xref: /openbmc/linux/drivers/i2c/busses/i2c-cpm.c (revision 37be287c)
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/interrupt.h>
37 #include <linux/errno.h>
38 #include <linux/stddef.h>
39 #include <linux/i2c.h>
40 #include <linux/io.h>
41 #include <linux/dma-mapping.h>
42 #include <linux/of_device.h>
43 #include <linux/of_platform.h>
44 #include <sysdev/fsl_soc.h>
45 #include <asm/cpm.h>
46 
47 /* Try to define this if you have an older CPU (earlier than rev D4) */
48 /* However, better use a GPIO based bitbang driver in this case :/   */
49 #undef	I2C_CHIP_ERRATA
50 
51 #define CPM_MAX_READ    513
52 #define CPM_MAXBD       4
53 
54 #define I2C_EB			(0x10) /* Big endian mode */
55 #define I2C_EB_CPM2		(0x30) /* Big endian mode, memory snoop */
56 
57 #define DPRAM_BASE		((u8 __iomem __force *)cpm_muram_addr(0))
58 
59 /* I2C parameter RAM. */
60 struct i2c_ram {
61 	ushort  rbase;		/* Rx Buffer descriptor base address */
62 	ushort  tbase;		/* Tx Buffer descriptor base address */
63 	u_char  rfcr;		/* Rx function code */
64 	u_char  tfcr;		/* Tx function code */
65 	ushort  mrblr;		/* Max receive buffer length */
66 	uint    rstate;		/* Internal */
67 	uint    rdp;		/* Internal */
68 	ushort  rbptr;		/* Rx Buffer descriptor pointer */
69 	ushort  rbc;		/* Internal */
70 	uint    rxtmp;		/* Internal */
71 	uint    tstate;		/* Internal */
72 	uint    tdp;		/* Internal */
73 	ushort  tbptr;		/* Tx Buffer descriptor pointer */
74 	ushort  tbc;		/* Internal */
75 	uint    txtmp;		/* Internal */
76 	char    res1[4];	/* Reserved */
77 	ushort  rpbase;		/* Relocation pointer */
78 	char    res2[2];	/* Reserved */
79 };
80 
81 #define I2COM_START	0x80
82 #define I2COM_MASTER	0x01
83 #define I2CER_TXE	0x10
84 #define I2CER_BUSY	0x04
85 #define I2CER_TXB	0x02
86 #define I2CER_RXB	0x01
87 #define I2MOD_EN	0x01
88 
89 /* I2C Registers */
90 struct i2c_reg {
91 	u8	i2mod;
92 	u8	res1[3];
93 	u8	i2add;
94 	u8	res2[3];
95 	u8	i2brg;
96 	u8	res3[3];
97 	u8	i2com;
98 	u8	res4[3];
99 	u8	i2cer;
100 	u8	res5[3];
101 	u8	i2cmr;
102 };
103 
104 struct cpm_i2c {
105 	char *base;
106 	struct platform_device *ofdev;
107 	struct i2c_adapter adap;
108 	uint dp_addr;
109 	int version; /* CPM1=1, CPM2=2 */
110 	int irq;
111 	int cp_command;
112 	int freq;
113 	struct i2c_reg __iomem *i2c_reg;
114 	struct i2c_ram __iomem *i2c_ram;
115 	u16 i2c_addr;
116 	wait_queue_head_t i2c_wait;
117 	cbd_t __iomem *tbase;
118 	cbd_t __iomem *rbase;
119 	u_char *txbuf[CPM_MAXBD];
120 	u_char *rxbuf[CPM_MAXBD];
121 	u32 txdma[CPM_MAXBD];
122 	u32 rxdma[CPM_MAXBD];
123 };
124 
125 static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
126 {
127 	struct cpm_i2c *cpm;
128 	struct i2c_reg __iomem *i2c_reg;
129 	struct i2c_adapter *adap = dev_id;
130 	int i;
131 
132 	cpm = i2c_get_adapdata(dev_id);
133 	i2c_reg = cpm->i2c_reg;
134 
135 	/* Clear interrupt. */
136 	i = in_8(&i2c_reg->i2cer);
137 	out_8(&i2c_reg->i2cer, i);
138 
139 	dev_dbg(&adap->dev, "Interrupt: %x\n", i);
140 
141 	wake_up(&cpm->i2c_wait);
142 
143 	return i ? IRQ_HANDLED : IRQ_NONE;
144 }
145 
146 static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
147 {
148 	struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
149 
150 	/* Set up the I2C parameters in the parameter ram. */
151 	out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
152 	out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);
153 
154 	if (cpm->version == 1) {
155 		out_8(&i2c_ram->tfcr, I2C_EB);
156 		out_8(&i2c_ram->rfcr, I2C_EB);
157 	} else {
158 		out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
159 		out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
160 	}
161 
162 	out_be16(&i2c_ram->mrblr, CPM_MAX_READ);
163 
164 	out_be32(&i2c_ram->rstate, 0);
165 	out_be32(&i2c_ram->rdp, 0);
166 	out_be16(&i2c_ram->rbptr, 0);
167 	out_be16(&i2c_ram->rbc, 0);
168 	out_be32(&i2c_ram->rxtmp, 0);
169 	out_be32(&i2c_ram->tstate, 0);
170 	out_be32(&i2c_ram->tdp, 0);
171 	out_be16(&i2c_ram->tbptr, 0);
172 	out_be16(&i2c_ram->tbc, 0);
173 	out_be32(&i2c_ram->txtmp, 0);
174 }
175 
176 static void cpm_i2c_force_close(struct i2c_adapter *adap)
177 {
178 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
179 	struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
180 
181 	dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");
182 
183 	cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);
184 
185 	out_8(&i2c_reg->i2cmr, 0x00);	/* Disable all interrupts */
186 	out_8(&i2c_reg->i2cer, 0xff);
187 }
188 
189 static void cpm_i2c_parse_message(struct i2c_adapter *adap,
190 	struct i2c_msg *pmsg, int num, int tx, int rx)
191 {
192 	cbd_t __iomem *tbdf;
193 	cbd_t __iomem *rbdf;
194 	u_char addr;
195 	u_char *tb;
196 	u_char *rb;
197 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
198 
199 	tbdf = cpm->tbase + tx;
200 	rbdf = cpm->rbase + rx;
201 
202 	addr = pmsg->addr << 1;
203 	if (pmsg->flags & I2C_M_RD)
204 		addr |= 1;
205 
206 	tb = cpm->txbuf[tx];
207 	rb = cpm->rxbuf[rx];
208 
209 	/* Align read buffer */
210 	rb = (u_char *) (((ulong) rb + 1) & ~1);
211 
212 	tb[0] = addr;		/* Device address byte w/rw flag */
213 
214 	out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
215 	out_be16(&tbdf->cbd_sc, 0);
216 
217 	if (!(pmsg->flags & I2C_M_NOSTART))
218 		setbits16(&tbdf->cbd_sc, BD_I2C_START);
219 
220 	if (tx + 1 == num)
221 		setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);
222 
223 	if (pmsg->flags & I2C_M_RD) {
224 		/*
225 		 * To read, we need an empty buffer of the proper length.
226 		 * All that is used is the first byte for address, the remainder
227 		 * is just used for timing (and doesn't really have to exist).
228 		 */
229 
230 		dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);
231 
232 		out_be16(&rbdf->cbd_datlen, 0);
233 		out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
234 
235 		if (rx + 1 == CPM_MAXBD)
236 			setbits16(&rbdf->cbd_sc, BD_SC_WRAP);
237 
238 		eieio();
239 		setbits16(&tbdf->cbd_sc, BD_SC_READY);
240 	} else {
241 		dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr);
242 
243 		memcpy(tb+1, pmsg->buf, pmsg->len);
244 
245 		eieio();
246 		setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
247 	}
248 }
249 
250 static int cpm_i2c_check_message(struct i2c_adapter *adap,
251 	struct i2c_msg *pmsg, int tx, int rx)
252 {
253 	cbd_t __iomem *tbdf;
254 	cbd_t __iomem *rbdf;
255 	u_char *tb;
256 	u_char *rb;
257 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
258 
259 	tbdf = cpm->tbase + tx;
260 	rbdf = cpm->rbase + rx;
261 
262 	tb = cpm->txbuf[tx];
263 	rb = cpm->rxbuf[rx];
264 
265 	/* Align read buffer */
266 	rb = (u_char *) (((uint) rb + 1) & ~1);
267 
268 	eieio();
269 	if (pmsg->flags & I2C_M_RD) {
270 		dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
271 			in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));
272 
273 		if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
274 			dev_dbg(&adap->dev, "I2C read; No ack\n");
275 			return -ENXIO;
276 		}
277 		if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
278 			dev_err(&adap->dev,
279 				"I2C read; complete but rbuf empty\n");
280 			return -EREMOTEIO;
281 		}
282 		if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
283 			dev_err(&adap->dev, "I2C read; Overrun\n");
284 			return -EREMOTEIO;
285 		}
286 		memcpy(pmsg->buf, rb, pmsg->len);
287 	} else {
288 		dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
289 			in_be16(&tbdf->cbd_sc));
290 
291 		if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
292 			dev_dbg(&adap->dev, "I2C write; No ack\n");
293 			return -ENXIO;
294 		}
295 		if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
296 			dev_err(&adap->dev, "I2C write; Underrun\n");
297 			return -EIO;
298 		}
299 		if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
300 			dev_err(&adap->dev, "I2C write; Collision\n");
301 			return -EIO;
302 		}
303 	}
304 	return 0;
305 }
306 
307 static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
308 {
309 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
310 	struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
311 	struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
312 	struct i2c_msg *pmsg;
313 	int ret, i;
314 	int tptr;
315 	int rptr;
316 	cbd_t __iomem *tbdf;
317 	cbd_t __iomem *rbdf;
318 
319 	if (num > CPM_MAXBD)
320 		return -EINVAL;
321 
322 	/* Check if we have any oversized READ requests */
323 	for (i = 0; i < num; i++) {
324 		pmsg = &msgs[i];
325 		if (pmsg->len >= CPM_MAX_READ)
326 			return -EINVAL;
327 	}
328 
329 	/* Reset to use first buffer */
330 	out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
331 	out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
332 
333 	tbdf = cpm->tbase;
334 	rbdf = cpm->rbase;
335 
336 	tptr = 0;
337 	rptr = 0;
338 
339 	/*
340 	 * If there was a collision in the last i2c transaction,
341 	 * Set I2COM_MASTER as it was cleared during collision.
342 	 */
343 	if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
344 		out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);
345 	}
346 
347 	while (tptr < num) {
348 		pmsg = &msgs[tptr];
349 		dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
350 
351 		cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
352 		if (pmsg->flags & I2C_M_RD)
353 			rptr++;
354 		tptr++;
355 	}
356 	/* Start transfer now */
357 	/* Enable RX/TX/Error interupts */
358 	out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB);
359 	out_8(&i2c_reg->i2cer, 0xff);	/* Clear interrupt status */
360 	/* Chip bug, set enable here */
361 	setbits8(&i2c_reg->i2mod, I2MOD_EN);	/* Enable */
362 	/* Begin transmission */
363 	setbits8(&i2c_reg->i2com, I2COM_START);
364 
365 	tptr = 0;
366 	rptr = 0;
367 
368 	while (tptr < num) {
369 		/* Check for outstanding messages */
370 		dev_dbg(&adap->dev, "test ready.\n");
371 		pmsg = &msgs[tptr];
372 		if (pmsg->flags & I2C_M_RD)
373 			ret = wait_event_timeout(cpm->i2c_wait,
374 				(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||
375 				!(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
376 				1 * HZ);
377 		else
378 			ret = wait_event_timeout(cpm->i2c_wait,
379 				!(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
380 				1 * HZ);
381 		if (ret == 0) {
382 			ret = -EREMOTEIO;
383 			dev_err(&adap->dev, "I2C transfer: timeout\n");
384 			goto out_err;
385 		}
386 		if (ret > 0) {
387 			dev_dbg(&adap->dev, "ready.\n");
388 			ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
389 			tptr++;
390 			if (pmsg->flags & I2C_M_RD)
391 				rptr++;
392 			if (ret)
393 				goto out_err;
394 		}
395 	}
396 #ifdef I2C_CHIP_ERRATA
397 	/*
398 	 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
399 	 * Disabling I2C too early may cause too short stop condition
400 	 */
401 	udelay(4);
402 	clrbits8(&i2c_reg->i2mod, I2MOD_EN);
403 #endif
404 	return (num);
405 
406 out_err:
407 	cpm_i2c_force_close(adap);
408 #ifdef I2C_CHIP_ERRATA
409 	/*
410 	 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
411 	 */
412 	clrbits8(&i2c_reg->i2mod, I2MOD_EN);
413 #endif
414 	return ret;
415 }
416 
417 static u32 cpm_i2c_func(struct i2c_adapter *adap)
418 {
419 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
420 }
421 
422 /* -----exported algorithm data: -------------------------------------	*/
423 
424 static const struct i2c_algorithm cpm_i2c_algo = {
425 	.master_xfer = cpm_i2c_xfer,
426 	.functionality = cpm_i2c_func,
427 };
428 
429 static const struct i2c_adapter cpm_ops = {
430 	.owner		= THIS_MODULE,
431 	.name		= "i2c-cpm",
432 	.algo		= &cpm_i2c_algo,
433 };
434 
435 static int cpm_i2c_setup(struct cpm_i2c *cpm)
436 {
437 	struct platform_device *ofdev = cpm->ofdev;
438 	const u32 *data;
439 	int len, ret, i;
440 	void __iomem *i2c_base;
441 	cbd_t __iomem *tbdf;
442 	cbd_t __iomem *rbdf;
443 	unsigned char brg;
444 
445 	dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");
446 
447 	init_waitqueue_head(&cpm->i2c_wait);
448 
449 	cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
450 	if (!cpm->irq)
451 		return -EINVAL;
452 
453 	/* Install interrupt handler. */
454 	ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
455 			  &cpm->adap);
456 	if (ret)
457 		return ret;
458 
459 	/* I2C parameter RAM */
460 	i2c_base = of_iomap(ofdev->dev.of_node, 1);
461 	if (i2c_base == NULL) {
462 		ret = -EINVAL;
463 		goto out_irq;
464 	}
465 
466 	if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) {
467 
468 		/* Check for and use a microcode relocation patch. */
469 		cpm->i2c_ram = i2c_base;
470 		cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);
471 
472 		/*
473 		 * Maybe should use cpm_muram_alloc instead of hardcoding
474 		 * this in micropatch.c
475 		 */
476 		if (cpm->i2c_addr) {
477 			cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
478 			iounmap(i2c_base);
479 		}
480 
481 		cpm->version = 1;
482 
483 	} else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) {
484 		cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
485 		cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
486 		out_be16(i2c_base, cpm->i2c_addr);
487 		iounmap(i2c_base);
488 
489 		cpm->version = 2;
490 
491 	} else {
492 		iounmap(i2c_base);
493 		ret = -EINVAL;
494 		goto out_irq;
495 	}
496 
497 	/* I2C control/status registers */
498 	cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0);
499 	if (cpm->i2c_reg == NULL) {
500 		ret = -EINVAL;
501 		goto out_ram;
502 	}
503 
504 	data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
505 	if (!data || len != 4) {
506 		ret = -EINVAL;
507 		goto out_reg;
508 	}
509 	cpm->cp_command = *data;
510 
511 	data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len);
512 	if (data && len == 4)
513 		cpm->adap.class = *data;
514 
515 	data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len);
516 	if (data && len == 4)
517 		cpm->freq = *data;
518 	else
519 		cpm->freq = 60000; /* use 60kHz i2c clock by default */
520 
521 	/*
522 	 * Allocate space for CPM_MAXBD transmit and receive buffer
523 	 * descriptors in the DP ram.
524 	 */
525 	cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
526 	if (!cpm->dp_addr) {
527 		ret = -ENOMEM;
528 		goto out_reg;
529 	}
530 
531 	cpm->tbase = cpm_muram_addr(cpm->dp_addr);
532 	cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);
533 
534 	/* Allocate TX and RX buffers */
535 
536 	tbdf = cpm->tbase;
537 	rbdf = cpm->rbase;
538 
539 	for (i = 0; i < CPM_MAXBD; i++) {
540 		cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
541 						   CPM_MAX_READ + 1,
542 						   &cpm->rxdma[i], GFP_KERNEL);
543 		if (!cpm->rxbuf[i]) {
544 			ret = -ENOMEM;
545 			goto out_muram;
546 		}
547 		out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));
548 
549 		cpm->txbuf[i] = (unsigned char *)dma_alloc_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, &cpm->txdma[i], GFP_KERNEL);
550 		if (!cpm->txbuf[i]) {
551 			ret = -ENOMEM;
552 			goto out_muram;
553 		}
554 		out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
555 	}
556 
557 	/* Initialize Tx/Rx parameters. */
558 
559 	cpm_reset_i2c_params(cpm);
560 
561 	dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
562 		cpm->i2c_ram, cpm->i2c_addr, cpm->freq);
563 	dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
564 		(u8 __iomem *)cpm->tbase - DPRAM_BASE,
565 		(u8 __iomem *)cpm->rbase - DPRAM_BASE);
566 
567 	cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);
568 
569 	/*
570 	 * Select an invalid address. Just make sure we don't use loopback mode
571 	 */
572 	out_8(&cpm->i2c_reg->i2add, 0x7f << 1);
573 
574 	/*
575 	 * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
576 	 * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
577 	 * the actual i2c bus frequency.
578 	 */
579 	brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
580 	out_8(&cpm->i2c_reg->i2brg, brg);
581 
582 	out_8(&cpm->i2c_reg->i2mod, 0x00);
583 	out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);	/* Master mode */
584 
585 	/* Disable interrupts. */
586 	out_8(&cpm->i2c_reg->i2cmr, 0);
587 	out_8(&cpm->i2c_reg->i2cer, 0xff);
588 
589 	return 0;
590 
591 out_muram:
592 	for (i = 0; i < CPM_MAXBD; i++) {
593 		if (cpm->rxbuf[i])
594 			dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
595 				cpm->rxbuf[i], cpm->rxdma[i]);
596 		if (cpm->txbuf[i])
597 			dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
598 				cpm->txbuf[i], cpm->txdma[i]);
599 	}
600 	cpm_muram_free(cpm->dp_addr);
601 out_reg:
602 	iounmap(cpm->i2c_reg);
603 out_ram:
604 	if ((cpm->version == 1) && (!cpm->i2c_addr))
605 		iounmap(cpm->i2c_ram);
606 	if (cpm->version == 2)
607 		cpm_muram_free(cpm->i2c_addr);
608 out_irq:
609 	free_irq(cpm->irq, &cpm->adap);
610 	return ret;
611 }
612 
613 static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
614 {
615 	int i;
616 
617 	/* Shut down I2C. */
618 	clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);
619 
620 	/* Disable interrupts */
621 	out_8(&cpm->i2c_reg->i2cmr, 0);
622 	out_8(&cpm->i2c_reg->i2cer, 0xff);
623 
624 	free_irq(cpm->irq, &cpm->adap);
625 
626 	/* Free all memory */
627 	for (i = 0; i < CPM_MAXBD; i++) {
628 		dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
629 			cpm->rxbuf[i], cpm->rxdma[i]);
630 		dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
631 			cpm->txbuf[i], cpm->txdma[i]);
632 	}
633 
634 	cpm_muram_free(cpm->dp_addr);
635 	iounmap(cpm->i2c_reg);
636 
637 	if ((cpm->version == 1) && (!cpm->i2c_addr))
638 		iounmap(cpm->i2c_ram);
639 	if (cpm->version == 2)
640 		cpm_muram_free(cpm->i2c_addr);
641 }
642 
643 static int cpm_i2c_probe(struct platform_device *ofdev)
644 {
645 	int result, len;
646 	struct cpm_i2c *cpm;
647 	const u32 *data;
648 
649 	cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
650 	if (!cpm)
651 		return -ENOMEM;
652 
653 	cpm->ofdev = ofdev;
654 
655 	platform_set_drvdata(ofdev, cpm);
656 
657 	cpm->adap = cpm_ops;
658 	i2c_set_adapdata(&cpm->adap, cpm);
659 	cpm->adap.dev.parent = &ofdev->dev;
660 	cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node);
661 
662 	result = cpm_i2c_setup(cpm);
663 	if (result) {
664 		dev_err(&ofdev->dev, "Unable to init hardware\n");
665 		goto out_free;
666 	}
667 
668 	/* register new adapter to i2c module... */
669 
670 	data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
671 	cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1;
672 	result = i2c_add_numbered_adapter(&cpm->adap);
673 
674 	if (result < 0) {
675 		dev_err(&ofdev->dev, "Unable to register with I2C\n");
676 		goto out_shut;
677 	}
678 
679 	dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
680 		cpm->adap.name);
681 
682 	return 0;
683 out_shut:
684 	cpm_i2c_shutdown(cpm);
685 out_free:
686 	kfree(cpm);
687 
688 	return result;
689 }
690 
691 static int cpm_i2c_remove(struct platform_device *ofdev)
692 {
693 	struct cpm_i2c *cpm = platform_get_drvdata(ofdev);
694 
695 	i2c_del_adapter(&cpm->adap);
696 
697 	cpm_i2c_shutdown(cpm);
698 
699 	kfree(cpm);
700 
701 	return 0;
702 }
703 
704 static const struct of_device_id cpm_i2c_match[] = {
705 	{
706 		.compatible = "fsl,cpm1-i2c",
707 	},
708 	{
709 		.compatible = "fsl,cpm2-i2c",
710 	},
711 	{},
712 };
713 
714 MODULE_DEVICE_TABLE(of, cpm_i2c_match);
715 
716 static struct platform_driver cpm_i2c_driver = {
717 	.probe		= cpm_i2c_probe,
718 	.remove		= cpm_i2c_remove,
719 	.driver = {
720 		.name = "fsl-i2c-cpm",
721 		.owner = THIS_MODULE,
722 		.of_match_table = cpm_i2c_match,
723 	},
724 };
725 
726 module_platform_driver(cpm_i2c_driver);
727 
728 MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
729 MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
730 MODULE_LICENSE("GPL");
731