xref: /openbmc/linux/drivers/i2c/busses/i2c-eg20t.c (revision 33a03aad)
1 /*
2  * Copyright (C) 2011 LAPIS 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_RESTART		0x0004
68 #define PCH_ESR_START		0x0001
69 #define PCH_BUFF_START		0x1
70 #define PCH_REPSTART		0x0004
71 #define PCH_ACK			0x0008
72 #define PCH_GETACK		0x0001
73 #define CLR_REG			0x0
74 #define I2C_RD			0x1
75 #define I2CMCF_BIT		0x0080
76 #define I2CMIF_BIT		0x0002
77 #define I2CMAL_BIT		0x0010
78 #define I2CBMFI_BIT		0x0001
79 #define I2CBMAL_BIT		0x0002
80 #define I2CBMNA_BIT		0x0004
81 #define I2CBMTO_BIT		0x0008
82 #define I2CBMIS_BIT		0x0010
83 #define I2CESRFI_BIT		0X0001
84 #define I2CESRTO_BIT		0x0002
85 #define I2CESRFIIE_BIT		0x1
86 #define I2CESRTOIE_BIT		0x2
87 #define I2CBMDZ_BIT		0x0040
88 #define I2CBMAG_BIT		0x0020
89 #define I2CMBB_BIT		0x0020
90 #define BUFFER_MODE_MASK	(I2CBMFI_BIT | I2CBMAL_BIT | I2CBMNA_BIT | \
91 				I2CBMTO_BIT | I2CBMIS_BIT)
92 #define I2C_ADDR_MSK		0xFF
93 #define I2C_MSB_2B_MSK		0x300
94 #define FAST_MODE_CLK		400
95 #define FAST_MODE_EN		0x0001
96 #define SUB_ADDR_LEN_MAX	4
97 #define BUF_LEN_MAX		32
98 #define PCH_BUFFER_MODE		0x1
99 #define EEPROM_SW_RST_MODE	0x0002
100 #define NORMAL_INTR_ENBL	0x0300
101 #define EEPROM_RST_INTR_ENBL	(I2CESRFIIE_BIT | I2CESRTOIE_BIT)
102 #define EEPROM_RST_INTR_DISBL	0x0
103 #define BUFFER_MODE_INTR_ENBL	0x001F
104 #define BUFFER_MODE_INTR_DISBL	0x0
105 #define NORMAL_MODE		0x0
106 #define BUFFER_MODE		0x1
107 #define EEPROM_SR_MODE		0x2
108 #define I2C_TX_MODE		0x0010
109 #define PCH_BUF_TX		0xFFF7
110 #define PCH_BUF_RD		0x0008
111 #define I2C_ERROR_MASK	(I2CESRTO_EVENT | I2CBMIS_EVENT | I2CBMTO_EVENT | \
112 			I2CBMNA_EVENT | I2CBMAL_EVENT | I2CMAL_EVENT)
113 #define I2CMAL_EVENT		0x0001
114 #define I2CMCF_EVENT		0x0002
115 #define I2CBMFI_EVENT		0x0004
116 #define I2CBMAL_EVENT		0x0008
117 #define I2CBMNA_EVENT		0x0010
118 #define I2CBMTO_EVENT		0x0020
119 #define I2CBMIS_EVENT		0x0040
120 #define I2CESRFI_EVENT		0x0080
121 #define I2CESRTO_EVENT		0x0100
122 #define PCI_DEVICE_ID_PCH_I2C	0x8817
123 
124 #define pch_dbg(adap, fmt, arg...)  \
125 	dev_dbg(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
126 
127 #define pch_err(adap, fmt, arg...)  \
128 	dev_err(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
129 
130 #define pch_pci_err(pdev, fmt, arg...)  \
131 	dev_err(&pdev->dev, "%s :" fmt, __func__, ##arg)
132 
133 #define pch_pci_dbg(pdev, fmt, arg...)  \
134 	dev_dbg(&pdev->dev, "%s :" fmt, __func__, ##arg)
135 
136 /*
137 Set the number of I2C instance max
138 Intel EG20T PCH :		1ch
139 LAPIS Semiconductor ML7213 IOH :	2ch
140 LAPIS Semiconductor ML7831 IOH :	1ch
141 */
142 #define PCH_I2C_MAX_DEV			2
143 
144 /**
145  * struct i2c_algo_pch_data - for I2C driver functionalities
146  * @pch_adapter:		stores the reference to i2c_adapter structure
147  * @p_adapter_info:		stores the reference to adapter_info structure
148  * @pch_base_address:		specifies the remapped base address
149  * @pch_buff_mode_en:		specifies if buffer mode is enabled
150  * @pch_event_flag:		specifies occurrence of interrupt events
151  * @pch_i2c_xfer_in_progress:	specifies whether the transfer is completed
152  */
153 struct i2c_algo_pch_data {
154 	struct i2c_adapter pch_adapter;
155 	struct adapter_info *p_adapter_info;
156 	void __iomem *pch_base_address;
157 	int pch_buff_mode_en;
158 	u32 pch_event_flag;
159 	bool pch_i2c_xfer_in_progress;
160 };
161 
162 /**
163  * struct adapter_info - This structure holds the adapter information for the
164 			 PCH i2c controller
165  * @pch_data:		stores a list of i2c_algo_pch_data
166  * @pch_i2c_suspended:	specifies whether the system is suspended or not
167  *			perhaps with more lines and words.
168  * @ch_num:		specifies the number of i2c instance
169  *
170  * pch_data has as many elements as maximum I2C channels
171  */
172 struct adapter_info {
173 	struct i2c_algo_pch_data pch_data[PCH_I2C_MAX_DEV];
174 	bool pch_i2c_suspended;
175 	int ch_num;
176 };
177 
178 
179 static int pch_i2c_speed = 100; /* I2C bus speed in Kbps */
180 static int pch_clk = 50000;	/* specifies I2C clock speed in KHz */
181 static wait_queue_head_t pch_event;
182 static DEFINE_MUTEX(pch_mutex);
183 
184 /* Definition for ML7213 by LAPIS Semiconductor */
185 #define PCI_VENDOR_ID_ROHM		0x10DB
186 #define PCI_DEVICE_ID_ML7213_I2C	0x802D
187 #define PCI_DEVICE_ID_ML7223_I2C	0x8010
188 #define PCI_DEVICE_ID_ML7831_I2C	0x8817
189 
190 static DEFINE_PCI_DEVICE_TABLE(pch_pcidev_id) = {
191 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PCH_I2C),   1, },
192 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_I2C), 2, },
193 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_I2C), 1, },
194 	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_I2C), 1, },
195 	{0,}
196 };
197 
198 static irqreturn_t pch_i2c_handler(int irq, void *pData);
199 
200 static inline void pch_setbit(void __iomem *addr, u32 offset, u32 bitmask)
201 {
202 	u32 val;
203 	val = ioread32(addr + offset);
204 	val |= bitmask;
205 	iowrite32(val, addr + offset);
206 }
207 
208 static inline void pch_clrbit(void __iomem *addr, u32 offset, u32 bitmask)
209 {
210 	u32 val;
211 	val = ioread32(addr + offset);
212 	val &= (~bitmask);
213 	iowrite32(val, addr + offset);
214 }
215 
216 /**
217  * pch_i2c_init() - hardware initialization of I2C module
218  * @adap:	Pointer to struct i2c_algo_pch_data.
219  */
220 static void pch_i2c_init(struct i2c_algo_pch_data *adap)
221 {
222 	void __iomem *p = adap->pch_base_address;
223 	u32 pch_i2cbc;
224 	u32 pch_i2ctmr;
225 	u32 reg_value;
226 
227 	/* reset I2C controller */
228 	iowrite32(0x01, p + PCH_I2CSRST);
229 	msleep(20);
230 	iowrite32(0x0, p + PCH_I2CSRST);
231 
232 	/* Initialize I2C registers */
233 	iowrite32(0x21, p + PCH_I2CNF);
234 
235 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_I2CCTL_I2CMEN);
236 
237 	if (pch_i2c_speed != 400)
238 		pch_i2c_speed = 100;
239 
240 	reg_value = PCH_I2CCTL_I2CMEN;
241 	if (pch_i2c_speed == FAST_MODE_CLK) {
242 		reg_value |= FAST_MODE_EN;
243 		pch_dbg(adap, "Fast mode enabled\n");
244 	}
245 
246 	if (pch_clk > PCH_MAX_CLK)
247 		pch_clk = 62500;
248 
249 	pch_i2cbc = (pch_clk + (pch_i2c_speed * 4)) / (pch_i2c_speed * 8);
250 	/* Set transfer speed in I2CBC */
251 	iowrite32(pch_i2cbc, p + PCH_I2CBC);
252 
253 	pch_i2ctmr = (pch_clk) / 8;
254 	iowrite32(pch_i2ctmr, p + PCH_I2CTMR);
255 
256 	reg_value |= NORMAL_INTR_ENBL;	/* Enable interrupts in normal mode */
257 	iowrite32(reg_value, p + PCH_I2CCTL);
258 
259 	pch_dbg(adap,
260 		"I2CCTL=%x pch_i2cbc=%x pch_i2ctmr=%x Enable interrupts\n",
261 		ioread32(p + PCH_I2CCTL), pch_i2cbc, pch_i2ctmr);
262 
263 	init_waitqueue_head(&pch_event);
264 }
265 
266 /**
267  * pch_i2c_wait_for_bus_idle() - check the status of bus.
268  * @adap:	Pointer to struct i2c_algo_pch_data.
269  * @timeout:	waiting time counter (ms).
270  */
271 static s32 pch_i2c_wait_for_bus_idle(struct i2c_algo_pch_data *adap,
272 				     s32 timeout)
273 {
274 	void __iomem *p = adap->pch_base_address;
275 	int schedule = 0;
276 	unsigned long end = jiffies + msecs_to_jiffies(timeout);
277 
278 	while (ioread32(p + PCH_I2CSR) & I2CMBB_BIT) {
279 		if (time_after(jiffies, end)) {
280 			pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
281 			pch_err(adap, "%s: Timeout Error.return%d\n",
282 					__func__, -ETIME);
283 			pch_i2c_init(adap);
284 
285 			return -ETIME;
286 		}
287 
288 		if (!schedule)
289 			/* Retry after some usecs */
290 			udelay(5);
291 		else
292 			/* Wait a bit more without consuming CPU */
293 			usleep_range(20, 1000);
294 
295 		schedule = 1;
296 	}
297 
298 	return 0;
299 }
300 
301 /**
302  * pch_i2c_start() - Generate I2C start condition in normal mode.
303  * @adap:	Pointer to struct i2c_algo_pch_data.
304  *
305  * Generate I2C start condition in normal mode by setting I2CCTL.I2CMSTA to 1.
306  */
307 static void pch_i2c_start(struct i2c_algo_pch_data *adap)
308 {
309 	void __iomem *p = adap->pch_base_address;
310 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
311 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
312 }
313 
314 /**
315  * pch_i2c_getack() - to confirm ACK/NACK
316  * @adap:	Pointer to struct i2c_algo_pch_data.
317  */
318 static s32 pch_i2c_getack(struct i2c_algo_pch_data *adap)
319 {
320 	u32 reg_val;
321 	void __iomem *p = adap->pch_base_address;
322 	reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
323 
324 	if (reg_val != 0) {
325 		pch_err(adap, "return%d\n", -EPROTO);
326 		return -EPROTO;
327 	}
328 
329 	return 0;
330 }
331 
332 /**
333  * pch_i2c_stop() - generate stop condition in normal mode.
334  * @adap:	Pointer to struct i2c_algo_pch_data.
335  */
336 static void pch_i2c_stop(struct i2c_algo_pch_data *adap)
337 {
338 	void __iomem *p = adap->pch_base_address;
339 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
340 	/* clear the start bit */
341 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
342 }
343 
344 static int pch_i2c_wait_for_check_xfer(struct i2c_algo_pch_data *adap)
345 {
346 	long ret;
347 
348 	ret = wait_event_timeout(pch_event,
349 			(adap->pch_event_flag != 0), msecs_to_jiffies(1000));
350 	if (!ret) {
351 		pch_err(adap, "%s:wait-event timeout\n", __func__);
352 		adap->pch_event_flag = 0;
353 		pch_i2c_stop(adap);
354 		pch_i2c_init(adap);
355 		return -ETIMEDOUT;
356 	}
357 
358 	if (adap->pch_event_flag & I2C_ERROR_MASK) {
359 		pch_err(adap, "Lost Arbitration\n");
360 		adap->pch_event_flag = 0;
361 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
362 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
363 		pch_i2c_init(adap);
364 		return -EAGAIN;
365 	}
366 
367 	adap->pch_event_flag = 0;
368 
369 	if (pch_i2c_getack(adap)) {
370 		pch_dbg(adap, "Receive NACK for slave address"
371 			"setting\n");
372 		return -EIO;
373 	}
374 
375 	return 0;
376 }
377 
378 /**
379  * pch_i2c_repstart() - generate repeated start condition in normal mode
380  * @adap:	Pointer to struct i2c_algo_pch_data.
381  */
382 static void pch_i2c_repstart(struct i2c_algo_pch_data *adap)
383 {
384 	void __iomem *p = adap->pch_base_address;
385 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
386 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_REPSTART);
387 }
388 
389 /**
390  * pch_i2c_writebytes() - write data to I2C bus in normal mode
391  * @i2c_adap:	Pointer to the struct i2c_adapter.
392  * @last:	specifies whether last message or not.
393  *		In the case of compound mode it will be 1 for last message,
394  *		otherwise 0.
395  * @first:	specifies whether first message or not.
396  *		1 for first message otherwise 0.
397  */
398 static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
399 			      struct i2c_msg *msgs, u32 last, u32 first)
400 {
401 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
402 	u8 *buf;
403 	u32 length;
404 	u32 addr;
405 	u32 addr_2_msb;
406 	u32 addr_8_lsb;
407 	s32 wrcount;
408 	s32 rtn;
409 	void __iomem *p = adap->pch_base_address;
410 
411 	length = msgs->len;
412 	buf = msgs->buf;
413 	addr = msgs->addr;
414 
415 	/* enable master tx */
416 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
417 
418 	pch_dbg(adap, "I2CCTL = %x msgs->len = %d\n", ioread32(p + PCH_I2CCTL),
419 		length);
420 
421 	if (first) {
422 		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
423 			return -ETIME;
424 	}
425 
426 	if (msgs->flags & I2C_M_TEN) {
427 		addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7) & 0x06;
428 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
429 		if (first)
430 			pch_i2c_start(adap);
431 
432 		rtn = pch_i2c_wait_for_check_xfer(adap);
433 		if (rtn)
434 			return rtn;
435 
436 		addr_8_lsb = (addr & I2C_ADDR_MSK);
437 		iowrite32(addr_8_lsb, p + PCH_I2CDR);
438 	} else {
439 		/* set 7 bit slave address and R/W bit as 0 */
440 		iowrite32(addr << 1, p + PCH_I2CDR);
441 		if (first)
442 			pch_i2c_start(adap);
443 	}
444 
445 	rtn = pch_i2c_wait_for_check_xfer(adap);
446 	if (rtn)
447 		return rtn;
448 
449 	for (wrcount = 0; wrcount < length; ++wrcount) {
450 		/* write buffer value to I2C data register */
451 		iowrite32(buf[wrcount], p + PCH_I2CDR);
452 		pch_dbg(adap, "writing %x to Data register\n", buf[wrcount]);
453 
454 		rtn = pch_i2c_wait_for_check_xfer(adap);
455 		if (rtn)
456 			return rtn;
457 
458 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMCF_BIT);
459 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
460 	}
461 
462 	/* check if this is the last message */
463 	if (last)
464 		pch_i2c_stop(adap);
465 	else
466 		pch_i2c_repstart(adap);
467 
468 	pch_dbg(adap, "return=%d\n", wrcount);
469 
470 	return wrcount;
471 }
472 
473 /**
474  * pch_i2c_sendack() - send ACK
475  * @adap:	Pointer to struct i2c_algo_pch_data.
476  */
477 static void pch_i2c_sendack(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_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
482 }
483 
484 /**
485  * pch_i2c_sendnack() - send NACK
486  * @adap:	Pointer to struct i2c_algo_pch_data.
487  */
488 static void pch_i2c_sendnack(struct i2c_algo_pch_data *adap)
489 {
490 	void __iomem *p = adap->pch_base_address;
491 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
492 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
493 }
494 
495 /**
496  * pch_i2c_restart() - Generate I2C restart condition in normal mode.
497  * @adap:	Pointer to struct i2c_algo_pch_data.
498  *
499  * Generate I2C restart condition in normal mode by setting I2CCTL.I2CRSTA.
500  */
501 static void pch_i2c_restart(struct i2c_algo_pch_data *adap)
502 {
503 	void __iomem *p = adap->pch_base_address;
504 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
505 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_RESTART);
506 }
507 
508 /**
509  * pch_i2c_readbytes() - read data  from I2C bus in normal mode.
510  * @i2c_adap:	Pointer to the struct i2c_adapter.
511  * @msgs:	Pointer to i2c_msg structure.
512  * @last:	specifies whether last message or not.
513  * @first:	specifies whether first message or not.
514  */
515 static s32 pch_i2c_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
516 			     u32 last, u32 first)
517 {
518 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
519 
520 	u8 *buf;
521 	u32 count;
522 	u32 length;
523 	u32 addr;
524 	u32 addr_2_msb;
525 	u32 addr_8_lsb;
526 	void __iomem *p = adap->pch_base_address;
527 	s32 rtn;
528 
529 	length = msgs->len;
530 	buf = msgs->buf;
531 	addr = msgs->addr;
532 
533 	/* enable master reception */
534 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
535 
536 	if (first) {
537 		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
538 			return -ETIME;
539 	}
540 
541 	if (msgs->flags & I2C_M_TEN) {
542 		addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7);
543 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
544 		if (first)
545 			pch_i2c_start(adap);
546 
547 		rtn = pch_i2c_wait_for_check_xfer(adap);
548 		if (rtn)
549 			return rtn;
550 
551 		addr_8_lsb = (addr & I2C_ADDR_MSK);
552 		iowrite32(addr_8_lsb, p + PCH_I2CDR);
553 
554 		pch_i2c_restart(adap);
555 
556 		rtn = pch_i2c_wait_for_check_xfer(adap);
557 		if (rtn)
558 			return rtn;
559 
560 		addr_2_msb |= I2C_RD;
561 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
562 	} else {
563 		/* 7 address bits + R/W bit */
564 		addr = (((addr) << 1) | (I2C_RD));
565 		iowrite32(addr, p + PCH_I2CDR);
566 	}
567 
568 	/* check if it is the first message */
569 	if (first)
570 		pch_i2c_start(adap);
571 
572 	rtn = pch_i2c_wait_for_check_xfer(adap);
573 	if (rtn)
574 		return rtn;
575 
576 	if (length == 0) {
577 		pch_i2c_stop(adap);
578 		ioread32(p + PCH_I2CDR); /* Dummy read needs */
579 
580 		count = length;
581 	} else {
582 		int read_index;
583 		int loop;
584 		pch_i2c_sendack(adap);
585 
586 		/* Dummy read */
587 		for (loop = 1, read_index = 0; loop < length; loop++) {
588 			buf[read_index] = ioread32(p + PCH_I2CDR);
589 
590 			if (loop != 1)
591 				read_index++;
592 
593 			rtn = pch_i2c_wait_for_check_xfer(adap);
594 			if (rtn)
595 				return rtn;
596 		}	/* end for */
597 
598 		pch_i2c_sendnack(adap);
599 
600 		buf[read_index] = ioread32(p + PCH_I2CDR); /* Read final - 1 */
601 
602 		if (length != 1)
603 			read_index++;
604 
605 		rtn = pch_i2c_wait_for_check_xfer(adap);
606 		if (rtn)
607 			return rtn;
608 
609 		if (last)
610 			pch_i2c_stop(adap);
611 		else
612 			pch_i2c_repstart(adap);
613 
614 		buf[read_index++] = ioread32(p + PCH_I2CDR); /* Read Final */
615 		count = read_index;
616 	}
617 
618 	return count;
619 }
620 
621 /**
622  * pch_i2c_cb() - Interrupt handler Call back function
623  * @adap:	Pointer to struct i2c_algo_pch_data.
624  */
625 static void pch_i2c_cb(struct i2c_algo_pch_data *adap)
626 {
627 	u32 sts;
628 	void __iomem *p = adap->pch_base_address;
629 
630 	sts = ioread32(p + PCH_I2CSR);
631 	sts &= (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT);
632 	if (sts & I2CMAL_BIT)
633 		adap->pch_event_flag |= I2CMAL_EVENT;
634 
635 	if (sts & I2CMCF_BIT)
636 		adap->pch_event_flag |= I2CMCF_EVENT;
637 
638 	/* clear the applicable bits */
639 	pch_clrbit(adap->pch_base_address, PCH_I2CSR, sts);
640 
641 	pch_dbg(adap, "PCH_I2CSR = %x\n", ioread32(p + PCH_I2CSR));
642 
643 	wake_up(&pch_event);
644 }
645 
646 /**
647  * pch_i2c_handler() - interrupt handler for the PCH I2C controller
648  * @irq:	irq number.
649  * @pData:	cookie passed back to the handler function.
650  */
651 static irqreturn_t pch_i2c_handler(int irq, void *pData)
652 {
653 	u32 reg_val;
654 	int flag;
655 	int i;
656 	struct adapter_info *adap_info = pData;
657 	void __iomem *p;
658 	u32 mode;
659 
660 	for (i = 0, flag = 0; i < adap_info->ch_num; i++) {
661 		p = adap_info->pch_data[i].pch_base_address;
662 		mode = ioread32(p + PCH_I2CMOD);
663 		mode &= BUFFER_MODE | EEPROM_SR_MODE;
664 		if (mode != NORMAL_MODE) {
665 			pch_err(adap_info->pch_data,
666 				"I2C-%d mode(%d) is not supported\n", mode, i);
667 			continue;
668 		}
669 		reg_val = ioread32(p + PCH_I2CSR);
670 		if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT)) {
671 			pch_i2c_cb(&adap_info->pch_data[i]);
672 			flag = 1;
673 		}
674 	}
675 
676 	return flag ? IRQ_HANDLED : IRQ_NONE;
677 }
678 
679 /**
680  * pch_i2c_xfer() - Reading adnd writing data through I2C bus
681  * @i2c_adap:	Pointer to the struct i2c_adapter.
682  * @msgs:	Pointer to i2c_msg structure.
683  * @num:	number of messages.
684  */
685 static s32 pch_i2c_xfer(struct i2c_adapter *i2c_adap,
686 			struct i2c_msg *msgs, s32 num)
687 {
688 	struct i2c_msg *pmsg;
689 	u32 i = 0;
690 	u32 status;
691 	s32 ret;
692 
693 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
694 
695 	ret = mutex_lock_interruptible(&pch_mutex);
696 	if (ret)
697 		return ret;
698 
699 	if (adap->p_adapter_info->pch_i2c_suspended) {
700 		mutex_unlock(&pch_mutex);
701 		return -EBUSY;
702 	}
703 
704 	pch_dbg(adap, "adap->p_adapter_info->pch_i2c_suspended is %d\n",
705 		adap->p_adapter_info->pch_i2c_suspended);
706 	/* transfer not completed */
707 	adap->pch_i2c_xfer_in_progress = true;
708 
709 	for (i = 0; i < num && ret >= 0; i++) {
710 		pmsg = &msgs[i];
711 		pmsg->flags |= adap->pch_buff_mode_en;
712 		status = pmsg->flags;
713 		pch_dbg(adap,
714 			"After invoking I2C_MODE_SEL :flag= 0x%x\n", status);
715 
716 		if ((status & (I2C_M_RD)) != false) {
717 			ret = pch_i2c_readbytes(i2c_adap, pmsg, (i + 1 == num),
718 						(i == 0));
719 		} else {
720 			ret = pch_i2c_writebytes(i2c_adap, pmsg, (i + 1 == num),
721 						 (i == 0));
722 		}
723 	}
724 
725 	adap->pch_i2c_xfer_in_progress = false;	/* transfer completed */
726 
727 	mutex_unlock(&pch_mutex);
728 
729 	return (ret < 0) ? ret : num;
730 }
731 
732 /**
733  * pch_i2c_func() - return the functionality of the I2C driver
734  * @adap:	Pointer to struct i2c_algo_pch_data.
735  */
736 static u32 pch_i2c_func(struct i2c_adapter *adap)
737 {
738 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
739 }
740 
741 static struct i2c_algorithm pch_algorithm = {
742 	.master_xfer = pch_i2c_xfer,
743 	.functionality = pch_i2c_func
744 };
745 
746 /**
747  * pch_i2c_disbl_int() - Disable PCH I2C interrupts
748  * @adap:	Pointer to struct i2c_algo_pch_data.
749  */
750 static void pch_i2c_disbl_int(struct i2c_algo_pch_data *adap)
751 {
752 	void __iomem *p = adap->pch_base_address;
753 
754 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, NORMAL_INTR_ENBL);
755 
756 	iowrite32(EEPROM_RST_INTR_DISBL, p + PCH_I2CESRMSK);
757 
758 	iowrite32(BUFFER_MODE_INTR_DISBL, p + PCH_I2CBUFMSK);
759 }
760 
761 static int __devinit pch_i2c_probe(struct pci_dev *pdev,
762 				   const struct pci_device_id *id)
763 {
764 	void __iomem *base_addr;
765 	int ret;
766 	int i, j;
767 	struct adapter_info *adap_info;
768 	struct i2c_adapter *pch_adap;
769 
770 	pch_pci_dbg(pdev, "Entered.\n");
771 
772 	adap_info = kzalloc((sizeof(struct adapter_info)), GFP_KERNEL);
773 	if (adap_info == NULL) {
774 		pch_pci_err(pdev, "Memory allocation FAILED\n");
775 		return -ENOMEM;
776 	}
777 
778 	ret = pci_enable_device(pdev);
779 	if (ret) {
780 		pch_pci_err(pdev, "pci_enable_device FAILED\n");
781 		goto err_pci_enable;
782 	}
783 
784 	ret = pci_request_regions(pdev, KBUILD_MODNAME);
785 	if (ret) {
786 		pch_pci_err(pdev, "pci_request_regions FAILED\n");
787 		goto err_pci_req;
788 	}
789 
790 	base_addr = pci_iomap(pdev, 1, 0);
791 
792 	if (base_addr == NULL) {
793 		pch_pci_err(pdev, "pci_iomap FAILED\n");
794 		ret = -ENOMEM;
795 		goto err_pci_iomap;
796 	}
797 
798 	/* Set the number of I2C channel instance */
799 	adap_info->ch_num = id->driver_data;
800 
801 	ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED,
802 		  KBUILD_MODNAME, adap_info);
803 	if (ret) {
804 		pch_pci_err(pdev, "request_irq FAILED\n");
805 		goto err_request_irq;
806 	}
807 
808 	for (i = 0; i < adap_info->ch_num; i++) {
809 		pch_adap = &adap_info->pch_data[i].pch_adapter;
810 		adap_info->pch_i2c_suspended = false;
811 
812 		adap_info->pch_data[i].p_adapter_info = adap_info;
813 
814 		pch_adap->owner = THIS_MODULE;
815 		pch_adap->class = I2C_CLASS_HWMON;
816 		strlcpy(pch_adap->name, KBUILD_MODNAME, sizeof(pch_adap->name));
817 		pch_adap->algo = &pch_algorithm;
818 		pch_adap->algo_data = &adap_info->pch_data[i];
819 
820 		/* base_addr + offset; */
821 		adap_info->pch_data[i].pch_base_address = base_addr + 0x100 * i;
822 
823 		pch_adap->dev.parent = &pdev->dev;
824 
825 		pch_i2c_init(&adap_info->pch_data[i]);
826 
827 		pch_adap->nr = i;
828 		ret = i2c_add_numbered_adapter(pch_adap);
829 		if (ret) {
830 			pch_pci_err(pdev, "i2c_add_adapter[ch:%d] FAILED\n", i);
831 			goto err_add_adapter;
832 		}
833 	}
834 
835 	pci_set_drvdata(pdev, adap_info);
836 	pch_pci_dbg(pdev, "returns %d.\n", ret);
837 	return 0;
838 
839 err_add_adapter:
840 	for (j = 0; j < i; j++)
841 		i2c_del_adapter(&adap_info->pch_data[j].pch_adapter);
842 	free_irq(pdev->irq, adap_info);
843 err_request_irq:
844 	pci_iounmap(pdev, base_addr);
845 err_pci_iomap:
846 	pci_release_regions(pdev);
847 err_pci_req:
848 	pci_disable_device(pdev);
849 err_pci_enable:
850 	kfree(adap_info);
851 	return ret;
852 }
853 
854 static void __devexit pch_i2c_remove(struct pci_dev *pdev)
855 {
856 	int i;
857 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
858 
859 	free_irq(pdev->irq, adap_info);
860 
861 	for (i = 0; i < adap_info->ch_num; i++) {
862 		pch_i2c_disbl_int(&adap_info->pch_data[i]);
863 		i2c_del_adapter(&adap_info->pch_data[i].pch_adapter);
864 	}
865 
866 	if (adap_info->pch_data[0].pch_base_address)
867 		pci_iounmap(pdev, adap_info->pch_data[0].pch_base_address);
868 
869 	for (i = 0; i < adap_info->ch_num; i++)
870 		adap_info->pch_data[i].pch_base_address = NULL;
871 
872 	pci_set_drvdata(pdev, NULL);
873 
874 	pci_release_regions(pdev);
875 
876 	pci_disable_device(pdev);
877 	kfree(adap_info);
878 }
879 
880 #ifdef CONFIG_PM
881 static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
882 {
883 	int ret;
884 	int i;
885 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
886 	void __iomem *p = adap_info->pch_data[0].pch_base_address;
887 
888 	adap_info->pch_i2c_suspended = true;
889 
890 	for (i = 0; i < adap_info->ch_num; i++) {
891 		while ((adap_info->pch_data[i].pch_i2c_xfer_in_progress)) {
892 			/* Wait until all channel transfers are completed */
893 			msleep(20);
894 		}
895 	}
896 
897 	/* Disable the i2c interrupts */
898 	for (i = 0; i < adap_info->ch_num; i++)
899 		pch_i2c_disbl_int(&adap_info->pch_data[i]);
900 
901 	pch_pci_dbg(pdev, "I2CSR = %x I2CBUFSTA = %x I2CESRSTA = %x "
902 		"invoked function pch_i2c_disbl_int successfully\n",
903 		ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
904 		ioread32(p + PCH_I2CESRSTA));
905 
906 	ret = pci_save_state(pdev);
907 
908 	if (ret) {
909 		pch_pci_err(pdev, "pci_save_state\n");
910 		return ret;
911 	}
912 
913 	pci_enable_wake(pdev, PCI_D3hot, 0);
914 	pci_disable_device(pdev);
915 	pci_set_power_state(pdev, pci_choose_state(pdev, state));
916 
917 	return 0;
918 }
919 
920 static int pch_i2c_resume(struct pci_dev *pdev)
921 {
922 	int i;
923 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
924 
925 	pci_set_power_state(pdev, PCI_D0);
926 	pci_restore_state(pdev);
927 
928 	if (pci_enable_device(pdev) < 0) {
929 		pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
930 		return -EIO;
931 	}
932 
933 	pci_enable_wake(pdev, PCI_D3hot, 0);
934 
935 	for (i = 0; i < adap_info->ch_num; i++)
936 		pch_i2c_init(&adap_info->pch_data[i]);
937 
938 	adap_info->pch_i2c_suspended = false;
939 
940 	return 0;
941 }
942 #else
943 #define pch_i2c_suspend NULL
944 #define pch_i2c_resume NULL
945 #endif
946 
947 static struct pci_driver pch_pcidriver = {
948 	.name = KBUILD_MODNAME,
949 	.id_table = pch_pcidev_id,
950 	.probe = pch_i2c_probe,
951 	.remove = __devexit_p(pch_i2c_remove),
952 	.suspend = pch_i2c_suspend,
953 	.resume = pch_i2c_resume
954 };
955 
956 static int __init pch_pci_init(void)
957 {
958 	return pci_register_driver(&pch_pcidriver);
959 }
960 module_init(pch_pci_init);
961 
962 static void __exit pch_pci_exit(void)
963 {
964 	pci_unregister_driver(&pch_pcidriver);
965 }
966 module_exit(pch_pci_exit);
967 
968 MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semico ML7213/ML7223/ML7831 IOH I2C");
969 MODULE_LICENSE("GPL");
970 MODULE_AUTHOR("Tomoya MORINAGA. <tomoya.rohm@gmail.com>");
971 module_param(pch_i2c_speed, int, (S_IRUSR | S_IWUSR));
972 module_param(pch_clk, int, (S_IRUSR | S_IWUSR));
973