xref: /linux/drivers/i2c/busses/i2c-cpm.c (revision 22d55f02b8922a097cd4be1e2f131dfa7ef65901)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Freescale CPM1/CPM2 I2C interface.
4  * Copyright (c) 1999 Dan Malek (dmalek@jlc.net).
5  *
6  * moved into proper i2c interface;
7  * Brad Parker (brad@heeltoe.com)
8  *
9  * Parts from dbox2_i2c.c (cvs.tuxbox.org)
10  * (C) 2000-2001 Felix Domke (tmbinc@gmx.net), Gillem (htoa@gmx.net)
11  *
12  * (C) 2007 Montavista Software, Inc.
13  * Vitaly Bordug <vitb@kernel.crashing.org>
14  *
15  * Converted to of_platform_device. Renamed to i2c-cpm.c.
16  * (C) 2007,2008 Jochen Friedrich <jochen@scram.de>
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/delay.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/errno.h>
25 #include <linux/stddef.h>
26 #include <linux/i2c.h>
27 #include <linux/io.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/of_address.h>
30 #include <linux/of_device.h>
31 #include <linux/of_irq.h>
32 #include <linux/of_platform.h>
33 #include <sysdev/fsl_soc.h>
34 #include <asm/cpm.h>
35 
36 /* Try to define this if you have an older CPU (earlier than rev D4) */
37 /* However, better use a GPIO based bitbang driver in this case :/   */
38 #undef	I2C_CHIP_ERRATA
39 
40 #define CPM_MAX_READ    513
41 #define CPM_MAXBD       4
42 
43 #define I2C_EB			(0x10) /* Big endian mode */
44 #define I2C_EB_CPM2		(0x30) /* Big endian mode, memory snoop */
45 
46 #define DPRAM_BASE		((u8 __iomem __force *)cpm_muram_addr(0))
47 
48 /* I2C parameter RAM. */
49 struct i2c_ram {
50 	ushort  rbase;		/* Rx Buffer descriptor base address */
51 	ushort  tbase;		/* Tx Buffer descriptor base address */
52 	u_char  rfcr;		/* Rx function code */
53 	u_char  tfcr;		/* Tx function code */
54 	ushort  mrblr;		/* Max receive buffer length */
55 	uint    rstate;		/* Internal */
56 	uint    rdp;		/* Internal */
57 	ushort  rbptr;		/* Rx Buffer descriptor pointer */
58 	ushort  rbc;		/* Internal */
59 	uint    rxtmp;		/* Internal */
60 	uint    tstate;		/* Internal */
61 	uint    tdp;		/* Internal */
62 	ushort  tbptr;		/* Tx Buffer descriptor pointer */
63 	ushort  tbc;		/* Internal */
64 	uint    txtmp;		/* Internal */
65 	char    res1[4];	/* Reserved */
66 	ushort  rpbase;		/* Relocation pointer */
67 	char    res2[2];	/* Reserved */
68 };
69 
70 #define I2COM_START	0x80
71 #define I2COM_MASTER	0x01
72 #define I2CER_TXE	0x10
73 #define I2CER_BUSY	0x04
74 #define I2CER_TXB	0x02
75 #define I2CER_RXB	0x01
76 #define I2MOD_EN	0x01
77 
78 /* I2C Registers */
79 struct i2c_reg {
80 	u8	i2mod;
81 	u8	res1[3];
82 	u8	i2add;
83 	u8	res2[3];
84 	u8	i2brg;
85 	u8	res3[3];
86 	u8	i2com;
87 	u8	res4[3];
88 	u8	i2cer;
89 	u8	res5[3];
90 	u8	i2cmr;
91 };
92 
93 struct cpm_i2c {
94 	char *base;
95 	struct platform_device *ofdev;
96 	struct i2c_adapter adap;
97 	uint dp_addr;
98 	int version; /* CPM1=1, CPM2=2 */
99 	int irq;
100 	int cp_command;
101 	int freq;
102 	struct i2c_reg __iomem *i2c_reg;
103 	struct i2c_ram __iomem *i2c_ram;
104 	u16 i2c_addr;
105 	wait_queue_head_t i2c_wait;
106 	cbd_t __iomem *tbase;
107 	cbd_t __iomem *rbase;
108 	u_char *txbuf[CPM_MAXBD];
109 	u_char *rxbuf[CPM_MAXBD];
110 	dma_addr_t txdma[CPM_MAXBD];
111 	dma_addr_t rxdma[CPM_MAXBD];
112 };
113 
114 static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
115 {
116 	struct cpm_i2c *cpm;
117 	struct i2c_reg __iomem *i2c_reg;
118 	struct i2c_adapter *adap = dev_id;
119 	int i;
120 
121 	cpm = i2c_get_adapdata(dev_id);
122 	i2c_reg = cpm->i2c_reg;
123 
124 	/* Clear interrupt. */
125 	i = in_8(&i2c_reg->i2cer);
126 	out_8(&i2c_reg->i2cer, i);
127 
128 	dev_dbg(&adap->dev, "Interrupt: %x\n", i);
129 
130 	wake_up(&cpm->i2c_wait);
131 
132 	return i ? IRQ_HANDLED : IRQ_NONE;
133 }
134 
135 static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
136 {
137 	struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
138 
139 	/* Set up the I2C parameters in the parameter ram. */
140 	out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
141 	out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);
142 
143 	if (cpm->version == 1) {
144 		out_8(&i2c_ram->tfcr, I2C_EB);
145 		out_8(&i2c_ram->rfcr, I2C_EB);
146 	} else {
147 		out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
148 		out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
149 	}
150 
151 	out_be16(&i2c_ram->mrblr, CPM_MAX_READ);
152 
153 	out_be32(&i2c_ram->rstate, 0);
154 	out_be32(&i2c_ram->rdp, 0);
155 	out_be16(&i2c_ram->rbptr, 0);
156 	out_be16(&i2c_ram->rbc, 0);
157 	out_be32(&i2c_ram->rxtmp, 0);
158 	out_be32(&i2c_ram->tstate, 0);
159 	out_be32(&i2c_ram->tdp, 0);
160 	out_be16(&i2c_ram->tbptr, 0);
161 	out_be16(&i2c_ram->tbc, 0);
162 	out_be32(&i2c_ram->txtmp, 0);
163 }
164 
165 static void cpm_i2c_force_close(struct i2c_adapter *adap)
166 {
167 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
168 	struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
169 
170 	dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");
171 
172 	cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);
173 
174 	out_8(&i2c_reg->i2cmr, 0x00);	/* Disable all interrupts */
175 	out_8(&i2c_reg->i2cer, 0xff);
176 }
177 
178 static void cpm_i2c_parse_message(struct i2c_adapter *adap,
179 	struct i2c_msg *pmsg, int num, int tx, int rx)
180 {
181 	cbd_t __iomem *tbdf;
182 	cbd_t __iomem *rbdf;
183 	u_char addr;
184 	u_char *tb;
185 	u_char *rb;
186 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
187 
188 	tbdf = cpm->tbase + tx;
189 	rbdf = cpm->rbase + rx;
190 
191 	addr = i2c_8bit_addr_from_msg(pmsg);
192 
193 	tb = cpm->txbuf[tx];
194 	rb = cpm->rxbuf[rx];
195 
196 	/* Align read buffer */
197 	rb = (u_char *) (((ulong) rb + 1) & ~1);
198 
199 	tb[0] = addr;		/* Device address byte w/rw flag */
200 
201 	out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
202 	out_be16(&tbdf->cbd_sc, 0);
203 
204 	if (!(pmsg->flags & I2C_M_NOSTART))
205 		setbits16(&tbdf->cbd_sc, BD_I2C_START);
206 
207 	if (tx + 1 == num)
208 		setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);
209 
210 	if (pmsg->flags & I2C_M_RD) {
211 		/*
212 		 * To read, we need an empty buffer of the proper length.
213 		 * All that is used is the first byte for address, the remainder
214 		 * is just used for timing (and doesn't really have to exist).
215 		 */
216 
217 		dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);
218 
219 		out_be16(&rbdf->cbd_datlen, 0);
220 		out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
221 
222 		if (rx + 1 == CPM_MAXBD)
223 			setbits16(&rbdf->cbd_sc, BD_SC_WRAP);
224 
225 		eieio();
226 		setbits16(&tbdf->cbd_sc, BD_SC_READY);
227 	} else {
228 		dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr);
229 
230 		memcpy(tb+1, pmsg->buf, pmsg->len);
231 
232 		eieio();
233 		setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
234 	}
235 }
236 
237 static int cpm_i2c_check_message(struct i2c_adapter *adap,
238 	struct i2c_msg *pmsg, int tx, int rx)
239 {
240 	cbd_t __iomem *tbdf;
241 	cbd_t __iomem *rbdf;
242 	u_char *tb;
243 	u_char *rb;
244 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
245 
246 	tbdf = cpm->tbase + tx;
247 	rbdf = cpm->rbase + rx;
248 
249 	tb = cpm->txbuf[tx];
250 	rb = cpm->rxbuf[rx];
251 
252 	/* Align read buffer */
253 	rb = (u_char *) (((uint) rb + 1) & ~1);
254 
255 	eieio();
256 	if (pmsg->flags & I2C_M_RD) {
257 		dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
258 			in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));
259 
260 		if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
261 			dev_dbg(&adap->dev, "I2C read; No ack\n");
262 			return -ENXIO;
263 		}
264 		if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
265 			dev_err(&adap->dev,
266 				"I2C read; complete but rbuf empty\n");
267 			return -EREMOTEIO;
268 		}
269 		if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
270 			dev_err(&adap->dev, "I2C read; Overrun\n");
271 			return -EREMOTEIO;
272 		}
273 		memcpy(pmsg->buf, rb, pmsg->len);
274 	} else {
275 		dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
276 			in_be16(&tbdf->cbd_sc));
277 
278 		if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
279 			dev_dbg(&adap->dev, "I2C write; No ack\n");
280 			return -ENXIO;
281 		}
282 		if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
283 			dev_err(&adap->dev, "I2C write; Underrun\n");
284 			return -EIO;
285 		}
286 		if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
287 			dev_err(&adap->dev, "I2C write; Collision\n");
288 			return -EIO;
289 		}
290 	}
291 	return 0;
292 }
293 
294 static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
295 {
296 	struct cpm_i2c *cpm = i2c_get_adapdata(adap);
297 	struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
298 	struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
299 	struct i2c_msg *pmsg;
300 	int ret;
301 	int tptr;
302 	int rptr;
303 	cbd_t __iomem *tbdf;
304 	cbd_t __iomem *rbdf;
305 
306 	/* Reset to use first buffer */
307 	out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
308 	out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
309 
310 	tbdf = cpm->tbase;
311 	rbdf = cpm->rbase;
312 
313 	tptr = 0;
314 	rptr = 0;
315 
316 	/*
317 	 * If there was a collision in the last i2c transaction,
318 	 * Set I2COM_MASTER as it was cleared during collision.
319 	 */
320 	if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
321 		out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);
322 	}
323 
324 	while (tptr < num) {
325 		pmsg = &msgs[tptr];
326 		dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
327 
328 		cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
329 		if (pmsg->flags & I2C_M_RD)
330 			rptr++;
331 		tptr++;
332 	}
333 	/* Start transfer now */
334 	/* Enable RX/TX/Error interupts */
335 	out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB);
336 	out_8(&i2c_reg->i2cer, 0xff);	/* Clear interrupt status */
337 	/* Chip bug, set enable here */
338 	setbits8(&i2c_reg->i2mod, I2MOD_EN);	/* Enable */
339 	/* Begin transmission */
340 	setbits8(&i2c_reg->i2com, I2COM_START);
341 
342 	tptr = 0;
343 	rptr = 0;
344 
345 	while (tptr < num) {
346 		/* Check for outstanding messages */
347 		dev_dbg(&adap->dev, "test ready.\n");
348 		pmsg = &msgs[tptr];
349 		if (pmsg->flags & I2C_M_RD)
350 			ret = wait_event_timeout(cpm->i2c_wait,
351 				(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||
352 				!(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
353 				1 * HZ);
354 		else
355 			ret = wait_event_timeout(cpm->i2c_wait,
356 				!(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
357 				1 * HZ);
358 		if (ret == 0) {
359 			ret = -EREMOTEIO;
360 			dev_err(&adap->dev, "I2C transfer: timeout\n");
361 			goto out_err;
362 		}
363 		if (ret > 0) {
364 			dev_dbg(&adap->dev, "ready.\n");
365 			ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
366 			tptr++;
367 			if (pmsg->flags & I2C_M_RD)
368 				rptr++;
369 			if (ret)
370 				goto out_err;
371 		}
372 	}
373 #ifdef I2C_CHIP_ERRATA
374 	/*
375 	 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
376 	 * Disabling I2C too early may cause too short stop condition
377 	 */
378 	udelay(4);
379 	clrbits8(&i2c_reg->i2mod, I2MOD_EN);
380 #endif
381 	return (num);
382 
383 out_err:
384 	cpm_i2c_force_close(adap);
385 #ifdef I2C_CHIP_ERRATA
386 	/*
387 	 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
388 	 */
389 	clrbits8(&i2c_reg->i2mod, I2MOD_EN);
390 #endif
391 	return ret;
392 }
393 
394 static u32 cpm_i2c_func(struct i2c_adapter *adap)
395 {
396 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
397 }
398 
399 /* -----exported algorithm data: -------------------------------------	*/
400 
401 static const struct i2c_algorithm cpm_i2c_algo = {
402 	.master_xfer = cpm_i2c_xfer,
403 	.functionality = cpm_i2c_func,
404 };
405 
406 /* CPM_MAX_READ is also limiting writes according to the code! */
407 static const struct i2c_adapter_quirks cpm_i2c_quirks = {
408 	.max_num_msgs = CPM_MAXBD,
409 	.max_read_len = CPM_MAX_READ,
410 	.max_write_len = CPM_MAX_READ,
411 };
412 
413 static const struct i2c_adapter cpm_ops = {
414 	.owner		= THIS_MODULE,
415 	.name		= "i2c-cpm",
416 	.algo		= &cpm_i2c_algo,
417 	.quirks		= &cpm_i2c_quirks,
418 };
419 
420 static int cpm_i2c_setup(struct cpm_i2c *cpm)
421 {
422 	struct platform_device *ofdev = cpm->ofdev;
423 	const u32 *data;
424 	int len, ret, i;
425 	void __iomem *i2c_base;
426 	cbd_t __iomem *tbdf;
427 	cbd_t __iomem *rbdf;
428 	unsigned char brg;
429 
430 	dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");
431 
432 	init_waitqueue_head(&cpm->i2c_wait);
433 
434 	cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
435 	if (!cpm->irq)
436 		return -EINVAL;
437 
438 	/* Install interrupt handler. */
439 	ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
440 			  &cpm->adap);
441 	if (ret)
442 		return ret;
443 
444 	/* I2C parameter RAM */
445 	i2c_base = of_iomap(ofdev->dev.of_node, 1);
446 	if (i2c_base == NULL) {
447 		ret = -EINVAL;
448 		goto out_irq;
449 	}
450 
451 	if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) {
452 
453 		/* Check for and use a microcode relocation patch. */
454 		cpm->i2c_ram = i2c_base;
455 		cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);
456 
457 		/*
458 		 * Maybe should use cpm_muram_alloc instead of hardcoding
459 		 * this in micropatch.c
460 		 */
461 		if (cpm->i2c_addr) {
462 			cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
463 			iounmap(i2c_base);
464 		}
465 
466 		cpm->version = 1;
467 
468 	} else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) {
469 		cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
470 		cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
471 		out_be16(i2c_base, cpm->i2c_addr);
472 		iounmap(i2c_base);
473 
474 		cpm->version = 2;
475 
476 	} else {
477 		iounmap(i2c_base);
478 		ret = -EINVAL;
479 		goto out_irq;
480 	}
481 
482 	/* I2C control/status registers */
483 	cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0);
484 	if (cpm->i2c_reg == NULL) {
485 		ret = -EINVAL;
486 		goto out_ram;
487 	}
488 
489 	data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
490 	if (!data || len != 4) {
491 		ret = -EINVAL;
492 		goto out_reg;
493 	}
494 	cpm->cp_command = *data;
495 
496 	data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len);
497 	if (data && len == 4)
498 		cpm->adap.class = *data;
499 
500 	data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len);
501 	if (data && len == 4)
502 		cpm->freq = *data;
503 	else
504 		cpm->freq = 60000; /* use 60kHz i2c clock by default */
505 
506 	/*
507 	 * Allocate space for CPM_MAXBD transmit and receive buffer
508 	 * descriptors in the DP ram.
509 	 */
510 	cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
511 	if (!cpm->dp_addr) {
512 		ret = -ENOMEM;
513 		goto out_reg;
514 	}
515 
516 	cpm->tbase = cpm_muram_addr(cpm->dp_addr);
517 	cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);
518 
519 	/* Allocate TX and RX buffers */
520 
521 	tbdf = cpm->tbase;
522 	rbdf = cpm->rbase;
523 
524 	for (i = 0; i < CPM_MAXBD; i++) {
525 		cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
526 						   CPM_MAX_READ + 1,
527 						   &cpm->rxdma[i], GFP_KERNEL);
528 		if (!cpm->rxbuf[i]) {
529 			ret = -ENOMEM;
530 			goto out_muram;
531 		}
532 		out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));
533 
534 		cpm->txbuf[i] = (unsigned char *)dma_alloc_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, &cpm->txdma[i], GFP_KERNEL);
535 		if (!cpm->txbuf[i]) {
536 			ret = -ENOMEM;
537 			goto out_muram;
538 		}
539 		out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
540 	}
541 
542 	/* Initialize Tx/Rx parameters. */
543 
544 	cpm_reset_i2c_params(cpm);
545 
546 	dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
547 		cpm->i2c_ram, cpm->i2c_addr, cpm->freq);
548 	dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
549 		(u8 __iomem *)cpm->tbase - DPRAM_BASE,
550 		(u8 __iomem *)cpm->rbase - DPRAM_BASE);
551 
552 	cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);
553 
554 	/*
555 	 * Select an invalid address. Just make sure we don't use loopback mode
556 	 */
557 	out_8(&cpm->i2c_reg->i2add, 0x7f << 1);
558 
559 	/*
560 	 * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
561 	 * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
562 	 * the actual i2c bus frequency.
563 	 */
564 	brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
565 	out_8(&cpm->i2c_reg->i2brg, brg);
566 
567 	out_8(&cpm->i2c_reg->i2mod, 0x00);
568 	out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);	/* Master mode */
569 
570 	/* Disable interrupts. */
571 	out_8(&cpm->i2c_reg->i2cmr, 0);
572 	out_8(&cpm->i2c_reg->i2cer, 0xff);
573 
574 	return 0;
575 
576 out_muram:
577 	for (i = 0; i < CPM_MAXBD; i++) {
578 		if (cpm->rxbuf[i])
579 			dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
580 				cpm->rxbuf[i], cpm->rxdma[i]);
581 		if (cpm->txbuf[i])
582 			dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
583 				cpm->txbuf[i], cpm->txdma[i]);
584 	}
585 	cpm_muram_free(cpm->dp_addr);
586 out_reg:
587 	iounmap(cpm->i2c_reg);
588 out_ram:
589 	if ((cpm->version == 1) && (!cpm->i2c_addr))
590 		iounmap(cpm->i2c_ram);
591 	if (cpm->version == 2)
592 		cpm_muram_free(cpm->i2c_addr);
593 out_irq:
594 	free_irq(cpm->irq, &cpm->adap);
595 	return ret;
596 }
597 
598 static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
599 {
600 	int i;
601 
602 	/* Shut down I2C. */
603 	clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);
604 
605 	/* Disable interrupts */
606 	out_8(&cpm->i2c_reg->i2cmr, 0);
607 	out_8(&cpm->i2c_reg->i2cer, 0xff);
608 
609 	free_irq(cpm->irq, &cpm->adap);
610 
611 	/* Free all memory */
612 	for (i = 0; i < CPM_MAXBD; i++) {
613 		dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
614 			cpm->rxbuf[i], cpm->rxdma[i]);
615 		dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
616 			cpm->txbuf[i], cpm->txdma[i]);
617 	}
618 
619 	cpm_muram_free(cpm->dp_addr);
620 	iounmap(cpm->i2c_reg);
621 
622 	if ((cpm->version == 1) && (!cpm->i2c_addr))
623 		iounmap(cpm->i2c_ram);
624 	if (cpm->version == 2)
625 		cpm_muram_free(cpm->i2c_addr);
626 }
627 
628 static int cpm_i2c_probe(struct platform_device *ofdev)
629 {
630 	int result, len;
631 	struct cpm_i2c *cpm;
632 	const u32 *data;
633 
634 	cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
635 	if (!cpm)
636 		return -ENOMEM;
637 
638 	cpm->ofdev = ofdev;
639 
640 	platform_set_drvdata(ofdev, cpm);
641 
642 	cpm->adap = cpm_ops;
643 	i2c_set_adapdata(&cpm->adap, cpm);
644 	cpm->adap.dev.parent = &ofdev->dev;
645 	cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node);
646 
647 	result = cpm_i2c_setup(cpm);
648 	if (result) {
649 		dev_err(&ofdev->dev, "Unable to init hardware\n");
650 		goto out_free;
651 	}
652 
653 	/* register new adapter to i2c module... */
654 
655 	data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
656 	cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1;
657 	result = i2c_add_numbered_adapter(&cpm->adap);
658 
659 	if (result < 0)
660 		goto out_shut;
661 
662 	dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
663 		cpm->adap.name);
664 
665 	return 0;
666 out_shut:
667 	cpm_i2c_shutdown(cpm);
668 out_free:
669 	kfree(cpm);
670 
671 	return result;
672 }
673 
674 static int cpm_i2c_remove(struct platform_device *ofdev)
675 {
676 	struct cpm_i2c *cpm = platform_get_drvdata(ofdev);
677 
678 	i2c_del_adapter(&cpm->adap);
679 
680 	cpm_i2c_shutdown(cpm);
681 
682 	kfree(cpm);
683 
684 	return 0;
685 }
686 
687 static const struct of_device_id cpm_i2c_match[] = {
688 	{
689 		.compatible = "fsl,cpm1-i2c",
690 	},
691 	{
692 		.compatible = "fsl,cpm2-i2c",
693 	},
694 	{},
695 };
696 
697 MODULE_DEVICE_TABLE(of, cpm_i2c_match);
698 
699 static struct platform_driver cpm_i2c_driver = {
700 	.probe		= cpm_i2c_probe,
701 	.remove		= cpm_i2c_remove,
702 	.driver = {
703 		.name = "fsl-i2c-cpm",
704 		.of_match_table = cpm_i2c_match,
705 	},
706 };
707 
708 module_platform_driver(cpm_i2c_driver);
709 
710 MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
711 MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
712 MODULE_LICENSE("GPL");
713