xref: /openbmc/linux/drivers/i2c/busses/i2c-cpm.c (revision 7b6d864b)
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  *  You should have received a copy of the GNU General Public License
28  *  along with this program; if not, write to the Free Software
29  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
30  */
31 
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/delay.h>
35 #include <linux/slab.h>
36 #include <linux/init.h>
37 #include <linux/interrupt.h>
38 #include <linux/errno.h>
39 #include <linux/stddef.h>
40 #include <linux/i2c.h>
41 #include <linux/io.h>
42 #include <linux/dma-mapping.h>
43 #include <linux/of_device.h>
44 #include <linux/of_platform.h>
45 #include <linux/of_i2c.h>
46 #include <sysdev/fsl_soc.h>
47 #include <asm/cpm.h>
48 
49 /* Try to define this if you have an older CPU (earlier than rev D4) */
50 /* However, better use a GPIO based bitbang driver in this case :/   */
51 #undef	I2C_CHIP_ERRATA
52 
53 #define CPM_MAX_READ    513
54 #define CPM_MAXBD       4
55 
56 #define I2C_EB			(0x10) /* Big endian mode */
57 #define I2C_EB_CPM2		(0x30) /* Big endian mode, memory snoop */
58 
59 #define DPRAM_BASE		((u8 __iomem __force *)cpm_muram_addr(0))
60 
61 /* I2C parameter RAM. */
62 struct i2c_ram {
63 	ushort  rbase;		/* Rx Buffer descriptor base address */
64 	ushort  tbase;		/* Tx Buffer descriptor base address */
65 	u_char  rfcr;		/* Rx function code */
66 	u_char  tfcr;		/* Tx function code */
67 	ushort  mrblr;		/* Max receive buffer length */
68 	uint    rstate;		/* Internal */
69 	uint    rdp;		/* Internal */
70 	ushort  rbptr;		/* Rx Buffer descriptor pointer */
71 	ushort  rbc;		/* Internal */
72 	uint    rxtmp;		/* Internal */
73 	uint    tstate;		/* Internal */
74 	uint    tdp;		/* Internal */
75 	ushort  tbptr;		/* Tx Buffer descriptor pointer */
76 	ushort  tbc;		/* Internal */
77 	uint    txtmp;		/* Internal */
78 	char    res1[4];	/* Reserved */
79 	ushort  rpbase;		/* Relocation pointer */
80 	char    res2[2];	/* Reserved */
81 };
82 
83 #define I2COM_START	0x80
84 #define I2COM_MASTER	0x01
85 #define I2CER_TXE	0x10
86 #define I2CER_BUSY	0x04
87 #define I2CER_TXB	0x02
88 #define I2CER_RXB	0x01
89 #define I2MOD_EN	0x01
90 
91 /* I2C Registers */
92 struct i2c_reg {
93 	u8	i2mod;
94 	u8	res1[3];
95 	u8	i2add;
96 	u8	res2[3];
97 	u8	i2brg;
98 	u8	res3[3];
99 	u8	i2com;
100 	u8	res4[3];
101 	u8	i2cer;
102 	u8	res5[3];
103 	u8	i2cmr;
104 };
105 
106 struct cpm_i2c {
107 	char *base;
108 	struct platform_device *ofdev;
109 	struct i2c_adapter adap;
110 	uint dp_addr;
111 	int version; /* CPM1=1, CPM2=2 */
112 	int irq;
113 	int cp_command;
114 	int freq;
115 	struct i2c_reg __iomem *i2c_reg;
116 	struct i2c_ram __iomem *i2c_ram;
117 	u16 i2c_addr;
118 	wait_queue_head_t i2c_wait;
119 	cbd_t __iomem *tbase;
120 	cbd_t __iomem *rbase;
121 	u_char *txbuf[CPM_MAXBD];
122 	u_char *rxbuf[CPM_MAXBD];
123 	u32 txdma[CPM_MAXBD];
124 	u32 rxdma[CPM_MAXBD];
125 };
126 
127 static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
128 {
129 	struct cpm_i2c *cpm;
130 	struct i2c_reg __iomem *i2c_reg;
131 	struct i2c_adapter *adap = dev_id;
132 	int i;
133 
134 	cpm = i2c_get_adapdata(dev_id);
135 	i2c_reg = cpm->i2c_reg;
136 
137 	/* Clear interrupt. */
138 	i = in_8(&i2c_reg->i2cer);
139 	out_8(&i2c_reg->i2cer, i);
140 
141 	dev_dbg(&adap->dev, "Interrupt: %x\n", i);
142 
143 	wake_up(&cpm->i2c_wait);
144 
145 	return i ? IRQ_HANDLED : IRQ_NONE;
146 }
147 
148 static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
149 {
150 	struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
151 
152 	/* Set up the I2C parameters in the parameter ram. */
153 	out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
154 	out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);
155 
156 	if (cpm->version == 1) {
157 		out_8(&i2c_ram->tfcr, I2C_EB);
158 		out_8(&i2c_ram->rfcr, I2C_EB);
159 	} else {
160 		out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
161 		out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
162 	}
163 
164 	out_be16(&i2c_ram->mrblr, CPM_MAX_READ);
165 
166 	out_be32(&i2c_ram->rstate, 0);
167 	out_be32(&i2c_ram->rdp, 0);
168 	out_be16(&i2c_ram->rbptr, 0);
169 	out_be16(&i2c_ram->rbc, 0);
170 	out_be32(&i2c_ram->rxtmp, 0);
171 	out_be32(&i2c_ram->tstate, 0);
172 	out_be32(&i2c_ram->tdp, 0);
173 	out_be16(&i2c_ram->tbptr, 0);
174 	out_be16(&i2c_ram->tbc, 0);
175 	out_be32(&i2c_ram->txtmp, 0);
176 }
177 
178 static void cpm_i2c_force_close(struct i2c_adapter *adap)
179 {
180 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
181 	struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
182 
183 	dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");
184 
185 	cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);
186 
187 	out_8(&i2c_reg->i2cmr, 0x00);	/* Disable all interrupts */
188 	out_8(&i2c_reg->i2cer, 0xff);
189 }
190 
191 static void cpm_i2c_parse_message(struct i2c_adapter *adap,
192 	struct i2c_msg *pmsg, int num, int tx, int rx)
193 {
194 	cbd_t __iomem *tbdf;
195 	cbd_t __iomem *rbdf;
196 	u_char addr;
197 	u_char *tb;
198 	u_char *rb;
199 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
200 
201 	tbdf = cpm->tbase + tx;
202 	rbdf = cpm->rbase + rx;
203 
204 	addr = pmsg->addr << 1;
205 	if (pmsg->flags & I2C_M_RD)
206 		addr |= 1;
207 
208 	tb = cpm->txbuf[tx];
209 	rb = cpm->rxbuf[rx];
210 
211 	/* Align read buffer */
212 	rb = (u_char *) (((ulong) rb + 1) & ~1);
213 
214 	tb[0] = addr;		/* Device address byte w/rw flag */
215 
216 	out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
217 	out_be16(&tbdf->cbd_sc, 0);
218 
219 	if (!(pmsg->flags & I2C_M_NOSTART))
220 		setbits16(&tbdf->cbd_sc, BD_I2C_START);
221 
222 	if (tx + 1 == num)
223 		setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);
224 
225 	if (pmsg->flags & I2C_M_RD) {
226 		/*
227 		 * To read, we need an empty buffer of the proper length.
228 		 * All that is used is the first byte for address, the remainder
229 		 * is just used for timing (and doesn't really have to exist).
230 		 */
231 
232 		dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);
233 
234 		out_be16(&rbdf->cbd_datlen, 0);
235 		out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
236 
237 		if (rx + 1 == CPM_MAXBD)
238 			setbits16(&rbdf->cbd_sc, BD_SC_WRAP);
239 
240 		eieio();
241 		setbits16(&tbdf->cbd_sc, BD_SC_READY);
242 	} else {
243 		dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr);
244 
245 		memcpy(tb+1, pmsg->buf, pmsg->len);
246 
247 		eieio();
248 		setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
249 	}
250 }
251 
252 static int cpm_i2c_check_message(struct i2c_adapter *adap,
253 	struct i2c_msg *pmsg, int tx, int rx)
254 {
255 	cbd_t __iomem *tbdf;
256 	cbd_t __iomem *rbdf;
257 	u_char *tb;
258 	u_char *rb;
259 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
260 
261 	tbdf = cpm->tbase + tx;
262 	rbdf = cpm->rbase + rx;
263 
264 	tb = cpm->txbuf[tx];
265 	rb = cpm->rxbuf[rx];
266 
267 	/* Align read buffer */
268 	rb = (u_char *) (((uint) rb + 1) & ~1);
269 
270 	eieio();
271 	if (pmsg->flags & I2C_M_RD) {
272 		dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
273 			in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));
274 
275 		if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
276 			dev_dbg(&adap->dev, "I2C read; No ack\n");
277 			return -ENXIO;
278 		}
279 		if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
280 			dev_err(&adap->dev,
281 				"I2C read; complete but rbuf empty\n");
282 			return -EREMOTEIO;
283 		}
284 		if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
285 			dev_err(&adap->dev, "I2C read; Overrun\n");
286 			return -EREMOTEIO;
287 		}
288 		memcpy(pmsg->buf, rb, pmsg->len);
289 	} else {
290 		dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
291 			in_be16(&tbdf->cbd_sc));
292 
293 		if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
294 			dev_dbg(&adap->dev, "I2C write; No ack\n");
295 			return -ENXIO;
296 		}
297 		if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
298 			dev_err(&adap->dev, "I2C write; Underrun\n");
299 			return -EIO;
300 		}
301 		if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
302 			dev_err(&adap->dev, "I2C write; Collision\n");
303 			return -EIO;
304 		}
305 	}
306 	return 0;
307 }
308 
309 static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
310 {
311 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
312 	struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
313 	struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
314 	struct i2c_msg *pmsg;
315 	int ret, i;
316 	int tptr;
317 	int rptr;
318 	cbd_t __iomem *tbdf;
319 	cbd_t __iomem *rbdf;
320 
321 	if (num > CPM_MAXBD)
322 		return -EINVAL;
323 
324 	/* Check if we have any oversized READ requests */
325 	for (i = 0; i < num; i++) {
326 		pmsg = &msgs[i];
327 		if (pmsg->len >= CPM_MAX_READ)
328 			return -EINVAL;
329 	}
330 
331 	/* Reset to use first buffer */
332 	out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
333 	out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
334 
335 	tbdf = cpm->tbase;
336 	rbdf = cpm->rbase;
337 
338 	tptr = 0;
339 	rptr = 0;
340 
341 	/*
342 	 * If there was a collision in the last i2c transaction,
343 	 * Set I2COM_MASTER as it was cleared during collision.
344 	 */
345 	if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
346 		out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);
347 	}
348 
349 	while (tptr < num) {
350 		pmsg = &msgs[tptr];
351 		dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
352 
353 		cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
354 		if (pmsg->flags & I2C_M_RD)
355 			rptr++;
356 		tptr++;
357 	}
358 	/* Start transfer now */
359 	/* Enable RX/TX/Error interupts */
360 	out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB);
361 	out_8(&i2c_reg->i2cer, 0xff);	/* Clear interrupt status */
362 	/* Chip bug, set enable here */
363 	setbits8(&i2c_reg->i2mod, I2MOD_EN);	/* Enable */
364 	/* Begin transmission */
365 	setbits8(&i2c_reg->i2com, I2COM_START);
366 
367 	tptr = 0;
368 	rptr = 0;
369 
370 	while (tptr < num) {
371 		/* Check for outstanding messages */
372 		dev_dbg(&adap->dev, "test ready.\n");
373 		pmsg = &msgs[tptr];
374 		if (pmsg->flags & I2C_M_RD)
375 			ret = wait_event_timeout(cpm->i2c_wait,
376 				(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||
377 				!(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
378 				1 * HZ);
379 		else
380 			ret = wait_event_timeout(cpm->i2c_wait,
381 				!(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
382 				1 * HZ);
383 		if (ret == 0) {
384 			ret = -EREMOTEIO;
385 			dev_err(&adap->dev, "I2C transfer: timeout\n");
386 			goto out_err;
387 		}
388 		if (ret > 0) {
389 			dev_dbg(&adap->dev, "ready.\n");
390 			ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
391 			tptr++;
392 			if (pmsg->flags & I2C_M_RD)
393 				rptr++;
394 			if (ret)
395 				goto out_err;
396 		}
397 	}
398 #ifdef I2C_CHIP_ERRATA
399 	/*
400 	 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
401 	 * Disabling I2C too early may cause too short stop condition
402 	 */
403 	udelay(4);
404 	clrbits8(&i2c_reg->i2mod, I2MOD_EN);
405 #endif
406 	return (num);
407 
408 out_err:
409 	cpm_i2c_force_close(adap);
410 #ifdef I2C_CHIP_ERRATA
411 	/*
412 	 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
413 	 */
414 	clrbits8(&i2c_reg->i2mod, I2MOD_EN);
415 #endif
416 	return ret;
417 }
418 
419 static u32 cpm_i2c_func(struct i2c_adapter *adap)
420 {
421 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
422 }
423 
424 /* -----exported algorithm data: -------------------------------------	*/
425 
426 static const struct i2c_algorithm cpm_i2c_algo = {
427 	.master_xfer = cpm_i2c_xfer,
428 	.functionality = cpm_i2c_func,
429 };
430 
431 static const struct i2c_adapter cpm_ops = {
432 	.owner		= THIS_MODULE,
433 	.name		= "i2c-cpm",
434 	.algo		= &cpm_i2c_algo,
435 };
436 
437 static int cpm_i2c_setup(struct cpm_i2c *cpm)
438 {
439 	struct platform_device *ofdev = cpm->ofdev;
440 	const u32 *data;
441 	int len, ret, i;
442 	void __iomem *i2c_base;
443 	cbd_t __iomem *tbdf;
444 	cbd_t __iomem *rbdf;
445 	unsigned char brg;
446 
447 	dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");
448 
449 	init_waitqueue_head(&cpm->i2c_wait);
450 
451 	cpm->irq = of_irq_to_resource(ofdev->dev.of_node, 0, NULL);
452 	if (!cpm->irq)
453 		return -EINVAL;
454 
455 	/* Install interrupt handler. */
456 	ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
457 			  &cpm->adap);
458 	if (ret)
459 		return ret;
460 
461 	/* I2C parameter RAM */
462 	i2c_base = of_iomap(ofdev->dev.of_node, 1);
463 	if (i2c_base == NULL) {
464 		ret = -EINVAL;
465 		goto out_irq;
466 	}
467 
468 	if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) {
469 
470 		/* Check for and use a microcode relocation patch. */
471 		cpm->i2c_ram = i2c_base;
472 		cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);
473 
474 		/*
475 		 * Maybe should use cpm_muram_alloc instead of hardcoding
476 		 * this in micropatch.c
477 		 */
478 		if (cpm->i2c_addr) {
479 			cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
480 			iounmap(i2c_base);
481 		}
482 
483 		cpm->version = 1;
484 
485 	} else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) {
486 		cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
487 		cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
488 		out_be16(i2c_base, cpm->i2c_addr);
489 		iounmap(i2c_base);
490 
491 		cpm->version = 2;
492 
493 	} else {
494 		iounmap(i2c_base);
495 		ret = -EINVAL;
496 		goto out_irq;
497 	}
498 
499 	/* I2C control/status registers */
500 	cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0);
501 	if (cpm->i2c_reg == NULL) {
502 		ret = -EINVAL;
503 		goto out_ram;
504 	}
505 
506 	data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
507 	if (!data || len != 4) {
508 		ret = -EINVAL;
509 		goto out_reg;
510 	}
511 	cpm->cp_command = *data;
512 
513 	data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len);
514 	if (data && len == 4)
515 		cpm->adap.class = *data;
516 
517 	data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len);
518 	if (data && len == 4)
519 		cpm->freq = *data;
520 	else
521 		cpm->freq = 60000; /* use 60kHz i2c clock by default */
522 
523 	/*
524 	 * Allocate space for CPM_MAXBD transmit and receive buffer
525 	 * descriptors in the DP ram.
526 	 */
527 	cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
528 	if (!cpm->dp_addr) {
529 		ret = -ENOMEM;
530 		goto out_reg;
531 	}
532 
533 	cpm->tbase = cpm_muram_addr(cpm->dp_addr);
534 	cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);
535 
536 	/* Allocate TX and RX buffers */
537 
538 	tbdf = cpm->tbase;
539 	rbdf = cpm->rbase;
540 
541 	for (i = 0; i < CPM_MAXBD; i++) {
542 		cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
543 						   CPM_MAX_READ + 1,
544 						   &cpm->rxdma[i], GFP_KERNEL);
545 		if (!cpm->rxbuf[i]) {
546 			ret = -ENOMEM;
547 			goto out_muram;
548 		}
549 		out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));
550 
551 		cpm->txbuf[i] = (unsigned char *)dma_alloc_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, &cpm->txdma[i], GFP_KERNEL);
552 		if (!cpm->txbuf[i]) {
553 			ret = -ENOMEM;
554 			goto out_muram;
555 		}
556 		out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
557 	}
558 
559 	/* Initialize Tx/Rx parameters. */
560 
561 	cpm_reset_i2c_params(cpm);
562 
563 	dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
564 		cpm->i2c_ram, cpm->i2c_addr, cpm->freq);
565 	dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
566 		(u8 __iomem *)cpm->tbase - DPRAM_BASE,
567 		(u8 __iomem *)cpm->rbase - DPRAM_BASE);
568 
569 	cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);
570 
571 	/*
572 	 * Select an invalid address. Just make sure we don't use loopback mode
573 	 */
574 	out_8(&cpm->i2c_reg->i2add, 0x7f << 1);
575 
576 	/*
577 	 * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
578 	 * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
579 	 * the actual i2c bus frequency.
580 	 */
581 	brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
582 	out_8(&cpm->i2c_reg->i2brg, brg);
583 
584 	out_8(&cpm->i2c_reg->i2mod, 0x00);
585 	out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);	/* Master mode */
586 
587 	/* Disable interrupts. */
588 	out_8(&cpm->i2c_reg->i2cmr, 0);
589 	out_8(&cpm->i2c_reg->i2cer, 0xff);
590 
591 	return 0;
592 
593 out_muram:
594 	for (i = 0; i < CPM_MAXBD; i++) {
595 		if (cpm->rxbuf[i])
596 			dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
597 				cpm->rxbuf[i], cpm->rxdma[i]);
598 		if (cpm->txbuf[i])
599 			dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
600 				cpm->txbuf[i], cpm->txdma[i]);
601 	}
602 	cpm_muram_free(cpm->dp_addr);
603 out_reg:
604 	iounmap(cpm->i2c_reg);
605 out_ram:
606 	if ((cpm->version == 1) && (!cpm->i2c_addr))
607 		iounmap(cpm->i2c_ram);
608 	if (cpm->version == 2)
609 		cpm_muram_free(cpm->i2c_addr);
610 out_irq:
611 	free_irq(cpm->irq, &cpm->adap);
612 	return ret;
613 }
614 
615 static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
616 {
617 	int i;
618 
619 	/* Shut down I2C. */
620 	clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);
621 
622 	/* Disable interrupts */
623 	out_8(&cpm->i2c_reg->i2cmr, 0);
624 	out_8(&cpm->i2c_reg->i2cer, 0xff);
625 
626 	free_irq(cpm->irq, &cpm->adap);
627 
628 	/* Free all memory */
629 	for (i = 0; i < CPM_MAXBD; i++) {
630 		dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
631 			cpm->rxbuf[i], cpm->rxdma[i]);
632 		dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
633 			cpm->txbuf[i], cpm->txdma[i]);
634 	}
635 
636 	cpm_muram_free(cpm->dp_addr);
637 	iounmap(cpm->i2c_reg);
638 
639 	if ((cpm->version == 1) && (!cpm->i2c_addr))
640 		iounmap(cpm->i2c_ram);
641 	if (cpm->version == 2)
642 		cpm_muram_free(cpm->i2c_addr);
643 }
644 
645 static int cpm_i2c_probe(struct platform_device *ofdev)
646 {
647 	int result, len;
648 	struct cpm_i2c *cpm;
649 	const u32 *data;
650 
651 	cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
652 	if (!cpm)
653 		return -ENOMEM;
654 
655 	cpm->ofdev = ofdev;
656 
657 	platform_set_drvdata(ofdev, cpm);
658 
659 	cpm->adap = cpm_ops;
660 	i2c_set_adapdata(&cpm->adap, cpm);
661 	cpm->adap.dev.parent = &ofdev->dev;
662 	cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node);
663 
664 	result = cpm_i2c_setup(cpm);
665 	if (result) {
666 		dev_err(&ofdev->dev, "Unable to init hardware\n");
667 		goto out_free;
668 	}
669 
670 	/* register new adapter to i2c module... */
671 
672 	data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
673 	cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1;
674 	result = i2c_add_numbered_adapter(&cpm->adap);
675 
676 	if (result < 0) {
677 		dev_err(&ofdev->dev, "Unable to register with I2C\n");
678 		goto out_shut;
679 	}
680 
681 	dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
682 		cpm->adap.name);
683 
684 	/*
685 	 * register OF I2C devices
686 	 */
687 	of_i2c_register_devices(&cpm->adap);
688 
689 	return 0;
690 out_shut:
691 	cpm_i2c_shutdown(cpm);
692 out_free:
693 	kfree(cpm);
694 
695 	return result;
696 }
697 
698 static int cpm_i2c_remove(struct platform_device *ofdev)
699 {
700 	struct cpm_i2c *cpm = platform_get_drvdata(ofdev);
701 
702 	i2c_del_adapter(&cpm->adap);
703 
704 	cpm_i2c_shutdown(cpm);
705 
706 	kfree(cpm);
707 
708 	return 0;
709 }
710 
711 static const struct of_device_id cpm_i2c_match[] = {
712 	{
713 		.compatible = "fsl,cpm1-i2c",
714 	},
715 	{
716 		.compatible = "fsl,cpm2-i2c",
717 	},
718 	{},
719 };
720 
721 MODULE_DEVICE_TABLE(of, cpm_i2c_match);
722 
723 static struct platform_driver cpm_i2c_driver = {
724 	.probe		= cpm_i2c_probe,
725 	.remove		= cpm_i2c_remove,
726 	.driver = {
727 		.name = "fsl-i2c-cpm",
728 		.owner = THIS_MODULE,
729 		.of_match_table = cpm_i2c_match,
730 	},
731 };
732 
733 module_platform_driver(cpm_i2c_driver);
734 
735 MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
736 MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
737 MODULE_LICENSE("GPL");
738