xref: /linux/drivers/sbus/char/envctrl.c (revision a17627ef8833ac30622a7b39b7be390e1b174405)
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 #include <asm/io.h>
34 
35 #define ENVCTRL_MINOR	162
36 
37 #define PCF8584_ADDRESS	0x55
38 
39 #define CONTROL_PIN	0x80
40 #define CONTROL_ES0	0x40
41 #define CONTROL_ES1	0x20
42 #define CONTROL_ES2	0x10
43 #define CONTROL_ENI	0x08
44 #define CONTROL_STA	0x04
45 #define CONTROL_STO	0x02
46 #define CONTROL_ACK	0x01
47 
48 #define STATUS_PIN	0x80
49 #define STATUS_STS	0x20
50 #define STATUS_BER	0x10
51 #define STATUS_LRB	0x08
52 #define STATUS_AD0	0x08
53 #define STATUS_AAB	0x04
54 #define STATUS_LAB	0x02
55 #define STATUS_BB	0x01
56 
57 /*
58  * CLK Mode Register.
59  */
60 #define BUS_CLK_90	0x00
61 #define BUS_CLK_45	0x01
62 #define BUS_CLK_11	0x02
63 #define BUS_CLK_1_5	0x03
64 
65 #define CLK_3		0x00
66 #define CLK_4_43	0x10
67 #define CLK_6		0x14
68 #define CLK_8		0x18
69 #define CLK_12		0x1c
70 
71 #define OBD_SEND_START	0xc5    /* value to generate I2c_bus START condition */
72 #define OBD_SEND_STOP 	0xc3    /* value to generate I2c_bus STOP condition */
73 
74 /* Monitor type of i2c child device.
75  * Firmware definitions.
76  */
77 #define PCF8584_MAX_CHANNELS            8
78 #define PCF8584_GLOBALADDR_TYPE			6  /* global address monitor */
79 #define PCF8584_FANSTAT_TYPE            3  /* fan status monitor */
80 #define PCF8584_VOLTAGE_TYPE            2  /* voltage monitor    */
81 #define PCF8584_TEMP_TYPE	        	1  /* temperature monitor*/
82 
83 /* Monitor type of i2c child device.
84  * Driver definitions.
85  */
86 #define ENVCTRL_NOMON				0
87 #define ENVCTRL_CPUTEMP_MON			1    /* cpu temperature monitor */
88 #define ENVCTRL_CPUVOLTAGE_MON	  	2    /* voltage monitor         */
89 #define ENVCTRL_FANSTAT_MON  		3    /* fan status monitor      */
90 #define ENVCTRL_ETHERTEMP_MON		4    /* ethernet temperarture */
91 					     /* monitor                     */
92 #define ENVCTRL_VOLTAGESTAT_MON	  	5    /* voltage status monitor  */
93 #define ENVCTRL_MTHRBDTEMP_MON		6    /* motherboard temperature */
94 #define ENVCTRL_SCSITEMP_MON		7    /* scsi temperarture */
95 #define ENVCTRL_GLOBALADDR_MON		8    /* global address */
96 
97 /* Child device type.
98  * Driver definitions.
99  */
100 #define I2C_ADC				0    /* pcf8591 */
101 #define I2C_GPIO			1    /* pcf8571 */
102 
103 /* Data read from child device may need to decode
104  * through a data table and a scale.
105  * Translation type as defined by firmware.
106  */
107 #define ENVCTRL_TRANSLATE_NO		0
108 #define ENVCTRL_TRANSLATE_PARTIAL	1
109 #define ENVCTRL_TRANSLATE_COMBINED	2
110 #define ENVCTRL_TRANSLATE_FULL		3     /* table[data] */
111 #define ENVCTRL_TRANSLATE_SCALE		4     /* table[data]/scale */
112 
113 /* Driver miscellaneous definitions. */
114 #define ENVCTRL_MAX_CPU			4
115 #define CHANNEL_DESC_SZ			256
116 
117 /* Mask values for combined GlobalAddress/PowerStatus node */
118 #define ENVCTRL_GLOBALADDR_ADDR_MASK 	0x1F
119 #define ENVCTRL_GLOBALADDR_PSTAT_MASK	0x60
120 
121 /* Node 0x70 ignored on CompactPCI CP1400/1500 platforms
122  * (see envctrl_init_i2c_child)
123  */
124 #define ENVCTRL_CPCI_IGNORED_NODE		0x70
125 
126 #define PCF8584_DATA	0x00
127 #define PCF8584_CSR	0x01
128 
129 /* Each child device can be monitored by up to PCF8584_MAX_CHANNELS.
130  * Property of a port or channel as defined by the firmware.
131  */
132 struct pcf8584_channel {
133         unsigned char chnl_no;
134         unsigned char io_direction;
135         unsigned char type;
136         unsigned char last;
137 };
138 
139 /* Each child device may have one or more tables of bytes to help decode
140  * data. Table property as defined by the firmware.
141  */
142 struct pcf8584_tblprop {
143         unsigned int type;
144         unsigned int scale;
145         unsigned int offset; /* offset from the beginning of the table */
146         unsigned int size;
147 };
148 
149 /* i2c child */
150 struct i2c_child_t {
151 	/* Either ADC or GPIO. */
152 	unsigned char i2ctype;
153         unsigned long addr;
154         struct pcf8584_channel chnl_array[PCF8584_MAX_CHANNELS];
155 
156 	/* Channel info. */
157 	unsigned int total_chnls;	/* Number of monitor channels. */
158 	unsigned char fan_mask;		/* Byte mask for fan status channels. */
159 	unsigned char voltage_mask;	/* Byte mask for voltage status channels. */
160         struct pcf8584_tblprop tblprop_array[PCF8584_MAX_CHANNELS];
161 
162 	/* Properties of all monitor channels. */
163 	unsigned int total_tbls;	/* Number of monitor tables. */
164         char *tables;			/* Pointer to table(s). */
165 	char chnls_desc[CHANNEL_DESC_SZ]; /* Channel description. */
166 	char mon_type[PCF8584_MAX_CHANNELS];
167 };
168 
169 static void __iomem *i2c;
170 static struct i2c_child_t i2c_childlist[ENVCTRL_MAX_CPU*2];
171 static unsigned char chnls_mask[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
172 static unsigned int warning_temperature = 0;
173 static unsigned int shutdown_temperature = 0;
174 static char read_cpu;
175 
176 /* Forward declarations. */
177 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char);
178 
179 /* Function Description: Test the PIN bit (Pending Interrupt Not)
180  * 			 to test when serial transmission is completed .
181  * Return : None.
182  */
183 static void envtrl_i2c_test_pin(void)
184 {
185 	int limit = 1000000;
186 
187 	while (--limit > 0) {
188 		if (!(readb(i2c + PCF8584_CSR) & STATUS_PIN))
189 			break;
190 		udelay(1);
191 	}
192 
193 	if (limit <= 0)
194 		printk(KERN_INFO "envctrl: Pin status will not clear.\n");
195 }
196 
197 /* Function Description: Test busy bit.
198  * Return : None.
199  */
200 static void envctrl_i2c_test_bb(void)
201 {
202 	int limit = 1000000;
203 
204 	while (--limit > 0) {
205 		/* Busy bit 0 means busy. */
206 		if (readb(i2c + PCF8584_CSR) & STATUS_BB)
207 			break;
208 		udelay(1);
209 	}
210 
211 	if (limit <= 0)
212 		printk(KERN_INFO "envctrl: Busy bit will not clear.\n");
213 }
214 
215 /* Function Description: Send the address for a read access.
216  * Return : 0 if not acknowledged, otherwise acknowledged.
217  */
218 static int envctrl_i2c_read_addr(unsigned char addr)
219 {
220 	envctrl_i2c_test_bb();
221 
222 	/* Load address. */
223 	writeb(addr + 1, i2c + PCF8584_DATA);
224 
225 	envctrl_i2c_test_bb();
226 
227 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
228 
229 	/* Wait for PIN. */
230 	envtrl_i2c_test_pin();
231 
232 	/* CSR 0 means acknowledged. */
233 	if (!(readb(i2c + PCF8584_CSR) & STATUS_LRB)) {
234 		return readb(i2c + PCF8584_DATA);
235 	} else {
236 		writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
237 		return 0;
238 	}
239 }
240 
241 /* Function Description: Send the address for write mode.
242  * Return : None.
243  */
244 static void envctrl_i2c_write_addr(unsigned char addr)
245 {
246 	envctrl_i2c_test_bb();
247 	writeb(addr, i2c + PCF8584_DATA);
248 
249 	/* Generate Start condition. */
250 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
251 }
252 
253 /* Function Description: Read 1 byte of data from addr
254  *			 set by envctrl_i2c_read_addr()
255  * Return : Data from address set by envctrl_i2c_read_addr().
256  */
257 static unsigned char envctrl_i2c_read_data(void)
258 {
259 	envtrl_i2c_test_pin();
260 	writeb(CONTROL_ES0, i2c + PCF8584_CSR);  /* Send neg ack. */
261 	return readb(i2c + PCF8584_DATA);
262 }
263 
264 /* Function Description: Instruct the device which port to read data from.
265  * Return : None.
266  */
267 static void envctrl_i2c_write_data(unsigned char port)
268 {
269 	envtrl_i2c_test_pin();
270 	writeb(port, i2c + PCF8584_DATA);
271 }
272 
273 /* Function Description: Generate Stop condition after last byte is sent.
274  * Return : None.
275  */
276 static void envctrl_i2c_stop(void)
277 {
278 	envtrl_i2c_test_pin();
279 	writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
280 }
281 
282 /* Function Description: Read adc device.
283  * Return : Data at address and port.
284  */
285 static unsigned char envctrl_i2c_read_8591(unsigned char addr, unsigned char port)
286 {
287 	/* Send address. */
288 	envctrl_i2c_write_addr(addr);
289 
290 	/* Setup port to read. */
291 	envctrl_i2c_write_data(port);
292 	envctrl_i2c_stop();
293 
294 	/* Read port. */
295 	envctrl_i2c_read_addr(addr);
296 
297 	/* Do a single byte read and send stop. */
298 	envctrl_i2c_read_data();
299 	envctrl_i2c_stop();
300 
301 	return readb(i2c + PCF8584_DATA);
302 }
303 
304 /* Function Description: Read gpio device.
305  * Return : Data at address.
306  */
307 static unsigned char envctrl_i2c_read_8574(unsigned char addr)
308 {
309 	unsigned char rd;
310 
311 	envctrl_i2c_read_addr(addr);
312 
313 	/* Do a single byte read and send stop. */
314 	rd = envctrl_i2c_read_data();
315 	envctrl_i2c_stop();
316 	return rd;
317 }
318 
319 /* Function Description: Decode data read from an adc device using firmware
320  *                       table.
321  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
322  */
323 static int envctrl_i2c_data_translate(unsigned char data, int translate_type,
324 				      int scale, char *tbl, char *bufdata)
325 {
326 	int len = 0;
327 
328 	switch (translate_type) {
329 	case ENVCTRL_TRANSLATE_NO:
330 		/* No decode necessary. */
331 		len = 1;
332 		bufdata[0] = data;
333 		break;
334 
335 	case ENVCTRL_TRANSLATE_FULL:
336 		/* Decode this way: data = table[data]. */
337 		len = 1;
338 		bufdata[0] = tbl[data];
339 		break;
340 
341 	case ENVCTRL_TRANSLATE_SCALE:
342 		/* Decode this way: data = table[data]/scale */
343 		sprintf(bufdata,"%d ", (tbl[data] * 10) / (scale));
344 		len = strlen(bufdata);
345 		bufdata[len - 1] = bufdata[len - 2];
346 		bufdata[len - 2] = '.';
347 		break;
348 
349 	default:
350 		break;
351 	};
352 
353 	return len;
354 }
355 
356 /* Function Description: Read cpu-related data such as cpu temperature, voltage.
357  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
358  */
359 static int envctrl_read_cpu_info(int cpu, struct i2c_child_t *pchild,
360 				 char mon_type, unsigned char *bufdata)
361 {
362 	unsigned char data;
363 	int i;
364 	char *tbl, j = -1;
365 
366 	/* Find the right monitor type and channel. */
367 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
368 		if (pchild->mon_type[i] == mon_type) {
369 			if (++j == cpu) {
370 				break;
371 			}
372 		}
373 	}
374 
375 	if (j != cpu)
376 		return 0;
377 
378         /* Read data from address and port. */
379 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
380 				     (unsigned char)pchild->chnl_array[i].chnl_no);
381 
382 	/* Find decoding table. */
383 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
384 
385 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
386 					  pchild->tblprop_array[i].scale,
387 					  tbl, bufdata);
388 }
389 
390 /* Function Description: Read noncpu-related data such as motherboard
391  *                       temperature.
392  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
393  */
394 static int envctrl_read_noncpu_info(struct i2c_child_t *pchild,
395 				    char mon_type, unsigned char *bufdata)
396 {
397 	unsigned char data;
398 	int i;
399 	char *tbl = NULL;
400 
401 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
402 		if (pchild->mon_type[i] == mon_type)
403 			break;
404 	}
405 
406 	if (i >= PCF8584_MAX_CHANNELS)
407 		return 0;
408 
409         /* Read data from address and port. */
410 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
411 				     (unsigned char)pchild->chnl_array[i].chnl_no);
412 
413 	/* Find decoding table. */
414 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
415 
416 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
417 					  pchild->tblprop_array[i].scale,
418 					  tbl, bufdata);
419 }
420 
421 /* Function Description: Read fan status.
422  * Return : Always 1 byte. Status stored in bufdata.
423  */
424 static int envctrl_i2c_fan_status(struct i2c_child_t *pchild,
425 				  unsigned char data,
426 				  char *bufdata)
427 {
428 	unsigned char tmp, ret = 0;
429 	int i, j = 0;
430 
431 	tmp = data & pchild->fan_mask;
432 
433 	if (tmp == pchild->fan_mask) {
434 		/* All bits are on. All fans are functioning. */
435 		ret = ENVCTRL_ALL_FANS_GOOD;
436 	} else if (tmp == 0) {
437 		/* No bits are on. No fans are functioning. */
438 		ret = ENVCTRL_ALL_FANS_BAD;
439 	} else {
440 		/* Go through all channels, mark 'on' the matched bits.
441 		 * Notice that fan_mask may have discontiguous bits but
442 		 * return mask are always contiguous. For example if we
443 		 * monitor 4 fans at channels 0,1,2,4, the return mask
444 		 * should be 00010000 if only fan at channel 4 is working.
445 		 */
446 		for (i = 0; i < PCF8584_MAX_CHANNELS;i++) {
447 			if (pchild->fan_mask & chnls_mask[i]) {
448 				if (!(chnls_mask[i] & tmp))
449 					ret |= chnls_mask[j];
450 
451 				j++;
452 			}
453 		}
454 	}
455 
456 	bufdata[0] = ret;
457 	return 1;
458 }
459 
460 /* Function Description: Read global addressing line.
461  * Return : Always 1 byte. Status stored in bufdata.
462  */
463 static int envctrl_i2c_globaladdr(struct i2c_child_t *pchild,
464 				  unsigned char data,
465 				  char *bufdata)
466 {
467 	/* Translatation table is not necessary, as global
468 	 * addr is the integer value of the GA# bits.
469 	 *
470 	 * NOTE: MSB is documented as zero, but I see it as '1' always....
471 	 *
472 	 * -----------------------------------------------
473 	 * | 0 | FAL | DEG | GA4 | GA3 | GA2 | GA1 | GA0 |
474 	 * -----------------------------------------------
475 	 * GA0 - GA4	integer value of Global Address (backplane slot#)
476 	 * DEG			0 = cPCI Power supply output is starting to degrade
477 	 * 				1 = cPCI Power supply output is OK
478 	 * FAL			0 = cPCI Power supply has failed
479 	 * 				1 = cPCI Power supply output is OK
480 	 */
481 	bufdata[0] = (data & ENVCTRL_GLOBALADDR_ADDR_MASK);
482 	return 1;
483 }
484 
485 /* Function Description: Read standard voltage and power supply status.
486  * Return : Always 1 byte. Status stored in bufdata.
487  */
488 static unsigned char envctrl_i2c_voltage_status(struct i2c_child_t *pchild,
489 						unsigned char data,
490 						char *bufdata)
491 {
492 	unsigned char tmp, ret = 0;
493 	int i, j = 0;
494 
495 	tmp = data & pchild->voltage_mask;
496 
497 	/* Two channels are used to monitor voltage and power supply. */
498 	if (tmp == pchild->voltage_mask) {
499 		/* All bits are on. Voltage and power supply are okay. */
500 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_GOOD;
501 	} else if (tmp == 0) {
502 		/* All bits are off. Voltage and power supply are bad */
503 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_BAD;
504 	} else {
505 		/* Either voltage or power supply has problem. */
506 		for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
507 			if (pchild->voltage_mask & chnls_mask[i]) {
508 				j++;
509 
510 				/* Break out when there is a mismatch. */
511 				if (!(chnls_mask[i] & tmp))
512 					break;
513 			}
514 		}
515 
516 		/* Make a wish that hardware will always use the
517 		 * first channel for voltage and the second for
518 		 * power supply.
519 		 */
520 		if (j == 1)
521 			ret = ENVCTRL_VOLTAGE_BAD;
522 		else
523 			ret = ENVCTRL_POWERSUPPLY_BAD;
524 	}
525 
526 	bufdata[0] = ret;
527 	return 1;
528 }
529 
530 /* Function Description: Read a byte from /dev/envctrl. Mapped to user read().
531  * Return: Number of read bytes. 0 for error.
532  */
533 static ssize_t
534 envctrl_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
535 {
536 	struct i2c_child_t *pchild;
537 	unsigned char data[10];
538 	int ret = 0;
539 
540 	/* Get the type of read as decided in ioctl() call.
541 	 * Find the appropriate i2c child.
542 	 * Get the data and put back to the user buffer.
543 	 */
544 
545 	switch ((int)(long)file->private_data) {
546 	case ENVCTRL_RD_WARNING_TEMPERATURE:
547 		if (warning_temperature == 0)
548 			return 0;
549 
550 		data[0] = (unsigned char)(warning_temperature);
551 		ret = 1;
552 		if (copy_to_user(buf, data, ret))
553 			ret = -EFAULT;
554 		break;
555 
556 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
557 		if (shutdown_temperature == 0)
558 			return 0;
559 
560 		data[0] = (unsigned char)(shutdown_temperature);
561 		ret = 1;
562 		if (copy_to_user(buf, data, ret))
563 			ret = -EFAULT;
564 		break;
565 
566 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
567 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_MTHRBDTEMP_MON)))
568 			return 0;
569 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_MTHRBDTEMP_MON, data);
570 		if (copy_to_user(buf, data, ret))
571 			ret = -EFAULT;
572 		break;
573 
574 	case ENVCTRL_RD_CPU_TEMPERATURE:
575 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON)))
576 			return 0;
577 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUTEMP_MON, data);
578 
579 		/* Reset cpu to the default cpu0. */
580 		if (copy_to_user(buf, data, ret))
581 			ret = -EFAULT;
582 		break;
583 
584 	case ENVCTRL_RD_CPU_VOLTAGE:
585 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUVOLTAGE_MON)))
586 			return 0;
587 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUVOLTAGE_MON, data);
588 
589 		/* Reset cpu to the default cpu0. */
590 		if (copy_to_user(buf, data, ret))
591 			ret = -EFAULT;
592 		break;
593 
594 	case ENVCTRL_RD_SCSI_TEMPERATURE:
595 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_SCSITEMP_MON)))
596 			return 0;
597 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_SCSITEMP_MON, data);
598 		if (copy_to_user(buf, data, ret))
599 			ret = -EFAULT;
600 		break;
601 
602 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
603 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_ETHERTEMP_MON)))
604 			return 0;
605 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_ETHERTEMP_MON, data);
606 		if (copy_to_user(buf, data, ret))
607 			ret = -EFAULT;
608 		break;
609 
610 	case ENVCTRL_RD_FAN_STATUS:
611 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_FANSTAT_MON)))
612 			return 0;
613 		data[0] = envctrl_i2c_read_8574(pchild->addr);
614 		ret = envctrl_i2c_fan_status(pchild,data[0], data);
615 		if (copy_to_user(buf, data, ret))
616 			ret = -EFAULT;
617 		break;
618 
619 	case ENVCTRL_RD_GLOBALADDRESS:
620 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
621 			return 0;
622 		data[0] = envctrl_i2c_read_8574(pchild->addr);
623 		ret = envctrl_i2c_globaladdr(pchild, data[0], data);
624 		if (copy_to_user(buf, data, ret))
625 			ret = -EFAULT;
626 		break;
627 
628 	case ENVCTRL_RD_VOLTAGE_STATUS:
629 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_VOLTAGESTAT_MON)))
630 			/* If voltage monitor not present, check for CPCI equivalent */
631 			if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
632 				return 0;
633 		data[0] = envctrl_i2c_read_8574(pchild->addr);
634 		ret = envctrl_i2c_voltage_status(pchild, data[0], data);
635 		if (copy_to_user(buf, data, ret))
636 			ret = -EFAULT;
637 		break;
638 
639 	default:
640 		break;
641 
642 	};
643 
644 	return ret;
645 }
646 
647 /* Function Description: Command what to read.  Mapped to user ioctl().
648  * Return: Gives 0 for implemented commands, -EINVAL otherwise.
649  */
650 static long
651 envctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
652 {
653 	char __user *infobuf;
654 
655 	switch (cmd) {
656 	case ENVCTRL_RD_WARNING_TEMPERATURE:
657 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
658 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
659 	case ENVCTRL_RD_FAN_STATUS:
660 	case ENVCTRL_RD_VOLTAGE_STATUS:
661 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
662 	case ENVCTRL_RD_SCSI_TEMPERATURE:
663 	case ENVCTRL_RD_GLOBALADDRESS:
664 		file->private_data = (void *)(long)cmd;
665 		break;
666 
667 	case ENVCTRL_RD_CPU_TEMPERATURE:
668 	case ENVCTRL_RD_CPU_VOLTAGE:
669 		/* Check to see if application passes in any cpu number,
670 		 * the default is cpu0.
671 		 */
672 		infobuf = (char __user *) arg;
673 		if (infobuf == NULL) {
674 			read_cpu = 0;
675 		}else {
676 			get_user(read_cpu, infobuf);
677 		}
678 
679 		/* Save the command for use when reading. */
680 		file->private_data = (void *)(long)cmd;
681 		break;
682 
683 	default:
684 		return -EINVAL;
685 	};
686 
687 	return 0;
688 }
689 
690 /* Function Description: open device. Mapped to user open().
691  * Return: Always 0.
692  */
693 static int
694 envctrl_open(struct inode *inode, struct file *file)
695 {
696 	file->private_data = NULL;
697 	return 0;
698 }
699 
700 /* Function Description: Open device. Mapped to user close().
701  * Return: Always 0.
702  */
703 static int
704 envctrl_release(struct inode *inode, struct file *file)
705 {
706 	return 0;
707 }
708 
709 static const struct file_operations envctrl_fops = {
710 	.owner =		THIS_MODULE,
711 	.read =			envctrl_read,
712 	.unlocked_ioctl =	envctrl_ioctl,
713 #ifdef CONFIG_COMPAT
714 	.compat_ioctl =		envctrl_ioctl,
715 #endif
716 	.open =			envctrl_open,
717 	.release =		envctrl_release,
718 };
719 
720 static struct miscdevice envctrl_dev = {
721 	ENVCTRL_MINOR,
722 	"envctrl",
723 	&envctrl_fops
724 };
725 
726 /* Function Description: Set monitor type based on firmware description.
727  * Return: None.
728  */
729 static void envctrl_set_mon(struct i2c_child_t *pchild,
730 			    const char *chnl_desc,
731 			    int chnl_no)
732 {
733 	/* Firmware only has temperature type.  It does not distinguish
734 	 * different kinds of temperatures.  We use channel description
735 	 * to disinguish them.
736 	 */
737 	if (!(strcmp(chnl_desc,"temp,cpu")) ||
738 	    !(strcmp(chnl_desc,"temp,cpu0")) ||
739 	    !(strcmp(chnl_desc,"temp,cpu1")) ||
740 	    !(strcmp(chnl_desc,"temp,cpu2")) ||
741 	    !(strcmp(chnl_desc,"temp,cpu3")))
742 		pchild->mon_type[chnl_no] = ENVCTRL_CPUTEMP_MON;
743 
744 	if (!(strcmp(chnl_desc,"vddcore,cpu0")) ||
745 	    !(strcmp(chnl_desc,"vddcore,cpu1")) ||
746 	    !(strcmp(chnl_desc,"vddcore,cpu2")) ||
747 	    !(strcmp(chnl_desc,"vddcore,cpu3")))
748 		pchild->mon_type[chnl_no] = ENVCTRL_CPUVOLTAGE_MON;
749 
750 	if (!(strcmp(chnl_desc,"temp,motherboard")))
751 		pchild->mon_type[chnl_no] = ENVCTRL_MTHRBDTEMP_MON;
752 
753 	if (!(strcmp(chnl_desc,"temp,scsi")))
754 		pchild->mon_type[chnl_no] = ENVCTRL_SCSITEMP_MON;
755 
756 	if (!(strcmp(chnl_desc,"temp,ethernet")))
757 		pchild->mon_type[chnl_no] = ENVCTRL_ETHERTEMP_MON;
758 }
759 
760 /* Function Description: Initialize monitor channel with channel desc,
761  *                       decoding tables, monitor type, optional properties.
762  * Return: None.
763  */
764 static void envctrl_init_adc(struct i2c_child_t *pchild, struct device_node *dp)
765 {
766 	int i = 0, len;
767 	const char *pos;
768 	const unsigned int *pval;
769 
770 	/* Firmware describe channels into a stream separated by a '\0'. */
771 	pos = of_get_property(dp, "channels-description", &len);
772 
773 	while (len > 0) {
774 		int l = strlen(pos) + 1;
775 		envctrl_set_mon(pchild, pos, i++);
776 		len -= l;
777 		pos += l;
778 	}
779 
780 	/* Get optional properties. */
781 	pval = of_get_property(dp, "warning-temp", NULL);
782 	if (pval)
783 		warning_temperature = *pval;
784 
785 	pval = of_get_property(dp, "shutdown-temp", NULL);
786 	if (pval)
787 		shutdown_temperature = *pval;
788 }
789 
790 /* Function Description: Initialize child device monitoring fan status.
791  * Return: None.
792  */
793 static void envctrl_init_fanstat(struct i2c_child_t *pchild)
794 {
795 	int i;
796 
797 	/* Go through all channels and set up the mask. */
798 	for (i = 0; i < pchild->total_chnls; i++)
799 		pchild->fan_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
800 
801 	/* We only need to know if this child has fan status monitored.
802 	 * We don't care which channels since we have the mask already.
803 	 */
804 	pchild->mon_type[0] = ENVCTRL_FANSTAT_MON;
805 }
806 
807 /* Function Description: Initialize child device for global addressing line.
808  * Return: None.
809  */
810 static void envctrl_init_globaladdr(struct i2c_child_t *pchild)
811 {
812 	int i;
813 
814 	/* Voltage/PowerSupply monitoring is piggybacked
815 	 * with Global Address on CompactPCI.  See comments
816 	 * within envctrl_i2c_globaladdr for bit assignments.
817 	 *
818 	 * The mask is created here by assigning mask bits to each
819 	 * bit position that represents PCF8584_VOLTAGE_TYPE data.
820 	 * Channel numbers are not consecutive within the globaladdr
821 	 * node (why?), so we use the actual counter value as chnls_mask
822 	 * index instead of the chnl_array[x].chnl_no value.
823 	 *
824 	 * NOTE: This loop could be replaced with a constant representing
825 	 * a mask of bits 5&6 (ENVCTRL_GLOBALADDR_PSTAT_MASK).
826 	 */
827 	for (i = 0; i < pchild->total_chnls; i++) {
828 		if (PCF8584_VOLTAGE_TYPE == pchild->chnl_array[i].type) {
829 			pchild->voltage_mask |= chnls_mask[i];
830 		}
831 	}
832 
833 	/* We only need to know if this child has global addressing
834 	 * line monitored.  We don't care which channels since we know
835 	 * the mask already (ENVCTRL_GLOBALADDR_ADDR_MASK).
836 	 */
837 	pchild->mon_type[0] = ENVCTRL_GLOBALADDR_MON;
838 }
839 
840 /* Initialize child device monitoring voltage status. */
841 static void envctrl_init_voltage_status(struct i2c_child_t *pchild)
842 {
843 	int i;
844 
845 	/* Go through all channels and set up the mask. */
846 	for (i = 0; i < pchild->total_chnls; i++)
847 		pchild->voltage_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
848 
849 	/* We only need to know if this child has voltage status monitored.
850 	 * We don't care which channels since we have the mask already.
851 	 */
852 	pchild->mon_type[0] = ENVCTRL_VOLTAGESTAT_MON;
853 }
854 
855 /* Function Description: Initialize i2c child device.
856  * Return: None.
857  */
858 static void envctrl_init_i2c_child(struct linux_ebus_child *edev_child,
859 				   struct i2c_child_t *pchild)
860 {
861 	int len, i, tbls_size = 0;
862 	struct device_node *dp = edev_child->prom_node;
863 	const void *pval;
864 
865 	/* Get device address. */
866 	pval = of_get_property(dp, "reg", &len);
867 	memcpy(&pchild->addr, pval, len);
868 
869 	/* Get tables property.  Read firmware temperature tables. */
870 	pval = of_get_property(dp, "translation", &len);
871 	if (pval && len > 0) {
872 		memcpy(pchild->tblprop_array, pval, len);
873                 pchild->total_tbls = len / sizeof(struct pcf8584_tblprop);
874 		for (i = 0; i < pchild->total_tbls; i++) {
875 			if ((pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset) > tbls_size) {
876 				tbls_size = pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset;
877 			}
878 		}
879 
880                 pchild->tables = kmalloc(tbls_size, GFP_KERNEL);
881 		if (pchild->tables == NULL){
882 			printk("envctrl: Failed to allocate table.\n");
883 			return;
884 		}
885 		pval = of_get_property(dp, "tables", &len);
886                 if (!pval || len <= 0) {
887 			printk("envctrl: Failed to get table.\n");
888 			return;
889 		}
890 		memcpy(pchild->tables, pval, len);
891 	}
892 
893 	/* SPARCengine ASM Reference Manual (ref. SMI doc 805-7581-04)
894 	 * sections 2.5, 3.5, 4.5 state node 0x70 for CP1400/1500 is
895 	 * "For Factory Use Only."
896 	 *
897 	 * We ignore the node on these platforms by assigning the
898 	 * 'NULL' monitor type.
899 	 */
900 	if (ENVCTRL_CPCI_IGNORED_NODE == pchild->addr) {
901 		struct device_node *root_node;
902 		int len;
903 
904 		root_node = of_find_node_by_path("/");
905 		if (!strcmp(root_node->name, "SUNW,UltraSPARC-IIi-cEngine")) {
906 			for (len = 0; len < PCF8584_MAX_CHANNELS; ++len) {
907 				pchild->mon_type[len] = ENVCTRL_NOMON;
908 			}
909 			return;
910 		}
911 	}
912 
913 	/* Get the monitor channels. */
914 	pval = of_get_property(dp, "channels-in-use", &len);
915 	memcpy(pchild->chnl_array, pval, len);
916 	pchild->total_chnls = len / sizeof(struct pcf8584_channel);
917 
918 	for (i = 0; i < pchild->total_chnls; i++) {
919 		switch (pchild->chnl_array[i].type) {
920 		case PCF8584_TEMP_TYPE:
921 			envctrl_init_adc(pchild, dp);
922 			break;
923 
924 		case PCF8584_GLOBALADDR_TYPE:
925 			envctrl_init_globaladdr(pchild);
926 			i = pchild->total_chnls;
927 			break;
928 
929 		case PCF8584_FANSTAT_TYPE:
930 			envctrl_init_fanstat(pchild);
931 			i = pchild->total_chnls;
932 			break;
933 
934 		case PCF8584_VOLTAGE_TYPE:
935 			if (pchild->i2ctype == I2C_ADC) {
936 				envctrl_init_adc(pchild,dp);
937 			} else {
938 				envctrl_init_voltage_status(pchild);
939 			}
940 			i = pchild->total_chnls;
941 			break;
942 
943 		default:
944 			break;
945 		};
946 	}
947 }
948 
949 /* Function Description: Search the child device list for a device.
950  * Return : The i2c child if found. NULL otherwise.
951  */
952 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
953 {
954 	int i, j;
955 
956 	for (i = 0; i < ENVCTRL_MAX_CPU*2; i++) {
957 		for (j = 0; j < PCF8584_MAX_CHANNELS; j++) {
958 			if (i2c_childlist[i].mon_type[j] == mon_type) {
959 				return (struct i2c_child_t *)(&(i2c_childlist[i]));
960 			}
961 		}
962 	}
963 	return NULL;
964 }
965 
966 static void envctrl_do_shutdown(void)
967 {
968 	static int inprog = 0;
969 	static char *envp[] = {
970 		"HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
971 	char *argv[] = {
972 		"/sbin/shutdown", "-h", "now", NULL };
973 	int ret;
974 
975 	if (inprog != 0)
976 		return;
977 
978 	inprog = 1;
979 	printk(KERN_CRIT "kenvctrld: WARNING: Shutting down the system now.\n");
980 	ret = call_usermodehelper("/sbin/shutdown", argv, envp, 0);
981 	if (ret < 0) {
982 		printk(KERN_CRIT "kenvctrld: WARNING: system shutdown failed!\n");
983 		inprog = 0;  /* unlikely to succeed, but we could try again */
984 	}
985 }
986 
987 static struct task_struct *kenvctrld_task;
988 
989 static int kenvctrld(void *__unused)
990 {
991 	int poll_interval;
992 	int whichcpu;
993 	char tempbuf[10];
994 	struct i2c_child_t *cputemp;
995 
996 	if (NULL == (cputemp = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON))) {
997 		printk(KERN_ERR
998 		       "envctrl: kenvctrld unable to monitor CPU temp-- exiting\n");
999 		return -ENODEV;
1000 	}
1001 
1002 	poll_interval = 5000; /* TODO env_mon_interval */
1003 
1004 	printk(KERN_INFO "envctrl: %s starting...\n", current->comm);
1005 	for (;;) {
1006 		msleep_interruptible(poll_interval);
1007 
1008 		if (kthread_should_stop())
1009 			break;
1010 
1011 		for (whichcpu = 0; whichcpu < ENVCTRL_MAX_CPU; ++whichcpu) {
1012 			if (0 < envctrl_read_cpu_info(whichcpu, cputemp,
1013 						      ENVCTRL_CPUTEMP_MON,
1014 						      tempbuf)) {
1015 				if (tempbuf[0] >= shutdown_temperature) {
1016 					printk(KERN_CRIT
1017 						"%s: WARNING: CPU%i temperature %i C meets or exceeds "\
1018 						"shutdown threshold %i C\n",
1019 						current->comm, whichcpu,
1020 						tempbuf[0], shutdown_temperature);
1021 					envctrl_do_shutdown();
1022 				}
1023 			}
1024 		}
1025 	}
1026 	printk(KERN_INFO "envctrl: %s exiting...\n", current->comm);
1027 	return 0;
1028 }
1029 
1030 static int __init envctrl_init(void)
1031 {
1032 	struct linux_ebus *ebus = NULL;
1033 	struct linux_ebus_device *edev = NULL;
1034 	struct linux_ebus_child *edev_child = NULL;
1035 	int err, i = 0;
1036 
1037 	for_each_ebus(ebus) {
1038 		for_each_ebusdev(edev, ebus) {
1039 			if (!strcmp(edev->prom_node->name, "bbc")) {
1040 				/* If we find a boot-bus controller node,
1041 				 * then this envctrl driver is not for us.
1042 				 */
1043 				return -ENODEV;
1044 			}
1045 		}
1046 	}
1047 
1048 	/* Traverse through ebus and ebus device list for i2c device and
1049 	 * adc and gpio nodes.
1050 	 */
1051 	for_each_ebus(ebus) {
1052 		for_each_ebusdev(edev, ebus) {
1053 			if (!strcmp(edev->prom_node->name, "i2c")) {
1054 				i2c = ioremap(edev->resource[0].start, 0x2);
1055 				for_each_edevchild(edev, edev_child) {
1056 					if (!strcmp("gpio", edev_child->prom_node->name)) {
1057 						i2c_childlist[i].i2ctype = I2C_GPIO;
1058 						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
1059 					}
1060 					if (!strcmp("adc", edev_child->prom_node->name)) {
1061 						i2c_childlist[i].i2ctype = I2C_ADC;
1062 						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
1063 					}
1064 				}
1065 				goto done;
1066 			}
1067 		}
1068 	}
1069 
1070 done:
1071 	if (!edev) {
1072 		printk("envctrl: I2C device not found.\n");
1073 		return -ENODEV;
1074 	}
1075 
1076 	/* Set device address. */
1077 	writeb(CONTROL_PIN, i2c + PCF8584_CSR);
1078 	writeb(PCF8584_ADDRESS, i2c + PCF8584_DATA);
1079 
1080 	/* Set system clock and SCL frequencies. */
1081 	writeb(CONTROL_PIN | CONTROL_ES1, i2c + PCF8584_CSR);
1082 	writeb(CLK_4_43 | BUS_CLK_90, i2c + PCF8584_DATA);
1083 
1084 	/* Enable serial interface. */
1085 	writeb(CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK, i2c + PCF8584_CSR);
1086 	udelay(200);
1087 
1088 	/* Register the device as a minor miscellaneous device. */
1089 	err = misc_register(&envctrl_dev);
1090 	if (err) {
1091 		printk("envctrl: Unable to get misc minor %d\n",
1092 		       envctrl_dev.minor);
1093 		goto out_iounmap;
1094 	}
1095 
1096 	/* Note above traversal routine post-incremented 'i' to accommodate
1097 	 * a next child device, so we decrement before reverse-traversal of
1098 	 * child devices.
1099 	 */
1100 	printk("envctrl: initialized ");
1101 	for (--i; i >= 0; --i) {
1102 		printk("[%s 0x%lx]%s",
1103 			(I2C_ADC == i2c_childlist[i].i2ctype) ? ("adc") :
1104 			((I2C_GPIO == i2c_childlist[i].i2ctype) ? ("gpio") : ("unknown")),
1105 			i2c_childlist[i].addr, (0 == i) ? ("\n") : (" "));
1106 	}
1107 
1108 	kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
1109 	if (IS_ERR(kenvctrld_task)) {
1110 		err = PTR_ERR(kenvctrld_task);
1111 		goto out_deregister;
1112 	}
1113 
1114 	return 0;
1115 
1116 out_deregister:
1117 	misc_deregister(&envctrl_dev);
1118 out_iounmap:
1119 	iounmap(i2c);
1120 	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++)
1121 		kfree(i2c_childlist[i].tables);
1122 
1123 	return err;
1124 }
1125 
1126 static void __exit envctrl_cleanup(void)
1127 {
1128 	int i;
1129 
1130 	kthread_stop(kenvctrld_task);
1131 
1132 	iounmap(i2c);
1133 	misc_deregister(&envctrl_dev);
1134 
1135 	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++)
1136 		kfree(i2c_childlist[i].tables);
1137 }
1138 
1139 module_init(envctrl_init);
1140 module_exit(envctrl_cleanup);
1141 MODULE_LICENSE("GPL");
1142