xref: /openbmc/linux/drivers/i2c/busses/i2c-cpm.c (revision 799a545b)
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. */
58 struct 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 */
88 struct 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 
102 struct 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 
123 static 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 
144 static 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 
174 static 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 
187 static 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 
246 static 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 
303 static 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 
392 out_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 
403 static 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 
410 static 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! */
416 static 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 
422 static 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 
429 static 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 
585 out_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);
595 out_reg:
596 	iounmap(cpm->i2c_reg);
597 out_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);
602 out_irq:
603 	free_irq(cpm->irq, &cpm->adap);
604 	return ret;
605 }
606 
607 static 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 
637 static 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 		dev_err(&ofdev->dev, "Unable to register with I2C\n");
670 		goto out_shut;
671 	}
672 
673 	dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
674 		cpm->adap.name);
675 
676 	return 0;
677 out_shut:
678 	cpm_i2c_shutdown(cpm);
679 out_free:
680 	kfree(cpm);
681 
682 	return result;
683 }
684 
685 static int cpm_i2c_remove(struct platform_device *ofdev)
686 {
687 	struct cpm_i2c *cpm = platform_get_drvdata(ofdev);
688 
689 	i2c_del_adapter(&cpm->adap);
690 
691 	cpm_i2c_shutdown(cpm);
692 
693 	kfree(cpm);
694 
695 	return 0;
696 }
697 
698 static const struct of_device_id cpm_i2c_match[] = {
699 	{
700 		.compatible = "fsl,cpm1-i2c",
701 	},
702 	{
703 		.compatible = "fsl,cpm2-i2c",
704 	},
705 	{},
706 };
707 
708 MODULE_DEVICE_TABLE(of, cpm_i2c_match);
709 
710 static struct platform_driver cpm_i2c_driver = {
711 	.probe		= cpm_i2c_probe,
712 	.remove		= cpm_i2c_remove,
713 	.driver = {
714 		.name = "fsl-i2c-cpm",
715 		.of_match_table = cpm_i2c_match,
716 	},
717 };
718 
719 module_platform_driver(cpm_i2c_driver);
720 
721 MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
722 MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
723 MODULE_LICENSE("GPL");
724