xref: /openbmc/linux/drivers/i2c/busses/i2c-eg20t.c (revision 565d76cb)
1 /*
2  * Copyright (C) 2010 OKI SEMICONDUCTOR CO., LTD.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; version 2 of the License.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
16  */
17 
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/delay.h>
21 #include <linux/init.h>
22 #include <linux/errno.h>
23 #include <linux/i2c.h>
24 #include <linux/fs.h>
25 #include <linux/io.h>
26 #include <linux/types.h>
27 #include <linux/interrupt.h>
28 #include <linux/jiffies.h>
29 #include <linux/pci.h>
30 #include <linux/mutex.h>
31 #include <linux/ktime.h>
32 #include <linux/slab.h>
33 
34 #define PCH_EVENT_SET	0	/* I2C Interrupt Event Set Status */
35 #define PCH_EVENT_NONE	1	/* I2C Interrupt Event Clear Status */
36 #define PCH_MAX_CLK		100000	/* Maximum Clock speed in MHz */
37 #define PCH_BUFFER_MODE_ENABLE	0x0002	/* flag for Buffer mode enable */
38 #define PCH_EEPROM_SW_RST_MODE_ENABLE	0x0008	/* EEPROM SW RST enable flag */
39 
40 #define PCH_I2CSADR	0x00	/* I2C slave address register */
41 #define PCH_I2CCTL	0x04	/* I2C control register */
42 #define PCH_I2CSR	0x08	/* I2C status register */
43 #define PCH_I2CDR	0x0C	/* I2C data register */
44 #define PCH_I2CMON	0x10	/* I2C bus monitor register */
45 #define PCH_I2CBC	0x14	/* I2C bus transfer rate setup counter */
46 #define PCH_I2CMOD	0x18	/* I2C mode register */
47 #define PCH_I2CBUFSLV	0x1C	/* I2C buffer mode slave address register */
48 #define PCH_I2CBUFSUB	0x20	/* I2C buffer mode subaddress register */
49 #define PCH_I2CBUFFOR	0x24	/* I2C buffer mode format register */
50 #define PCH_I2CBUFCTL	0x28	/* I2C buffer mode control register */
51 #define PCH_I2CBUFMSK	0x2C	/* I2C buffer mode interrupt mask register */
52 #define PCH_I2CBUFSTA	0x30	/* I2C buffer mode status register */
53 #define PCH_I2CBUFLEV	0x34	/* I2C buffer mode level register */
54 #define PCH_I2CESRFOR	0x38	/* EEPROM software reset mode format register */
55 #define PCH_I2CESRCTL	0x3C	/* EEPROM software reset mode ctrl register */
56 #define PCH_I2CESRMSK	0x40	/* EEPROM software reset mode */
57 #define PCH_I2CESRSTA	0x44	/* EEPROM software reset mode status register */
58 #define PCH_I2CTMR	0x48	/* I2C timer register */
59 #define PCH_I2CSRST	0xFC	/* I2C reset register */
60 #define PCH_I2CNF	0xF8	/* I2C noise filter register */
61 
62 #define BUS_IDLE_TIMEOUT	20
63 #define PCH_I2CCTL_I2CMEN	0x0080
64 #define TEN_BIT_ADDR_DEFAULT	0xF000
65 #define TEN_BIT_ADDR_MASK	0xF0
66 #define PCH_START		0x0020
67 #define PCH_ESR_START		0x0001
68 #define PCH_BUFF_START		0x1
69 #define PCH_REPSTART		0x0004
70 #define PCH_ACK			0x0008
71 #define PCH_GETACK		0x0001
72 #define CLR_REG			0x0
73 #define I2C_RD			0x1
74 #define I2CMCF_BIT		0x0080
75 #define I2CMIF_BIT		0x0002
76 #define I2CMAL_BIT		0x0010
77 #define I2CBMFI_BIT		0x0001
78 #define I2CBMAL_BIT		0x0002
79 #define I2CBMNA_BIT		0x0004
80 #define I2CBMTO_BIT		0x0008
81 #define I2CBMIS_BIT		0x0010
82 #define I2CESRFI_BIT		0X0001
83 #define I2CESRTO_BIT		0x0002
84 #define I2CESRFIIE_BIT		0x1
85 #define I2CESRTOIE_BIT		0x2
86 #define I2CBMDZ_BIT		0x0040
87 #define I2CBMAG_BIT		0x0020
88 #define I2CMBB_BIT		0x0020
89 #define BUFFER_MODE_MASK	(I2CBMFI_BIT | I2CBMAL_BIT | I2CBMNA_BIT | \
90 				I2CBMTO_BIT | I2CBMIS_BIT)
91 #define I2C_ADDR_MSK		0xFF
92 #define I2C_MSB_2B_MSK		0x300
93 #define FAST_MODE_CLK		400
94 #define FAST_MODE_EN		0x0001
95 #define SUB_ADDR_LEN_MAX	4
96 #define BUF_LEN_MAX		32
97 #define PCH_BUFFER_MODE		0x1
98 #define EEPROM_SW_RST_MODE	0x0002
99 #define NORMAL_INTR_ENBL	0x0300
100 #define EEPROM_RST_INTR_ENBL	(I2CESRFIIE_BIT | I2CESRTOIE_BIT)
101 #define EEPROM_RST_INTR_DISBL	0x0
102 #define BUFFER_MODE_INTR_ENBL	0x001F
103 #define BUFFER_MODE_INTR_DISBL	0x0
104 #define NORMAL_MODE		0x0
105 #define BUFFER_MODE		0x1
106 #define EEPROM_SR_MODE		0x2
107 #define I2C_TX_MODE		0x0010
108 #define PCH_BUF_TX		0xFFF7
109 #define PCH_BUF_RD		0x0008
110 #define I2C_ERROR_MASK	(I2CESRTO_EVENT | I2CBMIS_EVENT | I2CBMTO_EVENT | \
111 			I2CBMNA_EVENT | I2CBMAL_EVENT | I2CMAL_EVENT)
112 #define I2CMAL_EVENT		0x0001
113 #define I2CMCF_EVENT		0x0002
114 #define I2CBMFI_EVENT		0x0004
115 #define I2CBMAL_EVENT		0x0008
116 #define I2CBMNA_EVENT		0x0010
117 #define I2CBMTO_EVENT		0x0020
118 #define I2CBMIS_EVENT		0x0040
119 #define I2CESRFI_EVENT		0x0080
120 #define I2CESRTO_EVENT		0x0100
121 #define PCI_DEVICE_ID_PCH_I2C	0x8817
122 
123 #define pch_dbg(adap, fmt, arg...)  \
124 	dev_dbg(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
125 
126 #define pch_err(adap, fmt, arg...)  \
127 	dev_err(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
128 
129 #define pch_pci_err(pdev, fmt, arg...)  \
130 	dev_err(&pdev->dev, "%s :" fmt, __func__, ##arg)
131 
132 #define pch_pci_dbg(pdev, fmt, arg...)  \
133 	dev_dbg(&pdev->dev, "%s :" fmt, __func__, ##arg)
134 
135 /*
136 Set the number of I2C instance max
137 Intel EG20T PCH :		1ch
138 OKI SEMICONDUCTOR ML7213 IOH :	2ch
139 */
140 #define PCH_I2C_MAX_DEV			2
141 
142 /**
143  * struct i2c_algo_pch_data - for I2C driver functionalities
144  * @pch_adapter:		stores the reference to i2c_adapter structure
145  * @p_adapter_info:		stores the reference to adapter_info structure
146  * @pch_base_address:		specifies the remapped base address
147  * @pch_buff_mode_en:		specifies if buffer mode is enabled
148  * @pch_event_flag:		specifies occurrence of interrupt events
149  * @pch_i2c_xfer_in_progress:	specifies whether the transfer is completed
150  */
151 struct i2c_algo_pch_data {
152 	struct i2c_adapter pch_adapter;
153 	struct adapter_info *p_adapter_info;
154 	void __iomem *pch_base_address;
155 	int pch_buff_mode_en;
156 	u32 pch_event_flag;
157 	bool pch_i2c_xfer_in_progress;
158 };
159 
160 /**
161  * struct adapter_info - This structure holds the adapter information for the
162 			 PCH i2c controller
163  * @pch_data:		stores a list of i2c_algo_pch_data
164  * @pch_i2c_suspended:	specifies whether the system is suspended or not
165  *			perhaps with more lines and words.
166  * @ch_num:		specifies the number of i2c instance
167  *
168  * pch_data has as many elements as maximum I2C channels
169  */
170 struct adapter_info {
171 	struct i2c_algo_pch_data pch_data[PCH_I2C_MAX_DEV];
172 	bool pch_i2c_suspended;
173 	int ch_num;
174 };
175 
176 
177 static int pch_i2c_speed = 100; /* I2C bus speed in Kbps */
178 static int pch_clk = 50000;	/* specifies I2C clock speed in KHz */
179 static wait_queue_head_t pch_event;
180 static DEFINE_MUTEX(pch_mutex);
181 
182 /* Definition for ML7213 by OKI SEMICONDUCTOR */
183 #define PCI_VENDOR_ID_ROHM		0x10DB
184 #define PCI_DEVICE_ID_ML7213_I2C	0x802D
185 
186 static struct pci_device_id __devinitdata pch_pcidev_id[] = {
187 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PCH_I2C),   1, },
188 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_I2C), 2, },
189 	{0,}
190 };
191 
192 static irqreturn_t pch_i2c_handler(int irq, void *pData);
193 
194 static inline void pch_setbit(void __iomem *addr, u32 offset, u32 bitmask)
195 {
196 	u32 val;
197 	val = ioread32(addr + offset);
198 	val |= bitmask;
199 	iowrite32(val, addr + offset);
200 }
201 
202 static inline void pch_clrbit(void __iomem *addr, u32 offset, u32 bitmask)
203 {
204 	u32 val;
205 	val = ioread32(addr + offset);
206 	val &= (~bitmask);
207 	iowrite32(val, addr + offset);
208 }
209 
210 /**
211  * pch_i2c_init() - hardware initialization of I2C module
212  * @adap:	Pointer to struct i2c_algo_pch_data.
213  */
214 static void pch_i2c_init(struct i2c_algo_pch_data *adap)
215 {
216 	void __iomem *p = adap->pch_base_address;
217 	u32 pch_i2cbc;
218 	u32 pch_i2ctmr;
219 	u32 reg_value;
220 
221 	/* reset I2C controller */
222 	iowrite32(0x01, p + PCH_I2CSRST);
223 	msleep(20);
224 	iowrite32(0x0, p + PCH_I2CSRST);
225 
226 	/* Initialize I2C registers */
227 	iowrite32(0x21, p + PCH_I2CNF);
228 
229 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_I2CCTL_I2CMEN);
230 
231 	if (pch_i2c_speed != 400)
232 		pch_i2c_speed = 100;
233 
234 	reg_value = PCH_I2CCTL_I2CMEN;
235 	if (pch_i2c_speed == FAST_MODE_CLK) {
236 		reg_value |= FAST_MODE_EN;
237 		pch_dbg(adap, "Fast mode enabled\n");
238 	}
239 
240 	if (pch_clk > PCH_MAX_CLK)
241 		pch_clk = 62500;
242 
243 	pch_i2cbc = (pch_clk + (pch_i2c_speed * 4)) / pch_i2c_speed * 8;
244 	/* Set transfer speed in I2CBC */
245 	iowrite32(pch_i2cbc, p + PCH_I2CBC);
246 
247 	pch_i2ctmr = (pch_clk) / 8;
248 	iowrite32(pch_i2ctmr, p + PCH_I2CTMR);
249 
250 	reg_value |= NORMAL_INTR_ENBL;	/* Enable interrupts in normal mode */
251 	iowrite32(reg_value, p + PCH_I2CCTL);
252 
253 	pch_dbg(adap,
254 		"I2CCTL=%x pch_i2cbc=%x pch_i2ctmr=%x Enable interrupts\n",
255 		ioread32(p + PCH_I2CCTL), pch_i2cbc, pch_i2ctmr);
256 
257 	init_waitqueue_head(&pch_event);
258 }
259 
260 static inline bool ktime_lt(const ktime_t cmp1, const ktime_t cmp2)
261 {
262 	return cmp1.tv64 < cmp2.tv64;
263 }
264 
265 /**
266  * pch_i2c_wait_for_bus_idle() - check the status of bus.
267  * @adap:	Pointer to struct i2c_algo_pch_data.
268  * @timeout:	waiting time counter (us).
269  */
270 static s32 pch_i2c_wait_for_bus_idle(struct i2c_algo_pch_data *adap,
271 				     s32 timeout)
272 {
273 	void __iomem *p = adap->pch_base_address;
274 
275 	/* MAX timeout value is timeout*1000*1000nsec */
276 	ktime_t ns_val = ktime_add_ns(ktime_get(), timeout*1000*1000);
277 	do {
278 		if ((ioread32(p + PCH_I2CSR) & I2CMBB_BIT) == 0)
279 			break;
280 		msleep(20);
281 	} while (ktime_lt(ktime_get(), ns_val));
282 
283 	pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
284 
285 	if (timeout == 0) {
286 		pch_err(adap, "%s: Timeout Error.return%d\n", __func__, -ETIME);
287 		return -ETIME;
288 	}
289 
290 	return 0;
291 }
292 
293 /**
294  * pch_i2c_start() - Generate I2C start condition in normal mode.
295  * @adap:	Pointer to struct i2c_algo_pch_data.
296  *
297  * Generate I2C start condition in normal mode by setting I2CCTL.I2CMSTA to 1.
298  */
299 static void pch_i2c_start(struct i2c_algo_pch_data *adap)
300 {
301 	void __iomem *p = adap->pch_base_address;
302 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
303 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
304 }
305 
306 /**
307  * pch_i2c_wait_for_xfer_complete() - initiates a wait for the tx complete event
308  * @adap:	Pointer to struct i2c_algo_pch_data.
309  */
310 static s32 pch_i2c_wait_for_xfer_complete(struct i2c_algo_pch_data *adap)
311 {
312 	s32 ret;
313 	ret = wait_event_timeout(pch_event,
314 			(adap->pch_event_flag != 0), msecs_to_jiffies(50));
315 	if (ret < 0) {
316 		pch_err(adap, "timeout: %x\n", adap->pch_event_flag);
317 		return ret;
318 	}
319 
320 	if (ret == 0) {
321 		pch_err(adap, "timeout: %x\n", adap->pch_event_flag);
322 		return -ETIMEDOUT;
323 	}
324 
325 	if (adap->pch_event_flag & I2C_ERROR_MASK) {
326 		pch_err(adap, "error bits set: %x\n", adap->pch_event_flag);
327 		return -EIO;
328 	}
329 
330 	adap->pch_event_flag = 0;
331 
332 	return 0;
333 }
334 
335 /**
336  * pch_i2c_getack() - to confirm ACK/NACK
337  * @adap:	Pointer to struct i2c_algo_pch_data.
338  */
339 static s32 pch_i2c_getack(struct i2c_algo_pch_data *adap)
340 {
341 	u32 reg_val;
342 	void __iomem *p = adap->pch_base_address;
343 	reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
344 
345 	if (reg_val != 0) {
346 		pch_err(adap, "return%d\n", -EPROTO);
347 		return -EPROTO;
348 	}
349 
350 	return 0;
351 }
352 
353 /**
354  * pch_i2c_stop() - generate stop condition in normal mode.
355  * @adap:	Pointer to struct i2c_algo_pch_data.
356  */
357 static void pch_i2c_stop(struct i2c_algo_pch_data *adap)
358 {
359 	void __iomem *p = adap->pch_base_address;
360 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
361 	/* clear the start bit */
362 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
363 }
364 
365 /**
366  * pch_i2c_repstart() - generate repeated start condition in normal mode
367  * @adap:	Pointer to struct i2c_algo_pch_data.
368  */
369 static void pch_i2c_repstart(struct i2c_algo_pch_data *adap)
370 {
371 	void __iomem *p = adap->pch_base_address;
372 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
373 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_REPSTART);
374 }
375 
376 /**
377  * pch_i2c_writebytes() - write data to I2C bus in normal mode
378  * @i2c_adap:	Pointer to the struct i2c_adapter.
379  * @last:	specifies whether last message or not.
380  *		In the case of compound mode it will be 1 for last message,
381  *		otherwise 0.
382  * @first:	specifies whether first message or not.
383  *		1 for first message otherwise 0.
384  */
385 static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
386 			      struct i2c_msg *msgs, u32 last, u32 first)
387 {
388 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
389 	u8 *buf;
390 	u32 length;
391 	u32 addr;
392 	u32 addr_2_msb;
393 	u32 addr_8_lsb;
394 	s32 wrcount;
395 	void __iomem *p = adap->pch_base_address;
396 
397 	length = msgs->len;
398 	buf = msgs->buf;
399 	addr = msgs->addr;
400 
401 	/* enable master tx */
402 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
403 
404 	pch_dbg(adap, "I2CCTL = %x msgs->len = %d\n", ioread32(p + PCH_I2CCTL),
405 		length);
406 
407 	if (first) {
408 		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
409 			return -ETIME;
410 	}
411 
412 	if (msgs->flags & I2C_M_TEN) {
413 		addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7);
414 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
415 		if (first)
416 			pch_i2c_start(adap);
417 		if (pch_i2c_wait_for_xfer_complete(adap) == 0 &&
418 		    pch_i2c_getack(adap) == 0) {
419 			addr_8_lsb = (addr & I2C_ADDR_MSK);
420 			iowrite32(addr_8_lsb, p + PCH_I2CDR);
421 		} else {
422 			pch_i2c_stop(adap);
423 			return -ETIME;
424 		}
425 	} else {
426 		/* set 7 bit slave address and R/W bit as 0 */
427 		iowrite32(addr << 1, p + PCH_I2CDR);
428 		if (first)
429 			pch_i2c_start(adap);
430 	}
431 
432 	if ((pch_i2c_wait_for_xfer_complete(adap) == 0) &&
433 	    (pch_i2c_getack(adap) == 0)) {
434 		for (wrcount = 0; wrcount < length; ++wrcount) {
435 			/* write buffer value to I2C data register */
436 			iowrite32(buf[wrcount], p + PCH_I2CDR);
437 			pch_dbg(adap, "writing %x to Data register\n",
438 				buf[wrcount]);
439 
440 			if (pch_i2c_wait_for_xfer_complete(adap) != 0)
441 				return -ETIME;
442 
443 			if (pch_i2c_getack(adap))
444 				return -EIO;
445 		}
446 
447 		/* check if this is the last message */
448 		if (last)
449 			pch_i2c_stop(adap);
450 		else
451 			pch_i2c_repstart(adap);
452 	} else {
453 		pch_i2c_stop(adap);
454 		return -EIO;
455 	}
456 
457 	pch_dbg(adap, "return=%d\n", wrcount);
458 
459 	return wrcount;
460 }
461 
462 /**
463  * pch_i2c_sendack() - send ACK
464  * @adap:	Pointer to struct i2c_algo_pch_data.
465  */
466 static void pch_i2c_sendack(struct i2c_algo_pch_data *adap)
467 {
468 	void __iomem *p = adap->pch_base_address;
469 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
470 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
471 }
472 
473 /**
474  * pch_i2c_sendnack() - send NACK
475  * @adap:	Pointer to struct i2c_algo_pch_data.
476  */
477 static void pch_i2c_sendnack(struct i2c_algo_pch_data *adap)
478 {
479 	void __iomem *p = adap->pch_base_address;
480 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
481 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
482 }
483 
484 /**
485  * pch_i2c_readbytes() - read data  from I2C bus in normal mode.
486  * @i2c_adap:	Pointer to the struct i2c_adapter.
487  * @msgs:	Pointer to i2c_msg structure.
488  * @last:	specifies whether last message or not.
489  * @first:	specifies whether first message or not.
490  */
491 static s32 pch_i2c_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
492 			     u32 last, u32 first)
493 {
494 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
495 
496 	u8 *buf;
497 	u32 count;
498 	u32 length;
499 	u32 addr;
500 	u32 addr_2_msb;
501 	void __iomem *p = adap->pch_base_address;
502 
503 	length = msgs->len;
504 	buf = msgs->buf;
505 	addr = msgs->addr;
506 
507 	/* enable master reception */
508 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
509 
510 	if (first) {
511 		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
512 			return -ETIME;
513 	}
514 
515 	if (msgs->flags & I2C_M_TEN) {
516 		addr_2_msb = (((addr & I2C_MSB_2B_MSK) >> 7) | (I2C_RD));
517 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
518 
519 	} else {
520 		/* 7 address bits + R/W bit */
521 		addr = (((addr) << 1) | (I2C_RD));
522 		iowrite32(addr, p + PCH_I2CDR);
523 	}
524 
525 	/* check if it is the first message */
526 	if (first)
527 		pch_i2c_start(adap);
528 
529 	if ((pch_i2c_wait_for_xfer_complete(adap) == 0) &&
530 	    (pch_i2c_getack(adap) == 0)) {
531 		pch_dbg(adap, "return %d\n", 0);
532 
533 		if (length == 0) {
534 			pch_i2c_stop(adap);
535 			ioread32(p + PCH_I2CDR); /* Dummy read needs */
536 
537 			count = length;
538 		} else {
539 			int read_index;
540 			int loop;
541 			pch_i2c_sendack(adap);
542 
543 			/* Dummy read */
544 			for (loop = 1, read_index = 0; loop < length; loop++) {
545 				buf[read_index] = ioread32(p + PCH_I2CDR);
546 
547 				if (loop != 1)
548 					read_index++;
549 
550 				if (pch_i2c_wait_for_xfer_complete(adap) != 0) {
551 					pch_i2c_stop(adap);
552 					return -ETIME;
553 				}
554 			}	/* end for */
555 
556 			pch_i2c_sendnack(adap);
557 
558 			buf[read_index] = ioread32(p + PCH_I2CDR);
559 
560 			if (length != 1)
561 				read_index++;
562 
563 			if (pch_i2c_wait_for_xfer_complete(adap) == 0) {
564 				if (last)
565 					pch_i2c_stop(adap);
566 				else
567 					pch_i2c_repstart(adap);
568 
569 				buf[read_index++] = ioread32(p + PCH_I2CDR);
570 				count = read_index;
571 			} else {
572 				count = -ETIME;
573 			}
574 
575 		}
576 	} else {
577 		count = -ETIME;
578 		pch_i2c_stop(adap);
579 	}
580 
581 	return count;
582 }
583 
584 /**
585  * pch_i2c_cb() - Interrupt handler Call back function
586  * @adap:	Pointer to struct i2c_algo_pch_data.
587  */
588 static void pch_i2c_cb(struct i2c_algo_pch_data *adap)
589 {
590 	u32 sts;
591 	void __iomem *p = adap->pch_base_address;
592 
593 	sts = ioread32(p + PCH_I2CSR);
594 	sts &= (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT);
595 	if (sts & I2CMAL_BIT)
596 		adap->pch_event_flag |= I2CMAL_EVENT;
597 
598 	if (sts & I2CMCF_BIT)
599 		adap->pch_event_flag |= I2CMCF_EVENT;
600 
601 	/* clear the applicable bits */
602 	pch_clrbit(adap->pch_base_address, PCH_I2CSR, sts);
603 
604 	pch_dbg(adap, "PCH_I2CSR = %x\n", ioread32(p + PCH_I2CSR));
605 
606 	wake_up(&pch_event);
607 }
608 
609 /**
610  * pch_i2c_handler() - interrupt handler for the PCH I2C controller
611  * @irq:	irq number.
612  * @pData:	cookie passed back to the handler function.
613  */
614 static irqreturn_t pch_i2c_handler(int irq, void *pData)
615 {
616 	u32 reg_val;
617 	int flag;
618 	int i;
619 	struct adapter_info *adap_info = pData;
620 	void __iomem *p;
621 	u32 mode;
622 
623 	for (i = 0, flag = 0; i < adap_info->ch_num; i++) {
624 		p = adap_info->pch_data[i].pch_base_address;
625 		mode = ioread32(p + PCH_I2CMOD);
626 		mode &= BUFFER_MODE | EEPROM_SR_MODE;
627 		if (mode != NORMAL_MODE) {
628 			pch_err(adap_info->pch_data,
629 				"I2C-%d mode(%d) is not supported\n", mode, i);
630 			continue;
631 		}
632 		reg_val = ioread32(p + PCH_I2CSR);
633 		if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT)) {
634 			pch_i2c_cb(&adap_info->pch_data[i]);
635 			flag = 1;
636 		}
637 	}
638 
639 	return flag ? IRQ_HANDLED : IRQ_NONE;
640 }
641 
642 /**
643  * pch_i2c_xfer() - Reading adnd writing data through I2C bus
644  * @i2c_adap:	Pointer to the struct i2c_adapter.
645  * @msgs:	Pointer to i2c_msg structure.
646  * @num:	number of messages.
647  */
648 static s32 pch_i2c_xfer(struct i2c_adapter *i2c_adap,
649 			struct i2c_msg *msgs, s32 num)
650 {
651 	struct i2c_msg *pmsg;
652 	u32 i = 0;
653 	u32 status;
654 	u32 msglen;
655 	u32 subaddrlen;
656 	s32 ret;
657 
658 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
659 
660 	ret = mutex_lock_interruptible(&pch_mutex);
661 	if (ret)
662 		return -ERESTARTSYS;
663 
664 	if (adap->p_adapter_info->pch_i2c_suspended) {
665 		mutex_unlock(&pch_mutex);
666 		return -EBUSY;
667 	}
668 
669 	pch_dbg(adap, "adap->p_adapter_info->pch_i2c_suspended is %d\n",
670 		adap->p_adapter_info->pch_i2c_suspended);
671 	/* transfer not completed */
672 	adap->pch_i2c_xfer_in_progress = true;
673 
674 	pmsg = &msgs[0];
675 	pmsg->flags |= adap->pch_buff_mode_en;
676 	status = pmsg->flags;
677 	pch_dbg(adap,
678 		"After invoking I2C_MODE_SEL :flag= 0x%x\n", status);
679 	/* calculate sub address length and message length */
680 	/* these are applicable only for buffer mode */
681 	subaddrlen = pmsg->buf[0];
682 	/* calculate actual message length excluding
683 	 * the sub address fields */
684 	msglen = (pmsg->len) - (subaddrlen + 1);
685 	if (status & (I2C_M_RD)) {
686 		pch_dbg(adap, "invoking pch_i2c_readbytes\n");
687 		ret = pch_i2c_readbytes(i2c_adap, pmsg, (i + 1 == num),
688 				   (i == 0));
689 	} else {
690 		pch_dbg(adap, "invoking pch_i2c_writebytes\n");
691 		ret = pch_i2c_writebytes(i2c_adap, pmsg, (i + 1 == num),
692 				    (i == 0));
693 	}
694 
695 	adap->pch_i2c_xfer_in_progress = false;	/* transfer completed */
696 
697 	mutex_unlock(&pch_mutex);
698 
699 	return ret;
700 }
701 
702 /**
703  * pch_i2c_func() - return the functionality of the I2C driver
704  * @adap:	Pointer to struct i2c_algo_pch_data.
705  */
706 static u32 pch_i2c_func(struct i2c_adapter *adap)
707 {
708 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
709 }
710 
711 static struct i2c_algorithm pch_algorithm = {
712 	.master_xfer = pch_i2c_xfer,
713 	.functionality = pch_i2c_func
714 };
715 
716 /**
717  * pch_i2c_disbl_int() - Disable PCH I2C interrupts
718  * @adap:	Pointer to struct i2c_algo_pch_data.
719  */
720 static void pch_i2c_disbl_int(struct i2c_algo_pch_data *adap)
721 {
722 	void __iomem *p = adap->pch_base_address;
723 
724 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, NORMAL_INTR_ENBL);
725 
726 	iowrite32(EEPROM_RST_INTR_DISBL, p + PCH_I2CESRMSK);
727 
728 	iowrite32(BUFFER_MODE_INTR_DISBL, p + PCH_I2CBUFMSK);
729 }
730 
731 static int __devinit pch_i2c_probe(struct pci_dev *pdev,
732 				   const struct pci_device_id *id)
733 {
734 	void __iomem *base_addr;
735 	int ret;
736 	int i, j;
737 	struct adapter_info *adap_info;
738 	struct i2c_adapter *pch_adap;
739 
740 	pch_pci_dbg(pdev, "Entered.\n");
741 
742 	adap_info = kzalloc((sizeof(struct adapter_info)), GFP_KERNEL);
743 	if (adap_info == NULL) {
744 		pch_pci_err(pdev, "Memory allocation FAILED\n");
745 		return -ENOMEM;
746 	}
747 
748 	ret = pci_enable_device(pdev);
749 	if (ret) {
750 		pch_pci_err(pdev, "pci_enable_device FAILED\n");
751 		goto err_pci_enable;
752 	}
753 
754 	ret = pci_request_regions(pdev, KBUILD_MODNAME);
755 	if (ret) {
756 		pch_pci_err(pdev, "pci_request_regions FAILED\n");
757 		goto err_pci_req;
758 	}
759 
760 	base_addr = pci_iomap(pdev, 1, 0);
761 
762 	if (base_addr == NULL) {
763 		pch_pci_err(pdev, "pci_iomap FAILED\n");
764 		ret = -ENOMEM;
765 		goto err_pci_iomap;
766 	}
767 
768 	/* Set the number of I2C channel instance */
769 	adap_info->ch_num = id->driver_data;
770 
771 	for (i = 0; i < adap_info->ch_num; i++) {
772 		pch_adap = &adap_info->pch_data[i].pch_adapter;
773 		adap_info->pch_i2c_suspended = false;
774 
775 		adap_info->pch_data[i].p_adapter_info = adap_info;
776 
777 		pch_adap->owner = THIS_MODULE;
778 		pch_adap->class = I2C_CLASS_HWMON;
779 		strcpy(pch_adap->name, KBUILD_MODNAME);
780 		pch_adap->algo = &pch_algorithm;
781 		pch_adap->algo_data = &adap_info->pch_data[i];
782 
783 		/* base_addr + offset; */
784 		adap_info->pch_data[i].pch_base_address = base_addr + 0x100 * i;
785 
786 		pch_adap->dev.parent = &pdev->dev;
787 
788 		ret = i2c_add_adapter(pch_adap);
789 		if (ret) {
790 			pch_pci_err(pdev, "i2c_add_adapter[ch:%d] FAILED\n", i);
791 			goto err_i2c_add_adapter;
792 		}
793 
794 		pch_i2c_init(&adap_info->pch_data[i]);
795 	}
796 	ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED,
797 		  KBUILD_MODNAME, adap_info);
798 	if (ret) {
799 		pch_pci_err(pdev, "request_irq FAILED\n");
800 		goto err_i2c_add_adapter;
801 	}
802 
803 	pci_set_drvdata(pdev, adap_info);
804 	pch_pci_dbg(pdev, "returns %d.\n", ret);
805 	return 0;
806 
807 err_i2c_add_adapter:
808 	for (j = 0; j < i; j++)
809 		i2c_del_adapter(&adap_info->pch_data[j].pch_adapter);
810 	pci_iounmap(pdev, base_addr);
811 err_pci_iomap:
812 	pci_release_regions(pdev);
813 err_pci_req:
814 	pci_disable_device(pdev);
815 err_pci_enable:
816 	kfree(adap_info);
817 	return ret;
818 }
819 
820 static void __devexit pch_i2c_remove(struct pci_dev *pdev)
821 {
822 	int i;
823 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
824 
825 	free_irq(pdev->irq, adap_info);
826 
827 	for (i = 0; i < adap_info->ch_num; i++) {
828 		pch_i2c_disbl_int(&adap_info->pch_data[i]);
829 		i2c_del_adapter(&adap_info->pch_data[i].pch_adapter);
830 	}
831 
832 	if (adap_info->pch_data[0].pch_base_address)
833 		pci_iounmap(pdev, adap_info->pch_data[0].pch_base_address);
834 
835 	for (i = 0; i < adap_info->ch_num; i++)
836 		adap_info->pch_data[i].pch_base_address = 0;
837 
838 	pci_set_drvdata(pdev, NULL);
839 
840 	pci_release_regions(pdev);
841 
842 	pci_disable_device(pdev);
843 	kfree(adap_info);
844 }
845 
846 #ifdef CONFIG_PM
847 static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
848 {
849 	int ret;
850 	int i;
851 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
852 	void __iomem *p = adap_info->pch_data[0].pch_base_address;
853 
854 	adap_info->pch_i2c_suspended = true;
855 
856 	for (i = 0; i < adap_info->ch_num; i++) {
857 		while ((adap_info->pch_data[i].pch_i2c_xfer_in_progress)) {
858 			/* Wait until all channel transfers are completed */
859 			msleep(20);
860 		}
861 	}
862 
863 	/* Disable the i2c interrupts */
864 	for (i = 0; i < adap_info->ch_num; i++)
865 		pch_i2c_disbl_int(&adap_info->pch_data[i]);
866 
867 	pch_pci_dbg(pdev, "I2CSR = %x I2CBUFSTA = %x I2CESRSTA = %x "
868 		"invoked function pch_i2c_disbl_int successfully\n",
869 		ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
870 		ioread32(p + PCH_I2CESRSTA));
871 
872 	ret = pci_save_state(pdev);
873 
874 	if (ret) {
875 		pch_pci_err(pdev, "pci_save_state\n");
876 		return ret;
877 	}
878 
879 	pci_enable_wake(pdev, PCI_D3hot, 0);
880 	pci_disable_device(pdev);
881 	pci_set_power_state(pdev, pci_choose_state(pdev, state));
882 
883 	return 0;
884 }
885 
886 static int pch_i2c_resume(struct pci_dev *pdev)
887 {
888 	int i;
889 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
890 
891 	pci_set_power_state(pdev, PCI_D0);
892 	pci_restore_state(pdev);
893 
894 	if (pci_enable_device(pdev) < 0) {
895 		pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
896 		return -EIO;
897 	}
898 
899 	pci_enable_wake(pdev, PCI_D3hot, 0);
900 
901 	for (i = 0; i < adap_info->ch_num; i++)
902 		pch_i2c_init(&adap_info->pch_data[i]);
903 
904 	adap_info->pch_i2c_suspended = false;
905 
906 	return 0;
907 }
908 #else
909 #define pch_i2c_suspend NULL
910 #define pch_i2c_resume NULL
911 #endif
912 
913 static struct pci_driver pch_pcidriver = {
914 	.name = KBUILD_MODNAME,
915 	.id_table = pch_pcidev_id,
916 	.probe = pch_i2c_probe,
917 	.remove = __devexit_p(pch_i2c_remove),
918 	.suspend = pch_i2c_suspend,
919 	.resume = pch_i2c_resume
920 };
921 
922 static int __init pch_pci_init(void)
923 {
924 	return pci_register_driver(&pch_pcidriver);
925 }
926 module_init(pch_pci_init);
927 
928 static void __exit pch_pci_exit(void)
929 {
930 	pci_unregister_driver(&pch_pcidriver);
931 }
932 module_exit(pch_pci_exit);
933 
934 MODULE_DESCRIPTION("Intel EG20T PCH/OKI SEMICONDUCTOR ML7213 IOH I2C Driver");
935 MODULE_LICENSE("GPL");
936 MODULE_AUTHOR("Tomoya MORINAGA. <tomoya-linux@dsn.okisemi.com>");
937 module_param(pch_i2c_speed, int, (S_IRUSR | S_IWUSR));
938 module_param(pch_clk, int, (S_IRUSR | S_IWUSR));
939