1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * i2c_adap_pxa.c
4 *
5 * I2C adapter for the PXA I2C bus access.
6 *
7 * Copyright (C) 2002 Intrinsyc Software Inc.
8 * Copyright (C) 2004-2005 Deep Blue Solutions Ltd.
9 *
10 * History:
11 * Apr 2002: Initial version [CS]
12 * Jun 2002: Properly separated algo/adap [FB]
13 * Jan 2003: Fixed several bugs concerning interrupt handling [Kai-Uwe Bloem]
14 * Jan 2003: added limited signal handling [Kai-Uwe Bloem]
15 * Sep 2004: Major rework to ensure efficient bus handling [RMK]
16 * Dec 2004: Added support for PXA27x and slave device probing [Liam Girdwood]
17 * Feb 2005: Rework slave mode handling [RMK]
18 */
19 #include <linux/clk.h>
20 #include <linux/delay.h>
21 #include <linux/err.h>
22 #include <linux/errno.h>
23 #include <linux/gpio/consumer.h>
24 #include <linux/i2c.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/io.h>
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/of.h>
31 #include <linux/of_device.h>
32 #include <linux/pinctrl/consumer.h>
33 #include <linux/platform_device.h>
34 #include <linux/platform_data/i2c-pxa.h>
35 #include <linux/property.h>
36 #include <linux/slab.h>
37
38 /* I2C register field definitions */
39 #define IBMR_SDAS (1 << 0)
40 #define IBMR_SCLS (1 << 1)
41
42 #define ICR_START (1 << 0) /* start bit */
43 #define ICR_STOP (1 << 1) /* stop bit */
44 #define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
45 #define ICR_TB (1 << 3) /* transfer byte bit */
46 #define ICR_MA (1 << 4) /* master abort */
47 #define ICR_SCLE (1 << 5) /* master clock enable */
48 #define ICR_IUE (1 << 6) /* unit enable */
49 #define ICR_GCD (1 << 7) /* general call disable */
50 #define ICR_ITEIE (1 << 8) /* enable tx interrupts */
51 #define ICR_IRFIE (1 << 9) /* enable rx interrupts */
52 #define ICR_BEIE (1 << 10) /* enable bus error ints */
53 #define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
54 #define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
55 #define ICR_SADIE (1 << 13) /* slave address detected int enable */
56 #define ICR_UR (1 << 14) /* unit reset */
57 #define ICR_FM (1 << 15) /* fast mode */
58 #define ICR_HS (1 << 16) /* High Speed mode */
59 #define ICR_A3700_FM (1 << 16) /* fast mode for armada-3700 */
60 #define ICR_A3700_HS (1 << 17) /* high speed mode for armada-3700 */
61 #define ICR_GPIOEN (1 << 19) /* enable GPIO mode for SCL in HS */
62
63 #define ISR_RWM (1 << 0) /* read/write mode */
64 #define ISR_ACKNAK (1 << 1) /* ack/nak status */
65 #define ISR_UB (1 << 2) /* unit busy */
66 #define ISR_IBB (1 << 3) /* bus busy */
67 #define ISR_SSD (1 << 4) /* slave stop detected */
68 #define ISR_ALD (1 << 5) /* arbitration loss detected */
69 #define ISR_ITE (1 << 6) /* tx buffer empty */
70 #define ISR_IRF (1 << 7) /* rx buffer full */
71 #define ISR_GCAD (1 << 8) /* general call address detected */
72 #define ISR_SAD (1 << 9) /* slave address detected */
73 #define ISR_BED (1 << 10) /* bus error no ACK/NAK */
74
75 #define ILCR_SLV_SHIFT 0
76 #define ILCR_SLV_MASK (0x1FF << ILCR_SLV_SHIFT)
77 #define ILCR_FLV_SHIFT 9
78 #define ILCR_FLV_MASK (0x1FF << ILCR_FLV_SHIFT)
79 #define ILCR_HLVL_SHIFT 18
80 #define ILCR_HLVL_MASK (0x1FF << ILCR_HLVL_SHIFT)
81 #define ILCR_HLVH_SHIFT 27
82 #define ILCR_HLVH_MASK (0x1F << ILCR_HLVH_SHIFT)
83
84 #define IWCR_CNT_SHIFT 0
85 #define IWCR_CNT_MASK (0x1F << IWCR_CNT_SHIFT)
86 #define IWCR_HS_CNT1_SHIFT 5
87 #define IWCR_HS_CNT1_MASK (0x1F << IWCR_HS_CNT1_SHIFT)
88 #define IWCR_HS_CNT2_SHIFT 10
89 #define IWCR_HS_CNT2_MASK (0x1F << IWCR_HS_CNT2_SHIFT)
90
91 /* need a longer timeout if we're dealing with the fact we may well be
92 * looking at a multi-master environment
93 */
94 #define DEF_TIMEOUT 32
95
96 #define NO_SLAVE (-ENXIO)
97 #define BUS_ERROR (-EREMOTEIO)
98 #define XFER_NAKED (-ECONNREFUSED)
99 #define I2C_RETRY (-2000) /* an error has occurred retry transmit */
100
101 /* ICR initialize bit values
102 *
103 * 15 FM 0 (100 kHz operation)
104 * 14 UR 0 (No unit reset)
105 * 13 SADIE 0 (Disables the unit from interrupting on slave addresses
106 * matching its slave address)
107 * 12 ALDIE 0 (Disables the unit from interrupt when it loses arbitration
108 * in master mode)
109 * 11 SSDIE 0 (Disables interrupts from a slave stop detected, in slave mode)
110 * 10 BEIE 1 (Enable interrupts from detected bus errors, no ACK sent)
111 * 9 IRFIE 1 (Enable interrupts from full buffer received)
112 * 8 ITEIE 1 (Enables the I2C unit to interrupt when transmit buffer empty)
113 * 7 GCD 1 (Disables i2c unit response to general call messages as a slave)
114 * 6 IUE 0 (Disable unit until we change settings)
115 * 5 SCLE 1 (Enables the i2c clock output for master mode (drives SCL)
116 * 4 MA 0 (Only send stop with the ICR stop bit)
117 * 3 TB 0 (We are not transmitting a byte initially)
118 * 2 ACKNAK 0 (Send an ACK after the unit receives a byte)
119 * 1 STOP 0 (Do not send a STOP)
120 * 0 START 0 (Do not send a START)
121 */
122 #define I2C_ICR_INIT (ICR_BEIE | ICR_IRFIE | ICR_ITEIE | ICR_GCD | ICR_SCLE)
123
124 /* I2C status register init values
125 *
126 * 10 BED 1 (Clear bus error detected)
127 * 9 SAD 1 (Clear slave address detected)
128 * 7 IRF 1 (Clear IDBR Receive Full)
129 * 6 ITE 1 (Clear IDBR Transmit Empty)
130 * 5 ALD 1 (Clear Arbitration Loss Detected)
131 * 4 SSD 1 (Clear Slave Stop Detected)
132 */
133 #define I2C_ISR_INIT 0x7FF /* status register init */
134
135 struct pxa_reg_layout {
136 u32 ibmr;
137 u32 idbr;
138 u32 icr;
139 u32 isr;
140 u32 isar;
141 u32 ilcr;
142 u32 iwcr;
143 u32 fm;
144 u32 hs;
145 };
146
147 enum pxa_i2c_types {
148 REGS_PXA2XX,
149 REGS_PXA3XX,
150 REGS_CE4100,
151 REGS_PXA910,
152 REGS_A3700,
153 };
154
155 /* I2C register layout definitions */
156 static struct pxa_reg_layout pxa_reg_layout[] = {
157 [REGS_PXA2XX] = {
158 .ibmr = 0x00,
159 .idbr = 0x08,
160 .icr = 0x10,
161 .isr = 0x18,
162 .isar = 0x20,
163 .fm = ICR_FM,
164 .hs = ICR_HS,
165 },
166 [REGS_PXA3XX] = {
167 .ibmr = 0x00,
168 .idbr = 0x04,
169 .icr = 0x08,
170 .isr = 0x0c,
171 .isar = 0x10,
172 .fm = ICR_FM,
173 .hs = ICR_HS,
174 },
175 [REGS_CE4100] = {
176 .ibmr = 0x14,
177 .idbr = 0x0c,
178 .icr = 0x00,
179 .isr = 0x04,
180 /* no isar register */
181 .fm = ICR_FM,
182 .hs = ICR_HS,
183 },
184 [REGS_PXA910] = {
185 .ibmr = 0x00,
186 .idbr = 0x08,
187 .icr = 0x10,
188 .isr = 0x18,
189 .isar = 0x20,
190 .ilcr = 0x28,
191 .iwcr = 0x30,
192 .fm = ICR_FM,
193 .hs = ICR_HS,
194 },
195 [REGS_A3700] = {
196 .ibmr = 0x00,
197 .idbr = 0x04,
198 .icr = 0x08,
199 .isr = 0x0c,
200 .isar = 0x10,
201 .fm = ICR_A3700_FM,
202 .hs = ICR_A3700_HS,
203 },
204 };
205
206 static const struct of_device_id i2c_pxa_dt_ids[] = {
207 { .compatible = "mrvl,pxa-i2c", .data = (void *)REGS_PXA2XX },
208 { .compatible = "mrvl,pwri2c", .data = (void *)REGS_PXA3XX },
209 { .compatible = "mrvl,mmp-twsi", .data = (void *)REGS_PXA910 },
210 { .compatible = "marvell,armada-3700-i2c", .data = (void *)REGS_A3700 },
211 {}
212 };
213 MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids);
214
215 static const struct platform_device_id i2c_pxa_id_table[] = {
216 { "pxa2xx-i2c", REGS_PXA2XX },
217 { "pxa3xx-pwri2c", REGS_PXA3XX },
218 { "ce4100-i2c", REGS_CE4100 },
219 { "pxa910-i2c", REGS_PXA910 },
220 { "armada-3700-i2c", REGS_A3700 },
221 { }
222 };
223 MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
224
225 struct pxa_i2c {
226 spinlock_t lock;
227 wait_queue_head_t wait;
228 struct i2c_msg *msg;
229 unsigned int msg_num;
230 unsigned int msg_idx;
231 unsigned int msg_ptr;
232 unsigned int slave_addr;
233 unsigned int req_slave_addr;
234
235 struct i2c_adapter adap;
236 struct clk *clk;
237 #ifdef CONFIG_I2C_PXA_SLAVE
238 struct i2c_client *slave;
239 #endif
240
241 unsigned int irqlogidx;
242 u32 isrlog[32];
243 u32 icrlog[32];
244
245 void __iomem *reg_base;
246 void __iomem *reg_ibmr;
247 void __iomem *reg_idbr;
248 void __iomem *reg_icr;
249 void __iomem *reg_isr;
250 void __iomem *reg_isar;
251 void __iomem *reg_ilcr;
252 void __iomem *reg_iwcr;
253
254 unsigned long iobase;
255 unsigned long iosize;
256
257 int irq;
258 unsigned int use_pio :1;
259 unsigned int fast_mode :1;
260 unsigned int high_mode:1;
261 unsigned char master_code;
262 unsigned long rate;
263 bool highmode_enter;
264 u32 fm_mask;
265 u32 hs_mask;
266
267 struct i2c_bus_recovery_info recovery;
268 struct pinctrl *pinctrl;
269 struct pinctrl_state *pinctrl_default;
270 struct pinctrl_state *pinctrl_recovery;
271 };
272
273 #define _IBMR(i2c) ((i2c)->reg_ibmr)
274 #define _IDBR(i2c) ((i2c)->reg_idbr)
275 #define _ICR(i2c) ((i2c)->reg_icr)
276 #define _ISR(i2c) ((i2c)->reg_isr)
277 #define _ISAR(i2c) ((i2c)->reg_isar)
278 #define _ILCR(i2c) ((i2c)->reg_ilcr)
279 #define _IWCR(i2c) ((i2c)->reg_iwcr)
280
281 /*
282 * I2C Slave mode address
283 */
284 #define I2C_PXA_SLAVE_ADDR 0x1
285
286 #ifdef DEBUG
287
288 struct bits {
289 u32 mask;
290 const char *set;
291 const char *unset;
292 };
293 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
294
295 static inline void
decode_bits(const char * prefix,const struct bits * bits,int num,u32 val)296 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
297 {
298 printk("%s %08x:", prefix, val);
299 while (num--) {
300 const char *str = val & bits->mask ? bits->set : bits->unset;
301 if (str)
302 pr_cont(" %s", str);
303 bits++;
304 }
305 pr_cont("\n");
306 }
307
308 static const struct bits isr_bits[] = {
309 PXA_BIT(ISR_RWM, "RX", "TX"),
310 PXA_BIT(ISR_ACKNAK, "NAK", "ACK"),
311 PXA_BIT(ISR_UB, "Bsy", "Rdy"),
312 PXA_BIT(ISR_IBB, "BusBsy", "BusRdy"),
313 PXA_BIT(ISR_SSD, "SlaveStop", NULL),
314 PXA_BIT(ISR_ALD, "ALD", NULL),
315 PXA_BIT(ISR_ITE, "TxEmpty", NULL),
316 PXA_BIT(ISR_IRF, "RxFull", NULL),
317 PXA_BIT(ISR_GCAD, "GenCall", NULL),
318 PXA_BIT(ISR_SAD, "SlaveAddr", NULL),
319 PXA_BIT(ISR_BED, "BusErr", NULL),
320 };
321
decode_ISR(unsigned int val)322 static void decode_ISR(unsigned int val)
323 {
324 decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
325 }
326
327 #ifdef CONFIG_I2C_PXA_SLAVE
328 static const struct bits icr_bits[] = {
329 PXA_BIT(ICR_START, "START", NULL),
330 PXA_BIT(ICR_STOP, "STOP", NULL),
331 PXA_BIT(ICR_ACKNAK, "ACKNAK", NULL),
332 PXA_BIT(ICR_TB, "TB", NULL),
333 PXA_BIT(ICR_MA, "MA", NULL),
334 PXA_BIT(ICR_SCLE, "SCLE", "scle"),
335 PXA_BIT(ICR_IUE, "IUE", "iue"),
336 PXA_BIT(ICR_GCD, "GCD", NULL),
337 PXA_BIT(ICR_ITEIE, "ITEIE", NULL),
338 PXA_BIT(ICR_IRFIE, "IRFIE", NULL),
339 PXA_BIT(ICR_BEIE, "BEIE", NULL),
340 PXA_BIT(ICR_SSDIE, "SSDIE", NULL),
341 PXA_BIT(ICR_ALDIE, "ALDIE", NULL),
342 PXA_BIT(ICR_SADIE, "SADIE", NULL),
343 PXA_BIT(ICR_UR, "UR", "ur"),
344 };
345
decode_ICR(unsigned int val)346 static void decode_ICR(unsigned int val)
347 {
348 decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
349 }
350 #endif
351
352 static unsigned int i2c_debug = DEBUG;
353
i2c_pxa_show_state(struct pxa_i2c * i2c,int lno,const char * fname)354 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
355 {
356 dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
357 readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
358 }
359
360 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
361
i2c_pxa_scream_blue_murder(struct pxa_i2c * i2c,const char * why)362 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
363 {
364 unsigned int i;
365 struct device *dev = &i2c->adap.dev;
366
367 dev_err(dev, "slave_0x%x error: %s\n",
368 i2c->req_slave_addr >> 1, why);
369 dev_err(dev, "msg_num: %d msg_idx: %d msg_ptr: %d\n",
370 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
371 dev_err(dev, "IBMR: %08x IDBR: %08x ICR: %08x ISR: %08x\n",
372 readl(_IBMR(i2c)), readl(_IDBR(i2c)), readl(_ICR(i2c)),
373 readl(_ISR(i2c)));
374 dev_err(dev, "log:");
375 for (i = 0; i < i2c->irqlogidx; i++)
376 pr_cont(" [%03x:%05x]", i2c->isrlog[i], i2c->icrlog[i]);
377 pr_cont("\n");
378 }
379
380 #else /* ifdef DEBUG */
381
382 #define i2c_debug 0
383
384 #define show_state(i2c) do { } while (0)
385 #define decode_ISR(val) do { } while (0)
386 #define decode_ICR(val) do { } while (0)
387 #define i2c_pxa_scream_blue_murder(i2c, why) do { } while (0)
388
389 #endif /* ifdef DEBUG / else */
390
391 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
392
i2c_pxa_is_slavemode(struct pxa_i2c * i2c)393 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
394 {
395 return !(readl(_ICR(i2c)) & ICR_SCLE);
396 }
397
i2c_pxa_abort(struct pxa_i2c * i2c)398 static void i2c_pxa_abort(struct pxa_i2c *i2c)
399 {
400 int i = 250;
401
402 if (i2c_pxa_is_slavemode(i2c)) {
403 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
404 return;
405 }
406
407 while ((i > 0) && (readl(_IBMR(i2c)) & IBMR_SDAS) == 0) {
408 unsigned long icr = readl(_ICR(i2c));
409
410 icr &= ~ICR_START;
411 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
412
413 writel(icr, _ICR(i2c));
414
415 show_state(i2c);
416
417 mdelay(1);
418 i --;
419 }
420
421 writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
422 _ICR(i2c));
423 }
424
i2c_pxa_wait_bus_not_busy(struct pxa_i2c * i2c)425 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
426 {
427 int timeout = DEF_TIMEOUT;
428 u32 isr;
429
430 while (1) {
431 isr = readl(_ISR(i2c));
432 if (!(isr & (ISR_IBB | ISR_UB)))
433 return 0;
434
435 if (isr & ISR_SAD)
436 timeout += 4;
437
438 if (!timeout--)
439 break;
440
441 msleep(2);
442 show_state(i2c);
443 }
444
445 show_state(i2c);
446
447 return I2C_RETRY;
448 }
449
i2c_pxa_wait_master(struct pxa_i2c * i2c)450 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
451 {
452 unsigned long timeout = jiffies + HZ*4;
453
454 while (time_before(jiffies, timeout)) {
455 if (i2c_debug > 1)
456 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
457 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
458
459 if (readl(_ISR(i2c)) & ISR_SAD) {
460 if (i2c_debug > 0)
461 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
462 goto out;
463 }
464
465 /* wait for unit and bus being not busy, and we also do a
466 * quick check of the i2c lines themselves to ensure they've
467 * gone high...
468 */
469 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 &&
470 readl(_IBMR(i2c)) == (IBMR_SCLS | IBMR_SDAS)) {
471 if (i2c_debug > 0)
472 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
473 return 1;
474 }
475
476 msleep(1);
477 }
478
479 if (i2c_debug > 0)
480 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
481 out:
482 return 0;
483 }
484
i2c_pxa_set_master(struct pxa_i2c * i2c)485 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
486 {
487 if (i2c_debug)
488 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
489
490 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
491 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
492 if (!i2c_pxa_wait_master(i2c)) {
493 dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
494 return I2C_RETRY;
495 }
496 }
497
498 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
499 return 0;
500 }
501
502 #ifdef CONFIG_I2C_PXA_SLAVE
i2c_pxa_wait_slave(struct pxa_i2c * i2c)503 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
504 {
505 unsigned long timeout = jiffies + HZ*1;
506
507 /* wait for stop */
508
509 show_state(i2c);
510
511 while (time_before(jiffies, timeout)) {
512 if (i2c_debug > 1)
513 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
514 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
515
516 if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
517 (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
518 (readl(_ICR(i2c)) & ICR_SCLE) == 0) {
519 if (i2c_debug > 1)
520 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
521 return 1;
522 }
523
524 msleep(1);
525 }
526
527 if (i2c_debug > 0)
528 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
529 return 0;
530 }
531
532 /*
533 * clear the hold on the bus, and take of anything else
534 * that has been configured
535 */
i2c_pxa_set_slave(struct pxa_i2c * i2c,int errcode)536 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
537 {
538 show_state(i2c);
539
540 if (errcode < 0) {
541 udelay(100); /* simple delay */
542 } else {
543 /* we need to wait for the stop condition to end */
544
545 /* if we where in stop, then clear... */
546 if (readl(_ICR(i2c)) & ICR_STOP) {
547 udelay(100);
548 writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
549 }
550
551 if (!i2c_pxa_wait_slave(i2c)) {
552 dev_err(&i2c->adap.dev, "%s: wait timedout\n",
553 __func__);
554 return;
555 }
556 }
557
558 writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
559 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
560
561 if (i2c_debug) {
562 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
563 decode_ICR(readl(_ICR(i2c)));
564 }
565 }
566 #else
567 #define i2c_pxa_set_slave(i2c, err) do { } while (0)
568 #endif
569
i2c_pxa_do_reset(struct pxa_i2c * i2c)570 static void i2c_pxa_do_reset(struct pxa_i2c *i2c)
571 {
572 /* reset according to 9.8 */
573 writel(ICR_UR, _ICR(i2c));
574 writel(I2C_ISR_INIT, _ISR(i2c));
575 writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
576
577 if (i2c->reg_isar && IS_ENABLED(CONFIG_I2C_PXA_SLAVE))
578 writel(i2c->slave_addr, _ISAR(i2c));
579
580 /* set control register values */
581 writel(I2C_ICR_INIT | (i2c->fast_mode ? i2c->fm_mask : 0), _ICR(i2c));
582 writel(readl(_ICR(i2c)) | (i2c->high_mode ? i2c->hs_mask : 0), _ICR(i2c));
583
584 #ifdef CONFIG_I2C_PXA_SLAVE
585 dev_info(&i2c->adap.dev, "Enabling slave mode\n");
586 writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
587 #endif
588
589 i2c_pxa_set_slave(i2c, 0);
590 }
591
i2c_pxa_enable(struct pxa_i2c * i2c)592 static void i2c_pxa_enable(struct pxa_i2c *i2c)
593 {
594 /* enable unit */
595 writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
596 udelay(100);
597 }
598
i2c_pxa_reset(struct pxa_i2c * i2c)599 static void i2c_pxa_reset(struct pxa_i2c *i2c)
600 {
601 pr_debug("Resetting I2C Controller Unit\n");
602
603 /* abort any transfer currently under way */
604 i2c_pxa_abort(i2c);
605 i2c_pxa_do_reset(i2c);
606 i2c_pxa_enable(i2c);
607 }
608
609
610 #ifdef CONFIG_I2C_PXA_SLAVE
611 /*
612 * PXA I2C Slave mode
613 */
614
i2c_pxa_slave_txempty(struct pxa_i2c * i2c,u32 isr)615 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
616 {
617 if (isr & ISR_BED) {
618 /* what should we do here? */
619 } else {
620 u8 byte = 0;
621
622 if (i2c->slave != NULL)
623 i2c_slave_event(i2c->slave, I2C_SLAVE_READ_PROCESSED,
624 &byte);
625
626 writel(byte, _IDBR(i2c));
627 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */
628 }
629 }
630
i2c_pxa_slave_rxfull(struct pxa_i2c * i2c,u32 isr)631 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
632 {
633 u8 byte = readl(_IDBR(i2c));
634
635 if (i2c->slave != NULL)
636 i2c_slave_event(i2c->slave, I2C_SLAVE_WRITE_RECEIVED, &byte);
637
638 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
639 }
640
i2c_pxa_slave_start(struct pxa_i2c * i2c,u32 isr)641 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
642 {
643 int timeout;
644
645 if (i2c_debug > 0)
646 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
647 (isr & ISR_RWM) ? 'r' : 't');
648
649 if (i2c->slave != NULL) {
650 if (isr & ISR_RWM) {
651 u8 byte = 0;
652
653 i2c_slave_event(i2c->slave, I2C_SLAVE_READ_REQUESTED,
654 &byte);
655 writel(byte, _IDBR(i2c));
656 } else {
657 i2c_slave_event(i2c->slave, I2C_SLAVE_WRITE_REQUESTED,
658 NULL);
659 }
660 }
661
662 /*
663 * slave could interrupt in the middle of us generating a
664 * start condition... if this happens, we'd better back off
665 * and stop holding the poor thing up
666 */
667 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
668 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
669
670 timeout = 0x10000;
671
672 while (1) {
673 if ((readl(_IBMR(i2c)) & IBMR_SCLS) == IBMR_SCLS)
674 break;
675
676 timeout--;
677
678 if (timeout <= 0) {
679 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
680 break;
681 }
682 }
683
684 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
685 }
686
i2c_pxa_slave_stop(struct pxa_i2c * i2c)687 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
688 {
689 if (i2c_debug > 2)
690 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
691
692 if (i2c->slave != NULL)
693 i2c_slave_event(i2c->slave, I2C_SLAVE_STOP, NULL);
694
695 if (i2c_debug > 2)
696 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
697
698 /*
699 * If we have a master-mode message waiting,
700 * kick it off now that the slave has completed.
701 */
702 if (i2c->msg)
703 i2c_pxa_master_complete(i2c, I2C_RETRY);
704 }
705
i2c_pxa_slave_reg(struct i2c_client * slave)706 static int i2c_pxa_slave_reg(struct i2c_client *slave)
707 {
708 struct pxa_i2c *i2c = slave->adapter->algo_data;
709
710 if (i2c->slave)
711 return -EBUSY;
712
713 if (!i2c->reg_isar)
714 return -EAFNOSUPPORT;
715
716 i2c->slave = slave;
717 i2c->slave_addr = slave->addr;
718
719 writel(i2c->slave_addr, _ISAR(i2c));
720
721 return 0;
722 }
723
i2c_pxa_slave_unreg(struct i2c_client * slave)724 static int i2c_pxa_slave_unreg(struct i2c_client *slave)
725 {
726 struct pxa_i2c *i2c = slave->adapter->algo_data;
727
728 WARN_ON(!i2c->slave);
729
730 i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
731 writel(i2c->slave_addr, _ISAR(i2c));
732
733 i2c->slave = NULL;
734
735 return 0;
736 }
737 #else
i2c_pxa_slave_txempty(struct pxa_i2c * i2c,u32 isr)738 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
739 {
740 if (isr & ISR_BED) {
741 /* what should we do here? */
742 } else {
743 writel(0, _IDBR(i2c));
744 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
745 }
746 }
747
i2c_pxa_slave_rxfull(struct pxa_i2c * i2c,u32 isr)748 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
749 {
750 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
751 }
752
i2c_pxa_slave_start(struct pxa_i2c * i2c,u32 isr)753 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
754 {
755 int timeout;
756
757 /*
758 * slave could interrupt in the middle of us generating a
759 * start condition... if this happens, we'd better back off
760 * and stop holding the poor thing up
761 */
762 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
763 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
764
765 timeout = 0x10000;
766
767 while (1) {
768 if ((readl(_IBMR(i2c)) & IBMR_SCLS) == IBMR_SCLS)
769 break;
770
771 timeout--;
772
773 if (timeout <= 0) {
774 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
775 break;
776 }
777 }
778
779 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
780 }
781
i2c_pxa_slave_stop(struct pxa_i2c * i2c)782 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
783 {
784 if (i2c->msg)
785 i2c_pxa_master_complete(i2c, I2C_RETRY);
786 }
787 #endif
788
789 /*
790 * PXA I2C Master mode
791 */
792
i2c_pxa_start_message(struct pxa_i2c * i2c)793 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
794 {
795 u32 icr;
796
797 /*
798 * Step 1: target slave address into IDBR
799 */
800 i2c->req_slave_addr = i2c_8bit_addr_from_msg(i2c->msg);
801 writel(i2c->req_slave_addr, _IDBR(i2c));
802
803 /*
804 * Step 2: initiate the write.
805 */
806 icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
807 writel(icr | ICR_START | ICR_TB, _ICR(i2c));
808 }
809
i2c_pxa_stop_message(struct pxa_i2c * i2c)810 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
811 {
812 u32 icr;
813
814 /* Clear the START, STOP, ACK, TB and MA flags */
815 icr = readl(_ICR(i2c));
816 icr &= ~(ICR_START | ICR_STOP | ICR_ACKNAK | ICR_TB | ICR_MA);
817 writel(icr, _ICR(i2c));
818 }
819
820 /*
821 * PXA I2C send master code
822 * 1. Load master code to IDBR and send it.
823 * Note for HS mode, set ICR [GPIOEN].
824 * 2. Wait until win arbitration.
825 */
i2c_pxa_send_mastercode(struct pxa_i2c * i2c)826 static int i2c_pxa_send_mastercode(struct pxa_i2c *i2c)
827 {
828 u32 icr;
829 long time_left;
830
831 spin_lock_irq(&i2c->lock);
832 i2c->highmode_enter = true;
833 writel(i2c->master_code, _IDBR(i2c));
834
835 icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
836 icr |= ICR_GPIOEN | ICR_START | ICR_TB | ICR_ITEIE;
837 writel(icr, _ICR(i2c));
838
839 spin_unlock_irq(&i2c->lock);
840 time_left = wait_event_timeout(i2c->wait,
841 i2c->highmode_enter == false, HZ * 1);
842
843 i2c->highmode_enter = false;
844
845 return (time_left == 0) ? I2C_RETRY : 0;
846 }
847
848 /*
849 * i2c_pxa_master_complete - complete the message and wake up.
850 */
i2c_pxa_master_complete(struct pxa_i2c * i2c,int ret)851 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
852 {
853 i2c->msg_ptr = 0;
854 i2c->msg = NULL;
855 i2c->msg_idx ++;
856 i2c->msg_num = 0;
857 if (ret)
858 i2c->msg_idx = ret;
859 if (!i2c->use_pio)
860 wake_up(&i2c->wait);
861 }
862
i2c_pxa_irq_txempty(struct pxa_i2c * i2c,u32 isr)863 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
864 {
865 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
866
867 again:
868 /*
869 * If ISR_ALD is set, we lost arbitration.
870 */
871 if (isr & ISR_ALD) {
872 /*
873 * Do we need to do anything here? The PXA docs
874 * are vague about what happens.
875 */
876 i2c_pxa_scream_blue_murder(i2c, "ALD set");
877
878 /*
879 * We ignore this error. We seem to see spurious ALDs
880 * for seemingly no reason. If we handle them as I think
881 * they should, we end up causing an I2C error, which
882 * is painful for some systems.
883 */
884 return; /* ignore */
885 }
886
887 if ((isr & ISR_BED) &&
888 (!((i2c->msg->flags & I2C_M_IGNORE_NAK) &&
889 (isr & ISR_ACKNAK)))) {
890 int ret = BUS_ERROR;
891
892 /*
893 * I2C bus error - either the device NAK'd us, or
894 * something more serious happened. If we were NAK'd
895 * on the initial address phase, we can retry.
896 */
897 if (isr & ISR_ACKNAK) {
898 if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
899 ret = NO_SLAVE;
900 else
901 ret = XFER_NAKED;
902 }
903 i2c_pxa_master_complete(i2c, ret);
904 } else if (isr & ISR_RWM) {
905 /*
906 * Read mode. We have just sent the address byte, and
907 * now we must initiate the transfer.
908 */
909 if (i2c->msg_ptr == i2c->msg->len - 1 &&
910 i2c->msg_idx == i2c->msg_num - 1)
911 icr |= ICR_STOP | ICR_ACKNAK;
912
913 icr |= ICR_ALDIE | ICR_TB;
914 } else if (i2c->msg_ptr < i2c->msg->len) {
915 /*
916 * Write mode. Write the next data byte.
917 */
918 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
919
920 icr |= ICR_ALDIE | ICR_TB;
921
922 /*
923 * If this is the last byte of the last message or last byte
924 * of any message with I2C_M_STOP (e.g. SCCB), send a STOP.
925 */
926 if ((i2c->msg_ptr == i2c->msg->len) &&
927 ((i2c->msg->flags & I2C_M_STOP) ||
928 (i2c->msg_idx == i2c->msg_num - 1)))
929 icr |= ICR_STOP;
930
931 } else if (i2c->msg_idx < i2c->msg_num - 1) {
932 /*
933 * Next segment of the message.
934 */
935 i2c->msg_ptr = 0;
936 i2c->msg_idx ++;
937 i2c->msg++;
938
939 /*
940 * If we aren't doing a repeated start and address,
941 * go back and try to send the next byte. Note that
942 * we do not support switching the R/W direction here.
943 */
944 if (i2c->msg->flags & I2C_M_NOSTART)
945 goto again;
946
947 /*
948 * Write the next address.
949 */
950 i2c->req_slave_addr = i2c_8bit_addr_from_msg(i2c->msg);
951 writel(i2c->req_slave_addr, _IDBR(i2c));
952
953 /*
954 * And trigger a repeated start, and send the byte.
955 */
956 icr &= ~ICR_ALDIE;
957 icr |= ICR_START | ICR_TB;
958 } else {
959 if (i2c->msg->len == 0)
960 icr |= ICR_MA;
961 i2c_pxa_master_complete(i2c, 0);
962 }
963
964 i2c->icrlog[i2c->irqlogidx-1] = icr;
965
966 writel(icr, _ICR(i2c));
967 show_state(i2c);
968 }
969
i2c_pxa_irq_rxfull(struct pxa_i2c * i2c,u32 isr)970 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
971 {
972 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
973
974 /*
975 * Read the byte.
976 */
977 i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
978
979 if (i2c->msg_ptr < i2c->msg->len) {
980 /*
981 * If this is the last byte of the last
982 * message, send a STOP.
983 */
984 if (i2c->msg_ptr == i2c->msg->len - 1)
985 icr |= ICR_STOP | ICR_ACKNAK;
986
987 icr |= ICR_ALDIE | ICR_TB;
988 } else {
989 i2c_pxa_master_complete(i2c, 0);
990 }
991
992 i2c->icrlog[i2c->irqlogidx-1] = icr;
993
994 writel(icr, _ICR(i2c));
995 }
996
997 #define VALID_INT_SOURCE (ISR_SSD | ISR_ALD | ISR_ITE | ISR_IRF | \
998 ISR_SAD | ISR_BED)
i2c_pxa_handler(int this_irq,void * dev_id)999 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
1000 {
1001 struct pxa_i2c *i2c = dev_id;
1002 u32 isr = readl(_ISR(i2c));
1003
1004 if (!(isr & VALID_INT_SOURCE))
1005 return IRQ_NONE;
1006
1007 if (i2c_debug > 2 && 0) {
1008 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
1009 __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
1010 decode_ISR(isr);
1011 }
1012
1013 if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
1014 i2c->isrlog[i2c->irqlogidx++] = isr;
1015
1016 show_state(i2c);
1017
1018 /*
1019 * Always clear all pending IRQs.
1020 */
1021 writel(isr & VALID_INT_SOURCE, _ISR(i2c));
1022
1023 if (isr & ISR_SAD)
1024 i2c_pxa_slave_start(i2c, isr);
1025 if (isr & ISR_SSD)
1026 i2c_pxa_slave_stop(i2c);
1027
1028 if (i2c_pxa_is_slavemode(i2c)) {
1029 if (isr & ISR_ITE)
1030 i2c_pxa_slave_txempty(i2c, isr);
1031 if (isr & ISR_IRF)
1032 i2c_pxa_slave_rxfull(i2c, isr);
1033 } else if (i2c->msg && (!i2c->highmode_enter)) {
1034 if (isr & ISR_ITE)
1035 i2c_pxa_irq_txempty(i2c, isr);
1036 if (isr & ISR_IRF)
1037 i2c_pxa_irq_rxfull(i2c, isr);
1038 } else if ((isr & ISR_ITE) && i2c->highmode_enter) {
1039 i2c->highmode_enter = false;
1040 wake_up(&i2c->wait);
1041 } else {
1042 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
1043 }
1044
1045 return IRQ_HANDLED;
1046 }
1047
1048 /*
1049 * We are protected by the adapter bus mutex.
1050 */
i2c_pxa_do_xfer(struct pxa_i2c * i2c,struct i2c_msg * msg,int num)1051 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
1052 {
1053 long time_left;
1054 int ret;
1055
1056 /*
1057 * Wait for the bus to become free.
1058 */
1059 ret = i2c_pxa_wait_bus_not_busy(i2c);
1060 if (ret) {
1061 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
1062 i2c_recover_bus(&i2c->adap);
1063 goto out;
1064 }
1065
1066 /*
1067 * Set master mode.
1068 */
1069 ret = i2c_pxa_set_master(i2c);
1070 if (ret) {
1071 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
1072 goto out;
1073 }
1074
1075 if (i2c->high_mode) {
1076 ret = i2c_pxa_send_mastercode(i2c);
1077 if (ret) {
1078 dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
1079 goto out;
1080 }
1081 }
1082
1083 spin_lock_irq(&i2c->lock);
1084
1085 i2c->msg = msg;
1086 i2c->msg_num = num;
1087 i2c->msg_idx = 0;
1088 i2c->msg_ptr = 0;
1089 i2c->irqlogidx = 0;
1090
1091 i2c_pxa_start_message(i2c);
1092
1093 spin_unlock_irq(&i2c->lock);
1094
1095 /*
1096 * The rest of the processing occurs in the interrupt handler.
1097 */
1098 time_left = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
1099 i2c_pxa_stop_message(i2c);
1100
1101 /*
1102 * We place the return code in i2c->msg_idx.
1103 */
1104 ret = i2c->msg_idx;
1105
1106 if (!time_left && i2c->msg_num) {
1107 i2c_pxa_scream_blue_murder(i2c, "timeout with active message");
1108 i2c_recover_bus(&i2c->adap);
1109 ret = I2C_RETRY;
1110 }
1111
1112 out:
1113 return ret;
1114 }
1115
i2c_pxa_internal_xfer(struct pxa_i2c * i2c,struct i2c_msg * msgs,int num,int (* xfer)(struct pxa_i2c *,struct i2c_msg *,int num))1116 static int i2c_pxa_internal_xfer(struct pxa_i2c *i2c,
1117 struct i2c_msg *msgs, int num,
1118 int (*xfer)(struct pxa_i2c *,
1119 struct i2c_msg *, int num))
1120 {
1121 int ret, i;
1122
1123 for (i = 0; ; ) {
1124 ret = xfer(i2c, msgs, num);
1125 if (ret != I2C_RETRY && ret != NO_SLAVE)
1126 goto out;
1127 if (++i >= i2c->adap.retries)
1128 break;
1129
1130 if (i2c_debug)
1131 dev_dbg(&i2c->adap.dev, "Retrying transmission\n");
1132 udelay(100);
1133 }
1134 if (ret != NO_SLAVE)
1135 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
1136 ret = -EREMOTEIO;
1137 out:
1138 i2c_pxa_set_slave(i2c, ret);
1139 return ret;
1140 }
1141
i2c_pxa_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1142 static int i2c_pxa_xfer(struct i2c_adapter *adap,
1143 struct i2c_msg msgs[], int num)
1144 {
1145 struct pxa_i2c *i2c = adap->algo_data;
1146
1147 return i2c_pxa_internal_xfer(i2c, msgs, num, i2c_pxa_do_xfer);
1148 }
1149
i2c_pxa_functionality(struct i2c_adapter * adap)1150 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
1151 {
1152 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
1153 I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_NOSTART;
1154 }
1155
1156 static const struct i2c_algorithm i2c_pxa_algorithm = {
1157 .master_xfer = i2c_pxa_xfer,
1158 .functionality = i2c_pxa_functionality,
1159 #ifdef CONFIG_I2C_PXA_SLAVE
1160 .reg_slave = i2c_pxa_slave_reg,
1161 .unreg_slave = i2c_pxa_slave_unreg,
1162 #endif
1163 };
1164
1165 /* Non-interrupt mode support */
i2c_pxa_pio_set_master(struct pxa_i2c * i2c)1166 static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
1167 {
1168 /* make timeout the same as for interrupt based functions */
1169 long timeout = 2 * DEF_TIMEOUT;
1170
1171 /*
1172 * Wait for the bus to become free.
1173 */
1174 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB))
1175 udelay(1000);
1176
1177 if (timeout < 0) {
1178 show_state(i2c);
1179 dev_err(&i2c->adap.dev,
1180 "i2c_pxa: timeout waiting for bus free (set_master)\n");
1181 return I2C_RETRY;
1182 }
1183
1184 /*
1185 * Set master mode.
1186 */
1187 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
1188
1189 return 0;
1190 }
1191
i2c_pxa_do_pio_xfer(struct pxa_i2c * i2c,struct i2c_msg * msg,int num)1192 static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
1193 struct i2c_msg *msg, int num)
1194 {
1195 unsigned long timeout = 500000; /* 5 seconds */
1196 int ret = 0;
1197
1198 ret = i2c_pxa_pio_set_master(i2c);
1199 if (ret)
1200 goto out;
1201
1202 i2c->msg = msg;
1203 i2c->msg_num = num;
1204 i2c->msg_idx = 0;
1205 i2c->msg_ptr = 0;
1206 i2c->irqlogidx = 0;
1207
1208 i2c_pxa_start_message(i2c);
1209
1210 while (i2c->msg_num > 0 && --timeout) {
1211 i2c_pxa_handler(0, i2c);
1212 udelay(10);
1213 }
1214
1215 i2c_pxa_stop_message(i2c);
1216
1217 /*
1218 * We place the return code in i2c->msg_idx.
1219 */
1220 ret = i2c->msg_idx;
1221
1222 out:
1223 if (timeout == 0) {
1224 i2c_pxa_scream_blue_murder(i2c, "timeout (do_pio_xfer)");
1225 ret = I2C_RETRY;
1226 }
1227
1228 return ret;
1229 }
1230
i2c_pxa_pio_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1231 static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
1232 struct i2c_msg msgs[], int num)
1233 {
1234 struct pxa_i2c *i2c = adap->algo_data;
1235
1236 /* If the I2C controller is disabled we need to reset it
1237 (probably due to a suspend/resume destroying state). We do
1238 this here as we can then avoid worrying about resuming the
1239 controller before its users. */
1240 if (!(readl(_ICR(i2c)) & ICR_IUE))
1241 i2c_pxa_reset(i2c);
1242
1243 return i2c_pxa_internal_xfer(i2c, msgs, num, i2c_pxa_do_pio_xfer);
1244 }
1245
1246 static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
1247 .master_xfer = i2c_pxa_pio_xfer,
1248 .functionality = i2c_pxa_functionality,
1249 #ifdef CONFIG_I2C_PXA_SLAVE
1250 .reg_slave = i2c_pxa_slave_reg,
1251 .unreg_slave = i2c_pxa_slave_unreg,
1252 #endif
1253 };
1254
i2c_pxa_probe_dt(struct platform_device * pdev,struct pxa_i2c * i2c,enum pxa_i2c_types * i2c_types)1255 static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c,
1256 enum pxa_i2c_types *i2c_types)
1257 {
1258 struct device_node *np = pdev->dev.of_node;
1259
1260 if (!pdev->dev.of_node)
1261 return 1;
1262
1263 /* For device tree we always use the dynamic or alias-assigned ID */
1264 i2c->adap.nr = -1;
1265
1266 i2c->use_pio = of_property_read_bool(np, "mrvl,i2c-polling");
1267 i2c->fast_mode = of_property_read_bool(np, "mrvl,i2c-fast-mode");
1268
1269 *i2c_types = (enum pxa_i2c_types)device_get_match_data(&pdev->dev);
1270
1271 return 0;
1272 }
1273
i2c_pxa_probe_pdata(struct platform_device * pdev,struct pxa_i2c * i2c,enum pxa_i2c_types * i2c_types)1274 static int i2c_pxa_probe_pdata(struct platform_device *pdev,
1275 struct pxa_i2c *i2c,
1276 enum pxa_i2c_types *i2c_types)
1277 {
1278 struct i2c_pxa_platform_data *plat = dev_get_platdata(&pdev->dev);
1279 const struct platform_device_id *id = platform_get_device_id(pdev);
1280
1281 *i2c_types = id->driver_data;
1282 if (plat) {
1283 i2c->use_pio = plat->use_pio;
1284 i2c->fast_mode = plat->fast_mode;
1285 i2c->high_mode = plat->high_mode;
1286 i2c->master_code = plat->master_code;
1287 if (!i2c->master_code)
1288 i2c->master_code = 0xe;
1289 i2c->rate = plat->rate;
1290 }
1291 return 0;
1292 }
1293
i2c_pxa_prepare_recovery(struct i2c_adapter * adap)1294 static void i2c_pxa_prepare_recovery(struct i2c_adapter *adap)
1295 {
1296 struct pxa_i2c *i2c = adap->algo_data;
1297 u32 ibmr = readl(_IBMR(i2c));
1298
1299 /*
1300 * Program the GPIOs to reflect the current I2C bus state while
1301 * we transition to recovery; this avoids glitching the bus.
1302 */
1303 gpiod_set_value(i2c->recovery.scl_gpiod, ibmr & IBMR_SCLS);
1304 gpiod_set_value(i2c->recovery.sda_gpiod, ibmr & IBMR_SDAS);
1305
1306 WARN_ON(pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_recovery));
1307 }
1308
i2c_pxa_unprepare_recovery(struct i2c_adapter * adap)1309 static void i2c_pxa_unprepare_recovery(struct i2c_adapter *adap)
1310 {
1311 struct pxa_i2c *i2c = adap->algo_data;
1312 u32 isr;
1313
1314 /*
1315 * The bus should now be free. Clear up the I2C controller before
1316 * handing control of the bus back to avoid the bus changing state.
1317 */
1318 isr = readl(_ISR(i2c));
1319 if (isr & (ISR_UB | ISR_IBB)) {
1320 dev_dbg(&i2c->adap.dev,
1321 "recovery: resetting controller, ISR=0x%08x\n", isr);
1322 i2c_pxa_do_reset(i2c);
1323 }
1324
1325 WARN_ON(pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_default));
1326
1327 dev_dbg(&i2c->adap.dev, "recovery: IBMR 0x%08x ISR 0x%08x\n",
1328 readl(_IBMR(i2c)), readl(_ISR(i2c)));
1329
1330 i2c_pxa_enable(i2c);
1331 }
1332
i2c_pxa_init_recovery(struct pxa_i2c * i2c)1333 static int i2c_pxa_init_recovery(struct pxa_i2c *i2c)
1334 {
1335 struct i2c_bus_recovery_info *bri = &i2c->recovery;
1336 struct device *dev = i2c->adap.dev.parent;
1337
1338 /*
1339 * When slave mode is enabled, we are not the only master on the bus.
1340 * Bus recovery can only be performed when we are the master, which
1341 * we can't be certain of. Therefore, when slave mode is enabled, do
1342 * not configure bus recovery.
1343 */
1344 if (IS_ENABLED(CONFIG_I2C_PXA_SLAVE))
1345 return 0;
1346
1347 i2c->pinctrl = devm_pinctrl_get(dev);
1348 if (PTR_ERR(i2c->pinctrl) == -ENODEV)
1349 i2c->pinctrl = NULL;
1350 if (IS_ERR(i2c->pinctrl))
1351 return PTR_ERR(i2c->pinctrl);
1352
1353 if (!i2c->pinctrl)
1354 return 0;
1355
1356 i2c->pinctrl_default = pinctrl_lookup_state(i2c->pinctrl,
1357 PINCTRL_STATE_DEFAULT);
1358 i2c->pinctrl_recovery = pinctrl_lookup_state(i2c->pinctrl, "recovery");
1359
1360 if (IS_ERR(i2c->pinctrl_default) || IS_ERR(i2c->pinctrl_recovery)) {
1361 dev_info(dev, "missing pinmux recovery information: %ld %ld\n",
1362 PTR_ERR(i2c->pinctrl_default),
1363 PTR_ERR(i2c->pinctrl_recovery));
1364 return 0;
1365 }
1366
1367 /*
1368 * Claiming GPIOs can influence the pinmux state, and may glitch the
1369 * I2C bus. Do this carefully.
1370 */
1371 bri->scl_gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
1372 if (bri->scl_gpiod == ERR_PTR(-EPROBE_DEFER))
1373 return -EPROBE_DEFER;
1374 if (IS_ERR(bri->scl_gpiod)) {
1375 dev_info(dev, "missing scl gpio recovery information: %pe\n",
1376 bri->scl_gpiod);
1377 return 0;
1378 }
1379
1380 /*
1381 * We have SCL. Pull SCL low and wait a bit so that SDA glitches
1382 * have no effect.
1383 */
1384 gpiod_direction_output(bri->scl_gpiod, 0);
1385 udelay(10);
1386 bri->sda_gpiod = devm_gpiod_get(dev, "sda", GPIOD_OUT_HIGH_OPEN_DRAIN);
1387
1388 /* Wait a bit in case of a SDA glitch, and then release SCL. */
1389 udelay(10);
1390 gpiod_direction_output(bri->scl_gpiod, 1);
1391
1392 if (bri->sda_gpiod == ERR_PTR(-EPROBE_DEFER))
1393 return -EPROBE_DEFER;
1394
1395 if (IS_ERR(bri->sda_gpiod)) {
1396 dev_info(dev, "missing sda gpio recovery information: %pe\n",
1397 bri->sda_gpiod);
1398 return 0;
1399 }
1400
1401 bri->prepare_recovery = i2c_pxa_prepare_recovery;
1402 bri->unprepare_recovery = i2c_pxa_unprepare_recovery;
1403 bri->recover_bus = i2c_generic_scl_recovery;
1404
1405 i2c->adap.bus_recovery_info = bri;
1406
1407 /*
1408 * Claiming GPIOs can change the pinmux state, which confuses the
1409 * pinctrl since pinctrl's idea of the current setting is unaffected
1410 * by the pinmux change caused by claiming the GPIO. Work around that
1411 * by switching pinctrl to the GPIO state here. We do it this way to
1412 * avoid glitching the I2C bus.
1413 */
1414 pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_recovery);
1415
1416 return pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_default);
1417 }
1418
i2c_pxa_probe(struct platform_device * dev)1419 static int i2c_pxa_probe(struct platform_device *dev)
1420 {
1421 struct i2c_pxa_platform_data *plat = dev_get_platdata(&dev->dev);
1422 enum pxa_i2c_types i2c_type;
1423 struct pxa_i2c *i2c;
1424 struct resource *res;
1425 int ret, irq;
1426
1427 i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL);
1428 if (!i2c)
1429 return -ENOMEM;
1430
1431 /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
1432 i2c->adap.nr = dev->id;
1433 i2c->adap.owner = THIS_MODULE;
1434 i2c->adap.retries = 5;
1435 i2c->adap.algo_data = i2c;
1436 i2c->adap.dev.parent = &dev->dev;
1437 #ifdef CONFIG_OF
1438 i2c->adap.dev.of_node = dev->dev.of_node;
1439 #endif
1440
1441 i2c->reg_base = devm_platform_get_and_ioremap_resource(dev, 0, &res);
1442 if (IS_ERR(i2c->reg_base))
1443 return PTR_ERR(i2c->reg_base);
1444
1445 irq = platform_get_irq(dev, 0);
1446 if (irq < 0)
1447 return irq;
1448
1449 ret = i2c_pxa_init_recovery(i2c);
1450 if (ret)
1451 return ret;
1452
1453 ret = i2c_pxa_probe_dt(dev, i2c, &i2c_type);
1454 if (ret > 0)
1455 ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
1456 if (ret < 0)
1457 return ret;
1458
1459 spin_lock_init(&i2c->lock);
1460 init_waitqueue_head(&i2c->wait);
1461
1462 strscpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
1463
1464 i2c->clk = devm_clk_get(&dev->dev, NULL);
1465 if (IS_ERR(i2c->clk))
1466 return dev_err_probe(&dev->dev, PTR_ERR(i2c->clk),
1467 "failed to get the clk\n");
1468
1469 i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
1470 i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[i2c_type].idbr;
1471 i2c->reg_icr = i2c->reg_base + pxa_reg_layout[i2c_type].icr;
1472 i2c->reg_isr = i2c->reg_base + pxa_reg_layout[i2c_type].isr;
1473 i2c->fm_mask = pxa_reg_layout[i2c_type].fm;
1474 i2c->hs_mask = pxa_reg_layout[i2c_type].hs;
1475
1476 if (i2c_type != REGS_CE4100)
1477 i2c->reg_isar = i2c->reg_base + pxa_reg_layout[i2c_type].isar;
1478
1479 if (i2c_type == REGS_PXA910) {
1480 i2c->reg_ilcr = i2c->reg_base + pxa_reg_layout[i2c_type].ilcr;
1481 i2c->reg_iwcr = i2c->reg_base + pxa_reg_layout[i2c_type].iwcr;
1482 }
1483
1484 i2c->iobase = res->start;
1485 i2c->iosize = resource_size(res);
1486
1487 i2c->irq = irq;
1488
1489 i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
1490 i2c->highmode_enter = false;
1491
1492 if (plat) {
1493 i2c->adap.class = plat->class;
1494 }
1495
1496 if (i2c->high_mode) {
1497 if (i2c->rate) {
1498 clk_set_rate(i2c->clk, i2c->rate);
1499 pr_info("i2c: <%s> set rate to %ld\n",
1500 i2c->adap.name, clk_get_rate(i2c->clk));
1501 } else
1502 pr_warn("i2c: <%s> clock rate not set\n",
1503 i2c->adap.name);
1504 }
1505
1506 clk_prepare_enable(i2c->clk);
1507
1508 if (i2c->use_pio) {
1509 i2c->adap.algo = &i2c_pxa_pio_algorithm;
1510 } else {
1511 i2c->adap.algo = &i2c_pxa_algorithm;
1512 ret = devm_request_irq(&dev->dev, irq, i2c_pxa_handler,
1513 IRQF_SHARED | IRQF_NO_SUSPEND,
1514 dev_name(&dev->dev), i2c);
1515 if (ret) {
1516 dev_err(&dev->dev, "failed to request irq: %d\n", ret);
1517 goto ereqirq;
1518 }
1519 }
1520
1521 i2c_pxa_reset(i2c);
1522
1523 ret = i2c_add_numbered_adapter(&i2c->adap);
1524 if (ret < 0)
1525 goto ereqirq;
1526
1527 platform_set_drvdata(dev, i2c);
1528
1529 #ifdef CONFIG_I2C_PXA_SLAVE
1530 dev_info(&i2c->adap.dev, " PXA I2C adapter, slave address %d\n",
1531 i2c->slave_addr);
1532 #else
1533 dev_info(&i2c->adap.dev, " PXA I2C adapter\n");
1534 #endif
1535 return 0;
1536
1537 ereqirq:
1538 clk_disable_unprepare(i2c->clk);
1539 return ret;
1540 }
1541
i2c_pxa_remove(struct platform_device * dev)1542 static void i2c_pxa_remove(struct platform_device *dev)
1543 {
1544 struct pxa_i2c *i2c = platform_get_drvdata(dev);
1545
1546 i2c_del_adapter(&i2c->adap);
1547
1548 clk_disable_unprepare(i2c->clk);
1549 }
1550
i2c_pxa_suspend_noirq(struct device * dev)1551 static int i2c_pxa_suspend_noirq(struct device *dev)
1552 {
1553 struct pxa_i2c *i2c = dev_get_drvdata(dev);
1554
1555 clk_disable(i2c->clk);
1556
1557 return 0;
1558 }
1559
i2c_pxa_resume_noirq(struct device * dev)1560 static int i2c_pxa_resume_noirq(struct device *dev)
1561 {
1562 struct pxa_i2c *i2c = dev_get_drvdata(dev);
1563
1564 clk_enable(i2c->clk);
1565 i2c_pxa_reset(i2c);
1566
1567 return 0;
1568 }
1569
1570 static const struct dev_pm_ops i2c_pxa_dev_pm_ops = {
1571 .suspend_noirq = i2c_pxa_suspend_noirq,
1572 .resume_noirq = i2c_pxa_resume_noirq,
1573 };
1574
1575 static struct platform_driver i2c_pxa_driver = {
1576 .probe = i2c_pxa_probe,
1577 .remove_new = i2c_pxa_remove,
1578 .driver = {
1579 .name = "pxa2xx-i2c",
1580 .pm = pm_sleep_ptr(&i2c_pxa_dev_pm_ops),
1581 .of_match_table = i2c_pxa_dt_ids,
1582 },
1583 .id_table = i2c_pxa_id_table,
1584 };
1585
i2c_adap_pxa_init(void)1586 static int __init i2c_adap_pxa_init(void)
1587 {
1588 return platform_driver_register(&i2c_pxa_driver);
1589 }
1590
i2c_adap_pxa_exit(void)1591 static void __exit i2c_adap_pxa_exit(void)
1592 {
1593 platform_driver_unregister(&i2c_pxa_driver);
1594 }
1595
1596 MODULE_DESCRIPTION("Intel PXA2XX I2C adapter");
1597 MODULE_LICENSE("GPL");
1598
1599 subsys_initcall(i2c_adap_pxa_init);
1600 module_exit(i2c_adap_pxa_exit);
1601