xref: /linux/drivers/i2c/busses/i2c-eg20t.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
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 static inline bool ktime_lt(const ktime_t cmp1, const ktime_t cmp2)
267 {
268 	return cmp1.tv64 < cmp2.tv64;
269 }
270 
271 /**
272  * pch_i2c_wait_for_bus_idle() - check the status of bus.
273  * @adap:	Pointer to struct i2c_algo_pch_data.
274  * @timeout:	waiting time counter (us).
275  */
276 static s32 pch_i2c_wait_for_bus_idle(struct i2c_algo_pch_data *adap,
277 				     s32 timeout)
278 {
279 	void __iomem *p = adap->pch_base_address;
280 	ktime_t ns_val;
281 
282 	if ((ioread32(p + PCH_I2CSR) & I2CMBB_BIT) == 0)
283 		return 0;
284 
285 	/* MAX timeout value is timeout*1000*1000nsec */
286 	ns_val = ktime_add_ns(ktime_get(), timeout*1000*1000);
287 	do {
288 		msleep(20);
289 		if ((ioread32(p + PCH_I2CSR) & I2CMBB_BIT) == 0)
290 			return 0;
291 	} while (ktime_lt(ktime_get(), ns_val));
292 
293 	pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
294 	pch_err(adap, "%s: Timeout Error.return%d\n", __func__, -ETIME);
295 	pch_i2c_init(adap);
296 
297 	return -ETIME;
298 }
299 
300 /**
301  * pch_i2c_start() - Generate I2C start condition in normal mode.
302  * @adap:	Pointer to struct i2c_algo_pch_data.
303  *
304  * Generate I2C start condition in normal mode by setting I2CCTL.I2CMSTA to 1.
305  */
306 static void pch_i2c_start(struct i2c_algo_pch_data *adap)
307 {
308 	void __iomem *p = adap->pch_base_address;
309 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
310 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
311 }
312 
313 /**
314  * pch_i2c_wait_for_xfer_complete() - initiates a wait for the tx complete event
315  * @adap:	Pointer to struct i2c_algo_pch_data.
316  */
317 static s32 pch_i2c_wait_for_xfer_complete(struct i2c_algo_pch_data *adap)
318 {
319 	long ret;
320 	ret = wait_event_timeout(pch_event,
321 			(adap->pch_event_flag != 0), msecs_to_jiffies(50));
322 
323 	if (ret == 0) {
324 		pch_err(adap, "timeout: %x\n", adap->pch_event_flag);
325 		adap->pch_event_flag = 0;
326 		return -ETIMEDOUT;
327 	}
328 
329 	if (adap->pch_event_flag & I2C_ERROR_MASK) {
330 		pch_err(adap, "error bits set: %x\n", adap->pch_event_flag);
331 		adap->pch_event_flag = 0;
332 		return -EIO;
333 	}
334 
335 	adap->pch_event_flag = 0;
336 
337 	return 0;
338 }
339 
340 /**
341  * pch_i2c_getack() - to confirm ACK/NACK
342  * @adap:	Pointer to struct i2c_algo_pch_data.
343  */
344 static s32 pch_i2c_getack(struct i2c_algo_pch_data *adap)
345 {
346 	u32 reg_val;
347 	void __iomem *p = adap->pch_base_address;
348 	reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
349 
350 	if (reg_val != 0) {
351 		pch_err(adap, "return%d\n", -EPROTO);
352 		return -EPROTO;
353 	}
354 
355 	return 0;
356 }
357 
358 /**
359  * pch_i2c_stop() - generate stop condition in normal mode.
360  * @adap:	Pointer to struct i2c_algo_pch_data.
361  */
362 static void pch_i2c_stop(struct i2c_algo_pch_data *adap)
363 {
364 	void __iomem *p = adap->pch_base_address;
365 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
366 	/* clear the start bit */
367 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
368 }
369 
370 /**
371  * pch_i2c_repstart() - generate repeated start condition in normal mode
372  * @adap:	Pointer to struct i2c_algo_pch_data.
373  */
374 static void pch_i2c_repstart(struct i2c_algo_pch_data *adap)
375 {
376 	void __iomem *p = adap->pch_base_address;
377 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
378 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_REPSTART);
379 }
380 
381 /**
382  * pch_i2c_writebytes() - write data to I2C bus in normal mode
383  * @i2c_adap:	Pointer to the struct i2c_adapter.
384  * @last:	specifies whether last message or not.
385  *		In the case of compound mode it will be 1 for last message,
386  *		otherwise 0.
387  * @first:	specifies whether first message or not.
388  *		1 for first message otherwise 0.
389  */
390 static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
391 			      struct i2c_msg *msgs, u32 last, u32 first)
392 {
393 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
394 	u8 *buf;
395 	u32 length;
396 	u32 addr;
397 	u32 addr_2_msb;
398 	u32 addr_8_lsb;
399 	s32 wrcount;
400 	s32 rtn;
401 	void __iomem *p = adap->pch_base_address;
402 
403 	length = msgs->len;
404 	buf = msgs->buf;
405 	addr = msgs->addr;
406 
407 	/* enable master tx */
408 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
409 
410 	pch_dbg(adap, "I2CCTL = %x msgs->len = %d\n", ioread32(p + PCH_I2CCTL),
411 		length);
412 
413 	if (first) {
414 		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
415 			return -ETIME;
416 	}
417 
418 	if (msgs->flags & I2C_M_TEN) {
419 		addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7) & 0x06;
420 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
421 		if (first)
422 			pch_i2c_start(adap);
423 
424 		rtn = pch_i2c_wait_for_xfer_complete(adap);
425 		if (rtn == 0) {
426 			if (pch_i2c_getack(adap)) {
427 				pch_dbg(adap, "Receive NACK for slave address"
428 					"setting\n");
429 				return -EIO;
430 			}
431 			addr_8_lsb = (addr & I2C_ADDR_MSK);
432 			iowrite32(addr_8_lsb, p + PCH_I2CDR);
433 		} else if (rtn == -EIO) { /* Arbitration Lost */
434 			pch_err(adap, "Lost Arbitration\n");
435 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
436 				   I2CMAL_BIT);
437 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
438 				   I2CMIF_BIT);
439 			pch_i2c_init(adap);
440 			return -EAGAIN;
441 		} else { /* wait-event timeout */
442 			pch_i2c_stop(adap);
443 			return -ETIME;
444 		}
445 	} else {
446 		/* set 7 bit slave address and R/W bit as 0 */
447 		iowrite32(addr << 1, p + PCH_I2CDR);
448 		if (first)
449 			pch_i2c_start(adap);
450 	}
451 
452 	rtn = pch_i2c_wait_for_xfer_complete(adap);
453 	if (rtn == 0) {
454 		if (pch_i2c_getack(adap)) {
455 			pch_dbg(adap, "Receive NACK for slave address"
456 				"setting\n");
457 			return -EIO;
458 		}
459 	} else if (rtn == -EIO) { /* Arbitration Lost */
460 		pch_err(adap, "Lost Arbitration\n");
461 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
462 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
463 		pch_i2c_init(adap);
464 		return -EAGAIN;
465 	} else { /* wait-event timeout */
466 		pch_i2c_stop(adap);
467 		return -ETIME;
468 	}
469 
470 	for (wrcount = 0; wrcount < length; ++wrcount) {
471 		/* write buffer value to I2C data register */
472 		iowrite32(buf[wrcount], p + PCH_I2CDR);
473 		pch_dbg(adap, "writing %x to Data register\n", buf[wrcount]);
474 
475 		rtn = pch_i2c_wait_for_xfer_complete(adap);
476 		if (rtn == 0) {
477 			if (pch_i2c_getack(adap)) {
478 				pch_dbg(adap, "Receive NACK for slave address"
479 					"setting\n");
480 				return -EIO;
481 			}
482 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
483 				   I2CMCF_BIT);
484 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
485 				   I2CMIF_BIT);
486 		} else { /* wait-event timeout */
487 			pch_i2c_stop(adap);
488 			return -ETIME;
489 		}
490 	}
491 
492 	/* check if this is the last message */
493 	if (last)
494 		pch_i2c_stop(adap);
495 	else
496 		pch_i2c_repstart(adap);
497 
498 	pch_dbg(adap, "return=%d\n", wrcount);
499 
500 	return wrcount;
501 }
502 
503 /**
504  * pch_i2c_sendack() - send ACK
505  * @adap:	Pointer to struct i2c_algo_pch_data.
506  */
507 static void pch_i2c_sendack(struct i2c_algo_pch_data *adap)
508 {
509 	void __iomem *p = adap->pch_base_address;
510 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
511 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
512 }
513 
514 /**
515  * pch_i2c_sendnack() - send NACK
516  * @adap:	Pointer to struct i2c_algo_pch_data.
517  */
518 static void pch_i2c_sendnack(struct i2c_algo_pch_data *adap)
519 {
520 	void __iomem *p = adap->pch_base_address;
521 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
522 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
523 }
524 
525 /**
526  * pch_i2c_restart() - Generate I2C restart condition in normal mode.
527  * @adap:	Pointer to struct i2c_algo_pch_data.
528  *
529  * Generate I2C restart condition in normal mode by setting I2CCTL.I2CRSTA.
530  */
531 static void pch_i2c_restart(struct i2c_algo_pch_data *adap)
532 {
533 	void __iomem *p = adap->pch_base_address;
534 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
535 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_RESTART);
536 }
537 
538 /**
539  * pch_i2c_readbytes() - read data  from I2C bus in normal mode.
540  * @i2c_adap:	Pointer to the struct i2c_adapter.
541  * @msgs:	Pointer to i2c_msg structure.
542  * @last:	specifies whether last message or not.
543  * @first:	specifies whether first message or not.
544  */
545 static s32 pch_i2c_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
546 			     u32 last, u32 first)
547 {
548 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
549 
550 	u8 *buf;
551 	u32 count;
552 	u32 length;
553 	u32 addr;
554 	u32 addr_2_msb;
555 	u32 addr_8_lsb;
556 	void __iomem *p = adap->pch_base_address;
557 	s32 rtn;
558 
559 	length = msgs->len;
560 	buf = msgs->buf;
561 	addr = msgs->addr;
562 
563 	/* enable master reception */
564 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
565 
566 	if (first) {
567 		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
568 			return -ETIME;
569 	}
570 
571 	if (msgs->flags & I2C_M_TEN) {
572 		addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7);
573 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
574 		if (first)
575 			pch_i2c_start(adap);
576 
577 		rtn = pch_i2c_wait_for_xfer_complete(adap);
578 		if (rtn == 0) {
579 			if (pch_i2c_getack(adap)) {
580 				pch_dbg(adap, "Receive NACK for slave address"
581 					"setting\n");
582 				return -EIO;
583 			}
584 			addr_8_lsb = (addr & I2C_ADDR_MSK);
585 			iowrite32(addr_8_lsb, p + PCH_I2CDR);
586 		} else if (rtn == -EIO) { /* Arbitration Lost */
587 			pch_err(adap, "Lost Arbitration\n");
588 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
589 				   I2CMAL_BIT);
590 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
591 				   I2CMIF_BIT);
592 			pch_i2c_init(adap);
593 			return -EAGAIN;
594 		} else { /* wait-event timeout */
595 			pch_i2c_stop(adap);
596 			return -ETIME;
597 		}
598 		pch_i2c_restart(adap);
599 		rtn = pch_i2c_wait_for_xfer_complete(adap);
600 		if (rtn == 0) {
601 			if (pch_i2c_getack(adap)) {
602 				pch_dbg(adap, "Receive NACK for slave address"
603 					"setting\n");
604 				return -EIO;
605 			}
606 			addr_2_msb |= I2C_RD;
607 			iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK,
608 				  p + PCH_I2CDR);
609 		} else if (rtn == -EIO) { /* Arbitration Lost */
610 			pch_err(adap, "Lost Arbitration\n");
611 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
612 				   I2CMAL_BIT);
613 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
614 				   I2CMIF_BIT);
615 			pch_i2c_init(adap);
616 			return -EAGAIN;
617 		} else { /* wait-event timeout */
618 			pch_i2c_stop(adap);
619 			return -ETIME;
620 		}
621 	} else {
622 		/* 7 address bits + R/W bit */
623 		addr = (((addr) << 1) | (I2C_RD));
624 		iowrite32(addr, p + PCH_I2CDR);
625 	}
626 
627 	/* check if it is the first message */
628 	if (first)
629 		pch_i2c_start(adap);
630 
631 	rtn = pch_i2c_wait_for_xfer_complete(adap);
632 	if (rtn == 0) {
633 		if (pch_i2c_getack(adap)) {
634 			pch_dbg(adap, "Receive NACK for slave address"
635 				"setting\n");
636 			return -EIO;
637 		}
638 	} else if (rtn == -EIO) { /* Arbitration Lost */
639 		pch_err(adap, "Lost Arbitration\n");
640 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
641 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
642 		pch_i2c_init(adap);
643 		return -EAGAIN;
644 	} else { /* wait-event timeout */
645 		pch_i2c_stop(adap);
646 		return -ETIME;
647 	}
648 
649 	if (length == 0) {
650 		pch_i2c_stop(adap);
651 		ioread32(p + PCH_I2CDR); /* Dummy read needs */
652 
653 		count = length;
654 	} else {
655 		int read_index;
656 		int loop;
657 		pch_i2c_sendack(adap);
658 
659 		/* Dummy read */
660 		for (loop = 1, read_index = 0; loop < length; loop++) {
661 			buf[read_index] = ioread32(p + PCH_I2CDR);
662 
663 			if (loop != 1)
664 				read_index++;
665 
666 			rtn = pch_i2c_wait_for_xfer_complete(adap);
667 			if (rtn == 0) {
668 				if (pch_i2c_getack(adap)) {
669 					pch_dbg(adap, "Receive NACK for slave"
670 						"address setting\n");
671 					return -EIO;
672 				}
673 			} else { /* wait-event timeout */
674 				pch_i2c_stop(adap);
675 				return -ETIME;
676 			}
677 
678 		}	/* end for */
679 
680 		pch_i2c_sendnack(adap);
681 
682 		buf[read_index] = ioread32(p + PCH_I2CDR); /* Read final - 1 */
683 
684 		if (length != 1)
685 			read_index++;
686 
687 		rtn = pch_i2c_wait_for_xfer_complete(adap);
688 		if (rtn == 0) {
689 			if (pch_i2c_getack(adap)) {
690 				pch_dbg(adap, "Receive NACK for slave"
691 					"address setting\n");
692 				return -EIO;
693 			}
694 		} else { /* wait-event timeout */
695 			pch_i2c_stop(adap);
696 			return -ETIME;
697 		}
698 
699 		if (last)
700 			pch_i2c_stop(adap);
701 		else
702 			pch_i2c_repstart(adap);
703 
704 		buf[read_index++] = ioread32(p + PCH_I2CDR); /* Read Final */
705 		count = read_index;
706 	}
707 
708 	return count;
709 }
710 
711 /**
712  * pch_i2c_cb() - Interrupt handler Call back function
713  * @adap:	Pointer to struct i2c_algo_pch_data.
714  */
715 static void pch_i2c_cb(struct i2c_algo_pch_data *adap)
716 {
717 	u32 sts;
718 	void __iomem *p = adap->pch_base_address;
719 
720 	sts = ioread32(p + PCH_I2CSR);
721 	sts &= (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT);
722 	if (sts & I2CMAL_BIT)
723 		adap->pch_event_flag |= I2CMAL_EVENT;
724 
725 	if (sts & I2CMCF_BIT)
726 		adap->pch_event_flag |= I2CMCF_EVENT;
727 
728 	/* clear the applicable bits */
729 	pch_clrbit(adap->pch_base_address, PCH_I2CSR, sts);
730 
731 	pch_dbg(adap, "PCH_I2CSR = %x\n", ioread32(p + PCH_I2CSR));
732 
733 	wake_up(&pch_event);
734 }
735 
736 /**
737  * pch_i2c_handler() - interrupt handler for the PCH I2C controller
738  * @irq:	irq number.
739  * @pData:	cookie passed back to the handler function.
740  */
741 static irqreturn_t pch_i2c_handler(int irq, void *pData)
742 {
743 	u32 reg_val;
744 	int flag;
745 	int i;
746 	struct adapter_info *adap_info = pData;
747 	void __iomem *p;
748 	u32 mode;
749 
750 	for (i = 0, flag = 0; i < adap_info->ch_num; i++) {
751 		p = adap_info->pch_data[i].pch_base_address;
752 		mode = ioread32(p + PCH_I2CMOD);
753 		mode &= BUFFER_MODE | EEPROM_SR_MODE;
754 		if (mode != NORMAL_MODE) {
755 			pch_err(adap_info->pch_data,
756 				"I2C-%d mode(%d) is not supported\n", mode, i);
757 			continue;
758 		}
759 		reg_val = ioread32(p + PCH_I2CSR);
760 		if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT)) {
761 			pch_i2c_cb(&adap_info->pch_data[i]);
762 			flag = 1;
763 		}
764 	}
765 
766 	return flag ? IRQ_HANDLED : IRQ_NONE;
767 }
768 
769 /**
770  * pch_i2c_xfer() - Reading adnd writing data through I2C bus
771  * @i2c_adap:	Pointer to the struct i2c_adapter.
772  * @msgs:	Pointer to i2c_msg structure.
773  * @num:	number of messages.
774  */
775 static s32 pch_i2c_xfer(struct i2c_adapter *i2c_adap,
776 			struct i2c_msg *msgs, s32 num)
777 {
778 	struct i2c_msg *pmsg;
779 	u32 i = 0;
780 	u32 status;
781 	u32 msglen;
782 	u32 subaddrlen;
783 	s32 ret;
784 
785 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
786 
787 	ret = mutex_lock_interruptible(&pch_mutex);
788 	if (ret)
789 		return -ERESTARTSYS;
790 
791 	if (adap->p_adapter_info->pch_i2c_suspended) {
792 		mutex_unlock(&pch_mutex);
793 		return -EBUSY;
794 	}
795 
796 	pch_dbg(adap, "adap->p_adapter_info->pch_i2c_suspended is %d\n",
797 		adap->p_adapter_info->pch_i2c_suspended);
798 	/* transfer not completed */
799 	adap->pch_i2c_xfer_in_progress = true;
800 
801 	for (i = 0; i < num && ret >= 0; i++) {
802 		pmsg = &msgs[i];
803 		pmsg->flags |= adap->pch_buff_mode_en;
804 		status = pmsg->flags;
805 		pch_dbg(adap,
806 			"After invoking I2C_MODE_SEL :flag= 0x%x\n", status);
807 		/* calculate sub address length and message length */
808 		/* these are applicable only for buffer mode */
809 		subaddrlen = pmsg->buf[0];
810 		/* calculate actual message length excluding
811 		 * the sub address fields */
812 		msglen = (pmsg->len) - (subaddrlen + 1);
813 
814 		if ((status & (I2C_M_RD)) != false) {
815 			ret = pch_i2c_readbytes(i2c_adap, pmsg, (i + 1 == num),
816 						(i == 0));
817 		} else {
818 			ret = pch_i2c_writebytes(i2c_adap, pmsg, (i + 1 == num),
819 						 (i == 0));
820 		}
821 	}
822 
823 	adap->pch_i2c_xfer_in_progress = false;	/* transfer completed */
824 
825 	mutex_unlock(&pch_mutex);
826 
827 	return (ret < 0) ? ret : num;
828 }
829 
830 /**
831  * pch_i2c_func() - return the functionality of the I2C driver
832  * @adap:	Pointer to struct i2c_algo_pch_data.
833  */
834 static u32 pch_i2c_func(struct i2c_adapter *adap)
835 {
836 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
837 }
838 
839 static struct i2c_algorithm pch_algorithm = {
840 	.master_xfer = pch_i2c_xfer,
841 	.functionality = pch_i2c_func
842 };
843 
844 /**
845  * pch_i2c_disbl_int() - Disable PCH I2C interrupts
846  * @adap:	Pointer to struct i2c_algo_pch_data.
847  */
848 static void pch_i2c_disbl_int(struct i2c_algo_pch_data *adap)
849 {
850 	void __iomem *p = adap->pch_base_address;
851 
852 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, NORMAL_INTR_ENBL);
853 
854 	iowrite32(EEPROM_RST_INTR_DISBL, p + PCH_I2CESRMSK);
855 
856 	iowrite32(BUFFER_MODE_INTR_DISBL, p + PCH_I2CBUFMSK);
857 }
858 
859 static int __devinit pch_i2c_probe(struct pci_dev *pdev,
860 				   const struct pci_device_id *id)
861 {
862 	void __iomem *base_addr;
863 	int ret;
864 	int i, j;
865 	struct adapter_info *adap_info;
866 	struct i2c_adapter *pch_adap;
867 
868 	pch_pci_dbg(pdev, "Entered.\n");
869 
870 	adap_info = kzalloc((sizeof(struct adapter_info)), GFP_KERNEL);
871 	if (adap_info == NULL) {
872 		pch_pci_err(pdev, "Memory allocation FAILED\n");
873 		return -ENOMEM;
874 	}
875 
876 	ret = pci_enable_device(pdev);
877 	if (ret) {
878 		pch_pci_err(pdev, "pci_enable_device FAILED\n");
879 		goto err_pci_enable;
880 	}
881 
882 	ret = pci_request_regions(pdev, KBUILD_MODNAME);
883 	if (ret) {
884 		pch_pci_err(pdev, "pci_request_regions FAILED\n");
885 		goto err_pci_req;
886 	}
887 
888 	base_addr = pci_iomap(pdev, 1, 0);
889 
890 	if (base_addr == NULL) {
891 		pch_pci_err(pdev, "pci_iomap FAILED\n");
892 		ret = -ENOMEM;
893 		goto err_pci_iomap;
894 	}
895 
896 	/* Set the number of I2C channel instance */
897 	adap_info->ch_num = id->driver_data;
898 
899 	ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED,
900 		  KBUILD_MODNAME, adap_info);
901 	if (ret) {
902 		pch_pci_err(pdev, "request_irq FAILED\n");
903 		goto err_request_irq;
904 	}
905 
906 	for (i = 0; i < adap_info->ch_num; i++) {
907 		pch_adap = &adap_info->pch_data[i].pch_adapter;
908 		adap_info->pch_i2c_suspended = false;
909 
910 		adap_info->pch_data[i].p_adapter_info = adap_info;
911 
912 		pch_adap->owner = THIS_MODULE;
913 		pch_adap->class = I2C_CLASS_HWMON;
914 		strcpy(pch_adap->name, KBUILD_MODNAME);
915 		pch_adap->algo = &pch_algorithm;
916 		pch_adap->algo_data = &adap_info->pch_data[i];
917 
918 		/* base_addr + offset; */
919 		adap_info->pch_data[i].pch_base_address = base_addr + 0x100 * i;
920 
921 		pch_adap->dev.parent = &pdev->dev;
922 
923 		pch_i2c_init(&adap_info->pch_data[i]);
924 
925 		pch_adap->nr = i;
926 		ret = i2c_add_numbered_adapter(pch_adap);
927 		if (ret) {
928 			pch_pci_err(pdev, "i2c_add_adapter[ch:%d] FAILED\n", i);
929 			goto err_add_adapter;
930 		}
931 	}
932 
933 	pci_set_drvdata(pdev, adap_info);
934 	pch_pci_dbg(pdev, "returns %d.\n", ret);
935 	return 0;
936 
937 err_add_adapter:
938 	for (j = 0; j < i; j++)
939 		i2c_del_adapter(&adap_info->pch_data[j].pch_adapter);
940 	free_irq(pdev->irq, adap_info);
941 err_request_irq:
942 	pci_iounmap(pdev, base_addr);
943 err_pci_iomap:
944 	pci_release_regions(pdev);
945 err_pci_req:
946 	pci_disable_device(pdev);
947 err_pci_enable:
948 	kfree(adap_info);
949 	return ret;
950 }
951 
952 static void __devexit pch_i2c_remove(struct pci_dev *pdev)
953 {
954 	int i;
955 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
956 
957 	free_irq(pdev->irq, adap_info);
958 
959 	for (i = 0; i < adap_info->ch_num; i++) {
960 		pch_i2c_disbl_int(&adap_info->pch_data[i]);
961 		i2c_del_adapter(&adap_info->pch_data[i].pch_adapter);
962 	}
963 
964 	if (adap_info->pch_data[0].pch_base_address)
965 		pci_iounmap(pdev, adap_info->pch_data[0].pch_base_address);
966 
967 	for (i = 0; i < adap_info->ch_num; i++)
968 		adap_info->pch_data[i].pch_base_address = 0;
969 
970 	pci_set_drvdata(pdev, NULL);
971 
972 	pci_release_regions(pdev);
973 
974 	pci_disable_device(pdev);
975 	kfree(adap_info);
976 }
977 
978 #ifdef CONFIG_PM
979 static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
980 {
981 	int ret;
982 	int i;
983 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
984 	void __iomem *p = adap_info->pch_data[0].pch_base_address;
985 
986 	adap_info->pch_i2c_suspended = true;
987 
988 	for (i = 0; i < adap_info->ch_num; i++) {
989 		while ((adap_info->pch_data[i].pch_i2c_xfer_in_progress)) {
990 			/* Wait until all channel transfers are completed */
991 			msleep(20);
992 		}
993 	}
994 
995 	/* Disable the i2c interrupts */
996 	for (i = 0; i < adap_info->ch_num; i++)
997 		pch_i2c_disbl_int(&adap_info->pch_data[i]);
998 
999 	pch_pci_dbg(pdev, "I2CSR = %x I2CBUFSTA = %x I2CESRSTA = %x "
1000 		"invoked function pch_i2c_disbl_int successfully\n",
1001 		ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
1002 		ioread32(p + PCH_I2CESRSTA));
1003 
1004 	ret = pci_save_state(pdev);
1005 
1006 	if (ret) {
1007 		pch_pci_err(pdev, "pci_save_state\n");
1008 		return ret;
1009 	}
1010 
1011 	pci_enable_wake(pdev, PCI_D3hot, 0);
1012 	pci_disable_device(pdev);
1013 	pci_set_power_state(pdev, pci_choose_state(pdev, state));
1014 
1015 	return 0;
1016 }
1017 
1018 static int pch_i2c_resume(struct pci_dev *pdev)
1019 {
1020 	int i;
1021 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
1022 
1023 	pci_set_power_state(pdev, PCI_D0);
1024 	pci_restore_state(pdev);
1025 
1026 	if (pci_enable_device(pdev) < 0) {
1027 		pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
1028 		return -EIO;
1029 	}
1030 
1031 	pci_enable_wake(pdev, PCI_D3hot, 0);
1032 
1033 	for (i = 0; i < adap_info->ch_num; i++)
1034 		pch_i2c_init(&adap_info->pch_data[i]);
1035 
1036 	adap_info->pch_i2c_suspended = false;
1037 
1038 	return 0;
1039 }
1040 #else
1041 #define pch_i2c_suspend NULL
1042 #define pch_i2c_resume NULL
1043 #endif
1044 
1045 static struct pci_driver pch_pcidriver = {
1046 	.name = KBUILD_MODNAME,
1047 	.id_table = pch_pcidev_id,
1048 	.probe = pch_i2c_probe,
1049 	.remove = __devexit_p(pch_i2c_remove),
1050 	.suspend = pch_i2c_suspend,
1051 	.resume = pch_i2c_resume
1052 };
1053 
1054 static int __init pch_pci_init(void)
1055 {
1056 	return pci_register_driver(&pch_pcidriver);
1057 }
1058 module_init(pch_pci_init);
1059 
1060 static void __exit pch_pci_exit(void)
1061 {
1062 	pci_unregister_driver(&pch_pcidriver);
1063 }
1064 module_exit(pch_pci_exit);
1065 
1066 MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semico ML7213/ML7223/ML7831 IOH I2C");
1067 MODULE_LICENSE("GPL");
1068 MODULE_AUTHOR("Tomoya MORINAGA. <tomoya-linux@dsn.lapis-semi.com>");
1069 module_param(pch_i2c_speed, int, (S_IRUSR | S_IWUSR));
1070 module_param(pch_clk, int, (S_IRUSR | S_IWUSR));
1071