xref: /linux/drivers/i2c/busses/i2c-mpc.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  * (C) Copyright 2003-2004
3  * Humboldt Solutions Ltd, adrian@humboldt.co.uk.
4 
5  * This is a combined i2c adapter and algorithm driver for the
6  * MPC107/Tsi107 PowerPC northbridge and processors that include
7  * the same I2C unit (8240, 8245, 85xx).
8  *
9  * Release 0.8
10  *
11  * This file is licensed under the terms of the GNU General Public
12  * License version 2. This program is licensed "as is" without any
13  * warranty of any kind, whether express or implied.
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/init.h>
20 #include <linux/of_platform.h>
21 #include <linux/of_i2c.h>
22 #include <linux/slab.h>
23 
24 #include <linux/io.h>
25 #include <linux/fsl_devices.h>
26 #include <linux/i2c.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
29 
30 #include <asm/mpc52xx.h>
31 #include <sysdev/fsl_soc.h>
32 
33 #define DRV_NAME "mpc-i2c"
34 
35 #define MPC_I2C_CLOCK_LEGACY   0
36 #define MPC_I2C_CLOCK_PRESERVE (~0U)
37 
38 #define MPC_I2C_FDR   0x04
39 #define MPC_I2C_CR    0x08
40 #define MPC_I2C_SR    0x0c
41 #define MPC_I2C_DR    0x10
42 #define MPC_I2C_DFSRR 0x14
43 
44 #define CCR_MEN  0x80
45 #define CCR_MIEN 0x40
46 #define CCR_MSTA 0x20
47 #define CCR_MTX  0x10
48 #define CCR_TXAK 0x08
49 #define CCR_RSTA 0x04
50 
51 #define CSR_MCF  0x80
52 #define CSR_MAAS 0x40
53 #define CSR_MBB  0x20
54 #define CSR_MAL  0x10
55 #define CSR_SRW  0x04
56 #define CSR_MIF  0x02
57 #define CSR_RXAK 0x01
58 
59 struct mpc_i2c {
60 	struct device *dev;
61 	void __iomem *base;
62 	u32 interrupt;
63 	wait_queue_head_t queue;
64 	struct i2c_adapter adap;
65 	int irq;
66 	u32 real_clk;
67 };
68 
69 struct mpc_i2c_divider {
70 	u16 divider;
71 	u16 fdr;	/* including dfsrr */
72 };
73 
74 struct mpc_i2c_data {
75 	void (*setup)(struct device_node *node, struct mpc_i2c *i2c,
76 		      u32 clock, u32 prescaler);
77 	u32 prescaler;
78 };
79 
80 static inline void writeccr(struct mpc_i2c *i2c, u32 x)
81 {
82 	writeb(x, i2c->base + MPC_I2C_CR);
83 }
84 
85 static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
86 {
87 	struct mpc_i2c *i2c = dev_id;
88 	if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) {
89 		/* Read again to allow register to stabilise */
90 		i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
91 		writeb(0, i2c->base + MPC_I2C_SR);
92 		wake_up(&i2c->queue);
93 	}
94 	return IRQ_HANDLED;
95 }
96 
97 /* Sometimes 9th clock pulse isn't generated, and slave doesn't release
98  * the bus, because it wants to send ACK.
99  * Following sequence of enabling/disabling and sending start/stop generates
100  * the 9 pulses, so it's all OK.
101  */
102 static void mpc_i2c_fixup(struct mpc_i2c *i2c)
103 {
104 	int k;
105 	u32 delay_val = 1000000 / i2c->real_clk + 1;
106 
107 	if (delay_val < 2)
108 		delay_val = 2;
109 
110 	for (k = 9; k; k--) {
111 		writeccr(i2c, 0);
112 		writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN);
113 		udelay(delay_val);
114 		writeccr(i2c, CCR_MEN);
115 		udelay(delay_val << 1);
116 	}
117 }
118 
119 static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
120 {
121 	unsigned long orig_jiffies = jiffies;
122 	u32 x;
123 	int result = 0;
124 
125 	if (!i2c->irq) {
126 		while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) {
127 			schedule();
128 			if (time_after(jiffies, orig_jiffies + timeout)) {
129 				dev_dbg(i2c->dev, "timeout\n");
130 				writeccr(i2c, 0);
131 				result = -EIO;
132 				break;
133 			}
134 		}
135 		x = readb(i2c->base + MPC_I2C_SR);
136 		writeb(0, i2c->base + MPC_I2C_SR);
137 	} else {
138 		/* Interrupt mode */
139 		result = wait_event_timeout(i2c->queue,
140 			(i2c->interrupt & CSR_MIF), timeout);
141 
142 		if (unlikely(!(i2c->interrupt & CSR_MIF))) {
143 			dev_dbg(i2c->dev, "wait timeout\n");
144 			writeccr(i2c, 0);
145 			result = -ETIMEDOUT;
146 		}
147 
148 		x = i2c->interrupt;
149 		i2c->interrupt = 0;
150 	}
151 
152 	if (result < 0)
153 		return result;
154 
155 	if (!(x & CSR_MCF)) {
156 		dev_dbg(i2c->dev, "unfinished\n");
157 		return -EIO;
158 	}
159 
160 	if (x & CSR_MAL) {
161 		dev_dbg(i2c->dev, "MAL\n");
162 		return -EIO;
163 	}
164 
165 	if (writing && (x & CSR_RXAK)) {
166 		dev_dbg(i2c->dev, "No RXAK\n");
167 		/* generate stop */
168 		writeccr(i2c, CCR_MEN);
169 		return -EIO;
170 	}
171 	return 0;
172 }
173 
174 #if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
175 static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] __devinitconst = {
176 	{20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
177 	{28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
178 	{36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
179 	{52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a},
180 	{68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09},
181 	{96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81},
182 	{128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30},
183 	{176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32},
184 	{240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10},
185 	{320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a},
186 	{448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14},
187 	{640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17},
188 	{1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d},
189 	{1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c},
190 	{2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f},
191 	{4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e},
192 	{7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c},
193 	{10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
194 };
195 
196 static int __devinit mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
197 					  int prescaler, u32 *real_clk)
198 {
199 	const struct mpc_i2c_divider *div = NULL;
200 	unsigned int pvr = mfspr(SPRN_PVR);
201 	u32 divider;
202 	int i;
203 
204 	if (clock == MPC_I2C_CLOCK_LEGACY) {
205 		/* see below - default fdr = 0x3f -> div = 2048 */
206 		*real_clk = mpc5xxx_get_bus_frequency(node) / 2048;
207 		return -EINVAL;
208 	}
209 
210 	/* Determine divider value */
211 	divider = mpc5xxx_get_bus_frequency(node) / clock;
212 
213 	/*
214 	 * We want to choose an FDR/DFSR that generates an I2C bus speed that
215 	 * is equal to or lower than the requested speed.
216 	 */
217 	for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_52xx); i++) {
218 		div = &mpc_i2c_dividers_52xx[i];
219 		/* Old MPC5200 rev A CPUs do not support the high bits */
220 		if (div->fdr & 0xc0 && pvr == 0x80822011)
221 			continue;
222 		if (div->divider >= divider)
223 			break;
224 	}
225 
226 	*real_clk = mpc5xxx_get_bus_frequency(node) / div->divider;
227 	return (int)div->fdr;
228 }
229 
230 static void __devinit mpc_i2c_setup_52xx(struct device_node *node,
231 					 struct mpc_i2c *i2c,
232 					 u32 clock, u32 prescaler)
233 {
234 	int ret, fdr;
235 
236 	if (clock == MPC_I2C_CLOCK_PRESERVE) {
237 		dev_dbg(i2c->dev, "using fdr %d\n",
238 			readb(i2c->base + MPC_I2C_FDR));
239 		return;
240 	}
241 
242 	ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler, &i2c->real_clk);
243 	fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
244 
245 	writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
246 
247 	if (ret >= 0)
248 		dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk,
249 			 fdr);
250 }
251 #else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
252 static void __devinit mpc_i2c_setup_52xx(struct device_node *node,
253 					 struct mpc_i2c *i2c,
254 					 u32 clock, u32 prescaler)
255 {
256 }
257 #endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
258 
259 #ifdef CONFIG_PPC_MPC512x
260 static void __devinit mpc_i2c_setup_512x(struct device_node *node,
261 					 struct mpc_i2c *i2c,
262 					 u32 clock, u32 prescaler)
263 {
264 	struct device_node *node_ctrl;
265 	void __iomem *ctrl;
266 	const u32 *pval;
267 	u32 idx;
268 
269 	/* Enable I2C interrupts for mpc5121 */
270 	node_ctrl = of_find_compatible_node(NULL, NULL,
271 					    "fsl,mpc5121-i2c-ctrl");
272 	if (node_ctrl) {
273 		ctrl = of_iomap(node_ctrl, 0);
274 		if (ctrl) {
275 			/* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
276 			pval = of_get_property(node, "reg", NULL);
277 			idx = (*pval & 0xff) / 0x20;
278 			setbits32(ctrl, 1 << (24 + idx * 2));
279 			iounmap(ctrl);
280 		}
281 		of_node_put(node_ctrl);
282 	}
283 
284 	/* The clock setup for the 52xx works also fine for the 512x */
285 	mpc_i2c_setup_52xx(node, i2c, clock, prescaler);
286 }
287 #else /* CONFIG_PPC_MPC512x */
288 static void __devinit mpc_i2c_setup_512x(struct device_node *node,
289 					 struct mpc_i2c *i2c,
290 					 u32 clock, u32 prescaler)
291 {
292 }
293 #endif /* CONFIG_PPC_MPC512x */
294 
295 #ifdef CONFIG_FSL_SOC
296 static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] __devinitconst = {
297 	{160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
298 	{288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
299 	{416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
300 	{544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105},
301 	{672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106},
302 	{800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107},
303 	{1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07},
304 	{1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a},
305 	{1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b},
306 	{2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e},
307 	{3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133},
308 	{4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136},
309 	{7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115},
310 	{12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b},
311 	{18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e},
312 	{30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d},
313 	{49152, 0x011e}, {61440, 0x011f}
314 };
315 
316 static u32 __devinit mpc_i2c_get_sec_cfg_8xxx(void)
317 {
318 	struct device_node *node = NULL;
319 	u32 __iomem *reg;
320 	u32 val = 0;
321 
322 	node = of_find_node_by_name(NULL, "global-utilities");
323 	if (node) {
324 		const u32 *prop = of_get_property(node, "reg", NULL);
325 		if (prop) {
326 			/*
327 			 * Map and check POR Device Status Register 2
328 			 * (PORDEVSR2) at 0xE0014
329 			 */
330 			reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
331 			if (!reg)
332 				printk(KERN_ERR
333 				       "Error: couldn't map PORDEVSR2\n");
334 			else
335 				val = in_be32(reg) & 0x00000080; /* sec-cfg */
336 			iounmap(reg);
337 		}
338 	}
339 	if (node)
340 		of_node_put(node);
341 
342 	return val;
343 }
344 
345 static int __devinit mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
346 					  u32 prescaler, u32 *real_clk)
347 {
348 	const struct mpc_i2c_divider *div = NULL;
349 	u32 divider;
350 	int i;
351 
352 	if (clock == MPC_I2C_CLOCK_LEGACY) {
353 		/* see below - default fdr = 0x1031 -> div = 16 * 3072 */
354 		*real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
355 		return -EINVAL;
356 	}
357 
358 	/* Determine proper divider value */
359 	if (of_device_is_compatible(node, "fsl,mpc8544-i2c"))
360 		prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
361 	if (!prescaler)
362 		prescaler = 1;
363 
364 	divider = fsl_get_sys_freq() / clock / prescaler;
365 
366 	pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
367 		 fsl_get_sys_freq(), clock, divider);
368 
369 	/*
370 	 * We want to choose an FDR/DFSR that generates an I2C bus speed that
371 	 * is equal to or lower than the requested speed.
372 	 */
373 	for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
374 		div = &mpc_i2c_dividers_8xxx[i];
375 		if (div->divider >= divider)
376 			break;
377 	}
378 
379 	*real_clk = fsl_get_sys_freq() / prescaler / div->divider;
380 	return div ? (int)div->fdr : -EINVAL;
381 }
382 
383 static void __devinit mpc_i2c_setup_8xxx(struct device_node *node,
384 					 struct mpc_i2c *i2c,
385 					 u32 clock, u32 prescaler)
386 {
387 	int ret, fdr;
388 
389 	if (clock == MPC_I2C_CLOCK_PRESERVE) {
390 		dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
391 			readb(i2c->base + MPC_I2C_DFSRR),
392 			readb(i2c->base + MPC_I2C_FDR));
393 		return;
394 	}
395 
396 	ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler, &i2c->real_clk);
397 	fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
398 
399 	writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
400 	writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
401 
402 	if (ret >= 0)
403 		dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
404 			 i2c->real_clk, fdr >> 8, fdr & 0xff);
405 }
406 
407 #else /* !CONFIG_FSL_SOC */
408 static void __devinit mpc_i2c_setup_8xxx(struct device_node *node,
409 					 struct mpc_i2c *i2c,
410 					 u32 clock, u32 prescaler)
411 {
412 }
413 #endif /* CONFIG_FSL_SOC */
414 
415 static void mpc_i2c_start(struct mpc_i2c *i2c)
416 {
417 	/* Clear arbitration */
418 	writeb(0, i2c->base + MPC_I2C_SR);
419 	/* Start with MEN */
420 	writeccr(i2c, CCR_MEN);
421 }
422 
423 static void mpc_i2c_stop(struct mpc_i2c *i2c)
424 {
425 	writeccr(i2c, CCR_MEN);
426 }
427 
428 static int mpc_write(struct mpc_i2c *i2c, int target,
429 		     const u8 *data, int length, int restart)
430 {
431 	int i, result;
432 	unsigned timeout = i2c->adap.timeout;
433 	u32 flags = restart ? CCR_RSTA : 0;
434 
435 	/* Start as master */
436 	writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
437 	/* Write target byte */
438 	writeb((target << 1), i2c->base + MPC_I2C_DR);
439 
440 	result = i2c_wait(i2c, timeout, 1);
441 	if (result < 0)
442 		return result;
443 
444 	for (i = 0; i < length; i++) {
445 		/* Write data byte */
446 		writeb(data[i], i2c->base + MPC_I2C_DR);
447 
448 		result = i2c_wait(i2c, timeout, 1);
449 		if (result < 0)
450 			return result;
451 	}
452 
453 	return 0;
454 }
455 
456 static int mpc_read(struct mpc_i2c *i2c, int target,
457 		    u8 *data, int length, int restart)
458 {
459 	unsigned timeout = i2c->adap.timeout;
460 	int i, result;
461 	u32 flags = restart ? CCR_RSTA : 0;
462 
463 	/* Switch to read - restart */
464 	writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
465 	/* Write target address byte - this time with the read flag set */
466 	writeb((target << 1) | 1, i2c->base + MPC_I2C_DR);
467 
468 	result = i2c_wait(i2c, timeout, 1);
469 	if (result < 0)
470 		return result;
471 
472 	if (length) {
473 		if (length == 1)
474 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
475 		else
476 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
477 		/* Dummy read */
478 		readb(i2c->base + MPC_I2C_DR);
479 	}
480 
481 	for (i = 0; i < length; i++) {
482 		result = i2c_wait(i2c, timeout, 0);
483 		if (result < 0)
484 			return result;
485 
486 		/* Generate txack on next to last byte */
487 		if (i == length - 2)
488 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
489 		/* Do not generate stop on last byte */
490 		if (i == length - 1)
491 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX);
492 		data[i] = readb(i2c->base + MPC_I2C_DR);
493 	}
494 
495 	return length;
496 }
497 
498 static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
499 {
500 	struct i2c_msg *pmsg;
501 	int i;
502 	int ret = 0;
503 	unsigned long orig_jiffies = jiffies;
504 	struct mpc_i2c *i2c = i2c_get_adapdata(adap);
505 
506 	mpc_i2c_start(i2c);
507 
508 	/* Allow bus up to 1s to become not busy */
509 	while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
510 		if (signal_pending(current)) {
511 			dev_dbg(i2c->dev, "Interrupted\n");
512 			writeccr(i2c, 0);
513 			return -EINTR;
514 		}
515 		if (time_after(jiffies, orig_jiffies + HZ)) {
516 			u8 status = readb(i2c->base + MPC_I2C_SR);
517 
518 			dev_dbg(i2c->dev, "timeout\n");
519 			if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
520 				writeb(status & ~CSR_MAL,
521 				       i2c->base + MPC_I2C_SR);
522 				mpc_i2c_fixup(i2c);
523 			}
524 			return -EIO;
525 		}
526 		schedule();
527 	}
528 
529 	for (i = 0; ret >= 0 && i < num; i++) {
530 		pmsg = &msgs[i];
531 		dev_dbg(i2c->dev,
532 			"Doing %s %d bytes to 0x%02x - %d of %d messages\n",
533 			pmsg->flags & I2C_M_RD ? "read" : "write",
534 			pmsg->len, pmsg->addr, i + 1, num);
535 		if (pmsg->flags & I2C_M_RD)
536 			ret =
537 			    mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
538 		else
539 			ret =
540 			    mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
541 	}
542 	mpc_i2c_stop(i2c);
543 	return (ret < 0) ? ret : num;
544 }
545 
546 static u32 mpc_functionality(struct i2c_adapter *adap)
547 {
548 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
549 }
550 
551 static const struct i2c_algorithm mpc_algo = {
552 	.master_xfer = mpc_xfer,
553 	.functionality = mpc_functionality,
554 };
555 
556 static struct i2c_adapter mpc_ops = {
557 	.owner = THIS_MODULE,
558 	.name = "MPC adapter",
559 	.algo = &mpc_algo,
560 	.timeout = HZ,
561 };
562 
563 static const struct of_device_id mpc_i2c_of_match[];
564 static int __devinit fsl_i2c_probe(struct platform_device *op)
565 {
566 	const struct of_device_id *match;
567 	struct mpc_i2c *i2c;
568 	const u32 *prop;
569 	u32 clock = MPC_I2C_CLOCK_LEGACY;
570 	int result = 0;
571 	int plen;
572 
573 	match = of_match_device(mpc_i2c_of_match, &op->dev);
574 	if (!match)
575 		return -EINVAL;
576 
577 	i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
578 	if (!i2c)
579 		return -ENOMEM;
580 
581 	i2c->dev = &op->dev; /* for debug and error output */
582 
583 	init_waitqueue_head(&i2c->queue);
584 
585 	i2c->base = of_iomap(op->dev.of_node, 0);
586 	if (!i2c->base) {
587 		dev_err(i2c->dev, "failed to map controller\n");
588 		result = -ENOMEM;
589 		goto fail_map;
590 	}
591 
592 	i2c->irq = irq_of_parse_and_map(op->dev.of_node, 0);
593 	if (i2c->irq) { /* no i2c->irq implies polling */
594 		result = request_irq(i2c->irq, mpc_i2c_isr,
595 				     IRQF_SHARED, "i2c-mpc", i2c);
596 		if (result < 0) {
597 			dev_err(i2c->dev, "failed to attach interrupt\n");
598 			goto fail_request;
599 		}
600 	}
601 
602 	if (of_get_property(op->dev.of_node, "fsl,preserve-clocking", NULL)) {
603 		clock = MPC_I2C_CLOCK_PRESERVE;
604 	} else {
605 		prop = of_get_property(op->dev.of_node, "clock-frequency",
606 					&plen);
607 		if (prop && plen == sizeof(u32))
608 			clock = *prop;
609 	}
610 
611 	if (match->data) {
612 		struct mpc_i2c_data *data = match->data;
613 		data->setup(op->dev.of_node, i2c, clock, data->prescaler);
614 	} else {
615 		/* Backwards compatibility */
616 		if (of_get_property(op->dev.of_node, "dfsrr", NULL))
617 			mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock, 0);
618 	}
619 
620 	prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen);
621 	if (prop && plen == sizeof(u32)) {
622 		mpc_ops.timeout = *prop * HZ / 1000000;
623 		if (mpc_ops.timeout < 5)
624 			mpc_ops.timeout = 5;
625 	}
626 	dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
627 
628 	dev_set_drvdata(&op->dev, i2c);
629 
630 	i2c->adap = mpc_ops;
631 	i2c_set_adapdata(&i2c->adap, i2c);
632 	i2c->adap.dev.parent = &op->dev;
633 	i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
634 
635 	result = i2c_add_adapter(&i2c->adap);
636 	if (result < 0) {
637 		dev_err(i2c->dev, "failed to add adapter\n");
638 		goto fail_add;
639 	}
640 	of_i2c_register_devices(&i2c->adap);
641 
642 	return result;
643 
644  fail_add:
645 	dev_set_drvdata(&op->dev, NULL);
646 	free_irq(i2c->irq, i2c);
647  fail_request:
648 	irq_dispose_mapping(i2c->irq);
649 	iounmap(i2c->base);
650  fail_map:
651 	kfree(i2c);
652 	return result;
653 };
654 
655 static int __devexit fsl_i2c_remove(struct platform_device *op)
656 {
657 	struct mpc_i2c *i2c = dev_get_drvdata(&op->dev);
658 
659 	i2c_del_adapter(&i2c->adap);
660 	dev_set_drvdata(&op->dev, NULL);
661 
662 	if (i2c->irq)
663 		free_irq(i2c->irq, i2c);
664 
665 	irq_dispose_mapping(i2c->irq);
666 	iounmap(i2c->base);
667 	kfree(i2c);
668 	return 0;
669 };
670 
671 static struct mpc_i2c_data mpc_i2c_data_512x __devinitdata = {
672 	.setup = mpc_i2c_setup_512x,
673 };
674 
675 static struct mpc_i2c_data mpc_i2c_data_52xx __devinitdata = {
676 	.setup = mpc_i2c_setup_52xx,
677 };
678 
679 static struct mpc_i2c_data mpc_i2c_data_8313 __devinitdata = {
680 	.setup = mpc_i2c_setup_8xxx,
681 };
682 
683 static struct mpc_i2c_data mpc_i2c_data_8543 __devinitdata = {
684 	.setup = mpc_i2c_setup_8xxx,
685 	.prescaler = 2,
686 };
687 
688 static struct mpc_i2c_data mpc_i2c_data_8544 __devinitdata = {
689 	.setup = mpc_i2c_setup_8xxx,
690 	.prescaler = 3,
691 };
692 
693 static const struct of_device_id mpc_i2c_of_match[] = {
694 	{.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
695 	{.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
696 	{.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
697 	{.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
698 	{.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
699 	{.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
700 	{.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
701 	/* Backward compatibility */
702 	{.compatible = "fsl-i2c", },
703 	{},
704 };
705 MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
706 
707 /* Structure for a device driver */
708 static struct platform_driver mpc_i2c_driver = {
709 	.probe		= fsl_i2c_probe,
710 	.remove		= __devexit_p(fsl_i2c_remove),
711 	.driver = {
712 		.owner = THIS_MODULE,
713 		.name = DRV_NAME,
714 		.of_match_table = mpc_i2c_of_match,
715 	},
716 };
717 
718 static int __init fsl_i2c_init(void)
719 {
720 	return platform_driver_register(&mpc_i2c_driver);
721 }
722 
723 static void __exit fsl_i2c_exit(void)
724 {
725 	platform_driver_unregister(&mpc_i2c_driver);
726 }
727 
728 module_init(fsl_i2c_init);
729 module_exit(fsl_i2c_exit);
730 
731 MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
732 MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
733 		   "MPC824x/83xx/85xx/86xx/512x/52xx processors");
734 MODULE_LICENSE("GPL");
735