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Input: document the MT event slot protocol
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / i2c / busses / i2c-omap.c
blob7674efb553786e4e2a639c5a5b263362564b626b
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 #include <linux/slab.h>
41 #include <linux/i2c-omap.h>
42
43 /* I2C controller revisions */
44 #define OMAP_I2C_REV_2 0x20
45
46 /* I2C controller revisions present on specific hardware */
47 #define OMAP_I2C_REV_ON_2430 0x36
48 #define OMAP_I2C_REV_ON_3430 0x3C
49 #define OMAP_I2C_REV_ON_4430 0x40
50
51 /* timeout waiting for the controller to respond */
52 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
53
54 /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
55 enum {
56 OMAP_I2C_REV_REG = 0,
57 OMAP_I2C_IE_REG,
58 OMAP_I2C_STAT_REG,
59 OMAP_I2C_IV_REG,
60 OMAP_I2C_WE_REG,
61 OMAP_I2C_SYSS_REG,
62 OMAP_I2C_BUF_REG,
63 OMAP_I2C_CNT_REG,
64 OMAP_I2C_DATA_REG,
65 OMAP_I2C_SYSC_REG,
66 OMAP_I2C_CON_REG,
67 OMAP_I2C_OA_REG,
68 OMAP_I2C_SA_REG,
69 OMAP_I2C_PSC_REG,
70 OMAP_I2C_SCLL_REG,
71 OMAP_I2C_SCLH_REG,
72 OMAP_I2C_SYSTEST_REG,
73 OMAP_I2C_BUFSTAT_REG,
74 OMAP_I2C_REVNB_LO,
75 OMAP_I2C_REVNB_HI,
76 OMAP_I2C_IRQSTATUS_RAW,
77 OMAP_I2C_IRQENABLE_SET,
78 OMAP_I2C_IRQENABLE_CLR,
79 };
80
81 /* I2C Interrupt Enable Register (OMAP_I2C_IE): */
82 #define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */
83 #define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer drain int enable */
84 #define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */
85 #define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */
86 #define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */
87 #define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */
88 #define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */
89
90 /* I2C Status Register (OMAP_I2C_STAT): */
91 #define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */
92 #define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */
93 #define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */
94 #define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */
95 #define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */
96 #define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */
97 #define OMAP_I2C_STAT_AD0 (1 << 8) /* Address zero */
98 #define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */
99 #define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */
100 #define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */
101 #define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */
102 #define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */
103
104 /* I2C WE wakeup enable register */
105 #define OMAP_I2C_WE_XDR_WE (1 << 14) /* TX drain wakup */
106 #define OMAP_I2C_WE_RDR_WE (1 << 13) /* RX drain wakeup */
107 #define OMAP_I2C_WE_AAS_WE (1 << 9) /* Address as slave wakeup*/
108 #define OMAP_I2C_WE_BF_WE (1 << 8) /* Bus free wakeup */
109 #define OMAP_I2C_WE_STC_WE (1 << 6) /* Start condition wakeup */
110 #define OMAP_I2C_WE_GC_WE (1 << 5) /* General call wakeup */
111 #define OMAP_I2C_WE_DRDY_WE (1 << 3) /* TX/RX data ready wakeup */
112 #define OMAP_I2C_WE_ARDY_WE (1 << 2) /* Reg access ready wakeup */
113 #define OMAP_I2C_WE_NACK_WE (1 << 1) /* No acknowledgment wakeup */
114 #define OMAP_I2C_WE_AL_WE (1 << 0) /* Arbitration lost wakeup */
115
116 #define OMAP_I2C_WE_ALL (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
117 OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
118 OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
119 OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
120 OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
121
122 /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
123 #define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */
124 #define OMAP_I2C_BUF_RXFIF_CLR (1 << 14) /* RX FIFO Clear */
125 #define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */
126 #define OMAP_I2C_BUF_TXFIF_CLR (1 << 6) /* TX FIFO Clear */
127
128 /* I2C Configuration Register (OMAP_I2C_CON): */
129 #define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */
130 #define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */
131 #define OMAP_I2C_CON_OPMODE_HS (1 << 12) /* High Speed support */
132 #define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */
133 #define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */
134 #define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */
135 #define OMAP_I2C_CON_XA (1 << 8) /* Expand address */
136 #define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */
137 #define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */
138 #define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */
139
140 /* I2C SCL time value when Master */
141 #define OMAP_I2C_SCLL_HSSCLL 8
142 #define OMAP_I2C_SCLH_HSSCLH 8
143
144 /* I2C System Test Register (OMAP_I2C_SYSTEST): */
145 #ifdef DEBUG
146 #define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */
147 #define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */
148 #define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */
149 #define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */
150 #define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */
151 #define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */
152 #define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */
153 #define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */
154 #endif
155
156 /* OCP_SYSSTATUS bit definitions */
157 #define SYSS_RESETDONE_MASK (1 << 0)
158
159 /* OCP_SYSCONFIG bit definitions */
160 #define SYSC_CLOCKACTIVITY_MASK (0x3 << 8)
161 #define SYSC_SIDLEMODE_MASK (0x3 << 3)
162 #define SYSC_ENAWAKEUP_MASK (1 << 2)
163 #define SYSC_SOFTRESET_MASK (1 << 1)
164 #define SYSC_AUTOIDLE_MASK (1 << 0)
165
166 #define SYSC_IDLEMODE_SMART 0x2
167 #define SYSC_CLOCKACTIVITY_FCLK 0x2
168
169 /* Errata definitions */
170 #define I2C_OMAP_ERRATA_I207 (1 << 0)
171 #define I2C_OMAP3_1P153 (1 << 1)
172
173 struct omap_i2c_dev {
174 struct device *dev;
175 void __iomem *base; /* virtual */
176 int irq;
177 int reg_shift; /* bit shift for I2C register addresses */
178 struct clk *iclk; /* Interface clock */
179 struct clk *fclk; /* Functional clock */
180 struct completion cmd_complete;
181 struct resource *ioarea;
182 u32 latency; /* maximum mpu wkup latency */
183 void (*set_mpu_wkup_lat)(struct device *dev,
184 long latency);
185 u32 speed; /* Speed of bus in Khz */
186 u16 cmd_err;
187 u8 *buf;
188 u8 *regs;
189 size_t buf_len;
190 struct i2c_adapter adapter;
191 u8 fifo_size; /* use as flag and value
192 * fifo_size==0 implies no fifo
193 * if set, should be trsh+1
194 */
195 u8 rev;
196 unsigned b_hw:1; /* bad h/w fixes */
197 unsigned idle:1;
198 u16 iestate; /* Saved interrupt register */
199 u16 pscstate;
200 u16 scllstate;
201 u16 sclhstate;
202 u16 bufstate;
203 u16 syscstate;
204 u16 westate;
205 u16 errata;
206 };
207
208 const static u8 reg_map[] = {
209 [OMAP_I2C_REV_REG] = 0x00,
210 [OMAP_I2C_IE_REG] = 0x01,
211 [OMAP_I2C_STAT_REG] = 0x02,
212 [OMAP_I2C_IV_REG] = 0x03,
213 [OMAP_I2C_WE_REG] = 0x03,
214 [OMAP_I2C_SYSS_REG] = 0x04,
215 [OMAP_I2C_BUF_REG] = 0x05,
216 [OMAP_I2C_CNT_REG] = 0x06,
217 [OMAP_I2C_DATA_REG] = 0x07,
218 [OMAP_I2C_SYSC_REG] = 0x08,
219 [OMAP_I2C_CON_REG] = 0x09,
220 [OMAP_I2C_OA_REG] = 0x0a,
221 [OMAP_I2C_SA_REG] = 0x0b,
222 [OMAP_I2C_PSC_REG] = 0x0c,
223 [OMAP_I2C_SCLL_REG] = 0x0d,
224 [OMAP_I2C_SCLH_REG] = 0x0e,
225 [OMAP_I2C_SYSTEST_REG] = 0x0f,
226 [OMAP_I2C_BUFSTAT_REG] = 0x10,
227 };
228
229 const static u8 omap4_reg_map[] = {
230 [OMAP_I2C_REV_REG] = 0x04,
231 [OMAP_I2C_IE_REG] = 0x2c,
232 [OMAP_I2C_STAT_REG] = 0x28,
233 [OMAP_I2C_IV_REG] = 0x34,
234 [OMAP_I2C_WE_REG] = 0x34,
235 [OMAP_I2C_SYSS_REG] = 0x90,
236 [OMAP_I2C_BUF_REG] = 0x94,
237 [OMAP_I2C_CNT_REG] = 0x98,
238 [OMAP_I2C_DATA_REG] = 0x9c,
239 [OMAP_I2C_SYSC_REG] = 0x20,
240 [OMAP_I2C_CON_REG] = 0xa4,
241 [OMAP_I2C_OA_REG] = 0xa8,
242 [OMAP_I2C_SA_REG] = 0xac,
243 [OMAP_I2C_PSC_REG] = 0xb0,
244 [OMAP_I2C_SCLL_REG] = 0xb4,
245 [OMAP_I2C_SCLH_REG] = 0xb8,
246 [OMAP_I2C_SYSTEST_REG] = 0xbC,
247 [OMAP_I2C_BUFSTAT_REG] = 0xc0,
248 [OMAP_I2C_REVNB_LO] = 0x00,
249 [OMAP_I2C_REVNB_HI] = 0x04,
250 [OMAP_I2C_IRQSTATUS_RAW] = 0x24,
251 [OMAP_I2C_IRQENABLE_SET] = 0x2c,
252 [OMAP_I2C_IRQENABLE_CLR] = 0x30,
253 };
254
255 static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
256 int reg, u16 val)
257 {
258 __raw_writew(val, i2c_dev->base +
259 (i2c_dev->regs[reg] << i2c_dev->reg_shift));
260 }
261
262 static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
263 {
264 return __raw_readw(i2c_dev->base +
265 (i2c_dev->regs[reg] << i2c_dev->reg_shift));
266 }
267
268 static int __init omap_i2c_get_clocks(struct omap_i2c_dev *dev)
269 {
270 int ret;
271
272 dev->iclk = clk_get(dev->dev, "ick");
273 if (IS_ERR(dev->iclk)) {
274 ret = PTR_ERR(dev->iclk);
275 dev->iclk = NULL;
276 return ret;
277 }
278
279 dev->fclk = clk_get(dev->dev, "fck");
280 if (IS_ERR(dev->fclk)) {
281 ret = PTR_ERR(dev->fclk);
282 if (dev->iclk != NULL) {
283 clk_put(dev->iclk);
284 dev->iclk = NULL;
285 }
286 dev->fclk = NULL;
287 return ret;
288 }
289
290 return 0;
291 }
292
293 static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
294 {
295 clk_put(dev->fclk);
296 dev->fclk = NULL;
297 clk_put(dev->iclk);
298 dev->iclk = NULL;
299 }
300
301 static void omap_i2c_unidle(struct omap_i2c_dev *dev)
302 {
303 WARN_ON(!dev->idle);
304
305 clk_enable(dev->iclk);
306 clk_enable(dev->fclk);
307 if (cpu_is_omap34xx()) {
308 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
309 omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
310 omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
311 omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
312 omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate);
313 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, dev->syscstate);
314 omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
315 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
316 }
317 dev->idle = 0;
318
319 /*
320 * Don't write to this register if the IE state is 0 as it can
321 * cause deadlock.
322 */
323 if (dev->iestate)
324 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
325 }
326
327 static void omap_i2c_idle(struct omap_i2c_dev *dev)
328 {
329 u16 iv;
330
331 WARN_ON(dev->idle);
332
333 dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
334 if (dev->rev >= OMAP_I2C_REV_ON_4430)
335 omap_i2c_write_reg(dev, OMAP_I2C_IRQENABLE_CLR, 1);
336 else
337 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
338
339 if (dev->rev < OMAP_I2C_REV_2) {
340 iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); /* Read clears */
341 } else {
342 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate);
343
344 /* Flush posted write before the dev->idle store occurs */
345 omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
346 }
347 dev->idle = 1;
348 clk_disable(dev->fclk);
349 clk_disable(dev->iclk);
350 }
351
352 static int omap_i2c_init(struct omap_i2c_dev *dev)
353 {
354 u16 psc = 0, scll = 0, sclh = 0, buf = 0;
355 u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
356 unsigned long fclk_rate = 12000000;
357 unsigned long timeout;
358 unsigned long internal_clk = 0;
359
360 if (dev->rev >= OMAP_I2C_REV_2) {
361 /* Disable I2C controller before soft reset */
362 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
363 omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) &
364 ~(OMAP_I2C_CON_EN));
365
366 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
367 /* For some reason we need to set the EN bit before the
368 * reset done bit gets set. */
369 timeout = jiffies + OMAP_I2C_TIMEOUT;
370 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
371 while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
372 SYSS_RESETDONE_MASK)) {
373 if (time_after(jiffies, timeout)) {
374 dev_warn(dev->dev, "timeout waiting "
375 "for controller reset\n");
376 return -ETIMEDOUT;
377 }
378 msleep(1);
379 }
380
381 /* SYSC register is cleared by the reset; rewrite it */
382 if (dev->rev == OMAP_I2C_REV_ON_2430) {
383
384 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
385 SYSC_AUTOIDLE_MASK);
386
387 } else if (dev->rev >= OMAP_I2C_REV_ON_3430) {
388 dev->syscstate = SYSC_AUTOIDLE_MASK;
389 dev->syscstate |= SYSC_ENAWAKEUP_MASK;
390 dev->syscstate |= (SYSC_IDLEMODE_SMART <<
391 __ffs(SYSC_SIDLEMODE_MASK));
392 dev->syscstate |= (SYSC_CLOCKACTIVITY_FCLK <<
393 __ffs(SYSC_CLOCKACTIVITY_MASK));
394
395 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
396 dev->syscstate);
397 /*
398 * Enabling all wakup sources to stop I2C freezing on
399 * WFI instruction.
400 * REVISIT: Some wkup sources might not be needed.
401 */
402 dev->westate = OMAP_I2C_WE_ALL;
403 if (dev->rev < OMAP_I2C_REV_ON_4430)
404 omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
405 dev->westate);
406 }
407 }
408 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
409
410 if (cpu_class_is_omap1()) {
411 /*
412 * The I2C functional clock is the armxor_ck, so there's
413 * no need to get "armxor_ck" separately. Now, if OMAP2420
414 * always returns 12MHz for the functional clock, we can
415 * do this bit unconditionally.
416 */
417 fclk_rate = clk_get_rate(dev->fclk);
418
419 /* TRM for 5912 says the I2C clock must be prescaled to be
420 * between 7 - 12 MHz. The XOR input clock is typically
421 * 12, 13 or 19.2 MHz. So we should have code that produces:
422 *
423 * XOR MHz Divider Prescaler
424 * 12 1 0
425 * 13 2 1
426 * 19.2 2 1
427 */
428 if (fclk_rate > 12000000)
429 psc = fclk_rate / 12000000;
430 }
431
432 if (!(cpu_class_is_omap1() || cpu_is_omap2420())) {
433
434 /*
435 * HSI2C controller internal clk rate should be 19.2 Mhz for
436 * HS and for all modes on 2430. On 34xx we can use lower rate
437 * to get longer filter period for better noise suppression.
438 * The filter is iclk (fclk for HS) period.
439 */
440 if (dev->speed > 400 || cpu_is_omap2430())
441 internal_clk = 19200;
442 else if (dev->speed > 100)
443 internal_clk = 9600;
444 else
445 internal_clk = 4000;
446 fclk_rate = clk_get_rate(dev->fclk) / 1000;
447
448 /* Compute prescaler divisor */
449 psc = fclk_rate / internal_clk;
450 psc = psc - 1;
451
452 /* If configured for High Speed */
453 if (dev->speed > 400) {
454 unsigned long scl;
455
456 /* For first phase of HS mode */
457 scl = internal_clk / 400;
458 fsscll = scl - (scl / 3) - 7;
459 fssclh = (scl / 3) - 5;
460
461 /* For second phase of HS mode */
462 scl = fclk_rate / dev->speed;
463 hsscll = scl - (scl / 3) - 7;
464 hssclh = (scl / 3) - 5;
465 } else if (dev->speed > 100) {
466 unsigned long scl;
467
468 /* Fast mode */
469 scl = internal_clk / dev->speed;
470 fsscll = scl - (scl / 3) - 7;
471 fssclh = (scl / 3) - 5;
472 } else {
473 /* Standard mode */
474 fsscll = internal_clk / (dev->speed * 2) - 7;
475 fssclh = internal_clk / (dev->speed * 2) - 5;
476 }
477 scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
478 sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
479 } else {
480 /* Program desired operating rate */
481 fclk_rate /= (psc + 1) * 1000;
482 if (psc > 2)
483 psc = 2;
484 scll = fclk_rate / (dev->speed * 2) - 7 + psc;
485 sclh = fclk_rate / (dev->speed * 2) - 7 + psc;
486 }
487
488 /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
489 omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
490
491 /* SCL low and high time values */
492 omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
493 omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
494
495 if (dev->fifo_size) {
496 /* Note: setup required fifo size - 1. RTRSH and XTRSH */
497 buf = (dev->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR |
498 (dev->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR;
499 omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
500 }
501
502 /* Take the I2C module out of reset: */
503 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
504
505 dev->errata = 0;
506
507 if (cpu_is_omap2430() || cpu_is_omap34xx())
508 dev->errata |= I2C_OMAP_ERRATA_I207;
509
510 /* Enable interrupts */
511 dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
512 OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
513 OMAP_I2C_IE_AL) | ((dev->fifo_size) ?
514 (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
515 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
516 if (cpu_is_omap34xx()) {
517 dev->pscstate = psc;
518 dev->scllstate = scll;
519 dev->sclhstate = sclh;
520 dev->bufstate = buf;
521 }
522 return 0;
523 }
524
525 /*
526 * Waiting on Bus Busy
527 */
528 static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
529 {
530 unsigned long timeout;
531
532 timeout = jiffies + OMAP_I2C_TIMEOUT;
533 while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
534 if (time_after(jiffies, timeout)) {
535 dev_warn(dev->dev, "timeout waiting for bus ready\n");
536 return -ETIMEDOUT;
537 }
538 msleep(1);
539 }
540
541 return 0;
542 }
543
544 /*
545 * Low level master read/write transaction.
546 */
547 static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
548 struct i2c_msg *msg, int stop)
549 {
550 struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
551 int r;
552 u16 w;
553
554 dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
555 msg->addr, msg->len, msg->flags, stop);
556
557 if (msg->len == 0)
558 return -EINVAL;
559
560 omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
561
562 /* REVISIT: Could the STB bit of I2C_CON be used with probing? */
563 dev->buf = msg->buf;
564 dev->buf_len = msg->len;
565
566 omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
567
568 /* Clear the FIFO Buffers */
569 w = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
570 w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
571 omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, w);
572
573 init_completion(&dev->cmd_complete);
574 dev->cmd_err = 0;
575
576 w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
577
578 /* High speed configuration */
579 if (dev->speed > 400)
580 w |= OMAP_I2C_CON_OPMODE_HS;
581
582 if (msg->flags & I2C_M_TEN)
583 w |= OMAP_I2C_CON_XA;
584 if (!(msg->flags & I2C_M_RD))
585 w |= OMAP_I2C_CON_TRX;
586
587 if (!dev->b_hw && stop)
588 w |= OMAP_I2C_CON_STP;
589
590 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
591
592 /*
593 * Don't write stt and stp together on some hardware.
594 */
595 if (dev->b_hw && stop) {
596 unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
597 u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
598 while (con & OMAP_I2C_CON_STT) {
599 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
600
601 /* Let the user know if i2c is in a bad state */
602 if (time_after(jiffies, delay)) {
603 dev_err(dev->dev, "controller timed out "
604 "waiting for start condition to finish\n");
605 return -ETIMEDOUT;
606 }
607 cpu_relax();
608 }
609
610 w |= OMAP_I2C_CON_STP;
611 w &= ~OMAP_I2C_CON_STT;
612 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
613 }
614
615 /*
616 * REVISIT: We should abort the transfer on signals, but the bus goes
617 * into arbitration and we're currently unable to recover from it.
618 */
619 if (dev->set_mpu_wkup_lat != NULL)
620 dev->set_mpu_wkup_lat(dev->dev, dev->latency);
621 r = wait_for_completion_timeout(&dev->cmd_complete,
622 OMAP_I2C_TIMEOUT);
623 if (dev->set_mpu_wkup_lat != NULL)
624 dev->set_mpu_wkup_lat(dev->dev, -1);
625 dev->buf_len = 0;
626 if (r < 0)
627 return r;
628 if (r == 0) {
629 dev_err(dev->dev, "controller timed out\n");
630 omap_i2c_init(dev);
631 return -ETIMEDOUT;
632 }
633
634 if (likely(!dev->cmd_err))
635 return 0;
636
637 /* We have an error */
638 if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
639 OMAP_I2C_STAT_XUDF)) {
640 omap_i2c_init(dev);
641 return -EIO;
642 }
643
644 if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
645 if (msg->flags & I2C_M_IGNORE_NAK)
646 return 0;
647 if (stop) {
648 w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
649 w |= OMAP_I2C_CON_STP;
650 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
651 }
652 return -EREMOTEIO;
653 }
654 return -EIO;
655 }
656
657
658 /*
659 * Prepare controller for a transaction and call omap_i2c_xfer_msg
660 * to do the work during IRQ processing.
661 */
662 static int
663 omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
664 {
665 struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
666 int i;
667 int r;
668
669 omap_i2c_unidle(dev);
670
671 r = omap_i2c_wait_for_bb(dev);
672 if (r < 0)
673 goto out;
674
675 for (i = 0; i < num; i++) {
676 r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
677 if (r != 0)
678 break;
679 }
680
681 if (r == 0)
682 r = num;
683 out:
684 omap_i2c_idle(dev);
685 return r;
686 }
687
688 static u32
689 omap_i2c_func(struct i2c_adapter *adap)
690 {
691 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
692 }
693
694 static inline void
695 omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
696 {
697 dev->cmd_err |= err;
698 complete(&dev->cmd_complete);
699 }
700
701 static inline void
702 omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
703 {
704 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
705 }
706
707 static inline void i2c_omap_errata_i207(struct omap_i2c_dev *dev, u16 stat)
708 {
709 /*
710 * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8)
711 * Not applicable for OMAP4.
712 * Under certain rare conditions, RDR could be set again
713 * when the bus is busy, then ignore the interrupt and
714 * clear the interrupt.
715 */
716 if (stat & OMAP_I2C_STAT_RDR) {
717 /* Step 1: If RDR is set, clear it */
718 omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
719
720 /* Step 2: */
721 if (!(omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
722 & OMAP_I2C_STAT_BB)) {
723
724 /* Step 3: */
725 if (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
726 & OMAP_I2C_STAT_RDR) {
727 omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
728 dev_dbg(dev->dev, "RDR when bus is busy.\n");
729 }
730
731 }
732 }
733 }
734
735 /* rev1 devices are apparently only on some 15xx */
736 #ifdef CONFIG_ARCH_OMAP15XX
737
738 static irqreturn_t
739 omap_i2c_rev1_isr(int this_irq, void *dev_id)
740 {
741 struct omap_i2c_dev *dev = dev_id;
742 u16 iv, w;
743
744 if (dev->idle)
745 return IRQ_NONE;
746
747 iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
748 switch (iv) {
749 case 0x00: /* None */
750 break;
751 case 0x01: /* Arbitration lost */
752 dev_err(dev->dev, "Arbitration lost\n");
753 omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
754 break;
755 case 0x02: /* No acknowledgement */
756 omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
757 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
758 break;
759 case 0x03: /* Register access ready */
760 omap_i2c_complete_cmd(dev, 0);
761 break;
762 case 0x04: /* Receive data ready */
763 if (dev->buf_len) {
764 w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
765 *dev->buf++ = w;
766 dev->buf_len--;
767 if (dev->buf_len) {
768 *dev->buf++ = w >> 8;
769 dev->buf_len--;
770 }
771 } else
772 dev_err(dev->dev, "RRDY IRQ while no data requested\n");
773 break;
774 case 0x05: /* Transmit data ready */
775 if (dev->buf_len) {
776 w = *dev->buf++;
777 dev->buf_len--;
778 if (dev->buf_len) {
779 w |= *dev->buf++ << 8;
780 dev->buf_len--;
781 }
782 omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
783 } else
784 dev_err(dev->dev, "XRDY IRQ while no data to send\n");
785 break;
786 default:
787 return IRQ_NONE;
788 }
789
790 return IRQ_HANDLED;
791 }
792 #else
793 #define omap_i2c_rev1_isr NULL
794 #endif
795
796 /*
797 * OMAP3430 Errata 1.153: When an XRDY/XDR is hit, wait for XUDF before writing
798 * data to DATA_REG. Otherwise some data bytes can be lost while transferring
799 * them from the memory to the I2C interface.
800 */
801 static int errata_omap3_1p153(struct omap_i2c_dev *dev, u16 *stat, int *err)
802 {
803 unsigned long timeout = 10000;
804
805 while (--timeout && !(*stat & OMAP_I2C_STAT_XUDF)) {
806 if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
807 omap_i2c_ack_stat(dev, *stat & (OMAP_I2C_STAT_XRDY |
808 OMAP_I2C_STAT_XDR));
809 *err |= OMAP_I2C_STAT_XUDF;
810 return -ETIMEDOUT;
811 }
812
813 cpu_relax();
814 *stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
815 }
816
817 if (!timeout) {
818 dev_err(dev->dev, "timeout waiting on XUDF bit\n");
819 return 0;
820 }
821
822 return 0;
823 }
824
825 static irqreturn_t
826 omap_i2c_isr(int this_irq, void *dev_id)
827 {
828 struct omap_i2c_dev *dev = dev_id;
829 u16 bits;
830 u16 stat, w;
831 int err, count = 0;
832
833 if (dev->idle)
834 return IRQ_NONE;
835
836 bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
837 while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
838 dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
839 if (count++ == 100) {
840 dev_warn(dev->dev, "Too much work in one IRQ\n");
841 break;
842 }
843
844 err = 0;
845 complete:
846 /*
847 * Ack the stat in one go, but [R/X]DR and [R/X]RDY should be
848 * acked after the data operation is complete.
849 * Ref: TRM SWPU114Q Figure 18-31
850 */
851 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat &
852 ~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
853 OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
854
855 if (stat & OMAP_I2C_STAT_NACK) {
856 err |= OMAP_I2C_STAT_NACK;
857 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
858 OMAP_I2C_CON_STP);
859 }
860 if (stat & OMAP_I2C_STAT_AL) {
861 dev_err(dev->dev, "Arbitration lost\n");
862 err |= OMAP_I2C_STAT_AL;
863 }
864 if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
865 OMAP_I2C_STAT_AL)) {
866 omap_i2c_ack_stat(dev, stat &
867 (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
868 OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
869 omap_i2c_complete_cmd(dev, err);
870 return IRQ_HANDLED;
871 }
872 if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
873 u8 num_bytes = 1;
874
875 if (dev->errata & I2C_OMAP_ERRATA_I207)
876 i2c_omap_errata_i207(dev, stat);
877
878 if (dev->fifo_size) {
879 if (stat & OMAP_I2C_STAT_RRDY)
880 num_bytes = dev->fifo_size;
881 else /* read RXSTAT on RDR interrupt */
882 num_bytes = (omap_i2c_read_reg(dev,
883 OMAP_I2C_BUFSTAT_REG)
884 >> 8) & 0x3F;
885 }
886 while (num_bytes) {
887 num_bytes--;
888 w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
889 if (dev->buf_len) {
890 *dev->buf++ = w;
891 dev->buf_len--;
892 /*
893 * Data reg in 2430, omap3 and
894 * omap4 is 8 bit wide
895 */
896 if (cpu_class_is_omap1() ||
897 cpu_is_omap2420()) {
898 if (dev->buf_len) {
899 *dev->buf++ = w >> 8;
900 dev->buf_len--;
901 }
902 }
903 } else {
904 if (stat & OMAP_I2C_STAT_RRDY)
905 dev_err(dev->dev,
906 "RRDY IRQ while no data"
907 " requested\n");
908 if (stat & OMAP_I2C_STAT_RDR)
909 dev_err(dev->dev,
910 "RDR IRQ while no data"
911 " requested\n");
912 break;
913 }
914 }
915 omap_i2c_ack_stat(dev,
916 stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
917 continue;
918 }
919 if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
920 u8 num_bytes = 1;
921 if (dev->fifo_size) {
922 if (stat & OMAP_I2C_STAT_XRDY)
923 num_bytes = dev->fifo_size;
924 else /* read TXSTAT on XDR interrupt */
925 num_bytes = omap_i2c_read_reg(dev,
926 OMAP_I2C_BUFSTAT_REG)
927 & 0x3F;
928 }
929 while (num_bytes) {
930 num_bytes--;
931 w = 0;
932 if (dev->buf_len) {
933 w = *dev->buf++;
934 dev->buf_len--;
935 /*
936 * Data reg in 2430, omap3 and
937 * omap4 is 8 bit wide
938 */
939 if (cpu_class_is_omap1() ||
940 cpu_is_omap2420()) {
941 if (dev->buf_len) {
942 w |= *dev->buf++ << 8;
943 dev->buf_len--;
944 }
945 }
946 } else {
947 if (stat & OMAP_I2C_STAT_XRDY)
948 dev_err(dev->dev,
949 "XRDY IRQ while no "
950 "data to send\n");
951 if (stat & OMAP_I2C_STAT_XDR)
952 dev_err(dev->dev,
953 "XDR IRQ while no "
954 "data to send\n");
955 break;
956 }
957
958 if ((dev->errata & I2C_OMAP3_1P153) &&
959 errata_omap3_1p153(dev, &stat, &err))
960 goto complete;
961
962 omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
963 }
964 omap_i2c_ack_stat(dev,
965 stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
966 continue;
967 }
968 if (stat & OMAP_I2C_STAT_ROVR) {
969 dev_err(dev->dev, "Receive overrun\n");
970 dev->cmd_err |= OMAP_I2C_STAT_ROVR;
971 }
972 if (stat & OMAP_I2C_STAT_XUDF) {
973 dev_err(dev->dev, "Transmit underflow\n");
974 dev->cmd_err |= OMAP_I2C_STAT_XUDF;
975 }
976 }
977
978 return count ? IRQ_HANDLED : IRQ_NONE;
979 }
980
981 static const struct i2c_algorithm omap_i2c_algo = {
982 .master_xfer = omap_i2c_xfer,
983 .functionality = omap_i2c_func,
984 };
985
986 static int __devinit
987 omap_i2c_probe(struct platform_device *pdev)
988 {
989 struct omap_i2c_dev *dev;
990 struct i2c_adapter *adap;
991 struct resource *mem, *irq, *ioarea;
992 struct omap_i2c_bus_platform_data *pdata = pdev->dev.platform_data;
993 irq_handler_t isr;
994 int r;
995 u32 speed = 0;
996
997 /* NOTE: driver uses the static register mapping */
998 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
999 if (!mem) {
1000 dev_err(&pdev->dev, "no mem resource?\n");
1001 return -ENODEV;
1002 }
1003 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
1004 if (!irq) {
1005 dev_err(&pdev->dev, "no irq resource?\n");
1006 return -ENODEV;
1007 }
1008
1009 ioarea = request_mem_region(mem->start, resource_size(mem),
1010 pdev->name);
1011 if (!ioarea) {
1012 dev_err(&pdev->dev, "I2C region already claimed\n");
1013 return -EBUSY;
1014 }
1015
1016 dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
1017 if (!dev) {
1018 r = -ENOMEM;
1019 goto err_release_region;
1020 }
1021
1022 if (pdata != NULL) {
1023 speed = pdata->clkrate;
1024 dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
1025 } else {
1026 speed = 100; /* Default speed */
1027 dev->set_mpu_wkup_lat = NULL;
1028 }
1029
1030 dev->speed = speed;
1031 dev->idle = 1;
1032 dev->dev = &pdev->dev;
1033 dev->irq = irq->start;
1034 dev->base = ioremap(mem->start, resource_size(mem));
1035 if (!dev->base) {
1036 r = -ENOMEM;
1037 goto err_free_mem;
1038 }
1039
1040 platform_set_drvdata(pdev, dev);
1041
1042 if (cpu_is_omap7xx())
1043 dev->reg_shift = 1;
1044 else if (cpu_is_omap44xx())
1045 dev->reg_shift = 0;
1046 else
1047 dev->reg_shift = 2;
1048
1049 if ((r = omap_i2c_get_clocks(dev)) != 0)
1050 goto err_iounmap;
1051
1052 if (cpu_is_omap44xx())
1053 dev->regs = (u8 *) omap4_reg_map;
1054 else
1055 dev->regs = (u8 *) reg_map;
1056
1057 omap_i2c_unidle(dev);
1058
1059 dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
1060
1061 if (dev->rev <= OMAP_I2C_REV_ON_3430)
1062 dev->errata |= I2C_OMAP3_1P153;
1063
1064 if (!(cpu_class_is_omap1() || cpu_is_omap2420())) {
1065 u16 s;
1066
1067 /* Set up the fifo size - Get total size */
1068 s = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
1069 dev->fifo_size = 0x8 << s;
1070
1071 /*
1072 * Set up notification threshold as half the total available
1073 * size. This is to ensure that we can handle the status on int
1074 * call back latencies.
1075 */
1076 if (dev->rev >= OMAP_I2C_REV_ON_4430) {
1077 dev->fifo_size = 0;
1078 dev->b_hw = 0; /* Disable hardware fixes */
1079 } else {
1080 dev->fifo_size = (dev->fifo_size / 2);
1081 dev->b_hw = 1; /* Enable hardware fixes */
1082 }
1083 /* calculate wakeup latency constraint for MPU */
1084 if (dev->set_mpu_wkup_lat != NULL)
1085 dev->latency = (1000000 * dev->fifo_size) /
1086 (1000 * speed / 8);
1087 }
1088
1089 /* reset ASAP, clearing any IRQs */
1090 omap_i2c_init(dev);
1091
1092 isr = (dev->rev < OMAP_I2C_REV_2) ? omap_i2c_rev1_isr : omap_i2c_isr;
1093 r = request_irq(dev->irq, isr, 0, pdev->name, dev);
1094
1095 if (r) {
1096 dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
1097 goto err_unuse_clocks;
1098 }
1099
1100 dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n",
1101 pdev->id, dev->rev >> 4, dev->rev & 0xf, dev->speed);
1102
1103 omap_i2c_idle(dev);
1104
1105 adap = &dev->adapter;
1106 i2c_set_adapdata(adap, dev);
1107 adap->owner = THIS_MODULE;
1108 adap->class = I2C_CLASS_HWMON;
1109 strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
1110 adap->algo = &omap_i2c_algo;
1111 adap->dev.parent = &pdev->dev;
1112
1113 /* i2c device drivers may be active on return from add_adapter() */
1114 adap->nr = pdev->id;
1115 r = i2c_add_numbered_adapter(adap);
1116 if (r) {
1117 dev_err(dev->dev, "failure adding adapter\n");
1118 goto err_free_irq;
1119 }
1120
1121 return 0;
1122
1123 err_free_irq:
1124 free_irq(dev->irq, dev);
1125 err_unuse_clocks:
1126 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
1127 omap_i2c_idle(dev);
1128 omap_i2c_put_clocks(dev);
1129 err_iounmap:
1130 iounmap(dev->base);
1131 err_free_mem:
1132 platform_set_drvdata(pdev, NULL);
1133 kfree(dev);
1134 err_release_region:
1135 release_mem_region(mem->start, resource_size(mem));
1136
1137 return r;
1138 }
1139
1140 static int
1141 omap_i2c_remove(struct platform_device *pdev)
1142 {
1143 struct omap_i2c_dev *dev = platform_get_drvdata(pdev);
1144 struct resource *mem;
1145
1146 platform_set_drvdata(pdev, NULL);
1147
1148 free_irq(dev->irq, dev);
1149 i2c_del_adapter(&dev->adapter);
1150 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
1151 omap_i2c_put_clocks(dev);
1152 iounmap(dev->base);
1153 kfree(dev);
1154 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1155 release_mem_region(mem->start, resource_size(mem));
1156 return 0;
1157 }
1158
1159 static struct platform_driver omap_i2c_driver = {
1160 .probe = omap_i2c_probe,
1161 .remove = omap_i2c_remove,
1162 .driver = {
1163 .name = "i2c_omap",
1164 .owner = THIS_MODULE,
1165 },
1166 };
1167
1168 /* I2C may be needed to bring up other drivers */
1169 static int __init
1170 omap_i2c_init_driver(void)
1171 {
1172 return platform_driver_register(&omap_i2c_driver);
1173 }
1174 subsys_initcall(omap_i2c_init_driver);
1175
1176 static void __exit omap_i2c_exit_driver(void)
1177 {
1178 platform_driver_unregister(&omap_i2c_driver);
1179 }
1180 module_exit(omap_i2c_exit_driver);
1181
1182 MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
1183 MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
1184 MODULE_LICENSE("GPL");
1185 MODULE_ALIAS("platform:i2c_omap");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree