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i2c-eg20t: fix race between i2c init and interrupt enable
[deliverable/linux.git] / drivers / i2c / busses / i2c-eg20t.c
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
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/delay.h>
17 #include <linux/errno.h>
18 #include <linux/i2c.h>
19 #include <linux/fs.h>
20 #include <linux/io.h>
21 #include <linux/types.h>
22 #include <linux/interrupt.h>
23 #include <linux/jiffies.h>
24 #include <linux/pci.h>
25 #include <linux/mutex.h>
26 #include <linux/ktime.h>
27 #include <linux/slab.h>
28
29 #define PCH_EVENT_SET 0 /* I2C Interrupt Event Set Status */
30 #define PCH_EVENT_NONE 1 /* I2C Interrupt Event Clear Status */
31 #define PCH_MAX_CLK 100000 /* Maximum Clock speed in MHz */
32 #define PCH_BUFFER_MODE_ENABLE 0x0002 /* flag for Buffer mode enable */
33 #define PCH_EEPROM_SW_RST_MODE_ENABLE 0x0008 /* EEPROM SW RST enable flag */
34
35 #define PCH_I2CSADR 0x00 /* I2C slave address register */
36 #define PCH_I2CCTL 0x04 /* I2C control register */
37 #define PCH_I2CSR 0x08 /* I2C status register */
38 #define PCH_I2CDR 0x0C /* I2C data register */
39 #define PCH_I2CMON 0x10 /* I2C bus monitor register */
40 #define PCH_I2CBC 0x14 /* I2C bus transfer rate setup counter */
41 #define PCH_I2CMOD 0x18 /* I2C mode register */
42 #define PCH_I2CBUFSLV 0x1C /* I2C buffer mode slave address register */
43 #define PCH_I2CBUFSUB 0x20 /* I2C buffer mode subaddress register */
44 #define PCH_I2CBUFFOR 0x24 /* I2C buffer mode format register */
45 #define PCH_I2CBUFCTL 0x28 /* I2C buffer mode control register */
46 #define PCH_I2CBUFMSK 0x2C /* I2C buffer mode interrupt mask register */
47 #define PCH_I2CBUFSTA 0x30 /* I2C buffer mode status register */
48 #define PCH_I2CBUFLEV 0x34 /* I2C buffer mode level register */
49 #define PCH_I2CESRFOR 0x38 /* EEPROM software reset mode format register */
50 #define PCH_I2CESRCTL 0x3C /* EEPROM software reset mode ctrl register */
51 #define PCH_I2CESRMSK 0x40 /* EEPROM software reset mode */
52 #define PCH_I2CESRSTA 0x44 /* EEPROM software reset mode status register */
53 #define PCH_I2CTMR 0x48 /* I2C timer register */
54 #define PCH_I2CSRST 0xFC /* I2C reset register */
55 #define PCH_I2CNF 0xF8 /* I2C noise filter register */
56
57 #define BUS_IDLE_TIMEOUT 20
58 #define PCH_I2CCTL_I2CMEN 0x0080
59 #define TEN_BIT_ADDR_DEFAULT 0xF000
60 #define TEN_BIT_ADDR_MASK 0xF0
61 #define PCH_START 0x0020
62 #define PCH_RESTART 0x0004
63 #define PCH_ESR_START 0x0001
64 #define PCH_BUFF_START 0x1
65 #define PCH_REPSTART 0x0004
66 #define PCH_ACK 0x0008
67 #define PCH_GETACK 0x0001
68 #define CLR_REG 0x0
69 #define I2C_RD 0x1
70 #define I2CMCF_BIT 0x0080
71 #define I2CMIF_BIT 0x0002
72 #define I2CMAL_BIT 0x0010
73 #define I2CBMFI_BIT 0x0001
74 #define I2CBMAL_BIT 0x0002
75 #define I2CBMNA_BIT 0x0004
76 #define I2CBMTO_BIT 0x0008
77 #define I2CBMIS_BIT 0x0010
78 #define I2CESRFI_BIT 0X0001
79 #define I2CESRTO_BIT 0x0002
80 #define I2CESRFIIE_BIT 0x1
81 #define I2CESRTOIE_BIT 0x2
82 #define I2CBMDZ_BIT 0x0040
83 #define I2CBMAG_BIT 0x0020
84 #define I2CMBB_BIT 0x0020
85 #define BUFFER_MODE_MASK (I2CBMFI_BIT | I2CBMAL_BIT | I2CBMNA_BIT | \
86 I2CBMTO_BIT | I2CBMIS_BIT)
87 #define I2C_ADDR_MSK 0xFF
88 #define I2C_MSB_2B_MSK 0x300
89 #define FAST_MODE_CLK 400
90 #define FAST_MODE_EN 0x0001
91 #define SUB_ADDR_LEN_MAX 4
92 #define BUF_LEN_MAX 32
93 #define PCH_BUFFER_MODE 0x1
94 #define EEPROM_SW_RST_MODE 0x0002
95 #define NORMAL_INTR_ENBL 0x0300
96 #define EEPROM_RST_INTR_ENBL (I2CESRFIIE_BIT | I2CESRTOIE_BIT)
97 #define EEPROM_RST_INTR_DISBL 0x0
98 #define BUFFER_MODE_INTR_ENBL 0x001F
99 #define BUFFER_MODE_INTR_DISBL 0x0
100 #define NORMAL_MODE 0x0
101 #define BUFFER_MODE 0x1
102 #define EEPROM_SR_MODE 0x2
103 #define I2C_TX_MODE 0x0010
104 #define PCH_BUF_TX 0xFFF7
105 #define PCH_BUF_RD 0x0008
106 #define I2C_ERROR_MASK (I2CESRTO_EVENT | I2CBMIS_EVENT | I2CBMTO_EVENT | \
107 I2CBMNA_EVENT | I2CBMAL_EVENT | I2CMAL_EVENT)
108 #define I2CMAL_EVENT 0x0001
109 #define I2CMCF_EVENT 0x0002
110 #define I2CBMFI_EVENT 0x0004
111 #define I2CBMAL_EVENT 0x0008
112 #define I2CBMNA_EVENT 0x0010
113 #define I2CBMTO_EVENT 0x0020
114 #define I2CBMIS_EVENT 0x0040
115 #define I2CESRFI_EVENT 0x0080
116 #define I2CESRTO_EVENT 0x0100
117 #define PCI_DEVICE_ID_PCH_I2C 0x8817
118
119 #define pch_dbg(adap, fmt, arg...) \
120 dev_dbg(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
121
122 #define pch_err(adap, fmt, arg...) \
123 dev_err(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
124
125 #define pch_pci_err(pdev, fmt, arg...) \
126 dev_err(&pdev->dev, "%s :" fmt, __func__, ##arg)
127
128 #define pch_pci_dbg(pdev, fmt, arg...) \
129 dev_dbg(&pdev->dev, "%s :" fmt, __func__, ##arg)
130
131 /*
132 Set the number of I2C instance max
133 Intel EG20T PCH : 1ch
134 LAPIS Semiconductor ML7213 IOH : 2ch
135 LAPIS Semiconductor ML7831 IOH : 1ch
136 */
137 #define PCH_I2C_MAX_DEV 2
138
139 /**
140 * struct i2c_algo_pch_data - for I2C driver functionalities
141 * @pch_adapter: stores the reference to i2c_adapter structure
142 * @p_adapter_info: stores the reference to adapter_info structure
143 * @pch_base_address: specifies the remapped base address
144 * @pch_buff_mode_en: specifies if buffer mode is enabled
145 * @pch_event_flag: specifies occurrence of interrupt events
146 * @pch_i2c_xfer_in_progress: specifies whether the transfer is completed
147 */
148 struct i2c_algo_pch_data {
149 struct i2c_adapter pch_adapter;
150 struct adapter_info *p_adapter_info;
151 void __iomem *pch_base_address;
152 int pch_buff_mode_en;
153 u32 pch_event_flag;
154 bool pch_i2c_xfer_in_progress;
155 };
156
157 /**
158 * struct adapter_info - This structure holds the adapter information for the
159 PCH i2c controller
160 * @pch_data: stores a list of i2c_algo_pch_data
161 * @pch_i2c_suspended: specifies whether the system is suspended or not
162 * perhaps with more lines and words.
163 * @ch_num: specifies the number of i2c instance
164 *
165 * pch_data has as many elements as maximum I2C channels
166 */
167 struct adapter_info {
168 struct i2c_algo_pch_data pch_data[PCH_I2C_MAX_DEV];
169 bool pch_i2c_suspended;
170 int ch_num;
171 };
172
173
174 static int pch_i2c_speed = 100; /* I2C bus speed in Kbps */
175 static int pch_clk = 50000; /* specifies I2C clock speed in KHz */
176 static wait_queue_head_t pch_event;
177 static DEFINE_MUTEX(pch_mutex);
178
179 /* Definition for ML7213 by LAPIS Semiconductor */
180 #define PCI_VENDOR_ID_ROHM 0x10DB
181 #define PCI_DEVICE_ID_ML7213_I2C 0x802D
182 #define PCI_DEVICE_ID_ML7223_I2C 0x8010
183 #define PCI_DEVICE_ID_ML7831_I2C 0x8817
184
185 static const struct pci_device_id pch_pcidev_id[] = {
186 { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PCH_I2C), 1, },
187 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_I2C), 2, },
188 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_I2C), 1, },
189 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_I2C), 1, },
190 {0,}
191 };
192
193 static irqreturn_t pch_i2c_handler(int irq, void *pData);
194
195 static inline void pch_setbit(void __iomem *addr, u32 offset, u32 bitmask)
196 {
197 u32 val;
198 val = ioread32(addr + offset);
199 val |= bitmask;
200 iowrite32(val, addr + offset);
201 }
202
203 static inline void pch_clrbit(void __iomem *addr, u32 offset, u32 bitmask)
204 {
205 u32 val;
206 val = ioread32(addr + offset);
207 val &= (~bitmask);
208 iowrite32(val, addr + offset);
209 }
210
211 /**
212 * pch_i2c_init() - hardware initialization of I2C module
213 * @adap: Pointer to struct i2c_algo_pch_data.
214 */
215 static void pch_i2c_init(struct i2c_algo_pch_data *adap)
216 {
217 void __iomem *p = adap->pch_base_address;
218 u32 pch_i2cbc;
219 u32 pch_i2ctmr;
220 u32 reg_value;
221
222 /* reset I2C controller */
223 iowrite32(0x01, p + PCH_I2CSRST);
224 msleep(20);
225 iowrite32(0x0, p + PCH_I2CSRST);
226
227 /* Initialize I2C registers */
228 iowrite32(0x21, p + PCH_I2CNF);
229
230 pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_I2CCTL_I2CMEN);
231
232 if (pch_i2c_speed != 400)
233 pch_i2c_speed = 100;
234
235 reg_value = PCH_I2CCTL_I2CMEN;
236 if (pch_i2c_speed == FAST_MODE_CLK) {
237 reg_value |= FAST_MODE_EN;
238 pch_dbg(adap, "Fast mode enabled\n");
239 }
240
241 if (pch_clk > PCH_MAX_CLK)
242 pch_clk = 62500;
243
244 pch_i2cbc = (pch_clk + (pch_i2c_speed * 4)) / (pch_i2c_speed * 8);
245 /* Set transfer speed in I2CBC */
246 iowrite32(pch_i2cbc, p + PCH_I2CBC);
247
248 pch_i2ctmr = (pch_clk) / 8;
249 iowrite32(pch_i2ctmr, p + PCH_I2CTMR);
250
251 reg_value |= NORMAL_INTR_ENBL; /* Enable interrupts in normal mode */
252 iowrite32(reg_value, p + PCH_I2CCTL);
253
254 pch_dbg(adap,
255 "I2CCTL=%x pch_i2cbc=%x pch_i2ctmr=%x Enable interrupts\n",
256 ioread32(p + PCH_I2CCTL), pch_i2cbc, pch_i2ctmr);
257
258 init_waitqueue_head(&pch_event);
259 }
260
261 /**
262 * pch_i2c_wait_for_bus_idle() - check the status of bus.
263 * @adap: Pointer to struct i2c_algo_pch_data.
264 * @timeout: waiting time counter (ms).
265 */
266 static s32 pch_i2c_wait_for_bus_idle(struct i2c_algo_pch_data *adap,
267 s32 timeout)
268 {
269 void __iomem *p = adap->pch_base_address;
270 int schedule = 0;
271 unsigned long end = jiffies + msecs_to_jiffies(timeout);
272
273 while (ioread32(p + PCH_I2CSR) & I2CMBB_BIT) {
274 if (time_after(jiffies, end)) {
275 pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
276 pch_err(adap, "%s: Timeout Error.return%d\n",
277 __func__, -ETIME);
278 pch_i2c_init(adap);
279
280 return -ETIME;
281 }
282
283 if (!schedule)
284 /* Retry after some usecs */
285 udelay(5);
286 else
287 /* Wait a bit more without consuming CPU */
288 usleep_range(20, 1000);
289
290 schedule = 1;
291 }
292
293 return 0;
294 }
295
296 /**
297 * pch_i2c_start() - Generate I2C start condition in normal mode.
298 * @adap: Pointer to struct i2c_algo_pch_data.
299 *
300 * Generate I2C start condition in normal mode by setting I2CCTL.I2CMSTA to 1.
301 */
302 static void pch_i2c_start(struct i2c_algo_pch_data *adap)
303 {
304 void __iomem *p = adap->pch_base_address;
305 pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
306 pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
307 }
308
309 /**
310 * pch_i2c_stop() - generate stop condition in normal mode.
311 * @adap: Pointer to struct i2c_algo_pch_data.
312 */
313 static void pch_i2c_stop(struct i2c_algo_pch_data *adap)
314 {
315 void __iomem *p = adap->pch_base_address;
316 pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
317 /* clear the start bit */
318 pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
319 }
320
321 static int pch_i2c_wait_for_check_xfer(struct i2c_algo_pch_data *adap)
322 {
323 long ret;
324 void __iomem *p = adap->pch_base_address;
325
326 ret = wait_event_timeout(pch_event,
327 (adap->pch_event_flag != 0), msecs_to_jiffies(1000));
328 if (!ret) {
329 pch_err(adap, "%s:wait-event timeout\n", __func__);
330 adap->pch_event_flag = 0;
331 pch_i2c_stop(adap);
332 pch_i2c_init(adap);
333 return -ETIMEDOUT;
334 }
335
336 if (adap->pch_event_flag & I2C_ERROR_MASK) {
337 pch_err(adap, "Lost Arbitration\n");
338 adap->pch_event_flag = 0;
339 pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
340 pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
341 pch_i2c_init(adap);
342 return -EAGAIN;
343 }
344
345 adap->pch_event_flag = 0;
346
347 if (ioread32(p + PCH_I2CSR) & PCH_GETACK) {
348 pch_dbg(adap, "Receive NACK for slave address setting\n");
349 return -ENXIO;
350 }
351
352 return 0;
353 }
354
355 /**
356 * pch_i2c_repstart() - generate repeated start condition in normal mode
357 * @adap: Pointer to struct i2c_algo_pch_data.
358 */
359 static void pch_i2c_repstart(struct i2c_algo_pch_data *adap)
360 {
361 void __iomem *p = adap->pch_base_address;
362 pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
363 pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_REPSTART);
364 }
365
366 /**
367 * pch_i2c_writebytes() - write data to I2C bus in normal mode
368 * @i2c_adap: Pointer to the struct i2c_adapter.
369 * @last: specifies whether last message or not.
370 * In the case of compound mode it will be 1 for last message,
371 * otherwise 0.
372 * @first: specifies whether first message or not.
373 * 1 for first message otherwise 0.
374 */
375 static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
376 struct i2c_msg *msgs, u32 last, u32 first)
377 {
378 struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
379 u8 *buf;
380 u32 length;
381 u32 addr;
382 u32 addr_2_msb;
383 u32 addr_8_lsb;
384 s32 wrcount;
385 s32 rtn;
386 void __iomem *p = adap->pch_base_address;
387
388 length = msgs->len;
389 buf = msgs->buf;
390 addr = msgs->addr;
391
392 /* enable master tx */
393 pch_setbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
394
395 pch_dbg(adap, "I2CCTL = %x msgs->len = %d\n", ioread32(p + PCH_I2CCTL),
396 length);
397
398 if (first) {
399 if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
400 return -ETIME;
401 }
402
403 if (msgs->flags & I2C_M_TEN) {
404 addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7) & 0x06;
405 iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
406 if (first)
407 pch_i2c_start(adap);
408
409 rtn = pch_i2c_wait_for_check_xfer(adap);
410 if (rtn)
411 return rtn;
412
413 addr_8_lsb = (addr & I2C_ADDR_MSK);
414 iowrite32(addr_8_lsb, p + PCH_I2CDR);
415 } else {
416 /* set 7 bit slave address and R/W bit as 0 */
417 iowrite32(addr << 1, p + PCH_I2CDR);
418 if (first)
419 pch_i2c_start(adap);
420 }
421
422 rtn = pch_i2c_wait_for_check_xfer(adap);
423 if (rtn)
424 return rtn;
425
426 for (wrcount = 0; wrcount < length; ++wrcount) {
427 /* write buffer value to I2C data register */
428 iowrite32(buf[wrcount], p + PCH_I2CDR);
429 pch_dbg(adap, "writing %x to Data register\n", buf[wrcount]);
430
431 rtn = pch_i2c_wait_for_check_xfer(adap);
432 if (rtn)
433 return rtn;
434
435 pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMCF_BIT);
436 pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
437 }
438
439 /* check if this is the last message */
440 if (last)
441 pch_i2c_stop(adap);
442 else
443 pch_i2c_repstart(adap);
444
445 pch_dbg(adap, "return=%d\n", wrcount);
446
447 return wrcount;
448 }
449
450 /**
451 * pch_i2c_sendack() - send ACK
452 * @adap: Pointer to struct i2c_algo_pch_data.
453 */
454 static void pch_i2c_sendack(struct i2c_algo_pch_data *adap)
455 {
456 void __iomem *p = adap->pch_base_address;
457 pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
458 pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
459 }
460
461 /**
462 * pch_i2c_sendnack() - send NACK
463 * @adap: Pointer to struct i2c_algo_pch_data.
464 */
465 static void pch_i2c_sendnack(struct i2c_algo_pch_data *adap)
466 {
467 void __iomem *p = adap->pch_base_address;
468 pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
469 pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
470 }
471
472 /**
473 * pch_i2c_restart() - Generate I2C restart condition in normal mode.
474 * @adap: Pointer to struct i2c_algo_pch_data.
475 *
476 * Generate I2C restart condition in normal mode by setting I2CCTL.I2CRSTA.
477 */
478 static void pch_i2c_restart(struct i2c_algo_pch_data *adap)
479 {
480 void __iomem *p = adap->pch_base_address;
481 pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
482 pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_RESTART);
483 }
484
485 /**
486 * pch_i2c_readbytes() - read data from I2C bus in normal mode.
487 * @i2c_adap: Pointer to the struct i2c_adapter.
488 * @msgs: Pointer to i2c_msg structure.
489 * @last: specifies whether last message or not.
490 * @first: specifies whether first message or not.
491 */
492 static s32 pch_i2c_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
493 u32 last, u32 first)
494 {
495 struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
496
497 u8 *buf;
498 u32 count;
499 u32 length;
500 u32 addr;
501 u32 addr_2_msb;
502 u32 addr_8_lsb;
503 void __iomem *p = adap->pch_base_address;
504 s32 rtn;
505
506 length = msgs->len;
507 buf = msgs->buf;
508 addr = msgs->addr;
509
510 /* enable master reception */
511 pch_clrbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
512
513 if (first) {
514 if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
515 return -ETIME;
516 }
517
518 if (msgs->flags & I2C_M_TEN) {
519 addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7);
520 iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
521 if (first)
522 pch_i2c_start(adap);
523
524 rtn = pch_i2c_wait_for_check_xfer(adap);
525 if (rtn)
526 return rtn;
527
528 addr_8_lsb = (addr & I2C_ADDR_MSK);
529 iowrite32(addr_8_lsb, p + PCH_I2CDR);
530
531 pch_i2c_restart(adap);
532
533 rtn = pch_i2c_wait_for_check_xfer(adap);
534 if (rtn)
535 return rtn;
536
537 addr_2_msb |= I2C_RD;
538 iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
539 } else {
540 /* 7 address bits + R/W bit */
541 addr = (((addr) << 1) | (I2C_RD));
542 iowrite32(addr, p + PCH_I2CDR);
543 }
544
545 /* check if it is the first message */
546 if (first)
547 pch_i2c_start(adap);
548
549 rtn = pch_i2c_wait_for_check_xfer(adap);
550 if (rtn)
551 return rtn;
552
553 if (length == 0) {
554 pch_i2c_stop(adap);
555 ioread32(p + PCH_I2CDR); /* Dummy read needs */
556
557 count = length;
558 } else {
559 int read_index;
560 int loop;
561 pch_i2c_sendack(adap);
562
563 /* Dummy read */
564 for (loop = 1, read_index = 0; loop < length; loop++) {
565 buf[read_index] = ioread32(p + PCH_I2CDR);
566
567 if (loop != 1)
568 read_index++;
569
570 rtn = pch_i2c_wait_for_check_xfer(adap);
571 if (rtn)
572 return rtn;
573 } /* end for */
574
575 pch_i2c_sendnack(adap);
576
577 buf[read_index] = ioread32(p + PCH_I2CDR); /* Read final - 1 */
578
579 if (length != 1)
580 read_index++;
581
582 rtn = pch_i2c_wait_for_check_xfer(adap);
583 if (rtn)
584 return rtn;
585
586 if (last)
587 pch_i2c_stop(adap);
588 else
589 pch_i2c_repstart(adap);
590
591 buf[read_index++] = ioread32(p + PCH_I2CDR); /* Read Final */
592 count = read_index;
593 }
594
595 return count;
596 }
597
598 /**
599 * pch_i2c_cb() - Interrupt handler Call back function
600 * @adap: Pointer to struct i2c_algo_pch_data.
601 */
602 static void pch_i2c_cb(struct i2c_algo_pch_data *adap)
603 {
604 u32 sts;
605 void __iomem *p = adap->pch_base_address;
606
607 sts = ioread32(p + PCH_I2CSR);
608 sts &= (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT);
609 if (sts & I2CMAL_BIT)
610 adap->pch_event_flag |= I2CMAL_EVENT;
611
612 if (sts & I2CMCF_BIT)
613 adap->pch_event_flag |= I2CMCF_EVENT;
614
615 /* clear the applicable bits */
616 pch_clrbit(adap->pch_base_address, PCH_I2CSR, sts);
617
618 pch_dbg(adap, "PCH_I2CSR = %x\n", ioread32(p + PCH_I2CSR));
619
620 wake_up(&pch_event);
621 }
622
623 /**
624 * pch_i2c_handler() - interrupt handler for the PCH I2C controller
625 * @irq: irq number.
626 * @pData: cookie passed back to the handler function.
627 */
628 static irqreturn_t pch_i2c_handler(int irq, void *pData)
629 {
630 u32 reg_val;
631 int flag;
632 int i;
633 struct adapter_info *adap_info = pData;
634 void __iomem *p;
635 u32 mode;
636
637 for (i = 0, flag = 0; i < adap_info->ch_num; i++) {
638 p = adap_info->pch_data[i].pch_base_address;
639 mode = ioread32(p + PCH_I2CMOD);
640 mode &= BUFFER_MODE | EEPROM_SR_MODE;
641 if (mode != NORMAL_MODE) {
642 pch_err(adap_info->pch_data,
643 "I2C-%d mode(%d) is not supported\n", mode, i);
644 continue;
645 }
646 reg_val = ioread32(p + PCH_I2CSR);
647 if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT)) {
648 pch_i2c_cb(&adap_info->pch_data[i]);
649 flag = 1;
650 }
651 }
652
653 return flag ? IRQ_HANDLED : IRQ_NONE;
654 }
655
656 /**
657 * pch_i2c_xfer() - Reading adnd writing data through I2C bus
658 * @i2c_adap: Pointer to the struct i2c_adapter.
659 * @msgs: Pointer to i2c_msg structure.
660 * @num: number of messages.
661 */
662 static s32 pch_i2c_xfer(struct i2c_adapter *i2c_adap,
663 struct i2c_msg *msgs, s32 num)
664 {
665 struct i2c_msg *pmsg;
666 u32 i = 0;
667 u32 status;
668 s32 ret;
669
670 struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
671
672 ret = mutex_lock_interruptible(&pch_mutex);
673 if (ret)
674 return ret;
675
676 if (adap->p_adapter_info->pch_i2c_suspended) {
677 mutex_unlock(&pch_mutex);
678 return -EBUSY;
679 }
680
681 pch_dbg(adap, "adap->p_adapter_info->pch_i2c_suspended is %d\n",
682 adap->p_adapter_info->pch_i2c_suspended);
683 /* transfer not completed */
684 adap->pch_i2c_xfer_in_progress = true;
685
686 for (i = 0; i < num && ret >= 0; i++) {
687 pmsg = &msgs[i];
688 pmsg->flags |= adap->pch_buff_mode_en;
689 status = pmsg->flags;
690 pch_dbg(adap,
691 "After invoking I2C_MODE_SEL :flag= 0x%x\n", status);
692
693 if ((status & (I2C_M_RD)) != false) {
694 ret = pch_i2c_readbytes(i2c_adap, pmsg, (i + 1 == num),
695 (i == 0));
696 } else {
697 ret = pch_i2c_writebytes(i2c_adap, pmsg, (i + 1 == num),
698 (i == 0));
699 }
700 }
701
702 adap->pch_i2c_xfer_in_progress = false; /* transfer completed */
703
704 mutex_unlock(&pch_mutex);
705
706 return (ret < 0) ? ret : num;
707 }
708
709 /**
710 * pch_i2c_func() - return the functionality of the I2C driver
711 * @adap: Pointer to struct i2c_algo_pch_data.
712 */
713 static u32 pch_i2c_func(struct i2c_adapter *adap)
714 {
715 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
716 }
717
718 static struct i2c_algorithm pch_algorithm = {
719 .master_xfer = pch_i2c_xfer,
720 .functionality = pch_i2c_func
721 };
722
723 /**
724 * pch_i2c_disbl_int() - Disable PCH I2C interrupts
725 * @adap: Pointer to struct i2c_algo_pch_data.
726 */
727 static void pch_i2c_disbl_int(struct i2c_algo_pch_data *adap)
728 {
729 void __iomem *p = adap->pch_base_address;
730
731 pch_clrbit(adap->pch_base_address, PCH_I2CCTL, NORMAL_INTR_ENBL);
732
733 iowrite32(EEPROM_RST_INTR_DISBL, p + PCH_I2CESRMSK);
734
735 iowrite32(BUFFER_MODE_INTR_DISBL, p + PCH_I2CBUFMSK);
736 }
737
738 static int pch_i2c_probe(struct pci_dev *pdev,
739 const struct pci_device_id *id)
740 {
741 void __iomem *base_addr;
742 int ret;
743 int i, j;
744 struct adapter_info *adap_info;
745 struct i2c_adapter *pch_adap;
746
747 pch_pci_dbg(pdev, "Entered.\n");
748
749 adap_info = kzalloc((sizeof(struct adapter_info)), GFP_KERNEL);
750 if (adap_info == NULL)
751 return -ENOMEM;
752
753 ret = pci_enable_device(pdev);
754 if (ret) {
755 pch_pci_err(pdev, "pci_enable_device FAILED\n");
756 goto err_pci_enable;
757 }
758
759 ret = pci_request_regions(pdev, KBUILD_MODNAME);
760 if (ret) {
761 pch_pci_err(pdev, "pci_request_regions FAILED\n");
762 goto err_pci_req;
763 }
764
765 base_addr = pci_iomap(pdev, 1, 0);
766
767 if (base_addr == NULL) {
768 pch_pci_err(pdev, "pci_iomap FAILED\n");
769 ret = -ENOMEM;
770 goto err_pci_iomap;
771 }
772
773 /* Set the number of I2C channel instance */
774 adap_info->ch_num = id->driver_data;
775
776 for (i = 0; i < adap_info->ch_num; i++) {
777 pch_adap = &adap_info->pch_data[i].pch_adapter;
778 adap_info->pch_i2c_suspended = false;
779
780 adap_info->pch_data[i].p_adapter_info = adap_info;
781
782 pch_adap->owner = THIS_MODULE;
783 pch_adap->class = I2C_CLASS_HWMON;
784 strlcpy(pch_adap->name, KBUILD_MODNAME, sizeof(pch_adap->name));
785 pch_adap->algo = &pch_algorithm;
786 pch_adap->algo_data = &adap_info->pch_data[i];
787
788 /* base_addr + offset; */
789 adap_info->pch_data[i].pch_base_address = base_addr + 0x100 * i;
790
791 pch_adap->dev.of_node = pdev->dev.of_node;
792 pch_adap->dev.parent = &pdev->dev;
793 }
794
795 ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED,
796 KBUILD_MODNAME, adap_info);
797 if (ret) {
798 pch_pci_err(pdev, "request_irq FAILED\n");
799 goto err_request_irq;
800 }
801
802 for (i = 0; i < adap_info->ch_num; i++) {
803 pch_adap = &adap_info->pch_data[i].pch_adapter;
804
805 pch_i2c_init(&adap_info->pch_data[i]);
806
807 pch_adap->nr = i;
808 ret = i2c_add_numbered_adapter(pch_adap);
809 if (ret) {
810 pch_pci_err(pdev, "i2c_add_adapter[ch:%d] FAILED\n", i);
811 goto err_add_adapter;
812 }
813 }
814
815 pci_set_drvdata(pdev, adap_info);
816 pch_pci_dbg(pdev, "returns %d.\n", ret);
817 return 0;
818
819 err_add_adapter:
820 for (j = 0; j < i; j++)
821 i2c_del_adapter(&adap_info->pch_data[j].pch_adapter);
822 free_irq(pdev->irq, adap_info);
823 err_request_irq:
824 pci_iounmap(pdev, base_addr);
825 err_pci_iomap:
826 pci_release_regions(pdev);
827 err_pci_req:
828 pci_disable_device(pdev);
829 err_pci_enable:
830 kfree(adap_info);
831 return ret;
832 }
833
834 static void pch_i2c_remove(struct pci_dev *pdev)
835 {
836 int i;
837 struct adapter_info *adap_info = pci_get_drvdata(pdev);
838
839 free_irq(pdev->irq, adap_info);
840
841 for (i = 0; i < adap_info->ch_num; i++) {
842 pch_i2c_disbl_int(&adap_info->pch_data[i]);
843 i2c_del_adapter(&adap_info->pch_data[i].pch_adapter);
844 }
845
846 if (adap_info->pch_data[0].pch_base_address)
847 pci_iounmap(pdev, adap_info->pch_data[0].pch_base_address);
848
849 for (i = 0; i < adap_info->ch_num; i++)
850 adap_info->pch_data[i].pch_base_address = NULL;
851
852 pci_release_regions(pdev);
853
854 pci_disable_device(pdev);
855 kfree(adap_info);
856 }
857
858 #ifdef CONFIG_PM
859 static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
860 {
861 int ret;
862 int i;
863 struct adapter_info *adap_info = pci_get_drvdata(pdev);
864 void __iomem *p = adap_info->pch_data[0].pch_base_address;
865
866 adap_info->pch_i2c_suspended = true;
867
868 for (i = 0; i < adap_info->ch_num; i++) {
869 while ((adap_info->pch_data[i].pch_i2c_xfer_in_progress)) {
870 /* Wait until all channel transfers are completed */
871 msleep(20);
872 }
873 }
874
875 /* Disable the i2c interrupts */
876 for (i = 0; i < adap_info->ch_num; i++)
877 pch_i2c_disbl_int(&adap_info->pch_data[i]);
878
879 pch_pci_dbg(pdev, "I2CSR = %x I2CBUFSTA = %x I2CESRSTA = %x "
880 "invoked function pch_i2c_disbl_int successfully\n",
881 ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
882 ioread32(p + PCH_I2CESRSTA));
883
884 ret = pci_save_state(pdev);
885
886 if (ret) {
887 pch_pci_err(pdev, "pci_save_state\n");
888 return ret;
889 }
890
891 pci_enable_wake(pdev, PCI_D3hot, 0);
892 pci_disable_device(pdev);
893 pci_set_power_state(pdev, pci_choose_state(pdev, state));
894
895 return 0;
896 }
897
898 static int pch_i2c_resume(struct pci_dev *pdev)
899 {
900 int i;
901 struct adapter_info *adap_info = pci_get_drvdata(pdev);
902
903 pci_set_power_state(pdev, PCI_D0);
904 pci_restore_state(pdev);
905
906 if (pci_enable_device(pdev) < 0) {
907 pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
908 return -EIO;
909 }
910
911 pci_enable_wake(pdev, PCI_D3hot, 0);
912
913 for (i = 0; i < adap_info->ch_num; i++)
914 pch_i2c_init(&adap_info->pch_data[i]);
915
916 adap_info->pch_i2c_suspended = false;
917
918 return 0;
919 }
920 #else
921 #define pch_i2c_suspend NULL
922 #define pch_i2c_resume NULL
923 #endif
924
925 static struct pci_driver pch_pcidriver = {
926 .name = KBUILD_MODNAME,
927 .id_table = pch_pcidev_id,
928 .probe = pch_i2c_probe,
929 .remove = pch_i2c_remove,
930 .suspend = pch_i2c_suspend,
931 .resume = pch_i2c_resume
932 };
933
934 module_pci_driver(pch_pcidriver);
935
936 MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semico ML7213/ML7223/ML7831 IOH I2C");
937 MODULE_LICENSE("GPL");
938 MODULE_AUTHOR("Tomoya MORINAGA. <tomoya.rohm@gmail.com>");
939 module_param(pch_i2c_speed, int, (S_IRUSR | S_IWUSR));
940 module_param(pch_clk, int, (S_IRUSR | S_IWUSR));
Linux kernel - Deliverables
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