
930 platform_driver_unregister(&omap_i2c_driver);
931 }
932 module_exit(omap_i2c_exit_driver);
933
934 MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
935 MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
936 MODULE_LICENSE("GPL");
937 MODULE_ALIAS("platform:i2c_omap");
Verdex Pro support