xref: /linux/drivers/i2c/busses/i2c-cpm.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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 	u32 txdma[CPM_MAXBD];
120 	u32 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 = 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 
248 static 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 
305 static 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 
394 out_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 
405 static 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 
412 static 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! */
418 static 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 
424 static 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 
431 static 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 
587 out_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);
597 out_reg:
598 	iounmap(cpm->i2c_reg);
599 out_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);
604 out_irq:
605 	free_irq(cpm->irq, &cpm->adap);
606 	return ret;
607 }
608 
609 static 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 
639 static 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;
679 out_shut:
680 	cpm_i2c_shutdown(cpm);
681 out_free:
682 	kfree(cpm);
683 
684 	return result;
685 }
686 
687 static 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 
700 static 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 
710 MODULE_DEVICE_TABLE(of, cpm_i2c_match);
711 
712 static 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 
721 module_platform_driver(cpm_i2c_driver);
722 
723 MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
724 MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
725 MODULE_LICENSE("GPL");
726