xref: /openbmc/linux/drivers/i2c/busses/i2c-eg20t.c (revision ce932d0c5589e9766e089c22c66890dfc48fbd94)
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 (ms).
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 	int schedule = 0;
281 	unsigned long end = jiffies + msecs_to_jiffies(timeout);
282 
283 	while (ioread32(p + PCH_I2CSR) & I2CMBB_BIT) {
284 		if (time_after(jiffies, end)) {
285 			pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
286 			pch_err(adap, "%s: Timeout Error.return%d\n",
287 					__func__, -ETIME);
288 			pch_i2c_init(adap);
289 
290 			return -ETIME;
291 		}
292 
293 		if (!schedule)
294 			/* Retry after some usecs */
295 			udelay(5);
296 		else
297 			/* Wait a bit more without consuming CPU */
298 			usleep_range(20, 1000);
299 
300 		schedule = 1;
301 	}
302 
303 	return 0;
304 }
305 
306 /**
307  * pch_i2c_start() - Generate I2C start condition in normal mode.
308  * @adap:	Pointer to struct i2c_algo_pch_data.
309  *
310  * Generate I2C start condition in normal mode by setting I2CCTL.I2CMSTA to 1.
311  */
312 static void pch_i2c_start(struct i2c_algo_pch_data *adap)
313 {
314 	void __iomem *p = adap->pch_base_address;
315 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
316 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
317 }
318 
319 /**
320  * pch_i2c_wait_for_xfer_complete() - initiates a wait for the tx complete event
321  * @adap:	Pointer to struct i2c_algo_pch_data.
322  */
323 static s32 pch_i2c_wait_for_xfer_complete(struct i2c_algo_pch_data *adap)
324 {
325 	long ret;
326 	ret = wait_event_timeout(pch_event,
327 			(adap->pch_event_flag != 0), msecs_to_jiffies(1000));
328 
329 	if (ret == 0) {
330 		pch_err(adap, "timeout: %x\n", adap->pch_event_flag);
331 		adap->pch_event_flag = 0;
332 		return -ETIMEDOUT;
333 	}
334 
335 	if (adap->pch_event_flag & I2C_ERROR_MASK) {
336 		pch_err(adap, "error bits set: %x\n", adap->pch_event_flag);
337 		adap->pch_event_flag = 0;
338 		return -EIO;
339 	}
340 
341 	adap->pch_event_flag = 0;
342 
343 	return 0;
344 }
345 
346 /**
347  * pch_i2c_getack() - to confirm ACK/NACK
348  * @adap:	Pointer to struct i2c_algo_pch_data.
349  */
350 static s32 pch_i2c_getack(struct i2c_algo_pch_data *adap)
351 {
352 	u32 reg_val;
353 	void __iomem *p = adap->pch_base_address;
354 	reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
355 
356 	if (reg_val != 0) {
357 		pch_err(adap, "return%d\n", -EPROTO);
358 		return -EPROTO;
359 	}
360 
361 	return 0;
362 }
363 
364 /**
365  * pch_i2c_stop() - generate stop condition in normal mode.
366  * @adap:	Pointer to struct i2c_algo_pch_data.
367  */
368 static void pch_i2c_stop(struct i2c_algo_pch_data *adap)
369 {
370 	void __iomem *p = adap->pch_base_address;
371 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
372 	/* clear the start bit */
373 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
374 }
375 
376 /**
377  * pch_i2c_repstart() - generate repeated start condition in normal mode
378  * @adap:	Pointer to struct i2c_algo_pch_data.
379  */
380 static void pch_i2c_repstart(struct i2c_algo_pch_data *adap)
381 {
382 	void __iomem *p = adap->pch_base_address;
383 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
384 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_REPSTART);
385 }
386 
387 /**
388  * pch_i2c_writebytes() - write data to I2C bus in normal mode
389  * @i2c_adap:	Pointer to the struct i2c_adapter.
390  * @last:	specifies whether last message or not.
391  *		In the case of compound mode it will be 1 for last message,
392  *		otherwise 0.
393  * @first:	specifies whether first message or not.
394  *		1 for first message otherwise 0.
395  */
396 static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
397 			      struct i2c_msg *msgs, u32 last, u32 first)
398 {
399 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
400 	u8 *buf;
401 	u32 length;
402 	u32 addr;
403 	u32 addr_2_msb;
404 	u32 addr_8_lsb;
405 	s32 wrcount;
406 	s32 rtn;
407 	void __iomem *p = adap->pch_base_address;
408 
409 	length = msgs->len;
410 	buf = msgs->buf;
411 	addr = msgs->addr;
412 
413 	/* enable master tx */
414 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
415 
416 	pch_dbg(adap, "I2CCTL = %x msgs->len = %d\n", ioread32(p + PCH_I2CCTL),
417 		length);
418 
419 	if (first) {
420 		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
421 			return -ETIME;
422 	}
423 
424 	if (msgs->flags & I2C_M_TEN) {
425 		addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7) & 0x06;
426 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
427 		if (first)
428 			pch_i2c_start(adap);
429 
430 		rtn = pch_i2c_wait_for_xfer_complete(adap);
431 		if (rtn == 0) {
432 			if (pch_i2c_getack(adap)) {
433 				pch_dbg(adap, "Receive NACK for slave address"
434 					"setting\n");
435 				return -EIO;
436 			}
437 			addr_8_lsb = (addr & I2C_ADDR_MSK);
438 			iowrite32(addr_8_lsb, p + PCH_I2CDR);
439 		} else if (rtn == -EIO) { /* Arbitration Lost */
440 			pch_err(adap, "Lost Arbitration\n");
441 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
442 				   I2CMAL_BIT);
443 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
444 				   I2CMIF_BIT);
445 			pch_i2c_init(adap);
446 			return -EAGAIN;
447 		} else { /* wait-event timeout */
448 			pch_i2c_stop(adap);
449 			return -ETIME;
450 		}
451 	} else {
452 		/* set 7 bit slave address and R/W bit as 0 */
453 		iowrite32(addr << 1, p + PCH_I2CDR);
454 		if (first)
455 			pch_i2c_start(adap);
456 	}
457 
458 	rtn = pch_i2c_wait_for_xfer_complete(adap);
459 	if (rtn == 0) {
460 		if (pch_i2c_getack(adap)) {
461 			pch_dbg(adap, "Receive NACK for slave address"
462 				"setting\n");
463 			return -EIO;
464 		}
465 	} else if (rtn == -EIO) { /* Arbitration Lost */
466 		pch_err(adap, "Lost Arbitration\n");
467 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
468 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
469 		pch_i2c_init(adap);
470 		return -EAGAIN;
471 	} else { /* wait-event timeout */
472 		pch_i2c_stop(adap);
473 		return -ETIME;
474 	}
475 
476 	for (wrcount = 0; wrcount < length; ++wrcount) {
477 		/* write buffer value to I2C data register */
478 		iowrite32(buf[wrcount], p + PCH_I2CDR);
479 		pch_dbg(adap, "writing %x to Data register\n", buf[wrcount]);
480 
481 		rtn = pch_i2c_wait_for_xfer_complete(adap);
482 		if (rtn == 0) {
483 			if (pch_i2c_getack(adap)) {
484 				pch_dbg(adap, "Receive NACK for slave address"
485 					"setting\n");
486 				return -EIO;
487 			}
488 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
489 				   I2CMCF_BIT);
490 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
491 				   I2CMIF_BIT);
492 		} else { /* wait-event timeout */
493 			pch_i2c_stop(adap);
494 			return -ETIME;
495 		}
496 	}
497 
498 	/* check if this is the last message */
499 	if (last)
500 		pch_i2c_stop(adap);
501 	else
502 		pch_i2c_repstart(adap);
503 
504 	pch_dbg(adap, "return=%d\n", wrcount);
505 
506 	return wrcount;
507 }
508 
509 /**
510  * pch_i2c_sendack() - send ACK
511  * @adap:	Pointer to struct i2c_algo_pch_data.
512  */
513 static void pch_i2c_sendack(struct i2c_algo_pch_data *adap)
514 {
515 	void __iomem *p = adap->pch_base_address;
516 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
517 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
518 }
519 
520 /**
521  * pch_i2c_sendnack() - send NACK
522  * @adap:	Pointer to struct i2c_algo_pch_data.
523  */
524 static void pch_i2c_sendnack(struct i2c_algo_pch_data *adap)
525 {
526 	void __iomem *p = adap->pch_base_address;
527 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
528 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
529 }
530 
531 /**
532  * pch_i2c_restart() - Generate I2C restart condition in normal mode.
533  * @adap:	Pointer to struct i2c_algo_pch_data.
534  *
535  * Generate I2C restart condition in normal mode by setting I2CCTL.I2CRSTA.
536  */
537 static void pch_i2c_restart(struct i2c_algo_pch_data *adap)
538 {
539 	void __iomem *p = adap->pch_base_address;
540 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
541 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_RESTART);
542 }
543 
544 /**
545  * pch_i2c_readbytes() - read data  from I2C bus in normal mode.
546  * @i2c_adap:	Pointer to the struct i2c_adapter.
547  * @msgs:	Pointer to i2c_msg structure.
548  * @last:	specifies whether last message or not.
549  * @first:	specifies whether first message or not.
550  */
551 static s32 pch_i2c_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
552 			     u32 last, u32 first)
553 {
554 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
555 
556 	u8 *buf;
557 	u32 count;
558 	u32 length;
559 	u32 addr;
560 	u32 addr_2_msb;
561 	u32 addr_8_lsb;
562 	void __iomem *p = adap->pch_base_address;
563 	s32 rtn;
564 
565 	length = msgs->len;
566 	buf = msgs->buf;
567 	addr = msgs->addr;
568 
569 	/* enable master reception */
570 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
571 
572 	if (first) {
573 		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
574 			return -ETIME;
575 	}
576 
577 	if (msgs->flags & I2C_M_TEN) {
578 		addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7);
579 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
580 		if (first)
581 			pch_i2c_start(adap);
582 
583 		rtn = pch_i2c_wait_for_xfer_complete(adap);
584 		if (rtn == 0) {
585 			if (pch_i2c_getack(adap)) {
586 				pch_dbg(adap, "Receive NACK for slave address"
587 					"setting\n");
588 				return -EIO;
589 			}
590 			addr_8_lsb = (addr & I2C_ADDR_MSK);
591 			iowrite32(addr_8_lsb, p + PCH_I2CDR);
592 		} else if (rtn == -EIO) { /* Arbitration Lost */
593 			pch_err(adap, "Lost Arbitration\n");
594 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
595 				   I2CMAL_BIT);
596 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
597 				   I2CMIF_BIT);
598 			pch_i2c_init(adap);
599 			return -EAGAIN;
600 		} else { /* wait-event timeout */
601 			pch_i2c_stop(adap);
602 			return -ETIME;
603 		}
604 		pch_i2c_restart(adap);
605 		rtn = pch_i2c_wait_for_xfer_complete(adap);
606 		if (rtn == 0) {
607 			if (pch_i2c_getack(adap)) {
608 				pch_dbg(adap, "Receive NACK for slave address"
609 					"setting\n");
610 				return -EIO;
611 			}
612 			addr_2_msb |= I2C_RD;
613 			iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK,
614 				  p + PCH_I2CDR);
615 		} else if (rtn == -EIO) { /* Arbitration Lost */
616 			pch_err(adap, "Lost Arbitration\n");
617 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
618 				   I2CMAL_BIT);
619 			pch_clrbit(adap->pch_base_address, PCH_I2CSR,
620 				   I2CMIF_BIT);
621 			pch_i2c_init(adap);
622 			return -EAGAIN;
623 		} else { /* wait-event timeout */
624 			pch_i2c_stop(adap);
625 			return -ETIME;
626 		}
627 	} else {
628 		/* 7 address bits + R/W bit */
629 		addr = (((addr) << 1) | (I2C_RD));
630 		iowrite32(addr, p + PCH_I2CDR);
631 	}
632 
633 	/* check if it is the first message */
634 	if (first)
635 		pch_i2c_start(adap);
636 
637 	rtn = pch_i2c_wait_for_xfer_complete(adap);
638 	if (rtn == 0) {
639 		if (pch_i2c_getack(adap)) {
640 			pch_dbg(adap, "Receive NACK for slave address"
641 				"setting\n");
642 			return -EIO;
643 		}
644 	} else if (rtn == -EIO) { /* Arbitration Lost */
645 		pch_err(adap, "Lost Arbitration\n");
646 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
647 		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
648 		pch_i2c_init(adap);
649 		return -EAGAIN;
650 	} else { /* wait-event timeout */
651 		pch_i2c_stop(adap);
652 		return -ETIME;
653 	}
654 
655 	if (length == 0) {
656 		pch_i2c_stop(adap);
657 		ioread32(p + PCH_I2CDR); /* Dummy read needs */
658 
659 		count = length;
660 	} else {
661 		int read_index;
662 		int loop;
663 		pch_i2c_sendack(adap);
664 
665 		/* Dummy read */
666 		for (loop = 1, read_index = 0; loop < length; loop++) {
667 			buf[read_index] = ioread32(p + PCH_I2CDR);
668 
669 			if (loop != 1)
670 				read_index++;
671 
672 			rtn = pch_i2c_wait_for_xfer_complete(adap);
673 			if (rtn == 0) {
674 				if (pch_i2c_getack(adap)) {
675 					pch_dbg(adap, "Receive NACK for slave"
676 						"address setting\n");
677 					return -EIO;
678 				}
679 			} else { /* wait-event timeout */
680 				pch_i2c_stop(adap);
681 				return -ETIME;
682 			}
683 
684 		}	/* end for */
685 
686 		pch_i2c_sendnack(adap);
687 
688 		buf[read_index] = ioread32(p + PCH_I2CDR); /* Read final - 1 */
689 
690 		if (length != 1)
691 			read_index++;
692 
693 		rtn = pch_i2c_wait_for_xfer_complete(adap);
694 		if (rtn == 0) {
695 			if (pch_i2c_getack(adap)) {
696 				pch_dbg(adap, "Receive NACK for slave"
697 					"address setting\n");
698 				return -EIO;
699 			}
700 		} else { /* wait-event timeout */
701 			pch_i2c_stop(adap);
702 			return -ETIME;
703 		}
704 
705 		if (last)
706 			pch_i2c_stop(adap);
707 		else
708 			pch_i2c_repstart(adap);
709 
710 		buf[read_index++] = ioread32(p + PCH_I2CDR); /* Read Final */
711 		count = read_index;
712 	}
713 
714 	return count;
715 }
716 
717 /**
718  * pch_i2c_cb() - Interrupt handler Call back function
719  * @adap:	Pointer to struct i2c_algo_pch_data.
720  */
721 static void pch_i2c_cb(struct i2c_algo_pch_data *adap)
722 {
723 	u32 sts;
724 	void __iomem *p = adap->pch_base_address;
725 
726 	sts = ioread32(p + PCH_I2CSR);
727 	sts &= (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT);
728 	if (sts & I2CMAL_BIT)
729 		adap->pch_event_flag |= I2CMAL_EVENT;
730 
731 	if (sts & I2CMCF_BIT)
732 		adap->pch_event_flag |= I2CMCF_EVENT;
733 
734 	/* clear the applicable bits */
735 	pch_clrbit(adap->pch_base_address, PCH_I2CSR, sts);
736 
737 	pch_dbg(adap, "PCH_I2CSR = %x\n", ioread32(p + PCH_I2CSR));
738 
739 	wake_up(&pch_event);
740 }
741 
742 /**
743  * pch_i2c_handler() - interrupt handler for the PCH I2C controller
744  * @irq:	irq number.
745  * @pData:	cookie passed back to the handler function.
746  */
747 static irqreturn_t pch_i2c_handler(int irq, void *pData)
748 {
749 	u32 reg_val;
750 	int flag;
751 	int i;
752 	struct adapter_info *adap_info = pData;
753 	void __iomem *p;
754 	u32 mode;
755 
756 	for (i = 0, flag = 0; i < adap_info->ch_num; i++) {
757 		p = adap_info->pch_data[i].pch_base_address;
758 		mode = ioread32(p + PCH_I2CMOD);
759 		mode &= BUFFER_MODE | EEPROM_SR_MODE;
760 		if (mode != NORMAL_MODE) {
761 			pch_err(adap_info->pch_data,
762 				"I2C-%d mode(%d) is not supported\n", mode, i);
763 			continue;
764 		}
765 		reg_val = ioread32(p + PCH_I2CSR);
766 		if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT)) {
767 			pch_i2c_cb(&adap_info->pch_data[i]);
768 			flag = 1;
769 		}
770 	}
771 
772 	return flag ? IRQ_HANDLED : IRQ_NONE;
773 }
774 
775 /**
776  * pch_i2c_xfer() - Reading adnd writing data through I2C bus
777  * @i2c_adap:	Pointer to the struct i2c_adapter.
778  * @msgs:	Pointer to i2c_msg structure.
779  * @num:	number of messages.
780  */
781 static s32 pch_i2c_xfer(struct i2c_adapter *i2c_adap,
782 			struct i2c_msg *msgs, s32 num)
783 {
784 	struct i2c_msg *pmsg;
785 	u32 i = 0;
786 	u32 status;
787 	s32 ret;
788 
789 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
790 
791 	ret = mutex_lock_interruptible(&pch_mutex);
792 	if (ret)
793 		return -ERESTARTSYS;
794 
795 	if (adap->p_adapter_info->pch_i2c_suspended) {
796 		mutex_unlock(&pch_mutex);
797 		return -EBUSY;
798 	}
799 
800 	pch_dbg(adap, "adap->p_adapter_info->pch_i2c_suspended is %d\n",
801 		adap->p_adapter_info->pch_i2c_suspended);
802 	/* transfer not completed */
803 	adap->pch_i2c_xfer_in_progress = true;
804 
805 	for (i = 0; i < num && ret >= 0; i++) {
806 		pmsg = &msgs[i];
807 		pmsg->flags |= adap->pch_buff_mode_en;
808 		status = pmsg->flags;
809 		pch_dbg(adap,
810 			"After invoking I2C_MODE_SEL :flag= 0x%x\n", status);
811 
812 		if ((status & (I2C_M_RD)) != false) {
813 			ret = pch_i2c_readbytes(i2c_adap, pmsg, (i + 1 == num),
814 						(i == 0));
815 		} else {
816 			ret = pch_i2c_writebytes(i2c_adap, pmsg, (i + 1 == num),
817 						 (i == 0));
818 		}
819 	}
820 
821 	adap->pch_i2c_xfer_in_progress = false;	/* transfer completed */
822 
823 	mutex_unlock(&pch_mutex);
824 
825 	return (ret < 0) ? ret : num;
826 }
827 
828 /**
829  * pch_i2c_func() - return the functionality of the I2C driver
830  * @adap:	Pointer to struct i2c_algo_pch_data.
831  */
832 static u32 pch_i2c_func(struct i2c_adapter *adap)
833 {
834 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
835 }
836 
837 static struct i2c_algorithm pch_algorithm = {
838 	.master_xfer = pch_i2c_xfer,
839 	.functionality = pch_i2c_func
840 };
841 
842 /**
843  * pch_i2c_disbl_int() - Disable PCH I2C interrupts
844  * @adap:	Pointer to struct i2c_algo_pch_data.
845  */
846 static void pch_i2c_disbl_int(struct i2c_algo_pch_data *adap)
847 {
848 	void __iomem *p = adap->pch_base_address;
849 
850 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, NORMAL_INTR_ENBL);
851 
852 	iowrite32(EEPROM_RST_INTR_DISBL, p + PCH_I2CESRMSK);
853 
854 	iowrite32(BUFFER_MODE_INTR_DISBL, p + PCH_I2CBUFMSK);
855 }
856 
857 static int __devinit pch_i2c_probe(struct pci_dev *pdev,
858 				   const struct pci_device_id *id)
859 {
860 	void __iomem *base_addr;
861 	int ret;
862 	int i, j;
863 	struct adapter_info *adap_info;
864 	struct i2c_adapter *pch_adap;
865 
866 	pch_pci_dbg(pdev, "Entered.\n");
867 
868 	adap_info = kzalloc((sizeof(struct adapter_info)), GFP_KERNEL);
869 	if (adap_info == NULL) {
870 		pch_pci_err(pdev, "Memory allocation FAILED\n");
871 		return -ENOMEM;
872 	}
873 
874 	ret = pci_enable_device(pdev);
875 	if (ret) {
876 		pch_pci_err(pdev, "pci_enable_device FAILED\n");
877 		goto err_pci_enable;
878 	}
879 
880 	ret = pci_request_regions(pdev, KBUILD_MODNAME);
881 	if (ret) {
882 		pch_pci_err(pdev, "pci_request_regions FAILED\n");
883 		goto err_pci_req;
884 	}
885 
886 	base_addr = pci_iomap(pdev, 1, 0);
887 
888 	if (base_addr == NULL) {
889 		pch_pci_err(pdev, "pci_iomap FAILED\n");
890 		ret = -ENOMEM;
891 		goto err_pci_iomap;
892 	}
893 
894 	/* Set the number of I2C channel instance */
895 	adap_info->ch_num = id->driver_data;
896 
897 	ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED,
898 		  KBUILD_MODNAME, adap_info);
899 	if (ret) {
900 		pch_pci_err(pdev, "request_irq FAILED\n");
901 		goto err_request_irq;
902 	}
903 
904 	for (i = 0; i < adap_info->ch_num; i++) {
905 		pch_adap = &adap_info->pch_data[i].pch_adapter;
906 		adap_info->pch_i2c_suspended = false;
907 
908 		adap_info->pch_data[i].p_adapter_info = adap_info;
909 
910 		pch_adap->owner = THIS_MODULE;
911 		pch_adap->class = I2C_CLASS_HWMON;
912 		strcpy(pch_adap->name, KBUILD_MODNAME);
913 		pch_adap->algo = &pch_algorithm;
914 		pch_adap->algo_data = &adap_info->pch_data[i];
915 
916 		/* base_addr + offset; */
917 		adap_info->pch_data[i].pch_base_address = base_addr + 0x100 * i;
918 
919 		pch_adap->dev.parent = &pdev->dev;
920 
921 		pch_i2c_init(&adap_info->pch_data[i]);
922 
923 		pch_adap->nr = i;
924 		ret = i2c_add_numbered_adapter(pch_adap);
925 		if (ret) {
926 			pch_pci_err(pdev, "i2c_add_adapter[ch:%d] FAILED\n", i);
927 			goto err_add_adapter;
928 		}
929 	}
930 
931 	pci_set_drvdata(pdev, adap_info);
932 	pch_pci_dbg(pdev, "returns %d.\n", ret);
933 	return 0;
934 
935 err_add_adapter:
936 	for (j = 0; j < i; j++)
937 		i2c_del_adapter(&adap_info->pch_data[j].pch_adapter);
938 	free_irq(pdev->irq, adap_info);
939 err_request_irq:
940 	pci_iounmap(pdev, base_addr);
941 err_pci_iomap:
942 	pci_release_regions(pdev);
943 err_pci_req:
944 	pci_disable_device(pdev);
945 err_pci_enable:
946 	kfree(adap_info);
947 	return ret;
948 }
949 
950 static void __devexit pch_i2c_remove(struct pci_dev *pdev)
951 {
952 	int i;
953 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
954 
955 	free_irq(pdev->irq, adap_info);
956 
957 	for (i = 0; i < adap_info->ch_num; i++) {
958 		pch_i2c_disbl_int(&adap_info->pch_data[i]);
959 		i2c_del_adapter(&adap_info->pch_data[i].pch_adapter);
960 	}
961 
962 	if (adap_info->pch_data[0].pch_base_address)
963 		pci_iounmap(pdev, adap_info->pch_data[0].pch_base_address);
964 
965 	for (i = 0; i < adap_info->ch_num; i++)
966 		adap_info->pch_data[i].pch_base_address = 0;
967 
968 	pci_set_drvdata(pdev, NULL);
969 
970 	pci_release_regions(pdev);
971 
972 	pci_disable_device(pdev);
973 	kfree(adap_info);
974 }
975 
976 #ifdef CONFIG_PM
977 static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
978 {
979 	int ret;
980 	int i;
981 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
982 	void __iomem *p = adap_info->pch_data[0].pch_base_address;
983 
984 	adap_info->pch_i2c_suspended = true;
985 
986 	for (i = 0; i < adap_info->ch_num; i++) {
987 		while ((adap_info->pch_data[i].pch_i2c_xfer_in_progress)) {
988 			/* Wait until all channel transfers are completed */
989 			msleep(20);
990 		}
991 	}
992 
993 	/* Disable the i2c interrupts */
994 	for (i = 0; i < adap_info->ch_num; i++)
995 		pch_i2c_disbl_int(&adap_info->pch_data[i]);
996 
997 	pch_pci_dbg(pdev, "I2CSR = %x I2CBUFSTA = %x I2CESRSTA = %x "
998 		"invoked function pch_i2c_disbl_int successfully\n",
999 		ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
1000 		ioread32(p + PCH_I2CESRSTA));
1001 
1002 	ret = pci_save_state(pdev);
1003 
1004 	if (ret) {
1005 		pch_pci_err(pdev, "pci_save_state\n");
1006 		return ret;
1007 	}
1008 
1009 	pci_enable_wake(pdev, PCI_D3hot, 0);
1010 	pci_disable_device(pdev);
1011 	pci_set_power_state(pdev, pci_choose_state(pdev, state));
1012 
1013 	return 0;
1014 }
1015 
1016 static int pch_i2c_resume(struct pci_dev *pdev)
1017 {
1018 	int i;
1019 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
1020 
1021 	pci_set_power_state(pdev, PCI_D0);
1022 	pci_restore_state(pdev);
1023 
1024 	if (pci_enable_device(pdev) < 0) {
1025 		pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
1026 		return -EIO;
1027 	}
1028 
1029 	pci_enable_wake(pdev, PCI_D3hot, 0);
1030 
1031 	for (i = 0; i < adap_info->ch_num; i++)
1032 		pch_i2c_init(&adap_info->pch_data[i]);
1033 
1034 	adap_info->pch_i2c_suspended = false;
1035 
1036 	return 0;
1037 }
1038 #else
1039 #define pch_i2c_suspend NULL
1040 #define pch_i2c_resume NULL
1041 #endif
1042 
1043 static struct pci_driver pch_pcidriver = {
1044 	.name = KBUILD_MODNAME,
1045 	.id_table = pch_pcidev_id,
1046 	.probe = pch_i2c_probe,
1047 	.remove = __devexit_p(pch_i2c_remove),
1048 	.suspend = pch_i2c_suspend,
1049 	.resume = pch_i2c_resume
1050 };
1051 
1052 static int __init pch_pci_init(void)
1053 {
1054 	return pci_register_driver(&pch_pcidriver);
1055 }
1056 module_init(pch_pci_init);
1057 
1058 static void __exit pch_pci_exit(void)
1059 {
1060 	pci_unregister_driver(&pch_pcidriver);
1061 }
1062 module_exit(pch_pci_exit);
1063 
1064 MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semico ML7213/ML7223/ML7831 IOH I2C");
1065 MODULE_LICENSE("GPL");
1066 MODULE_AUTHOR("Tomoya MORINAGA. <tomoya.rohm@gmail.com>");
1067 module_param(pch_i2c_speed, int, (S_IRUSR | S_IWUSR));
1068 module_param(pch_clk, int, (S_IRUSR | S_IWUSR));
1069