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alpha: nautilus - fix hang on boot
[linux-2.6/mini2440.git] / drivers / i2c / busses / i2c-omap.c
blobbe8ee2cac8bbe237c459fcd497cef8812acea728
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 if (cpu_is_omap16xx() || cpu_class_is_omap2()) {
197 dev->iclk = clk_get(dev->dev, "i2c_ick");
198 if (IS_ERR(dev->iclk)) {
199 dev->iclk = NULL;
200 return -ENODEV;
201 }
202 }
203
204 dev->fclk = clk_get(dev->dev, "i2c_fck");
205 if (IS_ERR(dev->fclk)) {
206 if (dev->iclk != NULL) {
207 clk_put(dev->iclk);
208 dev->iclk = NULL;
209 }
210 dev->fclk = NULL;
211 return -ENODEV;
212 }
213
214 return 0;
215 }
216
217 static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
218 {
219 clk_put(dev->fclk);
220 dev->fclk = NULL;
221 if (dev->iclk != NULL) {
222 clk_put(dev->iclk);
223 dev->iclk = NULL;
224 }
225 }
226
227 static void omap_i2c_unidle(struct omap_i2c_dev *dev)
228 {
229 WARN_ON(!dev->idle);
230
231 if (dev->iclk != NULL)
232 clk_enable(dev->iclk);
233 clk_enable(dev->fclk);
234 dev->idle = 0;
235 if (dev->iestate)
236 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
237 }
238
239 static void omap_i2c_idle(struct omap_i2c_dev *dev)
240 {
241 u16 iv;
242
243 WARN_ON(dev->idle);
244
245 dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
246 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
247 if (dev->rev < OMAP_I2C_REV_2) {
248 iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); /* Read clears */
249 } else {
250 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate);
251
252 /* Flush posted write before the dev->idle store occurs */
253 omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
254 }
255 dev->idle = 1;
256 clk_disable(dev->fclk);
257 if (dev->iclk != NULL)
258 clk_disable(dev->iclk);
259 }
260
261 static int omap_i2c_init(struct omap_i2c_dev *dev)
262 {
263 u16 psc = 0, scll = 0, sclh = 0;
264 u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
265 unsigned long fclk_rate = 12000000;
266 unsigned long timeout;
267 unsigned long internal_clk = 0;
268
269 if (dev->rev >= OMAP_I2C_REV_2) {
270 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
271 /* For some reason we need to set the EN bit before the
272 * reset done bit gets set. */
273 timeout = jiffies + OMAP_I2C_TIMEOUT;
274 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
275 while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
276 SYSS_RESETDONE_MASK)) {
277 if (time_after(jiffies, timeout)) {
278 dev_warn(dev->dev, "timeout waiting "
279 "for controller reset\n");
280 return -ETIMEDOUT;
281 }
282 msleep(1);
283 }
284
285 /* SYSC register is cleared by the reset; rewrite it */
286 if (dev->rev == OMAP_I2C_REV_ON_2430) {
287
288 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
289 SYSC_AUTOIDLE_MASK);
290
291 } else if (dev->rev >= OMAP_I2C_REV_ON_3430) {
292 u32 v;
293
294 v = SYSC_AUTOIDLE_MASK;
295 v |= SYSC_ENAWAKEUP_MASK;
296 v |= (SYSC_IDLEMODE_SMART <<
297 __ffs(SYSC_SIDLEMODE_MASK));
298 v |= (SYSC_CLOCKACTIVITY_FCLK <<
299 __ffs(SYSC_CLOCKACTIVITY_MASK));
300
301 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, v);
302 /*
303 * Enabling all wakup sources to stop I2C freezing on
304 * WFI instruction.
305 * REVISIT: Some wkup sources might not be needed.
306 */
307 omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
308 OMAP_I2C_WE_ALL);
309
310 }
311 }
312 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
313
314 if (cpu_class_is_omap1()) {
315 struct clk *armxor_ck;
316
317 armxor_ck = clk_get(NULL, "armxor_ck");
318 if (IS_ERR(armxor_ck))
319 dev_warn(dev->dev, "Could not get armxor_ck\n");
320 else {
321 fclk_rate = clk_get_rate(armxor_ck);
322 clk_put(armxor_ck);
323 }
324 /* TRM for 5912 says the I2C clock must be prescaled to be
325 * between 7 - 12 MHz. The XOR input clock is typically
326 * 12, 13 or 19.2 MHz. So we should have code that produces:
327 *
328 * XOR MHz Divider Prescaler
329 * 12 1 0
330 * 13 2 1
331 * 19.2 2 1
332 */
333 if (fclk_rate > 12000000)
334 psc = fclk_rate / 12000000;
335 }
336
337 if (cpu_is_omap2430() || cpu_is_omap34xx()) {
338
339 /* HSI2C controller internal clk rate should be 19.2 Mhz */
340 internal_clk = 19200;
341 fclk_rate = clk_get_rate(dev->fclk) / 1000;
342
343 /* Compute prescaler divisor */
344 psc = fclk_rate / internal_clk;
345 psc = psc - 1;
346
347 /* If configured for High Speed */
348 if (dev->speed > 400) {
349 /* For first phase of HS mode */
350 fsscll = internal_clk / (400 * 2) - 6;
351 fssclh = internal_clk / (400 * 2) - 6;
352
353 /* For second phase of HS mode */
354 hsscll = fclk_rate / (dev->speed * 2) - 6;
355 hssclh = fclk_rate / (dev->speed * 2) - 6;
356 } else {
357 /* To handle F/S modes */
358 fsscll = internal_clk / (dev->speed * 2) - 6;
359 fssclh = internal_clk / (dev->speed * 2) - 6;
360 }
361 scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
362 sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
363 } else {
364 /* Program desired operating rate */
365 fclk_rate /= (psc + 1) * 1000;
366 if (psc > 2)
367 psc = 2;
368 scll = fclk_rate / (dev->speed * 2) - 7 + psc;
369 sclh = fclk_rate / (dev->speed * 2) - 7 + psc;
370 }
371
372 /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
373 omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
374
375 /* SCL low and high time values */
376 omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
377 omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
378
379 if (dev->fifo_size)
380 /* Note: setup required fifo size - 1 */
381 omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG,
382 (dev->fifo_size - 1) << 8 | /* RTRSH */
383 OMAP_I2C_BUF_RXFIF_CLR |
384 (dev->fifo_size - 1) | /* XTRSH */
385 OMAP_I2C_BUF_TXFIF_CLR);
386
387 /* Take the I2C module out of reset: */
388 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
389
390 /* Enable interrupts */
391 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
392 (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
393 OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
394 OMAP_I2C_IE_AL) | ((dev->fifo_size) ?
395 (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0));
396 return 0;
397 }
398
399 /*
400 * Waiting on Bus Busy
401 */
402 static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
403 {
404 unsigned long timeout;
405
406 timeout = jiffies + OMAP_I2C_TIMEOUT;
407 while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
408 if (time_after(jiffies, timeout)) {
409 dev_warn(dev->dev, "timeout waiting for bus ready\n");
410 return -ETIMEDOUT;
411 }
412 msleep(1);
413 }
414
415 return 0;
416 }
417
418 /*
419 * Low level master read/write transaction.
420 */
421 static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
422 struct i2c_msg *msg, int stop)
423 {
424 struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
425 int r;
426 u16 w;
427
428 dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
429 msg->addr, msg->len, msg->flags, stop);
430
431 if (msg->len == 0)
432 return -EINVAL;
433
434 omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
435
436 /* REVISIT: Could the STB bit of I2C_CON be used with probing? */
437 dev->buf = msg->buf;
438 dev->buf_len = msg->len;
439
440 omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
441
442 /* Clear the FIFO Buffers */
443 w = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
444 w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
445 omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, w);
446
447 init_completion(&dev->cmd_complete);
448 dev->cmd_err = 0;
449
450 w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
451
452 /* High speed configuration */
453 if (dev->speed > 400)
454 w |= OMAP_I2C_CON_OPMODE_HS;
455
456 if (msg->flags & I2C_M_TEN)
457 w |= OMAP_I2C_CON_XA;
458 if (!(msg->flags & I2C_M_RD))
459 w |= OMAP_I2C_CON_TRX;
460
461 if (!dev->b_hw && stop)
462 w |= OMAP_I2C_CON_STP;
463
464 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
465
466 /*
467 * Don't write stt and stp together on some hardware.
468 */
469 if (dev->b_hw && stop) {
470 unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
471 u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
472 while (con & OMAP_I2C_CON_STT) {
473 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
474
475 /* Let the user know if i2c is in a bad state */
476 if (time_after(jiffies, delay)) {
477 dev_err(dev->dev, "controller timed out "
478 "waiting for start condition to finish\n");
479 return -ETIMEDOUT;
480 }
481 cpu_relax();
482 }
483
484 w |= OMAP_I2C_CON_STP;
485 w &= ~OMAP_I2C_CON_STT;
486 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
487 }
488
489 /*
490 * REVISIT: We should abort the transfer on signals, but the bus goes
491 * into arbitration and we're currently unable to recover from it.
492 */
493 r = wait_for_completion_timeout(&dev->cmd_complete,
494 OMAP_I2C_TIMEOUT);
495 dev->buf_len = 0;
496 if (r < 0)
497 return r;
498 if (r == 0) {
499 dev_err(dev->dev, "controller timed out\n");
500 omap_i2c_init(dev);
501 return -ETIMEDOUT;
502 }
503
504 if (likely(!dev->cmd_err))
505 return 0;
506
507 /* We have an error */
508 if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
509 OMAP_I2C_STAT_XUDF)) {
510 omap_i2c_init(dev);
511 return -EIO;
512 }
513
514 if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
515 if (msg->flags & I2C_M_IGNORE_NAK)
516 return 0;
517 if (stop) {
518 w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
519 w |= OMAP_I2C_CON_STP;
520 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
521 }
522 return -EREMOTEIO;
523 }
524 return -EIO;
525 }
526
527
528 /*
529 * Prepare controller for a transaction and call omap_i2c_xfer_msg
530 * to do the work during IRQ processing.
531 */
532 static int
533 omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
534 {
535 struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
536 int i;
537 int r;
538
539 omap_i2c_unidle(dev);
540
541 r = omap_i2c_wait_for_bb(dev);
542 if (r < 0)
543 goto out;
544
545 for (i = 0; i < num; i++) {
546 r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
547 if (r != 0)
548 break;
549 }
550
551 if (r == 0)
552 r = num;
553 out:
554 omap_i2c_idle(dev);
555 return r;
556 }
557
558 static u32
559 omap_i2c_func(struct i2c_adapter *adap)
560 {
561 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
562 }
563
564 static inline void
565 omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
566 {
567 dev->cmd_err |= err;
568 complete(&dev->cmd_complete);
569 }
570
571 static inline void
572 omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
573 {
574 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
575 }
576
577 /* rev1 devices are apparently only on some 15xx */
578 #ifdef CONFIG_ARCH_OMAP15XX
579
580 static irqreturn_t
581 omap_i2c_rev1_isr(int this_irq, void *dev_id)
582 {
583 struct omap_i2c_dev *dev = dev_id;
584 u16 iv, w;
585
586 if (dev->idle)
587 return IRQ_NONE;
588
589 iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
590 switch (iv) {
591 case 0x00: /* None */
592 break;
593 case 0x01: /* Arbitration lost */
594 dev_err(dev->dev, "Arbitration lost\n");
595 omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
596 break;
597 case 0x02: /* No acknowledgement */
598 omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
599 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
600 break;
601 case 0x03: /* Register access ready */
602 omap_i2c_complete_cmd(dev, 0);
603 break;
604 case 0x04: /* Receive data ready */
605 if (dev->buf_len) {
606 w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
607 *dev->buf++ = w;
608 dev->buf_len--;
609 if (dev->buf_len) {
610 *dev->buf++ = w >> 8;
611 dev->buf_len--;
612 }
613 } else
614 dev_err(dev->dev, "RRDY IRQ while no data requested\n");
615 break;
616 case 0x05: /* Transmit data ready */
617 if (dev->buf_len) {
618 w = *dev->buf++;
619 dev->buf_len--;
620 if (dev->buf_len) {
621 w |= *dev->buf++ << 8;
622 dev->buf_len--;
623 }
624 omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
625 } else
626 dev_err(dev->dev, "XRDY IRQ while no data to send\n");
627 break;
628 default:
629 return IRQ_NONE;
630 }
631
632 return IRQ_HANDLED;
633 }
634 #else
635 #define omap_i2c_rev1_isr NULL
636 #endif
637
638 static irqreturn_t
639 omap_i2c_isr(int this_irq, void *dev_id)
640 {
641 struct omap_i2c_dev *dev = dev_id;
642 u16 bits;
643 u16 stat, w;
644 int err, count = 0;
645
646 if (dev->idle)
647 return IRQ_NONE;
648
649 bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
650 while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
651 dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
652 if (count++ == 100) {
653 dev_warn(dev->dev, "Too much work in one IRQ\n");
654 break;
655 }
656
657 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
658
659 err = 0;
660 if (stat & OMAP_I2C_STAT_NACK) {
661 err |= OMAP_I2C_STAT_NACK;
662 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
663 OMAP_I2C_CON_STP);
664 }
665 if (stat & OMAP_I2C_STAT_AL) {
666 dev_err(dev->dev, "Arbitration lost\n");
667 err |= OMAP_I2C_STAT_AL;
668 }
669 if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
670 OMAP_I2C_STAT_AL))
671 omap_i2c_complete_cmd(dev, err);
672 if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
673 u8 num_bytes = 1;
674 if (dev->fifo_size) {
675 if (stat & OMAP_I2C_STAT_RRDY)
676 num_bytes = dev->fifo_size;
677 else
678 num_bytes = omap_i2c_read_reg(dev,
679 OMAP_I2C_BUFSTAT_REG);
680 }
681 while (num_bytes) {
682 num_bytes--;
683 w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
684 if (dev->buf_len) {
685 *dev->buf++ = w;
686 dev->buf_len--;
687 /* Data reg from 2430 is 8 bit wide */
688 if (!cpu_is_omap2430() &&
689 !cpu_is_omap34xx()) {
690 if (dev->buf_len) {
691 *dev->buf++ = w >> 8;
692 dev->buf_len--;
693 }
694 }
695 } else {
696 if (stat & OMAP_I2C_STAT_RRDY)
697 dev_err(dev->dev,
698 "RRDY IRQ while no data"
699 " requested\n");
700 if (stat & OMAP_I2C_STAT_RDR)
701 dev_err(dev->dev,
702 "RDR IRQ while no data"
703 " requested\n");
704 break;
705 }
706 }
707 omap_i2c_ack_stat(dev,
708 stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
709 continue;
710 }
711 if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
712 u8 num_bytes = 1;
713 if (dev->fifo_size) {
714 if (stat & OMAP_I2C_STAT_XRDY)
715 num_bytes = dev->fifo_size;
716 else
717 num_bytes = omap_i2c_read_reg(dev,
718 OMAP_I2C_BUFSTAT_REG);
719 }
720 while (num_bytes) {
721 num_bytes--;
722 w = 0;
723 if (dev->buf_len) {
724 w = *dev->buf++;
725 dev->buf_len--;
726 /* Data reg from 2430 is 8 bit wide */
727 if (!cpu_is_omap2430() &&
728 !cpu_is_omap34xx()) {
729 if (dev->buf_len) {
730 w |= *dev->buf++ << 8;
731 dev->buf_len--;
732 }
733 }
734 } else {
735 if (stat & OMAP_I2C_STAT_XRDY)
736 dev_err(dev->dev,
737 "XRDY IRQ while no "
738 "data to send\n");
739 if (stat & OMAP_I2C_STAT_XDR)
740 dev_err(dev->dev,
741 "XDR IRQ while no "
742 "data to send\n");
743 break;
744 }
745 omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
746 }
747 omap_i2c_ack_stat(dev,
748 stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
749 continue;
750 }
751 if (stat & OMAP_I2C_STAT_ROVR) {
752 dev_err(dev->dev, "Receive overrun\n");
753 dev->cmd_err |= OMAP_I2C_STAT_ROVR;
754 }
755 if (stat & OMAP_I2C_STAT_XUDF) {
756 dev_err(dev->dev, "Transmit underflow\n");
757 dev->cmd_err |= OMAP_I2C_STAT_XUDF;
758 }
759 }
760
761 return count ? IRQ_HANDLED : IRQ_NONE;
762 }
763
764 static const struct i2c_algorithm omap_i2c_algo = {
765 .master_xfer = omap_i2c_xfer,
766 .functionality = omap_i2c_func,
767 };
768
769 static int __init
770 omap_i2c_probe(struct platform_device *pdev)
771 {
772 struct omap_i2c_dev *dev;
773 struct i2c_adapter *adap;
774 struct resource *mem, *irq, *ioarea;
775 irq_handler_t isr;
776 int r;
777 u32 speed = 0;
778
779 /* NOTE: driver uses the static register mapping */
780 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
781 if (!mem) {
782 dev_err(&pdev->dev, "no mem resource?\n");
783 return -ENODEV;
784 }
785 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
786 if (!irq) {
787 dev_err(&pdev->dev, "no irq resource?\n");
788 return -ENODEV;
789 }
790
791 ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
792 pdev->name);
793 if (!ioarea) {
794 dev_err(&pdev->dev, "I2C region already claimed\n");
795 return -EBUSY;
796 }
797
798 dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
799 if (!dev) {
800 r = -ENOMEM;
801 goto err_release_region;
802 }
803
804 if (pdev->dev.platform_data != NULL)
805 speed = *(u32 *)pdev->dev.platform_data;
806 else
807 speed = 100; /* Defualt speed */
808
809 dev->speed = speed;
810 dev->idle = 1;
811 dev->dev = &pdev->dev;
812 dev->irq = irq->start;
813 dev->base = ioremap(mem->start, mem->end - mem->start + 1);
814 if (!dev->base) {
815 r = -ENOMEM;
816 goto err_free_mem;
817 }
818
819 platform_set_drvdata(pdev, dev);
820
821 if ((r = omap_i2c_get_clocks(dev)) != 0)
822 goto err_iounmap;
823
824 omap_i2c_unidle(dev);
825
826 dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
827
828 if (cpu_is_omap2430() || cpu_is_omap34xx()) {
829 u16 s;
830
831 /* Set up the fifo size - Get total size */
832 s = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
833 dev->fifo_size = 0x8 << s;
834
835 /*
836 * Set up notification threshold as half the total available
837 * size. This is to ensure that we can handle the status on int
838 * call back latencies.
839 */
840 dev->fifo_size = (dev->fifo_size / 2);
841 dev->b_hw = 1; /* Enable hardware fixes */
842 }
843
844 /* reset ASAP, clearing any IRQs */
845 omap_i2c_init(dev);
846
847 isr = (dev->rev < OMAP_I2C_REV_2) ? omap_i2c_rev1_isr : omap_i2c_isr;
848 r = request_irq(dev->irq, isr, 0, pdev->name, dev);
849
850 if (r) {
851 dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
852 goto err_unuse_clocks;
853 }
854
855 dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n",
856 pdev->id, dev->rev >> 4, dev->rev & 0xf, dev->speed);
857
858 omap_i2c_idle(dev);
859
860 adap = &dev->adapter;
861 i2c_set_adapdata(adap, dev);
862 adap->owner = THIS_MODULE;
863 adap->class = I2C_CLASS_HWMON;
864 strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
865 adap->algo = &omap_i2c_algo;
866 adap->dev.parent = &pdev->dev;
867
868 /* i2c device drivers may be active on return from add_adapter() */
869 adap->nr = pdev->id;
870 r = i2c_add_numbered_adapter(adap);
871 if (r) {
872 dev_err(dev->dev, "failure adding adapter\n");
873 goto err_free_irq;
874 }
875
876 return 0;
877
878 err_free_irq:
879 free_irq(dev->irq, dev);
880 err_unuse_clocks:
881 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
882 omap_i2c_idle(dev);
883 omap_i2c_put_clocks(dev);
884 err_iounmap:
885 iounmap(dev->base);
886 err_free_mem:
887 platform_set_drvdata(pdev, NULL);
888 kfree(dev);
889 err_release_region:
890 release_mem_region(mem->start, (mem->end - mem->start) + 1);
891
892 return r;
893 }
894
895 static int
896 omap_i2c_remove(struct platform_device *pdev)
897 {
898 struct omap_i2c_dev *dev = platform_get_drvdata(pdev);
899 struct resource *mem;
900
901 platform_set_drvdata(pdev, NULL);
902
903 free_irq(dev->irq, dev);
904 i2c_del_adapter(&dev->adapter);
905 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
906 omap_i2c_put_clocks(dev);
907 iounmap(dev->base);
908 kfree(dev);
909 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
910 release_mem_region(mem->start, (mem->end - mem->start) + 1);
911 return 0;
912 }
913
914 static struct platform_driver omap_i2c_driver = {
915 .probe = omap_i2c_probe,
916 .remove = omap_i2c_remove,
917 .driver = {
918 .name = "i2c_omap",
919 .owner = THIS_MODULE,
920 },
921 };
922
923 /* I2C may be needed to bring up other drivers */
924 static int __init
925 omap_i2c_init_driver(void)
926 {
927 return platform_driver_register(&omap_i2c_driver);
928 }
929 subsys_initcall(omap_i2c_init_driver);
930
931 static void __exit omap_i2c_exit_driver(void)
932 {
933 platform_driver_unregister(&omap_i2c_driver);
934 }
935 module_exit(omap_i2c_exit_driver);
936
937 MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
938 MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
939 MODULE_LICENSE("GPL");
940 MODULE_ALIAS("platform:i2c_omap");
Support for the Chinese Samsung S3C2440 based development boards