xref: /linux/drivers/sbus/char/envctrl.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
1 /* $Id: envctrl.c,v 1.25 2002/01/15 09:01:26 davem Exp $
2  * envctrl.c: Temperature and Fan monitoring on Machines providing it.
3  *
4  * Copyright (C) 1998  Eddie C. Dost  (ecd@skynet.be)
5  * Copyright (C) 2000  Vinh Truong    (vinh.truong@eng.sun.com)
6  * VT - The implementation is to support Sun Microelectronics (SME) platform
7  *      environment monitoring.  SME platforms use pcf8584 as the i2c bus
8  *      controller to access pcf8591 (8-bit A/D and D/A converter) and
9  *      pcf8571 (256 x 8-bit static low-voltage RAM with I2C-bus interface).
10  *      At board level, it follows SME Firmware I2C Specification. Reference:
11  * 	http://www-eu2.semiconductors.com/pip/PCF8584P
12  * 	http://www-eu2.semiconductors.com/pip/PCF8574AP
13  * 	http://www-eu2.semiconductors.com/pip/PCF8591P
14  *
15  * EB - Added support for CP1500 Global Address and PS/Voltage monitoring.
16  * 		Eric Brower <ebrower@usa.net>
17  *
18  * DB - Audit every copy_to_user in envctrl_read.
19  *              Daniele Bellucci <bellucda@tiscali.it>
20  */
21 
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/kthread.h>
25 #include <linux/delay.h>
26 #include <linux/ioport.h>
27 #include <linux/miscdevice.h>
28 #include <linux/kmod.h>
29 
30 #include <asm/ebus.h>
31 #include <asm/uaccess.h>
32 #include <asm/envctrl.h>
33 
34 #define ENVCTRL_MINOR	162
35 
36 #define PCF8584_ADDRESS	0x55
37 
38 #define CONTROL_PIN	0x80
39 #define CONTROL_ES0	0x40
40 #define CONTROL_ES1	0x20
41 #define CONTROL_ES2	0x10
42 #define CONTROL_ENI	0x08
43 #define CONTROL_STA	0x04
44 #define CONTROL_STO	0x02
45 #define CONTROL_ACK	0x01
46 
47 #define STATUS_PIN	0x80
48 #define STATUS_STS	0x20
49 #define STATUS_BER	0x10
50 #define STATUS_LRB	0x08
51 #define STATUS_AD0	0x08
52 #define STATUS_AAB	0x04
53 #define STATUS_LAB	0x02
54 #define STATUS_BB	0x01
55 
56 /*
57  * CLK Mode Register.
58  */
59 #define BUS_CLK_90	0x00
60 #define BUS_CLK_45	0x01
61 #define BUS_CLK_11	0x02
62 #define BUS_CLK_1_5	0x03
63 
64 #define CLK_3		0x00
65 #define CLK_4_43	0x10
66 #define CLK_6		0x14
67 #define CLK_8		0x18
68 #define CLK_12		0x1c
69 
70 #define OBD_SEND_START	0xc5    /* value to generate I2c_bus START condition */
71 #define OBD_SEND_STOP 	0xc3    /* value to generate I2c_bus STOP condition */
72 
73 /* Monitor type of i2c child device.
74  * Firmware definitions.
75  */
76 #define PCF8584_MAX_CHANNELS            8
77 #define PCF8584_GLOBALADDR_TYPE			6  /* global address monitor */
78 #define PCF8584_FANSTAT_TYPE            3  /* fan status monitor */
79 #define PCF8584_VOLTAGE_TYPE            2  /* voltage monitor    */
80 #define PCF8584_TEMP_TYPE	        	1  /* temperature monitor*/
81 
82 /* Monitor type of i2c child device.
83  * Driver definitions.
84  */
85 #define ENVCTRL_NOMON				0
86 #define ENVCTRL_CPUTEMP_MON			1    /* cpu temperature monitor */
87 #define ENVCTRL_CPUVOLTAGE_MON	  	2    /* voltage monitor         */
88 #define ENVCTRL_FANSTAT_MON  		3    /* fan status monitor      */
89 #define ENVCTRL_ETHERTEMP_MON		4    /* ethernet temperarture */
90 					     /* monitor                     */
91 #define ENVCTRL_VOLTAGESTAT_MON	  	5    /* voltage status monitor  */
92 #define ENVCTRL_MTHRBDTEMP_MON		6    /* motherboard temperature */
93 #define ENVCTRL_SCSITEMP_MON		7    /* scsi temperarture */
94 #define ENVCTRL_GLOBALADDR_MON		8    /* global address */
95 
96 /* Child device type.
97  * Driver definitions.
98  */
99 #define I2C_ADC				0    /* pcf8591 */
100 #define I2C_GPIO			1    /* pcf8571 */
101 
102 /* Data read from child device may need to decode
103  * through a data table and a scale.
104  * Translation type as defined by firmware.
105  */
106 #define ENVCTRL_TRANSLATE_NO		0
107 #define ENVCTRL_TRANSLATE_PARTIAL	1
108 #define ENVCTRL_TRANSLATE_COMBINED	2
109 #define ENVCTRL_TRANSLATE_FULL		3     /* table[data] */
110 #define ENVCTRL_TRANSLATE_SCALE		4     /* table[data]/scale */
111 
112 /* Driver miscellaneous definitions. */
113 #define ENVCTRL_MAX_CPU			4
114 #define CHANNEL_DESC_SZ			256
115 
116 /* Mask values for combined GlobalAddress/PowerStatus node */
117 #define ENVCTRL_GLOBALADDR_ADDR_MASK 	0x1F
118 #define ENVCTRL_GLOBALADDR_PSTAT_MASK	0x60
119 
120 /* Node 0x70 ignored on CompactPCI CP1400/1500 platforms
121  * (see envctrl_init_i2c_child)
122  */
123 #define ENVCTRL_CPCI_IGNORED_NODE		0x70
124 
125 #define PCF8584_DATA	0x00
126 #define PCF8584_CSR	0x01
127 
128 /* Each child device can be monitored by up to PCF8584_MAX_CHANNELS.
129  * Property of a port or channel as defined by the firmware.
130  */
131 struct pcf8584_channel {
132         unsigned char chnl_no;
133         unsigned char io_direction;
134         unsigned char type;
135         unsigned char last;
136 };
137 
138 /* Each child device may have one or more tables of bytes to help decode
139  * data. Table property as defined by the firmware.
140  */
141 struct pcf8584_tblprop {
142         unsigned int type;
143         unsigned int scale;
144         unsigned int offset; /* offset from the beginning of the table */
145         unsigned int size;
146 };
147 
148 /* i2c child */
149 struct i2c_child_t {
150 	/* Either ADC or GPIO. */
151 	unsigned char i2ctype;
152         unsigned long addr;
153         struct pcf8584_channel chnl_array[PCF8584_MAX_CHANNELS];
154 
155 	/* Channel info. */
156 	unsigned int total_chnls;	/* Number of monitor channels. */
157 	unsigned char fan_mask;		/* Byte mask for fan status channels. */
158 	unsigned char voltage_mask;	/* Byte mask for voltage status channels. */
159         struct pcf8584_tblprop tblprop_array[PCF8584_MAX_CHANNELS];
160 
161 	/* Properties of all monitor channels. */
162 	unsigned int total_tbls;	/* Number of monitor tables. */
163         char *tables;			/* Pointer to table(s). */
164 	char chnls_desc[CHANNEL_DESC_SZ]; /* Channel description. */
165 	char mon_type[PCF8584_MAX_CHANNELS];
166 };
167 
168 static void __iomem *i2c;
169 static struct i2c_child_t i2c_childlist[ENVCTRL_MAX_CPU*2];
170 static unsigned char chnls_mask[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
171 static unsigned int warning_temperature = 0;
172 static unsigned int shutdown_temperature = 0;
173 static char read_cpu;
174 
175 /* Forward declarations. */
176 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char);
177 
178 /* Function Description: Test the PIN bit (Pending Interrupt Not)
179  * 			 to test when serial transmission is completed .
180  * Return : None.
181  */
182 static void envtrl_i2c_test_pin(void)
183 {
184 	int limit = 1000000;
185 
186 	while (--limit > 0) {
187 		if (!(readb(i2c + PCF8584_CSR) & STATUS_PIN))
188 			break;
189 		udelay(1);
190 	}
191 
192 	if (limit <= 0)
193 		printk(KERN_INFO "envctrl: Pin status will not clear.\n");
194 }
195 
196 /* Function Description: Test busy bit.
197  * Return : None.
198  */
199 static void envctrl_i2c_test_bb(void)
200 {
201 	int limit = 1000000;
202 
203 	while (--limit > 0) {
204 		/* Busy bit 0 means busy. */
205 		if (readb(i2c + PCF8584_CSR) & STATUS_BB)
206 			break;
207 		udelay(1);
208 	}
209 
210 	if (limit <= 0)
211 		printk(KERN_INFO "envctrl: Busy bit will not clear.\n");
212 }
213 
214 /* Function Description: Send the address for a read access.
215  * Return : 0 if not acknowledged, otherwise acknowledged.
216  */
217 static int envctrl_i2c_read_addr(unsigned char addr)
218 {
219 	envctrl_i2c_test_bb();
220 
221 	/* Load address. */
222 	writeb(addr + 1, i2c + PCF8584_DATA);
223 
224 	envctrl_i2c_test_bb();
225 
226 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
227 
228 	/* Wait for PIN. */
229 	envtrl_i2c_test_pin();
230 
231 	/* CSR 0 means acknowledged. */
232 	if (!(readb(i2c + PCF8584_CSR) & STATUS_LRB)) {
233 		return readb(i2c + PCF8584_DATA);
234 	} else {
235 		writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
236 		return 0;
237 	}
238 }
239 
240 /* Function Description: Send the address for write mode.
241  * Return : None.
242  */
243 static void envctrl_i2c_write_addr(unsigned char addr)
244 {
245 	envctrl_i2c_test_bb();
246 	writeb(addr, i2c + PCF8584_DATA);
247 
248 	/* Generate Start condition. */
249 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
250 }
251 
252 /* Function Description: Read 1 byte of data from addr
253  *			 set by envctrl_i2c_read_addr()
254  * Return : Data from address set by envctrl_i2c_read_addr().
255  */
256 static unsigned char envctrl_i2c_read_data(void)
257 {
258 	envtrl_i2c_test_pin();
259 	writeb(CONTROL_ES0, i2c + PCF8584_CSR);  /* Send neg ack. */
260 	return readb(i2c + PCF8584_DATA);
261 }
262 
263 /* Function Description: Instruct the device which port to read data from.
264  * Return : None.
265  */
266 static void envctrl_i2c_write_data(unsigned char port)
267 {
268 	envtrl_i2c_test_pin();
269 	writeb(port, i2c + PCF8584_DATA);
270 }
271 
272 /* Function Description: Generate Stop condition after last byte is sent.
273  * Return : None.
274  */
275 static void envctrl_i2c_stop(void)
276 {
277 	envtrl_i2c_test_pin();
278 	writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
279 }
280 
281 /* Function Description: Read adc device.
282  * Return : Data at address and port.
283  */
284 static unsigned char envctrl_i2c_read_8591(unsigned char addr, unsigned char port)
285 {
286 	/* Send address. */
287 	envctrl_i2c_write_addr(addr);
288 
289 	/* Setup port to read. */
290 	envctrl_i2c_write_data(port);
291 	envctrl_i2c_stop();
292 
293 	/* Read port. */
294 	envctrl_i2c_read_addr(addr);
295 
296 	/* Do a single byte read and send stop. */
297 	envctrl_i2c_read_data();
298 	envctrl_i2c_stop();
299 
300 	return readb(i2c + PCF8584_DATA);
301 }
302 
303 /* Function Description: Read gpio device.
304  * Return : Data at address.
305  */
306 static unsigned char envctrl_i2c_read_8574(unsigned char addr)
307 {
308 	unsigned char rd;
309 
310 	envctrl_i2c_read_addr(addr);
311 
312 	/* Do a single byte read and send stop. */
313 	rd = envctrl_i2c_read_data();
314 	envctrl_i2c_stop();
315 	return rd;
316 }
317 
318 /* Function Description: Decode data read from an adc device using firmware
319  *                       table.
320  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
321  */
322 static int envctrl_i2c_data_translate(unsigned char data, int translate_type,
323 				      int scale, char *tbl, char *bufdata)
324 {
325 	int len = 0;
326 
327 	switch (translate_type) {
328 	case ENVCTRL_TRANSLATE_NO:
329 		/* No decode necessary. */
330 		len = 1;
331 		bufdata[0] = data;
332 		break;
333 
334 	case ENVCTRL_TRANSLATE_FULL:
335 		/* Decode this way: data = table[data]. */
336 		len = 1;
337 		bufdata[0] = tbl[data];
338 		break;
339 
340 	case ENVCTRL_TRANSLATE_SCALE:
341 		/* Decode this way: data = table[data]/scale */
342 		sprintf(bufdata,"%d ", (tbl[data] * 10) / (scale));
343 		len = strlen(bufdata);
344 		bufdata[len - 1] = bufdata[len - 2];
345 		bufdata[len - 2] = '.';
346 		break;
347 
348 	default:
349 		break;
350 	};
351 
352 	return len;
353 }
354 
355 /* Function Description: Read cpu-related data such as cpu temperature, voltage.
356  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
357  */
358 static int envctrl_read_cpu_info(int cpu, struct i2c_child_t *pchild,
359 				 char mon_type, unsigned char *bufdata)
360 {
361 	unsigned char data;
362 	int i;
363 	char *tbl, j = -1;
364 
365 	/* Find the right monitor type and channel. */
366 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
367 		if (pchild->mon_type[i] == mon_type) {
368 			if (++j == cpu) {
369 				break;
370 			}
371 		}
372 	}
373 
374 	if (j != cpu)
375 		return 0;
376 
377         /* Read data from address and port. */
378 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
379 				     (unsigned char)pchild->chnl_array[i].chnl_no);
380 
381 	/* Find decoding table. */
382 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
383 
384 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
385 					  pchild->tblprop_array[i].scale,
386 					  tbl, bufdata);
387 }
388 
389 /* Function Description: Read noncpu-related data such as motherboard
390  *                       temperature.
391  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
392  */
393 static int envctrl_read_noncpu_info(struct i2c_child_t *pchild,
394 				    char mon_type, unsigned char *bufdata)
395 {
396 	unsigned char data;
397 	int i;
398 	char *tbl = NULL;
399 
400 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
401 		if (pchild->mon_type[i] == mon_type)
402 			break;
403 	}
404 
405 	if (i >= PCF8584_MAX_CHANNELS)
406 		return 0;
407 
408         /* Read data from address and port. */
409 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
410 				     (unsigned char)pchild->chnl_array[i].chnl_no);
411 
412 	/* Find decoding table. */
413 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
414 
415 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
416 					  pchild->tblprop_array[i].scale,
417 					  tbl, bufdata);
418 }
419 
420 /* Function Description: Read fan status.
421  * Return : Always 1 byte. Status stored in bufdata.
422  */
423 static int envctrl_i2c_fan_status(struct i2c_child_t *pchild,
424 				  unsigned char data,
425 				  char *bufdata)
426 {
427 	unsigned char tmp, ret = 0;
428 	int i, j = 0;
429 
430 	tmp = data & pchild->fan_mask;
431 
432 	if (tmp == pchild->fan_mask) {
433 		/* All bits are on. All fans are functioning. */
434 		ret = ENVCTRL_ALL_FANS_GOOD;
435 	} else if (tmp == 0) {
436 		/* No bits are on. No fans are functioning. */
437 		ret = ENVCTRL_ALL_FANS_BAD;
438 	} else {
439 		/* Go through all channels, mark 'on' the matched bits.
440 		 * Notice that fan_mask may have discontiguous bits but
441 		 * return mask are always contiguous. For example if we
442 		 * monitor 4 fans at channels 0,1,2,4, the return mask
443 		 * should be 00010000 if only fan at channel 4 is working.
444 		 */
445 		for (i = 0; i < PCF8584_MAX_CHANNELS;i++) {
446 			if (pchild->fan_mask & chnls_mask[i]) {
447 				if (!(chnls_mask[i] & tmp))
448 					ret |= chnls_mask[j];
449 
450 				j++;
451 			}
452 		}
453 	}
454 
455 	bufdata[0] = ret;
456 	return 1;
457 }
458 
459 /* Function Description: Read global addressing line.
460  * Return : Always 1 byte. Status stored in bufdata.
461  */
462 static int envctrl_i2c_globaladdr(struct i2c_child_t *pchild,
463 				  unsigned char data,
464 				  char *bufdata)
465 {
466 	/* Translatation table is not necessary, as global
467 	 * addr is the integer value of the GA# bits.
468 	 *
469 	 * NOTE: MSB is documented as zero, but I see it as '1' always....
470 	 *
471 	 * -----------------------------------------------
472 	 * | 0 | FAL | DEG | GA4 | GA3 | GA2 | GA1 | GA0 |
473 	 * -----------------------------------------------
474 	 * GA0 - GA4	integer value of Global Address (backplane slot#)
475 	 * DEG			0 = cPCI Power supply output is starting to degrade
476 	 * 				1 = cPCI Power supply output is OK
477 	 * FAL			0 = cPCI Power supply has failed
478 	 * 				1 = cPCI Power supply output is OK
479 	 */
480 	bufdata[0] = (data & ENVCTRL_GLOBALADDR_ADDR_MASK);
481 	return 1;
482 }
483 
484 /* Function Description: Read standard voltage and power supply status.
485  * Return : Always 1 byte. Status stored in bufdata.
486  */
487 static unsigned char envctrl_i2c_voltage_status(struct i2c_child_t *pchild,
488 						unsigned char data,
489 						char *bufdata)
490 {
491 	unsigned char tmp, ret = 0;
492 	int i, j = 0;
493 
494 	tmp = data & pchild->voltage_mask;
495 
496 	/* Two channels are used to monitor voltage and power supply. */
497 	if (tmp == pchild->voltage_mask) {
498 		/* All bits are on. Voltage and power supply are okay. */
499 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_GOOD;
500 	} else if (tmp == 0) {
501 		/* All bits are off. Voltage and power supply are bad */
502 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_BAD;
503 	} else {
504 		/* Either voltage or power supply has problem. */
505 		for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
506 			if (pchild->voltage_mask & chnls_mask[i]) {
507 				j++;
508 
509 				/* Break out when there is a mismatch. */
510 				if (!(chnls_mask[i] & tmp))
511 					break;
512 			}
513 		}
514 
515 		/* Make a wish that hardware will always use the
516 		 * first channel for voltage and the second for
517 		 * power supply.
518 		 */
519 		if (j == 1)
520 			ret = ENVCTRL_VOLTAGE_BAD;
521 		else
522 			ret = ENVCTRL_POWERSUPPLY_BAD;
523 	}
524 
525 	bufdata[0] = ret;
526 	return 1;
527 }
528 
529 /* Function Description: Read a byte from /dev/envctrl. Mapped to user read().
530  * Return: Number of read bytes. 0 for error.
531  */
532 static ssize_t
533 envctrl_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
534 {
535 	struct i2c_child_t *pchild;
536 	unsigned char data[10];
537 	int ret = 0;
538 
539 	/* Get the type of read as decided in ioctl() call.
540 	 * Find the appropriate i2c child.
541 	 * Get the data and put back to the user buffer.
542 	 */
543 
544 	switch ((int)(long)file->private_data) {
545 	case ENVCTRL_RD_WARNING_TEMPERATURE:
546 		if (warning_temperature == 0)
547 			return 0;
548 
549 		data[0] = (unsigned char)(warning_temperature);
550 		ret = 1;
551 		if (copy_to_user(buf, data, ret))
552 			ret = -EFAULT;
553 		break;
554 
555 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
556 		if (shutdown_temperature == 0)
557 			return 0;
558 
559 		data[0] = (unsigned char)(shutdown_temperature);
560 		ret = 1;
561 		if (copy_to_user(buf, data, ret))
562 			ret = -EFAULT;
563 		break;
564 
565 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
566 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_MTHRBDTEMP_MON)))
567 			return 0;
568 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_MTHRBDTEMP_MON, data);
569 		if (copy_to_user(buf, data, ret))
570 			ret = -EFAULT;
571 		break;
572 
573 	case ENVCTRL_RD_CPU_TEMPERATURE:
574 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON)))
575 			return 0;
576 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUTEMP_MON, data);
577 
578 		/* Reset cpu to the default cpu0. */
579 		if (copy_to_user(buf, data, ret))
580 			ret = -EFAULT;
581 		break;
582 
583 	case ENVCTRL_RD_CPU_VOLTAGE:
584 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUVOLTAGE_MON)))
585 			return 0;
586 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUVOLTAGE_MON, data);
587 
588 		/* Reset cpu to the default cpu0. */
589 		if (copy_to_user(buf, data, ret))
590 			ret = -EFAULT;
591 		break;
592 
593 	case ENVCTRL_RD_SCSI_TEMPERATURE:
594 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_SCSITEMP_MON)))
595 			return 0;
596 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_SCSITEMP_MON, data);
597 		if (copy_to_user(buf, data, ret))
598 			ret = -EFAULT;
599 		break;
600 
601 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
602 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_ETHERTEMP_MON)))
603 			return 0;
604 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_ETHERTEMP_MON, data);
605 		if (copy_to_user(buf, data, ret))
606 			ret = -EFAULT;
607 		break;
608 
609 	case ENVCTRL_RD_FAN_STATUS:
610 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_FANSTAT_MON)))
611 			return 0;
612 		data[0] = envctrl_i2c_read_8574(pchild->addr);
613 		ret = envctrl_i2c_fan_status(pchild,data[0], data);
614 		if (copy_to_user(buf, data, ret))
615 			ret = -EFAULT;
616 		break;
617 
618 	case ENVCTRL_RD_GLOBALADDRESS:
619 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
620 			return 0;
621 		data[0] = envctrl_i2c_read_8574(pchild->addr);
622 		ret = envctrl_i2c_globaladdr(pchild, data[0], data);
623 		if (copy_to_user(buf, data, ret))
624 			ret = -EFAULT;
625 		break;
626 
627 	case ENVCTRL_RD_VOLTAGE_STATUS:
628 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_VOLTAGESTAT_MON)))
629 			/* If voltage monitor not present, check for CPCI equivalent */
630 			if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
631 				return 0;
632 		data[0] = envctrl_i2c_read_8574(pchild->addr);
633 		ret = envctrl_i2c_voltage_status(pchild, data[0], data);
634 		if (copy_to_user(buf, data, ret))
635 			ret = -EFAULT;
636 		break;
637 
638 	default:
639 		break;
640 
641 	};
642 
643 	return ret;
644 }
645 
646 /* Function Description: Command what to read.  Mapped to user ioctl().
647  * Return: Gives 0 for implemented commands, -EINVAL otherwise.
648  */
649 static long
650 envctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
651 {
652 	char __user *infobuf;
653 
654 	switch (cmd) {
655 	case ENVCTRL_RD_WARNING_TEMPERATURE:
656 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
657 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
658 	case ENVCTRL_RD_FAN_STATUS:
659 	case ENVCTRL_RD_VOLTAGE_STATUS:
660 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
661 	case ENVCTRL_RD_SCSI_TEMPERATURE:
662 	case ENVCTRL_RD_GLOBALADDRESS:
663 		file->private_data = (void *)(long)cmd;
664 		break;
665 
666 	case ENVCTRL_RD_CPU_TEMPERATURE:
667 	case ENVCTRL_RD_CPU_VOLTAGE:
668 		/* Check to see if application passes in any cpu number,
669 		 * the default is cpu0.
670 		 */
671 		infobuf = (char __user *) arg;
672 		if (infobuf == NULL) {
673 			read_cpu = 0;
674 		}else {
675 			get_user(read_cpu, infobuf);
676 		}
677 
678 		/* Save the command for use when reading. */
679 		file->private_data = (void *)(long)cmd;
680 		break;
681 
682 	default:
683 		return -EINVAL;
684 	};
685 
686 	return 0;
687 }
688 
689 /* Function Description: open device. Mapped to user open().
690  * Return: Always 0.
691  */
692 static int
693 envctrl_open(struct inode *inode, struct file *file)
694 {
695 	file->private_data = NULL;
696 	return 0;
697 }
698 
699 /* Function Description: Open device. Mapped to user close().
700  * Return: Always 0.
701  */
702 static int
703 envctrl_release(struct inode *inode, struct file *file)
704 {
705 	return 0;
706 }
707 
708 static const struct file_operations envctrl_fops = {
709 	.owner =		THIS_MODULE,
710 	.read =			envctrl_read,
711 	.unlocked_ioctl =	envctrl_ioctl,
712 #ifdef CONFIG_COMPAT
713 	.compat_ioctl =		envctrl_ioctl,
714 #endif
715 	.open =			envctrl_open,
716 	.release =		envctrl_release,
717 };
718 
719 static struct miscdevice envctrl_dev = {
720 	ENVCTRL_MINOR,
721 	"envctrl",
722 	&envctrl_fops
723 };
724 
725 /* Function Description: Set monitor type based on firmware description.
726  * Return: None.
727  */
728 static void envctrl_set_mon(struct i2c_child_t *pchild,
729 			    char *chnl_desc,
730 			    int chnl_no)
731 {
732 	/* Firmware only has temperature type.  It does not distinguish
733 	 * different kinds of temperatures.  We use channel description
734 	 * to disinguish them.
735 	 */
736 	if (!(strcmp(chnl_desc,"temp,cpu")) ||
737 	    !(strcmp(chnl_desc,"temp,cpu0")) ||
738 	    !(strcmp(chnl_desc,"temp,cpu1")) ||
739 	    !(strcmp(chnl_desc,"temp,cpu2")) ||
740 	    !(strcmp(chnl_desc,"temp,cpu3")))
741 		pchild->mon_type[chnl_no] = ENVCTRL_CPUTEMP_MON;
742 
743 	if (!(strcmp(chnl_desc,"vddcore,cpu0")) ||
744 	    !(strcmp(chnl_desc,"vddcore,cpu1")) ||
745 	    !(strcmp(chnl_desc,"vddcore,cpu2")) ||
746 	    !(strcmp(chnl_desc,"vddcore,cpu3")))
747 		pchild->mon_type[chnl_no] = ENVCTRL_CPUVOLTAGE_MON;
748 
749 	if (!(strcmp(chnl_desc,"temp,motherboard")))
750 		pchild->mon_type[chnl_no] = ENVCTRL_MTHRBDTEMP_MON;
751 
752 	if (!(strcmp(chnl_desc,"temp,scsi")))
753 		pchild->mon_type[chnl_no] = ENVCTRL_SCSITEMP_MON;
754 
755 	if (!(strcmp(chnl_desc,"temp,ethernet")))
756 		pchild->mon_type[chnl_no] = ENVCTRL_ETHERTEMP_MON;
757 }
758 
759 /* Function Description: Initialize monitor channel with channel desc,
760  *                       decoding tables, monitor type, optional properties.
761  * Return: None.
762  */
763 static void envctrl_init_adc(struct i2c_child_t *pchild, struct device_node *dp)
764 {
765 	int i = 0, len;
766 	char *pos;
767 	unsigned int *pval;
768 
769 	/* Firmware describe channels into a stream separated by a '\0'. */
770 	pos = of_get_property(dp, "channels-description", &len);
771 
772 	while (len > 0) {
773 		int l = strlen(pos) + 1;
774 		envctrl_set_mon(pchild, pos, i++);
775 		len -= l;
776 		pos += l;
777 	}
778 
779 	/* Get optional properties. */
780 	pval = of_get_property(dp, "warning-temp", NULL);
781 	if (pval)
782 		warning_temperature = *pval;
783 
784 	pval = of_get_property(dp, "shutdown-temp", NULL);
785 	if (pval)
786 		shutdown_temperature = *pval;
787 }
788 
789 /* Function Description: Initialize child device monitoring fan status.
790  * Return: None.
791  */
792 static void envctrl_init_fanstat(struct i2c_child_t *pchild)
793 {
794 	int i;
795 
796 	/* Go through all channels and set up the mask. */
797 	for (i = 0; i < pchild->total_chnls; i++)
798 		pchild->fan_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
799 
800 	/* We only need to know if this child has fan status monitored.
801 	 * We don't care which channels since we have the mask already.
802 	 */
803 	pchild->mon_type[0] = ENVCTRL_FANSTAT_MON;
804 }
805 
806 /* Function Description: Initialize child device for global addressing line.
807  * Return: None.
808  */
809 static void envctrl_init_globaladdr(struct i2c_child_t *pchild)
810 {
811 	int i;
812 
813 	/* Voltage/PowerSupply monitoring is piggybacked
814 	 * with Global Address on CompactPCI.  See comments
815 	 * within envctrl_i2c_globaladdr for bit assignments.
816 	 *
817 	 * The mask is created here by assigning mask bits to each
818 	 * bit position that represents PCF8584_VOLTAGE_TYPE data.
819 	 * Channel numbers are not consecutive within the globaladdr
820 	 * node (why?), so we use the actual counter value as chnls_mask
821 	 * index instead of the chnl_array[x].chnl_no value.
822 	 *
823 	 * NOTE: This loop could be replaced with a constant representing
824 	 * a mask of bits 5&6 (ENVCTRL_GLOBALADDR_PSTAT_MASK).
825 	 */
826 	for (i = 0; i < pchild->total_chnls; i++) {
827 		if (PCF8584_VOLTAGE_TYPE == pchild->chnl_array[i].type) {
828 			pchild->voltage_mask |= chnls_mask[i];
829 		}
830 	}
831 
832 	/* We only need to know if this child has global addressing
833 	 * line monitored.  We don't care which channels since we know
834 	 * the mask already (ENVCTRL_GLOBALADDR_ADDR_MASK).
835 	 */
836 	pchild->mon_type[0] = ENVCTRL_GLOBALADDR_MON;
837 }
838 
839 /* Initialize child device monitoring voltage status. */
840 static void envctrl_init_voltage_status(struct i2c_child_t *pchild)
841 {
842 	int i;
843 
844 	/* Go through all channels and set up the mask. */
845 	for (i = 0; i < pchild->total_chnls; i++)
846 		pchild->voltage_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
847 
848 	/* We only need to know if this child has voltage status monitored.
849 	 * We don't care which channels since we have the mask already.
850 	 */
851 	pchild->mon_type[0] = ENVCTRL_VOLTAGESTAT_MON;
852 }
853 
854 /* Function Description: Initialize i2c child device.
855  * Return: None.
856  */
857 static void envctrl_init_i2c_child(struct linux_ebus_child *edev_child,
858 				   struct i2c_child_t *pchild)
859 {
860 	int len, i, tbls_size = 0;
861 	struct device_node *dp = edev_child->prom_node;
862 	void *pval;
863 
864 	/* Get device address. */
865 	pval = of_get_property(dp, "reg", &len);
866 	memcpy(&pchild->addr, pval, len);
867 
868 	/* Get tables property.  Read firmware temperature tables. */
869 	pval = of_get_property(dp, "translation", &len);
870 	if (pval && len > 0) {
871 		memcpy(pchild->tblprop_array, pval, len);
872                 pchild->total_tbls = len / sizeof(struct pcf8584_tblprop);
873 		for (i = 0; i < pchild->total_tbls; i++) {
874 			if ((pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset) > tbls_size) {
875 				tbls_size = pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset;
876 			}
877 		}
878 
879                 pchild->tables = kmalloc(tbls_size, GFP_KERNEL);
880 		if (pchild->tables == NULL){
881 			printk("envctrl: Failed to allocate table.\n");
882 			return;
883 		}
884 		pval = of_get_property(dp, "tables", &len);
885                 if (!pval || len <= 0) {
886 			printk("envctrl: Failed to get table.\n");
887 			return;
888 		}
889 		memcpy(pchild->tables, pval, len);
890 	}
891 
892 	/* SPARCengine ASM Reference Manual (ref. SMI doc 805-7581-04)
893 	 * sections 2.5, 3.5, 4.5 state node 0x70 for CP1400/1500 is
894 	 * "For Factory Use Only."
895 	 *
896 	 * We ignore the node on these platforms by assigning the
897 	 * 'NULL' monitor type.
898 	 */
899 	if (ENVCTRL_CPCI_IGNORED_NODE == pchild->addr) {
900 		struct device_node *root_node;
901 		int len;
902 
903 		root_node = of_find_node_by_path("/");
904 		if (!strcmp(root_node->name, "SUNW,UltraSPARC-IIi-cEngine")) {
905 			for (len = 0; len < PCF8584_MAX_CHANNELS; ++len) {
906 				pchild->mon_type[len] = ENVCTRL_NOMON;
907 			}
908 			return;
909 		}
910 	}
911 
912 	/* Get the monitor channels. */
913 	pval = of_get_property(dp, "channels-in-use", &len);
914 	memcpy(pchild->chnl_array, pval, len);
915 	pchild->total_chnls = len / sizeof(struct pcf8584_channel);
916 
917 	for (i = 0; i < pchild->total_chnls; i++) {
918 		switch (pchild->chnl_array[i].type) {
919 		case PCF8584_TEMP_TYPE:
920 			envctrl_init_adc(pchild, dp);
921 			break;
922 
923 		case PCF8584_GLOBALADDR_TYPE:
924 			envctrl_init_globaladdr(pchild);
925 			i = pchild->total_chnls;
926 			break;
927 
928 		case PCF8584_FANSTAT_TYPE:
929 			envctrl_init_fanstat(pchild);
930 			i = pchild->total_chnls;
931 			break;
932 
933 		case PCF8584_VOLTAGE_TYPE:
934 			if (pchild->i2ctype == I2C_ADC) {
935 				envctrl_init_adc(pchild,dp);
936 			} else {
937 				envctrl_init_voltage_status(pchild);
938 			}
939 			i = pchild->total_chnls;
940 			break;
941 
942 		default:
943 			break;
944 		};
945 	}
946 }
947 
948 /* Function Description: Search the child device list for a device.
949  * Return : The i2c child if found. NULL otherwise.
950  */
951 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
952 {
953 	int i, j;
954 
955 	for (i = 0; i < ENVCTRL_MAX_CPU*2; i++) {
956 		for (j = 0; j < PCF8584_MAX_CHANNELS; j++) {
957 			if (i2c_childlist[i].mon_type[j] == mon_type) {
958 				return (struct i2c_child_t *)(&(i2c_childlist[i]));
959 			}
960 		}
961 	}
962 	return NULL;
963 }
964 
965 static void envctrl_do_shutdown(void)
966 {
967 	static int inprog = 0;
968 	static char *envp[] = {
969 		"HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
970 	char *argv[] = {
971 		"/sbin/shutdown", "-h", "now", NULL };
972 	int ret;
973 
974 	if (inprog != 0)
975 		return;
976 
977 	inprog = 1;
978 	printk(KERN_CRIT "kenvctrld: WARNING: Shutting down the system now.\n");
979 	ret = call_usermodehelper("/sbin/shutdown", argv, envp, 0);
980 	if (ret < 0) {
981 		printk(KERN_CRIT "kenvctrld: WARNING: system shutdown failed!\n");
982 		inprog = 0;  /* unlikely to succeed, but we could try again */
983 	}
984 }
985 
986 static struct task_struct *kenvctrld_task;
987 
988 static int kenvctrld(void *__unused)
989 {
990 	int poll_interval;
991 	int whichcpu;
992 	char tempbuf[10];
993 	struct i2c_child_t *cputemp;
994 
995 	if (NULL == (cputemp = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON))) {
996 		printk(KERN_ERR
997 		       "envctrl: kenvctrld unable to monitor CPU temp-- exiting\n");
998 		return -ENODEV;
999 	}
1000 
1001 	poll_interval = 5000; /* TODO env_mon_interval */
1002 
1003 	printk(KERN_INFO "envctrl: %s starting...\n", current->comm);
1004 	for (;;) {
1005 		msleep_interruptible(poll_interval);
1006 
1007 		if (kthread_should_stop())
1008 			break;
1009 
1010 		for (whichcpu = 0; whichcpu < ENVCTRL_MAX_CPU; ++whichcpu) {
1011 			if (0 < envctrl_read_cpu_info(whichcpu, cputemp,
1012 						      ENVCTRL_CPUTEMP_MON,
1013 						      tempbuf)) {
1014 				if (tempbuf[0] >= shutdown_temperature) {
1015 					printk(KERN_CRIT
1016 						"%s: WARNING: CPU%i temperature %i C meets or exceeds "\
1017 						"shutdown threshold %i C\n",
1018 						current->comm, whichcpu,
1019 						tempbuf[0], shutdown_temperature);
1020 					envctrl_do_shutdown();
1021 				}
1022 			}
1023 		}
1024 	}
1025 	printk(KERN_INFO "envctrl: %s exiting...\n", current->comm);
1026 	return 0;
1027 }
1028 
1029 static int __init envctrl_init(void)
1030 {
1031 	struct linux_ebus *ebus = NULL;
1032 	struct linux_ebus_device *edev = NULL;
1033 	struct linux_ebus_child *edev_child = NULL;
1034 	int err, i = 0;
1035 
1036 	for_each_ebus(ebus) {
1037 		for_each_ebusdev(edev, ebus) {
1038 			if (!strcmp(edev->prom_node->name, "bbc")) {
1039 				/* If we find a boot-bus controller node,
1040 				 * then this envctrl driver is not for us.
1041 				 */
1042 				return -ENODEV;
1043 			}
1044 		}
1045 	}
1046 
1047 	/* Traverse through ebus and ebus device list for i2c device and
1048 	 * adc and gpio nodes.
1049 	 */
1050 	for_each_ebus(ebus) {
1051 		for_each_ebusdev(edev, ebus) {
1052 			if (!strcmp(edev->prom_node->name, "i2c")) {
1053 				i2c = ioremap(edev->resource[0].start, 0x2);
1054 				for_each_edevchild(edev, edev_child) {
1055 					if (!strcmp("gpio", edev_child->prom_node->name)) {
1056 						i2c_childlist[i].i2ctype = I2C_GPIO;
1057 						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
1058 					}
1059 					if (!strcmp("adc", edev_child->prom_node->name)) {
1060 						i2c_childlist[i].i2ctype = I2C_ADC;
1061 						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
1062 					}
1063 				}
1064 				goto done;
1065 			}
1066 		}
1067 	}
1068 
1069 done:
1070 	if (!edev) {
1071 		printk("envctrl: I2C device not found.\n");
1072 		return -ENODEV;
1073 	}
1074 
1075 	/* Set device address. */
1076 	writeb(CONTROL_PIN, i2c + PCF8584_CSR);
1077 	writeb(PCF8584_ADDRESS, i2c + PCF8584_DATA);
1078 
1079 	/* Set system clock and SCL frequencies. */
1080 	writeb(CONTROL_PIN | CONTROL_ES1, i2c + PCF8584_CSR);
1081 	writeb(CLK_4_43 | BUS_CLK_90, i2c + PCF8584_DATA);
1082 
1083 	/* Enable serial interface. */
1084 	writeb(CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK, i2c + PCF8584_CSR);
1085 	udelay(200);
1086 
1087 	/* Register the device as a minor miscellaneous device. */
1088 	err = misc_register(&envctrl_dev);
1089 	if (err) {
1090 		printk("envctrl: Unable to get misc minor %d\n",
1091 		       envctrl_dev.minor);
1092 		goto out_iounmap;
1093 	}
1094 
1095 	/* Note above traversal routine post-incremented 'i' to accommodate
1096 	 * a next child device, so we decrement before reverse-traversal of
1097 	 * child devices.
1098 	 */
1099 	printk("envctrl: initialized ");
1100 	for (--i; i >= 0; --i) {
1101 		printk("[%s 0x%lx]%s",
1102 			(I2C_ADC == i2c_childlist[i].i2ctype) ? ("adc") :
1103 			((I2C_GPIO == i2c_childlist[i].i2ctype) ? ("gpio") : ("unknown")),
1104 			i2c_childlist[i].addr, (0 == i) ? ("\n") : (" "));
1105 	}
1106 
1107 	kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
1108 	if (IS_ERR(kenvctrld_task)) {
1109 		err = PTR_ERR(kenvctrld_task);
1110 		goto out_deregister;
1111 	}
1112 
1113 	return 0;
1114 
1115 out_deregister:
1116 	misc_deregister(&envctrl_dev);
1117 out_iounmap:
1118 	iounmap(i2c);
1119 	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++)
1120 		kfree(i2c_childlist[i].tables);
1121 
1122 	return err;
1123 }
1124 
1125 static void __exit envctrl_cleanup(void)
1126 {
1127 	int i;
1128 
1129 	kthread_stop(kenvctrld_task);
1130 
1131 	iounmap(i2c);
1132 	misc_deregister(&envctrl_dev);
1133 
1134 	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++)
1135 		kfree(i2c_childlist[i].tables);
1136 }
1137 
1138 module_init(envctrl_init);
1139 module_exit(envctrl_cleanup);
1140 MODULE_LICENSE("GPL");
1141