xref: /openbmc/linux/drivers/i2c/busses/i2c-eg20t.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  * Copyright (C) 2010 OKI SEMICONDUCTOR CO., LTD.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; version 2 of the License.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
16  */
17 
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/delay.h>
21 #include <linux/init.h>
22 #include <linux/errno.h>
23 #include <linux/i2c.h>
24 #include <linux/fs.h>
25 #include <linux/io.h>
26 #include <linux/types.h>
27 #include <linux/interrupt.h>
28 #include <linux/jiffies.h>
29 #include <linux/pci.h>
30 #include <linux/mutex.h>
31 #include <linux/ktime.h>
32 
33 #define PCH_EVENT_SET	0	/* I2C Interrupt Event Set Status */
34 #define PCH_EVENT_NONE	1	/* I2C Interrupt Event Clear Status */
35 #define PCH_MAX_CLK		100000	/* Maximum Clock speed in MHz */
36 #define PCH_BUFFER_MODE_ENABLE	0x0002	/* flag for Buffer mode enable */
37 #define PCH_EEPROM_SW_RST_MODE_ENABLE	0x0008	/* EEPROM SW RST enable flag */
38 
39 #define PCH_I2CSADR	0x00	/* I2C slave address register */
40 #define PCH_I2CCTL	0x04	/* I2C control register */
41 #define PCH_I2CSR	0x08	/* I2C status register */
42 #define PCH_I2CDR	0x0C	/* I2C data register */
43 #define PCH_I2CMON	0x10	/* I2C bus monitor register */
44 #define PCH_I2CBC	0x14	/* I2C bus transfer rate setup counter */
45 #define PCH_I2CMOD	0x18	/* I2C mode register */
46 #define PCH_I2CBUFSLV	0x1C	/* I2C buffer mode slave address register */
47 #define PCH_I2CBUFSUB	0x20	/* I2C buffer mode subaddress register */
48 #define PCH_I2CBUFFOR	0x24	/* I2C buffer mode format register */
49 #define PCH_I2CBUFCTL	0x28	/* I2C buffer mode control register */
50 #define PCH_I2CBUFMSK	0x2C	/* I2C buffer mode interrupt mask register */
51 #define PCH_I2CBUFSTA	0x30	/* I2C buffer mode status register */
52 #define PCH_I2CBUFLEV	0x34	/* I2C buffer mode level register */
53 #define PCH_I2CESRFOR	0x38	/* EEPROM software reset mode format register */
54 #define PCH_I2CESRCTL	0x3C	/* EEPROM software reset mode ctrl register */
55 #define PCH_I2CESRMSK	0x40	/* EEPROM software reset mode */
56 #define PCH_I2CESRSTA	0x44	/* EEPROM software reset mode status register */
57 #define PCH_I2CTMR	0x48	/* I2C timer register */
58 #define PCH_I2CSRST	0xFC	/* I2C reset register */
59 #define PCH_I2CNF	0xF8	/* I2C noise filter register */
60 
61 #define BUS_IDLE_TIMEOUT	20
62 #define PCH_I2CCTL_I2CMEN	0x0080
63 #define TEN_BIT_ADDR_DEFAULT	0xF000
64 #define TEN_BIT_ADDR_MASK	0xF0
65 #define PCH_START		0x0020
66 #define PCH_ESR_START		0x0001
67 #define PCH_BUFF_START		0x1
68 #define PCH_REPSTART		0x0004
69 #define PCH_ACK			0x0008
70 #define PCH_GETACK		0x0001
71 #define CLR_REG			0x0
72 #define I2C_RD			0x1
73 #define I2CMCF_BIT		0x0080
74 #define I2CMIF_BIT		0x0002
75 #define I2CMAL_BIT		0x0010
76 #define I2CBMFI_BIT		0x0001
77 #define I2CBMAL_BIT		0x0002
78 #define I2CBMNA_BIT		0x0004
79 #define I2CBMTO_BIT		0x0008
80 #define I2CBMIS_BIT		0x0010
81 #define I2CESRFI_BIT		0X0001
82 #define I2CESRTO_BIT		0x0002
83 #define I2CESRFIIE_BIT		0x1
84 #define I2CESRTOIE_BIT		0x2
85 #define I2CBMDZ_BIT		0x0040
86 #define I2CBMAG_BIT		0x0020
87 #define I2CMBB_BIT		0x0020
88 #define BUFFER_MODE_MASK	(I2CBMFI_BIT | I2CBMAL_BIT | I2CBMNA_BIT | \
89 				I2CBMTO_BIT | I2CBMIS_BIT)
90 #define I2C_ADDR_MSK		0xFF
91 #define I2C_MSB_2B_MSK		0x300
92 #define FAST_MODE_CLK		400
93 #define FAST_MODE_EN		0x0001
94 #define SUB_ADDR_LEN_MAX	4
95 #define BUF_LEN_MAX		32
96 #define PCH_BUFFER_MODE		0x1
97 #define EEPROM_SW_RST_MODE	0x0002
98 #define NORMAL_INTR_ENBL	0x0300
99 #define EEPROM_RST_INTR_ENBL	(I2CESRFIIE_BIT | I2CESRTOIE_BIT)
100 #define EEPROM_RST_INTR_DISBL	0x0
101 #define BUFFER_MODE_INTR_ENBL	0x001F
102 #define BUFFER_MODE_INTR_DISBL	0x0
103 #define NORMAL_MODE		0x0
104 #define BUFFER_MODE		0x1
105 #define EEPROM_SR_MODE		0x2
106 #define I2C_TX_MODE		0x0010
107 #define PCH_BUF_TX		0xFFF7
108 #define PCH_BUF_RD		0x0008
109 #define I2C_ERROR_MASK	(I2CESRTO_EVENT | I2CBMIS_EVENT | I2CBMTO_EVENT | \
110 			I2CBMNA_EVENT | I2CBMAL_EVENT | I2CMAL_EVENT)
111 #define I2CMAL_EVENT		0x0001
112 #define I2CMCF_EVENT		0x0002
113 #define I2CBMFI_EVENT		0x0004
114 #define I2CBMAL_EVENT		0x0008
115 #define I2CBMNA_EVENT		0x0010
116 #define I2CBMTO_EVENT		0x0020
117 #define I2CBMIS_EVENT		0x0040
118 #define I2CESRFI_EVENT		0x0080
119 #define I2CESRTO_EVENT		0x0100
120 #define PCI_DEVICE_ID_PCH_I2C	0x8817
121 
122 #define pch_dbg(adap, fmt, arg...)  \
123 	dev_dbg(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
124 
125 #define pch_err(adap, fmt, arg...)  \
126 	dev_err(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
127 
128 #define pch_pci_err(pdev, fmt, arg...)  \
129 	dev_err(&pdev->dev, "%s :" fmt, __func__, ##arg)
130 
131 #define pch_pci_dbg(pdev, fmt, arg...)  \
132 	dev_dbg(&pdev->dev, "%s :" fmt, __func__, ##arg)
133 
134 /**
135  * struct i2c_algo_pch_data - for I2C driver functionalities
136  * @pch_adapter:		stores the reference to i2c_adapter structure
137  * @p_adapter_info:		stores the reference to adapter_info structure
138  * @pch_base_address:		specifies the remapped base address
139  * @pch_buff_mode_en:		specifies if buffer mode is enabled
140  * @pch_event_flag:		specifies occurrence of interrupt events
141  * @pch_i2c_xfer_in_progress:	specifies whether the transfer is completed
142  */
143 struct i2c_algo_pch_data {
144 	struct i2c_adapter pch_adapter;
145 	struct adapter_info *p_adapter_info;
146 	void __iomem *pch_base_address;
147 	int pch_buff_mode_en;
148 	u32 pch_event_flag;
149 	bool pch_i2c_xfer_in_progress;
150 };
151 
152 /**
153  * struct adapter_info - This structure holds the adapter information for the
154 			 PCH i2c controller
155  * @pch_data:		stores a list of i2c_algo_pch_data
156  * @pch_i2c_suspended:	specifies whether the system is suspended or not
157  *			perhaps with more lines and words.
158  *
159  * pch_data has as many elements as maximum I2C channels
160  */
161 struct adapter_info {
162 	struct i2c_algo_pch_data pch_data;
163 	bool pch_i2c_suspended;
164 };
165 
166 
167 static int pch_i2c_speed = 100; /* I2C bus speed in Kbps */
168 static int pch_clk = 50000;	/* specifies I2C clock speed in KHz */
169 static wait_queue_head_t pch_event;
170 static DEFINE_MUTEX(pch_mutex);
171 
172 static struct pci_device_id __devinitdata pch_pcidev_id[] = {
173 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_PCH_I2C)},
174 	{0,}
175 };
176 
177 static irqreturn_t pch_i2c_handler(int irq, void *pData);
178 
179 static inline void pch_setbit(void __iomem *addr, u32 offset, u32 bitmask)
180 {
181 	u32 val;
182 	val = ioread32(addr + offset);
183 	val |= bitmask;
184 	iowrite32(val, addr + offset);
185 }
186 
187 static inline void pch_clrbit(void __iomem *addr, u32 offset, u32 bitmask)
188 {
189 	u32 val;
190 	val = ioread32(addr + offset);
191 	val &= (~bitmask);
192 	iowrite32(val, addr + offset);
193 }
194 
195 /**
196  * pch_i2c_init() - hardware initialization of I2C module
197  * @adap:	Pointer to struct i2c_algo_pch_data.
198  */
199 static void pch_i2c_init(struct i2c_algo_pch_data *adap)
200 {
201 	void __iomem *p = adap->pch_base_address;
202 	u32 pch_i2cbc;
203 	u32 pch_i2ctmr;
204 	u32 reg_value;
205 
206 	/* reset I2C controller */
207 	iowrite32(0x01, p + PCH_I2CSRST);
208 	msleep(20);
209 	iowrite32(0x0, p + PCH_I2CSRST);
210 
211 	/* Initialize I2C registers */
212 	iowrite32(0x21, p + PCH_I2CNF);
213 
214 	pch_setbit(adap->pch_base_address, PCH_I2CCTL,
215 			  PCH_I2CCTL_I2CMEN);
216 
217 	if (pch_i2c_speed != 400)
218 		pch_i2c_speed = 100;
219 
220 	reg_value = PCH_I2CCTL_I2CMEN;
221 	if (pch_i2c_speed == FAST_MODE_CLK) {
222 		reg_value |= FAST_MODE_EN;
223 		pch_dbg(adap, "Fast mode enabled\n");
224 	}
225 
226 	if (pch_clk > PCH_MAX_CLK)
227 		pch_clk = 62500;
228 
229 	pch_i2cbc = (pch_clk + (pch_i2c_speed * 4)) / pch_i2c_speed * 8;
230 	/* Set transfer speed in I2CBC */
231 	iowrite32(pch_i2cbc, p + PCH_I2CBC);
232 
233 	pch_i2ctmr = (pch_clk) / 8;
234 	iowrite32(pch_i2ctmr, p + PCH_I2CTMR);
235 
236 	reg_value |= NORMAL_INTR_ENBL;	/* Enable interrupts in normal mode */
237 	iowrite32(reg_value, p + PCH_I2CCTL);
238 
239 	pch_dbg(adap,
240 		"I2CCTL=%x pch_i2cbc=%x pch_i2ctmr=%x Enable interrupts\n",
241 		ioread32(p + PCH_I2CCTL), pch_i2cbc, pch_i2ctmr);
242 
243 	init_waitqueue_head(&pch_event);
244 }
245 
246 static inline bool ktime_lt(const ktime_t cmp1, const ktime_t cmp2)
247 {
248 	return cmp1.tv64 < cmp2.tv64;
249 }
250 
251 /**
252  * pch_i2c_wait_for_bus_idle() - check the status of bus.
253  * @adap:	Pointer to struct i2c_algo_pch_data.
254  * @timeout:	waiting time counter (us).
255  */
256 static s32 pch_i2c_wait_for_bus_idle(struct i2c_algo_pch_data *adap,
257 				 s32 timeout)
258 {
259 	void __iomem *p = adap->pch_base_address;
260 
261 	/* MAX timeout value is timeout*1000*1000nsec */
262 	ktime_t ns_val = ktime_add_ns(ktime_get(), timeout*1000*1000);
263 	do {
264 		if ((ioread32(p + PCH_I2CSR) & I2CMBB_BIT) == 0)
265 			break;
266 		msleep(20);
267 	} while (ktime_lt(ktime_get(), ns_val));
268 
269 	pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
270 
271 	if (timeout == 0) {
272 		pch_err(adap, "%s: Timeout Error.return%d\n", __func__, -ETIME);
273 		return -ETIME;
274 	}
275 
276 	return 0;
277 }
278 
279 /**
280  * pch_i2c_start() - Generate I2C start condition in normal mode.
281  * @adap:	Pointer to struct i2c_algo_pch_data.
282  *
283  * Generate I2C start condition in normal mode by setting I2CCTL.I2CMSTA to 1.
284  */
285 static void pch_i2c_start(struct i2c_algo_pch_data *adap)
286 {
287 	void __iomem *p = adap->pch_base_address;
288 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
289 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
290 }
291 
292 /**
293  * pch_i2c_wait_for_xfer_complete() - initiates a wait for the tx complete event
294  * @adap:	Pointer to struct i2c_algo_pch_data.
295  */
296 static s32 pch_i2c_wait_for_xfer_complete(struct i2c_algo_pch_data *adap)
297 {
298 	s32 ret;
299 	ret = wait_event_timeout(pch_event,
300 			(adap->pch_event_flag != 0), msecs_to_jiffies(50));
301 	if (ret < 0) {
302 		pch_err(adap, "timeout: %x\n", adap->pch_event_flag);
303 		return ret;
304 	}
305 
306 	if (ret == 0) {
307 		pch_err(adap, "timeout: %x\n", adap->pch_event_flag);
308 		return -ETIMEDOUT;
309 	}
310 
311 	if (adap->pch_event_flag & I2C_ERROR_MASK) {
312 		pch_err(adap, "error bits set: %x\n", adap->pch_event_flag);
313 		return -EIO;
314 	}
315 
316 	adap->pch_event_flag = 0;
317 
318 	return 0;
319 }
320 
321 /**
322  * pch_i2c_getack() - to confirm ACK/NACK
323  * @adap:	Pointer to struct i2c_algo_pch_data.
324  */
325 static s32 pch_i2c_getack(struct i2c_algo_pch_data *adap)
326 {
327 	u32 reg_val;
328 	void __iomem *p = adap->pch_base_address;
329 	reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
330 
331 	if (reg_val != 0) {
332 		pch_err(adap, "return%d\n", -EPROTO);
333 		return -EPROTO;
334 	}
335 
336 	return 0;
337 }
338 
339 /**
340  * pch_i2c_stop() - generate stop condition in normal mode.
341  * @adap:	Pointer to struct i2c_algo_pch_data.
342  */
343 static void pch_i2c_stop(struct i2c_algo_pch_data *adap)
344 {
345 	void __iomem *p = adap->pch_base_address;
346 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
347 	/* clear the start bit */
348 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
349 }
350 
351 /**
352  * pch_i2c_repstart() - generate repeated start condition in normal mode
353  * @adap:	Pointer to struct i2c_algo_pch_data.
354  */
355 static void pch_i2c_repstart(struct i2c_algo_pch_data *adap)
356 {
357 	void __iomem *p = adap->pch_base_address;
358 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
359 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_REPSTART);
360 }
361 
362 /**
363  * pch_i2c_writebytes() - write data to I2C bus in normal mode
364  * @i2c_adap:	Pointer to the struct i2c_adapter.
365  * @last:	specifies whether last message or not.
366  *		In the case of compound mode it will be 1 for last message,
367  *		otherwise 0.
368  * @first:	specifies whether first message or not.
369  *		1 for first message otherwise 0.
370  */
371 static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
372 			      struct i2c_msg *msgs, u32 last, u32 first)
373 {
374 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
375 	u8 *buf;
376 	u32 length;
377 	u32 addr;
378 	u32 addr_2_msb;
379 	u32 addr_8_lsb;
380 	s32 wrcount;
381 	void __iomem *p = adap->pch_base_address;
382 
383 	length = msgs->len;
384 	buf = msgs->buf;
385 	addr = msgs->addr;
386 
387 	/* enable master tx */
388 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
389 
390 	pch_dbg(adap, "I2CCTL = %x msgs->len = %d\n", ioread32(p + PCH_I2CCTL),
391 		length);
392 
393 	if (first) {
394 		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
395 			return -ETIME;
396 	}
397 
398 	if (msgs->flags & I2C_M_TEN) {
399 		addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7);
400 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
401 		if (first)
402 			pch_i2c_start(adap);
403 		if (pch_i2c_wait_for_xfer_complete(adap) == 0 &&
404 		    pch_i2c_getack(adap) == 0) {
405 			addr_8_lsb = (addr & I2C_ADDR_MSK);
406 			iowrite32(addr_8_lsb, p + PCH_I2CDR);
407 		} else {
408 			pch_i2c_stop(adap);
409 			return -ETIME;
410 		}
411 	} else {
412 		/* set 7 bit slave address and R/W bit as 0 */
413 		iowrite32(addr << 1, p + PCH_I2CDR);
414 		if (first)
415 			pch_i2c_start(adap);
416 	}
417 
418 	if ((pch_i2c_wait_for_xfer_complete(adap) == 0) &&
419 	    (pch_i2c_getack(adap) == 0)) {
420 		for (wrcount = 0; wrcount < length; ++wrcount) {
421 			/* write buffer value to I2C data register */
422 			iowrite32(buf[wrcount], p + PCH_I2CDR);
423 			pch_dbg(adap, "writing %x to Data register\n",
424 				buf[wrcount]);
425 
426 			if (pch_i2c_wait_for_xfer_complete(adap) != 0)
427 				return -ETIME;
428 
429 			if (pch_i2c_getack(adap))
430 				return -EIO;
431 		}
432 
433 		/* check if this is the last message */
434 		if (last)
435 			pch_i2c_stop(adap);
436 		else
437 			pch_i2c_repstart(adap);
438 	} else {
439 		pch_i2c_stop(adap);
440 		return -EIO;
441 	}
442 
443 	pch_dbg(adap, "return=%d\n", wrcount);
444 
445 	return wrcount;
446 }
447 
448 /**
449  * pch_i2c_sendack() - send ACK
450  * @adap:	Pointer to struct i2c_algo_pch_data.
451  */
452 static void pch_i2c_sendack(struct i2c_algo_pch_data *adap)
453 {
454 	void __iomem *p = adap->pch_base_address;
455 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
456 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
457 }
458 
459 /**
460  * pch_i2c_sendnack() - send NACK
461  * @adap:	Pointer to struct i2c_algo_pch_data.
462  */
463 static void pch_i2c_sendnack(struct i2c_algo_pch_data *adap)
464 {
465 	void __iomem *p = adap->pch_base_address;
466 	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
467 	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
468 }
469 
470 /**
471  * pch_i2c_readbytes() - read data  from I2C bus in normal mode.
472  * @i2c_adap:	Pointer to the struct i2c_adapter.
473  * @msgs:	Pointer to i2c_msg structure.
474  * @last:	specifies whether last message or not.
475  * @first:	specifies whether first message or not.
476  */
477 s32 pch_i2c_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
478 		  u32 last, u32 first)
479 {
480 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
481 
482 	u8 *buf;
483 	u32 count;
484 	u32 length;
485 	u32 addr;
486 	u32 addr_2_msb;
487 	void __iomem *p = adap->pch_base_address;
488 
489 	length = msgs->len;
490 	buf = msgs->buf;
491 	addr = msgs->addr;
492 
493 	/* enable master reception */
494 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
495 
496 	if (first) {
497 		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
498 			return -ETIME;
499 	}
500 
501 	if (msgs->flags & I2C_M_TEN) {
502 		addr_2_msb = (((addr & I2C_MSB_2B_MSK) >> 7) | (I2C_RD));
503 		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
504 
505 	} else {
506 		/* 7 address bits + R/W bit */
507 		addr = (((addr) << 1) | (I2C_RD));
508 		iowrite32(addr, p + PCH_I2CDR);
509 	}
510 
511 	/* check if it is the first message */
512 	if (first)
513 		pch_i2c_start(adap);
514 
515 	if ((pch_i2c_wait_for_xfer_complete(adap) == 0) &&
516 	    (pch_i2c_getack(adap) == 0)) {
517 		pch_dbg(adap, "return %d\n", 0);
518 
519 		if (length == 0) {
520 			pch_i2c_stop(adap);
521 			ioread32(p + PCH_I2CDR); /* Dummy read needs */
522 
523 			count = length;
524 		} else {
525 			int read_index;
526 			int loop;
527 			pch_i2c_sendack(adap);
528 
529 			/* Dummy read */
530 			for (loop = 1, read_index = 0; loop < length; loop++) {
531 				buf[read_index] = ioread32(p + PCH_I2CDR);
532 
533 				if (loop != 1)
534 					read_index++;
535 
536 				if (pch_i2c_wait_for_xfer_complete(adap) != 0) {
537 					pch_i2c_stop(adap);
538 					return -ETIME;
539 				}
540 			}	/* end for */
541 
542 			pch_i2c_sendnack(adap);
543 
544 			buf[read_index] = ioread32(p + PCH_I2CDR);
545 
546 			if (length != 1)
547 				read_index++;
548 
549 			if (pch_i2c_wait_for_xfer_complete(adap) == 0) {
550 				if (last)
551 					pch_i2c_stop(adap);
552 				else
553 					pch_i2c_repstart(adap);
554 
555 				buf[read_index++] = ioread32(p + PCH_I2CDR);
556 				count = read_index;
557 			} else {
558 				count = -ETIME;
559 			}
560 
561 		}
562 	} else {
563 		count = -ETIME;
564 		pch_i2c_stop(adap);
565 	}
566 
567 	return count;
568 }
569 
570 /**
571  * pch_i2c_cb_ch0() - Interrupt handler Call back function
572  * @adap:	Pointer to struct i2c_algo_pch_data.
573  */
574 static void pch_i2c_cb_ch0(struct i2c_algo_pch_data *adap)
575 {
576 	u32 sts;
577 	void __iomem *p = adap->pch_base_address;
578 
579 	sts = ioread32(p + PCH_I2CSR);
580 	sts &= (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT);
581 	if (sts & I2CMAL_BIT)
582 		adap->pch_event_flag |= I2CMAL_EVENT;
583 
584 	if (sts & I2CMCF_BIT)
585 		adap->pch_event_flag |= I2CMCF_EVENT;
586 
587 	/* clear the applicable bits */
588 	pch_clrbit(adap->pch_base_address, PCH_I2CSR, sts);
589 
590 	pch_dbg(adap, "PCH_I2CSR = %x\n", ioread32(p + PCH_I2CSR));
591 
592 	wake_up(&pch_event);
593 }
594 
595 /**
596  * pch_i2c_handler() - interrupt handler for the PCH I2C controller
597  * @irq:	irq number.
598  * @pData:	cookie passed back to the handler function.
599  */
600 static irqreturn_t pch_i2c_handler(int irq, void *pData)
601 {
602 	s32 reg_val;
603 
604 	struct i2c_algo_pch_data *adap_data = (struct i2c_algo_pch_data *)pData;
605 	void __iomem *p = adap_data->pch_base_address;
606 	u32 mode = ioread32(p + PCH_I2CMOD) & (BUFFER_MODE | EEPROM_SR_MODE);
607 
608 	if (mode != NORMAL_MODE) {
609 		pch_err(adap_data, "I2C mode is not supported\n");
610 		return IRQ_NONE;
611 	}
612 
613 	reg_val = ioread32(p + PCH_I2CSR);
614 	if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT))
615 		pch_i2c_cb_ch0(adap_data);
616 	else
617 		return IRQ_NONE;
618 
619 	return IRQ_HANDLED;
620 }
621 
622 /**
623  * pch_i2c_xfer() - Reading adnd writing data through I2C bus
624  * @i2c_adap:	Pointer to the struct i2c_adapter.
625  * @msgs:	Pointer to i2c_msg structure.
626  * @num:	number of messages.
627  */
628 static s32 pch_i2c_xfer(struct i2c_adapter *i2c_adap,
629 		    struct i2c_msg *msgs, s32 num)
630 {
631 	struct i2c_msg *pmsg;
632 	u32 i = 0;
633 	u32 status;
634 	u32 msglen;
635 	u32 subaddrlen;
636 	s32 ret;
637 
638 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
639 
640 	ret = mutex_lock_interruptible(&pch_mutex);
641 	if (ret)
642 		return -ERESTARTSYS;
643 
644 	if (adap->p_adapter_info->pch_i2c_suspended) {
645 		mutex_unlock(&pch_mutex);
646 		return -EBUSY;
647 	}
648 
649 	pch_dbg(adap, "adap->p_adapter_info->pch_i2c_suspended is %d\n",
650 		adap->p_adapter_info->pch_i2c_suspended);
651 	/* transfer not completed */
652 	adap->pch_i2c_xfer_in_progress = true;
653 
654 	pmsg = &msgs[0];
655 	pmsg->flags |= adap->pch_buff_mode_en;
656 	status = pmsg->flags;
657 	pch_dbg(adap,
658 		"After invoking I2C_MODE_SEL :flag= 0x%x\n", status);
659 	/* calculate sub address length and message length */
660 	/* these are applicable only for buffer mode */
661 	subaddrlen = pmsg->buf[0];
662 	/* calculate actual message length excluding
663 	 * the sub address fields */
664 	msglen = (pmsg->len) - (subaddrlen + 1);
665 	if (status & (I2C_M_RD)) {
666 		pch_dbg(adap, "invoking pch_i2c_readbytes\n");
667 		ret = pch_i2c_readbytes(i2c_adap, pmsg, (i + 1 == num),
668 				   (i == 0));
669 	} else {
670 		pch_dbg(adap, "invoking pch_i2c_writebytes\n");
671 		ret = pch_i2c_writebytes(i2c_adap, pmsg, (i + 1 == num),
672 				    (i == 0));
673 	}
674 
675 	adap->pch_i2c_xfer_in_progress = false;	/* transfer completed */
676 
677 	mutex_unlock(&pch_mutex);
678 
679 	return ret;
680 }
681 
682 /**
683  * pch_i2c_func() - return the functionality of the I2C driver
684  * @adap:	Pointer to struct i2c_algo_pch_data.
685  */
686 static u32 pch_i2c_func(struct i2c_adapter *adap)
687 {
688 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
689 }
690 
691 static struct i2c_algorithm pch_algorithm = {
692 	.master_xfer = pch_i2c_xfer,
693 	.functionality = pch_i2c_func
694 };
695 
696 /**
697  * pch_i2c_disbl_int() - Disable PCH I2C interrupts
698  * @adap:	Pointer to struct i2c_algo_pch_data.
699  */
700 static void pch_i2c_disbl_int(struct i2c_algo_pch_data *adap)
701 {
702 	void __iomem *p = adap->pch_base_address;
703 
704 	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, NORMAL_INTR_ENBL);
705 
706 	iowrite32(EEPROM_RST_INTR_DISBL, p + PCH_I2CESRMSK);
707 
708 	iowrite32(BUFFER_MODE_INTR_DISBL, p + PCH_I2CBUFMSK);
709 }
710 
711 static int __devinit pch_i2c_probe(struct pci_dev *pdev,
712 			       const struct pci_device_id *id)
713 {
714 	void __iomem *base_addr;
715 	s32 ret;
716 	struct adapter_info *adap_info;
717 
718 	pch_pci_dbg(pdev, "Entered.\n");
719 
720 	adap_info = kzalloc((sizeof(struct adapter_info)), GFP_KERNEL);
721 	if (adap_info == NULL) {
722 		pch_pci_err(pdev, "Memory allocation FAILED\n");
723 		return -ENOMEM;
724 	}
725 
726 	ret = pci_enable_device(pdev);
727 	if (ret) {
728 		pch_pci_err(pdev, "pci_enable_device FAILED\n");
729 		goto err_pci_enable;
730 	}
731 
732 	ret = pci_request_regions(pdev, KBUILD_MODNAME);
733 	if (ret) {
734 		pch_pci_err(pdev, "pci_request_regions FAILED\n");
735 		goto err_pci_req;
736 	}
737 
738 	base_addr = pci_iomap(pdev, 1, 0);
739 
740 	if (base_addr == NULL) {
741 		pch_pci_err(pdev, "pci_iomap FAILED\n");
742 		ret = -ENOMEM;
743 		goto err_pci_iomap;
744 	}
745 
746 	adap_info->pch_i2c_suspended = false;
747 
748 	adap_info->pch_data.p_adapter_info = adap_info;
749 
750 	adap_info->pch_data.pch_adapter.owner = THIS_MODULE;
751 	adap_info->pch_data.pch_adapter.class = I2C_CLASS_HWMON;
752 	strcpy(adap_info->pch_data.pch_adapter.name, KBUILD_MODNAME);
753 	adap_info->pch_data.pch_adapter.algo = &pch_algorithm;
754 	adap_info->pch_data.pch_adapter.algo_data =
755 						&adap_info->pch_data;
756 
757 	/* (i * 0x80) + base_addr; */
758 	adap_info->pch_data.pch_base_address = base_addr;
759 
760 	adap_info->pch_data.pch_adapter.dev.parent = &pdev->dev;
761 
762 	ret = i2c_add_adapter(&(adap_info->pch_data.pch_adapter));
763 
764 	if (ret) {
765 		pch_pci_err(pdev, "i2c_add_adapter FAILED\n");
766 		goto err_i2c_add_adapter;
767 	}
768 
769 	pch_i2c_init(&adap_info->pch_data);
770 	ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED,
771 		  KBUILD_MODNAME, &adap_info->pch_data);
772 	if (ret) {
773 		pch_pci_err(pdev, "request_irq FAILED\n");
774 		goto err_request_irq;
775 	}
776 
777 	pci_set_drvdata(pdev, adap_info);
778 	pch_pci_dbg(pdev, "returns %d.\n", ret);
779 	return 0;
780 
781 err_request_irq:
782 	i2c_del_adapter(&(adap_info->pch_data.pch_adapter));
783 err_i2c_add_adapter:
784 	pci_iounmap(pdev, base_addr);
785 err_pci_iomap:
786 	pci_release_regions(pdev);
787 err_pci_req:
788 	pci_disable_device(pdev);
789 err_pci_enable:
790 	kfree(adap_info);
791 	return ret;
792 }
793 
794 static void __devexit pch_i2c_remove(struct pci_dev *pdev)
795 {
796 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
797 
798 	pch_i2c_disbl_int(&adap_info->pch_data);
799 	free_irq(pdev->irq, &adap_info->pch_data);
800 	i2c_del_adapter(&(adap_info->pch_data.pch_adapter));
801 
802 	if (adap_info->pch_data.pch_base_address) {
803 		pci_iounmap(pdev, adap_info->pch_data.pch_base_address);
804 		adap_info->pch_data.pch_base_address = 0;
805 	}
806 
807 	pci_set_drvdata(pdev, NULL);
808 
809 	pci_release_regions(pdev);
810 
811 	pci_disable_device(pdev);
812 	kfree(adap_info);
813 }
814 
815 #ifdef CONFIG_PM
816 static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
817 {
818 	int ret;
819 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
820 	void __iomem *p = adap_info->pch_data.pch_base_address;
821 
822 	adap_info->pch_i2c_suspended = true;
823 
824 	while ((adap_info->pch_data.pch_i2c_xfer_in_progress)) {
825 		/* Wait until all channel transfers are completed */
826 		msleep(20);
827 	}
828 	/* Disable the i2c interrupts */
829 	pch_i2c_disbl_int(&adap_info->pch_data);
830 
831 	pch_pci_dbg(pdev, "I2CSR = %x I2CBUFSTA = %x I2CESRSTA = %x "
832 		"invoked function pch_i2c_disbl_int successfully\n",
833 		ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
834 		ioread32(p + PCH_I2CESRSTA));
835 
836 	ret = pci_save_state(pdev);
837 
838 	if (ret) {
839 		pch_pci_err(pdev, "pci_save_state\n");
840 		return ret;
841 	}
842 
843 	pci_enable_wake(pdev, PCI_D3hot, 0);
844 	pci_disable_device(pdev);
845 	pci_set_power_state(pdev, pci_choose_state(pdev, state));
846 
847 	return 0;
848 }
849 
850 static int pch_i2c_resume(struct pci_dev *pdev)
851 {
852 	struct adapter_info *adap_info = pci_get_drvdata(pdev);
853 
854 	pci_set_power_state(pdev, PCI_D0);
855 	pci_restore_state(pdev);
856 
857 	if (pci_enable_device(pdev) < 0) {
858 		pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
859 		return -EIO;
860 	}
861 
862 	pci_enable_wake(pdev, PCI_D3hot, 0);
863 
864 	pch_i2c_init(&adap_info->pch_data);
865 
866 	adap_info->pch_i2c_suspended = false;
867 
868 	return 0;
869 }
870 #else
871 #define pch_i2c_suspend NULL
872 #define pch_i2c_resume NULL
873 #endif
874 
875 static struct pci_driver pch_pcidriver = {
876 	.name = KBUILD_MODNAME,
877 	.id_table = pch_pcidev_id,
878 	.probe = pch_i2c_probe,
879 	.remove = __devexit_p(pch_i2c_remove),
880 	.suspend = pch_i2c_suspend,
881 	.resume = pch_i2c_resume
882 };
883 
884 static int __init pch_pci_init(void)
885 {
886 	return pci_register_driver(&pch_pcidriver);
887 }
888 module_init(pch_pci_init);
889 
890 static void __exit pch_pci_exit(void)
891 {
892 	pci_unregister_driver(&pch_pcidriver);
893 }
894 module_exit(pch_pci_exit);
895 
896 MODULE_DESCRIPTION("PCH I2C PCI Driver");
897 MODULE_LICENSE("GPL");
898 MODULE_AUTHOR("Tomoya MORINAGA. <tomoya-linux@dsn.okisemi.com>");
899 module_param(pch_i2c_speed, int, (S_IRUSR | S_IWUSR));
900 module_param(pch_clk, int, (S_IRUSR | S_IWUSR));
901