Loading...
1/*
2 * Freescale CPM1/CPM2 I2C interface.
3 * Copyright (c) 1999 Dan Malek (dmalek@jlc.net).
4 *
5 * moved into proper i2c interface;
6 * Brad Parker (brad@heeltoe.com)
7 *
8 * Parts from dbox2_i2c.c (cvs.tuxbox.org)
9 * (C) 2000-2001 Felix Domke (tmbinc@gmx.net), Gillem (htoa@gmx.net)
10 *
11 * (C) 2007 Montavista Software, Inc.
12 * Vitaly Bordug <vitb@kernel.crashing.org>
13 *
14 * Converted to of_platform_device. Renamed to i2c-cpm.c.
15 * (C) 2007,2008 Jochen Friedrich <jochen@scram.de>
16 *
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
21 *
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
26 */
27
28#include <linux/kernel.h>
29#include <linux/module.h>
30#include <linux/delay.h>
31#include <linux/slab.h>
32#include <linux/interrupt.h>
33#include <linux/errno.h>
34#include <linux/stddef.h>
35#include <linux/i2c.h>
36#include <linux/io.h>
37#include <linux/dma-mapping.h>
38#include <linux/of_address.h>
39#include <linux/of_device.h>
40#include <linux/of_irq.h>
41#include <linux/of_platform.h>
42#include <sysdev/fsl_soc.h>
43#include <asm/cpm.h>
44
45/* Try to define this if you have an older CPU (earlier than rev D4) */
46/* However, better use a GPIO based bitbang driver in this case :/ */
47#undef I2C_CHIP_ERRATA
48
49#define CPM_MAX_READ 513
50#define CPM_MAXBD 4
51
52#define I2C_EB (0x10) /* Big endian mode */
53#define I2C_EB_CPM2 (0x30) /* Big endian mode, memory snoop */
54
55#define DPRAM_BASE ((u8 __iomem __force *)cpm_muram_addr(0))
56
57/* I2C parameter RAM. */
58struct i2c_ram {
59 ushort rbase; /* Rx Buffer descriptor base address */
60 ushort tbase; /* Tx Buffer descriptor base address */
61 u_char rfcr; /* Rx function code */
62 u_char tfcr; /* Tx function code */
63 ushort mrblr; /* Max receive buffer length */
64 uint rstate; /* Internal */
65 uint rdp; /* Internal */
66 ushort rbptr; /* Rx Buffer descriptor pointer */
67 ushort rbc; /* Internal */
68 uint rxtmp; /* Internal */
69 uint tstate; /* Internal */
70 uint tdp; /* Internal */
71 ushort tbptr; /* Tx Buffer descriptor pointer */
72 ushort tbc; /* Internal */
73 uint txtmp; /* Internal */
74 char res1[4]; /* Reserved */
75 ushort rpbase; /* Relocation pointer */
76 char res2[2]; /* Reserved */
77};
78
79#define I2COM_START 0x80
80#define I2COM_MASTER 0x01
81#define I2CER_TXE 0x10
82#define I2CER_BUSY 0x04
83#define I2CER_TXB 0x02
84#define I2CER_RXB 0x01
85#define I2MOD_EN 0x01
86
87/* I2C Registers */
88struct i2c_reg {
89 u8 i2mod;
90 u8 res1[3];
91 u8 i2add;
92 u8 res2[3];
93 u8 i2brg;
94 u8 res3[3];
95 u8 i2com;
96 u8 res4[3];
97 u8 i2cer;
98 u8 res5[3];
99 u8 i2cmr;
100};
101
102struct cpm_i2c {
103 char *base;
104 struct platform_device *ofdev;
105 struct i2c_adapter adap;
106 uint dp_addr;
107 int version; /* CPM1=1, CPM2=2 */
108 int irq;
109 int cp_command;
110 int freq;
111 struct i2c_reg __iomem *i2c_reg;
112 struct i2c_ram __iomem *i2c_ram;
113 u16 i2c_addr;
114 wait_queue_head_t i2c_wait;
115 cbd_t __iomem *tbase;
116 cbd_t __iomem *rbase;
117 u_char *txbuf[CPM_MAXBD];
118 u_char *rxbuf[CPM_MAXBD];
119 dma_addr_t txdma[CPM_MAXBD];
120 dma_addr_t rxdma[CPM_MAXBD];
121};
122
123static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
124{
125 struct cpm_i2c *cpm;
126 struct i2c_reg __iomem *i2c_reg;
127 struct i2c_adapter *adap = dev_id;
128 int i;
129
130 cpm = i2c_get_adapdata(dev_id);
131 i2c_reg = cpm->i2c_reg;
132
133 /* Clear interrupt. */
134 i = in_8(&i2c_reg->i2cer);
135 out_8(&i2c_reg->i2cer, i);
136
137 dev_dbg(&adap->dev, "Interrupt: %x\n", i);
138
139 wake_up(&cpm->i2c_wait);
140
141 return i ? IRQ_HANDLED : IRQ_NONE;
142}
143
144static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
145{
146 struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
147
148 /* Set up the I2C parameters in the parameter ram. */
149 out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
150 out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);
151
152 if (cpm->version == 1) {
153 out_8(&i2c_ram->tfcr, I2C_EB);
154 out_8(&i2c_ram->rfcr, I2C_EB);
155 } else {
156 out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
157 out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
158 }
159
160 out_be16(&i2c_ram->mrblr, CPM_MAX_READ);
161
162 out_be32(&i2c_ram->rstate, 0);
163 out_be32(&i2c_ram->rdp, 0);
164 out_be16(&i2c_ram->rbptr, 0);
165 out_be16(&i2c_ram->rbc, 0);
166 out_be32(&i2c_ram->rxtmp, 0);
167 out_be32(&i2c_ram->tstate, 0);
168 out_be32(&i2c_ram->tdp, 0);
169 out_be16(&i2c_ram->tbptr, 0);
170 out_be16(&i2c_ram->tbc, 0);
171 out_be32(&i2c_ram->txtmp, 0);
172}
173
174static void cpm_i2c_force_close(struct i2c_adapter *adap)
175{
176 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
177 struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
178
179 dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");
180
181 cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);
182
183 out_8(&i2c_reg->i2cmr, 0x00); /* Disable all interrupts */
184 out_8(&i2c_reg->i2cer, 0xff);
185}
186
187static void cpm_i2c_parse_message(struct i2c_adapter *adap,
188 struct i2c_msg *pmsg, int num, int tx, int rx)
189{
190 cbd_t __iomem *tbdf;
191 cbd_t __iomem *rbdf;
192 u_char addr;
193 u_char *tb;
194 u_char *rb;
195 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
196
197 tbdf = cpm->tbase + tx;
198 rbdf = cpm->rbase + rx;
199
200 addr = pmsg->addr << 1;
201 if (pmsg->flags & I2C_M_RD)
202 addr |= 1;
203
204 tb = cpm->txbuf[tx];
205 rb = cpm->rxbuf[rx];
206
207 /* Align read buffer */
208 rb = (u_char *) (((ulong) rb + 1) & ~1);
209
210 tb[0] = addr; /* Device address byte w/rw flag */
211
212 out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
213 out_be16(&tbdf->cbd_sc, 0);
214
215 if (!(pmsg->flags & I2C_M_NOSTART))
216 setbits16(&tbdf->cbd_sc, BD_I2C_START);
217
218 if (tx + 1 == num)
219 setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);
220
221 if (pmsg->flags & I2C_M_RD) {
222 /*
223 * To read, we need an empty buffer of the proper length.
224 * All that is used is the first byte for address, the remainder
225 * is just used for timing (and doesn't really have to exist).
226 */
227
228 dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);
229
230 out_be16(&rbdf->cbd_datlen, 0);
231 out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
232
233 if (rx + 1 == CPM_MAXBD)
234 setbits16(&rbdf->cbd_sc, BD_SC_WRAP);
235
236 eieio();
237 setbits16(&tbdf->cbd_sc, BD_SC_READY);
238 } else {
239 dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr);
240
241 memcpy(tb+1, pmsg->buf, pmsg->len);
242
243 eieio();
244 setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
245 }
246}
247
248static int cpm_i2c_check_message(struct i2c_adapter *adap,
249 struct i2c_msg *pmsg, int tx, int rx)
250{
251 cbd_t __iomem *tbdf;
252 cbd_t __iomem *rbdf;
253 u_char *tb;
254 u_char *rb;
255 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
256
257 tbdf = cpm->tbase + tx;
258 rbdf = cpm->rbase + rx;
259
260 tb = cpm->txbuf[tx];
261 rb = cpm->rxbuf[rx];
262
263 /* Align read buffer */
264 rb = (u_char *) (((uint) rb + 1) & ~1);
265
266 eieio();
267 if (pmsg->flags & I2C_M_RD) {
268 dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
269 in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));
270
271 if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
272 dev_dbg(&adap->dev, "I2C read; No ack\n");
273 return -ENXIO;
274 }
275 if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
276 dev_err(&adap->dev,
277 "I2C read; complete but rbuf empty\n");
278 return -EREMOTEIO;
279 }
280 if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
281 dev_err(&adap->dev, "I2C read; Overrun\n");
282 return -EREMOTEIO;
283 }
284 memcpy(pmsg->buf, rb, pmsg->len);
285 } else {
286 dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
287 in_be16(&tbdf->cbd_sc));
288
289 if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
290 dev_dbg(&adap->dev, "I2C write; No ack\n");
291 return -ENXIO;
292 }
293 if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
294 dev_err(&adap->dev, "I2C write; Underrun\n");
295 return -EIO;
296 }
297 if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
298 dev_err(&adap->dev, "I2C write; Collision\n");
299 return -EIO;
300 }
301 }
302 return 0;
303}
304
305static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
306{
307 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
308 struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
309 struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
310 struct i2c_msg *pmsg;
311 int ret;
312 int tptr;
313 int rptr;
314 cbd_t __iomem *tbdf;
315 cbd_t __iomem *rbdf;
316
317 /* Reset to use first buffer */
318 out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
319 out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
320
321 tbdf = cpm->tbase;
322 rbdf = cpm->rbase;
323
324 tptr = 0;
325 rptr = 0;
326
327 /*
328 * If there was a collision in the last i2c transaction,
329 * Set I2COM_MASTER as it was cleared during collision.
330 */
331 if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
332 out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);
333 }
334
335 while (tptr < num) {
336 pmsg = &msgs[tptr];
337 dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
338
339 cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
340 if (pmsg->flags & I2C_M_RD)
341 rptr++;
342 tptr++;
343 }
344 /* Start transfer now */
345 /* Enable RX/TX/Error interupts */
346 out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB);
347 out_8(&i2c_reg->i2cer, 0xff); /* Clear interrupt status */
348 /* Chip bug, set enable here */
349 setbits8(&i2c_reg->i2mod, I2MOD_EN); /* Enable */
350 /* Begin transmission */
351 setbits8(&i2c_reg->i2com, I2COM_START);
352
353 tptr = 0;
354 rptr = 0;
355
356 while (tptr < num) {
357 /* Check for outstanding messages */
358 dev_dbg(&adap->dev, "test ready.\n");
359 pmsg = &msgs[tptr];
360 if (pmsg->flags & I2C_M_RD)
361 ret = wait_event_timeout(cpm->i2c_wait,
362 (in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||
363 !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
364 1 * HZ);
365 else
366 ret = wait_event_timeout(cpm->i2c_wait,
367 !(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
368 1 * HZ);
369 if (ret == 0) {
370 ret = -EREMOTEIO;
371 dev_err(&adap->dev, "I2C transfer: timeout\n");
372 goto out_err;
373 }
374 if (ret > 0) {
375 dev_dbg(&adap->dev, "ready.\n");
376 ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
377 tptr++;
378 if (pmsg->flags & I2C_M_RD)
379 rptr++;
380 if (ret)
381 goto out_err;
382 }
383 }
384#ifdef I2C_CHIP_ERRATA
385 /*
386 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
387 * Disabling I2C too early may cause too short stop condition
388 */
389 udelay(4);
390 clrbits8(&i2c_reg->i2mod, I2MOD_EN);
391#endif
392 return (num);
393
394out_err:
395 cpm_i2c_force_close(adap);
396#ifdef I2C_CHIP_ERRATA
397 /*
398 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
399 */
400 clrbits8(&i2c_reg->i2mod, I2MOD_EN);
401#endif
402 return ret;
403}
404
405static u32 cpm_i2c_func(struct i2c_adapter *adap)
406{
407 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
408}
409
410/* -----exported algorithm data: ------------------------------------- */
411
412static const struct i2c_algorithm cpm_i2c_algo = {
413 .master_xfer = cpm_i2c_xfer,
414 .functionality = cpm_i2c_func,
415};
416
417/* CPM_MAX_READ is also limiting writes according to the code! */
418static struct i2c_adapter_quirks cpm_i2c_quirks = {
419 .max_num_msgs = CPM_MAXBD,
420 .max_read_len = CPM_MAX_READ,
421 .max_write_len = CPM_MAX_READ,
422};
423
424static const struct i2c_adapter cpm_ops = {
425 .owner = THIS_MODULE,
426 .name = "i2c-cpm",
427 .algo = &cpm_i2c_algo,
428 .quirks = &cpm_i2c_quirks,
429};
430
431static int cpm_i2c_setup(struct cpm_i2c *cpm)
432{
433 struct platform_device *ofdev = cpm->ofdev;
434 const u32 *data;
435 int len, ret, i;
436 void __iomem *i2c_base;
437 cbd_t __iomem *tbdf;
438 cbd_t __iomem *rbdf;
439 unsigned char brg;
440
441 dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");
442
443 init_waitqueue_head(&cpm->i2c_wait);
444
445 cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
446 if (!cpm->irq)
447 return -EINVAL;
448
449 /* Install interrupt handler. */
450 ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
451 &cpm->adap);
452 if (ret)
453 return ret;
454
455 /* I2C parameter RAM */
456 i2c_base = of_iomap(ofdev->dev.of_node, 1);
457 if (i2c_base == NULL) {
458 ret = -EINVAL;
459 goto out_irq;
460 }
461
462 if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) {
463
464 /* Check for and use a microcode relocation patch. */
465 cpm->i2c_ram = i2c_base;
466 cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);
467
468 /*
469 * Maybe should use cpm_muram_alloc instead of hardcoding
470 * this in micropatch.c
471 */
472 if (cpm->i2c_addr) {
473 cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
474 iounmap(i2c_base);
475 }
476
477 cpm->version = 1;
478
479 } else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) {
480 cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
481 cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
482 out_be16(i2c_base, cpm->i2c_addr);
483 iounmap(i2c_base);
484
485 cpm->version = 2;
486
487 } else {
488 iounmap(i2c_base);
489 ret = -EINVAL;
490 goto out_irq;
491 }
492
493 /* I2C control/status registers */
494 cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0);
495 if (cpm->i2c_reg == NULL) {
496 ret = -EINVAL;
497 goto out_ram;
498 }
499
500 data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
501 if (!data || len != 4) {
502 ret = -EINVAL;
503 goto out_reg;
504 }
505 cpm->cp_command = *data;
506
507 data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len);
508 if (data && len == 4)
509 cpm->adap.class = *data;
510
511 data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len);
512 if (data && len == 4)
513 cpm->freq = *data;
514 else
515 cpm->freq = 60000; /* use 60kHz i2c clock by default */
516
517 /*
518 * Allocate space for CPM_MAXBD transmit and receive buffer
519 * descriptors in the DP ram.
520 */
521 cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
522 if (!cpm->dp_addr) {
523 ret = -ENOMEM;
524 goto out_reg;
525 }
526
527 cpm->tbase = cpm_muram_addr(cpm->dp_addr);
528 cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);
529
530 /* Allocate TX and RX buffers */
531
532 tbdf = cpm->tbase;
533 rbdf = cpm->rbase;
534
535 for (i = 0; i < CPM_MAXBD; i++) {
536 cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
537 CPM_MAX_READ + 1,
538 &cpm->rxdma[i], GFP_KERNEL);
539 if (!cpm->rxbuf[i]) {
540 ret = -ENOMEM;
541 goto out_muram;
542 }
543 out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));
544
545 cpm->txbuf[i] = (unsigned char *)dma_alloc_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, &cpm->txdma[i], GFP_KERNEL);
546 if (!cpm->txbuf[i]) {
547 ret = -ENOMEM;
548 goto out_muram;
549 }
550 out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
551 }
552
553 /* Initialize Tx/Rx parameters. */
554
555 cpm_reset_i2c_params(cpm);
556
557 dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
558 cpm->i2c_ram, cpm->i2c_addr, cpm->freq);
559 dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
560 (u8 __iomem *)cpm->tbase - DPRAM_BASE,
561 (u8 __iomem *)cpm->rbase - DPRAM_BASE);
562
563 cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);
564
565 /*
566 * Select an invalid address. Just make sure we don't use loopback mode
567 */
568 out_8(&cpm->i2c_reg->i2add, 0x7f << 1);
569
570 /*
571 * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
572 * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
573 * the actual i2c bus frequency.
574 */
575 brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
576 out_8(&cpm->i2c_reg->i2brg, brg);
577
578 out_8(&cpm->i2c_reg->i2mod, 0x00);
579 out_8(&cpm->i2c_reg->i2com, I2COM_MASTER); /* Master mode */
580
581 /* Disable interrupts. */
582 out_8(&cpm->i2c_reg->i2cmr, 0);
583 out_8(&cpm->i2c_reg->i2cer, 0xff);
584
585 return 0;
586
587out_muram:
588 for (i = 0; i < CPM_MAXBD; i++) {
589 if (cpm->rxbuf[i])
590 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
591 cpm->rxbuf[i], cpm->rxdma[i]);
592 if (cpm->txbuf[i])
593 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
594 cpm->txbuf[i], cpm->txdma[i]);
595 }
596 cpm_muram_free(cpm->dp_addr);
597out_reg:
598 iounmap(cpm->i2c_reg);
599out_ram:
600 if ((cpm->version == 1) && (!cpm->i2c_addr))
601 iounmap(cpm->i2c_ram);
602 if (cpm->version == 2)
603 cpm_muram_free(cpm->i2c_addr);
604out_irq:
605 free_irq(cpm->irq, &cpm->adap);
606 return ret;
607}
608
609static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
610{
611 int i;
612
613 /* Shut down I2C. */
614 clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);
615
616 /* Disable interrupts */
617 out_8(&cpm->i2c_reg->i2cmr, 0);
618 out_8(&cpm->i2c_reg->i2cer, 0xff);
619
620 free_irq(cpm->irq, &cpm->adap);
621
622 /* Free all memory */
623 for (i = 0; i < CPM_MAXBD; i++) {
624 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
625 cpm->rxbuf[i], cpm->rxdma[i]);
626 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
627 cpm->txbuf[i], cpm->txdma[i]);
628 }
629
630 cpm_muram_free(cpm->dp_addr);
631 iounmap(cpm->i2c_reg);
632
633 if ((cpm->version == 1) && (!cpm->i2c_addr))
634 iounmap(cpm->i2c_ram);
635 if (cpm->version == 2)
636 cpm_muram_free(cpm->i2c_addr);
637}
638
639static int cpm_i2c_probe(struct platform_device *ofdev)
640{
641 int result, len;
642 struct cpm_i2c *cpm;
643 const u32 *data;
644
645 cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
646 if (!cpm)
647 return -ENOMEM;
648
649 cpm->ofdev = ofdev;
650
651 platform_set_drvdata(ofdev, cpm);
652
653 cpm->adap = cpm_ops;
654 i2c_set_adapdata(&cpm->adap, cpm);
655 cpm->adap.dev.parent = &ofdev->dev;
656 cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node);
657
658 result = cpm_i2c_setup(cpm);
659 if (result) {
660 dev_err(&ofdev->dev, "Unable to init hardware\n");
661 goto out_free;
662 }
663
664 /* register new adapter to i2c module... */
665
666 data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
667 cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1;
668 result = i2c_add_numbered_adapter(&cpm->adap);
669
670 if (result < 0) {
671 dev_err(&ofdev->dev, "Unable to register with I2C\n");
672 goto out_shut;
673 }
674
675 dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
676 cpm->adap.name);
677
678 return 0;
679out_shut:
680 cpm_i2c_shutdown(cpm);
681out_free:
682 kfree(cpm);
683
684 return result;
685}
686
687static int cpm_i2c_remove(struct platform_device *ofdev)
688{
689 struct cpm_i2c *cpm = platform_get_drvdata(ofdev);
690
691 i2c_del_adapter(&cpm->adap);
692
693 cpm_i2c_shutdown(cpm);
694
695 kfree(cpm);
696
697 return 0;
698}
699
700static const struct of_device_id cpm_i2c_match[] = {
701 {
702 .compatible = "fsl,cpm1-i2c",
703 },
704 {
705 .compatible = "fsl,cpm2-i2c",
706 },
707 {},
708};
709
710MODULE_DEVICE_TABLE(of, cpm_i2c_match);
711
712static struct platform_driver cpm_i2c_driver = {
713 .probe = cpm_i2c_probe,
714 .remove = cpm_i2c_remove,
715 .driver = {
716 .name = "fsl-i2c-cpm",
717 .of_match_table = cpm_i2c_match,
718 },
719};
720
721module_platform_driver(cpm_i2c_driver);
722
723MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
724MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
725MODULE_LICENSE("GPL");
1/*
2 * Freescale CPM1/CPM2 I2C interface.
3 * Copyright (c) 1999 Dan Malek (dmalek@jlc.net).
4 *
5 * moved into proper i2c interface;
6 * Brad Parker (brad@heeltoe.com)
7 *
8 * Parts from dbox2_i2c.c (cvs.tuxbox.org)
9 * (C) 2000-2001 Felix Domke (tmbinc@gmx.net), Gillem (htoa@gmx.net)
10 *
11 * (C) 2007 Montavista Software, Inc.
12 * Vitaly Bordug <vitb@kernel.crashing.org>
13 *
14 * Converted to of_platform_device. Renamed to i2c-cpm.c.
15 * (C) 2007,2008 Jochen Friedrich <jochen@scram.de>
16 *
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
21 *
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
26 */
27
28#include <linux/kernel.h>
29#include <linux/module.h>
30#include <linux/delay.h>
31#include <linux/slab.h>
32#include <linux/interrupt.h>
33#include <linux/errno.h>
34#include <linux/stddef.h>
35#include <linux/i2c.h>
36#include <linux/io.h>
37#include <linux/dma-mapping.h>
38#include <linux/of_address.h>
39#include <linux/of_device.h>
40#include <linux/of_irq.h>
41#include <linux/of_platform.h>
42#include <sysdev/fsl_soc.h>
43#include <asm/cpm.h>
44
45/* Try to define this if you have an older CPU (earlier than rev D4) */
46/* However, better use a GPIO based bitbang driver in this case :/ */
47#undef I2C_CHIP_ERRATA
48
49#define CPM_MAX_READ 513
50#define CPM_MAXBD 4
51
52#define I2C_EB (0x10) /* Big endian mode */
53#define I2C_EB_CPM2 (0x30) /* Big endian mode, memory snoop */
54
55#define DPRAM_BASE ((u8 __iomem __force *)cpm_muram_addr(0))
56
57/* I2C parameter RAM. */
58struct i2c_ram {
59 ushort rbase; /* Rx Buffer descriptor base address */
60 ushort tbase; /* Tx Buffer descriptor base address */
61 u_char rfcr; /* Rx function code */
62 u_char tfcr; /* Tx function code */
63 ushort mrblr; /* Max receive buffer length */
64 uint rstate; /* Internal */
65 uint rdp; /* Internal */
66 ushort rbptr; /* Rx Buffer descriptor pointer */
67 ushort rbc; /* Internal */
68 uint rxtmp; /* Internal */
69 uint tstate; /* Internal */
70 uint tdp; /* Internal */
71 ushort tbptr; /* Tx Buffer descriptor pointer */
72 ushort tbc; /* Internal */
73 uint txtmp; /* Internal */
74 char res1[4]; /* Reserved */
75 ushort rpbase; /* Relocation pointer */
76 char res2[2]; /* Reserved */
77};
78
79#define I2COM_START 0x80
80#define I2COM_MASTER 0x01
81#define I2CER_TXE 0x10
82#define I2CER_BUSY 0x04
83#define I2CER_TXB 0x02
84#define I2CER_RXB 0x01
85#define I2MOD_EN 0x01
86
87/* I2C Registers */
88struct i2c_reg {
89 u8 i2mod;
90 u8 res1[3];
91 u8 i2add;
92 u8 res2[3];
93 u8 i2brg;
94 u8 res3[3];
95 u8 i2com;
96 u8 res4[3];
97 u8 i2cer;
98 u8 res5[3];
99 u8 i2cmr;
100};
101
102struct cpm_i2c {
103 char *base;
104 struct platform_device *ofdev;
105 struct i2c_adapter adap;
106 uint dp_addr;
107 int version; /* CPM1=1, CPM2=2 */
108 int irq;
109 int cp_command;
110 int freq;
111 struct i2c_reg __iomem *i2c_reg;
112 struct i2c_ram __iomem *i2c_ram;
113 u16 i2c_addr;
114 wait_queue_head_t i2c_wait;
115 cbd_t __iomem *tbase;
116 cbd_t __iomem *rbase;
117 u_char *txbuf[CPM_MAXBD];
118 u_char *rxbuf[CPM_MAXBD];
119 dma_addr_t txdma[CPM_MAXBD];
120 dma_addr_t rxdma[CPM_MAXBD];
121};
122
123static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
124{
125 struct cpm_i2c *cpm;
126 struct i2c_reg __iomem *i2c_reg;
127 struct i2c_adapter *adap = dev_id;
128 int i;
129
130 cpm = i2c_get_adapdata(dev_id);
131 i2c_reg = cpm->i2c_reg;
132
133 /* Clear interrupt. */
134 i = in_8(&i2c_reg->i2cer);
135 out_8(&i2c_reg->i2cer, i);
136
137 dev_dbg(&adap->dev, "Interrupt: %x\n", i);
138
139 wake_up(&cpm->i2c_wait);
140
141 return i ? IRQ_HANDLED : IRQ_NONE;
142}
143
144static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
145{
146 struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
147
148 /* Set up the I2C parameters in the parameter ram. */
149 out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
150 out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);
151
152 if (cpm->version == 1) {
153 out_8(&i2c_ram->tfcr, I2C_EB);
154 out_8(&i2c_ram->rfcr, I2C_EB);
155 } else {
156 out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
157 out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
158 }
159
160 out_be16(&i2c_ram->mrblr, CPM_MAX_READ);
161
162 out_be32(&i2c_ram->rstate, 0);
163 out_be32(&i2c_ram->rdp, 0);
164 out_be16(&i2c_ram->rbptr, 0);
165 out_be16(&i2c_ram->rbc, 0);
166 out_be32(&i2c_ram->rxtmp, 0);
167 out_be32(&i2c_ram->tstate, 0);
168 out_be32(&i2c_ram->tdp, 0);
169 out_be16(&i2c_ram->tbptr, 0);
170 out_be16(&i2c_ram->tbc, 0);
171 out_be32(&i2c_ram->txtmp, 0);
172}
173
174static void cpm_i2c_force_close(struct i2c_adapter *adap)
175{
176 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
177 struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
178
179 dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");
180
181 cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);
182
183 out_8(&i2c_reg->i2cmr, 0x00); /* Disable all interrupts */
184 out_8(&i2c_reg->i2cer, 0xff);
185}
186
187static void cpm_i2c_parse_message(struct i2c_adapter *adap,
188 struct i2c_msg *pmsg, int num, int tx, int rx)
189{
190 cbd_t __iomem *tbdf;
191 cbd_t __iomem *rbdf;
192 u_char addr;
193 u_char *tb;
194 u_char *rb;
195 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
196
197 tbdf = cpm->tbase + tx;
198 rbdf = cpm->rbase + rx;
199
200 addr = i2c_8bit_addr_from_msg(pmsg);
201
202 tb = cpm->txbuf[tx];
203 rb = cpm->rxbuf[rx];
204
205 /* Align read buffer */
206 rb = (u_char *) (((ulong) rb + 1) & ~1);
207
208 tb[0] = addr; /* Device address byte w/rw flag */
209
210 out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
211 out_be16(&tbdf->cbd_sc, 0);
212
213 if (!(pmsg->flags & I2C_M_NOSTART))
214 setbits16(&tbdf->cbd_sc, BD_I2C_START);
215
216 if (tx + 1 == num)
217 setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);
218
219 if (pmsg->flags & I2C_M_RD) {
220 /*
221 * To read, we need an empty buffer of the proper length.
222 * All that is used is the first byte for address, the remainder
223 * is just used for timing (and doesn't really have to exist).
224 */
225
226 dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);
227
228 out_be16(&rbdf->cbd_datlen, 0);
229 out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
230
231 if (rx + 1 == CPM_MAXBD)
232 setbits16(&rbdf->cbd_sc, BD_SC_WRAP);
233
234 eieio();
235 setbits16(&tbdf->cbd_sc, BD_SC_READY);
236 } else {
237 dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr);
238
239 memcpy(tb+1, pmsg->buf, pmsg->len);
240
241 eieio();
242 setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
243 }
244}
245
246static int cpm_i2c_check_message(struct i2c_adapter *adap,
247 struct i2c_msg *pmsg, int tx, int rx)
248{
249 cbd_t __iomem *tbdf;
250 cbd_t __iomem *rbdf;
251 u_char *tb;
252 u_char *rb;
253 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
254
255 tbdf = cpm->tbase + tx;
256 rbdf = cpm->rbase + rx;
257
258 tb = cpm->txbuf[tx];
259 rb = cpm->rxbuf[rx];
260
261 /* Align read buffer */
262 rb = (u_char *) (((uint) rb + 1) & ~1);
263
264 eieio();
265 if (pmsg->flags & I2C_M_RD) {
266 dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
267 in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));
268
269 if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
270 dev_dbg(&adap->dev, "I2C read; No ack\n");
271 return -ENXIO;
272 }
273 if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
274 dev_err(&adap->dev,
275 "I2C read; complete but rbuf empty\n");
276 return -EREMOTEIO;
277 }
278 if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
279 dev_err(&adap->dev, "I2C read; Overrun\n");
280 return -EREMOTEIO;
281 }
282 memcpy(pmsg->buf, rb, pmsg->len);
283 } else {
284 dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
285 in_be16(&tbdf->cbd_sc));
286
287 if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
288 dev_dbg(&adap->dev, "I2C write; No ack\n");
289 return -ENXIO;
290 }
291 if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
292 dev_err(&adap->dev, "I2C write; Underrun\n");
293 return -EIO;
294 }
295 if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
296 dev_err(&adap->dev, "I2C write; Collision\n");
297 return -EIO;
298 }
299 }
300 return 0;
301}
302
303static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
304{
305 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
306 struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
307 struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
308 struct i2c_msg *pmsg;
309 int ret;
310 int tptr;
311 int rptr;
312 cbd_t __iomem *tbdf;
313 cbd_t __iomem *rbdf;
314
315 /* Reset to use first buffer */
316 out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
317 out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
318
319 tbdf = cpm->tbase;
320 rbdf = cpm->rbase;
321
322 tptr = 0;
323 rptr = 0;
324
325 /*
326 * If there was a collision in the last i2c transaction,
327 * Set I2COM_MASTER as it was cleared during collision.
328 */
329 if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
330 out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);
331 }
332
333 while (tptr < num) {
334 pmsg = &msgs[tptr];
335 dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
336
337 cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
338 if (pmsg->flags & I2C_M_RD)
339 rptr++;
340 tptr++;
341 }
342 /* Start transfer now */
343 /* Enable RX/TX/Error interupts */
344 out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB);
345 out_8(&i2c_reg->i2cer, 0xff); /* Clear interrupt status */
346 /* Chip bug, set enable here */
347 setbits8(&i2c_reg->i2mod, I2MOD_EN); /* Enable */
348 /* Begin transmission */
349 setbits8(&i2c_reg->i2com, I2COM_START);
350
351 tptr = 0;
352 rptr = 0;
353
354 while (tptr < num) {
355 /* Check for outstanding messages */
356 dev_dbg(&adap->dev, "test ready.\n");
357 pmsg = &msgs[tptr];
358 if (pmsg->flags & I2C_M_RD)
359 ret = wait_event_timeout(cpm->i2c_wait,
360 (in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||
361 !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
362 1 * HZ);
363 else
364 ret = wait_event_timeout(cpm->i2c_wait,
365 !(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
366 1 * HZ);
367 if (ret == 0) {
368 ret = -EREMOTEIO;
369 dev_err(&adap->dev, "I2C transfer: timeout\n");
370 goto out_err;
371 }
372 if (ret > 0) {
373 dev_dbg(&adap->dev, "ready.\n");
374 ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
375 tptr++;
376 if (pmsg->flags & I2C_M_RD)
377 rptr++;
378 if (ret)
379 goto out_err;
380 }
381 }
382#ifdef I2C_CHIP_ERRATA
383 /*
384 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
385 * Disabling I2C too early may cause too short stop condition
386 */
387 udelay(4);
388 clrbits8(&i2c_reg->i2mod, I2MOD_EN);
389#endif
390 return (num);
391
392out_err:
393 cpm_i2c_force_close(adap);
394#ifdef I2C_CHIP_ERRATA
395 /*
396 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
397 */
398 clrbits8(&i2c_reg->i2mod, I2MOD_EN);
399#endif
400 return ret;
401}
402
403static u32 cpm_i2c_func(struct i2c_adapter *adap)
404{
405 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
406}
407
408/* -----exported algorithm data: ------------------------------------- */
409
410static const struct i2c_algorithm cpm_i2c_algo = {
411 .master_xfer = cpm_i2c_xfer,
412 .functionality = cpm_i2c_func,
413};
414
415/* CPM_MAX_READ is also limiting writes according to the code! */
416static const struct i2c_adapter_quirks cpm_i2c_quirks = {
417 .max_num_msgs = CPM_MAXBD,
418 .max_read_len = CPM_MAX_READ,
419 .max_write_len = CPM_MAX_READ,
420};
421
422static const struct i2c_adapter cpm_ops = {
423 .owner = THIS_MODULE,
424 .name = "i2c-cpm",
425 .algo = &cpm_i2c_algo,
426 .quirks = &cpm_i2c_quirks,
427};
428
429static int cpm_i2c_setup(struct cpm_i2c *cpm)
430{
431 struct platform_device *ofdev = cpm->ofdev;
432 const u32 *data;
433 int len, ret, i;
434 void __iomem *i2c_base;
435 cbd_t __iomem *tbdf;
436 cbd_t __iomem *rbdf;
437 unsigned char brg;
438
439 dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");
440
441 init_waitqueue_head(&cpm->i2c_wait);
442
443 cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
444 if (!cpm->irq)
445 return -EINVAL;
446
447 /* Install interrupt handler. */
448 ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
449 &cpm->adap);
450 if (ret)
451 return ret;
452
453 /* I2C parameter RAM */
454 i2c_base = of_iomap(ofdev->dev.of_node, 1);
455 if (i2c_base == NULL) {
456 ret = -EINVAL;
457 goto out_irq;
458 }
459
460 if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) {
461
462 /* Check for and use a microcode relocation patch. */
463 cpm->i2c_ram = i2c_base;
464 cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);
465
466 /*
467 * Maybe should use cpm_muram_alloc instead of hardcoding
468 * this in micropatch.c
469 */
470 if (cpm->i2c_addr) {
471 cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
472 iounmap(i2c_base);
473 }
474
475 cpm->version = 1;
476
477 } else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) {
478 cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
479 cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
480 out_be16(i2c_base, cpm->i2c_addr);
481 iounmap(i2c_base);
482
483 cpm->version = 2;
484
485 } else {
486 iounmap(i2c_base);
487 ret = -EINVAL;
488 goto out_irq;
489 }
490
491 /* I2C control/status registers */
492 cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0);
493 if (cpm->i2c_reg == NULL) {
494 ret = -EINVAL;
495 goto out_ram;
496 }
497
498 data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
499 if (!data || len != 4) {
500 ret = -EINVAL;
501 goto out_reg;
502 }
503 cpm->cp_command = *data;
504
505 data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len);
506 if (data && len == 4)
507 cpm->adap.class = *data;
508
509 data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len);
510 if (data && len == 4)
511 cpm->freq = *data;
512 else
513 cpm->freq = 60000; /* use 60kHz i2c clock by default */
514
515 /*
516 * Allocate space for CPM_MAXBD transmit and receive buffer
517 * descriptors in the DP ram.
518 */
519 cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
520 if (!cpm->dp_addr) {
521 ret = -ENOMEM;
522 goto out_reg;
523 }
524
525 cpm->tbase = cpm_muram_addr(cpm->dp_addr);
526 cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);
527
528 /* Allocate TX and RX buffers */
529
530 tbdf = cpm->tbase;
531 rbdf = cpm->rbase;
532
533 for (i = 0; i < CPM_MAXBD; i++) {
534 cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
535 CPM_MAX_READ + 1,
536 &cpm->rxdma[i], GFP_KERNEL);
537 if (!cpm->rxbuf[i]) {
538 ret = -ENOMEM;
539 goto out_muram;
540 }
541 out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));
542
543 cpm->txbuf[i] = (unsigned char *)dma_alloc_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, &cpm->txdma[i], GFP_KERNEL);
544 if (!cpm->txbuf[i]) {
545 ret = -ENOMEM;
546 goto out_muram;
547 }
548 out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
549 }
550
551 /* Initialize Tx/Rx parameters. */
552
553 cpm_reset_i2c_params(cpm);
554
555 dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
556 cpm->i2c_ram, cpm->i2c_addr, cpm->freq);
557 dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
558 (u8 __iomem *)cpm->tbase - DPRAM_BASE,
559 (u8 __iomem *)cpm->rbase - DPRAM_BASE);
560
561 cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);
562
563 /*
564 * Select an invalid address. Just make sure we don't use loopback mode
565 */
566 out_8(&cpm->i2c_reg->i2add, 0x7f << 1);
567
568 /*
569 * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
570 * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
571 * the actual i2c bus frequency.
572 */
573 brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
574 out_8(&cpm->i2c_reg->i2brg, brg);
575
576 out_8(&cpm->i2c_reg->i2mod, 0x00);
577 out_8(&cpm->i2c_reg->i2com, I2COM_MASTER); /* Master mode */
578
579 /* Disable interrupts. */
580 out_8(&cpm->i2c_reg->i2cmr, 0);
581 out_8(&cpm->i2c_reg->i2cer, 0xff);
582
583 return 0;
584
585out_muram:
586 for (i = 0; i < CPM_MAXBD; i++) {
587 if (cpm->rxbuf[i])
588 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
589 cpm->rxbuf[i], cpm->rxdma[i]);
590 if (cpm->txbuf[i])
591 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
592 cpm->txbuf[i], cpm->txdma[i]);
593 }
594 cpm_muram_free(cpm->dp_addr);
595out_reg:
596 iounmap(cpm->i2c_reg);
597out_ram:
598 if ((cpm->version == 1) && (!cpm->i2c_addr))
599 iounmap(cpm->i2c_ram);
600 if (cpm->version == 2)
601 cpm_muram_free(cpm->i2c_addr);
602out_irq:
603 free_irq(cpm->irq, &cpm->adap);
604 return ret;
605}
606
607static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
608{
609 int i;
610
611 /* Shut down I2C. */
612 clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);
613
614 /* Disable interrupts */
615 out_8(&cpm->i2c_reg->i2cmr, 0);
616 out_8(&cpm->i2c_reg->i2cer, 0xff);
617
618 free_irq(cpm->irq, &cpm->adap);
619
620 /* Free all memory */
621 for (i = 0; i < CPM_MAXBD; i++) {
622 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
623 cpm->rxbuf[i], cpm->rxdma[i]);
624 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
625 cpm->txbuf[i], cpm->txdma[i]);
626 }
627
628 cpm_muram_free(cpm->dp_addr);
629 iounmap(cpm->i2c_reg);
630
631 if ((cpm->version == 1) && (!cpm->i2c_addr))
632 iounmap(cpm->i2c_ram);
633 if (cpm->version == 2)
634 cpm_muram_free(cpm->i2c_addr);
635}
636
637static int cpm_i2c_probe(struct platform_device *ofdev)
638{
639 int result, len;
640 struct cpm_i2c *cpm;
641 const u32 *data;
642
643 cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
644 if (!cpm)
645 return -ENOMEM;
646
647 cpm->ofdev = ofdev;
648
649 platform_set_drvdata(ofdev, cpm);
650
651 cpm->adap = cpm_ops;
652 i2c_set_adapdata(&cpm->adap, cpm);
653 cpm->adap.dev.parent = &ofdev->dev;
654 cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node);
655
656 result = cpm_i2c_setup(cpm);
657 if (result) {
658 dev_err(&ofdev->dev, "Unable to init hardware\n");
659 goto out_free;
660 }
661
662 /* register new adapter to i2c module... */
663
664 data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
665 cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1;
666 result = i2c_add_numbered_adapter(&cpm->adap);
667
668 if (result < 0)
669 goto out_shut;
670
671 dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
672 cpm->adap.name);
673
674 return 0;
675out_shut:
676 cpm_i2c_shutdown(cpm);
677out_free:
678 kfree(cpm);
679
680 return result;
681}
682
683static int cpm_i2c_remove(struct platform_device *ofdev)
684{
685 struct cpm_i2c *cpm = platform_get_drvdata(ofdev);
686
687 i2c_del_adapter(&cpm->adap);
688
689 cpm_i2c_shutdown(cpm);
690
691 kfree(cpm);
692
693 return 0;
694}
695
696static const struct of_device_id cpm_i2c_match[] = {
697 {
698 .compatible = "fsl,cpm1-i2c",
699 },
700 {
701 .compatible = "fsl,cpm2-i2c",
702 },
703 {},
704};
705
706MODULE_DEVICE_TABLE(of, cpm_i2c_match);
707
708static struct platform_driver cpm_i2c_driver = {
709 .probe = cpm_i2c_probe,
710 .remove = cpm_i2c_remove,
711 .driver = {
712 .name = "fsl-i2c-cpm",
713 .of_match_table = cpm_i2c_match,
714 },
715};
716
717module_platform_driver(cpm_i2c_driver);
718
719MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
720MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
721MODULE_LICENSE("GPL");